Glossary

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  • ABRASION

A roughening or scratching of a surface due to abrasive wear. On aluminun parts, also known as a rub marks or traffics mark.

  • ABRASIVE

(1) A hard substance used for grinding, honing, lapping, superfinishing, polishing, pressure blasting or barrel finishing. It includes natural materials such as garnet, emery, corundum and diamond, and electric-furnace products like aluminum oxide, silicon carbide and boron carbide. (2) Hard particles, such as rocks, sand or fragments of certain hard metals, that wear away a surface when they move across it under pressure.

  • ABRASIVE BELT

A coated abrasive product, in the form of a belt, used in production grinding and polishing.

  • ABRASIVE BLASTING

A process for cleaning or finishing by means of an abrasive directed at high velocity against the workpiece.

  • ABRASIVE DISK

(1) A grinding wheel that is mounted on a steel plate, with the exposed flat side being used for grinding. (2) A disk-shaped, coated abrasive product.

  • ABRASIVE WEAR

The removal of material from a surface when hard particles slide or roll across the surface under pressure. The particles may be loose or may be part of another surface in contact with the surface being worn. Contrast with the adhesive wear.

  • ACCURACY

The closeness of approach of a measurement to the true value of the quantity measured. Since the true value cannot actually measured, the most probable value from the available data, critically considered for sources of error, is used as "the truth". Contrast with precision.

  • ACICULAR FERRITE

A highly substructured nonequiaxed ferrite that forms upon continuous cooling by a mixed diffusion and shear mode of transformation that begins at a temperature slight higher than the temperature transformation range for upper bainite. It is distinguished from bainite in that it has a limited amount of carbon available; thus, there is only a small amount of carbide present.

  • ACICULAR FERRITE STEELS

Those steels having a microstructure consisting of either acicular ferrite or a mixture of acicular and equiaxed ferrite.

  • ACID

A chemical substance that yields hydrogen ions (H+) when dissolved in water. Compare with base (3).

  • ACID BOTTOM AND LINING

The inner bottom and lining of a melting furnace consisting of materials like sand, siliceous rock or silica brick that give an acid reaction at the operating temperature.

  • ACID COPPER

(1) Copper electrodeposited from an acid solution of a copper salt, usually copper sulfate. (2) T The solution referred to in (1).

  • ACID EMBRITTLEMENT

A form of hydrogen embrittlement that may be induced in some metals by acid treatment.

  • ACID STEEL

Steel melted in a furnace with an acid bottom and lining and under a slag containing an excess of an acid substance such as silica.

  • ACTIVATION

The changing of a passive surface of a metal to a chemically active state. Contrast with passivation.

  • ACTIVATION ENERGY

The energy required for initiating a metallurgical reaction; for example, plastic flow, diffusion, chemical reaction. The activation energy may be calculated from the slope of the line obtained by plotting the natural log of the reaction rate versus the reciprocal of the absolute temperature.

  • ACTIVITY

A measure of the chemical potential of a substance, where chemical potential is not equal to concentration, that allows mathematical relations equivalent to those for ideal systems to be used to correlate changes in an experimentally measured quantity to changes in chemical potential.

  • ADDITION AGENT

A substance added to a solution for the purpose of altering or controlling a process. Examples: wetting agents in acid pickles; brighteners or antipitting agents in plating solutions; and inhibitors.

  • ADHESION

Force of attraction between the molecules (or atoms) of two different phases. Contrast with cohesion.

  • ADHESIVE BONDING

A materials joining process in which an adhesive placed between faying surfaces, solidifies to bond the surfaces together.

  • ADHESIVE WEAR

The removal of material from a surface by the welding together and subsequent shearing of minute areas of two surfaces that slides across each other under pressure. In advanced stages, may lead to galling or seizing. Contrast with abrasive wear.

  • ADJUSTABLE BED

Bed of a press designed so that the die space height can be varied conveniently.

  • AGE HARDENING

Hardening by aging, usually after rapid cooling or cold working. See aging.

  • AGE SOFTENING

Spontaneous decrease of strength and hardness that takes place at room temperature in certain strain hardened alloys, especially those of aluminum.

  • AGGLOMERATING PROCESSES

Fine particles of limestone (flux) and iron ore are difficult to handle and transport because of dusting and decomposition, so the powdery material usually is processed into larger pieces. The raw material's properties determine the technique that is used by mills

  • AGING

A change in the properties of certain metals and alloys that occurs at ambient or moderately elevated temperatures after hot working or a heat treatment (quench aging in ferrous alloys, natural or artificial aging in ferrous and nonferrous alloys) or after a cold working operation (strain aging). The change in properties is often, but not always, due to a phase change (precipitation), but never involves a change in chemical composition of the metal or alloy. See also age hardening, artificial aging, interrupted aging, natural aging, overaging, precipitation hardening, precipitation head treatment, progressive aging, quench aging, step aging, strain aging.

  • AIR BEND DIE

Angle-forming dies in which the metal is formed without striking the bottom of the die. Metal contact is made at only three points in the cross section: the nose of the male die and the two edges of a V-shape die opening.

  • AIR BENDING

Bending in an air bend die.

  • AIR CLASSIFICATION

The separation of metal powder into particle-size fractions by means of an air stream of controlled velocity; an application of the principle of elutriation.

  • AIR-HARDENING STEEL

A steel containing sufficient carbon and other alloying elements to harden fully during cooling in air or other gaseous mediums from a temperature above its transformation range. The term should be restricted to steels that are capable of being hardened by cooling in air in fairly large sections, about 2 in. or more in diameter. Same as self-hardening steel.

  • AIR-LIFT HAMMER

A type of gravity drop hammer where the ram is raised for each stroke by an air cylinder. Since length of stroke may be controlled, ram velocity and thus energy delivered to the workpiece may be varied.

  • AISI (AMERICAN IRON AND STEEL INSTITUTE)

An association of North American companies that mine iron ore and produce steel products. There are 48 member companies and 150 associate members, which include customers that distribute, process, or consume steel. The AISI has reorganized into a North American steel trade association, representing the interests of Canada, Mexico, and the United States

  • ALCLAD

Composite wrought product comprised of an aluminum alloy core having on one or both surfaces a metallurgically bonded aluminum or aluminum alloy coating that is anodic to the core and thus electrically protects the core against corrosion.

  • ALKALI METAL

A metal in group IA of the periodic system-namely, lithium, sodium, potassium, rubidium, cesium and francium. They form strongly alkaline hydroxides; hence the name.

  • ALKALINE CLEANER

A material blended from alkali hydroxides and such alkaline salts as borates, carbonates, phosphates or silicates. They cleaning action may be enhanced by the addition of surface-active agents and special solvents.

  • ALKALINE EARTH METAL

A metal in group IIa of the periodic system-namely, beryllium, magnesium, calcium, strontium, barium and radium-so called because the oxides or "earths" of calcium, strontium and barium were found by the early chemists to be alkaline in reaction.

  • ALLIGATORING

The longitudinal splitting of flat slabs in a plane parallel to the rolled surface. Also called fish-mouthing.

  • ALLOTRIOMORPHIC CRYSTAL

A crystal whose lattice structure is normal but whose external surfaces are not bounded by regular crystal faces; rather, the external surfaces are impressed by contact with other crystals or another surface such as a mold wall, or are irregularly shaped because of nonuniform growth. Compare with idiomorphic crystal.

  • ALLOTROPY

A near synonym for polymorphism. Allotropy is generally restricted to describing polymorphic behavior in elements, terminal phases, and alloys whose behavior closely parallels that of the predominant constituent element.

  • ALLOWANCE

The specified difference in limiting sizes (minimum clearance or maximum interference) between mating parts, as computed arithmetically from the specified dimensions and tolerances of each part.

  • ALLOY

A substance having metallic properties and being composed of two or more chemical elements of which at least one is a metal.

  • ALLOY PLATING

The codeposition of two or more metallic elements.

  • ALLOY POWDER

A powdered metal in which each particles is composed of the same alloy.

  • ALLOY STEEL

Steel containing specified quantities of alloying elements (other than carbon and the commonly accepted amounts of manganese, copper, silicon, sulfur and phosphorus) within the limits recognized for constructional alloy steels, added to effect changes in mechanical or physical properties.

  • ALLOY STEEL

An iron-based mixture is considered to be an alloy steel when manganese is greater than 1.65percent, silicon over 0.5percent, copper above 0.6percent, or other minimum quantities of alloying elements such as chromium, nickel, molybdenum, or tungsten are present. An enormous variety of distinct properties can be created for the steel by substituting these elements in the recipe

  • ALLOY SURCHARGE

The addition to the producer's selling price included in order to offset raw material cost increases caused by higher alloy prices

  • ALLOYING ELEMENT

An element added to a metal to effect changes in properties and which remains within the metal.

  • ALLOYING ELEMENT

Any metallic element added during the making of steel for the purpose of increasing corrosion resistance, hardness, or strength. The metals used most commonly as alloying elements in stainless steel include chromium, nickel, and molybdenum

  • ALL-POSITION ELECTRODE

In are welding, a filler-metal electrode for depositing weld metal in the flat, horizontal, overhead and vertical positions.

  • ALL-WELD-METAL TEST SPECIMEN

A test specimen wherein the portion being tested is composed wholly of weld metal.

  • ALPHA FERRITE

See ferrite.

  • ALPHA IRON

The body-centered cubic form of pure iron, stable below 910�C (1670�F).

  • ALSIFER

A deoxidizer (20 Al, 40Si, 40Fe) used for steel.

  • ALTERNATE-IMMERSIONTEST

A corrosion test in which the specimens are intermittently immersed in and removed from a liquid medium at definite time intervals.

  • ALUMEL

Anickel-base alloy containing about 2.5 Mn, 2 Al and 1 Si used chiefly as a component of pyrometric thermocouples.

  • ALUMININZING

Forming an aluminum or aluminum alloy coating on a metal by hot dipping, hot spraying or diffusion.

  • ALUMINUM BOMB

A bomb-shaped container used in determining the oxygen content in liquid steel.

  • AMALGAM

An alloy of mercury with one or more other metals.

  • AMORPHOUS

Not having a crystal structure; noncrystalline.

  • AMPHOTERIC

Possessing both acidic and basic properties.

  • ANCHORRITE

A zinc-iron phosphate coating for iron and steel.

  • ANELASTICITY

The property of solids by virtue of which strain is not a single-valued function of stress in the low-stress range where no permanent set occurs.

  • ANGLE OF BITE

Inrolling metals where all the force is transmitted through the rolls, the maximum attainable angle between the roll radius at the first contact and the line of roll centers. Operating angles less than the angle of bite are called contact angles or rolling angles.

  • ANGLE OF NIP

In rolling, the angle of bite. In roll, jaw or gyratory crushing, the entrance angle formed by the tangents at the two points of contact between the working surfaces and the (assumed) spherical particle to be crushed.

  • ANGSTROM (UNIT)

A unit of linear measurement equal to 10-10m, or 0,1 nm, sometimes used to express small distances such as interatomic distances and some wavelengths.

  • ANION

A negatively charged ion; it flows to the anode in electrolysis.

  • ANISOTROPY

The characteristic of exhibiting different values of a property in different directions with respect to a fixed reference system in the material.

  • ANNEAL TO TEMPER

A final partial anneal that softens a cold worked nonferrous alloy to a specified level of hardness or tensile strength.

  • ANNEALING

A generic term denoting a treatment, consisting of heating to and holding at a suitable temperature followed by cooling at a suitable rate, used primarily to soften metallic materials, but also to simultaneously produce desired changes in other properties or in microstructure. The purpose of such changes may be, but is not confined to; improvement of machinability, facilitation of cold work, improvement of mechanical or electrical properties, and/or increase in stability of dimensions. When the term is used without qualification, full annealing is implied. When applied only for the relief of stress, the process is properly called stress relieving or stress-relief annealing. In ferrous alloys, annealing usually is done above the upper critical temperature, but the time-temperature cycles vary widely in both maximum temperature attained and in cooling rate employed, depending on composition, material condition, and results desired. When applicable, the following commercial process names should be used: black annealing, blue annealing, box annealing, bright annealing, graphitizing, in-process annealing, isothermal annealing, malleablizing, orientation annealing, process annealing, quench annealing, spheroidizing, subcritical annealing. In nonferrous alloys, annealing cycles are designed to: (a) remove part or all of the effects of cold working (recrystallization may or may not be involved); (b) cause substantially complete coalescence of precipitates from solid solution in relatively coarse form; or (c) both, depending on composition and material condition. Specific process names commercial use final annealing, full annealing, intermediate annealing, partial annealing, recrystallization annealing, stress-relief annealing, anneal to temper.

  • ANNEALING

WHAT: A heat or thermal treatment process by which a previously cold-rolled steel coil is made more suitable for forming and bending. The steel sheet is heated to a designated temperature for a sufficient amount of time and then cooled. WHY: The bonds between the grains of the metal are stretched when a coil is cold. HOW: There are two ways to anneal cold-rolled steel coils-batch and continuous: (1) Batch (Box) - Three to four coils are stacked on top of each other, and a cover is placed on top. For up to three days, the steel is heated in a non-oxygen atmosphere (so it will not rust) and slowly cooled. (2) Continuous - Normally part of a coating line, the steel is uncoiled and run through a series of vertical loops within a heater: The temperature and cooling rates are controlled to obtain the desired mechanical properties for the steel.

  • ANNEALING CARBON

Fine, apparently amorphous carbon particles formed in white cast iron and certain steels during prolonged annealing. Also called temper carbon.

  • ANNEALING TWIN

A twin formed in a crystal during recrystallization.

  • ANODE

The electrode where electrons leave an operating system such as a battery, an electrolytic cell, an x-ray tube or a vacuum tube. In the first of these, it is negative; in the other three, positive. In a battery or electrolytic cell, it is the electrode where oxidation occurs. Contrast with cathode.

  • ANODE COMPARTMENT

In an electrolytic cell, the enclosure formed by a diaphragm around the anodes.

  • ANODE COPPER

Special-shaped copper slabs, resulting from the refinement of blister copper in a reverberatory furnace, used as anodes in electrolytic refinement.

  • ANODE CORROSION

The dissolution of a metal acting as an anode.

  • ANODE EFFECT

The effect produced by polarization the anode in electrolysis. It is characterized by a sudden increase in voltage and a corresponding decrease in amperage due to the anode becoming virtually separated from the electrolyte by a gas film.

  • ANODE EFFICIENCY

Current efficiency at the anode.

  • ANODE FILM

(1) The portion of solution in immediate contact with the anode, especially if the concentration gradient is steep. (2) The outer layer of the anode itself.

  • ANODE MUD

Deposit of insoluble residue formed form the dissolution of the anode in commercial electrolysis. Sometimes called anode slime.

  • ANODE POLARIZATION

See polarization.

  • ANODIC CLEANING

Electrolytic cleaning where the works is the anode. It is also called reverse-current cleaning.

  • ANODIC COATING

A film on a metal surface resulting from an electrolytic treatment at the anode.

  • ANODIC PICKLING

Electrolytic pickling where the work is the anode.

  • ANODIC PROTECTION

Imposing an external electrical potencial to protect a metal from corrosive attack. (Applicable only to metals that show active-passive behavior.) Contrast with cathodic protection.

  • ANODIZING

Forming a conversion coating on a metal surface by anodic oxidation; most frequently applied to aluminum.

  • ANOLYTE

The electrolyte adjacent to the anode in an electrolytic cell.

  • ANTIFERROMAGNETIC MATERIAL

A material wherein interatomic forces hold the elementary atomic magnets (electron spins) of a solid in alignment, the state being similar to that of a ferro-magnetic material but with the difference that equal numbers of elementary magnets (spins) face in opposite directions and are antiparallel, causing the solid to be weakly magnetic, that is, paramagnetic, instead of ferromagnetic.

  • ANTIPITTING AGENT

An addition agent for electroplating solutions to prevent the formation of pits or large pores in the electrodeposit.

  • ANVIL

(1) In drop forging, the base of the hammer into which the sow block and lower die part are set. (2) A block of steel upon which metal is forged.

  • ANVIL CAP

Same as sow block.

  • APPARENT DENSITY

(1) The weight per unit volume of a metal powder, in contrast to the weight per unit volume of the individual particles. (2) The weight per unit volume of a porous solid, where the unit volume is determined from external dimensions of the mass. Apparent density is always less than the true density of the material itself.

  • APPARENT SUPPLY

Derived demand for steel using AISI reported steel mill shipments plus Census Bureau reported imports, less Census Bureau reported exports. Domestic market share percentages are based on this figure, which does not take into account any changes in inventory

  • APPROACH DISTANCE

The linear distance, in the direction of feed, between the point of initial cutter contact and the point of full cutter contact.

  • ARBITRATION BAR

A test bar, cast with a heat of material, used to determine chemical composition, hardness, tensile strength, and deflection and strength under transverse loading in order to establish the state of acceptability of the casting.

  • ARBOR

(1) In machine grinding, the spindle on which the wheel is mounted. (2) In machine cutting, a shaft or bar for holding and driving the cutter. (3) In founding, a metal shape embedded in green sand or dry sand cores to support the sand or the applied load during casting.

  • ARBOR PRESS

A machine used forcing arbors or mandrels into drilled or bored parts preparatory to turning or grinding. Also used for forcing bushings, shafts or pins into or out of holes.

  • ARBOR-TYPES CUTTERS

Cutters having a hole for mounting on an arbor and usually having a keyway for a driving key.

  • ARC BLOW

The swerving of an electric arc from its normal path because of magnetic forces.

  • ARC BRAZING

A brazing process in which the heat required is obtained from an electric arc.

  • ARC CUTTING

A group of cutting processes that melt the metals to be cut with the heat of an arc between an electrode and the base metal. See carbon-arc cutting, metal-arc cutting, gas tungsten-arc cutting, plasma arc cutting.

  • ARC FURNACE

A furnace in which material is heated either directly by an electric arc between an electrode and the work or indirectly by an arc between two electrodes adjacent to the material.

  • ARC GOUGING

An arc cutting procedure used to form a bevel or groove.

  • ARC MELTING

Melting metal in an electric arc furnace.

  • ARC OF CONTACT

The portion of the circumference of a grinding wheel or cutter touching the work being processed.

  • ARC TIME

The time the arc is maintained in making an arc weld. Also known as weld time.

  • ARC VOLTAGE

The voltage across any electric arc - for example, across a welding arc.

  • ARC WELDING

A group of welding processes that fuse metals together by heating them with an arc, with or without the application of pressure and with or without the use of filler metal.

  • ARGON OXYGEN DECARBURIZATION (AOD)

WHAT. A process for further refinement of stainless steel through reduction of carbon content. WHY. The amount of carbon in stainless steel must be lower than that in carbon steel or lower alloy steel (i.e., steel with alloying element content below 5percent). While electric arc furnaces (EAF) are the conventional means of melting and refining stainless steel, AOD is an economical supplement, as operating time is shorter and temperatures are lower than in EAF steelmaking. Additionally, using AOD for refining stainless steel increases the availability of the EAF for melting purposes. HOW. Molten, unrefined steel is transferred from the EAF into a separate vessel. A mixture of argon and oxygen is blown from the bottom of the vessel through the melted steel. Cleaning agents are added to the vessel along with these gases to eliminate impurities, while the oxygen combines with carbon in the unrefined steel to reduce the carbon level. The presence of argon enhances the affinity of carbon for oxygen and thus facilitates the removal of carbon

  • ARTIFACT

A feature of artificial character (such as a scratch or a piece of dust on a metallographic specimen) that can be erroneously interpreted as a real feature. In inspection, an a artifact often produces a false indication.

  • ARTIFICIAL AGING

Aging above room temperature. See aging. Compare with natural aging.

  • ATHERMAL TRANSFORMATION

A reaction that proceeds without benefit of thermal fluctuations; that is, thermal activation is not required. Such reactions are diffusionless and take place with great speed when the driving force is sufficiently high. For example, many martensitic transformations occur athermally on cooling even at relatively low temperatures, because of the progressively increasing driving force. In contrast, a reaction that occurs at constant temperature is an isothermal transformation; thermal activation is necessary in this case and the reaction proceeds as a function of time.

  • ATMOSPHERIC RISER

A riser that uses atmospheric pressure to aid feeding. Essentially a blind riser into which a small core or rod protrudes, the function of the core or rod being to provide an open passage so that the molten interior of the riser will not be under a partial vacuum when metal is withdrawn to feed the casting, but will always be under atmospheric pressure. Often called Williams riser.

  • ATOMIC FISSION

The breakup of the nucleus of an atom in which the combined weight of the fragments is less than that of original nucleus, the difference being converted to a very large energy release.

  • ATOMIC HYDROGEN WELDING

An arc welding process that fuses metals together by heating them with an electric arc maintained between two metal electrodes enveloped in a stream of hydrogen. Shielding is provided by the hydrogen, which also carries heat by molecular dissociation and subsequent recombination. Pressure may or may not be used and filler metal may or may not be used. (This process is now of limited industrial significance.)

  • ATOMIC NUMBER

The number of protons in an atomic nucleus; determines the individuality of the atom as a chemical element.

  • ATOMIC PERCENT

The number of atoms of an element in a total of 100 representative atoms of a substance.

  • ATOMIZATION

The dispersion of a molten into small particles by a rapidly moving stream of gas or liquid.

  • ATTENUATION

The fractional decrease of the intensity of energy flux, including the reduction of intensity resulting from geometrical spreading, absorption and scattering.

  • ATTRITION

WHAT. A natural reduction in work force as a result of resignations, retirements, or death. WHY. Most unionized companies cannot unilaterally reduce their employment levels to cut costs, so management must rely on attrition to provide openings that they, in turn, do not fill. Because the median ages of work forces at the integrated mills may be more than 50, an increasing number of retirements may provide these companies with added flexibility to improve their competitiveness

  • ATTRITIOUS WEAR

Wear of abrasive grains in grinding such that the sharp edges gradually become rounded. A grinding wheel that has undergone such wear usually has a glazed appearance.

  • AUSFORMING

Hot deformation of metastable austenite within controlled ranges of temperature and time that avoids formation of nonmartensitic transformation products.

  • AUSTEMPERING

A heat treatment for ferrous alloys in which a part is quenched from the austenitizing temperature at a rate fast enough to avoid formation of ferrite or pearlite and then held at a temperature just above Ms until transformation to bainite is complete.

  • AUSTENITE

A solid solution of one or more elements in face-centered cubic iron. Unless otherwise designated (such as nickel austenite), the solute is generally assumed to be carbon.

  • AUSTENITIC

The largest category of stainless steel, accounting for about 70percent of all production. The austenitic class offers the most resistance to corrosion in the stainless group, owing to its substantial nickel content and higher levels of chromium. Austenitic stainless steels are hardened and strengthened through cold working (changing the austenitic stainless steels. Excellent weldability and superior performance in very low-temperature services are additional features of this class. Applications include cooking utensils, food processing equipment, exterior architecture, equipment for the chemical industry, truck trailers, and kitchen sinks. The two most common grades are type 304 (the most widely specified stainless steel, providing corrosion resistance in numerous standard services) and type 316 (similar to 304 with molybdenum added, to increase opposition to various forms of deterioration)

  • AUSTENITIC GRAIN SIZE

The size attainedby the grains of steel when heated to the austenitic region; may be revealed by appropriate etching of cross sections after cooling to room temperature.

  • AUSTENITIC STEEL

An alloy steel whose structure is normally austenitic at room temperature.

  • AUSTENITIZING

Forming austenite by heating a ferrous alloy into the transformation range (partial austenitizing) or above the transformation range (complete austenitizing). When used without qualification, the term implies complete austenitizing.

  • AUTO STAMPING PLANT

A facility that presses a steel blank into the desired form of a car door or hood, for example, with a powerful die (pattern). The steel used must be ductile (malleable) enough to bend into shape without breaking

  • AUTOFRETTAGE

Prestressing a hollow metal cylinder the use of momentary internal pressure exceeding the yield strength.

  • AUTOGENOUS WELD

A fusion weld made without the addition of filler metal.

  • AUTOMATIC BRAZING

Brazing with equipment that brazing operation without constant observation and adjustment by a brazing operator may or may not perform the loading and unloading of the work.

  • AUTOMATIC GAUGE CONTROL

Using hydraulic roll force systems, steelmakers have the ability to control precisely their steel sheet's gauge (thickness) while it is traveling at more than 50 miles per hour through the cold mill. Using feedback or feed-forward systems, a computer's gap sensor adjusts the distance between the reduction rolls of the mill 50-60 times per second. These adjustments prevent the processing of any off-gauge steel sheet

  • AUTOMATIC PRESS

A press in which the work is fed mechanically through the press in synchronism with the press action. An automation press is an automatic press that, in addition, is provided with built-in electrical and pneumatic equipment.

  • AUTOMATIC WELDING

Welding with equipment that performs the welding operation without adjustment of the controls by an operator. The equipment may or may not load and unload the work. Compare with machine welding.

  • AUTOMATION PRESS

See automatic press.

  • AUTORADIOGRAPHY

An inspection technique in which radiation spontaneously emitted by a material is recorded photographically. The radiation is emitted by radioisotopes that are (a) produced in a metal bombarding it with neutrons, (b) added to a metal such as by alloying, or (c) contained within a cavity in a metal part. The technique serves to locate the position of the radioactive element or compound.

  • AUXILIARY ANODE

In electroplating, a supplementary anode placed in a position to raise the current density on a certain area of the cathode to get better plate distribution.

  • AVOGADRO'S NUMBER

The number of atoms (or molecules) in a mole of substance; equals 6.02252 x 1023 per mole.

  • AXIAL RAKE

For angular (not helical) flutes, the angle between a plane containing the tooth face and the axial plane through the tooth point. See sketch accompanying face mill.

  • AXIAL RELIEF

The relief or clearance behind the end cutting edge of a milling cutter.

  • AXIAL RUNOUT

For any rotating element, the total variation from a true plane of rotation, taken in a direction parallel to the axis of rotation. Compare with radial runout.

  • AXIS OF WELD

A line through the length of a weld perpendicular to the cross section at its geometric center.

  • BACK DRAFT

A reverse taper on a casting pattern or a forging die that prevents the pattern or forged stock from being removed from the cavity.

  • BACK EXTRUSION

See backward extrusion.

  • BACK RAKE

The angle on a single-point turning tool corresponding to axial rake in milling. It is the angle measured between the plane of the tool face and the reference plane and which lies in a plane perpendicular to the axis of the work material and the base of the tool. See sketch accompanying single-point tool.

  • BACK WELD

A weld deposited at the back of a single-groove weld.

  • BACKFIRE

The recession of a flame into the tip of a torch followed by immediate reappearance or complete extinction of the flame. See flashback.

  • BACKHAND WELDING

Welding in which the back of the principal hand (torch or electrode hand) of the welder faces the direction of travel. It has special significance in oxyfuel gas welding in that the flame is directed backward toward the weld bead, which provides postheating. Compare with forehand welding.

  • BACKING

(1) In grinding, the material (paper, cloth or fiber) that serves as the base for coated abrasives. (2) In welding, a material placed under or behind a joint to enhance the quality of the weld at the root. It may be a metal backing ring or strip; a pass of weld metal; or a nonmetal such as carbon, granular flux or a protective gas.

  • BACKLASH

Lost motion, play or movement in moving parts such that the driving element (as a gear) can be reversed for some angle or distance before working contact is again made with a driven element.

  • BACKOFF

A rapid withdrawal of a grinding wheel or cutting tool from contact with workpiece.

  • BACKSTEP SEQUENCE

A longitudinal welding sequence in which the direction of general progress is opposite to that of welding the individual increments.

  • BACKWARD EXTRUSION

Same as indirect extrusion. See extrusion.

  • BAGHOUSE

A chamber containing bags for filtering solids out of gases.

  • BAIL

Hoop or arched connection between the crane hook and ladle or between crane hook and mold trunnions.

  • BAINITE

A metastable aggregate of ferrite and cementite resulting from the transformation of austenite at temperatures below the pearlite range but above MS. Its appearance is feathery if formed in the upper part of the bainite transformation range; acicular, resembling tempered martensite, if formed in the lower part.

  • BAKE HARDENABLE STEEL

A cold-rolled, low-carbon sheet steel used for automotive body panel applications. Because of the steel's special processing, it has good stamping and strength characteristics, and, after paint is baked on, improved dent resistance

  • BAKING

(1) Heating to a low temperature in order to remove gases. (2) Curing or hardening surfaces coatings such as paints by exposure to heat. (3) Heating to drive off moisture, as in the baking of sand cores after molding.

  • BALANCE

(1) (dynamic) condition existing where the principal inertia axis of a body coincides with its rotational axis. (2) (static) Condition existing where the center of gravity of a body lies on its rotational axis.

  • BALL BURNISHING

(1) Same as ball sizing. (2) Removing burrs and polishing small stampings and small machined parts by tumbling in the presence of metal balls.

  • BALL MILL

A machine consisting of a rotating hollow cylinder partly filled with metal balls (usually hardened steel or white cast iron) or sometimes pebbles; used to pulverize crushed ores or other substances such as pigments.

  • BALL SIZING

Sizing and finishing a hole by forcing a ball of suitable size, finish and hardness through the hole or by using a burnishing bar or broach consisting of a series of spherical lands of gradually increasing size coaxially arranged. Also called ball burnishing, and sometimes ball broaching.

  • BAND MARK

An indentation in carbon steel sheet or strip caused by external pressure on the packaging band around cut lengths or coils; it may occur in handling, transit or storage.

  • BANDED STRUCTURE

A segregated structure consisting of alternating nearly parallel bands of different composition, typically aligned in the direction of primary hot working.

  • BANDS

(1) Hot rolled steel strip, usually produced for rerolling into thinner sheet or strip. Also known as hot bands or band steel. (2) See electron bands.

  • BAR

(1) An obsolete unit of pressure equal to 100 kPa. (2) An elongated rolled metal product that is relatively thick and narrow; most bars have simple, uniform cross sections such as rectangular, square, round, oval or hexagonal. Also known as barstock. Compare with section (3).

  • BAR END

See end loss.

  • BAR FOLDER

A machine in which a folding bar or wing is used to bend a metal sheet whose edge is clamped between the upper folding leaf and the lower stationary jaw into a narrow, sharp, close and accurate fold along the edge. It is also capable of making rounded folds such as those used in wiring. A universal folder is more versatile in that it is limited to width only by the dimensions of the sheet.

  • BARE ELECTRODE

A filler-metal arc welding electrode, in the form of a wire or rod having no coating other than that incidental to the drawing of the wire or to its preservation.

  • BARK

The decarburized layer just beneath the scale that results from heating steel in an oxidizing atmosphere.

  • BARKHAUSEN EFFECT

The sequence of abrupt changes in magnetic induction occurring when the magnetizing force acting on a ferromagnetic specimen is varied.

  • BARREL CLEANING

Mechanical or electrolytic cleaning of metal in rotating equipment.

  • BARREL FINISHING

Improving the surface finish of metal objects or parts by processing them in rotating equipment along with abrasive particles that may be suspended in a liquid.

  • BARREL PLATING

Plating articles in a rotating container, usually a perforated cylinder that operates at least partially submerged in a solution.

  • BARRELING

Convexity of the surfaces of cylindrical or conical bodies, often produced unintentionally during upsetting or as a natural consequence during compression testing.

  • BARS

Long steel products that are rolled from billets. Merchant bar and reinforcing bar (rebar) are two common categories of bars, where merchants include rounds, flats, angles, squares, and channels that are used by fabricators to manufacture a wide variety of products such as furniture, stair railings, and farm equipment. Rebar is used to strengthen concrete in highways, bridges and buildings (see Sheet Steel)

  • BARSTOCK

Same as bar.

  • BASAL PLANE

A plane perpendicular to the principal axis (c axis) in a tetragonal or hexagonal structure.

  • BASE

(1) The surface on which a singlepoint tool rests when held in a tool post. Also known as heel. See sketch accompanying single-point tool. (2) In forging-see anvil. (3) A chemical substance that yields hydroxyl ions (OH-) when dissolved in water.

  • BASE BULLION

Crude lead containing recoverable silver, with or without gold.

  • BASE METAL

(1) The metal present in the largest proportion in an alloy; brass, for example, is a copper-base alloy. (2) The metal to be brazed, cut, soldered or welded. (3) After welding, that part of the metal which was not melted. (4) A metal that readily oxidizes, or that dissolves to form ions. Contrast with noble metal (2).

  • BASIC BOTTOM AND LINING

The inner bottom and lining of a melting furnace, consisting of materials such as crushed burned dolomite magnesite, magnesite bricks or basic slag that give a basic reaction at the operating temperature.

  • BASIC OXYGEN FURNACE (BOF)

WHAT. A pear-shaped furnace, lined with refractory bricks, that refines molten iron from the blast furnace and scrap into steel. Up to 30percent of the charge into the BOF can be scrap, with hot metal accounting for the rest. WHY. BOFs, which can refine a heat (batch) of steel in less than 45 minutes, replaced open-hearth furnaces in the 1950s; the latter required five to six hours to process the metal. The BOF's rapid operation, lower cost and ease of control give it a distinct advantage over previous methods. HOW. Scrap is dumped into the furnace vessel, followed by the hot metal from the blast furnace. A lance is lowered from above, through which blows a high-pressure stream of oxygen to cause chemical reactions that separate impurities as fumes or slag. Once refined, the liquid steel and slag are poured into separate containers

  • BASIC STEEL

Steel melted in a furnace with a basic bottom and lining and under a slag containing an excess of a basic substance such as magnesia or lime.

  • BASIN

Same as pouring basin.

  • BASIS METAL

The original metal to which one or more coatings are applied.

  • BATCH

See lot.

  • BAUSCHINGER EFFECT

For both single-crystal and polycrystalline metals any change in stress-strain characteristics that can be ascribed to changes in the microscopic stress distribution within the metal, as distinguished from changes caused by strain hardening. In the narrow sense, the process whereby plastic deformation in one direction causes a reduction in yield strength when stress is applied in the opposite direction.

  • BAYER PROCESS

A process for extracting alumina from bauxite ore before the electrolytic reduction. The bauxite is digested in a solution of sodium hydroxide, which converts the alumina to soluble aluminate. After the "red mud" residue has been filtered out, aluminum hydroxide is precipitated, filtered out and calcined to alumina.

  • BEACH MARKS

Progression marks on a fatigue fracture surface that indicate successive positions of the advancing crack front. The classic appearance is of irregular elliptical or semielliptical rings, radiating outward from one or more origins.Beach marks (also known as clamshell marks or tide marks) are typically found on service fractures where the part is loaded randomly, intermittently, or with periodic variations in mean stress or alternating stress.

  • BEAD WELD

See preferred term surfacing weld.

  • BEADED FLANGE

A flange reinforced by a low ridge, used mostly around a hole.

  • BEADING

Raising a ridge or projection on sheet metal.

  • BEARING STRESS

The shear load on a mechanical joint (such as a pinned or riveted joint) divided by the effective bearing area. The effective bearing area of a riveted joint, for example, is the sum of the diameters of all rivets times the thickness of the loaded member.

  • BED

(1) The stationary portion of a press structure that usually rests on the floor or foundation, forming the support for the remaining parts of the press and the pressing load. The bolster and sometimes the lower die are mounted on the top surface of the bed. (2) For machine tools, the portion of the main frame that supports the tools, the work, or both.

  • BEILBY LAYER

A layer of metal disturbed by mechanical working presumed to be without regular crystalline structure (amorphous); originally applied to grain boundaries.

  • BEL

A unit denoting the ratio of power levels of signals or sound. The number of bels may be given as the common logarithm of the ratio of powers: n = log (p1/p2) where p1 and p2 are the initial and final power levels.

  • BELT GRINDING

Grinding with an abrasive belt.

  • BENCH PRESS

Any small press that can be mounted on a bench or table.

  • BEND ALLOWANCE

The length of the arc of the neutral axis between the tangent points of a bend.

  • BEND ANGLE

The angle through which a bending operation is performed.

  • BEND RADIUS

(1) The inside radius of a bent section. (2) The radius of a tool around which metal is bent during fabrication.

  • BEND TANGENT

A tangent point where a bending arc ceases or changes.

  • BEND TEST

A test for determining relative ductility of metal that is to be formed (usually sheet, strip, plate or wire) for determining soundness and toughness of metal (after welding, for example). The specimen is usually bent over a specified diameter through a specified angle for a specified number of cycles.

  • BENDER

Term denoting a die impression, tool or mechanical device designed to bend forging stock to conform to the general configuration of die impressions to be subsequently used.

  • BENDING BRAKE

A press brake used for bending.

  • BENDING MOMENT

The algebraic sum of the couples or the moments of the external forces, or both, to the left or right of any section on a member subjected to bending by couples or transverse forces, or both.

  • BENDING ROLLS

Two or three rolls with an adjustment for imparting a desired curvature in sheet or strip metal.

  • BENEFICIATION

Concentration or other preparation of ore for smelting.

  • BENTONITE

A colloidal claylike substance derived from the decomposition of volcanic ash composed chiefly of the minerals of the montmorillonite family. Western bentonite is slightly alkaline; southern bentonite is usually slightly acidic.

  • BESSEMER PROCESS

A process for making steel by blowing air through molten pig iron contained in a refractory lined vessel so as to remove by oxidation most of the carbon, silicon and manganese. This process is essentially obsolete in the United States.

  • BETA RAY

A ray of electrons emitted during the spontaneous disintegration of certain atomic nuclei.

  • BETA STRUCTURE

A Hume-Rothery designation for structurally analogous body-centered cubic phases (similar to beta brass) or electron compounds that have ratios of three valence electrons to two atoms. Not to be confused with a beta phase on a constitution diagram.

  • BETTS PROCESS

A process for the electrolytic refining of lead in which the electrolyte contains lead fluosilicate and fluosilicic acid.

  • BEVEL

See preferred term, corner angle, and also sketch accompanying face mill.

  • BEVEL ANGLE

The angle formed between the prepared edge of a member and a plane perpendicular to the surface of the member.

  • BEVEL FLANGING

Same as flaring.

  • BIAXIALITY

In a biaxial stress state, the ratio of the smaller to the larger principal stress. biaxial stress

  • BILLET

(1) A solid semifinished round or square product that has been hot worked by forging, rolling or extrusion; usually smaller than a bloom. (2) A general term for wrought starting stock used in making forgings or extrusions.

  • BILLET

A semi-finished steel form that is used for "long" products: bars, channels or othe structural shapes. A billet is different from a slab because of its outer dimensions billets are normally two to seven inches square, while slabs are 30-80 inches wide and 2-lO inches thick. Both shapes are generally continually cast, but they may differ greatly in their chemistry

  • BILLET MILL

A primary rolling mill used to make steel billets. binary alloy

  • BINDER

(1) In founding, a material, other than water, added to foundry sand to bind the particles together sometimes with the use of heat. (2) In powder metallurgy, a cementing medium; either a material added to the powder to increase the green strength of the compact and that is expelled during sintering or a material (usually of relatively low melting point) added to a powder mixture for the specific purpose of cementing together powder particles that alone would not sinter into a strong body.

  • BIPOLAR ELECTRODE

An electrode in an electrolytic cell that is not mechanically connected to the power supply, but is so placed in the electrolyte, between the anode and cathode, that the part nearer the anode becomes cathodic and the part nearer the cathode becomes anodic. Also called intermediate electrode.

  • BIPOLAR FIELD

A longitudinal magnetic field that creates two magnetic poles within a piece of material. Compare with circular field.

  • BISCUIT

(1) An upset blank for drop forging. (2) A small cake of primary metal (such as uranium made from uranium tetrafluoride and magnesium by bomb reduction). Compare with derby and dingot.

  • BLACK ANNEALING

Box annealing or pot annealing ferrous alloy sheet, strip or wire. See box annealing.

  • BLACK LIGHT

Electromagnetic radiation not visible to the human eye. The portion of the spectrum generally used in fluorescent inspection falls in the ultraviolet region between 330 and 400 nm, with the peak at 365 nm.

  • BLACK OXIDE

A black finish on a metal produced by immersing it in hot oxidizing salts or salt solutions.

  • BLACK PLATE

Cold-reduced sheet steel, 12-32 inches wide, that serves as the substrate (raw material) to be coated in the tin mill

  • BLACKHEART MALLEABLE

See malleable cast iron.

  • BLACKING

Carbonaceous materials such as plumbago, graphite or powdered carbon used in coating pouring ladles, molds, runners, pig beds.

  • BLADE-SETTING ANGLE

See preferred term, cone angle.

  • BLANK

(1) In forming, a piece of sheet material, produced in cutting dies, that is usually subjected to further press operations. (2) A presse presintered or fully sintered powder metallurgy compact, usually in the unfinished condition and requiring cutting, machining or some other operation to produce the final shape. (3) A piece of stock from which a forging is made; often called a slug or rnultiple.

  • BLANK CARBURIZING

Simulating the carburizing operation without introducing carbon. This is usually accomplished by using an inert material in place of the carburizing agent, or by applying a suitable protective coating to the ferrous alloy.

  • BLANK HOLDER

The part of a drawing or forming die that holds the workpiece against the draw ring to control metal flow.

  • BLANK NITRIDING

Simulating the nitriding operation without introducing nitrogen. This is usually accomplished by using an inert material in place of the nitriding agent or by applying a suitable protective coating to the ferrous alloy.

  • BLANKING

Producing desired shapes from metal to be used for forming or other operations, usually by punching.

  • BLANKING

An early step in preparing flat-rolled steel for use by an end user. A blank is a section of sheet that has the same outer dimensions as a specified part (such as a door or hood) but that has not yet been stamped. Steel processors may offer blanking for their customers to reduce their labor and transportation costs; excess steel can be trimmed prior to shipment

  • BLAST FURNACE

A shaft furnace in which solid fuel is burned with an air blast to smelt ore in a continuous operation. Where the temperature must be high, as in the production of pig iron, the air is preheated. Where the temperature can be lower, as in smelting copper, lead and tin ores, a smaller furnace is economical, and preheating of the blast is not required.

  • BLAST FURNACE

A towering cylinder lined with heat-resistant (refractory) bricks, used by integrated steel mills to smelt iron from iron ore. Its name comes from the "blast" of hot air and gases forced up through the iron ore, coke and limestone that load the furnace

  • BLASTING

Cleaning or finishing metals by impingement with abrasive particles moving at high speed and usually carried by gas or liquid or thrown centrifugally from a wheel.

  • BLEMISH

A nonspecific quality control term designating an imperfection that mars the appearance of a part but does not detract from its ability to perform its intended function.

  • BLENDING

In powder metallurgy, the thorough intermingling of powders of the same nominal composition (not to be confused with mixing).

  • BLIND RISER

A riser that does not extend through the top of the mold.

  • BLISTER

A raised area, often dome shaped, resulting from (a) loss of adhesion between a coating or deposit and the basis metal or (b) delamination under the pressure of expanding gas trapped in a metal in a near subsurface zone. Very small blisters may be called pinheads or pepper blisters.

  • BLISTER COPPER

An impure intermediate product in the refining of copper, produced by blowing copper matte in a converter, the name being derived from the large blisters on the cast surface that result from the liberation of SO2 and other gases.

  • BLOCK BRAZING

An obsolete brazing process in which the joint was heated using hot blocks.

  • BLOCK SEQUENCE

A welding sequence in which separated lengths of a continuous multiple-pass weld are partly or completely built up in cross section before intervening lengths are deposited. Compare with cascade sequence.

  • BLOCKER

The impression in the dies (often one of a series of impressions in a single die set) that imparts to the forging an intermediate shape, preparatory to forging of the final shape. Also called blocking impression.

  • BLOCKER-TYPE FORGING

A forging that approximates the general shape of the final part with relatively generous finish allowance and radii. Such forgings are sometimes specified to reduce die costs where only a small number of forgings is desired and the cost of machining each part to its final shape is not excessive.

  • BLOCKING

In forging, a preliminary operation performed in closed dies, usually hot, to position metal properly so that in the finish operation the dies will be filled correctly.

  • BLOCKING IMPRESSION

Same as blocker.

  • BLOOM

(1) A semifinished hot rolled product, rectangular in cross section produced on a blooming mill. See also billet. For steel, the width of a bloom is not more than twice the thickness, and the cross-sectional area is usually not less than about 230 cm2 (36 in.2). Steel blooms are sometimes made by forging. (2) A visible exudation or efflorescence on the surface of an electroplating bath. (3) A bluish fluorescent cast to a painted surface caused by deposition of a thin film of smoke, dust or oil. (4) A loose, flowerlike corrosion product that forms when certain metals are exposed to a moist environment.

  • BLOOM

A semi-finished steel form whose rectangular cross-section is more than eight inches. This large cast steel shape is broken down in the mill to produce the familiar I-beams, H-beams and sheet piling. Blooms are also part of the high-quality bar manufacturing process: Reduction of a bloom to a much smaller cross-section can improve the quality of the metal

  • BLOOMER

The mill or other equipment used in reducing steel ingots to blooms.

  • BLOOMING MILL

A primary rolling mill used to make blooms.

  • BLOTTER

In grinding, a disk of compressible material, usually blotting-paper stock, used between the grinding wheel and its flanges to avoid concentrated stresses.

  • BLOWHOLE

A hole in a casting or a weld caused by gas entrapped during solidification.

  • BLOWPIPE

A welding or cutting torch.

  • BLUE ANNEALING

Heating hot rolled ferrous sheet in an open furnace to a temperature within the transformation range and then cooling in air, in order to soften the metal. The formation of a bluish oxide on the surface is incidental.

  • BLUE BRITTLENESS

Brittleness exhibited by some steels after being heated to some temperature within the range of about 200 to 370 �C (400 to 700 �F), particularly if the steel is worked at the elevated temperature. Killed steels are virtually free of this kind of brittleness.

  • BLUE DIP

A solution containing a mercury compound, once widely used to deposit mercury on a metal by immersion, usually prior to silver plating.

  • BLUING

Subjecting the scale-free surface of a ferrous alloy to the action of air, steam or other agents at a suitable temperature, thus forming a thin blue film of oxide and improving the appearance and resistance to corrosion. NOTE: This term is ordinarily applied to sheet, strip or finished parts. It is used also to denote the heating of springs after fabrication in order to improve their properties.

  • BOARD HAMMER

A type of forging hammer in which the upper die and ram are attached to "boards" that are raised to the striking position by power-driven rollers and let fall by gravity. See drop hammer.

  • BOLSTER

A plate to which dies may be fastened, the assembly being secured to the top surface of a press bed. In mechanical forging, such a plate is also attached to the ram.

  • BOND

(1) In grinding wheels and other relatively rigid abrasive products, the material that holds the abrasive grains together. (2) In welding, brazing or soldering, the junction of joined parts. Where filler metal is used, it is the junction of the fused metal and the heat-affected base metal. (3) In an adhesive bonded or diffusion bonded joint, the line along which the faying surfaces are joined together.

  • BOOK MOLD

A split permanent mold hinged like a book.

  • BORE

A hole or cylindrical cavity produced by a single-point or multipoint tool other than a drill.

  • BORING

A machining method using single-point tools on internal surfaces of revolution.

  • BORT

Industrial diamond.

  • BOSH

(1) The section of a blast furnace extending upward from the tuyeres to the plane of maximum diameter. (2) A lining of quartz that builds up during the smelting of copper ores and that decreases the diameter of the furnace at the tuyeres. (3) A tank, often with sloping sides, used for washing metal parts or for holding cleaned parts.

  • BOSS

A relatively short protrusion or projection from the surface of a forging or casting, often cylindrical in shape.

  • BOTTOM BOARD

A flat base for holding the flask in making sand molds.

  • BOTTOM DRILL

A flat-ended twist drill used to convert a cone at the bottom of a drilled hole into a cylinder.

  • BOTTOM PIPE

An oxide-lined fold or cavity at the butt end of a slab, bloom or billet; formed by folding the end of an ingot over on itself during primary rolling. Bottom pipe is not pipe, in that it is not a shrinkage cavity, and in that sense, the term is a misnomer. Bottom pipe is similar to extrusion pipe. It is normally discarded when the slab, bloom or billet is cropped following primary reduction.

  • BOTTOMING TAP

A tap with a chamfer of 1 to 1l/2 threads in length.

  • BOWING

Deviation from flatness.

  • BOX ANNEALING

Annealing a metal or alloy in a sealed container under conditions that minimize oxidation. In box annealing a ferrous alloy, the charge is usually heated slowly to a temperature below the transformation range, but sometimes above or within it, and is then cooled slowly; this process is also called close annealing or pot annealing. See black annealing.

  • BOXING

Continuing a fillet weld around a corner as an extension of the principal weld. Also called an end return.

  • BRAKE

A device for bending sheet metal to a desired angle.

  • BRALE

A diamond penetrator of specified spheroconical shape used with a Rockwell hardness tester. This penetrator is used for the A, C, D and N scales for testing hard metals. Brass

  • BRAZE WELDING

A method of welding by using a filler metal having a liquidus above 450 �C (840 �F) and below the solidus of the base metals. Unlike brazing, in braze welding, the filler metal is not distributed in the joint by capillary attraction.

  • BRAZING

A group of welding processes that join solid materials together by heating them to a suitable temperature and by using a filler metal having a liquidus above 450 �C (840 �F) and below the solidus of the base materials. The filler metal is distributed between the closely fitted surfaces of the joint by capillary attraction.

  • BRAZING ALLOY

See preferred term brazing filler metal.

  • BRAZING FILLER METAL

A nonferrous filler metal used in brazing and braze welding.

  • BRAZING SHEET

Brazing filler metal in sheet form or flat-rolled metal clad with brazing filler metal on one or both sides.

  • BREAKDOWN

(1) An initial rolling or drawing operation, or a series of such operations, for the purpose of reducing a casting or extruded shape prior to the finish reduction to desired size. (2) A preliminary press-forging operation.

  • BREAKING STRESS

Same as fracture stress, part (1).

  • BREAKOUT

An accident caused by the failure of the walls of the hearth of the blast furnace, resulting in liquid iron or slag (or both) flowing uncontrolled out of the blast furnace

  • BREAKS

Creases or ridges usually in "untempered" or in aged material where the yield point has been exceeded. Depending on the origin of the break, it may be termed a cross break, a coil break, an edge break, or a sticker break.

  • BRIDGE DIE

A two-section extrusion die capable of producing tubing or intricate hollow shapes without the use of a separate mandrel. Metal separates into two streams as it is extruded past a bridge section, which is attached to the main die section and holds a stub mandrel in the die opening; the metal then is rewelded by extrusion pressure before it enters the die opening. Compare with porthole die.

  • BRIDGING

(1) Premature solidification of metal across a mold section before the metal below or beyond solidifies. (2) Solidification of slag within a cupola at or just above the tuyeres. (3) Welding or mechanical locking of the charge in a downfeed melting or smelting furnace. (4) In powder metallurgy, the formation of arched cavities in a powder mass. (5) In soldering, an unintended solder connection between two or more conductors either securely or by mere contact. Also called a crossed joint or solder short.

  • BRIGHT ANNEALING

Annealing in a protective medium to prevent discoloration of the bright surface.

  • BRIGHT DIP

A solution that produces, through chemical action, a bright surface on an immersed metal.

  • BRIGHT FINISH

A high-quality finish produced on ground and polished rolls. Suitable for electroplating.

  • BRIGHT PLATE

An electrodeposit that is lustrous in the as-plated condition.

  • BRIGHT RANGE

The range of current densities, other conditions being constant, within which a given electroplating bath produces a bright plate.

  • BRIGHTENER

An agent or combination of agents added to an electroplating bath to produce a lustrous deposit.

  • BRILLOUIN ZONES

See electron bands.

  • BRINELL HARDNESS TEST

A test for determining the hardness of a material by forcing a hard steel or carbide ball of specified diameter into it under a specified load. The result is expressed as the Brinell hardness number which is the value obtained by dividing the applied load in kilograms by the surface area of the resulting impression in square millimetres.

  • BRINELLING

Evenly spaced dents in a raceway of a rolling-element bearing that occur when the bearing assembly is subjected to a force or impact load great enough to cause the rolling elements to indent the raceway surface. Also called true brinelling. Compare with false brinelling.

  • BRIQUETTES

Small lumps are formed by pressing material together. Hot Iron Briquetting (HBI) is a concentrated iron ore substitute for scrap for use in electric furnaces

  • BRITTLE CRACK PROPAGATION

A very sudden propagation of a crack with the absorption of no energy except that stored elastically in the body. Microscopic examination may reveal some deformation even though it is not noticeable to the unaided eye.

  • BRITTLE FRACTURE

Separation of a solid accompanied by little or no macroscopic plastic deformation. Typically, brittle fracture occurs by rapid crack propagation with less expenditure of energy than for ductile fracture.

  • BRITTLENESS

The quality of a material that leads to crack propagation without appreciable plastic deformation.

  • BROACH

A bar-shaped cutting tool provided with a series of cutting edges or teeth that increase in size or change in shape from the starting to finishing end. The tool cuts in the axial direction when pushed or pulled and is used to shape either holes or outside surfaces.

  • BRONZE

A copper-rich copper-tin alloy with or without small proportions of other elements such as zinc and phosphorus. By extension, certain copperbase alloys containing considerably less tin than other alloying elements, such as manganese bronze (copperzinc plus manganese, tin and iron) and leaded tin bronze (copper-lead plus tin and sometimes zinc). Also, certain other essentially binary copper-base alloys containing no tin, such as aluminum bronze (copper-aluminum), silicon bronze (copper-silicon) and beryllium bronze (copper-beryllium). Also, trade designations for certain specific copper-base alloys that are actually brasses, such as architectural bronze (57 Cu, 40 Zn, 3 Pb) and commercial bronze (90 Cu, 10 Zn).

  • BRONZING

(1) Applying a chemical finish to copper or copper-alloy surfaces to alter the color. (2) Plating a coppertin alloy on various materials.

  • BRUSH ANODIZING

An anodizing process similar to brush plating.

  • BRUSH PLATING

Plating with a concentrated solution or gel held in or fed to an absorbing medium, pad or brush carrying the anode (usually insoluble). The brush is moved back and forth over the area of the cathode to be plated.

  • BRUSH POLISHING (ELECTROLYTIC)

A method of electropolishing in which the electrolyte is applied with a pad or brush in contact with the part to be polished.

  • BUCKLE

(1) A local waviness in metal bar or sheet, usually transverse to the direction of rolling. (2) An indentation in a casting resulting from expansion of molding sand into the mold cavity.

  • BUCKLING

Producing a bulge, bend, bow, kink or other wavy condition by compressively stressing a beam, column, plate, bar or sheet.

  • BUCKY DIAPHRAGM

An x-ray scatter-reducing device originally intended for medical radiography but also applicable to industrial radiography in some circumstances. Thin strips of lead, with their width held parallel to the primary radiation, are used to absorb scattered radiation preferentially; the array of strips is in motion during exposure, to prevent formation of a pattern on the film.

  • BUFF SECTION

A number of fabric, paper or leather disks with concentric center holes held together by various types of sewing to provide degrees of flexibility or hardness. These sections are assembled to make wheels for polishing.

  • BUFFER

A substance whose purpose is to maintain a constant hydrogen ion concentration in water solutions even where acid or alkalis are added. Each buffer has a characteristic limited range of pH over which it is effective.

  • BUFFING

Developing a lustrous surface by contacting the work with a rotating buffing wheel.

  • BUFFING WHEEL

Buff sections assembled to the required face width for use on a rotating shaft between flanges. Sometimes called buff.

  • BUILDER

A material, such as an alkali, a buffer or a water softener, added to soap or synthetic surface-active agent to produce a mixture having enhanced detergency. Examples: (1) alkalis-caustic soda, soda ash and trisodium phosphate; (2) buffers-sodium metasilicate and borax; and (3) water softeners-sodium tripoly-phosphate, sodium tetraphosphate, sodium hexametaphosphate and ethylene diamine tetraacetic acid.

  • BUILDUP

Excessive electrodeposition that occurs on high-current-density areas, such as corners or edges.

  • BUILDUP SEQUENCE

The order in which weld beads are deposited, generally designated in cross section as shown in the accompanying illustration.

  • BUILT-UP EDGE

Chip material adhering to the tool face adjacent to the cutting edge during cutting.

  • BULGING

Expanding the walls of a cup, shell or tube with an internally expanded segmented punch or a punch composed of air, liquids or semiliquids such as waxes, rubber and other elastomers.

  • BULL BLOCK

A machine with a power- driven revolving drum for cold drawing wire through a drawing die as the wire winds around the drum.

  • BULLDOZER

A horizontal machine, usually mechanical, having two bull gears with eccentric pins, two connecting links to a ram, and dies to perform bending, forming and punching of narrow plate and bars. Railroad car sills are formed with a bulldozer;

  • BULLION

(1) A semirefined alloy containing sufficient precious metal to make recovery profitable. (2) Refined gold or silver, uncoined.

  • BULL'S-EYE STRUCTURE

The microstructure of malleable or ductile cast iron when graphite nodules are surrounded by a ferrite layer in a pearlitic matrix.

  • BUMPER

A machine used for packing molding sand in a flask by repeated Jarring or Jolting. Bumping

  • BURNED DEPOSIT

A dull, nodular electrodeposit resulting from excessive current density. Burned-on sand

  • BURNING

(1) Permanently damaging a metal or alloy by heating to cause either incipient melting or intergranular oxidation. See ouerheating. (2) In grinding, getting the work hot enough to cause discoloration or to change the microstructure by tempering or hardening. Burnishing

  • BURN-OFF

(1) Unintentional removal of an autocatalytic deposit from a non- conducting substrate, during subsequent electroplating operations, owing to the application of excessive current or a poor contact area. (2) Removal of volatile lubricants such as metallic stearates from metal powder compacts by heating immediately prior to sintering. (3) See melting rate.

  • BURR

(1) A turned-over edge on work resulting from cutting, punching or grinding. (2) A rotary tool having teeth similar to those on hand files.

  • BURR

The very subtle ridge on the edge of strip steel left by cutting operations such as slitting, trimming, shearing, or blanking. For example, as a steel processor trims the sides of the sheet steel parallel or cuts a sheet of steel into strips, its edges will bend with the direction of the cut (see Edge Rolling)

  • BURRING

Same as deburring.

  • BUSHELING

Steel scrap consisting of sheet clips and stampings from metal production. This term arose from the practice of collecting the material in bushel baskets through World War II

  • BUSHING

A bearing or guide.

  • BUSTER

A pair of shaped dies used to combine preliminary forging operations such as edging and blocking, or to loosen the scale.

  • BUTLER FINISH

A semilustrous metal finish composed of fine, uniformly distributed parallel lines, usually produced with a soft abrasive wheel it is similar in appearance to the traditional hand-rubbed finish on silver.

  • BUTT JOINT

A joint between two abutting members lying approximately in the same plane. A welded butt joint may contain a variety of grooves. See groove weld.

  • BUTT SEAM WELDING

See seam welding

  • BUTT WELD PIPE

The standard pipe used in plumbing. Heated skelp is passed continuously through welding rolls, which form the tube and squeeze the hot edges together to make a solid weld

  • BUTT WELDING

Welding a butt joint.

  • BUTTERING

A form of surfacing in which one or more layers of weld metal are deposited on the groove face of one member (for example, a high-alloy weld deposit on steel base metal that is to be welded to a dissimilar base metal). The buttering provides a suitable transition weld deposit for subsequent completion of the butt weld.

  • BUTTON

(1) A globule of metal remaining in an assaying crucible or cupel after fusion has been completed. (2) That part of a weld that tears out in the destructive testing of spot, seam or projection welded specimens.

  • CAKE

(1) A copper or copper alloy casting rectangular in cross section used for rolling into sheet or strip. (2) A coalesced mass of unpressed metal powder.

  • CALCINATION

Heating ores, concentrates, precipitates or residues to decompose carbonates, hydrates or other compounds.

  • CALOMEL ELECTRODE (CALOMEL HALF CELL)

A secondary reference electrode of the composition: Pt/Hg-Hg2CI2/KCI solution. For 1.0N KCI solution, its potential versus a hydrogen electrode at 25 �C and one atmosphere is + 0.281 V.

  • CALORIZING

Imparting resistance to oxidation to an iron or steel surface by heating in aluminum powder at 800 to 1000 �C (1472 to 1832 �F).

  • CAM PRESS

A mechanical press in which one or more of the slides are operated by cams; usually a doubleaction press in which the blankholder slide is operated by cams through which the dwell is obtained.

  • CAMBER

(1) Deviation from edge straightness, usually referring to the greatest deviation of side edge from a straight line. (2) Sometimes used to denote crown in rolls where the center diameter has been increased to compensate for deflection caused by the rolling pressure.

  • CANNING

(1) A dished distortion in a flat or nearly flat surface, sometimes referred to as oil canning. (2) Enclosing a highly reactive metal within one relatively inert for the purpose of hot working without undue oxidation of the active metal.

  • CAPACITY

Normal ability to produce steel in a given time period. This rating should include maintenance requirements, but because such service is scheduled to match the needs of the machinery (not those of the calendar), a mill might run at more than 100percent of capacity one month and then fall well below rated capacity as maintenance is performed

  • CAPILLARY ATTRACTION

The combined force of adhesion and cohesion that causes liquids, including molten metals, to flow between very closely spaced solid surfaces, even against gravity.

  • CAPPED STEEL

A type of steel similar to rimmed steel, usually cast in a bottletop ingot mold, in which the application of a mechanical or a chemical cap renders the rimming action incomplete by causing the top metal to solidify. The surface condition of capped steel is much like that of rimmed steel, but certain other characteristics are intermediate between those of rimmed steel and those of semikilled steel.

  • CAPPING

The partial or complete separation of a powder metallurgy compact into two or more portions by cracks that originate near the edges of the punch faces and that proceed diagonally into 'he compact.

  • CARBIDE

A compound of carbon with one or more metallic elements.

  • CARBIDE TOOLS

Cutting or forming tools, usually made from tungsten, titanium, tantalum, or niobium carbides, or a combination of them, in a matrix of cobalt, nickel, or other metals. Carbide tools are characterized by high hardnesses and compressive strengths and may be coated to improve wear resistance.

  • CARBON DIOXIDE WELDING

Gas metalarc welding using carbon dioxide as the shielding gas.

  • CARBON EDGES

Carbonaceous deposits in a wavy pattern along the edges of a sheet or strip; also known as snaky edges.

  • CARBON ELECTRODE

A carbon or graphite rod used in carbon-arc equipment, such as in carbon-arc welding or cutting torches.

  • CARBON EQUIVALENT

(1) For cast iron, an empirical relationship of the total carbon, silicon and phosphorus contents expressed by the formula: CE = TC + 1/3(si + P) (2) For rating of weldability: CE = C + Mn 6 + Cr + Mo + V6 5 + Ni +CU. 15

  • CARBON POTENTIAL

A measure of the ability of an environment containing active carbon to alter or maintain, under prescribed conditions, the carbon level of the steel. NOTE: In any particular environment, the carbon level attained will depend on such factors as temperature, time and steel composition.

  • CARBON RESTORATION

Replacing the carbon lost in the surface layer from previous processing by carburizing this layer to substantially the original carbon level. Sometimes called recarburizing.

  • CARBON STEEL

steel having no specified minimum quantity for any alloying element (other than the commonly accepted amounts of manganese, silicon and copper) and that contains only an incidental amount of any element other than carbon, silicon, manganese, copper, sulfur and phosphorus.

  • CARBON STEEL

Steel that has properties made up mostly of the element carbon and which relies on the carbon content for structure. Most of the steel produced in the world is carbon steel

  • CARBONITRIDING

A case hardening process in which a suitable ferrous material is heated above the lower transformation temperature in a gaseous atmosphere of such composition as to cause simultaneous absorption of carbon and nitrogen by the surface and, by diffusion, create a concentration gradient. The process is completed by cooling at a rate that produces the desired properties in the workpiece.

  • CARBONIZATION

Conversion of an organic substance into elemental carbon. (Should not be confused with carburization).

  • CARBONYL POWDER

A metal powder prepared by the thermal decomposition of a metal carbonyl.

  • CARBURIZING

Absorption and diffusion of carbon into solid ferrous alloys by heating, to a temperature usually above Ac3, in contact with a suitable carbonaceous material. A form of case hardening that produces a carbon gradient extending inward from the surface, enabling the surface layer to be hardened either by quenching directly from the carburizing temperature or by cooling to room temperature, then reaustenitizing and quenching. carburizing flame

  • CASCADE SEQUENCE

welding sequence in which a continuous multiple-pass weld is built up by depositing weld beads in overlapping layers, usually laid in a backstep sequence. Compare with block sequence.

  • CASE

That portion of a ferrous alloy, extending inward from the surface, whose composition has been altered so that it can be case hardened. Typically considered to be the portion of the alloy (a) whose composition has been measurably altered from the original composition, (b) that appears dark on an etched cross section, or (c) that has a hardness, after hardening, equal to or greater than a specified value. Contrast with core (2).

  • CASE HARDENING

A generic term covering several processes applicable to steel that change the chemical composition of the surface layer by absorption of carbon, nitrogen, or a mixture of the two and, by diffusion, create a concentration gradient. The processes commonly used are carburizing and quench hardening; cyaniding, nitriding; and carbonitriding. The use of the applicable specific process name is preferred.

  • CASING

Casing is the structural retainer for the walls of oil and gas wells, and accounts for 75percent (by weight) of OCTG shipments. Casing is used to prevent contamination of both the surrounding water table and the well itself. Casing lasts the life of a well and is not usually removed when a well is closed

  • CASS TEST

Abbreviation for copper accelerated salt spray test.

  • CASSETTE

A lighttight holder, used to contain radiographic films during exposure to x-rays or gamma rays, that may or may not contain intensifying or filter screens, or both. A distinction is often made between a cassette, which has positive means for ensuring contact between screens and film and is usually rigid, and an exposure holder, which is rather flexible.

  • CAST

See die proof.

  • CAST IRON

A generic term for a large family of cast ferrous alloys in which the carbon content exceeds the solubility of carbon in austenite at the eutectic temperature. Most cast irons contain at least 2 percent carbon, plus silicon and sulfur, and may or may not contain other alloying elements. For the various forms gray cast iron, white cast iron, malleable cast iron and ductile cast iron, the word "cast" is often left out, resulting in "gray iron", "white iron", "malleable iron" and "ductile iron", respectively.

  • CAST STEEL

Steel in the form of castings.

  • CAST STRUCTURE

The me/allographic structure of a casting evidenced by shape and orientation of grains and by segregation of impurities.

  • CAST-ALLOY TOOL

A cutting tool made by casting a cobalt-base alloy and used at machining speeds between those for high speed steels and sintered carbides.

  • CASTING

(1) An object at or near finished shape obtained by solidification of a substance in a mold. (2) Pouring molten metal into a mold tn produce an object of desired shape.

  • CASTING COPPER

Fire-refined tough pitch copper usually cast from melted secondary metal into ingot bars only, and used for making foundry castings but not wrought products.

  • CASTING SHRINKAGE

(1) Liquid shrinkage-the reduction in volume of liquid metal as it cools to the liquidus. (2) Solidification shrinkage-the reduction in volume of metal from the beginning to ending of solidification. (3) Solid shrinkage-the reduction in volume of metal from the solidus to room temperature.

  • CASTING STRAINS

Strains in a casting caused by casting stresses that develop as the casting cools.

  • CASTING STRESSES

Residual stresses set up when the shape of a casting impedes contraction of the solidified casting during cooling.

  • CATALYST

A substance capable of changing the rate of a reaction without itself undergoing any net change.

  • CATASTROPHIC FAILURE

Sudden failure of a component or assembly that frequently results in extensive secondary damage to adjacent components or assemblies.

  • CATHODE

The electrode where electrons enter an operating system such as a battery, an electrolytic cell, an x-ray tube or a vacuum tube. In the first of these, it is positive; in the other three, negative. In a battery or electrolytic cell, it is the electrode where reduction occurs. Contrast with anode.

  • CATHODE COMPARTMENT

In an electrolytic cell, the enclosure formed by a diaphragm around the cathode.

  • CATHODE COPPER

Copper deposited at the cathode in electrolytic refining.

  • CATHODE EFFICIENCY

Current efficiency at the cathode.

  • CATHODE FILM

The portion of solution in immediate contact with the cathode during electrolysis.

  • CATHODIC CLEANING

Electrolytic cleaning where the work is the cathode.

  • CATHODIC PICKLING

Electrolytic pickling where the work is the cathode.

  • CATHODIC PROTECTION

Partial or complete protection of a metal from corrosion by making it a cathode, using either a galvanic or impressed current. Contrast with anodic protection.

  • CATHOLYTE

The electrolyte adjacent to the cathode in an electrolytic cell; in a divided cell, the portion on the cathode side of the diaphragm.

  • CATION

A positively charged ion; it flows to the cathode in electrolysis.

  • CATIONIC DETERGENT

A detergent in which the cation is the active part.

  • CAUSTIC CRACKING

A form of stress-corrosion cracking most frequently encountered in carbon steels or ironchromium-nickel alloys that are exposed to concentrated hydroxide solutions at temperatures of 200 to 250 �C (400 to 480 �F).

  • CAUSTIC DIP

A strongly alkaline solution into which metal is immersed for etching, for neutralizing acid or for removing organic materials such as grease or paints.

  • CAVITATION

The formation and instantaneous collapse of innumerable tiny voids or cavities within a liquid subjected to rapid and intense pressure changea. Cavitation produced by ultrasonic radiation is sometimes used to give violent localized agitation. That caused by severe turbulent flow often leads to cavitation damage.

  • CAVITATION DAMAGE

Erosion of a solid surface through the formation and collapse of cavities in an adjacent liquid.

  • CAVITATION EROSION

See preferred term, cavitation damage.

  • CELL FEED

The material supplied to the cell in the electrolytic production of metals. Cementation

  • CEMENT COPPER

Impure copper recovered by chemical deposition when iron (most often shredded steel scrap) is brought into prolonged contact with a dilute copper sulfate solution.

  • CEMENTED CARBIDE

A solid and coherent mass made by pressing and sintering a mixture of powders of one or more metallic carbides and a much smaller amount of a metal, such as cobalt, to serve as a binder.

  • CEMENTITE

A compound of iron and carbon, known chemically as iron carbide and having the approximate chemical formula Fe3C. It is characterized by an orthorhombic crystal structure. When it occurs as a phase in steel, the chemical composition will be altered by the presence of manganese and other carbide-forming elements.

  • CENTER DRILLING

Drilling a short, conical hole in the end of a workpiece - the hole to be used to center the workpiece for turning on a lathe.

  • CENTERING PLUG

A plug fitting both spindle and cutter to ensure concentricity of the cutter mounting.

  • CENTERLESS GRINDING

Grinding the outside or inside of a workpiece mounted on rollers rather than on centers. The workpiece may be in the form of a cylinder or the frustum of a cone.

  • CENTRIFUGAL CASTING

A casting made by pouring metal into a mold that is rotated or revolved.

  • CERAMIC TOOLS

Cutting tools made from fused, sintered or cemented metallic oxides.

  • CEREAL

An organic binder, usually corn flour.

  • CERMET

A powder metallurgy product consisting of ceramic particles bonded with a metal.

  • C-FRAME PRESS

Same as gap-frame press.

  • CG IRON

Same as compacted graphite cast iron.

  • CHAFING FATIGUE

Fatigue initiated in a surface damaged by rubbing against another body. See fretting.

  • CHAIN-INTERMITTENT FILLET WELDING

Depositing a line of intermittent fillet welds on each side of a member at a joint so that the increments on one side are essentially opposite those on the other. Contrast with staggeredintermittent fillet welding.

  • CHAMFER

(1) A beveled surface to eliminate an otherwise sharp corner. (2) A relieved angular cutting edge at a tooth corner.

  • CHAMFER ANGLE

(1) The angle between a reference surface and the bevel. (2) On a milling cutter, the angle between a beveled surface and the axis of the cutter.

  • CHAMFERING

Making a sloping surface on the edge of a member. Also called beveling. See bevel angle.

  • CHAPLET

Metal support that holds a core in place within a mold; molten metal solidifies around a chaplet and fuses it into the finished casting.

  • CHARACTERISTIC RADIATION

High-intensity single-wavelength x-rays, characteristic of the element emitting the rays, that appear in addition to continuous "white" radiation whenever the element is bombarded with electrons whose energy exceeds a specific critical value that is different for each element.

  • CHARGE

(1) The materials fed into a furnace. (2) Weights of various liquid and solid materials put into a furnace during one feeding cycle.

  • CHARGE

The act of loading material into a vessel. For example, iron ore, coke and limestone are charged into a Blast Furnace; a Basic Oxygen Furnace is charged with scrap and hot metal

  • CHARGING

(1) For a lap, impregnating the surface with fine abrasive. (2) Placing materials into a furnace.

  • CHARGY TEST

A pendulum-type single blow impact test in which the specimen, usually notched, is supported at both ends as a simple beam and broken by a falling pendulum. The energy absorbed, as determined by the subsequent rise of the pendulum, is a measure of impact strength or notch toughness. Contrast with Izod test.

  • CHASE

To make a series of cuts each, except the first, following in the path of the cut preceding it, as in chasing a thread.

  • CHATTER

In machining or grinding, (1) a vibration of the tool, wheel or workpiece producing a wavy surface on the work and (2) the finish produced by such vibration.

  • CHECKED EDGES

Sawtooth edges seen after hot rolling and/or cold rolling.

  • CHECKERS

In a chamber associated with a metallurgical furnace, bricks stacked openly so that heat may be absorbed from the combustion products and later transferred to incoming air when the direction of flow is reversed.

  • CHECKS

Numerous, very fine cracks in a coating or at the surface of a metal part. Checks may appear during processing or during service and are most often associated with thermal treatment or thermal cycling. Also called check marks, checking, heat checks.

  • CHEEK

The intermediate section of a flask that is used between the cope and the drag when molding a shape that requires more than one parting plane.

  • CHELATING AGENT

A substance used in metal finishing to control or eliminate certain metallic ions present in undesirable quantities.

  • CHEMICAL DEPOSITION

The precipitation or plating-out of a metal from solutions of its salts through the introduction of another metal or reagent to the solution.

  • CHEMICAL MACHINING

Removing metal stock by controlled selective chemical dissolution.

  • CHEMICAL METALLURGY

See process metallurgy.

  • CHEMICAL POLISHING

Improving the surface luster of a metal by chemical treatment.

  • CHEMICALLY PRECIPITATED POWDER

Metal powder produced as a precipitate by chemical displacement.

  • CHEVRON PATTERN

A fractographic pattern of radial marks (shear ledges) that looks like nested letters "V" sometimes called a herringbone pattern. Chevron patterns are typically found on brittle fracture surfaces in parts whose widths are considerably greater than their thicknesses. The points of the chevrons can be traced back to the fracture origin.

  • CHILL

(1) A metal or graphite insert embedded in the surface of a sand mold or core or placed in a mold cavity to increase the cooling rate at that point. (2) White iron occurring on a gray or ductile iron casting, such as the chill in the wedge test. Compare with inverse chill.

  • CHINESE SCRIPT

The angular microstructural form suggestive of Chinese writing and characteristic of the constituents a(Al-Fe-Si) and a(Al-Fe-Mn-Si) in cast aluminum alloys. A similar microstructure is found in cast magnesium alloys containing silicon as Mg2Si.

  • CHIP BREAKER

(1) Notch or groove in the face of a tool parallel to the cutting edge, to break the continuity of the chips. (2) A step formed by an adjustable component clamped to the face of the cutting tool.

  • CHIPPING

(1) Removing seams and other surface imperfections in metals manually with a chisel or gouge, or by a continuous machine, before further processing. (2) Similarly, removing excessive metal.

  • CHIPS

Pieces of material removed from a workpiece by cutting tools or an abrasive medium.

  • CHLORINATION

(1) Roasting ore in contact with chlorine or a chloride salt to produce Chlorides. (2) Removing dissolved gases and entrapped oxides by passing chlorine gas through molten metal such as aluminum and magnesium.

  • CHROMADIZING

Improving paint adhesion on aluminum or aluminum alloys, mainly aircraft skins, by treatment with a solution of chromic acid. Also called chromodizing, Chromatizing. Not to be confused with chromating, chromizing.

  • CHROMATE TREATMENT

A treatment of metal in a solution of a hexavalent chromium compound to produce a conversion coating consisting of trivalent and hexavalent chromium compounds.

  • CHROMATING

Performing a chromate treatment.

  • CHROME PICKLE

(1) Producing a chromate conversion coating on magnesium for temporary protection or for a paint base. (2) The solution that produces the conversion coating.

  • CHROMEL

(1) A 90Ni-10Cr alloy used in thermocouples. (2) A series of nickelchromium alloys, some with iron, used for heat-resistant applications.

  • CHROMIUM (CR)

An alloying element that is the essential stainless steel raw material for conferring corrosion resistance. A film that naturally forms on the surface of stainless steel self-repairs in the presence of oxygen if the steel is damaged mechanically or chemically, and thus prevents corrosion from occurring

  • CHROMIZING

A surface treatment at elevated temperature, generally carried out in pack, vapor or salt bath, in which an alloy is formed by the inward diffusion of chromium into the base metal.

  • CHUCK

A device for holding work or tools on a machine so that the part can be held or rotated during machining or grinding.

  • CHUCKING LUG

A projection forged or cast onto a part to act as a positive means of driving or locating when the part is being machined.

  • CIRCLE GRINDING

Either cylindrical or internal grinding, the preferred terms.

  • CIRCLE SHEAR

A shearing machine with two rotary disk cutters mounted on parallel shafts driven in unison and equipped with an attachment for cutting circles where the desired piece of material is inside the circle. It cannot be employed to cut circles where the desired material is outside the circle.

  • CIRCORED

WHAT. A gas-based process developed by Lurgi Metallurgie in Germany to produce DRI or HBI (see Direct Reduced Iron and Hot Briquetted Iron). HOW. The two-stage method yields fines with a 93percent iron content. Iron ore fines pass first through a circulating fluidized-bed reactor, and subsequently through a bubbling fluidized-bed reactor

  • CIRCULAR FIELD

The magnetic field that (a) surrounds a nonmagnetic conductor of electricity, (b) is completely contained within a magnetic conductor of electricity or (c) both exists within and surrounds a magnetic conductor. Generally applied to the magnetic field within any magnetic conductor resulting from a current being passed through the part or through a section of the part. Compare with bipolar field.

  • CLAD METAL

A composite metal containing two or three layers that have been bonded together. The bonding may have been accomplished by co-rolling welding, casting, heavy Chemical de- position or heavy electroplating.

  • CLADDING

WHAT. Method of applying a stainless steel coating to carbon steel or lower-alloy steel (i.e., steel with alloying element content below 5percent). WHY. To increase corrosion resistance at lower initial cost than exclusive use of stainless steel. HOW. By 1) welding stainless steel onto carbon steel, 2) pouring melted stainless steel around a solid carbon steel slab in a mold, or 3) placing a slab of carbon steel between two plates of stainless steel and bonding them by rolling at high temperature on a plate mill

  • CLAMSHELL MARKS

Same as beach marks.

  • CLASSIFICATION

(1) The separation of ores into fractions according to size and specific gravity, generally in accordance with Stokes' law of sedimentation. (2) Separation of a metal powder into fractions according to particle size.

  • CLAY

An earthy or stony mineral aggregate consisting essentially of hydrous silicates of alumina, and which is plastic when sufficiently pulverized and wetted, rigid when dry, and vitreous when fired at a sufficiently high temperature. Clay minerals most commonly used in the foundry are montmorillonites and kaolinites.

  • CLEANUP ALLOWANCE

See finish allowance.

  • CLEARANCE

(1) The gap or space between two mating parts. (2) Space provided between the relief of a cutting tool and the surface that has been cut.

  • CLEARANCE ANGLE

The angle between a plane containing the flank of the tool and a plane passing through the cutting edge in the direction of relative motion between the cutting edge and work. See sketches accompanying face-mill and single-point tool.

  • CLEARANCE FIT

Any of various classes of fit between mating parts where there is a positive allowance (gap) between the parts, even when they are made to the respective extremes of individual tolerances that ensure the tightest fit between the parts. Contrast with interference fit.

  • CLEAVAGE

The splitting (fracture) of a crystal on a crystallographic plane of low index. Cleavage fracture

  • CLEAVAGE PLANE

A characteristic crystallographic plane or set of planes on which cleavage fracture easily occurs.

  • CLIMB CUTTING

Analogous to climb milling.

  • CLIMB MILLING

Milling in which the cutter moves in the direction of feed at the point of contact.

  • CLIP AND SHAVE

In forging, a dual operation in which one cutting surface in the clipping die removes the flash and then another shaves and sizes the piece.

  • CLOSE ANNEALING

Same as box annealing.

  • CLOSE TOLERANCE FORGING

A forging held to unusually close dimensional tolerances. Often, little or no machining is required after forging.

  • CLOSED DIE FORGING

See impression die forging.

  • CLOSED DIES

Forging or forming impression dies designed to restrict the flow of metal to the cavity within the die set, as opposed to open dies, in which there is little or no restriction to lateral flow.

  • CLOSED PASS

A pass of metal through rolls where the bottom roll has a groove deeper than the bar being rolled and the top roll has a collar fitting into the groove, thus producing the desired shape free from flash or fin.

  • CLOUDBURST TREATMENT

A form of shot peening.

  • CLUSTER MILL

A rolling mill where each of the two working rolls of small diameter is supported by two or more backup rolls.

  • CO2 WELDING

See carbon dioxide welding

  • COALESCED COPPER

Massive oxygenfree copper made by briquetting ground, brittle cathode Copper, then sintering the briquettes in a pressurized reducing atmosphere, followed by hot working.

  • COALESCENCE

(1) The union of particles of a dispersed phase into larger units, usually effected at temperatures- below the fusion point. (2) In welding, brazing or soldering, the union of two or more components into a single body, which usually involves melting of a filler metal or of the base metal.

  • COARSENING

An increase in the grain size, usually, but not necessarily, by grain growth

  • COATED ABRASIVE

An abrasive product, sandpaper being an example, in which a layer of abrasive particles is firmly attached to a paper, cloth or fiber backing by means of glue or synthetic-resin adhesive.

  • COATED ELECTRODE

See preferred term, lightly coated electrode

  • COAXING

Improvement of the fatigue strength of a specimen by the application of a gradually increasing stress amplitude, usually starting below the fatigue limit

  • COEFFICIENT OF ELASTICITY

Same as modulus of elasticity

  • COERCIVE FORCE

The magnetizing force that must be applied in the direction opposite to that of the previous magnetizing force in order to reduce magnetic flux density to zero; thus, a measure of the magnetic retentivity of magnetic materials.

  • COGGING MILL

A blooming mill.

  • COHERENCY

The continuity of lattice of precipitate and parent phase (solvent) maintained by mutual strain and not separated by a phase boundary.

  • COHERENT PRECIPITATE

A crystalline precipitate that forms from solid solution with an orientation that maintains continuity between the crystal lattice of the precipitate and the lattice of the matrix, usually accompanied by some strain in both lattices. Because the lattices fit at the interface between precipitate and matrix there is no discernible phase boundary.

  • COHESION

Force of attraction between the molecules (or atoms) within a single phase. Contrast with adhesion.

  • COHESIVE STRENGTH

(1) The hypothetical stress causing tensile fracture without plastic deformation. (2) The stress corresponding to the forces between atoms. (3) Same as technical

  • COHESIVE STRENGTH

(4) Same as disruptive strength

  • COIL BREAKS

Creases or ridges in sheet or strip that appear as parallel lines across the direction of rolling, and that generally extend the full width of the sheet or strip.

  • COILS

Steel sheet that has been wound. A slab, once rolled in a hot-strip mill, is more than one-quarter mile long; coils are the most efficient way to store and transport sheet steel

  • COIN SILVER

An alloy containing 90 percent silver, with copper being the usual alloying element.

  • COINING

(1) A closed-die squeezing operation, usually performed cold, in which all surfaces of the work are confined or restrained, resulting in a well-defined imprint of the die upon the work. (2) A restriking operation used to sharpen or change an existing radius or profile. (3) The final pressing of a sintered powder metallurgy compact to obtain a definite surface configuration (not to be confused with re-pressing or sizing).

  • COKE

WHAT. The basic fuel consumed in blast furnaces in the smelting of iron. Coke is processed form of coal. About 1,000 pounds of coke are needed to process a ton of pig iron, an amount which represents more than 50percent of an integrated steel mill's total energy use. WHY. Metallurgical coal burns sporadically and reduces into a sticky mass. Processed coke, however, burns steadily inside and out, and is not crushed by the weight of the iron ore in the blast furnace. HOW. Inside the narrow confines of the coke oven, coal is heated without oxygen for 18 hours to drive off gases and impurities

  • COKE OVEN BATTERY

A set of ovens that process coal into coke. Coke ovens are constructed in batteries of 10-100 ovens that are 20 feet tall, 40 feet long, and less than two feet wide. Coke, batteries, because of the exhaust fumes emitted when coke is pushed from the oven, often are the dirtiest area of a steel mill complex

  • COLD CHAMBER MACHINE

A die-casting machine where the metal chamber and plunger are not heated.

  • COLD EXTRUSION

See impact; extrusion.

  • COLD HEADING

Working metal at room temperature in such a manner that the cross-sectional area of a portion or all of the stock is increased.

  • COLD INSPECTION

A visual (usually final) inspection of forgings for visible imperfections, dimensions, weight, and surface condition at room temperature. The term may also be used to describe certain nondestructive tests such as magnetic particle, dye penetrant and sonic inspection.

  • COLD LAP

Wrinkled markings on the surface of an ingot, caused by incipient freezing of the surface while the liquid is still in motion; results from too low a pouring temperature. See also cold shut (1)

  • COLD MILL

A mill for cold rolling sheet or strip.

  • COLD PRESSING

Forming a powder met- allurgy compact at a temperature low enough to avoid sintering, usually room temperature. Contrast with hot pressing.

  • COLD REDUCTION

WHAT. Finishing mills roll cold coils of pickled hot-rolled sheet to make the steel thinner, smoother, and stronger, by applying pressure, rather than heat. HOW. Stands of rolls in a cold-reduction mill are set very close together and press sheet of steel from one-quarter inch thick into less than an eighth of an inch, while more than doubling its length

  • COLD ROLLED SHEETS

A mill product produced from a hot rolled pickled coil that has been given substantial cold reduction at room temperature. The resulting product usually requires further processing to make it suitable for most common applications. The usual end product is characterized by improved surface, greater uniformity in thickness and improved mechanical properties compared to hot rolled sheet.

  • COLD SHORTNESS

Brittleness that exists in some metals at temperatures below the recrystallization temperature.

  • COLD SHOT

A portion of the surface of an ingot or casting showing premature solidification; caused by splashing of molten metal onto a cold mold wall during pouring.

  • COLD SHUT

(1) A discontinuity that appears on the surface of cast metal as a result of two streams of liquid meeting and failing to unite. (2) A lap on the surface of a forging or billet that was closed without fusion during de- formation. (3) Freezing of the top surface of an ingot before the mold is full.

  • COLD TREATMENT

Exposing to suitable subzero temperatures for the purpose of obtaining desired conditions or properties such as dimensional or microstructural stability. When the treatment involves the transformation of retained austenite, it is usually followed by tempering.

  • COLD TRIMMING

Removing flash or excess metal from the forging in a trimming press when the forging is at room temperature.

  • COLD WELDING

A solid state welding process in which pressure is used at room temperature to produce coalescence of metals with substantial de- formation at the weld. Compare hot pressure welding, diffusion welding, and forge welding.

  • COLD WORK

Permanent strain in a metal accompanied by strain hardening.

  • COLD WORKING

Deforming metal plastically under conditions of temperature and strain rate that induce strain hardening. Usually, but not necessarily, conducted at room temperature. Contrast with hot working.

  • COLD WORKING (ROLLING)

WHAT. Changes in the structure and shape of steel achieved through rolling, hammering, or stretching the steel at a low temperature (often room temperature). WHY. To create a permanent increase in the hardness and strength of the steel. HOW. The application of forces to the steel causes changes in the composition that enhance certain properties. In order for these improvements to be sustained, the temperature must be below a certain range, because the structural changes are eliminated by higher temperatures

  • COLD-ROLLED STRIP (SHEET)

Sheet steel that has been pickled and run through a cold-reduction mill. Strip has a final product width of approximately 12 inches, while sheet may be more than 80 inches wide. Cold-rolled sheet is considerably thinner and stronger than hot-rolled sheet, so it will sell for a premium (see Sheet Steel)

  • COLLAPSIBILITY

The requirement that a sand mold or core break down under the pressure and temperature of casting in order to avoid hot tears, or to facilitate the separation of sand and casting.

  • COLLET

A split sleeve used to hold work or tools during machining or grinding.

  • COLOR BUFFING

Producing a final high luster by buffing. Sometimes called "coloring". Coloring

  • COLUMNAR STRUCTURE

A coarse structure of parallel elongated grains formed by unidirectional growth, most often observed in castings, but sometimes in structures resulting from diffusional growth accompanied by a solid-state transformation.

  • COMBINATION DIE

(1) A die-casting die having two or more different cavities for different castings. (2) For forming, see compound die.

  • COMBINATION MILL

An arrangement of a continuous mill for roughing, and a guide mill or looping mill for shaping.

  • COMBINED CARBON

The part of the total carbon in steel or cast iron that is present as other than free caroon.

  • COMBINED CYANIDE

The cyanide of a metal-cyanide complex ion.

  • COMBINED STRESSES

Any state of stress that cannot be represented by a single component of stress; that is, one that is more complicated than simple tension, compression or shear. Comminution

  • COMMUTATOR-CONTROLLED WELDING

Spot or projection welding in which several electrodes, in simultaneous contact with the work, function progressively under the control of an electrical commutating device.

  • COMPACT

An object produced by the compression of metal powder, generally while confined in a die, with or without the inclusion of nonmetallic constituents. See also compound compact and composite compact.

  • COMPACTED GRAPHITE CAST IRON

Cast iron having a graphite shape intermediate between the flake form typical of gray cast iron and the spherical form of fully spherulitic ductile cast iron. Also known as CG iron or vermicular iron, compacted graphite cast iron is produced in a manner similar to ductile cast iron, but using a technique that inhibits the formation of fully spherulitic graphite nodules.

  • COMPLETE FUSION

Fusion that has occurred over the entire base-metal surfaces exposed for welding.

  • COMPLEX ION

An ion that may be formed by the addition reaction of two or more other ions.

  • COMPLEXING AGENT

A substance that is an electron donor and that will combine with a metal ion to form a soluble complex ion.

  • COMPONENT

(1) One of the elements or compounds used to define a chemical (or alloy) system, including all phases, in terms of the fewest substances possible. (2) One of the individual parts of a vector as referred to a system of coordinates.

  • COMPOSITE COMPACT

A powder metallurgy compact consisting of two or more adhering layers of different metals or alloys with each layer retaining its original identity.

  • COMPOSITE ELECTRODE

A welding electrode made from two or more distinct components, at least one of which is filler metal. A composite electrode may exist in any of various physical forms, such as stranded wires, filled tubes or covered wire.

  • COMPOSITE JOINT

A joint in which welding is used in conjunction with mechanical joining. composite material

  • COMPOSITE PLATE

An electrodeposit consisting of layers of at least two different compositions.

  • COMPOSITE STRUCTURE

A structural member (such as a panel, plate, pipe or other shape) that is built up by bonding together two or more distinct components, each of which may be made of a metal, alloy, nonmetal or composite material. Examples of composite structures include: honeycomb panels, clad plate, electrical contacts, sleeve bearings, carbide-tipped drills or lathe tools, and weldments constructed of two or more different alloys.

  • COMPOUND COMPACT

A powder metallurgy compact consisting of mixed metals, the particles of which are joined by pressing or sintering, or both, with each metal particle retaining substantially its original composition.

  • COMPOUND DIE

Any die so designed that it performs more than one operation on a part with one stroke of the press, such as blanking and piercing where all functions are performed simultaneously within the confines of the particular blank size being worked.Compressibility

  • COMPRESSION RATIO

In powder metallurgy, the ratio of the volume of the loose powder to the volume of the compact made from it.

  • COMPRESSIVE STRENGTH

The maximum compressive stress that a material is capable of developing, based on original area of cross section. If a material fails in compression by a shattering fracture, the compressive strength has a very definite value. If a mater al does not fail in compression by shattering fracture, the value obtained for compressive strength is a arbitrary value depending upon the degree of distortion that is regarded as indicating complete failure of the material.

  • CONCAVE FILLET WELD

A fillet weld having a concave face.

  • CONCENTRATION

A process for enrichment of an ore in valuable mine content by separation and removal waste material, or gangue.

  • CONCENTRATION POLARIZATION

That part of the total polarization that caused by changes in the activity the potential -determining components of the electrolyte.

  • CONCURRENT HEATING

Using a second source of heat to supplement the primary heat in cutting or welding.

  • CONDITIONING HEAT TREATMENT

A preliminary heat treatment used to prepare a material for a desired reaction to a subsequent heat treatment. For the term to be meaningful, the exact heat treatment must be specified.

  • CONGRUENT MELTING

An isothermal or isobaric melting in which both the solid and liquid phases have the same composition throughout the transformation.

  • CONGRUENT TRANSFORMATION

An isothermal or isobaric phase change in which both of the phases concerned have the same composition throughout the process.

  • CONSTANTAN

A group of copper-nickel alloys containing 45 to 60 percent copper with minor amounts of iron and manganese and characterized by relatively constant electrical resistivity irrespective of temperature; used in resistors and thermocouples.

  • CONSTITUENT

(1) One of the ingredients that make up a chemical system. (2) A phase or combination of phases that occur in a characteristic configuration in an alloy microstructure.

  • CONSTITUTION DIAGRAM

A graphical representation of the temperature and composition limits of phase fields in an alloy system as they actually exist under the specific conditions of heating or cooling (synonymous with phase diagram). A constitution diagram may be an equilibrium diagram, an approximation to an equilibrium diagram or a representation of metastable conditions or phases. Compare with equilibrium diagram.

  • CONSTRAINT

Any restriction that occurs to the transverse contraction normally associated with a longitudinal tension, and that hence causes a secondary tension in the transverse direction; usually used in connection with welding. Contrast with restraint.

  • CONSUMABLE ELECTRODE

A general term for any arc-welding electrode made chiefly of filler metal. Use of specific names such as covered electrode, bare electrode, flux-cored electrode and lightly coated electrode is preferred.

  • CONSUMABLE ELECTRODE REMELTING

A process for refining metals in which an electric current passes between an electrode made of the metal to be refined and an ingot of the refined metal, which is contained in a watercooled mold. As a result of the passage of electric current, droplets of molten metal form on the electrode and fall to the ingot. The refining action occurs from contact with the atmosphere, vacuum or slag through which the drop falls. See electroslag remelting and vacuum arc remelting.

  • CONSUMPTION

Measures the physical use of steel by end users. Steel consumption estimates, unlike steel demand figures, account for changes in inventories

  • CONTACT FATIGUE

Cracking and subsequent pitting of a surface subjected to alternating Hertzian stresses such as those produced under rolling contact or combined rolling and sliding. The phenomenon of contact fatigue is encountered most often in rolling-element bearings or in gears, where the surface stresses are high due to the concentrated loads and are repeated many times during normal operation.

  • CONTACT PLATING

A metal plating process where the plating current is provided by galvanic action between the work metal and a second metal, without the use of an external source of current.

  • CONTACT POTENCIAL

The potential difference at the junction of two dissimilar substances.

  • CONTACT SCANNING

In ultrasonic inspection, a planned systematic movement of the beam relative to the object being inspected, the search unit being in contact with and coupled to this object by a thin film of coupling material.

  • CONTAINER

The chamber into which an ingot or billet is inserted prior to extrusion. The container for backward extrusion of cups or cans is sometimes called a die.

  • CONTINUOUS CASTING

A casting technique in which a cast shape is continuously withdrawn through the bottom of the mold as it solidifies, so that its length is not determined by mold dimensions. Used chiefly to produce semifinished mill products such as billets, blooms, ingots, slabs and tubes. See also strand casting.

  • CONTINUOUS CASTING

WHAT. A method of pouring steel directly from the furnace into a billet, bloom, or slab directly from its molten form. WHY. Continuous casting avoids the need for large, expensive mills for rolling ingots into slabs. Continuous cast slabs also solidify in a few minutes versus several hours for an ingot. Because of this, the chemical composition and mechanical properties are more uniform. HOW. Steel from the BOF or electric furnace is poured into a tundish (a shallow vessel that looks like a bathtub) atop the continuous caster. As steel carefully flows from the tundish down into the water-cooled copper mold of the caster, it solidifies into a ribbon of red-hot steel. At the bottom of the caster, torches cut the continuously flowing steel to form slabs or blooms

  • CONTINUOUS MILL

A rolling mill consisting of a number of stands of synchronized rolls (in tandem) in which metal undergoes successive reductions as it passes through the various stands.

  • CONTINUOUS PHASE

In an alloy or portion of an alloy containing more than one phase, the phase that forms the matrix in which the other phase or phases are present as isolated units.

  • CONTINUOUS PRECIPITATION

Precipitation from a supersaturated solid solution in which the precipitate particles grow by long-range diffusion without recrystallization of the matrix. Continuous precipitates grow from nuclei distributed more or less uniformly throughout the matrix. They usually are randomly oriented, but may form a Widmanstatten structure. Also called general precipitation. Compare with discontinuous precipitation, localized precipitation.

  • CONTINUOUS WELD

A weld extending continuously from one end of a joint to the other; where the joint is essentially circular, completely around the joint. Contrast with intermittent weld.

  • CONTOUR MACHINING

Machining of irregular surfaces, such as those generated in tracer turning, tracer boring and tracer milling.

  • CONTOUR MILLING

Milling of irregular surfaces.

  • CONTRACT SALES

Steel products committed to customers through price agreements extending 3-12 months. About one-half of all flat-rolled steel is sold on this basis, primarily because the auto companies sign agreements to cover at least one year's model. Price increases that the steel mills might announce during the year do not generally affect the revenues from the contract side of the business

  • CONTROLLED COOLING

Cooling from an elevated temperature in a predetermined manner, to avoid hardening, cracking, or internal damage, or to produce desired microstructure or mechanical properties.

  • CONTROLLED-PRESSURE CYCLE

A forming cycle during which the hydraulic pressure in the forming cavity is controlled by an adjustable cam that is coordinated with the punch travel.

  • CONVENTIONAL FORGING

A forging characterized by design complexity and tolerances that fall within the broad range of general forging practice.

  • CONVENTIONAL MILLING

Milling in which the cutter moves in the direction opposite to the feed at the point of contact.

  • CONVENTIONAL STRAIN

See strain.

  • CONVENTIONAL STRESS

See stress.

  • CONVERSION COATING

A coating consisting of a compound of the surface metal, produced by chemical or electrochemical treatments of the metal. (Examples are chromate coatings on zinc, cadmium, magnesium and aluminum, and oxides and phosphate coatings on steel.) Converter

  • CONVERSION COST

Resources spent to process material in a single stage, from one type to another. The costs of converting iron ore to hot metal or pickling hot-rolled coil can be isolated for analysis

  • CONVERTER / PROCESSOR

Processes steel into a more finished state, such as pipe, tubing and cold-rolled strip, before selling it to end users. Such steel generally is not sold on contract, making the converter segment of the mills' revenues more price sensitive than their supply contracts to the auto manufacturers

  • CONVEX FILLET WELD

A fillet weld having a convex face.

  • COOLANT

In metal cutting, the preferred term is cutting fluid.

  • COOLING CURVE

A curve showing the relation between time and temperature during the cooling of a material.

  • COOLING STRESSES

Residual stresses resulting from nonuniform distribution of temperature during cooling.

  • COOLING TABLE

Same as hot bed.

  • COORDINATION NUMBER

(1) Number of atoms or radicals coordinated with the central atom in a complex covalent compound. (2) Number of nearest neighboring atoms to a selected atom in crystal structure.

  • COPPER ACCELERATED SALT SPRAY TEST

An accelerated corrosion test for some electrodeposits and for anodic coatings on aluminum. Often referred to as CASS test.

  • COPPER BRAZING

A term improperly used to denote joining with a copperbase filler metal. See preferred terms brazing and braze welding.

  • COPPERHEAD

A reddish spot in a porcelain enamel coating caused by iron pickup during enameling, iron oxide left on poorly cleaned basis metal, or burrs on iron or steel basis metal that protrude through the coating and are oxidized during firing.

  • CORE

(1) A specially formed material inserted in a mold to shape the interior or other part of a casting that cannot be shaped as easily by the pattern. (2) In a ferrous alloy prepared for case hardening, that portion of the alloy that is not part of the case. Typically considered to be the portion that (a) appears light on an etched cross section, (b) has an essentially unaltered chemical composition, or (c) has a hardness, after hardening, less than a specified value

  • CORE BLOWER

A machine for making foundry cores using compressed air to blow and pack the sand into the core box.

  • CORE ROD

The part of a die used to produce a hole in a powder metallurgy compact.

  • CORED BAR

A powder metallurgy compact of bar shape, the interior of which has been melted by passage of electricity.

  • COREX

WHAT. COREX is a coal-based smelting process that yields hot metal or pig iron. The output can be used by integrated mills or EAF mills. HOW. The process gasifies non-coking coal in a smelting reactor, which also produces liquid iron. The gasified coal is fed into a shaft furnace, where it removes oxygen from iron ore lumps, pellets or sinter; the reduced iron is then fed to the smelting reactor

  • CORNER ANGLE

On face milling cutters, the angle between an angular cutting edge of a cutter tooth and the axis of the cutter, measured by rotation into an axial plane. See sketch accompanying face mill.

  • CORNER JOINT

A joint between two members located approximately at right angles to each other in the form of an "L".

  • CORONA

In spot welding, an area sometimes surrounding the nugget at the faying surfaces, where solid state welding occurs. Corona contributes variably to over-all bond strength, depending on the size of the corona and the degree of solid state bonding achieved.

  • CORRODKOTE TEST

An accelerated corrosion test for electrodeposits.

  • CORROSION

The deterioration of a metal by chemical or electrochemical reaction with its environment.

  • CORROSION

The gradual degradation or alteration of steel caused by atmosphere, moisture other agents

  • CORROSION EMBRITTLEMENT

The severe loss of ductility of a metal resulting from corrosive attack, usually intergranular and often not visually apparent.

  • CORROSION FATIGUE

Cracking produced by the combined action of repeated or fluctuating stress and a corrosive environment.

  • CORRUGATING

Forming sheet metal into a series of straight parallel alternate ridges and grooves by using a rolling mill equipped with matched roller dies or by using a press brake equipped with special-shaped punch and die.

  • CORRUGATIONS

Transverse ripples caused by a variation in strip shape during hot or cold reduction.

  • CORUNDUM

Natural abrasive of the aluminum oxide type that has higher purity than emery.

  • COTTRELL PROCESS

Removal of solid particulates from gases with electrostatic precipitation.

  • COULOMETER

An electrolytic cell arranged to measure the quantity of electricity by the chemical action produced in accordance with Faraday's law.

  • COUNTERBLOW HAMMER

A forging hammer in which both the ram and anvil are driven simultaneously toward each other by air or steam pistons.

  • COUNTERBORING

Drilling or boring a flat-bottomed hole, often concentric with other holes.

  • COUNTERLOCK

A jog in the mating surfaces of dies to prevent lateral die shifting from side thrusts developed in forging irregular-shaped pieces.

  • COUNTERSINKING

Forming a flaring depression around the top of a hole for deburring, for receiving the head of a fastener or for receiving a center.

  • COUNTERVAILED DUTY

The amount of subsidies the foreign producer receives from its government is t basis for the subsidy rate by which the subsidy is offset, or "countervailed," the higher import duties. Procedurally, a countervailing duty works the same as antidumping; however, it is the basis upon which relief is calculated that differs

  • COUPLING

The degree of mutual interaction between two or more element, resulting from mechanical, acoustical or electrical linkage.

  • COUPON

A piece of metal from which test specimen is to be prepared-offer an extra piece (as on a casting or forging) or a separate piece made for test purposes (such as a test weldment).

  • COVER HALF

The stationary half of a diecasting die.

  • COVERED ELECTRODE

A composite filler metal welding electrode, consisting of a bare wire or a metal-cored electrode plus a covering sufficient to provide layer of slag on deposited weld metal. The covering often contains materials that provide shielding during welding, deoxidizers for the weld metal, and arc stabilization; it ma also contain alloying elements or other additives for the weld metal.

  • COVERING POWER

The ability of a solution to give a satisfactory plate a very low current densities, a condition that would exist in recesses and pits. This term suggests an ability to cover, but not necessarily to build up, a uniform coating, while throwing power suggests ability to get a uniform thickness on an irregularly shaped object.

  • CRATER

(1) In machining, a depression in a cutting tool face eroded by chip contact. (2) In arc welding, a depression at the termination of a bead or in the weld pool beneath the electrode.

  • CRATER CRACK

A crack, often star shaped, that forms in the crater of a weld bead, usually during cooling after welding.

  • CREEP

Time-dependent strain occurring under stress. The creep strain occurring at a diminishing rate is called primary creep; that occurring at a minimum and almost constant rate, secondary creep; that occurring at an accelerating rate, tertiary creep.

  • CREEP LIMIT

(1) The maximum stress that will cause less than a specified quantity of creep in a given time. (2) The maximum nominal stress under which the creep strain rate decreases continuously with time under constant load and at constant temperature. Sometimes used synonymously with creep strength.

  • CREEP RECOVERY

Time-dependent strain after release of load in a creep test.

  • CREEP STRENGTH

(1) The constant nominal stress that will cause a specified quantity of creep in a given time at constant temperature. (2) The constant nominal stress that will cause a specified rate of secondary creep at constant temperature.

  • CREEP-RUPTURE TEST

Same as stressrupture test

  • CREVICE CORROSION

A type of concentration-cell corrosion; corrosion caused by the concentration or depletion of dissolved salts, metal ions, oxygen or other gases, and such, in crevices or pockets remote from the principal fluid stream, with a resultant building up of differential cells that ultimately cause deep pitting.

  • CRITICAL CIRCUMSTANCES

Massive imports of less-than-fair-value merchandise over a relatively short peri which justifies a retroactive application of duties up to 90 days prior to a prelim anti-dumping or countervailing duty determination

  • CRITICAL COOLING RATE

The rate of continuous cooling required to prevent undesirable transformation. For steel, it is the minimum rate at which austenite must be continuously cooled to suppress transformations above the M8 temperature.

  • CRITICAL CURRENT DENSITY

In an electrolytic process, a current density at which an abrupt change occurs in an operating variable or in the nature of an electrodeposit or electrode film.

  • CRITICAL POINT

(1) The temperature or pressure at which a change in crystal structure, phase or physical properties occurs. Same as transformation temperature. (2) In an equilibrium diagram, that specific value of composition, temperature and pressure, or combinations thereof, at which the phases of a heterogeneous system are in equilibrium.

  • CRITICAL SHEAR STRESS

The shearing stress required to cause slip in a designated slip direction on a given slip plane. It is called the critical resolved shear stress if the shearing stress is induced by tension or compression forces acting on the crystal.

  • CRITICAL STRAIN

The strain just sufficient to cause recrystallization; because the strain is small, usually only a few percent, recrystallization takes place from only a few nuclei, which produces a recrystallized structure consisting of very large grains.

  • CRITICAL TEMPERATURE

(1) Synonymous with critical point if the pressure is constant. (2) The temperature above which the vapor phase cannot be condensed to liquid by an increase in pressure.

  • CRITICAL TEMPERATURE RANGES

Synonymous with transformation ranges, which is the preferred term.

  • CRONING PROCESS

A shell molding process utilizing a phenolic resin binder. Sometimes referred to as "C" process.

  • CROP

(1) An end portion of an ingot that is cut off as scrap. (2) To shear a bar or billet.

  • CROSS BREAKS

Same as coil breaks.

  • CROSS FORGING

Preliminary working of forging stock in flat dies to develop mechanical properties, particularly in the center portions of heavy sections.

  • CROSS ROLLING

The rolling of sheet or plate so that the direction of rolling is about 90� from the direction of a previous rolling.

  • CROSS-COUNTRY MILL

A rolling mill in which the mill stands are so arranged that their tables are parallel with a transfer (or crossover) table connecting them. They are used for rolling structural shapes, rails and any special form of bar stock not rolled in the ordinary bar mill.

  • CROSSED JOINT

See bridging (5).

  • CROSS-ROLL STRAIGHTENER

A machine having paired rolls of special design for straightening round bars or tubes, the pass being made with the work parallel to the axes of the rolls. Cross-wire weld

  • CROWN

(1) A contour on a sheet or roll where the thickness or diameter increases from edge to center. (2) The top section of a press structure where the cylinders and other working parts may be mounted. Also called dome, head or top platen.

  • CRUCIBLE

A vessel or pot, made of a refractory substance or of a metal with a high melting point, used for melting metals or other substances.

  • CRUSH

(1) Buckling or breaking of a section of a casting mold due to incorrect register when the mold is closed. (2) An indentation in the surface of a casting due to displacement of sand when the mold was closed.

  • CRUSH FORMING

Shaping a grinding wheel by forcing a rotating metal roll into its face so as to reproduce the desired contour.

  • CRUSHING TEST

(1) A radial compressive test applied to tubing, sintered-metal bearings or other similar products for determining radial crushing strength (maximum load in compression). (2) An axial compressive test for determining quality of tubing, such as soundness of weld in welded tubing.

  • CRYSTAL

A solid composed of atoms, ions or molecules arranged in a pattern that is repetitive in three dimensions.

  • CRYSTAL ORIENTATION

See orientation.

  • CRYSTALLINE FRACTURE

A pattern of brightly reflecting crystal facets on the fracture surface of a polycrystal-line metal and resulting from cleavage fracture of many individual crystals. Contrast with fibrous fracture, silky fracture.

  • CRYSTALLIZATION

(1) The separation, usually from a liquid phase on cooling, of a solid crystalline phase. (2) Sometimes erroneously used to explain fracturing that actually has occurred by fatigue.

  • CUBIC PLANE

A plane perpendicular to any one of the three crystallographic axes of the cubic (isometric) system; the Miller indices are {100}.

  • CULVERT PIPE

Heavy gauge, galvanized steel that is spiral-formed or riveted into corrugated pipe, which is used for highway drainage applications

  • CUP

(1) Sheet-metal part, the product of the first step in deep drawing. (2) Any cylindrical part or shell closed at one end.

  • CUP FRACTURE (CUP-AND-CONE FRACTURE)

A mixed-mode fracture, often seen in tensile test specimens of a ductile material, where the central portion undergoes plane-strain fracture and the surrounding region undergoes plane-stress fracture. It is called a cup fracture (or cup-and-cone fracture) because one of the mating fracture surfaces looks like a miniature cup-that is, it has a central depressed flat-face region surrounded by a shear lip; the other fracture surface looks like a miniature truncated cone.

  • CUPELLATION

Oxidation of molten lead containing gold and silver to produce lead oxide, thereby separating the precious metals from the base metal.

  • CUPOLA

A cylindrical vertical furnace for melting metal, especially cast iron, by having the charge come in contact with the hot fuel, usually metallurgical coke.

  • CUPPING

(1) The first step in deep drawing. (2) The fracture of severely worked rods or wire where one end has the appearance of a cup and the other that of a cone.

  • CURIE TEMPERATURE

The temperature of magnetic transformation below which a metal or alloy is ferromagnetic and above which it is paramagnetic.

  • CURLING

Rounding the edge of sheet metal into a closed or partly closed loop.

  • CURRENT DECAY

In spot, seam or projection welding, the controlled reduction of the welding current from its peak amplitude to a lower value to prevent excessively rapid cooling of the weld nugget.

  • CURRENT EFFICIENCY

The proportion of current used in a given process to accomplish a desired result; in electroplating, the proportion used in depositing or dissolving metal.

  • CUSHION

Same as die cushion.

  • CUT

(1) In castings, rough spots or areas of excess metal caused by erosion of the mold or core surface by metal flow. (2) In powder metallurgy, same as fraction.

  • CUT EDGE

A mechanically sheared edge obtained by slitting, shearing or blanking.

  • CUT-AND-CARRY METHOD

Stamping method where the part remains attached to the strip or is forced back into the strip to be fed through the succeeding stations of a progressive die.

  • CUTOFF WHEEL

A thin abrasive wheel for severing or slotting any material or part.

  • CUTTING DOWN

Removing roughness or irregularities of a metal surface by abrasive action. Cutting edge

  • CUTTING FLUID

A fluid used in metal cutting to improve finish, tool life or dimensional accuracy. On being flowed over the tool and work, the fluid reduces the friction, the heat generated and the tool wear and prevents galling. It conducts the heat away from the point of generation and also serves to wash the chips away.

  • CUTTING SPEED

The linear or peripheral speed of relative motion between the tool and workpiece in the principal direction of cutting.

  • CUTTING TIP

The part of a cutting torch from which gas issues.

  • CUT-TO-LENGTH

Process to uncoil sections of flat-rolled steel and cut them into a desired length. Product that is cut to length is normally shipped flat-stacked

  • CYANIDE COPPER

Copper electrodeposited from an alkali-cyanide solution containing a complex ion made up of univalent copper and the cyanide radical; also, the solution itself Cyanide slimes

  • CYANIDING

A case hardening process in which a ferrous material is heated above the lower transformation range in a molten salt containing cyanide to cause simultaneous absorption of carbon and nitrogen at the surface and, by diffusion, create a concentration gradient. Quench hardening completes the process.

  • CYCLE ANNEALING

An annealing process employing a predetermined and closely controlled time-temperature cycle to produce specific properties or microstructures.

  • CYLINDRICAL GRINDING

Grinding the outer cylindrical surface of a rotating part.

  • DAMPING CAPACITY

The ability of a material to absorb vibration (cyclical stresses) by internal friction, converting the mechanical energy into heat.

  • DAYLIGHT

The maximum clear distance between the pressing surfaces of a hydraulic press with the surfaces in their usable open position. Where a bolster is supplied, it shall be considered the pressing surface. See also shut height.

  • DC CASTING

Same as direct chill casting.

  • DEAD CENTER

(1) A stationary center to hold rotating work. (2) Either of the two points in the path of a moving crank or connecting rod that lie at the ends of its stroke.

  • DEAD ROAST

A roasting process for complete elimination of sulfur. Also known as sweet roast.

  • DEAD SOFT

A temper of nonferrous alloys and some ferrous alloys corresponding to the condition of minimum hardness and tensile strength produced by full annealing.

  • DECALESCENCE

A phenomenon, associated with the transformation of alpha iron to gamma iron on the heating (superheating) of iron or steel, revealed by the darkening of the metal surface owing to the sudden decrease in temperature caused by the fast absorption of the latent heat of transformation. Contrast with recalescence.

  • DECARBURIZATION

Loss of carbon from the surface layer of a carbon-containing alloy due to reaction with one or more chemical substances in a medium that contacts the surface. decomposition potential

  • DEEP DRAWING

Forming deeply recessed parts by forcing sheet metal to undergo plastic flow between dies, usually without substantial thinning of the sheet.

  • DEEP ETCHING

Severe macroetching.

  • DEFECT

A departure of any quality characteristic from its intended (usually specified) level that is severe enough to cause the product or service not to fulfill its anticipated function. According to ANSI standards, defects are classified according to severity: Very serious defects lead directly to severe injury or catastrophic economic loss. Serious defects lead directly to significant injury or significant economic loss. Major defects are related to major problems with respect to anticipated use. Minor defects are related to minor problems with respect to anticipated use.

  • DEFECTIVE

A quality control term describing a unit of product or service containing at least one defect, or having several lesser imperfections that, in combination, cause the unit not to fulfill its anticipated function. NOTE: The term defective is not synonymous with nonconforming (or rejectable) and should be applied only to those units incapable of performing their anticipated functions.

  • DEFINED BENEFIT RETIREMENT PLAN

A type of pension plan whereby the employer promises to make pension payments to retired employees in specified amounts, regardless of the performance of the fi Because the employees' total years of service and their length of retirement are uncertain, the employer's future liabilities must be estimated and can fluctuate over time

  • DEFINED CONTRIBUTION RETIREMENT PLAN

A pension plan in which the employer promises to make specified contributions to the pension fund, but the amount of pension benefits ultimately paid to retired employees depends on how well the pension fund's assets are managed. There a no balance sheet items for Defined Contribution Plans because all liabilities are satisfied in full each year

  • DEFORMATION BANDS

Parts of a crystal that have rotated differently during deformation to produce bands of varied orientation within individual grains.

  • DEGASIFIER

A substance that can be added to molten metal to remove soluble gases that might otherwise be occluded or entrapped in the metal during solidification. Degassing

  • DEGREASING

Removing oil or grease from a surface. See solvent degreasing and vapor degreasing.

  • DEGREES OF FREEDOM

The number of independent variables (such as temperature, pressure or concentration within the phases present) that may be altered at will without causing a phase change in an alloy system at equilibrium; or the number of such variables that must be fixed arbitrarily to define the system completely.

  • DELAYED YIELD

A phenomenon involving a delay in time between the application of a stress and the occurrence of the corresponding yield point strain.

  • DELTA FERRITE

See ferrite

  • DENDRITE

A crystal that has a beelike branching pattern, being most evident in cast metals slowly cooled through the solidification range.

  • DENDRITIC POWDER

Particles of metal powder, usually of electrolytic origin, having typical pine-tree structure.

  • DENICKELIFICATION

Corrosion in which nickel is selectively leached from nickel-containing alloys. Most commonly observed in copper-nickel alloys after extended service in fresh water.

  • DENSITY RATIO

The ratio of the determined density of a powder metallurgy compact to the absolute density of metal of the same composition, usually expressed as a percentage.

  • DEOXIDIZED COPPER

Copper from which cuprous oxide has been removed by adding a deoxidizer, such as phosphorus, to the molten bath.

  • DEOXIDIZER

A substance that can be added to molten metal to remove either free or combined oxygen.

  • DEOXIDIZING

(1) The removal of oxygen from molten metals by use of suitable deoxidizers. (2) Sometimes refers to the removal of undesirable elements other than oxygen by the introduction of elements or compounds that readily react with them. (3) In metal finishing, the removal of oxide films from metal surfaces by chemical or electrochemical reaction.

  • DEPOLARIZATION

A decrease in the polarization of an electrode.

  • DEPOLARIZER

A substance that produces depolarization

  • DEPOSITION EFFICIENCY

In welding, the ratio of the weight of deposited weld metal to the net weight of electrodes consumed, exclusive of stubs.

  • DEPOSITION SEQUENCE

The order in which increments of weld metal are deposited.

  • DEPTH OF CUT

The thickness of material removed from a workpiece in a single machining pass.

  • DEPTH OF FUSION

In welding, the distance that fusion extends into the base metal or into a previous pass.

  • DEPTH OF PENETRATION

See joint penetration and root penetration.

  • DESCALING

Removing the thick layer of oxides formed on some metals at elevated temperatures.

  • DESEAMING

Analogous to chipping, the surface imperfections being removed by gas cutting.

  • DESULFURIZATION

WHAT. Operation that injects a chemical mixture into a ladle full of hot metal to remove sulfur prior to its charging into the Basic Oxygen Furnace. WHY. Sulfur enters the steel from the coke in the blast furnace smelting operation and there is little the steelmaker can do to reduce its presence. Because excess sulfur in the steel impedes its welding and forming characteristics, the mill must a this step to the steelmaking process

  • DETERGENT

A chemical substance, generally used in aqueous solution, that removes soil.

  • DETRITUS

Wear debris.

  • DEVELOPED BLANK

A blank that requires little or no trimming when formed.

  • DEZINCIFICATION

Corrosion in which zinc is selectively leached from zinccontaining alloys. Most commonly found in copper-zinc alloys containing less than 85percent copper after extended service in water containing dissolved oxygen.

  • DIAMAGNETIC MATERIAL

A material whose specific permeability is less than unity and is therefore repelled weakly by a magnet. Compare with ferromagnetic material, paramagnetic material.

  • DIAMOND BORING

Precision boring with a shaped diamond (but not with other tool materials). diamond pyramid hardness test

  • DIAMOND TOOL

(1) A diamond, shaped or formed to the contour of a single- pointed cutting tool, for use in the precision machining of nonferrous or nonmetallic materials. (2) Sometimes an insert made from multicrystalline diamond compacts.

  • DIAMOND WHEEL

A grinding wheel in which crushed and sized industrial diamonds are held in a resinoid, metal or vitrified bond.

  • DIAPHRAGM

(1) A porous or permeable membrane separating anode and cathode compartments of an electrolytic cell from each other or from an intermediate compartment. (2) Universal die member made of rubber or similar material used to contain hydraulic fluid within the forming cavity and transmit pressure to the part being formed.

  • DICHROMATE TREATMENT

A chromate conversion coating produced on magnesium alloys in a boiling solution of sodium dichromate.

  • DIDYMIUM

A natural mixture of the rare-earth elements praseodymium and neodymium, often given the quasichemical symbol Di.

  • DIE

A tool, usually containing a cavity, that imparts shape to solid, molten or powdered metal primarily because of the shape of the tool itself. Used in many press operations (including blanking, drawing, forging and forming), in die casting and in forming green powder metallurgy compacts. Die-casting and powder-metallurgy dies are sometimes referred to as molds.

  • DIE BLOCK

A block, usually of tool steel, into which the desired impressions are sunk, formed, or machined and from which forgings or die castings are made.

  • DIE BODY

The stationary or fixed part of a powder pressing die.

  • DIE CASTING

(1) A casting made in a die. (2) A casting process where molten metal is forced under high pressure into the cavity of a metal mold.

  • DIE CLEARANCE

Clearance between a mated punch and die; commonly expressed as clearance per side. Also called clearance, punch-to-die clearance.

  • DIE CUSHION

A press accessory located beneath or within a bolster or die block to provide an additional motion or pressure for stamping operations; actuated by air, oil, rubber or springs, or by a combination thereof.

  • DIE FORGING

A forging whose shape is determined by impressions in specially prepared dies.

  • DIE FORMING

The shaping of solid or powdered metal by forcing it into or through the cavity in a die.

  • DIE HOLDER

A plate or block, upon which the die block is mounted, having holes or slots for fastening to the bolster or the bed of the press.

  • DIE INSERT

A removable liner or part of a die body or punch.

  • DIE LAYOUT

The transfer of drawing or sketch dimensions to templates or die surfaces for use in sinking dies.

  • DIE LIFE

The productive life of a die impression, usually expressed as the number of units produced before the impression has worn beyond permitted tolerances.

  • DIE LINES

Lines or markings on formed, drawn or extruded metal parts caused by imperfections in the surface of the die.

  • DIE LUBRICANT

A lubricant applied to working surfaces of dies and punches to facilitate drawing, pressing, stamping and/or ejection. In powder metallurgy, the die lubricant is some- times mixed into the powder before pressing into a compact.

  • DIE MATCH

The condition where dies, after having been set up in a press or other equipment, are in proper alignment relative to each other.

  • DIE OPENING

In flash or upset welding, the distance between the electrodes, usually measured with the parts in contact before welding has commenced or immediately upon completion of the cycle but before upsetting.

  • DIE PROOF

A casting of the die impression made to confirm the exactness of the impression. Also called cast.

  • DIE RADIUS

The radius on the exposed edge of a drawing die, over which the sheet flows in forming drawn shells.

  • DIE SCALPING

Removing surface layers from bar, rod, wire or tube by drawing through a sharp-edged die to eliminate minor surface defects.

  • DIE SET

A tool or tool holder consisting of a die base and punch plate for the attachment of a die and punch, respectively.

  • DIE SHIFT

A condition requiring correction where, after dies have been set up in the forging equipment, displacement of a point in one die from the corresponding point in the opposite Die occurs in a direction parallel to the fundamental parting line of the dies.

  • DIE SINKING

Forming or machining a depressed pattern in a die.

  • DIE WELDING

Forge welding between dies.

  • DIFFERENCES

Electrogalvanizing equipment is more expensive to build and to operate than hot dipped, but it gives the steelmaker more precise control over the weight of the zinc coating. The automotive manufacturers, because they need superior welding, forming and painting ability of electrogalvanized steel, purchase 90percent of all tonnage produced

  • DIFFERENTIAL COATING

A coated product having a specified coating on one surface and a significantly lighter coating on the other surface (such as a hot dip galvanized product or electrolytic tin plate).

  • DIFFERENTIAL FLOTATION

Separating a complex ore into two or more valuable minerals and gangue by flotation. Also called selective flotation.

  • DIFFERENTIAL HEATING

Heating that intentionally produces a temperature gradient within an object such that, after cooling, a desired stress distribution or variation in properties is present within the object.

  • DIFFUSION

(1) Spreading of a constituent in a gas, liquid or solid, tending to make the composition of all parts uniform. (2) The spontaneous movement of atoms or molecules to new sites within a material.

  • DIFFUSION AID

A solid filler metal sometimes used in diffusion welding.

  • DIFFUSION BONDING

See preferred terms diffusion welding, diffusion brazing.

  • DIFFUSION BRAZING

A brazing process that joins two or more components by heating them to suitable temperatures and by using a filler metal or an in situ liquid phase. The filler metal may be distributed by capillary attraction or may be placed or formed at the faying surfaces. The filler metal is diffused with the base metal to the extent that the joint properties have been changed to approach those of the base metal.

  • DIFFUSION COATING

Any process whereby a basis metal or alloy is either: (1) coated with another metal or alloy and heated to a sufficient temperature in a suitable environment or (2) exposed to a gaseous or liquid medium containing the other metal or alloy, thus causing diffusion of the coating or of the other metal or alloy into the basis metal with resultant change in the composition and properties of its surface.

  • DIFFUSION COEFFICIENT

A factor of proportionality representing the amount of substance diffusing across a unit area through a unit concentration gradient in unit time.

  • DIFFUSION WELDING

A high-temperature solid state welding process that permanently joins faying surfaces by the simultaneous application of pressure and heat. The process does not involve macroscopic deformation, melting, or relative motion of parts. A solid filler metal (diffusion aid) may or may not be inserted between the faying surfaces.

  • DILATOMETER

An instrument for measuring the linear expansion or contraction in a metal resulting from changes in such factors as temperature or allotropy.

  • DIMPLE RUPTURE

A fractographic term describing ductile fracture that occurred through the formation and coalescence of microvoids along the fracture path. The fracture surface of such a ductile fracture appears dimpled when observed at high magnification and usually is most clearly resolved when viewed in a scanning electron microscope.

  • DIMPLING

(1) Stretching a relatively small shallow indentation into sheet metal. (2) In aircraft, stretching thin metal into a conical flange for use with a countersunk head rivet.

  • DIP BRAZING

Brazing by immersing the assembly to be joined in a bath of hot molten chemicals or hot metal. A molten chemical bath may provide brazing flux; molten metal, the filler metal.

  • DIP PLATING

Same as immersion plating.

  • DIPHASE CLEANING

Removing soil by an emulsion that produces two phases in the cleaning tank: a solvent phase and an aqueous phase. Cleaning is effected by both solvent action emulsification.

  • DIRECT CHILL CASTING

A continuous method of making ingots for rolling or extrusion by pouring the metal into a short mold. The base of the mold is a platform that is gradually lowered while the metal solidifies, the frozen shell of metal acting as a retainer for the liquid metal below the wall of the mold. The ingot is usually cooled by the impingement of water directly on the mold or on the walls of the solid metal as it is lowered. The length of the ingot is limited by the depth to which the platform can be lowered; therefore, it is often called semicontinuous casting.

  • DIRECT EXTRUSION

See extrusion.

  • DIRECT QUENCHING

(1) Quenching carburized parts directly from the carburizing operation. (2) Also used for quenching pearlitic malleable parts directly from the malleablizing operation.

  • DIRECT REDUCED IRON (DRI)

WHAT. Processed iron ore that is iron-rich enough to be used as a scrap substitute electric furnace steelmaking. WHY. As mini-mills expand their product abilities to sheet steel, they require much higher grades of crap to approach integrated mill quality. Enabling the mini-mills to use iron ore without the blast furnace, DRI can serve as a low residual raw material and alleviate the mini-mills' dependence on cleaner, higher-priced scrap. HOW. The impurities in the crushed iron ore are driven off through the use of massive amounts of natural gas. While the result is 97percent pure iron (compared with blast furnace hot metal, which, because it is saturated with carbon, is only 93percent iron), DRI is only economically feasible in regions where natural gas is attractively priced

  • DIRECT-ARC FURNACE

An electric-arc furnace in which the metallic charge is one of the poles of the arc.

  • DIRECT-CURRENT CLEANING

Same as cathodic cleaning.

  • DIRECTIONAL PROPERTY

Property whose magnitude varies depending on the relation of the test axis to a specific direction within the metal. The variation results from preferred orientation or from fibering of constituents or inclusions.

  • DIRECTIONAL SOLIDIFICATION

The solidification of molten metal in such a manner that feed metal is always available for that portion that is just solidifying.

  • DISCONTINUOUS YIELDING

The nonuniform plastic flow of a metal exhibiting a yield point in which plastic deformation is inhomogeneously distributed along the gage length. Under some circumstances, it may occur in metals not exhibiting a distinct yield point, either at the onset of or during plastic flow.

  • DISHING

Forming a shallow concave surface, the area being large compared to the depth.

  • DISK GRINDING

Grinding with the flat side of an abrasive disk or segmented wheel.

  • DISLOCATION

A linear imperfection in a crystalline array of atoms. Two basic types are recognized: an edge dislocation corresponds to the row of mismatched atoms along the edge formed by an extra, partial plane of atoms within the body of a crystal; a screw dislocation corresponds to the axis of a spiral structure in a crystal, characterized by a distortion that joins normally parallel planes together to form a continuous helical ramp (with a pitch of one interplanar distance) winding about the dislocation. Most prevalent is the so-called mixed dislocation, which is the name given to any combination of an edge dislocation and a screw dislocation.

  • DISORDERING

Forming a lattice arrangement in which the solute and solvent atoms of a solid solution occupy lattice sites at random. See also ordering, superlattice.

  • DISPERSING AGENT

A material that increases the stability of a suspension of particles in a liquid medium by deflocculation of the primary particles.

  • DISRUPTIVE STRENGTH

The stress at which a metal fractures under hydrostatic tension.

  • DISTORTION

Any deviation from an original size, shape or contour that occurs because of the application of stress or the release of residual stress.

  • DISTURBED METAL

The cold worked metal layer formed at a polished surface during the process of mechanical grinding and polishing.

  • DIVIDED CELL

A cell containing a diaphragm or other means for physically separating the anolyte from the catholyte.

  • DIVORCED EUTECTIC

A metallographic appearance in which the two constituents of a eutectic structure appear as massive phases rather than the finely divided mixture characteristic of normal eutectics. Often, one of the constituents of the eutectic is continuous with and indistinguishable from an accompanying proeutectic constituent.

  • DOMAIN

A substructure in a ferromagnetic material within which all the elementary magnets (electron spins), are held aligned in one direction by interatomic forces; if isolated, a domain would be a saturated permanent magnet.

  • DOR� SILVER

Crude silver containing a small amount of gold, obtained after removing lead in a cupelling furnace Same as dor� bullion and dor� metal.

  • DOUBLE AGING

Employment of two different aging treatments to control the type of precipitate formed from a supersaturated matrix in order to obtain the desired properties. The first aging treatment, sometimes referred to as intermediate or stabilizing, is usually carried out at higher temperature than the second.

  • DOUBLE SALT

A compound of two salts that crystallize together in a definite proportion.

  • DOUBLE TEMPERING

A treatment in which a quench-hardened ferrous metal is subjected to two complete tempering cycles, usually at substantially the same temperature, for the purpose of ensuring completion of the tempering reaction and promoting stability of the resulting microstructure.

  • DOUBLE-ACTING HAMMER

A forging hammer in which the ram is raised by admitting steam or air into a cylinder below the piston, and the blow intensified by admitting steam or air above the piston on the downward stroke.

  • DOUBLE-ACTION DIE

A die designed to perform more than one operation in a single stroke of the press.

  • DOUBLE-ACTION FORMING

Forming or drawing where more than one action is achieved in a single stroke of the press.

  • DOUBLE-ACTION MECHANICAL PRESS

A press having two independent parallel movements by means of two slides, one moving within the other. The inner slide or plunger is usually operated by a crankshaft, whereas the outer or blankholder slide, which dwells during the drawing operation, is usually operated by a toggle mechanism or cams.

  • DOUBLE-BEVEL GROOVE WELD

A groove weld in which the joint edge of one member is beveled from both sides.

  • DOUBLE-J GROOVE WELD

A groove weld in which the joint edge of one member is in the form of two J's, one from either side.

  • DOUBLE-U GROOVE WELD

A groove weld in which each joint edge is in the form of two J's or two half-U's, one from either side of the member.

  • DOUBLE-V GROOVE WELD

A groove weld in which each joint edge is beveled from both sides.

  • DOUBLE-WELDED JOINT

A butt, edge, tee, corner or lap joint in which welding has been done from both sides.

  • DOW PROCESS

A process for the production of magnesium by electrolysis of molten magnesium chloride.

  • DOWNGATE

Same as sprue.

  • DOWNHAND WELDING

See flat-position welding.

  • DOWNSPRUE

Same as sprue.

  • DRAFT

(1) An angle or taper on the surface of a pattern, core box, punch or die (or of the parts made with them) that makes it easier to remove the parts from a mold or die cavity, or to remove a core from a casting. (2) The change in cross section that occurs during rolling or cold

  • DRAG ANGLE

In welding, the angle between the axis of the electrode or torch and a line normal to the plane of the weld when welding is being done with the torch positioned ahead of the weld puddle. See sketch accompanying backhand welding.

  • DRAG TECHNIQUE

A method used in manual arc welding where the electrode is in contact with the assembly being welded without being in short circuit. The electrode is usually used without oscillation.

  • DRAG-IN

Water or solution carried into another solution by the work and its associated handling equipment.

  • DRAGOUT

Solution carried out of a bath by the work and its associated handling equipment.

  • DRAW BEAD

(1) A bead or offset used for controlling metal flow. (2) Riblike projections on draw rings or holddown surfaces for controlling metal flow.

  • DRAW FORGING

See radial forging.

  • DRAW FORMING

A method of curving bars, tubes or rolled or extruded sections, in which the stock is bent around a rotating form block. Stock is bent by clamping it to the form block, then rotating the form block while the stock is pressed between the form block and a pressure die held against the periphery of the form block.

  • DRAW HEAD

Set of rolls or dies mounted on a drawbench for forming a section from strip, tubing or solid stock.

  • DRAW MARKS

See scoring, galling, pick- up, die lines.

  • DRAW PLATE

A circular plate with a hole in the center contoured to fit a forming punch, used to support the blank during the forming cycle.

  • DRAW RADIUS

The radius at the edge of a die or punch over which the work is drawn.

  • DRAW RING

A ring-shaped die part over the inner edge of which the metal is drawn by the punch.

  • DRAWABILITY

A measure of the workability of a metal subject to a drawing process. A term usually expressed to indicate a metal's ability to be deep drawn.

  • DRAWBENCH

The stand that holds the die and draw head used in the drawing of wire, rod and tubing.

  • DRAWING

(1) Forming recessed parts by forcing the plastic flow of metal in dies. (2) Reducing the cross section of bar stock, wire or tubing by pulling it through a die. (3) A misnomer for tempering.

  • DRAWING COMPOUND

A substance applied to prevent pickup and scoring during drawing or pressing operations by preventing metal-to-metal contact of the work and die. Also known as die lubricant.

  • DRAWING OUT

A stretching operation resulting from forging a series of up- sets along the length of the workpiece.

  • DRAWN SHELL

An article formed by drawing sheet metal into a hollow structure having a predetermined geometrical configuration.

  • DRAWN-OVER MANDREL

A procedure for producing specialty tubing using a drawbench to pull tubing through a die and over a mandrel, giving excellent control over the inside diameter and wall thickness. Advantages of this technique are its inside and outside surface quality and gauge tolerance. Major markets include automotive applications and hydraulic cylinders

  • DRESSER

A tool used for truing and dressing a grinding wheel.

  • DRESSING

Cutting, breaking down or crushing the surface of a grinding wheel to improve its cutting ability and accuracy.

  • DRIFT

(1) A flat piece of steel of tapering width used to remove taper shank drills and other tools from their holders. (2) A tapered rod used to force mismated holes in line for riveting or bolting. Sometimes called a drift pin.

  • DRILL

A rotary end-cutting tool used for making holes; it has one or more cutting lips and an equal number of helical or straight flutes for the passage of chips and the admission of a cutting fluid.

  • DRILL PIPE

Pipe used in the drilling of an oil or gas well. Drill pipe is the conduit between the wellhead motor and the drill bit. Drilling mud is pumped down the center of the pipe during drilling, to lubricate the drill bit and transmit the drilled core to the surface. Because of the high stress, torque and temperature associated with well drilling, drill pipe is a seamless product

  • DRIVE FIT

A type of force fit.

  • DROP

A casting imperfection due to a portion of the sand dropping from the cope or other overhanging section of the mold.

  • DROP FORGING

A shallow forging made in impression dies; usually with a drop hammer.

  • DROP HAMMER

A forging hammer that depends on gravity for its force.

  • DROSS

The scum that forms on the surface of molten metals largely because of oxidation but sometimes because of the rising of impurities to the surface.

  • DRY CYANIDING

(obsolete) Same as carbonitriding

  • DRY SAND MOLD

A casting mold made of sand and then dried at 100�C (212�F) or above before using. Contrast with green sand mold.

  • DUCTILE CAST IRON

A cast iron that has been treated while molten with an element such as magnesium or cerium to induce the formation of free graphite as nodules or spherulites, which imparts a measurable degree of ductility to the cast metal. Also known as nodular cast iron, spherulitic graphite cast iron and SG iron.

  • DUCTILE CRACK PROPAGATION

Slow crack propagation that is accompanied by noticeable plastic deformation and requires energy to be supplied from outside the body.

  • DUCTILE FRACTURE

Fracture characterized by tearing of metal accompanied by appreciable gross plastic deformation and expenditure of considerable energy.

  • DUCTILITY

The ability of a material to deform plastically without fracturing, being measured by elongation or reduction of area in a tensile test, by height of cupping in an Erichsen test or by other means.

  • DUCTILITY

Ability of steel to undergo permanent changes in shape without fracture at room temperature

  • DUMMY BLOCK

In extrusion, a thick unattached disk placed between the ram and billet to prevent overheating of the ram.

  • DUMPING

Dumping occurs when imported merchandise is sold in, or for export to the domestic market at less than the normal value of the merchandise-that is, at a price that is less than the price at which identical or similar merchandise is sold in the comparison market, the home market (the market of the exporting country), or third country market (in this case, "market" is used as proxy for "home market" in cases where home market cannot be used). The normal value of the merchandise cannot be below the cost of production

  • DUMPING MARGIN

The amount by which the normal value exceeds the export price or constructed export price of the subject merchandise

  • DUPLEX

A category of stainless steel with high amounts of chromium and moderate nickel content. The duplex class is so named because it is a mixture of austenitic (chromium-nickel stainless class) and ferritic (plain chromium stainless category) structures. This combination was originated to offer more strength than either of those stainless steels. Duplex stainless steels provide high resistance to stress corrosion cracking (formation of cracks caused by a combination of corrosion and stress) and are suitable for heat exchangers, desalination plants, and marine applications

  • DUPLEX COATING

See composite plate.

  • DUPLEXING

Any two-furnace melting or refining process. Also called duplex melting or duplex processing.

  • DUPLICATING

In machining and grinding, reproducing a form from a master with an appropriate type of machine tool, utilizing a suitable tracer or program-controlled mechanism.

  • DURALUMIN

(obsolete) A term formerly applied to the class of age-hardenable aluminum-copper alloys containing manganese, magnesium or silicon.

  • DURVILLE PROCESS

A casting process that involves rigid attachment of the mold in an inverted position above the crucible. The melt is poured by tilting the entire assembly, causing the metal to flow along a connecting launder and down the side of the mold.

  • DUSTING

Applying a powder; as sulfur to molten magnesium, or graphite to a mold surface.

  • DUTY CYCLE

For electric welding equipment, the percentage of time that current flows during a specified period. In arc welding, the specified period is 10 min.

  • DYNAMIC CREEP

Creep that occurs under conditions of fluctuating load or fluctuating temperature.

  • EARING

The formation of scallops (ears) around the top edge of a drawn part caused by directional differences in the properties of the sheet metal used.

  • ECCENTRIC PRESS

A mechanical press in which the eccentric and strap are used to move the slide, rather than a crankshaft and connection.

  • ECM

An abbreviation for electrochemical machining.

  • EDDY-CURRENT TESTING

An electromagnetic nondestructive testing method in which eddy-current flow is induced in the test object. Changes in the flow caused by variations in the object are reflected into a nearby coil or coils where they are detected and measured by suitable instrumentation.

  • EDGE DISLOCATION

See dislocation.

  • EDGE JOINT

A joint between the edges of two or more parallel or nearly parallel members.

  • EDGE ROLLING (EDGE CONDITIONING)

Rolling a strip of steel to smooth the edges. By removing the burr off the coi safer for customers to manipulate

  • EDGE STRAIN

Transverse strain lines or L�ders lines ranging from 25 to 300 mm (1 to 12 in.) in from the edges of cold rolled steel sheet or strip.

  • EDGER

In forging, the portion of a die that generally distributes the metal in portions required for the shape to be forged, usually a gathering operation. A rolling edger shapes the stock into various solids of revolution; a ball edger forms a ball.

  • EDGING

(1) In forming, reducing the flange radius by retracting the forming punch a small amount after the stroke but prior to releasing the pressure. (2) In forging, removing flash that is directed upward between dies, usually accomplished in a lathe. (3) In rolling, working metal where the axis of the roll is parallel to the thickness dimension. Also called edge rolling.

  • EDM

An abbreviation for electrical discharge machining.

  • EFFECTIVE RAKE

The angle between a plane containing a tooth face and the axial plane through the tooth point as measured in the direction of chip flow through the tooth point. Thus, it is the rake resulting from both cutter configuration and direction of chip flow.

  • EJECTOR

A device mounted in such a way that it removes or assists in removing a formed part from a die.

  • EJECTOR HALF

The movable half of a diecasting die containing the ejector pins.

  • ELASTIC AFTEREFFECT

Time-dependent recovery, toward original dimensions, after the load has been reduced or removed from an elastically or plastically strained body. See anelasticity.

  • ELASTIC CONSTANTS

Factors of proportionality that describe elastic response of a material to applied forces; includes modulus of elasticity (either in tension, compression or shear), Poisson's ratio, compressibility and bulk modulus.

  • ELASTIC DEFORMATION

A change in dimensions directly proportional to and in phase with an increase or decrease in applied force.

  • ELASTIC HYSTERESIS

A misnomer for an anelastic strain that lags a change in applied stress, thereby creating energy loss during cyclic loading. More properly termed mechanical hysteresis.

  • ELASTIC LIMIT

The maximum stress to which a material may be subjected without any permanent strain remaining upon complete release of stress.

  • ELASTIC MODULUS

Same as modulus of elasticity.

  • ELASTIC RATIO

Yield point divided by tensile strength.

  • ELASTIC STRAIN

Same as elastic deformation.

  • ELASTIC WAVES

Mechanical vibrations in an elastic medium.

  • ELASTICITY

Ability of a solid to deform in direct proportion to and in phase with increases or decreases in applied force.

  • ELECTRIC ARC FURNACE (EAF)

Steelmaking furnace where scrap is generally 100percent of the charge. Heat is supplied from electricity that arcs from the graphite electrodes to the metal bath. Furnaces may be either an alternating current (AC) or direct current (DC). DC units consume less energy and fewer electrodes, but they are more expensive

  • ELECTRIC RESISTANCE WELDED (ERW) PIPE

Pipe made from strips of hot-rolled steel which are passed through forming rolls and welded. While seamless pipe is traditionally stronger and more expensive the comparable ERW pipe, ERW technology is improving and the technique now accounts for approximately 48percent of OCTG shipments by tonnage

  • ELECTRICAL DISCHARGE MACHINING

Removal of stock from an electrically conductive material by rapid, repetitive spark discharge through a dielectric fluid flowing between the work- piece and a shaped electrode. Often abbreviated EDM. Variations of the process include electrical discharge grinding and electrical discharge wire cutting.

  • ELECTRICAL DISINTEGRATION

Metal removal by an electrical spark acting in air. It is not subject to precise control, the most common application being the removal of broken tools such as taps and drills; hence the shop name "tap buster".

  • ELECTRICAL STEEL

(See Silicon Electrical Steel)

  • ELECTROCHEMICAL CORROSION

Corrosion that is accompanied by a flow of electrons between cathodic and anodic areas on metallic surfaces.

  • ELECTROCHEMICAL EQUIVALENT

The weight of an element, compound, radical, or ion involved in a specified electrochemical reaction during the passage of a unit quantity of electricity.

  • ELECTROCHEMICAL MACHINING

Removal of stock from an electrically conductive material by anodic dissolution in an electrolyte flowing rapidly through a gap between the workpiece and a shaped electrode. Often abbreviated ECM. Variations of the process include electrochemical deburring and electrochemical grinding.

  • ELECTROCHEMICAL SERIES

Same as electromotive series.

  • ELECTRODE

(1) In arc welding, a current-carrying rod that supports the arc between the rod and work, or between two rods as in twin carbon-arc welding. It may or may not furnish filler metal. See bare electrode, covered electrode and lightly coated electrode. (2) In resistance welding, a part of a resistance welding machine through which current and, in most instances, pressure are applied directly to the work. The electrode may be in the form of a rotating wheel, rotating roll, bar, cylinder, plate, clamp, chuck or modification thereof. (3) An electrical conductor for leading current into or out of a medium.

  • ELECTRODE CABLE

Same as electrode lead.

  • ELECTRODE DEPOSITION

The weight of weld metal deposit obtained from a unit length of electrode.

  • ELECTRODE FORCE

The force between electrodes in spot, seam and projection welding.

  • ELECTRODE LEAD

The electrical conductor between the source of arc welding current and the electrode holder.

  • ELECTRODE POTENTIAL

The potential of a halfcell as measured against a standard reference half cell.

  • ELECTRODE SKID

In spot, seam or projection welding, the sliding of an electrode along the surface of the work.

  • ELECTRODEPOSITION

The deposition of a substance upon an electrode by passing electric current through an electrolyte. Electroplating (plating), electroforming, electrorefining and Electrowinning result from electrodeposition.

  • ELECTROFORMING

Making parts by electrodeposition on a removable form.

  • ELECTROGALVANIZED

Zinc plating process whereby the molecules on the positively charged zinc anode attach to the negatively charged sheet steel. The thickness zinc coating is readily controlled. By increasing the electric charge or slowing speed of the steel through the plating area, the coating will thicken

  • ELECTROGALVANIZING

The electroplating of zinc upon iron or steel.

  • ELECTROGAS WELDING

A process for vertical position welding in which molding shoes confine the molten weld metal. Welding may be done by either gas metal arc welding or flux cored arc welding.

  • ELECTROLESS PLATING

A process in which metal ions in a dilute aqueous solution are plated out on a substrate by means of autocatalytic chemical reaction.

  • ELECTROLYSIS

Chemical change resulting from the passage of an electric current through an electrolyte.

  • ELECTROLYTE

(1) An ionic conductor. (2) A liquid, most often a solution, that will conduct an electric current.

  • ELECTROLYTIC BRIGHTENING

Same as electropolishing.

  • ELECTROLYTIC CELL

An assembly, consisting of a vessel, electrodes and an electrolyte, in which electrolysis can be carried out.

  • ELECTROLYTIC CLEANING

Removing soil from work by electrolysis, the work being one of the electrodes. The electrolyte is usually alkaline.

  • ELECTROLYTIC COPPER

Copper that has been refined by electrolytic deposition, including cathodes that are the direct product of the refining operation, refinery shapes cast from melted cathodes, and, by extension, fabricators' products made therefrom. Usually when this term is used alone, it refers to electrolytic tough pitch copper without elements other than oxygen being present in significant amounts.

  • ELECTROLYTIC DEPOSITION

Same as electrodeposition.

  • ELECTROLYTIC GRINDING

A combination of grinding and machining where a metal-bonded abrasive wheel, usually diamond, is the cathode in physical contact with the anodic workpiece, the contact being made underneath the surface of a suitable electrolyte. The abrasive particles produce grinding and act as nonconducting spacers permitting simultaneous machining through electrolysis.

  • ELECTROLYTIC MACHINING

Controlled removal of metal by an applied potential and suitable electrolyte to produce the shapes and dimensions desired.

  • ELECTROLYTIC PICKLING

Pickling where electric current is used, the work being one of the electrodes.

  • ELECTROLYTIC POWDER

Metal powder produced by electrolytic deposition or by the pulverization of an electrodeposit, or from metal made by electrodeposition.

  • ELECTROLYTIC PROTECTION

See the preferred term, cathodic protection.

  • ELECTROMETALLURGY

Industrial recovery or processing of metals and alloys by electric or electrolytic methods.

  • ELECTROMOTIVE FORCE

Electrical potential; voltage.

  • ELECTROMOTIVE SERIES

A list of elements arranged according to their standard electrode potentials. In corrosion studies, the analogous but more practical galvanic series of metals is generally used. The relative position of a given metal is not necessarily the same in the two series.

  • ELECTRON BANDS

Energy states for the free electrons in a metal, as described using the band theory (zone theory) of electron structure. Also called Brillouin zones.

  • ELECTRON BEAM CUTTING

A cutting process that uses the heat obtained from a concentrated beam composed primarily of high-velocity electrons, which impinge upon the workpieces to be cut; it may or may not use an externally supplied gas.

  • ELECTRON BEAM MACHINING

Removing material by melting and vaporizing the workpiece at the point of impingement of a focused high velocity beam of electrons. The machining is done in high vacuum to eliminate scattering of the electrons due to interaction with gas molecules.

  • ELECTRON BEAM MICROPROBE ANALYZER

An instrument for selective analysis of a microscopic component or feature in which an electron beam bombards the point of interest in a vacuum at a given energy level. Scanning of a larger area permits determination of the distribution of selected elements. The analysis is made by measuring the wavelengths and intensities of secondary electromagnetic radiation resulting from the bombardment.

  • ELECTRON BEAM WELDING

A welding process that produces coalescence of metals with the heat obtained from a concentrated beam composed primarily of high-velocity electrons impinging upon the surfaces to be joined.

  • ELECTRON COMPOUND

An intermediate phase on a constitution diagram, usually a binary phase, that has the same crystal structure and the same ratio of valence electrons to atoms as intermediate phases in several other systems. An electron compound is often a solid solution of variable composition and good metallic properties. Occasionally, an ordered arrangement of atoms is characteristic of the compound, in which case the range of composition is usually small. Phase stability depends essentially on electron concentration and crystal structure and has been observed at valence-electron-to-atom ratios of 3/2, 21/13, and 7/4.

  • ELECTROPHORESIS

The transport of charged colloidal or macromolecular materials in an electric field.

  • ELECTROPLATING

Electrodepositing a metal or alloy in an adherent form on an object serving as a cathode.

  • ELECTROPOLISHING

(1) A technique commonly used to prepare metallographic specimens, in which a high polish is produced by making the specimen the anode in an electrolytic cell, where preferential dissolution at high points smooths the surface. (2) A variation of chemical machining wherein electrolytic depleting promotes chemical cutting, especially at surface irregularities.

  • ELECTROREFINING

Using electric or electrolytic methods to convert impure metal to purer metal, or to produce an alloy from impure or partly purified raw materials.

  • ELECTROSLAG REMELTING

A consumable electrode remelting process in which heat is generated by the passage of electric current through a conductive slag. The droplets of metal are refined by contact with the slag. Sometimes abbreviated ESR.

  • ELECTROSLAG WELDING

A fusion welding process in which the welding heat is provided by passing an electric current through a layer of molten conductive slag contained in a pocket formed by molding shoes that bridge the gap between the members being welded. The resistance heated slag not only melts filler metal electrodes as they are fed into the slag layer, but also provides shielding for the massive weld puddle characteristic of the process.

  • ELECTROSTRICTIVE EFFECT

The reversible interaction, exhibited by some crystalline materials, between an elastic strain and an electric field. The direction of the strain is independent of the polarity of the field. Compare with piezoelectric effect.

  • ELECTROTINNING

Electroplating tin on an object.

  • ELECTROTYPING

The production of printing plates by electroforming.

  • ELECTROWINNING

Recovery of a metal from an ore by means of electrochemical processes.

  • ELONGATION

In tensile testing, the increase in the gage length, measured after fracture of the specimen within the gage length, usually expressed as a percentage of the original gage length.

  • ELUTRIATION

Separation of metal powder into particle-size fractions by means of a rising stream of gas or liquid.

  • EMBOSSING

Raising a design in relief against a surface.

  • EMBOSSING DIE

A die used for producing embossed designs.

  • EMBRITTLEMENT

Reduction in the normal ductility of a metal due to a physical or chemical change. Examples include blue brittleness, hydrogen embrittlement and temper brittleness.

  • EMERY

An impure mineral of the corundum or aluminum oxide type used extensively as an abrasive before the development of electric-furnace products.

  • EMF

An abbreviation for electromotive force.

  • EMISSIVITY

Ratio of the amount of energy or of energetic particles radiated from a unit area of a surface to the amount radiated from a unit area of an ideal emitter under the same conditions.

  • EMPTY

EMPTY

  • EMPTY

EMPTY

  • EMPTY

EMPTY

  • EMULSION

A dispersion of one liquid phase in another.

  • EMULSION CLEANER

A cleaner consisting of organic solvents dispersed in an aqueous medium with the aid of an emulsifying agent.

  • ENANTIOTROPY

The relation of crystal forms of the same substance in which one form is stable above a certain temperature and the other form stable below that temperature. Ferrite and austenite are enantiotropic in ferrous alloys, for example.

  • END CLEARANCE ANGLE

See clearance angle, and also sketches accompanying face mill and single-point tool.

  • END CUTTING EDGE ANGLE

The angle of concavity between the face cutting edge and the face plane of the cutter. It serves as relief to prevent the face cutting edges from rubbing in the cut. See sketches accompanying face mill and single-point tool.

  • END MARK

A roll mark caused by the end of a sheet marking the roll during hot or cold rolling.

  • END MILLING

A method of machining with a rotating peripheral and end cutting tool. See also face milling.

  • END-QUENCH HARDENABILITY TEST

A laboratory procedure for determining the hardenability of a steel or other ferrous alloy; widely referred to as the Jominy test. Hardenability is determined by heating a standard specimen above the upper critical temperature, placing the hot specimen in a fixture so that a stream of cold water impinges on one end, and, after cooling to room temperature is completed, measuring the hardness near the surface of the specimen at regularly spaced intervals along its length. The data are normally plotted as hardness versus distance from the quenched end.

  • ENDURANCE LIMIT

The maximum stress below which a material can presumably endure an infinite number of stress cycles. If the stress is not completely reversed, the value of the mean stress, the minimum stress or the stress ratio also should be stated. Compare with fatigue limit.

  • ENDURANCE RATIO

The ratio of the endurance limit for completely reversed flexural stress to the tensile strength of a given material.

  • ENGINEERED CAPACITY

The theoretical volume of a mill, given its constraints of raw material supply and normal working speed

  • ENTRY MARK (EXIT MARK)

A slight corrugation caused by the entry or exit rolls of a roller leveling unit.

  • EPITAXY

Growth of an electrodeposit or vapor deposit in which the orientations of the crystals in the deposit are directly related to crystal orientations in the underlying crystalline substrate.

  • EPSILON STRUCTURE

A Hume-Rothery designation for structurally analogous close-packed phases or electron compounds like CuZn3 that have ratios of seven valence electrons to four atoms. Not to be confused with the epsilon phase on a constitution diagram.

  • EQUIAXED GRAIN STRUCTURE

A structure in which the grains have approximately the same dimensions in all directions.

  • EQUILIBRIUM

A dynamic condition of physical, chemical, mechanical or atomic balance, where the condition appears to be one of rest rather than change.

  • EQUILIBRIUM DIAGRAM

A graphical representation of the temperature, pressure and composition limits of phase fields in an alloy system as they exist under conditions of complete equilibrium. In metal systems, pressure is usually considered constant.

  • ERICHSEN TEST

A cupping test in which a piece of sheet metal, restrained except at the center, is deformed by a cone-shaped spherical-end plunger until fracture occurs. The height of the cup in millimetres at fracture is a measure of the ductility.

  • EROSION

Destruction of metals or other materials by the abrasive action of moving fluids, usually accelerated by the presence of solid particles or matter in suspension. When corrosion occurs simultaneously, the term erosion-corrosion is often used.

  • EROSION-CORROSION

See erosion.

  • ETCH CLEANING

Removing soil by dissolving away some of the underlying metal.

  • ETCH CRACKS

Shallow cracks in hardened steel containing high residual surface stresses, produced on etching in an embrittling acid.

  • ETCH FIGURES

Characteristic markings produced on crystal surfaces by chemical attack, usually having facets that are parallel to low-index crystallographic planes.

  • ETCHANT

A chemical substance or mixture used for etching.

  • ETCHING

(1) Subjecting the surface of a metal to preferential chemical or electrolytic attack in order to reveal structural details for metallographic examination. (2) Chemically or electrochemically removing tenacious films from a metal surface to condition the surface for a subsequent treatment, such as painting or electroplating.

  • EUTECTIC

(1) An isothermal reversible reaction in which a liquid solution is converted into two or more intimately mixed solids on cooling, the number of solids formed being the same as the number of components in the system. (2) An alloy having the composition indicated by the eutectic point on an equilibrium diagram. (3) An alloy structure of intermixed solid constituents formed by a eutectic reaction.

  • EUTECTIC CARBIDE

Carbide formed during freezing as one of the mutually insoluble phases participating in the eutectic reaction of ferrous alloys.

  • EUTECTIC MELTING

Melting of localized microscopic areas whose composition corresponds to that of the eutectic in the system.

  • EUTECTOID

(1) An isothermal reversible reaction in which a solid solution is converted into two or more intimately mixed solids on cooling, the number of solids formed being the same as the number of components in the system. (2) An alloy having the composition indicated by the eutectoid point on an equilibrium diagram. (3) An alloy structure of intermixed solid constituents formed by a eutectoid reaction.

  • EXFOLIATION

A type of corrosion that progresses approximately parallel to the outer surface of the metal, causing layers of the metal to be elevated by the formation of corrosion product.

  • EXPANSION FIT

An interference or force fit made by placing a cold (subzero) inside member into a warmer outside member and allowing an equalization of temperature.

  • EXPLOSION WELDING

A solid state welding process effected by a controlled detonation, which causes the parts to move together at high velocity.

  • EXPLOSIVE FORMING

Shaping metal parts where the forming pressure is generated by an explosive charge.

  • EXTENSOMETER

An instrument for measuring changes in length caused by application or removal of a force. Commonly used in tension testing of metal specimens.

  • EXTRA HARD

A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about one-third of the way from full hard to extra spring temper.

  • EXTRA SPRING

A temper of nonferrous alloys and some ferrous alloys corresponding approximately to a cold worked state above full hard beyond which further cold work will not measurably increase the strength and hardness.

  • EXTRACTIVE METALLURGY

The branch of process metallurgy dealing with the winning of metals from their ores. Compare with refining.

  • EXTRUDED HOLE

A hole formed by a punch that first cleanly cuts a hole and then is pushed farther through to form a flange with an enlargement of the original hole.

  • EXTRUSION

Conversion of an ingot or billet into lengths of uniform cross section by forcing metal to flow plastically through a die orifice. In direct extrusion (forward extrusion), the die and ram are at opposite ends of the extrusion stock, and the product and ram travel in the same direction. Also, there is relative motion between the extrusion stock and the container. In- indirect extrusion (backward extrusion), the die is at the ram end of the stock and the product travels in the opposite direction as the ram, either around the ram (as in the impact extrusion of cylinders such as cases for dry cell batteries) or up through the center of a hollow ram. Impact extrusion is the process (or resultant product) in which a punch strikes a slug (usually unheated) in a confining die. The metal flow may be either between punch and die or through another opening. Impact extrusion of unheated slugs is often called cold extrusion. See also Hooker process, which uses a pierced slug. A stepped extrusion is a single product having one or more abrupt changes in cross section. It is produced by stopping extrusion to change dies. Often, such an extrusion is made in a complex die having a die section that can be freed from the main die and allowed to ride out with the product when extrusion is resumed.

  • EXTRUSION BILLET

A metal slug used as extrusion stock.

  • EXTRUSION DEFECT

See preferred term, extrusion pipe

  • EXTRUSION INGOT

A cast metal slug used as extrusion stock

  • EXTRUSION PIPE

A central oxide-lined discontinuity that occasionally occurs in the last 10 to 20percent of an extruded bar. It is caused by the oxidized outer surface of the billet flowing around the end of the billet and into the center of the bar during the final stages of extrusion. Also called coring.

  • EXTRUSION STOCK

A rod, bar or other section used to make extrusions.

  • EYELETING

Displacing material about an opening in sheet or plate so that a lip protruding above the surface is formed.

  • FABRICATOR

A producer of intermediate products that does not also produce primary metal. For example, a rebar (see Reinforcing Bar) fabricator purchases rebar and processes material to the specifications of a particular construction project

  • FACE

In a lathe tool, the surface against which the chips bear as they are formed. See sketch accompanying single-point tool.

  • FACE MILL

See definition of nomenclature in accompanying sketch.

  • FACE MILLING

Milling a surface that is perpendicular to the cutter axis.

  • FACE OF WELD

The exposed surface of an arc or gas weld on the side from which the welding was done. See sketch accompanying fillet weld.

  • FACE-TYPE CUTTERS

Cutters that can be mounted directly on and driven from the machine spindle nose.

  • FACING

(1) In machining, generating a surface on a rotating workpiece by the traverse of a tool perpendicular to the axis of rotation. (2) In founding, special sand placed against a pattern to improve the surface quality of the casting. (3) For abrasion resistance, see preferred term hard facing.

  • FAGOT

In forging work, a bundle of iron bars that will be heated and then hammered and welded to form a single bar.

  • FAILURE

A general term used to imply that a part in service (a) has become completely inoperable, (b) is still operable but is incapable of satisfactorily performing its intended function, or (c) has deteriorated seriously, to the point that it has become unreliable or unsafe for continued use.

  • FALSE BOTTOM

An insert put in either member of a die set to increase the strength and improve the life of the die.

  • FALSE BRINELLING

Evenly spaced depressions in a raceway of a rolling-element bearing caused by fretting that occurs when the bearing is subjected to vibration while it is not rotating.

  • FALSE INDICATION

In nondestructive inspection, an indication that may be interpreted erroneously as an imperfection.

  • FAS 106

An accounting rule established in 1990 that requires companies to change their accounting for the cost of their retirees' future non pension benefits (life insure' and health services). What were once "pay as you go" or "cash basis" expense were changed to an accrual basis. Such costs are now recognized during the employees' working years. When the steel companies shifted to the new accounting rule, most companies charged the "catch-up" to equity in large one-time write-downs as they established the new liabilities on their balance sheets

  • FAS 109

An accounting rule for deferred taxes that requires companies to explain within financial statements the difference between the tax expense found on the income statement and the check actually sent to the Internal Revenue Service (IRS). (T rule superseded FAS 96 and APB 11.). Some steel companies carry net operating losses (NOLs) on their balance sheets assets that can be used to offset future taxes. Under the rules of FAS 109, however, a valuation allowance may be recorded to reduce these NOLs unless there is a high probability that they will be used

  • FASTMET

A process to directly reduce iron ore to metallic iron pellets that can be fed into an electric arc furnace with an equal amount of scrap. This process is designed to bypass the coke oven-blast furnace route to produce hot metal from iron ore. It is also one of several methods that mini-mills might use to reduce their dependence on high-quality scrap inputs (see Direct Reduced Iron and Hot Briquetted Iron)

  • FATIGUE

The phenomenon leading to fracture under repeated or fluctuating stresses having a maximum value less than the tensile strength of the material. Fatigue fractures are progressive, beginning as minute cracks that grow under the action of the fluctuating stress.

  • FATIGUE LIFE

The number of cycles of stress that can be sustained prior to failure for a stated test condition.

  • FATIGUE LIMIT

The maximum stress that presumably leads to fatigue fracture in a specified number of stress cycles. If the stress is not completely reversed, the value of the mean stress, the minimum stress or the stress ratio also should be stated. Compare with endurance limit. fatigue notch factor (Kf)

  • FATIGUE NOTCH SENSITIVITY (Q)

An estimate of the effect of a notch or hole on the fatigue properties of a material; measured by q = (Kf-1)I(Kt-1). A material is said to be fully notch sensitive if q approaches a value of 1.0, it is not notch sensitive if the ratio approaches 0. Kf is the fatigue notch factor, and Kt is the stress-concentration factor, for a specimen of the material containing a notch or hole of a given size and shape.

  • FATIGUE RATIO

The fatigue limit under completely reversed flexural stress divided by the tensile strength for the same alloy and condition.

  • FATIGUE STRENGTH

The maximum stress that can be sustained for a specified number of cycles without failure, the stress being completely reversed within each cycle unless otherwise stated.

  • FATIGUE STRIATIONS

Parallel lines frequently observed in electron microscope fractographs of fatigue fracture surfaces. The lines are transverse to the direction of local crack propagation; the distance between successive lines represents the advance of the crack front during one cycle of stress variation.

  • FATIGUE-STRENGTH REDUCTION FACTOR (KF)

The ratio of the fatigue strength of a member or specimen with no stress concentration to the fatigue strength with stress concentration. Kf has no meaning unless the stress range and the shape, size and material of the member or specimen are stated.

  • FAYING SURFACE

The surface of a piece of metal (or a member) in contact with another to which it is or is to be joined.

  • FEED

The rate at which a cutting tool or grinding wheel advances along or into the surface of a workpiece, the direction of advance depending upon the type of operation involved.

  • FEED LINES

Linear marks on a machined or ground surface that are spaced at intervals equal to the feed per revolution or per stroke.

  • FEEDER (FEEDER HEAD, FEEDHEAD)

A riser.

  • FEEDING

(1) Conveying metal stock or workpieces to a location for use or processing, such as wire to a consumable electrode, strip to a die, or workpieces to an assembler. (2) In casting providing molten metal to a region undergoing solidification, usually at a rate sufficient to fill the mold cavity ahead of the solidification front and to make up for any shrinkage accompanying solidification.

  • FEEDSTOCK

Any raw material

  • FERRIMAGNETIC MATERIAL

A material that macroscopically has properties similar to those of a ferromagnetic material but that microscopically also resembles an antiferromagnetic material in that some of the elementary magnetic moments are aligned antiparallel. If the moments are of different magnitudes, the material may still have a large resultant magnetization.

  • FERRITE

(1) A solid solution of one or more elements in body-centered cubic iron. Unless otherwise designated (for instance, as chromium ferrite), the solute is generally assumed to be carbon. On some equilibrium diagrams, there are two ferrite regions separated by an austenite area. The lower area is alpha ferrite; the upper, delta ferrite. If there is no designation, alpha ferrite is assumed. (2) In the field of magnetics, substances having the general formula: M++O.M2+++O3 the trivalent metal often being iron.

  • FERRITE BANDING

Parallel bands of free ferrite aligned in the direction of working. Sometimes referred to as ferrite streaks.

  • FERRITE NUMBER

An arbitrary, standardized value designating the ferrite content of an austenitic stainless steel weld metal. This value directly replaces percent ferrite or volume percent ferrite and is determined by the magnetic test described in AWS A4.2.

  • FERRITE STREAKS

Same as ferrite banding.

  • FERRITIC

The second-largest class of stainless steel, constituting approximately 25percent of stainless production. Ferritic stainless steels are plain chromium steels with no significant nickel content; the lack of nickel results in lower corrosion resistance than the austenitics (chromium-nickel stainless steels). Ferritics are best suited for general and high temperature corrosion applications rather than services requiring high strength. They are used in automotive trim and exhaust systems, interior architectural trim, and hot water tanks. Two of the most common grades are type 430 (general-purpose grade for many applications, including decorative ones) and type 409 (low-cost grade well suited to withstanding high temperatures)

  • FERRITIC MALLEABLE

See malleable cast iron.

  • FERRITIZING ANNEAL

A treatment given as cast gray or ductile (nodular) iron to produce an essentially ferritic matrix. For the term to be meaningful, the final microstructure desired or the time-temperature cycle used must be specified.

  • FERROALLOY

An alloy or iron that contains a sufficient amount of one or more other chemical elements to be useful as an agent for introducing these elements into molten metal, especially into steel or cast iron.

  • FERROALLOY

A metal product commonly used as a raw material feed in steelmaking, usually containing iron and other metals, to aid various stages of the steelmaking process such as deoxidation, desulfurization, and adding strength. Examples: ferrochrome, ferromanganese, and ferrosilicon

  • FERROCHROME

An alloy of iron and chromium with up to 72percent chromium. Ferrochrome is commonly used as a raw material in the making of stainless steel

  • FERROMAGNETIC MATERIAL

A material that in general exhibits the phenomena of hysteresis and saturation, and whose permeability is dependent on the magnetizing force. Microscopically, the elementary magnets are aligned parallel in volumes called domains. The unmagnetized condition of a ferromagnetic material results from the over-all neutralization of the magnetization of the domains to produce zero external magnetization. Compare with paramagnetic material, diamagnetic material.

  • FERROUS

Metals that consist primarily of iron

  • FERROUS ALLOY

(See Alloy Steel)

  • FIBER

(1) The characteristic of wrought metal that indicates directional properties and is revealed by the etching of a longitudinal section or is manifested by the fibrous or woody appearance of a fracture. It is caused chiefly by the extension of the constituents of the metal, both metallic and nonmetallic, in the direction of working. (2) The pattern of preferred orientation of metal crystals after a given deformation process, usually wiredrawing. See preferred orientation.

  • FIBER STRESS

Local stress through a small area (a point or line) on a section where the stress is not uniform, as in a beam under a bending load.

  • FIBROUS FRACTURE

A fracture where the surface is characterized by a dull gray or silky appearance. Contrast with crystalline fracture.

  • FILAMENTARY SHRINKAGE

A fine network of shrinkage cavities, occasionally found in steel castings, that produces a radiographic image resembling lace.

  • FILE HARDNESS

Hardness as determined by the use of a file of standardized hardness on the assumption that a material that cannot be cut with the file is as hard as, or harder than, the file. Files covering a range of hardnesses may be employed.

  • FILLER

A material used to increase the bulk of a product without adding to its effectiveness in functional performance.

  • FILLER METAL

Metal added in making a brazed, soldered or welded joint.

  • FILLET

(1) A radius (curvature) imparted to inside meeting surfaces. (2) A concave cornerpiece used on foundry patterns.

  • FILLET WELD

A weld, approximately triangular in cross section, joining two surfaces essentially at right angles to each other in a lap, tee or corner joint.

  • FINAL ANNEALING

An imprecise term used to denote the last anneal given to a nonferrous alloy prior to shipment.

  • FINE SILVER

Silver with a fineness of 999; equivalent to a minimum content of 99.9percent Ag with the remaining content unrestricted.

  • FINENESS

A measure of the purity of gold or silver expressed in parts per thousand.

  • FINES

(1) The product that passes through the finest screen in sorting crushed or ground material. (2) Sand grains that are substantially smaller than the predominating size in a batch or lot of foundry sand. (3) The portion of a metal powder composed of particles that are smaller than a specified size, currently less than 44 (m.

  • FINISH

(1) Surface condition, quality or appearance of a metal. (2) Stock on a forging or casting to be removed when finish machined.

  • FINISH

The surface appearance of steel after final treatment

  • FINISH ALLOWANCE

The amount of excess metal surrounding the intended final configuration of a formed part sometimes called forging envelope, machining allowance, or cleanup allowance.

  • FINISH GRINDING

The final grinding action on a workpiece where the objectives are surface finish and dimensional accuracy.

  • FINISH MACHINING

A machining process analogous to finish grinding.

  • FINISHED STEEL

Steel that is ready for the market and has been processed beyond the stages of billets, blooms, sheet bars, slabs and wire rods.

  • FINISHING DIE

The die used to make the final impression on a forging. Some- times called finisher.

  • FINISHING FACILITIES

The portion of the steelmaking complex that processes semi-finished steel (slabs or billets) into forms that can be used by others. Finishing operations can include rolling mills, pickle lines, tandem mills, annealing facilities, and temper mills

  • FINISHING TEMPERATURE

The temperature at which hot working is completed.

  • FINMET

The process reduces iron ore fines with gas in a descending series of fluidized bed reactors. The reduced iron is hot briquetted

  • FIRE SCALE

Intergranular copper oxide remaining below the surface of silvercopper alloys that have been annealed and pickled.

  • FIRE-REFINED COPPER

Copper that has been refined by the use of a furnace process only, including refinery shapes and, by extension, fabricators' products made therefrom. Usually, when this term is used alone it refers to fire-refined tough pitch copper without elements other than oxygen being present in significant amounts.

  • FISH EYES

Areas on a fractured steel surface having a characteristic white crystalline appearance.

  • FISHSCALE

A scaly appearance in a porcelain enamel coating in which the evolution of hydrogen from the basis metal (iron or steel) causes loss of adhesion between the enamel and basis metal. Individual scales are usually small, but have been observed up to 25 mm or more in diameter. The scales are somewhat like blisters that have cracked part way around the perimeter but still remain attached to the coating around the rest of the perimeter; if detached completely, it is one form of pop-off.

  • FISHTAIL

(1) In roll forging, the excess trailing end of a forging. It is often used, before being trimmed off, as a tong hold for a subsequent forging operation. (2) In hot rolling or extrusion, the imperfectly shaped trailing end of a bar or special section that must be cut off and discarded as mill scrap. fit. The amount of clearance or interference between mating parts is called actual fit. Fit is the preferable term for the range of clearance or interference that may result from the specified limits on dimensions (limits of size). Refer to ANSI standards.

  • FIXED-FEED GRINDING

Grinding where the wheel is fed into the work, or vice versa, by given increments or at a given rate.

  • FIXED-POSITION WELDING

Welding in which the work is held in a stationary position.

  • FIXTURE

A positioning device to hold the workpiece only.

  • FLAKE POWDER

Metal powder in the form of flat or scalelike particles, relatively thin.

  • FLAKES

Short discontinuous internal fissures in ferrous metals attributed to stresses produced by localized transformation and decreased solubility of hydrogen during cooling after hot working. In a fractured surface, flakes appear as bright silvery areas; on an etched surface, they appear as short discontinuous cracks. Also called shatter cracks or snowflakes.

  • FLAME ANNEALING

Annealing in which the heat is applied directly by a flame.

  • FLAME CLEANING

Cleaning metal surfaces of scale, rust, dirt and moisture by use of a gas flame.

  • FLAME HARDENING

A process for hardening the surfaces of hardenable ferrous alloys in which an intense flame is used to heat the surface layers above the upper transformation temperature, whereupon the workpiece is immediately quenched.

  • FLAME SPRAYING

Thermal spraying in which a coating material is fed into an oxyfuel gas flame, where it is melted. Compressed gas may or may not be used to atomize the coating material and propel it onto the substrate.

  • FLAME STRAIGHTENING

Correcting distortion in metal structures by localized heating with a gas flame. flank. The end surface of a tool that is adjacent to the cutting edge and below it when the tool is in a horizontal position, as for turning. See sketch accompanying single-point tool.

  • FLANK WEAR

The loss of relief on the flank of the tool behind the cutting edge due to rubbing contact between the work and the tool during cutting; measured in terms of linear dimension behind the original cutting edge.

  • FLAPPING

In copper refining, hastening oxidation of molten copper by striking through the slag-covered surface of the melt with a rabble just before the bath is poled.

  • FLARE TEST

A test applied to tubing, involving a tapered expansion over a cone. Similar to pin expansion test. Flaring

  • FLASH BUTT WELDING

See flash welding.

  • FLASH LAND

Relief at the parting line of a set of closed-die forging dies that is designed either to restrict or to encourage growth of flash, whichever is required to ensure complete filling of the finishing impression.

  • FLASH LINE

The line of location of flash formed around a forging or casting.

  • FLASH PLATE

A very thin final electrodeposited film of metal.

  • FLASH WELDING

A resistance welding process that joins metals by first heating abutting surfaces by passing an electric current across the joint, then forcing the surfaces together by the application of pressure.

  • FLASHBACK

The recession of a flame into or in back of the interior of a torch.

  • FLASHING

In flash welding, the heating portion of the cycle, consisting of a series of rapidly recurring localized short circuits followed by molten metal expulsions, during which time the surfaces to be welded are moved one toward the other at a predetermined speed.

  • FLASK

A metal or wood frame used for making and holding a sand mold. The upper part is called the cope; the lower, the drag.

  • FLAT DIE FORGING

Forging metal between flat or simple contour dies by repeated strokes and manipulation of the workpiece. Also known as open die forging, hand forging or smith forging.

  • FLAT DRILL

A rotary end-cutting tool constructed from a flat piece of material, provided with suitable cutting lips at the cutting end.

  • FLAT WIRE

A roughly rectangular or square mill product, narrower than strip, in which all surfaces are rolled or drawn without any previous slitting, shearing or sawing. flaw. A nonspecific term often used to imply a cracklike discontinuity. See preferred terms discontinuity, imperfection, defect.

  • FLAT-POSITION WELDING

Welding from the upper side, the face of the weld being horizontal. Also called down-hand welding.

  • FLAT-ROLLED STEEL

Category of steel that includes sheet, strip, and tin plate, among others

  • FLATTENING

(1) A preliminary operation performed on forging stock so as to position the metal for a subsequent forging operation. (2) Removing irregularities or distortion in sheets or plates by a method such as roller leveling or stretcher leveling.

  • FLATTENING TEST

A quality test for tubing in which a specimen is flattened to a specified height between parallel plates.

  • FLEX ROLL

A movable jump roll designed to push up against a sheet as it passes through a roller leveler. The flex roll can be adjusted to deflect the sheet any amount up to the roll diameter.

  • FLEX ROLLING

Passing sheets through a flex-roll unit to minimize yield-point elongation so as to reduce the tendency for stretcher strains to appear during forming.

  • FLEXIBLE CAM

An adjustable pressure control cam of spring steel strips used to obtain varying pressure during a forming cycle.

  • FLOATING DIE

(1) A die mounted in a die holder or a punch mounted in its holder, such that a slight amount of motion compensates for tolerance in the die parts, the work or the press. (2) A die mounted on heavy springs to allow vertical motion in some trimming, shearing and forming operations.

  • FLOATING PLUG

In tube drawing, an unsupported mandrel that locates itself at the die inside the tube causing the reduction of the wall thickness while the die is effecting a reduction of the outside diameter.

  • FLOPPERS

On metals, lines or ridges that are transverse to the direction of rolling and generally confined to the section midway between the edges of a coil as rolled.

  • FLOSPINNING

Forming cylindrical, conical and curvilinear shaped parts by power spinning over a rotating mandrel.

  • FLOTATION

The concentration of valuable minerals from ores by agitation of the ground material with water, oil and flotation chemicals. The valuable minerals are generally wetted by the oil, lifted to the surface by clinging air bubbles and then floated off.

  • FLOW BRAZING

Brazing by pouring hot molten nonferrous filler metal over a joint until the brazing temperature is attained. The filler metal is distributed in the joint by capillary action.

  • FLOW BRIGHTENING

The melting of an electrodeposit, followed by solidification, especially of tin plate.

  • FLOW LINES

(1) Texture showing the direction of metal flow during hot or cold working. Flow lines often can be revealed by etching the surface or a section of a metal part (see macrograph on this page). (2) In mechanical metallurgy, paths followed by minute volumes of metal during deformation.

  • FLOW STRESS

The uniaxial true stress at the onset of plastic deformation in a metal.

  • FLOWABILITY

A characteristic of a foundry sand mixture that enables it to move under pressure or vibration so that it makes intimate contact with all surfaces of the pattern or core box.

  • FLUIDITY

The ability of liquid metal to run into and fill a mold cavity.

  • FLUORESCENCE

The emission of characteristic electromagnetic radiation by a substance as a result of the absorption of electromagnetic or corpuscular radiation having a greater unit energy than that of the fluorescent radiation. It occurs only so long as the stimulus responsible for it is maintained.

  • FLUORESCENT MAGNETIC-PARTICLE INSPECTION

Inspection with either dry magnetic particles or those in a liquid suspension, the particles being coated with a fluorescent substance to increase the visibility of the indications.

  • FLUORESCENT PENETRANT INSPECTION

Inspection using a fluorescent liquid that will penetrate any surface opening; after wiping the surface clean the location of any surface flaws may be detected by the fluorescence, under ultraviolet light, of back-seepage of the fluid.

  • FLUOROSCOPY

An inspection procedure in which the radiographic image of the subject is viewed on a fluorescent screen, normally limited to low-density materials or thin sections of metals because of the low light output of the fluorescent screen at safe levels of radiation.

  • FLUTE

(1) As applied to drills, reamers and taps, the channels or grooves formed in the body of the tool to provide cutting edges and to permit passage of cutting fluid and chips. (2) As applied to milling cutters and hobs, the chip space between the back of one tooth and the face of the following tooth.

  • FLUTING

(1) Forming longitudinal recesses in a cylindrical part, or radial recesses in a conical part. (2) A series of sharp parallel kinks or creases occurring in the arc when sheet metal is roll formed into a cylindrical shape.

  • FLUX

(1) In metal refining, a material used to remove undesirable substances, like sand, ash or dirt, as a molten mixture. It is also used as a protective covering for certain molten metal baths. Lime or limestone is generally used to remove sand, as in iron smelting; sand, to remove iron Oxide in copper refining. (2) In brazing, cutting, soldering or welding, material used to prevent the formation of, or to dissolve and facilitate removal of, oxides and other undesirable substances.

  • FLUX

An iron cleaning agent. Limestone and lime react with impurities within the metallic pool to form a slag that floats to the top of the relatively heavier (and more pure) liquid iron

  • FLUX LINES

Imaginary lines used as a means of explaining the behavior of magetic and other fields. Their concept is based on the pattern of lines produced when magetic particles are sprinkled over a permanent magnet. Sometimes called magetic lines of force.

  • FLUX-CORED ARC WELDING

An arc welding process that joins metals by heating them with an arc between a continuous tubular filler-metal electrode and the work. Shielding is provided by a flux contained within the consumable tubular electrode. Additional shielding may or may not be obtained from an externally supplied gas or gas mixture. See also electrogas welding.

  • FLY ASH

A finely divided siliceous material formed during the combustion of coal, coke or other solid fuels.

  • FLYING SHEAR

A machine for cutting continuous rolled products to length that does not require a halt in rolling, but rather moves along the runout table at the same speed as the product while performing the cutting, then returns to the starting point in time to cut the next piece.

  • FOB PRICING

Free On Board Pricing - Phrase that explains whether the transportation costs steel are included. "FOB Mill" is the price of steel at the mill, not including hipping

  • FOG QUENCHING

Quenching in a fine vapor or mist.

  • FOIL

Metal in sheet form less than 0.15 mm (0.006 in.) in thickness.

  • FOLLOW DIE

A progressive die consisting of two or more parts in a single holder, used with a separate lower die to perform more than one operation (such as piercing and blanking) on a part at two or more stations.

  • FOOT PRESS

A small press with low capacity actuated by foot pressure on a treadle.

  • FORCE FIT

Any of various interference fits between parts assembled under various amounts of force.

  • FOREHAND WELDING

Welding in which the palm of the principal hand (torch or electrode hand) of the welder faces the direction of travel. It has special sigificance in oxyfuel gas welding in that the flame is directed ahead of the weld bead, which provides preheating.

  • FORGE DELAY TIME

In spot, seam or projection welding, the time between the start of the welding, current or weld interval and the application of forging pressure.

  • FORGE WELDING

Solid state welding in which metals are heated in a forge (in air) then welded together by applying pressure or blows sufficient to cause permanent deformation at the interface.

  • FORGEABILITY

Term used to describe the relative ability of material to flow under a compressive load without rupture.

  • FORGING

Plastically deforming metal, usually hot, into desired shapes with compressive force, with or without dies.

  • FORGING BILLET

A wrought metal slug used as forging stock.

  • FORGING ENVELOPE

See finish allowance.

  • FORGING INGOT

A cast metal slug used as forging stock.

  • FORGING MACHINE

A type of forging equipment, related to the mechanical press, in which the main forming energy is applied horizontally to the workpiece, which is held by dies. Commonly called upsetter or header.

  • FORGING PLANE

In forging, the plane that includes the principal die face and that is perpendicular to the direction of ram travel. When parting surfaces of the dies are flat, the forging plane coincides with the parting line. Contrast parting plane.

  • FORGING RANGE

Temperature range in which a metal can be forged successfully.

  • FORGING ROLLS

A machine used in roll forging. Also called gap rolls.

  • FORGING STOCK

A rod, bar or other section used to make forgings.

  • FORM BLOCK

Tooling, usually the male part, used for forming sheet-metal contours, being generally employed in the rubber-pad process.

  • FORM CUTTER

Any cutter, profile sharpened or cam relieved, shaped to produce a specified form on the work. Form die

  • FORM GRINDING

Grinding with a wheel having a contour on its cutting face that is a mating fit to the desired form.

  • FORM ROLLING

Hot rolling to produce bars having contoured cross sections; not to be confused with roll forming of sheet metal or with roll forging.

  • FORM TOOL

A single-edge, nonrotating cutting tool, circular or flat, that produces its inverse or reverse form counterpart upon a workpiece.

  • FORMABILITY

The relative ease with which a metal can be shaped through plastic deformation. See drawability.

  • FORMING

Making a change, with the exception of shearing or blanking, in the shape or contour of a metal part without intentionally altering the thickness.

  • FORM-RELIEVED CUTTER

A cutter so relieved that by grinding only the tooth face the original form is maintained throughout its life.

  • FORWARD EXTRUSION

Same as direct extrusion. See extrusion.

  • FOUNDRY

A commercial establishment or building where metal castings are produced.

  • FOUR-HIGH MILL

A type of rolling mill commonly used for flat-rolled mill products, in which two large-diameter backup rolls are employed to reinforce two smaller working rolls, which are in contact with the product. Either the working rolls or the backup rolls may be driven. Compare with two-high mill, cluster mill.

  • FOUR-POINT PRESS

A press whose slide is actuated by four connections and four cranks, eccentrics, or cylinders, the chief merit being to equalize the pressure at the corners of the slides.

  • FRACTION

In powder metallurgy, the portion of a powder sample that lies between two stated particle sizes. Synonymous with cut.

  • FRACTOGRAPHY

Descriptive treatment of fracture, especially in metals, with specific reference to photographs of the fracture surface. Macrofractography involves photographs at low magnification; microfractography, at high magification.

  • FRACTURE MECHANICS

See linear elastic fracture mechanics.

  • FRACTURE TEST

Breaking a specimen and examining the fractured surface with the unaided eye or with a low-power microscope to determine such things as composition, grain size, case depth or soundness.

  • FRAGMENTATION

The subdivision of a grain into small discrete crystallites outlined by a heavily deformed network of intersecting slip as a result of cold working. These small crystals or fragments differ from one another in orientation and tend to rotate to a stable orientation determined by the slip systems.

  • FRECKLING

A type of segregation revealed as dark spots on a macroetched specimen of a consumable-electrode vacuum arc remelted alloy.

  • FREE CARBON

The part of the total carbon in steel or cast iron that is present in elemental form as graphite or temper carbon. Contrast with combined carbon.

  • FREE FERRITE

Ferrite that is formed directly from the decomposition of hypoeutectoid austenite during cooling, without the simultaneous formation of cementite. Also proeutectoid ferrite.

  • FREE FIT

Various clearance fits for assembly by hand and free rotation of parts. See running fit.

  • FREE MACHINING

Pertains to the machining characteristics of an alloy to which one or more ingredients have been introduced to give small broken chips, lower power consumption, better surface finish and longer tool life. Among such additions are sulfur or lead to steel, lead to brass, lead and bismuth to aluminum, sulfur or selenium to stainless steel.

  • FREEZING RANGE

That temperature range between liquidus and solidus temperatures in which molten and solid constituents coexist.

  • FREIGHT EQUALIZATION

A common industry practice when a mill sells steel out of its geographic area; it will assume any extra shipping costs (relative to the competition) to quote the customer an equivalent price to get the business

  • FRETTING

A type of wear that occurs between tight-fitting surfaces subjected to cyclic relative motion of extremely small amplitude. Usually, fretting is accompanied by corrosion, especially of the very fine wear debris. Also referred to as fretting corrosion, false brinelling (in rolling-element bearings), friction oxidation, chafing fatigue, molecular attrition and wear oxidation.

  • FRETTING FATIGUE

Fatigue fracture that initiates at a surface area where fretting has occurred.

  • FRICTION WELDING

A solid state process in which materials are welded by the heat obtained from rubbing together surfaces that are held against each other under pressure.

  • FULL ANNEALING

An imprecise term that denotes an annealing cycle to produce minimum strength and hardness. For the term to be meaningful, the composition and starting condition of the material and the time-temperature cycle used must be stated.

  • FULL CENTER

Mild waviness down the center of a sheet or strip.

  • FULL HARD

A temper of nonferrous alloys and some ferrous alloys corresponding approximately to a cold worked state beyond which the material can no longer be formed by bending. In specifications, a full hard temper is commonly defined in terms of minimum hardness or minimum tensile strength (or, alternatively, a range of hardness or strength) corresponding to a specific percentage of cold reduction following a full anneal. For aluminum, a full hard temper is equivalent to a reduction of 75 percent from dead soft; for austenitic stainless steels, a reduction of about 50 to 55 percent.

  • FULL-AUTOMATIC PLATING

Electroplating in which the work is automatically conveyed through the complete cycle.

  • FULLER

In preliminary forging, the portion of a die that reduces the cross-sectional area between the ends of the stock and permits the metal to move outward.

  • FURNACE BRAZING

A mass-production brazing process in which the filler metal is preplaced on the joint, then the entire assembly is heated to brazing temperature in a furnace. Usually, a protective furnace atmosphere is required, and wetting of the joint surfaces is accomplished without using a brazing flux.

  • FUSION

A change of state from solid to liquid; melting.

  • FUSION FACE

A surface of the base metal that will be melted during welding.

  • FUSION WELDING

Any welding process in which filler metal and base metal (substrate), or base metal only, are melted together to complete the weld.

  • FUSION ZONE

In a weldment, the area of base metal melted as determined on a cross section through the weld.

  • FUX-OXYGEN CUTTING

Oxygen cutting with the aid of a flux.

  • GAGE

(1) The thickness (or diameter) of sheet or wire. The various standards are arbitrary and differ, ferrous from nonferrous products and sheet from wire. (2) An instrument used to measure thickness or length. (3) An aid for visual inspection that enables the inspector to determine more reliably whether the size or contour of a formed part meets dimensional requirements.

  • GAGE LENGTH

The original length of that portion of the specimen over which strain, change of length and other characteristics are measured.

  • GAGGER

An irregular-shaped piece of metal used for reinforcement and support in a sand mold.

  • GALLING

A condition whereby excessive friction between high spots results in localized welding with subsequent spelling and a further roughening of the rubbing surfaces of one or both of two mating parts.

  • GALVALUME(R)

Steel sheet with a unique coating of 55percent aluminum and 45percent zinc that resists corrosion. The coating is applied in a continuous hot-dipped process, which improves the steels weather resistance. Galvalume is a trademark of BHP Steel and the product is popular in the metal building market

  • GALVANIC CELL

A cell in which chemical change is the source of electrical energy. It usually consists of two dissimilar conductors in contact with each other and with an electrolyte, or of two similar conductors in contact with each other and with dissimilar electrolytes.

  • GALVANIC CORROSION

Corrosion associated with the current of a galvanic cell consisting of two dissimilar conductors in an electrolyte or two similar conductors in dissimilar electrolytes. Where the two dissimilar metals are in contact, the resulting reaction is referred to as couple action.

  • GALVANIC SERIES

A series of metals and alloys arranged according to their relative electrode potentials in a specified environment. Compare with electromotive series.

  • GALVANIZE

To coat a metal surface with zinc using any of various processes.

  • GALVANIZED STEEL

Steel coated with a thin layer of zinc to provide corrosion resistance in underbody auto parts, garbage cans, storage tanks, or fencing wire. Sheet steel normally must be cold-rolled prior to the galvanizing stage

  • GALVANNEAL

To produce a zinc-iron alloy coating on iron or steel by keeping the coating molten after hot-dip galvanizing until the zinc alloys completely with the basis metal.

  • GAMMA IRON

The face-centered cubic form of pure iron, stable from 910 to 1400 �C (1670 to 2550 �F).

  • GAMMA RAY

Short wavelength electromagnetic radiation, similar to x-rays but of nuclear origin, with a range of wavelengths from about 10-14 to 10-10 m.

  • GAMMA STRUCTURE

A Hume-Rothery designation for structurally analogous phases or electron compounds that have ratios of 21 valence electrons to 13 atoms; generally, a large complex cubic structure. Not to be confused with gamma phase on a constitution diagram.

  • GANG MILLING

Milling with several cutters mounted on the same arbor or with workpieces similarly positioned for cutting either simultaneously or consecutively during a single setup.

  • GANG SLITTER

A machine with a number of pairs of rotary cutters spaced on two parallel shafts, used for slitting sheet metal into strips or for trimming the edges of sheets.

  • GANGUE

The worthless portion of an ore that is separated from the desired part before smelting is commenced.

  • GAP

The root opening in a weld joint.

  • GAP-FRAME PRESS

A general classification of presses in which the uprights or housings are made in the form of a letter "C", thereby making three sides of the die space accessible.

  • GAS CYANIDING

A misnomer for carbonitriding.

  • GAS HOLES

Holes in castings or welds that are formed by gas escaping from molten metal as it solidifies. Gas holes may occur individually, in clusters, or distributed throughout the solidified metal.

  • GAS METAL-ARC WELDING

A process for welding metals together by heating them with an arc between a continuous filler-metal electrode and the work. Shielding is obtained entirely from an externally supplied gas or gas mixture. Some methods of this process are called MIG or CO2 welding. See also electrogas welding, pulsed power welding.

  • GAS PLATING

Same as vapor plating.

  • GAS POCKET

A cavity caused by entrapped gas.

  • GAS POROSITY

Fine holes or pores within a metal that are caused by entrapped gas or by evolution of dissolved gas during solidification.

  • GAS TUNGSTEN-ARC CUTTING

An arc-cutting process in which metals are severed by melting them with an arc between a single tungsten (nonconsumable) electrode and the work.Shielding is obtained from a gas or gas mixture.

  • GAS TUNGSTEN-ARC WELDING

A fusion welding process in which metals are joined by heating them with an electric arc between a nonconsumable tungsten electrode and the work. A gas or gas mixture shields the arc and the weld puddle. Pressure may or may not be applied to the joint, and filler metal may or may not be added. Sometimes referred to as TIG welding. Gas welding.

  • GAS-SHIELDED ARC WELDING

Arc welding in which the arc and molten metal are shielded from the atmosphere by a stream of gas, such as argon, helium, argon-hydrogen mixtures or carbon dioxide.

  • GASSING

(1) Absorption of gas by a metal. (2) Evolution of gas from a metal during melting operations or on solidification. (3) The evolution of gas from an electrode during electrolysis.

  • GATE

The portion of the runner in a mold through which molten metal enters the mold cavity. Sometimes the generic term is applied to the entire network of connecting channels that conduct metal into the mold cavity.

  • GATED PATTERN

A pattern that includes not only the contours of the part to be cast, but also the gates.

  • GATHERING

A forging operation that increases the cross section of part of the stock; usually a preliminary operation.

  • GATHERING STOCK

Any operation whereby the cross section of a portion of the forging stock is increased above its original size.

  • GAUGE

The thickness of sheet steel. Better-quality steel has a consistent gauge to prevent weak spots or deformation

  • GEARED PRESS

A press whose main crank or eccentric shaft is connected by gears to the driving source.

  • GHOST LINES

Lines running parallel to the rolling direction that appear in a panel when it is stretched. These lines may not be evident unless the panel has been sanded or painted. (Not to be confused with leveler lines.)

  • GIBS

Guides that ensure the proper restrained motion of the slide, usually being adjustable to compensate for wear.

  • GLASS ELECTRODE

A glass membrane electrode used to measure pH or hydrogen-ion activity. Glazing

  • GLIDE

(1) Same as slip. (2) A noncrystallographic shearing movement, as one grain over another.

  • GLOBULAR TRANSFER

In consumable electrode arc welding, a type of metal transfer in which molten filler metal passes across the arc as large droplets. Compare with spray transfer, short circuiting transfer.

  • GLOSSARY OF STEEL TERMS
  • GOLD FILLED

Covered on one or more surfaces with a layer of gold alloy to form a clad metal. By commercial agreement, a quality mark showing the quantity and fineness of gold alloy may be affixed, indicating the actual proportional weight and karat fineness of the gold alloy cladding. For example, "1/10 12K Gold Filled' means that the article consists of base metal covered on one or more surfaces with a gold alloy of 12-karat fineness comprising 1/10th part by weight of the entire metal in the article. No article having a gold alloy coating of less than 10-karat fineness may have an quality mark affixed. No article having a gold alloy portion of less than 1/20th by weight may be marked "Gold Filled", but may be marked "Rolled Gold Plate" provided that the proportional fraction and fineness designation precedes. These standards do not necessarily apply to watch cases.

  • G-P ZONE

A Guinier-Preston zone.

  • GRAIN

An individual crystal in a polycrystalline metal or alloy; it may or may not contain twinned regions and subgrains.

  • GRAIN FINENESS NUMBER

A weighted average grain size of a granular material. The AFS Grain fineness number is calculated with prescribe weighting factors from the standard screen analysis.

  • GRAIN FLOW

Fiberlike lines appearing on polished and etched sections forgings, which are caused by orientation of the constituents of the metal in the direction of working during forging. Grain flow produced by proper die design can improve require mechanical properties of forgings.

  • GRAIN GROWTH

An increase in the average size of the grains in polycrystalline metal, usually as a result of heating at elevated temperature.

  • GRAIN REFINER

A material added to molten metal to induce a finer the normal grain size in the final structure.

  • GRAIN SIZE

(1) For metals, a measure of the areas or volumes of grains in a polycrystalline material, usually expressed as an average when the individual sizes are fairly uniform. In metals containing two or more phases, the grain size refers to that of the matrix unless otherwise specified. Grain sizes are reported in terms of number of grains per unit area or volume, average diameter, or as a grain-size number derived from area measurements. (2) For grinding wheels, see preferred term, grit size.

  • GRAIN-ORIENTED

The metal's grain runs parallel within the steel, permitting easy magnetization along the length of the steel. Although grain-oriented steel may be twice as expensive to produce, its magnetic directional characteristics enable power transformers, made from this metal, to absorb less energy during operation

  • GRANULAR FRACTURE

A type of irregular surface produced when metal is broken that is characterized by a rough, grainlike appearance as differentiated from a smooth silky, or fibrous, type. It can be subclassified into transgranular and intergranular forms. This type of fracture is frequently called crystalline fracture, but the inference that the metal broke because it "crystallized" is not justified because all metals are crystalline when in the solid state. Contrast with fibrous fracture, silky fracture.

  • GRANULAR POWDER

Particles of metal powder having approximately equidimensional nonspherical shapes.

  • GRANULATED METAL

Small pellets produced by putting liquid metal through a screen or by dropping it onto a revolving disk, and, in both instances, chilling with water. Granulation

  • GRAPHITIC CARBON

Free carbon in steel or cast iron.

  • GRAPHITIC CORROSION

Corrosion of gray iron in which the iron matrix is selectively leached away, leaving a porous mass of graphite behind; it occurs in relatively mild aqueous solutions and on buried pipe and fittings.

  • GRAPHITIC STEEL

Alloy steel made so that part of the carbon is present as graphite.

  • GRAPHITIZATION

Formation of graphite in iron or steel. Where graphite is formed during solidification, the phenomenon is called primary graphitization; where formed later by heat treatment, secondary graphitization.

  • GRAPHITIZING

Annealing a ferrous alloy in such a way that some or all of the carbon is precipitated as graphite.

  • GRAVITY HAMMER

A class of forging hammer wherein energy for forging is obtained by the mass and velocity of a freely falling ram and the attached upper die. Examples: board hammers and air-lift hammers.

  • GRAVITY SEGREGATION

Variable composition of a casting or ingot caused by the settling out of heavy constituents, or rising of light constituents, before or during solidification.

  • GRAY CAST IRON

A cast iron that gives a gray fracture due to the presence of flake graphite. Often called gray iron.

  • GREEN COMPACT

An unsintered powder metallurgy compact.

  • GREEN DENSITY

Same as pressed density.

  • GREEN ROT

A form of high-temperature attack on stainless steels, nickel chromium alloys and nickel-chromium-iron alloys subjected to simultaneous oxidation and carburization. Basically, attack occurs by first precipitating chromium as chromium carbide, then oxidizing the carbide particles.

  • GREEN SAND

A naturally bonded sand, or a compounded molding sand mixture, that has been "tempered" with water and used while still moist.

  • GREEN SAND CORE

(1) A core made of green sand and used as rammed. (2) A sand core that is used in the unbaked condition.

  • GREEN SAND MOLD

A casting mold composed of moist prepared molding sand. Contrast with dry sand mold.

  • GREENFIELD STEEL MILL

New mill that is built "from scratch," presumably on a green field

  • GRINDABILITY

Relative ease of grinding, analogous to machinability.

  • GRINDABILITY INDEX

A measure of the grindability of a material under specified grinding conditions, expressed in terms of volume of material removed per unit volume of wheel wear.

  • GRINDING

Removing material from a workpiece with a grinding wheel or abrasive belt. Grinding burn

  • GRINDING CRACKS

Shallow cracks formed in the surface of relatively hard materials because of excessive grinding heat or the high sensitivity of the material. See grinding sensitiuity.

  • GRINDING FLUID

Grinding fluid.

  • GRINDING OIL

An oil-type grinding fluid; it may contain additives, but not water.

  • GRINDING RELIEF

A groove or recess located at the boundary of a surface to permit the corner of the wheel to overhang during grinding.

  • GRINDING SENSITIVITY

Susceptibility of a material to surface damage such as grinding cracks; it can be affected by such factors as hardness, microstructure, hydrogen content and residual stress.

  • GRINDING STRESS

Grinding stress.

  • GRINDING WHEEL

A cutting tool of circular shape made of abrasive grains bonded together

  • GRIT BLASTING

Grit blasting.

  • GRIT SIZE

Nominal size of abrasive particles in a grinding wheel corresponding to the number of openings per linear inch in a screen through which the particles can just pass. Sometimes, but inadvisedly, called grain size.

  • GRIZZLY

A set of parallel bars (or grating) used for the coarse separation or screening of ores, rock or other material.

  • GROOVE ANGLE

The total included angle of the groove between parts to be joined. Thus, the sum of two bevel angles, either or both of which may be zero degrees.

  • GROOVE FACE

The portion of a surface or surfaces of a member included in a groove. See sketch accompanying root of joint.

  • GROSS POROSITY

In weld metal or in a casting, pores, gas holes or globular voids that are larger and in much greater number than obtained in good practice.

  • GROUND CONNECTION

In arc welding, a device used for attaching the work lead (ground cable) to the work.

  • GROWTH

In cast iron, a permanent increase in dimensions resulting from repeated or prolonged heating at temperatures above 480 �C (900 �F) due either to graphitizing of carbides or to oxidation.

  • GUARD

(1) A device, often made of sheet metal or wire screening, that prevents accidental contact with moving parts of machinery. (2) In electroplating, same as robber.

  • GUERIN FORMING

A trade-name process. See rubber-pad forming.

  • GUIDE MILL

A small hand mill with several stands in a train and with guides for the work at the entrance to the rolls.

  • GUIDED BEND TEST

A test in which the specimen is bent to a definite shape by means of a jig.

  • GUINIER-PRESTON (G-P) ZONE

A small precipitation domain in a supersaturated metallic solid solution. A G-P zone has no well-defined crystalline structure of its own and contains an abnormally high concentration of solute atoms. The formation of G-P zones constitutes the first stage of precipitation and is usually accompanied by a change in properties of the solid solution in which they occur.

  • GUN DRILL

A drill, usually with one or more flutes and with coolant passages through the drill body, used for deep hole drilling.

  • HABIT PLANE

The plane or system of planes of a crystalline phase along which some phenomenon such as twinning or transformation occurs.

  • HALF CELL

An electrode immersed in a suitable electrolyte, designed for measurements of electrode potential.

  • HALF HARD

A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength about midway between that of dead soft and full hard tempers.

  • HALL PROCESS

A commercial process for winning aluminum from alumina by electrolytic reduction of a fused bath of alumina dissolved in cryolite.

  • HAMMER FORGING

Forging in which the work is deformed by repeated blows. Compare with press forging.

  • HAMMER WELDING

Forge welding by hammering.

  • HAMMERING

Beating metal sheet into a desired shape either over a form or on a high-speed mechanical hammer and a similar anvil to produce the required dishing or thinning.

  • HAND BRAKE

A small manual folding machine designed to bend sheet metal, being similar in design and purpose to a press brake.

  • HAND FORGING

See flat die forging.

  • HANDLING BREAKS

Irregular breaks caused by improper handling of sheets during processing. These breaks result from the bending or sagging of the sheets while being handled.

  • HANSGIRG PROCESS

A process for producing magnesium by the reduction of magnesium oxide with carbon.

  • HARD CHROMIUM

Chromium electrodeposited for engineering purposes (such as increasing the wear resistance of sliding metal surfaces) rather than as a decorative coating. It is usually applied directly to basis metal and is customarily thicker than a decorative deposit, but not necessarily harder.

  • HARD DRAWN

An imprecise term applied to drawn products, such as wire and tubing, that indicates substantial cold reduction without subsequent annealing. Compare with light drawn.

  • HARD FACING

Depositing filler metal on a surface by welding, spraying or braze welding to increase resistance to abrasion, erosion, wear, galling impact or cavitation damage.

  • HARD HEAD

A hard, brittle, white residue obtained in refining tin by liquation, containing, among other things tin, iron, arsenic and copper. Also, a refractory lump of ore only partly smelted.

  • HARD SURFACING

Same as hard facing.

  • HARD TEMPER

Same as full hard temper.

  • HARDENABILITY

The relative ability of a ferrous alloy to form martensite when quenched from a temperature above the upper critical temperature. Hardenability is commonly measured as the distance below a quenched surface where the metal exhibits a specific hardness (50 HRC, for example) or a specific percentage of martensite in the microstructure.

  • HARDENER

An alloy, rich in one or more alloying elements, added to a melt to permit closer composition control than possible by addition of pure metals or to introduce refractory elements not readily alloyed with the base metal. Sometimes called master alloy or rich alloy.

  • HARDENING

Increasing hardness by suitable treatment, usually involving heating and cooling. When applicable, the following more specific terms should be used: age hardening, case hardening, flame hardening, induction hardening, precipitation hardening and quench hardening.

  • HARDENING

WHAT. Process that increases the hardness of steel, i.e., the degree to which steel will resist cutting, abrasion, penetration, bending, and stretching. WHY. The increased endurance provided by hardening makes steel suitable for additional applications. HOW. Hardening can be achieved through various methods, including 1) heat treatment, where the properties of steel are altered by subjecting the steel to a series of temperature changes; and 2) cold working, in which changes in the structure and shape of steel are achieved through rolling, hammering, or stretching the steel at a relatively low temperature

  • HARDNESS

Resistance of metal to plastic deformation, usually by indentation. However, the term may also refer to stiffness or temper, or to resistance to scratching, abrasion or cutting. Indentation hardness may be measured by various hardness tests such as Brinell, Rockwell and Vickers.

  • HARING CELL

A four-electrode cell for measurement of electrolyte resistance and electrode polarization during electrolysis.

  • HARTMANN LINES

Same as L�ders lines.

  • H-BAND STEEL

Alloy steel produced to specified limits of hardenability; the chemical composition range may be slightly different from that of the corresponding grade of ordinary alloy steel.

  • HEADER

See upsetter.

  • HEADING

Upsetting wire, rod or bar stock in dies to form parts that usually have some of the cross-sectional area larger than the original.

  • HEALED-OVER SCRATCH

A scratch that occurred in an earlier mill operation and was partially masked in subsequent rolling. It may open up during forming.

  • HEARTH

The bottom portion of certain furnaces, such as the blast furnace, air furnace and other reverberatory furnaces, that supports the charge and sometimes collects and hold molten metal.

  • HEAT (OF STEEL)

A batch of refined steel. A basic oxygen or electric furnace full of steel. One heat of steel will be used to cast several slabs, blooms or billets

  • HEAT CHECK

A pattern of parallel surface cracks that are formed by alternate rapid heating and cooling of the extreme surface metal, sometime found on forging dies and piercing punches. There may be two sets of parallel cracks, one set perpendicular to the other.

  • HEAT TIME

In multiple-impulse or seam welding, the time that the current flows during any one impulse.

  • HEAT TINTING

Coloration of a metal surface through oxidation by heating to reveal details of the microstructure.

  • HEAT TREATABLE ALLOY

An alloy that can be hardened by heat treatment.

  • HEAT TREATING FILM

A thin coating or film, usually an oxide, formed on the surface of metals during heat treatment.

  • HEAT TREATMENT

Heating and cooling a solid metal or alloy in such a way as to obtain desired conditions or properties. Heating for the sole purpose of hot working is excluded from the meaning of this definition.

  • HEAT TREATMENT

WHAT. Altering the properties of steel by subjecting it to a series of temperature changes. WHY. To increase the hardness, strength, or ductility of steel so that it is suitable for additional applications. HOW. The steel is heated and then cooled as necessary to provide changes in the structural form that will impart the desired characteristics. The time spent at each temperature and the rates of cooling have significant impact on the effect of the treatment

  • HEAT-AFFECTED ZONE

That portion of the base metal that was not melted during brazing, cutting or welding, but whose microstructure and mechanical properties were altered by the heat.

  • HEAT-RESISTING ALLOY

An alloy developed for very high temperature service where relatively high stresses (tensile, thermal, vibratory or shock) are encountered and where oxidation resistance is frequently required.

  • HEAVY STRUCTURAL SHAPES

A general term given to rolled flanged sections that have at least one dimension of their cross sections three inches or greater. The category includes beams, channels, tees and zees if the depth dimension is three inches or greater, and angles if the length of the leg is three inches or greater

  • HEMMING

Forming of an edge by bending the metal back on itself.

  • HERF

Common abbreviation for high energy-rate forging or high-energy rate forming.

  • HERRINGBONE PATTERN

Same as chevron pattern.

  • HEYN STRESSES

Same as microscopic stresses.

  • HIGH RESIDUAL PHOSPHORUS COPPER

Deoxidized copper with residual phosphorus present in amounts (usually 0.013 to 0.04 percent) generally sufficient to decrease appreciably the conductivity of the copper.

  • HIGH-CARBON STEEL

Steel with more than 0.3percent carbon. The more carbon that is dissolved in the iron, the less formable and the tougher the steel becomes. High-carbon steel's hardness makes it suitable for plow blades, shovels, bedsprings, cutting edges, or other high wear applications

  • HIGH-CONDUCTIVITY COPPER

Copper that, in the annealed condition, has a minimum electrical conductivity of 100percent IACS as determined in accordance with ASTM methods of testing.

  • HIGH-ENERGY-RATE FORGING

Producing forgings at extremely high ram velocities resulting from the sudden release of a compressed gas against a free piston. Forging is usually completed in one blow. Also known as HERF processing, high velocity forging, high speed forging.

  • HIGH-ENERGY-RATE FORMING

A group of special forming processes in which metal undergoes deformation at high velocity, usually at least ten times the velocity of 0.2 to 6 m/s (0.5 to 20 ft/s) achieved in conventional forming. Commonly abbreviated HERF. Explosive forming, electrohydraulic forming and electromagnetic forming are the most common HERF processes.

  • HIGH-FREQUENCY RESISTANCE WELDING

A resistance-welding process that produces coalescence of metals with the heat generated from the resistance of the workpieces to a high frequency alternating current in the 10 to 500 kHz range and the rapid application of an upsetting force after heating is substantially completed. The path of the current in the workpiece is controlled by the use of the proximity effect (the feed current follows closely the return current conductor).

  • HIGHLIGHTING

Buffing or polishing selected areas of a complex shape to increase the luster or change the color of those areas.

  • HITCH FEED

Feed performed by a reciprocating head or slide carrying a gripper shoe that clamps the stock during the feeding movement and releases it on the return stroke.

  • HOB

A rotary cutting tool with its teeth arranged along a helical thread, used for generating gear teeth or other evenly spaced forms on the periphery of a cylindrical workpiece. The hob and the workpiece are rotated in timed relationship to each other while the hob is fed axially or tangentially across or radially into the workpiece. Hobs should not be confused with multiple-thread milling cutters, rack cutters, and similar tools, where the teeth are not arranged along a helical thread.

  • HOGGING

Machining a part from bar stock, plate or a simple forging in which much of the original stock is removed.

  • HOLD TIME

In resistance welding, the time during which pressure is applied to the work after the current ceases.

  • HOLDDOWN

A plate, a ring or fingers used to hold work stationary during forming, blanking, piercing or shearing.

  • HOLDING FURNACE

A small furnace into which molten metal can be transferred to be held at the proper temperature until it can be used to make castings.

  • HOLE FLANGING

Forming an integral collar around the periphery of a previously formed hole. See extruded hole.

  • HOLIDAYS

Discontinuities in a coating (such as porosity, cracks, gaps and similar flaws) that allow areas of basis metal to be exposed to any corrosive environment that contacts the coated surface.

  • HOME SCRAP

Waste steel that is generated from within the steel mill, through edge trimming and rejects. It normally is sent directly back to the furnace

  • HOMOGENEOUS CARBURIZING

Use of a carburizing process to convert a lowcarbon ferrous alloy to one of uniform and higher carbon content throughout the section.

  • HOMOGENIZING

Holding at high temperature to eliminate or decrease chemical segregation by diffusion.

  • HONING

A low-speed finishing process used chiefly to produce uniform high dimensional accuracy and fine finish most often on inside cylindrical surfaces. In honing, very thin layers of stock are removed by simultaneously rotating and reciprocating a bonded abrasive stone or stick that is pressed against the surface being honed with lighter force than is typical of grinding.

  • HOOKER PROCESS

Extrusion of a hollow billet or cup through an annulus formed by the die aperture and the mandrel or pilot to form a tube or long cup.

  • HOOKE'S LAW

Stress is proportional to strain. The law holds only up to the proportional limit.

  • HOOPES PROCESS

An electrolytic refining process for aluminum, using three liquid layers in the reduction cell.

  • HORIZONTAL-POSITION WELDING

(1) Making a fillet weld on the upper side of the intersection of a vertical surface and a horizontal surface. (2) Making a horizontal groove weld on a vertical surface.

  • HORN

In a resistance welding machine, a cylindrical arm or beam that transmits the electrode pressure and usually conducts the welding current.

  • HORN PRESS

A mechanical press equipped with or arranged for a cantilever block or horn that acts as the die or support for the die, used in forming, piercing, setting down, or riveting hollow cylinders and odd-shaped work.

  • HORN SPACING

The distance between adjacent surfaces of the horns of a resistance welding machine.

  • HOT BAND (HOT.ROLLED STEEL)

A coil of steel rolled on a hot-strip mill (hot-rolled steel). It can be sold in this form to customers or further processed into other finished products

  • HOT BED

An area adjacent to the runout table where hot rolled metal is placed to cool. Sometimes called the cooling table.

  • HOT BRIQUETTED IRON (HBI)

Direct reduced iron that has been processed into briquettes. Instead of using a blast furnace, the oxygen is removed from the ore using natural gas and results in a substance that is 90percent-92percent iron. Because DRI may spontaneously combust during transportation, HBI is preferred when the metallic material must be stored or moved

  • HOT CHAMBER MACHINE

A die casting machine in which the metal chamber under pressure is immersed in the molten metal in a furnace. The chamber is sometimes called a gooseneck and the machine, a gooseneck machine.

  • HOT COLD WORKING

(1) A high-temperature thermomechanical treatment consisting of deforming a metal above its transformation temperature and cooling fast enough to preserve some or all of the deformed structure. (2) A general term synonymous with warm working.

  • HOT DIP COATING

A metallic coating obtained by dipping the basis metal into a molten metal.

  • HOT END

The section of a steelmaking complex from the furnace up to, but not including, the hot-strip mill

  • HOT FORMING

See hot working.

  • HOT ISOSTATIC PRESSING

A process for simultaneously heating and forming a powder metallurgy compact in which metal powder, contained in a sealed flexible mold, is subjected to equal pressure from all directions at a temperature high enough for sintering to take place.

  • HOT ISOSTATIC PRESSURE WELDING

A diffusion-welding method that produces coalescence of materials by heating and applying hot inert gas under pressure.

  • HOT METAL

The name for the molten iron produced in a blast furnace. It proceeds to the basic oxygen furnace in molten form or is cast as pig iron

  • HOT MILL

A production line or facility for hot rolling metals.

  • HOT PRESS FORGING

Plastically deforming metals between dies in presses at temperatures high enough to avoid strain hardening.

  • HOT PRESSING

Forming a powder metallurgy compact at a temperature high enough to have concurrent sintering.

  • HOT PRESSURE WELDING

A solid state welding process that produces coalescence materials with heat and application of pressure sufficient to produce macrodeformation of the base material. Vacuum or other shielding media may be used. See also forge welding and diffusion welding.

  • HOT QUENCHING

An imprecise term used to cover a variety of quenching procedures in which a quenching medium is maintained at a prescribed temperature above 70 �C(160 �F).

  • HOT ROD

Same as wire rod.

  • HOT SHORTNESS

A tendency for some alloys to separate along grain boundaries when stressed or deformed at temperatures near the melting point. Hot shortness is caused by a low melting constituent, often present only in minute amounts, that is segregated at grain boundaries.

  • HOT TEAR

A fracture formed in a metal during solidification because of hindered contraction. Compare with hot crack.

  • HOT TOP

(1) A reservoir, thermally insulated or heated, to hold molten metal on top of a mold to feed the ingot or casting as it contracts on solidifying to avoid having pipe or voids. See accompanying sketch. (2) A refractory-lined steel or iron casting that is inserted into the tip of the mold and is supported at various heights to feed the ingot as it solidifies.

  • HOT TRIMMING

Removing flash or excess metal from a hot part (such as a forging) in a trimming press.

  • HOT WORKING

Deforming metal plastically at such a temperature and strain rate that recrystallization takes place simultaneously with the deformation, thus avoiding any strain hardening.

  • HOT-DIPPED

Steel is run through a molten zinc coating bath, followed by an air stream "wipe" that controls the thickness of the zinc finish

  • HOT-STRIP MILL

A rolling mill of several stands of rolls that converts slabs into hot-rolled coils. I hot-strip mill squeezes slabs, which can range in thickness from 2-10 inches, depending on the type of continuous caster, between horizontal rolls with a progressively smaller space between them (while vertical rolls govern the width) produce a coil of flat-rolled steel about a quarter-inch in thickness and a quarter n in length

  • HUBBING

Producing die cavities by pressing a male master plug, known as a hub, into a block of metal.

  • HULL CELL

A special electrodeposition cell giving a range of known current densities for test work.

  • HUMIDITY TEST

A corrosion test involving exposure of specimens at controlled levels of humidity and temperature. Contrast with salt-fog test.

  • HYDRAULIC (PANCAKE CYLINDER)

This modern system uses fluid pressure to rapidly adjust the roll spacing several times per second. These minute, instantaneous adjustments allow for superior gauge tracking and higher-quality products

  • HYDRAULIC PRESS

A press in which fluid pressure is used to actuate and control the ram.

  • HYDRIDE DESCALING

Descaling by action of a hydride in a fused alkali.

  • HYDROFORMING

A forming process in which a tube is placed into a forming die. The tube is then formed to the shape of the die through the application of internal water pressure. The hydroforming process allows for severe shape deformation, making it ideal for automotive structural parts such as engine cradles, radiator supports and body rails Various shaped and sized holes can be punched in the tube almost anywhere during the process

  • HYDROGEN BRAZING

A term sometimes used to denote brazing in a hydrogen containing atmosphere, usually in furnace; use of the appropriate process name is preferred.

  • HYDROGEN DAMAGE

A general term for the embrittlement, cracking, blistering and hydride formation that car occur when hydrogen is present in some metals.

  • HYDROGEN EMBRITTLEMENT

A conditiom of low ductility in metals resulting from the absorption of hydrogen.

  • HYDROGEN LOSS

The loss in weight ofmetal powder or of a compact caused by heating a representative sample for a specified time and temperature in a hydrogen atmosphere. Broadly, measure of the oxygen content of the sample, when applied to material' containing only such oxides as reducible with hydrogen and no hydride-forming element.

  • HYDROGEN OVERVOLTAGE (IN ELECTROPLATING)

Overvoltage associated with the liberation of hydrogen.

  • HYDROGEN-REDUCED POWDER

Metal powder produced by the hydrogen reaction of a compound.

  • HYDROMETALLURGY

Industrial winning or refining of metals using water or an aqueous solution.

  • HYDROSTATIC TENSION

Three equal and mutually perpendicular tensile stresses.

  • HYL I, HYL III

Processes for producing DRI and HBI developed by Hylsa. The processes reduce iron ore lump or pellets with reformed natural gas in a vertical shaft furnace. The HYL I process uses four fixed-bed reactors; HYL III uses a single-shaft furnace

  • HYPEREUTECTIC ALLOY

In an alloy system exhibiting a eutectic, any alloy whose composition has an excess of alloying element compared to the eutectic composition, and whose equilibrium microstructure contain some eutectic structure.

  • HYPEREUTECTOID ALLOY

In an alloy system exhibiting a eutectoid, any alloy whose composition has an excess of alloying element compared to the eutectoid composition, and whose equilibrium microstructure contain some eutectoid structure.

  • HYPOCUTECTIC ALLOY

In an alloy system exhibiting a eutectic, any alloy whose composition has an excess of base metal compared to the eutectic composition, and whose equilibrium microstructure contains some eutectoid structure.

  • HYPOEUTECTOID ALLOY

In an alloy System exhibiting a eutectoid, any alloy whose composition has an excess of base metal compared to the eutectoid composition, and whose equilibrium microstructure contains some eutectoid structure.

  • HYSTERESIS, MAGNETIC

The lag of the magnetization of an iron or steel specimen behind any cyclic variation of the applied magnetizing field.

  • I-BEAMS

Structural sections on which the flanges are tapered and are typically not as long as the flanges on wide-flange beams. The flanges are thicker at the cross sections and thinner at the toes of the flanges. They are produced with depths of 3-24 inches

  • IDIOMORPHIC CRYSTAL

An individual crystal that has grown without restraint so that the habit planes are clearly developed. Compare with allotriomorphic crystal.

  • IMMERSION CLEANING

Cleaning where the work is immersed in a liquid solution.

  • IMMERSION COATING

A coating produced in a solution by chemical or electrochemical action without the use of external current.

  • IMMERSION PLATING

Depositing a metallic coating on a metal immersed in a liquid solution, without the aid of an external electric current. Also called dip plating.

  • IMPACT ENERGY

The amount of energy required to fracture a material, usually measured by means of an Izod or Charpy test. The type of specimen and test conditions affect the values and therefore should be specified.

  • IMPACT EXTRUSION

See extrusion.

  • IMPACT LINE

A blemish on a drawn sheet-metal part caused by a slight change in metal thickness. The mark is called an impact line when it results from impact of the punch on the blank, it is called a recoil line when it results from transfer of the blank from the die to the punch during forming, or from a reaction to the blank being pulled sharply through the draw ring.

  • IMPACT STRENGTH

Same as impact energy.

  • IMPACT TEST

A test to determine the behavior of materials when subjected to high rates of loading, usually in bending, tension or torsion. The quantity measured is the energy absorbed in breaking the specimen by a single blow, as in the Charpy or Izod tests.

  • IMPERFECTION

(1) When referring to the physical condition of a part or metal product, any departure of a quality characteristic from its intended level or state. The existence of an imperfection does not imply nonconformance, nor does it have any implication as to the usability of a product or service. An imperfection must be rated on a scale of severity, in accordance with applicable specifications, to establish whether or not the part or metal product is of acceptable quality. (2) Generally, any departure from an ideal design, state or condition. (3) In crystallography, any deviation from an ideal space lattice.

  • IMPORT ADMINISTRATION

Import Administration, within the International Trade Administration of the Department of Commerce, enforces laws and agreements to protect U.S. businesses from unfair competition within the United States resulting from unfair pricing by foreign companies and unfair subsidies to foreign companies by their governments

  • IMPREGNATION

(1) The treatment of porous castings with a sealing medium to stop pressure leaks. (2) The process of filling the pores of a sintered compact, usually with a liquid such as a lubricant. (3) The process of mixing particles of a nonmetallic substance in a matrix of metal powder, as in diamond-impregnated tools.

  • IMPRESSION DIE FORGING

A forging that is formed to the required shape and size by machined impressions in specially prepared dies that exert three-dimensional control on the workpiece.

  • IMPURITIES

Elements or compounds whose presence in a material is undesired.

  • INCLINABLE PRESS

A press that can be inclined to facilitate handling of the formed parts. See open-back inclinable press.

  • INCLUSIONS

Particles of foreign material in a metallic matrix. The particles are usually compounds (such as oxides, sulfides or silicates), but may be of any substance that is foreign to (and essentially insoluble in) the matrix.

  • INDENTATION

In a spot, seam or projection weld, the depression on the exterior surface of the base metal.

  • INDENTATION HARDNESS

The resistance of a material to indentation. This is the usual type of hardness test, in which a pointed or rounded indenter is pressed into a surface under a substantially static load.

  • INDICATION

In inspection, a response to a nondestructive stimulus that implies the presence of an imperfection. The indication must be interpreted to determine if (a) it is a true indication or a false indication and (b) whether or not a true indication represents an unacceptable deviation.

  • INDICATOR

A substance that, through some visible change such as color, indicates the condition of a solution or other material as to the presence of free acid, alkali or other substance.

  • INDIRECT EXTRUSION

See extrusion.

  • INDIRECT-ARC FURNACE

An electric-arc furnace in which the metallic charge is not one of the poles of the arc.

  • INDUCTION BRAZING

Brazing in which the required heat is generated by subjecting the workpiece to electromagnetic induction.

  • INDUCTION FURNACE

An ac electric furnace in which the primary conductor is coiled and generates, by electromagnetic induction, a secondary current that develops heat within the metal charge.

  • INDUCTION HARDENING

A surface-hardening process in which only the surface layer of a suitable ferrous workpiece is heated by electromagnetic induction to above the upper critical temperature and immediately quenched.

  • INDUCTION HEATING

Heating by combined electrical resistance and hysteresis losses induced by subjecting a metal to the varying magnetic field surrounding a coil carrying alternating current.

  • INDUCTION MELTING

Melting in an induction furnace.

  • INDUCTION WELDING

Welding in which the required heat is generated by subjecting the workpiece to electromagnetic induction.

  • INERT ANODE

An anode that is insoluble in the electrolyte under the conditions prevailing in the electrolysis.

  • INFILTRATION

The process of filling the pores of a sintered or unsintered powder metallurgy compact with a metal or alloy of lower melting point.

  • INGOT

A casting of simple shape, suitable for hot working or remelting.

  • INGOT

A form of semi-finished steel. Liquid steel is teemed (poured) into molds, where it slowly solidifies. Once the steel is solid, the mold is stripped, and the 25- to 30-for ingots are then ready for subsequent rolling or forging

  • INGOT IRON

Commercially pure iron.

  • INHIBITOR

A substance that retards some specific chemical reaction. Pickling inhibitors retard the dissolution of metal without hindering the removal of scale from steel.

  • INMETCO

WHAT. Inmetco is a coal-based process similar to FASTMET that uses iron oxide fines and pulverized coal to produce a scrap substitute. Mill scale and flue dust, inexpensive byproducts of steelmaking, can be mixed with the iron oxide fines. Inmetco, unlike other direct reduction products, is intended to be hot charged into an EAF, with attendant energy savings. HOW. The process includes three steps. First, iron oxide fines, pulverized coal and binder are formed into pellets. Second, the pellets, two to three layers deep, are heated in a gas-fired rotary hearth furnace for 15-20 minutes to produce sponge iron. Subsequently, the iron must be desulfurized. The coal in the pellets provides much of the energy required in the second phase

  • INOCULATION

The addition of a material to molten metal to form nuclei for crystallization.

  • INSERT DIE

A relatively small die containing part or all of the impression of a forging, and which is fastened to a master die block.

  • INTEGRATED MILLS

These facilities make steel by processing iron ore and other raw materials in blast furnaces. Technically, only the hot end differentiates integrated mills from mini-mills. However, the differing technological approaches to molten steel imply different scale efficiencies and, therefore, separate management styles, labor relations, and product markets. Nearly all domestic integrated mills specialize in flat-rolled steel or plate

  • INTERCEPT METHOD

A quantitative metallographic technique in which the desired quantity (such as grain size or amount of precipitate) is expressed as the number of times per unit length a straight line on a metallographic image crosses particles of the feature being measured.

  • INTERCOMMUNICATING POROSITY

In a sintered powder metallurgy compact, a type of porosity in which individual pores are connected in such a way that a fluid may pass from one pore to another throughout the entire compact.

  • INTERCRYSTALLINE

Between the crystals, or grains, of a metal.

  • INTERDENDRITIC CORROSION

Corrosive attack that progresses preferentially along interdendritic paths. This type of attack results from local differences in composition, such as coring commonly encountered in alloy castings.

  • INTERFACE

A surface that forms the boundary between phases or systems.

  • INTERFACIAL TENSION

The contractile force of an interface between two phases.

  • INTERFERENCE FIT

Any of various classes of fit between mating parts where there is nominally a negative or zero allowance between the parts, and there is either part interference or no gap when the mating parts are made to the respective extremes of individual tolerances that ensure the tightest fit between the parts. Contrast with clearance fit.

  • INTERGRANULAR CORROSION

Corrosion occurring preferentially at grain boundaries, usually with slight or negligible attack on the adjacent grains. See also interdendritic corrosion.

  • INTERMEDIATE ANNEALING

Annealing wrought metals at one or more stages during manufacture and before final treatment.

  • INTERMEDIATE ELECTRODE

Same as bipolar electrode.

  • INTERMEDIATE PHASE

In an alloy or a chemical system, a distinguishable homogeneous phase whose composition range does not extend to any of the pure components of the system.

  • INTERMETALLIC COMPOUND

An intermediate phase in an alloy system, having a narrow range of homogeneity and relatively simple stoichiometric proportions; the nature of the atomic binding can be of various types, ranging from metallic to ionic.

  • INTERMITTENT WELD

A weld in which the continuity is broken by recurring unwelded spaces.

  • INTERNAL FRICTION

The conversion of energy into heat by a material subjected to fluctuating stress. In free vibration, the internal friction is measured by the logarithmic decrement.

  • INTERNAL OXIDATION

Preferential in situ oxidation of certain components or phases within the bulk of a solid alloy accomplished by diffusion of oxygen into the body; a form of subsurface corrosion.

  • INTERNAL STRESS

See preferred term, residual stress.

  • INTERPASS TEMPERATURE

In a multipass weld, the lowest temperature of a pass before the succeeding one is commenced.

  • INTERRUPTED AGING

Aging at two or more temperatures, by steps, and cooling to room temperature after each step. See aging, and compare with progressive aging and step aging.

  • INTERRUPTED QUENCHING

A quenching procedure in which the workpiece is removed from the first quench at a temperature substantially higher than that of the quenchant and is then subjected to a second quenching system having a different cooling rate than the first.

  • INTERRUPTED-CURRENT PLATING

Plating in which the flow of current is discontinued for periodic short intervals to decrease anode polarization and elevate the critical current density. It is most commonly used in cyanide copper plating.

  • INTERSTITIAL FREE STEEL

A recently developed sheet steel product with very low carbon levels that is used primarily in automotive deep-drawing applications. Interstitial Free Steel's improved ductility (drawing ability) is made possible by vacuum degassing

  • INTERSTITIAL SOLID SOLUTION

A solid solution in which the solute atoms occupy positions that do not correspond to lattice points of the solvent. Contrast with substitutional solid solution.

  • INTRACRYSTALLINE

Within or across the crystals or grains of a metal; same as transcrystalline and transgranular.

  • INVERSE CHILL

A condition in an iron casting in which the interior is chilled or white iron while the surfaces are mottled or contain free graphite.

  • INVERSE SEGREGATION

Segregation in cast metal in which an excess of lower-melting constituents occurs in the earlier freezing portions, apparently the result of liquid metal entering cavities developed in the earliersolidified metal.

  • INVESTMENT CASTING

(1) Casting metal into a mold produced by surrounding (investing) an expendable pattern with a refractory slurry that sets at room temperature after which the wax, plastic or frozen mercury pattern is removed through the use of heat. Also called precision casting, or lost-wax process. (2) A part made by the investment casting process.

  • INVESTMENT COMPOUND

A mixture of a graded refractory filler, a binder and a liquid vehicle, used to make molds for investment casting.

  • ION

An atom, or group of atoms, that has gained or lost one or more outer electrons and thus carries an electric charge. Positive ions, or cations, are deficient in outer electrons. Negative ions, or anions, have an excess of outer electrons.

  • ION EXCHANGE

The reversible interchange of ions between a liquid and solid, with no substantial structural changes in the solid.

  • IONIC BOND

A bond between two or more atoms that is the result of electrostatic attractive forces between positively and negatively charged ions.

  • IONIC CRYSTAL

A crystal in which atomic bonds are ionic bonds. This type of atomic linkage, also known as (hetero) polar bonding, is characteristic of many compounds (sodium chloride, for instance).

  • IONIZATION CHAMBER

An enclosure containing two or more electrodes surrounded by a gas capable of conducting an electric current when it is ionized by x-rays or other ionizing rays. It is commonly used for measuring intensity of such radiation.

  • IRON CARBIDE

One of several substitutes for high-quality, low-residual scrap for use in electric furnace steelmaking. Iron carbide producers use natural gas to reduce iron ore to iron carbide

  • IRON CASTING

A part made of cast iron.

  • IRON ORE

Mineral containing enough iron to be a commercially viable source of the element for use in steelmaking. Except for fragments of meteorites found on Earth, iron is not a free element; instead, it is trapped in the earth's crust in its oxidized form

  • IRONING

Thinning the walls of hollow articles by drawing them between a punch and a die.

  • IRON-POWDER ELECTRODE

A welding electrode with a covering containing up to about 50 percent iron powder, some of which becomes part of the deposit.

  • IRRADIATION

The exposure of a material in a field of radiation; the cumulative exposure.

  • ISOSTATIC PRESSING

A process for forming a powder metallurgy compact by applying pressure equally from all directions to metal powder contained in a sealed flexible mold. See also hot isostatic pressing.

  • ISOTHERMAL ANNEALING

Austenitizing a ferrous alloy and then cooling to and holding at a temperature at which austenite transforms to a relatively soft ferrite carbide aggregate.

  • ISOTHERMAL TRANSFORMATION

A change in phase that takes place at a constant temperature. The time required for transformation to be completed, and in some instances the time delay before transformation begins, depends on the amount of supercooling below (or superheating above) the equilibrium temperature for the same transformation.

  • ISOTOPE

One of several different nuclides of an element having the same number of protons in their nuclei and therefore the same atomic number, but differing in the number of neutrons and therefore in atomic weight.

  • ISOTROPY

Quality of having identical properties in all directions.

  • IZOD TEST

A pendulum-type singleblow impact test in which the specimen, usually notched, is fixed at one end and broken by a falling pendulum. The energy absorbed, as measured by the subsequent rise of the pendulum, is a measure of impact strength or notch toughness. Contrast with Charpy test.

  • JIG

A device to hold a workpiece in place and simultaneously guide the tool in a cutting operation.

  • JIG BORING

Boring with a single-point tool where the work is positioned upon a table that can be located so as to bring any desired part of the work under the tool. Thus, holes can be accurately spaced. This type of boring can be done on milling machines or jig borers.

  • JIG GRINDING

Analogous to jig boring, where the holes are ground rather than machined.

  • JOGGLE

An offset in a flat plane consisting of two parallel bends in opposite directions by the same angle.

  • JOINT

The location where two or more members are to be or have been fastened together mechanically or by brazing or welding.

  • JOINT EFFICIENCY

The strength of a welded joint expressed as a percentage of the strength of the unwelded base metal.

  • JOINT PENETRATION

The minimum depth a groove or flange weld extends from its face into the joint, exclusive of reinforcement. Joint penetration may include root penetration.

  • JOMINY TEST

See end-quench hardenability test.

  • KEEL BLOCK

A standard test casting, for steel and other high-shrinkage alloys, consisting of a rectangular bar that resembles the keel of a boat, attached to the bottom of a large riser, or shrinkhead. Keel blocks that have only one bar are often called Y-blocks; keel blocks having two bars, double keel blocks. Test specimens are machined from the rectangular bar, and the shrinkhead is discarded.

  • KERF

The space that was occupied by the material removed during cutting.

  • KEYHOLE SPECIMEN

A type of specimen containing a hole-and-slot notch, shaped like a keyhole, usually used in impact bend tests. See Charpy and Izod tests.

  • KILLED STEEL

Steel treated with a strong deoxidizing agent such as silicon or aluminum in order to reduce the oxygen content to such a level that no reaction occurs between carbon and oxygen during solidification.

  • KILN

A large furnace used for baking, drying or burning fire brick or refractories, or for calcining ores or other substances.

  • KISH

Free graphite that forms in molten hypereutectic cast iron as it cools. In castings, the Kish may segregate toward the cope surface, where it lodges at or immediately beneath the casting surface.

  • KNOCKOUT

(1) A mechanism for freeing formed parts from a die used for stamping, blanking, drawing, forging or heading operations. (2) A partly pierced hole in a sheet metal part, where the slug remains in the hole and can be forced out by hand if a hole actually is needed. (3) Removing sand cores from a casting. (4) Jarring an investment casting mold to remove the casting and investment from the flask.

  • KNOOP HARDNESS

Microhardness determined from the resistance of metal to indentation by a pyramidal diamond indenter, having edge angles of 172� 30' and 130�, making a rhombohedral impression with one long and one short diagonal.

  • KNUCKLE-JOINT PRESS

A heavy shortstroke press in which the slide is directly actuated by a single toggle joint that is opened and closed by a connection and crank. It is used for embossing, coining, sizing, heading, swaying and extruding.

  • KNURLING

Impressing a design into a metallic surface, usually by means of small, hard rollers that carry the corresponding design on their surfaces.

  • KROLL PROCESS

A process for the production of metallic titanium by the reduction of titanium tetrachloride with a more active metal such as magnesium, yielding titanium as granules or powder.

  • LADLE

A receptacle used for transferring and pouring molten metal.

  • LADLE METALLURGY FURNACE (LMF)

An intermediate steel processing unit that further refines the chemistry and temperature of molten steel while it is still in the ladle. The ladle metallurgy step comes after the steel is melted and refined in the electric arc or basic oxygen furnace, but before the steel is sent to the continuous caster

  • LAMINATE

(1) A composite metal, usually in the form of sheet or bar, composed of two or more metal layers so bonded that the composite metal forms a structural member. (2) To form a metallic product of two or more bonded layers.

  • LAMINATION

(1) A type of discontinuity with separation or weakness generally aligned parallel to the worked surface of a metal. May be the result of pipe, blisters, seams, inclusions or segregation elongated and made directional by working. Laminations may also occur in metal-powder compacts. (2) In electrical products such as motors, a blanked piece of electrical sheet that is stacked up with several other identical pieces to make a stator or rotor.

  • LAP

A surface imperfection, appearing as a seam, caused by folding over hot metal, fins or sharp corners and then rolling or forging them into the surface, but not welding them.

  • LAP JOINT

A joint made with two overlapping members

  • LAPPING

Finishing surfaces by abrasion with an object, usually made of copper, lead, cast iron or closegrained wood, having very fine abrasive particles rolled into its surface.

  • LASER

A device that emits a concentrated beam of electromagnetic radiation (light). Laser beams are used in metalworking to melt, cut or weld metals; in less concentrated form they are sometimes used to inspect metal parts.

  • LASER-BEAM CUTTING

A cutting process that severs materials with the heat obtained by directing a beam from a laser against a metal surface. The process can be used with or without an externally supplied shielding gas.

  • LASER-BEAM MACHINING

Removing material by melting and vaporizing the workpiece at the point of impingement of a highly focused beam of coherent monochromatic light (a laser beam).

  • LASER-BEAM WELDING

A welding process that joins metal parts using the heat obtained by directing a beam from a laser onto the weld joint.

  • LATENT HEAT

Thermal energy absorbed or released when a substance undergoes a phase change.

  • LATERAL EXTRUSION

An operation in which the product is extruded sideways through an orifice in the container wall.

  • LATTICE CONSTANT

See lattice parameter.

  • LATTICE PARAMETER

The length of any side of a unit cell of a given crystal structure; if the lengths are unequal, all unequal lengths must be given.

  • LAY

Direction of predominant surface pattern remaining after cutting, grinding, lapping or other processing.

  • LEACHING

Extracting an element or compound from a solid alloy or mixture by preferential dissolution in a suitable liquid.

  • LEAD

(1) The axial advance of a helix in one complete turn. (2) The slight bevel at the outer end of a face cutting edge of a face mill.

  • LEAD ANGLE

In cutting tools, the helix angle of the flutes.

  • LEAD BURNING

A misnomer for the welding of lead.

  • LEAKAGE FIELD

The magnetic field that leaves or enters a magnetized part at a magnetic pole.

  • LEDEBURITE

The eutectic of the ironcarbon system, the constituents being austenite and cementite. The austenite decomposes into ferrite and cementite on cooling below the Ar1.

  • LEFT-HAND CUTTING TOOL

A cutter all of whose flutes twist away in a counterclockwise direction when viewed from either end.

  • LEG OF A FILLET WELD

(1) Actual: The distance from the root of the joint to the toe of a fillet weld. See accompanying sketch and sketches of concave fillet weld and convex fillet weld.

  • LEGACY COSTS

Any costs that are associated with prior operations. Employee liabilities (pensions and health care benefits) and environmental cleanup costs usually are included under this moniker

  • LEVELER LINES

Lines on sheet or strip running transverse to the direction of roller leveling, may be seen on stoning or light sanding after leveling (but before drawing). Usually can be removed by moderate stretching.

  • LEVELING

Flattening of rolled sheet, strip or plate by reducing or eliminating distortions. See stretcher leveling and roller leveling.

  • LEVELING ACTION

Action exhibited by a plating solution to give a plate smoother than the basis metal.

  • LEVELING LINE

A process to flatten any shape deficiencies (wavy edges and buckles) in the sheet, prior to final shipment. Most cold-rolled sheet initially has a crowned cross-section that, if such a shape is undesirable to the customer, must be flattened in the levering line

  • LEVIGATION

(1) Separating fine powder from coarser material by forming a suspension of the fine material in a liquid. (2) A means of classifying a material as to particle size by the rate of settling from a suspension.

  • LEVITATION MELTING

An induction melting process in which the metal being melted is suspended by the electromagnetic field and is not in contact with a container.

  • LIFE CYCLE COSTING

An accounting method of costing where expenses are allocated over the life of the product. Life cycle costs are often lower for stainless steel than for alternatives despite a higher initial outlay, because stainless products generally last longer and require little maintenance

  • LIGHT DRAWN

An imprecise term applied to drawn products, such as wire and tubing, that indicates a lesser amount of cold reduction than for hard drawn products.

  • LIGHT GAUGE STEEL

Very thin steel sheet that has been temper-rolled or passed through a cold mill. Light gauge steel normally is plated with tin or chrome for use in food containers

  • LIGHT METAL

One of the low-density metals such as aluminum, magnesium, titanium, beryllium or their alloys.

  • LIGHTLY COATED ELECTRODE

A fillermetal electrode used in arc welding, consisting of a metal wire with a light coating, usually of metal oxides and silicates, applied subsequent to the drawing operation primarily for stabilizing the arc. Contrast with covered electrode.

  • LIMITING CURRENT DENSITY

The maximum current density that can be used to get a desired electrode reaction without undue interference such as may come from polarization.

  • LINE PIPE

Pipe used in the surface transmission of oil, natural gas and other fluids

  • LINEAGE STRUCTURE

(1) Deviations from perfect alignment of parallel arms of a columnar dendrite as a result of interdendritic shrinkage during solidification from a liquid. This type of deviation may vary in orientation from one area to another from a few minutes to as much as two degrees of arc. (2) A type of substructure consisting of elongated subgrains.

  • LINEAR ELASTIC FRACTURE MECHANICS

A method of fracture analysis that can determine the stress (or load) required to induce fracture instability in a structure containing a crack-like flaw of known size and shape. See stress-intensity factor.

  • LINEAR STRAIN

See strain.

  • LINER

(1) The slab of coating metal that is placed on the core alloy and is subsequently rolled down to clad sheet as a composite. (2) In extrusion, a removable alloy steel cylindrical chamber, having an outside longitudinal taper firmly positioned in the container or main body of the press, into which the billet is placed for extrusion.

  • LIP ANGLE

(1) For a milling cutter, the included angle between a tooth face and a relieved land. (2) Defined by sketch accompanying single-point tool.

  • LIQUATION

The partial melting of an alloy, usually as a result of coring or other compositional heterogeneities.

  • LIQUATION TEMPERATURE

The lowest temperature at which partial melting can occur in an alloy that exhibits the greatest possible degree of segregation.

  • LIQUID HONING

Producing a finely polished finish by directing an air ejected chemical emulsion containing fine abrasives against the surface to be finished.

  • LIQUID PENETRANT INSPECTION

A type of nondestructive inspection that locates discontinuities that are open to the surface of a metal by first allowing a penetrating dye or fluorescent liquid to infiltrate the discontinuity, removing the excess penetrant, and then applying a developing agent that causes the penetrant to seep back out of the discontinuity and register as an indication. Liquid penetrant inspection is suitable for both ferrous and nonferrous materials, but is limited to the detection of open surface discontinuities in nonporous solids.

  • LIQUID PHASE SINTERING

Sintering a powder metallurgy compact under conditions that maintain a liquid metallic phase within the compact during all or part of the sintering schedule. The liquid phase may be derived from a component of the green compact or may be infiltrated into the compact from an outside source.

  • LIQUID SHRINKAGE

See casting shrinkage.

  • LIQUIDUS

In a constitution or equilibrium diagram, the locus of points representing the temperatures at which the various compositions in the system begin to freeze on cooling or finish melting on heating. See also solidus.

  • LIQUOR FINISH

A smooth, bright finish characteristic of wet-drawn wire. Formerly produced by using liquor from fermented grain mash as a drawing lubricant.

  • LIVE CENTER

A lathe or grinder center that holds, yet rotates with, the work. It is used in either the headstock or tailstock of a machine to prevent wear and reduce the driving torque.

  • LOADING

(1) In cutting, building up of a cutting tool back of the cutting edge by undesired adherence of material removed from the work. (2) In grinding, filling the pores of a grinding wheel with material from the work, usually resulting in a decrease in production and quality of finish. (3) In powder metallurgy, filling of the die cavity with powder.

  • LOAM

A molding material consisting of sand, silt and clay, used over brickwork or other structural backup material for making massive castings, usually of iron or steel.

  • LOCAL ACTION

Corrosion due to the action of "local cells"; that is, galvanic cells resulting from inhomogeneities between adjacent areas on a metal surface exposed to an electrolyte.

  • LOCAL CELL

A galvanic cell resulting from inhomogeneities between areas on a metal surface in an electrolyte. The inhomogeneities may be of physical or chemical nature in either the metal or its environment.

  • LOCAL CURRENT DENSITY

Current density at a point or on a small area.

  • LOCALIZED PRECIPITATION

Precipitation from a supersaturated solid solution similar to continuous precipitation, except that the precipitate particles form at preferred locations, such as along slip planes, grain boundaries or incoherent twin boundaries.

  • LOCATIONAL FIT

A clearance or interference fit intended for locating mating parts.

  • LONG PRODUCTS

Classification of steel products that includes bar, rod and structural products, that are "long," rather than "flat''

  • LONGITUDINAL DIRECTION

The principal direction of flow in a worked metal.

  • LONGITUDINAL FIELD

A magnetic field that extends within a magnetized part from one or more poles to one or more other poles and that is completed through a path external to the part.

  • LOOPING MILL

An arrangement of hot rolling stands such that a hot bar, while it is being discharged from one stand, is fed into a second stand in the opposite direction.

  • LOST-WAX PROCESS

An investment casting process in which a wax pattern is used.

  • LOT

A finite quantity of a given product manufactured under production conditions that are considered uniform. Often used to describe a finite quantity of product submitted for inspection as a single group. For a bulk product (such as a chemical or powdered metal), the term "batch" is often used synonymously with lot.

  • LOW SHAFT FURNACE

A short shaft-type blast furnace used to produce pig iron and ferroalloys from low-grade ores using low-grade fuel. The air blast is often enriched with oxygen. It is also used for making a variety of other products such as alumina, cementmaking slags and ammonia synthesis gas.

  • LOW-CARBON STEEL

Steel with less than 0.005percent carbon is more ductile (malleable): It is capable being drawn out or rolled thin for use in automotive body applications. Carbon is removed from the steel bath through vacuum degassing

  • LOWER PUNCH

The lower part of a die, which forms the bottom of the die cavity and which may or may not move in relation to the die body usually movable in a forging die.

  • LOW-HYDROGEN ELECTRODE

A covered arc-welding electrode that provides an atmosphere around the arc and molten weld metal that is low in hydrogen.

  • LOW-RESIDUAL-PHOSPHORUS COPPER

Deoxidized copper with residual phosphorus present in amounts (usually 0.004 to 0.012percent) generally too small to decrease appreciably the electrical conductivity of the copper.

  • LUBRICANT

Any substance used to reduce friction between two surfaces in contact.

  • L�DERS LINES

Elongated surface markings or depressions caused by localized plastic deformation that results from discontinuous (inhomogeneous) yielding. Also known as L�ders bands, Hartmann lines, Piobert lines or stretcher strains.

  • LUSTER FINISH

A bright as-rolled finish, produced on ground rolls; it is suitable for decorative painting or plating, but usually must undergo additional surface preparation after forming.

  • LUTE

(1) A mixture of fireclay used to seal cracks between a crucible and its cover or between container and cover when heat is to be applied. (2) To seal with clay or other plastic material.

  • M SECTIONS (BANTAM BEAMSTM, JUNIOR BEAMATM)

Light footweight beams primarily used in the construction of pre-engineered housing. These beams are produced in lighter footweights, usually six to 10 per foot, than traditional structural products

  • MACHINABILITY

The relative ease of machining a metal.

  • MACHINABILITY INDEX

A relative measure of the machinability of an engineering material under specified standard conditions.

  • MACHINE FORGING

Forging performed in upsetters or horizontal forging machines.

  • MACHINE WELDING

Welding with equipment that performs under the continual observation and control of a welding operator. The equipment may or may not load and unload the work. Compare with automatic welding.

  • MACHINING

Removing material from a metal part, usually using a cutting tool, and usually using a power driven machine.

  • MACHINING ALLOWANCE

Finish allowance.

  • MACHINING STRESS

Residual stress caused by machining.

  • MACROETCHING

Etching a metal surface to accentuate gross structural details (such as grain flow, segregation, porosity or cracks) for observation by the unaided eye or at a magnification of ten diameters or less.

  • MACROGRAPH

A graphic reproduction of the surface of a prepared specimen at a magnification not exceeding ten diameters. When photographed, the reproduction is known as a photomacrograph.

  • MACROSCOPIC

Visible at magnifications up to ten diameters.

  • MACROSCOPIC STRESSES

Residual stresses that vary from tension to compression in a distance (presumably many times the grain size) that is comparable to the gage length in ordinary strain measurements, hence, detectable by x-ray or dissection methods.

  • MACROSHRINKAGE

Isolated, clustered or interconnected voids in a casting that are detectable macroscopically. Such voids are usually associated with abrupt changes in section size and are caused by a lack of adequate feeding to compensate for solidification shrinkage.

  • MACROSTRESS

Same as macroscopic stress.

  • MACROSTRUCTURE

The structure of metals as revealed by macroscopic examination of the etched surface of a polished specimen.

  • MAGNESITE WHEEL

A grinding wheel bonded with magnesium oxychloride.

  • MAGNETIC POLE

The area on a magnetized part at which the magnetic field leaves or enters the part. It is a point of maximum attraction in a magnet.

  • MAGNETIC SEPARATOR

A device used to separate magnetic from less magnetic or nonmagnetic materials. The crushed material is conveyed on a belt past a magnet.

  • MAGNETIC WRITING

In magnetic-particle inspection, a false indication caused by contact between a magnetized part and another piece of magnetic material.

  • MAGNETICALLY HARD ALLOY

A ferromagnetic alloy capable of being magnetized permanently because of its ability to retain induced magnetization and magnetic poles after removal of externally applied fields; an alloy with high coercive force. The name is based on the fact that the quality of the early permanent magnets was related to their hardness.

  • MAGNETICALLY SOFT ALLOY

A ferromagnetic alloy that becomes magnetized readily upon application of a field and that returns to practically a nonmagnetic condition when the field is removed; an alloy with the properties of high magnetic permeability, low coercive force and low magnetic hysteresis loss.

  • MAGNETIC-ANALYSIS INSPECTION

A nondestructive method of inspection to determine the existence of variations in magnetic flux in ferromagnetic materials of constant cross section, such as might be caused by discontinuities and variations in hardness. The variations are usually indicated by a change in pattern on an oscilloscopic screen.

  • MAGNETIC-PARTICLE INSPECTION

A nondestructive method of inspection for determining the existence and extent of surface cracks and similar imperfections in ferromagnetic materials. Finely divided magnetic particles, applied to the magnetized part, are attracted to and outline the pattern of any magnetic-leakage fields created by discontinuities.

  • MAGNETIZING FORCE

A force field, resulting from the flow of electric currents or from magnetized bodies, that produces magnetic induction.

  • MAGNETOSTRICTION

The characteristic of a material that is manifest by strain when it is subjected to a magnetic field; or the inverse. Some ironnickel alloys expand; pure nickel contracts.

  • MALLEABILITY

The characteristic of metals that permits plastic deformation in compression without rupture.

  • MALLEABLE CAST IRON

A cast iron made by a prolonged anneal of white cast iron in which decarburization or graphitization, or both, take place to eliminate some or all of the cementite. The graphite is in the form of temper carbon. If decarburization is the predominant reaction, the product will have a light fracture, hence, "whiteheart malleable"; otherwise, the fracture will be dark, hence "blackheart malleable". Ferritic malleable has a predominantly ferritic matrix; pearlitic malleable may contain pearlite, spheroidite or tempered martensite depending on heat treatment and desired hardness.

  • MALLEABLIZING

Annealing white cast iron in such a way that some or all of the combined carbon is transformed to graphite or, in some instances, part of the carbon is removed completely.

  • MAN HOURS PER TON

This is a measure of labor efficiency-the ratio of total hours worked by steel employees to the tons shipped for a given period of time. Changes in the in - level and work that is contracted out will affect the reported measurement

  • MANDREL

(1) A blunt ended tool or rod used to retain the cavity in hollow metal products during working. (2) A metal bar around which other metal may be cast, bent, formed or shaped. (3) A shaft or bar for holding work to be machined. (4) A form, such as a mold or matrix, used as a cathode in electroforming.

  • MANNESMANN MILL

Mill used in Mannesmann process.

  • MANNESMANN PROCESS

A process used for piercing tube billets in making seamless tubing. The billet is rotated between two heavy rolls mounted at an angle and is forced over a fixed mandrel.

  • MANUAL WELDING

Welding wherein the entire welding operation is performed and controlled by hand.

  • MARAGING

A precipitation-hardening treatment applied to a special group of iron-base alloys to precipitate one or more intermetallic compounds in a matrix of essentially carbon-free martensite. NOTE: The first developed series of maraging steels contained, in addition to iron, more than 10 percent nickel and one or more supplemental hardening elements. In this series, aging is done at 480 �C (900 �F).

  • MARQUENCHING

See martempering.

  • MARTEMPERING

(1) A hardening procedure in which an austenitized ferrous workpiece is quenched into an appropriate medium whose temperature is maintained substantially at the Ms of the workpiece, held in the medium until its temperature is uniform throughout - but not long enough to permit bainite to form - and then cooled in air. The treatment is frequently followed by tempering. (2) When the process is applied to carburized material, the controlling MB temperature is that of the case. This variation of the process is frequently called marquenching.

  • MARTENSITE

A generic term for microstructures formed by diffusionless phase transformation in which the parent and product phases have a specific crystallographic relationship. Martensite is characterized by an acicular pattern in the microstructure in both ferrous and nonferrous alloys. In alloys where the solute atoms occupy interstitial positions in the martensitic lattice (such as carbon in iron), the structure is hard and highly strained; but where the solute atoms occupy substitutional positions (such as nickel in iron), the martensite is soft and ductile. The amount of high temperature phase that transforms to martensite on cooling depends to a large extent on the lowest temperature attained, there being a rather distinct beginning temperature (Ms) and a temperature at which the transformation is essentially complete (Mf).

  • MARTENSITE RANGE

The temperature interval between Ma and Mf.

  • MARTENSITIC

Small category of stainless steel characterized by the use of heat treatment for hardening and strengthening. Martensitic stainless steels are plain chromium with no significant nickel content. They are utilized in equipment for the chemical and oil industries and in surgical instruments. The most popular martensitic stainless steel is type 410 (a grade appropriate for non-severe corrosion environments requiring high strength)

  • MARTENSITIC TRANSFORMATION

A reaction that takes place in some metals on cooling, with the formation of an acicular structure called martensite.

  • MASH RESISTANCE SEAM WELD

A resistance seam weld made in a lap joint in which the thickness at the lap is reduced plastically to approximately the thickness of one of the lapped parts.

  • MASTER ALLOY

An alloy, rich in one or more desired addition elements, that can be added to a melt to raise the percentage of a desired constituent.

  • MATCH

A condition in which a point in one forging-die half is aligned properly with the corresponding point in the opposite die half within specified tolerance.

  • MATCH LINES

Same as matched edges.

  • MATCH PLATE

A plate of metal or other material on which patterns for metal casting are mounted (or formed as an integral part) so as to facilitate molding. The pattern is divided along its parting plane by the plate.

  • MATCHED EDGES

Two edges of a forging-die face that are machined exactly at 90� to each other, and from which all dimensions are taken in laying out the die impression and aligning the dies in the forging equipment

  • MATRIX

(1) The principal phase or aggregate in which another constituent is embedded. (2) In electroforming, a form used as a cathode.

  • MATTE

An intermediate product of smelting; an impure metallic sulfide mixture made by melting a roasted sulfide ore, such as an ore of copper, lead or nickel.

  • MATTE DIP

An etching solution used to produce a dull finish on metal.

  • MATTE FINISH

(1) A dull texture produced by rolling sheet or strip between rolls that have been roughened by blasting. (2) A dull finish characteristic of some electrodeposits, such as cadmium or tin. Also written mat finish.

  • MCQUAID-EHN TEST

A test to reveal grain size after heating into the austenitic temperature range. Eight standard McQuaid-Ehn grain sizes rate the structure, No. 8 being finest, No. 1 coarsest.

  • MEAN STRESS

(1) In fatigue loading, the algebraic mean of the maximum and minimum stress in one cycle. Also called the steady stress component. (2) In any multiaxial stress system, the algebraic mean of three principal stresses; more correctly called mean normal stress.

  • MECHANICAL EQUATION OF STATE

Any equation relating the stress, strain, strain rate and temperature that is based on the concept that the instantaneous value of any one of these quantities is a single-valued function of the others, regardless of the prior history of the deformation.

  • MECHANICAL HYSTERESIS

Energy absorbed in a complete cycle of loading and unloading within the elastic limit and represented by the closed loop of the stress-strain curves for loading and unloading. Sometimes referred to as elastic, but more properly, mechanical.

  • MECHANICAL PRESS

A press whose slide is operated by a crank, eccentric, cam toggle links or other mechanical device.

  • MECHANICAL PROPERTIES

The properties of a material that reveal its elastic and inelastic behavior when force is applied, thereby indicating its suitability for mechanical applications; for example, modulus of elasticity, tensile strength, elongation, hardness, and fatigue limit. Compare with physical properties.

  • MECHANICAL TESTING

Determination of mechanical properties.

  • MECHANICAL TWIN

A twin formed in a crystal by simple shear under external loading.

  • MECHANICAL WORKING

Subjecting metal to pressure, exerted by rolls, hammers or presses, in order to change the metal's shape or physical properties.

  • MELTING POINT

The temperature at which a pure metal, compound or eutectic changes from solid to liquid; the temperature at which the liquid and the solid are in equilibrium.

  • MELTING RANGE

The range of temperature over which an alloy other than a compound or eutectic changes from solid to liquid; the range of temperature from solidus to liquidus at any given composition on a constitution diagram.

  • MELTING RATE

In electric arc welding the weight or length of electrode melted in a unit of time. Sometimes called melt-off rate or burn-off rate.

  • MELT-OFF RATE

See melting rate.

  • MERCHANT BAR

A group of commodity steel shapes that consist of rounds, squares, flats, strip' angles, and channels, which fabricators, steel service centers and manufacturers bend and shape into products. Merchant products require more specialized processing than reinforcing bar

  • MERCHANT MILL

(obsolete) A mill, consisting of a group of stands of three rolls each arranged in a straight line and driven by one power unit, used to roll rounds, squares or flats of smaller dimensions than would be rolled on the bar mill.

  • MESH

The screen number of the finest screen of a specified standard screen scale through which almost all the particles of a powder sample will pass. Also called mesh size.

  • METAL

(1) An opaque lustrous elemental chemical substance that is a good conductor of heat and electricity and, when polished, a good reflector of light. Most elemental metals are malleable and ductile and are, in general, denser than the other elemental substances. (2) As to structure, metals may be distinguished from nonmetals by their atomic binding and electron availability. Metallic atoms tend to lose electrons from the outer shells, the positive ions thus formed being held together by the electron gas produced by the separation. The ability of these "free electrons" to carry an electric current, and the fact that this ability decreases as temperature increases, establish the prime distinctions of a metallic solid. (3) From the chemical viewpoint, an elemental substance whose hydroxide is alkaline. (4) An alloy.

  • METAL INERT-GAS WELDING

Gas metal arc welding using an inert gas such as argon as the shielding gas

  • METAL LEAF

Thin metal sheet, usually thinner than foil, and traditionally produced by beating rather than by rolling.

  • METAL PENETRATION

A surface condition in castings in which metal or metal oxides have filled voids between sand grains without displacing them.

  • METAL SPRAYING

Coating metal objects by spraying molten metal against the surface. See thermal spraying, flame spraying

  • METAL-ARC CUTTING

Any of a group of arc cutting processes that severs metals by melting them with the heat of an arc between a metal electrode and the work.

  • METAL-ARC WELDING

Any of a group of arc welding processes that fuses metals together using the heat of an arc between a metal electrode and the work. Use of the specific process name is preferred.

  • METALLIC GLASS

A noncrystalline metal or alloy, commonly produced by drastic supercooling of a molten alloy, by electrodeposition, or by vapor deposition. Also called amorphous alloy.

  • METALLIZING

(1) Forming a metallic coating by atomized spraying with molten metal or by vacuum deposition. Also called spray metallizing. (2) Applying an electrically conductive metallic layer to the surface of a nonconductor.

  • METALLOGRAPH

An optical instrument designed for both visual observation and photomicrography of prepared surfaces of opaque materials at magnifications ranging from about 25 to about 2000 diameters. The instrument consists of a high-intensity illuminating source, a microscope and a camera bellows. On some instruments, provisions are made for examination of specimen surfaces with polarized light, phase contrast, oblique illumination, darkfield illumination and customary brightfield illumination.

  • METALLOGRAPHY

The science dealing with the constitution and structure of metals and alloys as revealed by the unaided eye or by such tools as lowpowered magnification, optical microscope, electron microscope and diffraction or x-ray techniques.

  • METALLURGICAL COKE

A coke, usually low in sulfur, having a very high compressive strength at elevated temperatures; used in metallurgical furnaces not only as fuel, but also to support the weight of the charge.

  • METALLURGY

The science and technology of metals and alloys. Process metallurgy is concerned with the extraction of metals from their ores and with the refining of metals; physical metallurgy, with the physical and mechanical properties of metals as affected by composition, processing and environmental conditions; and mechanical metallurgy, with the response of metals to applied forces.

  • METASTABLE

Refers to a state of pseudoequilibrium that has a higher free energy than the true equilibrium state.

  • MF TEMPERATURE

For any alloy system the temperature at which martensite formation on cooling is essentially finished. See transformation temperature for the definition applicable to ferrous alloys.

  • MICROFISSURE

A crack of microscopic proportions.

  • MICROGRAPH

A graphic reproduction of the surface of a prepared specimen usually etched, at a magnification greater than ten diameters. If produced by photographic means it is called a photomicrograph (not a microphotograph).

  • MICROHARDNESS

The hardness of a material as determined by forcing an indenter such as a Vickers or Knoop indenter into the surface of a material under very light load; usually, the indentations are so small that they must be measured with a microscope. Capable of determining hardnesses of different microconstituents within a structure, or of measuring steep hardness gradients such as those encountered in case hardening.

  • MICROPROBE

See preferred term, electron beam microprobe analyzer.

  • MICRORADIOGRAPHY

The technique of passing x-rays through a thin section of an alloy in contact with a finegrained photographic film and then viewing the radiograph at 50 to 100X to observe the distribution of alloying constituents and voids.

  • MICROSCOPIC

Visible at magnifications greater than ten diameters.

  • MICROSCOPIC STRESSES

Residual stresses that vary from tension to compression in a distance (presumably approximating the grain size) that is small compared to the gage length in ordinary strain measurements. They are not detectable by dissection methods, but can sometimes be measured from line shift or line broadening in an x-ray diffraction pattern.

  • MICROSEGREGATION

Segregation within a grain, crystal or small particle.

  • MICROSHRINKAGE

A casting imperfection, not detectable microscopically, consisting of interdendritic voids. Microshrinkage results from contraction during solidification where there is not an adequate opportunity to supply filler material to compensate for shrinkage. Alloys with a wide range in solidification temperature are particularly susceptible.

  • MICROSTRESS

Same as microscopic stress.

  • MICROSTRUCTURE

The structure of metals as revealed by microscopic examination of the etched surface of a polished specimen.

  • MIDDLING

A product intermediate between concentrate and tailing and containing enough of a valuable mineral to make retreatment profitable.

  • MIG WELDING

See metal inert-gas welding.

  • MIGRATION

Movement of entities (such as electrons, ions, atoms, molecules, vacancies and grain boundaries) from one place to another under the influence of a driving force (such as an electrical potential or a concentration gradient).

  • MIL

One thousandth of an inch (0.001 in.).

  • MILD STEEL

Carbon steel with a maximum of about 0.25 percent C.

  • MILL

(1) A factory where metals are hot worked, cold worked, or melted and cast into standard shapes suitable for secondary fabrication into commercial products. (2) A production line, usually of four or more stands, for hot rolling metal into standard shapes such as bar, rod, plate, sheet or strip. (3) A single machine for hot rolling cold, rolling or extruding metal, examples include blooming mill, cluster mill, four-high mill, and Sendzimir mill. (4) A shop term for milling cutter. (5) A machine or group of machines for grinding or crushing ores and other minerals; see ball mill, milling (2).

  • MILL EDGE

The normal edge produced in hot rolling. This edge is customarily removed when hot rolled sheets are further processed into cold rolled sheets.

  • MILL FINISH

A nonstandard (and typically nonuniform) surface finish on mill products that are delivered without subjecting them to a special surface treatment (other than a corrosion preventive treatment) after the final working or heat treating step.

  • MILL PRODUCT

Any commercial product of a mill.

  • MILL SCALE

The heavy oxide layer formed during hot fabrication or heat treatment of metals.

  • MILLER INDICES

A system for identifying planes and directions in any crystal system by means of sets of integers. The indices of a plane are related to the intercepts of that plane with the axes of a unit cell; the indices of a direction, to the multiples of lattice parameter that represent the coordinates of a point on a line parallel to the direction and passing through the arbitrarily chosen origin of a unit cell.

  • MILLING

(1) Removing metal with a milling cutter. (2) The mechanical treatment of material, as in a ball mill, to produce particles or alter their size or shape, or to coat one component of a powder mixture with another.

  • MILLING CUTTER

A rotary cutting tool provided with one or more cutting elements, called teeth, which intermittently engage the workpiece and remove material by relative movement of the workpiece and cutter.

  • MINERAL DRESSING

Physical and chemical concentration of raw ore into a product from which a metal can be recovered at a profit.

  • MINI-MILLS

Normally defined as steel mills that melt scrap metal to produce commodity products. Although the mini-mills are subject to the same steel processing requirements after the caster as the integrated steel companies, they differ area regard to their minimum efficient size, labor relations, product markets, and management style

  • MINIMIZED SPANGLE

A hot dip galvanized coating of very small grain size which makes the spangle less visible when the part is subsequently painted.

  • MINIMUM BEND RADIUS

The minimum radius over which metal products can be bent to a given angle without fracture.

  • MINUS SIEVE

The portion of a sample of a granular substance (such as metal powder) that passes through a standard sieve of specified number. Contrast with plus sieve.

  • MISCHMETAL

A natural mixture of rare-earth elements (atomic numbers 57 through 71) in metallic form. It contains about 50 percent cerium, the remainder being principally lanthanum and neodymium.

  • MISMATCH

Error in register between forged surfaces formed by opposing dies.

  • MISRUN

A casting not fully formed, resulting from the metal solidifying before the mold is filled.

  • MIXING

In powder metallurgy, the thorough intermingling of powders of two or more different materials (not blending).

  • MIXING CHAMBER

The part of a torch or furnace burner in which gases are mixed.

  • MODIFICATION

Treatment of molten hypoeutectic (8 to 13 percent Si) or hypereutectic (13 to 19percent Si) aluminum-silicon alloys to improve mechanical properties of the solid alloy by refinement of the size and distribution of the silicon phase. Involves additions of small percentages of sodium or strontium (hypoeutectic alloys) or phosphorus (hypereutectic alloys).

  • MODULUS OF ELASTICITY

A measure of the rigidity of metal. Ratio of stress, below the proportional limit, to corresponding strain. Specifically, the modulus obtained in tension or compression is Young's modulus, stretch modulus or modulus of extensibility; the modulus obtained in torsion or shear is modulus of rigidity, shear modulus or modulus of torsion; the modulus covering the ratio of the mean normal stress to the change in volume per unit volume is the bulk modulus. The tangent modulus and secant modulus are not restricted within the proportional limit; the former is the slope of the stress-strain curve at a specified point; the latter is the slope of a line from the origin to a specified point on the stress-strain curve. Also called elastic modulus and coefficient of elasticity.

  • MODULUS OF RIGIDITY

See modulus of elasticity.

  • MODULUS OF RUPTURE

Nominal stress at fracture in a bend test or torsion test. In bending, modulus of rupture is the bending moment at fracture divided by the section modulus. In torsion, modulus of rupture is the torque at fracture divided by the polar section modulus.

  • MODULUS OF STRAIN HARDENING

See preferred term, rate of strain hardening.

  • MOH'S SCALE

A scratch hardness test for determining comparative hardness using ten standard minerals from talc (the softest) to diamond (the hardest).

  • MOLD

(1) A form made of sand, metal or other material that contains the cavity into which molten metal is poured to produce a casting of definite shape and outline. (2) Same as die.

  • MOLD JACKET

Wood or metal form that is slipped over a sand mold for support during pouring.

  • MOLD WASH

An aqueous or alcoholic emulsion or suspension of various materials used to coat the surface of a mold cavity.

  • MOLDING MACHINE

A machine for making sand molds by mechanically compacting sand around a pattern.

  • MOLDING PRESS

A press used to form powder metallurgy compacts.

  • MOLYBDENUM (MO)

An alloying element used as a raw material for some classes of stainless steel. Molybdenum in the presence of chromium enhances the corrosion resistance of stainless steel

  • MOND PROCESS

A process for extracting and purifying nickel. The main features consist of forming nickel carbonyl by reaction of finely divided reduced metal with carbon monoxide, then decomposing the nickel carbonyl, to deposit purified nickel on small nickel pellets.

  • MONOTECTIC

An isothermal reversible reaction in a binary system, in which a liquid on cooling decomposes into a second liquid of a different composition and a solid. It differs from a eutectic in that only one of the two products of the reaction is below its freezing range.

  • MONOTRON HARDNESS TEST

A method of determining the indentation hardness of metals by measuring the load required to force a spherical penetrator into the metal to a specified depth. Now obsolete.

  • MONOTROPISM

The ability of a solid to exist in two or more forms (crystal structures), but in which one form is the stable modification at all temperatures and pressures. Ferrite and martensite are a monotropic pair below Ac1 in steels, for example. May also be spelled monotrophism.

  • MONTHS OF INVENTORY

Ratio of the end-of-period inventory to average monthly level of sales for the period

  • MOSAIC STRUCTURE

In crystals, a substructure in which neighboring regions have only slightly differing orientations.

  • MS TEMPERATURE

For any alloy system, the temperature at which martensite starts to form on cooling. See transformation temperature for the definition applicable to ferrous alloys.

  • MULLING

Mixing sand and clay particles with water by kneading, rolling, rubbing or stirring.

  • MULTIAXIAL STRESSES

Any stress state in which two or three principal stresses are not zero.

  • MULTIPLE

A piece of stock cut from a longer mill product to provide the exact amount of material needed for a single workpiece.

  • MULTIPLE SPOT WELDING

Spot welding in which several spots are made during one complete cycle of the welding machine.

  • MULTIPLE-IMPULSE WELDING

Spot, projection or upset welding with more than one impulse of current during a single machine cycle. Sometimes called pulsation welding.

  • MULTIPLE-PASS WELD

A weld made by depositing filler metal with two or more successive passes.

  • NATIVE METAL

(1) Any deposit in the earth's crust consisting of uncombined metal. (2) The metal in such a deposit.

  • NATURAL AGING

Spontaneous aging of a supersaturated solid solution at room temperature. See aging, and compare with artificial aging.

  • NATURAL STRAIN

See strain.

  • NECKING

(1) Reducing the cross-sectional area of metal in a localized area by stretching. (2) Reducing the diameter of a portion of the length of a cylindrical shell or tube.

  • NECKING DOWN

Localized reduction in area of a specimen during tensile deformation.

  • NECKING STRAIN

Same as uniform strain.

  • NEGATIVE RAKE

Describes a tooth face in rotation whose cutting edge lags the surface of the tooth face. See sketch accompanying face mill.

  • NET OPERATING LOSS (NOLS)

An income-averaging provision that allows companies with losses to either carry forward the loss up to 15 years to offset otherwise taxable future income, or carry back the NOLs up to three years to receive a refund for taxes previously paid (see FAS 109)

  • NETWORK STRUCTURE

A structure in which one constituent occurs primarily at the grain boundaries, thus partially or completely enveloping the grains of the other constituents.

  • NEUMANN BAND

Mechanical twin in ferrite.

  • NEUTRAL FLAME

A gas flame in which there is no excess of either fuel or oxygen in the inner flame. Oxygen from ambient air is used to complete the combustion of CO2 and H2 produced in the inner flame.

  • NEUTRON

Elementary nuclear particle with a mass approximately the same as that of a hydrogen atom and electrically neutral; its mass is 1.008 986 mass units.

  • NEUTRON EMBRITTLEMENT

Embrittlement resulting from bombardment with neutrons, usually encountered in metals that have been exposed to a neutron flux in the core of a reactor. In steels, neutron embrittlement is evidenced by a rise in the ductile-to-brittle transition temperature.

  • NIBBLING

Contour cutting of sheet metal by a rapidly reciprocating punch making numerous small cuts.

  • NICKEL (NI)

An alloying element used as a raw material for certain classes of stainless steel. Nickel provides high degrees of ductility (ability to change shape without fracture) as well as resistance to corrosion. Approximately 65percent of all nickel is used in the making of stainless steel

  • NITRIDING

Introducing nitrogen into the surface layer of a solid ferrous alloy by holding at a suitable temperature (below Ac1 for ferritic steels) in contact with a nitrogenous material, usually ammonia or molten cyanide of appropriate composition. Quenching is not required to produce a hard case.

  • NITROCARBURIZING

Any of several processes in which both nitrogen and carbon are absorbed into the surface layers of a ferrous material at temperatures below the lower critical temperature and, by diffusion, create a concentration gradient. Nitrocarburizing is done mainly to provide an antiscuffing surface layer and to improve fatigue resistance. Compare with carbonitriding.

  • NO. 1 HEAVY MELT

Obsolete steel scrap grade, at least one-quarter inch in thickness and in sections no larger than five feet by two feet. Much of the metal comes from demolished buildings, truck frames and heavy duty springs. Mini-mills are primary consumers of No. 1 heavy scrap

  • NOBLE METAL

(1) A metal whose potential is highly positive relative to the hydrogen electrode. (2) A metal with marked resistance to chemical reaction, particularly to oxidation and to solution by inorganic acids. The term as often used is synonymous with precious metal. Contrast with base metal (4).

  • NOBLE POTENTIAL

The potential for the passive state, if the metal can exist in both the active and passive states in a given medium.

  • NODULAR POWDER

Irregular particles of a metal powder that have knotted, rounded or other similar shapes.

  • NOMINAL STRESS

See stress.

  • NONCONFORMING

A quality control term describing a unit of product or service that does not meet normal acceptance criteria for the specific product or service. A nonconforming unit is not necessarily defective.

  • NONDESTRUCTIVE INSPECTION

Inspection by methods that do not destroy the part nor impair its serviceability.

  • NONDESTRUCTIVE TESTING

Same as nondestructive inspection, but implying use of a method in which the part is stimulated and its response measured quantitatively or semiquantitatively.

  • NON-GRAIN-ORIENTED

Because there is no preferential direction for magnetization, non-grain-oriented steel is best used in rotating apparatus such as electric motors

  • NONMETALLIC INCLUSIONS

See inclusions.

  • NORMAL SEGREGATION

Concentration of alloying constituents that have low melting points in those portions of a casting that solidify last. Compare with inverse segregation.

  • NORMAL STRESS

See stress.

  • NORMALIZING

Heating a ferrous alloy to a suitable temperature above the transformation range and then cooling in air to a temperature substantially below the transformation range.

  • NOSE RADIUS

The radius of the rounded portion of the cutting edge of a tool. See sketch accompanying singlepoint tool.

  • NOSING

Closing in the end of a tubular shape to a desired curved contour.

  • NOTCH ACUITY

Relates to the severity of the stress concentration produced by a given notch in a particular structure. If the depth of the notch is very small compared with the width (or diameter) of the narrowest cross section, the acuity may be expressed as the ratio of the notch depth to the notch root radius. Otherwise, the acuity is defined as the ratio of one-half the width (or diameter) of the narrowest cross section to the notch root radius.

  • NOTCH BRITTLENESS

Susceptibility of a material to brittle fracture at points of stress concentration. For example, in a notch tensile test, the material is said to be notch brittle if the notch strength is less than the tensile strength of an unnotched specimen. Otherwise, it is said to be notch ductile.

  • NOTCH DEPTH

The distance from the surface of a test specimen to the bottom of the notch. In a cylindrical test specimen, the percentage of the original cross-sectional area removed by machining an annular groove.

  • NOTCH DUCTILE

See notch brittleness.

  • NOTCH DUCTILITY

The percentage reduction in area after complete separation of the metal in a tensile test of a notched specimen.

  • NOTCH RUPTURE STRENGTH

The ratio of applied load to original area of the minimum cross section in a stressrupture test of a notched specimen.

  • NOTCH SENSITIVITY

A measure of the reduction in strength of a metal caused by the presence of stress concentration. Values can be obtained from static, impact or fatigue tests.

  • NOTCH SHARPNESS

See notch acuity.

  • NOTCH STRENGTH

The maximum load on a notched tensile-test specimen divided by the minimum cross-sectional area (the area at the root of the notch). Also called notch tensile strength.

  • NOTCHING

Cutting out various shapes from the edge of a strip, blank or part.

  • NOTCHING PRESS

A mechanical press used for notching internal and external circumferences and also for notching along a straight line. These presses are equipped with automatic feeds, because only one notch is made per stroke.

  • NUCLEATION

The initiation of a phase transformation at discrete sites, the new phase growing on nuclei. See nucleus, (1).

  • NUCLEUS

(1) The first structurally stable particle capable of initiating recrystallization of a phase or the growth of a new phase, and possessing an interface with the parent matrix. The term is also applied to a foreign particle that initiates such action. (2) The heavy central core of an atom, in which most of the mass and the total positive electric charge are concentrated.

  • NUGGET

(1) A small mass of metal, such as gold or silver, found free in nature. (2) The weld metal in a spot, seam or projection weld.

  • OBSOLETE SCRAP

Iron-bearing items such as old automobiles; household appliances; farm, of fice and industrial equipment; ships and railroad cars; buildings and bridges that have completed their useful life which can be recovered from the junkyard and remelted. The residual impurity of such scrap normally relegates obsolete scrap to the mini-mills (see No. 1 Heavy Melt)

  • OCTAHEDRAL PLANE

In cubic crystals, a plane with equal intercepts on all three axes.

  • OFF TIME

In resistance welding, the time that the electrodes are off the work. This term is generally applied where the welding cycle is repetitive.

  • OFFAL

The material trimmed from blanks or formed panels.

  • OFFHAND GRINDING

Grinding where the operator manually forces the wheel against the work, or vice versa. It often implies casual manipulation of either grinder or work to achieve the desired result. Dimensions and tolerances frequently are not specified, or are only loosely specified; the operator relies mainly on visual inspection to determine how much grinding should be done. Contrast with precision grinding.

  • OFFSET

The distance along the strain coordinate between the initial portion of a stress-strain curve and a parallel line that intersects the stress-strain curve at a value of stress that is used as a measure of the yield strength. It is used for materials that have no obvious yield point. A value of 0.2percent is commonly used.

  • OIL CANNING

Same as canning

  • OIL COUNTRY TUBULAR GOODS (OCTG)

Label applied to the pipe products used by petroleum exploration customers. OCTG includes casing, drill pipe and oil well tubing, which, depending on their use, may be formed through welded or seamless processes

  • OILSTONE

A natural or manufactured abrasive stone, generally impregnated with oil, used for sharpening keen-edged tools.

  • OLSEN DUCTILITY TEST

A cupping test in which a piece of sheet metal, restrained except at the center, is deformed by a standard steel ball until fracture occurs. The height of the cup (in thousandths of an inch) at time of fracture is a measure of the ductility.

  • OPEB EXPENSE

Other Postretirement Employment Benefits. Usually refers to health care obligations to a mill's retired workers, although its meaning also can include layoff benefits (see FAS 106)

  • OPEN DIE FORGING

Same as flat die forging.

  • OPEN DIES

See closed dies.

  • OPEN HEARTH FURNACE

A broad, shallow hearth to refine pig iron and scrap into steel. Heat is supplied from a large, luminous flame over the surface, and the refining takes seven to nine hours. Open Hearths, at one time the most abundant steelmaking furnaces among integrated companies, have been replaced by the basic oxygen furnace

  • OPEN-BACK INCLINABLE PRESS

A vertical crank press that can be inclined so that the bed will have an inclination generally varying from 0� to 30�. The formed parts slide off through an opening in the back. It is often called an OBI press.

  • OPEN-GAP UPSET WELDING

A form of forge welding in which the weld interfaces are heated with a fuel gas flame, then forced into intimate contact by the application of force. Not to be confused with upset welding, which is a resistance welding process.

  • OPEN-HEARTH FURNACE

A reverberatory melting furnace with a shallow hearth and a low roof. The flame passes over the charge on the hearth causing the charge to be heated both by direct flame and by radiation from the roof and sidewalls of the furnace. In ferrous industry, the furnace is regenerative.

  • OPERATING RATES

The ratio of raw steel production to the mill's stated capacity. Each December, steel companies report to the AISI their estimated capacity (if they could sell all steel they produced) for the following year, adjusted for any facility downtime

  • OPERATING STRESS

The stress to which a structural unit is subjected in service.

  • OPTICAL PYROMETER

An instrument for measuring the temperature of heated material by comparing the intensity of light emitted with a known intensity of an incandescent lamp filament.

  • ORANGE PEEL

A surface roughening in the form of a pebble-grained pattern where a metal of unusually coarse grain is stressed beyond its elastic limit. Also called pebbles and alligator skin.

  • ORDER RATE

The ratio of new orders recorded to the mill's capacity to produce the steel to fill the orders. Many analysts view trends in the order rate as harbingers of future production levels

  • ORDERING

Forming a superlattice.

  • ORE

A natural mineral that may be mined and treated for the extraction of any of its components, metallic or otherwise, at a profit.

  • ORE DRESSING

Same as mineral dressing.

  • ORIENTATION

Arrangement in space of the axes of a crystal with respect to a chosen reference or coordinate system. See also preferred orientation.

  • OSCILLATING

A method of winding narrow strip steel over a much wider roll. Customers wan have as much steel on a coil as will fit in their machines, so they can spend less moving the material and more time using it. By coiling the strip like fishing fin' thread) over a spool, a much longer strip can fit onto a coil of proper diameter. Oscillate-wound coils allow the customer to enjoy longer processing runs

  • OSCILLATING DIE PRESS

A small highspeed press in which the die and punch move horizontally with the strip during the working stroke. Through a reciprocating motion, the die and punch return to their original positions to begin the next stroke.

  • OVERAGING

Aging under conditions of time and temperature greater than those required to obtain maximum change in a certain property, so that the property is altered in the direction of the initial value. See aging.

  • OVERBENDING

Bending metal through a greater arc than that required in the finished part, to compensate for springback.

  • OVERDRAFT

A condition where a metal curves upward on leaving the rolls because of the higher speed of the lower roll.

  • OVERHAULING

Cutting surface layers from castings or slabs to remove scale and surface imperfections. Sometimes called scalping or slab milling.

  • OVERHEAD-DRIVE PRESS

A mechanical press with the driving mechanism mounted in or on the crown or upper parts of the uprights.

  • OVERHEAD-POSITION WELDING

Welding that is performed from the underside.

  • OVERHEATING

Heating a metal or alloy to such a high temperature that its properties are impaired. When the original properties cannot be restored by further heat treating, by mechanical working or by a combination of working and heat treating, the overheating is known as burning.

  • OVERLAP

(1) Protrusion of weld metal beyond the toe, face or root of a weld. (2) In resistance seam welding, the area in a given weld remelted by the succeeding weld.

  • OVERSIZE POWDER

Particles of a powdered metal coarser than the maximum permitted by a given specification for particle size.

  • OVERSTRESSING

(1) In fatigue testing, cycling at a stress level higher than that used at the end of the test.

  • OVERVOLTAGE

The difference between the actual electrode potential when appreciable electrolysis begins and the reversible electrode potential.

  • OXIDATION

(1) A reaction in which there is an increase in valence resulting from a loss of electrons. Contrast with reduction. (2) A corrosion reaction in which the corroded metal forms an oxide; usually applied to reaction with a gas containing elemental oxygen, such as air.

  • OXIDIZED SURFACE (ON STEEL)

Surface having a thin, tightly adhering, oxidized skin (from straw to blue in color), extending in from the edge of a coil or sheet. Sometimes called annealing border.

  • OXIDIZING AGENT

A compound that causes oxidation, thereby itself becoming reduced.

  • OXIDIZING FLAME

A gas flame produced with excess oxygen in the inner flame.

  • OXYACETYLENE CUTTING

An oxyfuel gas cutting process in which the fuel gas is acetylene.

  • OXYACETYLENE WELDING

An oxyfuel gas welding process in which the fuel gas is acetylene.

  • OXYFUEL GAS CUTTING

Any of a group of processes used to sever metals by means of chemical reaction between hot base metal and a fine stream of oxygen. The necessary metal temperature is maintained by gas flames resulting from combustion of a specific fuel gas such as acetylene, hydrogen, natural gas or propane. See also oxygen cutting.

  • OXYFUEL GAS WELDING

Any of a group of processes used to fuse metals together by heating them with gas flames resulting from combustion of a specific fuel gas such as acetylene, hydrogen, natural gas or propane. The process may be used with or without the application of pressure to the joint, and with or without adding any filler metal.

  • OXYGEN CUTTING

Metal cutting by directing a fine stream of oxygen upon a hot metal. The chemical reaction between oxygen and the base metal furnishes heat for localized melting, hence, cutting.

  • OXYGEN DEFICIENCY

A form of crevice corrosion in which galvanic corrosion proceeds because oxygen is prevented from diffusing into the crevice.

  • OXYGEN GOUGING

Oxygen cutting in which a chamfer or groove is formed.

  • OXYGEN LANCE

A length of pipe used to convey oxygen, either to the point of cutting in oxygen-lance cutting, or beneath the surface of the melt in a steelmaking furnace.

  • OXYGEN-FREE COPPER

Electrolytic copper free from cuprous oxide, produced without the use of residual metallic or metalloidal deoxidizers.

  • OXYHYDROGEN CUTTING

An oxyfuel gas cutting process in which the fuel gas is hydrogen.

  • OXYHYDROGEN WELDING

An oxyfuel gas welding process in which the fuel gas is hydrogen.

  • OXYNATURAL GAS CUTTING

An oxyfuel gas cutting process in which the fuel gas is natural gas.

  • OXYNATURAL GAS WELDING

An oxyfuel gas welding process in which the fuel gas is natural gas.

  • OXYPROPANE CUTTING

An oxyfuel gas cutting process in which the fuel gas is propane.

  • OXYPROPANE WELDING

An oxyfuel gas welding process in which the fuel gas is propane.

  • PACK ROLLING

Hot rolling a pack of two or more sheets of metal; scale prevents their being welded together.

  • PACKING MATERIAL

Any material in which powder metallurgy compacts are embedded during the presintering or sintering operations.

  • PANCAKE FORGING

A rough forged shape, usually flat, that may be obtained quickly with a minimum of tooling. It usually requires considerable machining to attain finish size.

  • PARAMAGNETIC MATERIAL

A material whose specific permeability is greater than unity and is practically independent of the magnetizing force. Compare with diamagnetic material, ferromagnetic material.

  • PARKES PROCESS

A process used to recover precious metals from lead and based on the principle that if 1 to 2percent Zn is stirred into the molten lead, a compound of zinc with gold and silver separates out and can be skimmed off.

  • PARTIAL ANNEALING

An imprecise term used to denote a treatment given cold worked material to reduce the strength to a controlled level or to effect stress relief. To be meaningful, the type of material, the degree of cold work, and the time-temperature schedule must be stated.

  • PARTICLE SIZE

The controlling lineal dimension of an individual particle, such as of a powdered metal, as determined by analysis with screens or other suitable instruments.

  • PARTICLE SIZE DISTRIBUTION

The percentage, by weight or by number, of each fraction into which a powder sample has been classified with respect to sieve number or particle size. Preferred usage: "particle size distribution by weight", or "particle size distribution by frequency".

  • PARTING

(1) In the recovery of precious metals, the separation of silver from gold. (2) The zone of separation between cope and drag portions of mold or flask in sand casting. (3) A composition sometimes used in sand molding to facilitate the removal of the pattern. (4) Cutting simultaneously along two parallel lines or along two lines that balance each other in side thrust. (5) A shearing operation used to produce two or more parts from a stamping.

  • PARTING LINE

(1) The intersection of the parting plane of a casting mold or the parting plane between forging dies with the mold or die cavity. (2) A raised line or projection on the surface of a casting or forging that corresponds to said intersection.

  • PARTING PLANE

(1) In forging, the dividing plane between dies. Contrast with forging plane. (2) In casting, the dividing plane between mold halves.

  • PARTING SAND

Fine sand for dusting on sand mold surfaces that are to be separated.

  • PARTS FORMER

A type of upsetter designed to work on short billets instead of bars and tubes, usually for cold forging.

  • PASS

(1) A single transfer of metal through a stand of rolls. (2) The open space between two grooved rolls through which metal is processed. (3) The weld metal deposited in one trip along the axis of a weld.

  • PASSIVATION

The changing of a chemically active surface of a metal to a much less reactive state. Contrast with activation.

  • PASSIVITY

A condition in which a piece of metal, because of an impervious covering of oxide or other compound, has a potential much more positive than when the metal is in the active state.

  • PATENT LEVELING

Same as stretcher leveling.

  • PATENTING

In wiremaking, a heat treatment applied to medium-carbon or high-carbon steel before the drawing of wire or between drafts. This process consists of heating to a temperature above the transformation range and then cooling to a temperature below Ae1 in air or in a bath of molten lead or salt.

  • PATTERN

(1) A form of wood, metal or other material, around which molding material is placed to make a mold for casting metals. (2) A full-scale reproduction of a part used as a guide in cutting.

  • PATTINSON PROCESS

A process for separating silver from lead, in which the molten lead is slowly cooled so that crystals poorer in silver solidify out and are removed, leaving the melt richer in silver.

  • PEAK EARNINGS

The ultimate earnings level of a company at the top of the business cycle. This is the expected profit during the time of the highest commodity demand and the strongest product pricing

  • PEARLITE

A metastable lamellar aggregate of ferrite and cementite resulting from the transformation of austenite at temperatures above the bainite range.

  • PEARLITIC MALLEABLE

See malleable cast iron.

  • PEBBLES

Same as orange peel.

  • PEELING

The detaching of one layer of a coating from another or from the basis metal, because of poor adherence.

  • PEENING

Mechanical working of metal by hammer blows or shot impingement.

  • PELLETS

Iron ore or limestone particles are rolled into little balls in a balling drum and hardened by heat

  • PELLETS

(See Agglomerating Processes)

  • PENETRANT

A liquid with low surface tension used in liquid penetrant inspection to flow into surface openings of parts being inspected.

  • PENETRANT INSPECTION

See preferred term, liquid penetrant inspection.

  • PENETRATION

(1) In founding, an imperfection on a casting surface caused by metal running into voids between sand grains; usually referred to as metal penetration. (2) In welding, the distance from the original surface of the base metal to that point at which fusion ceased. See joint penetration.

  • PENETRATION HARDNESS

Same as indentation hardness.

  • PERCUSSION WELDING

Resistance welding in which abutting surfaces are heated by an intense spark between them, welding being consummated by applying a hammerlike blow during or immediately after the electrical discharge.

  • PERFORATING

Piercing holes of desired shapes arranged in a definite pattern in sheets, blanks or formed parts.

  • PERIODIC REVERSE

Pertains to periodic changes in direction of flow of the current in electrolysis. It applies to the process and also the machine that controls the time for both directions.

  • PERIPHERAL CLEARANCE ANGLE

See clearance angle, and also sketch accompanying face mill.

  • PERIPHERAL MILLING

Milling a surface parallel to the axis of the cutter.

  • PERIPHERAL SPEED

See preferred term, cutting speed.

  • PERITECTOID

An isothermal reversible reaction in which a solid phase reacts with a second solid phase to produce a single (and different) solid phase on cooling.

  • PERMANENT MOLD

A metal, graphite or ceramic mold (other than an ingot mold) of two or more parts that is used repeatedly for the production of many castings of the same form. Liquid metal is poured in by gravity.

  • PERMANENT SET

Plastic deformation that remains upon releasing the stress that produces the deformation.

  • PERMEABILITY

(1) In founding, the characteristics of molding materials that permit gases to pass through them. "Permeability number" is determined by a standard test. (2) In powder metallurgy, a property measured as the rate of passage under specified conditions of a liquid or gas through a compact. (3) A general term used to express various relationships between magnetic induction and magnetizing force. These relationships are either "absolute permeability", which is a change in magnetic induction divided by the corresponding change in magnetizing force, or "specific (relative) permeability", the ratio of the absolute permeability to the permeability of free space.

  • PEWTER

Any of various alloys in which tin is the chief constituent; especially an alloy of tin and lead formerly used for domestic utensils.

  • PH

The negative logarithm of the hydrogen ion activity; it denotes the degree of acidity or basicity of a solution. At 25 �C (76 �F), 7.0 is the neutral value. Decreasing values below 7.0 indicate increasing acidity; in- creasing values above 7.0, increasing basicity.

  • PHASE DIAGRAM

Same as constitution diagram.

  • PHOSPHATING

Forming an adherent phosphate coating on a metal by immersion in a suitable aqueous phosphate solution. Also called phosphatizing.

  • PHOSPHORIZED COPPER

General term applied to copper deoxidized with phosphorus. The most commonly used deoxidized copper.

  • PHOTOELASTICITY

An optical method for evaluating the magnitude and distribution of stresses, using a transparent model of a part, or a thick film of photoelastic material bonded to a real part.

  • PHOTOMACROGRAPH

See macrograph.

  • PHOTOMICROGRAPH

See micrograph.

  • PHOTON

The smallest possible quantity of an electromagnetic radiation that can be characterized by a definite frequency.

  • PHYSICAL METALLURGY

The science and technology dealing with the properties of metals and alloys, and of the effects of composition, processing and environment on those properties.

  • PHYSICAL PROPERTIES

Properties of a metal or alloy that are relatively insensitive to structure and can be measured without the application of force; for example, density, electrical conductivity, coefficient of thermal expansion, magnetic permeability and lattice parameter. Does not include chemical reactivity. Compare with mechanical properties.

  • PHYSICAL TESTING

Determination of physical properties.

  • PICKLE LIQUOR

A spent acid-pickling bath.

  • PICKLE PATCH

A tightly adhering oxide or scale coating not properly removed during pickling.

  • PICKLE STAIN

Discoloration of metal due to chemical cleaning without adequate washing and drying.

  • PICKLING

Removing surface oxides from metals by chemical or electrochemical reaction.

  • PICKLING

WHAT. Process that cleans a steel coil of its rust, dirt and oil so that further work can be done to the metal. WHY. When hot-rolled coils cool, rust forms on the unprotected metal; often coils are stored or transported while exposed to outside air and water. HOW. Through a continuous process, the steel is uncoiled and sent through a serf of hydrochloric acid baths that remove the oxides (rust). The steel sheet is then rinsed and dried

  • PICKOFF

An automatic device for removing a finished part from the press die after it has been stripped.

  • PICKUP

Transfer of metal from tools to part or from part to tools during a forming operation. See galling.

  • PIDGEON PROCESS

A process for the production of magnesium by the reduction of magnesium oxide with ferrosilicon.

  • PIEZOELECTRIC EFFECT

The reversible interaction, exhibited by some crystalline materials, between an elastic strain and an electric field. The direction of the strain depends on the polarity of the field or vice versa. Compare with electrostrictive effect.

  • PIG

A metal casting used in remelting.

  • PIG IRON

(1) High-carbon iron made by reduction of iron ore in the blast furnace. (2) Cast iron in the form of pigs.

  • PIG IRON

The name for the melted iron produced in a blast furnace, containing a large quantity of carbon (above 1.5percent). Named long ago when molten iron was poured through a trench in the ground to flow into shallow earthen holes, the arrangement looked lid newborn pigs suckling. The central channel became known as the "sow," and the molds were "pigs"

  • PILGER TUBE-REDUCING PROCESS

See tube reducing.

  • PILING (SHEET PILING)

A structural steel product with edges designed to interlock; used in the construction of cofferdams or riverbank reinforcement

  • PIN EXPANSION TEST

A test for determining the ability of tubes to be expanded or for revealing the presence of cracks or other longitudinal weaknesses, made by forcing a tapered pin into the open end of a tube.

  • PINCH PASS

A pass of sheet material through rolls to effect a very small reduction in thickness.

  • PINCHERS

Surface disturbances that result from rolling processes and that ordinarily appear as fernlike ripples running diagonally to the direction of rolling.

  • PINE-TREE CRYSTAL

A type of dendrite.

  • PINHEAD BLISTER

See blister.

  • PINHOLE POROSITY

Porosity consisting of numerous small gas holes distributed throughout the metal; found in weld metal, castings or eleckodeposited metal.

  • PINION

The smaller of two mating gears.

  • PIOBERT LINES

Same as L�ders lines.

  • PIPE

(1) The central cavity formed by contraction in metal, especially ingots, during solidification. See accompanying sketch. (2) An imperfection in wrought or cast products resulting from such a cavity. (3) See extrusion pipe. (4) A tubular metal product, cast or wrought.

  • PIPE

Technically a tube is used to transport fluids or gases. However, pipe and tube are often used interchangeably in steel lexicon, with a given label applied primarily as matter of historical use

  • PIPE TAP

A tap for making internal pipe threads within pipe fittings or holes.

  • PIPE THREADS

Internal or external machine threads, usually tapered, of a design intended for making pressuretight mechanical joints in piping systems.

  • PITCH

See set.

  • PITTING

Forming small sharp cavities in a metal surface by nonuniform electrodeposition or by corrosion.

  • PLANCHET

A metal disk with milled edges, ready for coining.

  • PLANE STRAIN

The stress condition in linear elastic fracture mechanics in which there is zero strain in a direction normal to both the axis of applied tensile stress and the direction of crack growth (i.e., parallel to the crack front); most nearly achieved in loading thick plates along a direction parallel to the plate surface. Under plane-strain conditions, the plane of fracture instability is normal to the axis of the principal tensile stress.

  • PLANE STRESS

The stress condition in linear elastic fracture mechanics in which the stress in the thickness direction is zero; most nearly achieved in loading very thin sheet along a direction parallel to the surface of the sheet. Under plane-stress conditions, the plane of fracture instability is inclined 45� to the axis of the principal tensile stress.

  • PLANIMETRIC METHOD

A method of measuring grain size in which the grains within a definite area are counted.

  • PLANING

Producing flat surfaces by linear reciprocal motion of work and the table to which it is attached, relative to a stationary single-point cutting tool.

  • PLANISHING

Producing a smooth surface finish on metal by a rapid succession of blows delivered by highly polished dies or by a hammer designed for the purpose, or by rolling in a planishing mill.

  • PLASMA SPRAYING

A thermal spraying process in which the coating material is melted with heat from a plasma torch that generates a nontransferred arc (defined in plasma-arc welding); molten coating material is propelled against the basis metal by the hot, ionized gas issuing from the torch.

  • PLASMA-ARC CUTTING

An arc cutting process that severs metals by melting a localized area with heat from a constricted arc and removing the molten metal with a high-velocity jet of hot, ionized gas issuing from the plasma torch.

  • PLASMA-ARC WELDING

An arc-welding process that produces coalescence of metals by heating them with a constricted arc between an electrode and the workpiece (transferred arc) or the electrode and the constricting nozzle (nontransferred arc). Shielding is obtained from hot, ionized gas issuing from an orifice surrounding the electrode and may be supplemented by an auxiliary source of shielding gas, which may be an inert gas or a mixture of gases. Pressure may or may not be used, and filler metal may or may not be supplied.

  • PLASTER MOLDING

Molding wherein a gypsum-bonded aggregate flour in the form of a water slurry is poured over a pattern, permitted to harden, and, after removal of the pattern, thoroughly dried. The technique is used to make smooth nonferrous castings of accurate size.

  • PLASTIC DEFORMATION

Deformation that does or will remain permanent after removal of the load that caused it.

  • PLASTIC FLOW

Same as plastic deformation.

  • PLASTICITY

The ability of a metal to deform nonelastically without rupture.

  • PLATE

A flat-rolled metal product of some minimum thickness and width arbitrarily dependent on the type of metal.

  • PLATE

Sheet steel with a width of more than eight inches, with a thickness ranging from one quarter of an inch to more than one foot (see Sheet Steel)

  • PLATEN

(1) Face of a bolster, slide or ram to which a tool assembly is attached. (2) A part of a resistance welding, mechanical testing or other machine with a flat surface to which dies, fixtures, backups or electrode holders are attached and that transmits pressure or force.

  • PLATING

Forming an adherent layer of metal upon an object; often used as a shop term for electroplating.

  • PLATING RACK

A fixture used to hold work and conduct current to it during electroplating.

  • PLATING RANGE

The current density range over which a satisfactory electroplate can be deposited.

  • PLATINUM BLACK

A finely divided form of platinum of a dull black color, usually but not necessarily produced by the reduction of salts in aqueous solution.

  • PLUG

(1) A rod or mandrel over which a pierced tube is forced. (2) A rod or mandrel that fills a tube as it is drawn through a die. (3) A punch or mandrel over which a cup is drawn. (4) A protruding portion of a die impression for forming a corresponding recess in the forging. (5) A false bottom in a die. Also called a "peg".

  • PLUG TAP

A tap with chamfer extending from three to five threads.

  • PLUG WELD

A circular weld made by either arc or gas welding through one member of a lap or tee joint. If a hole is used, it may be only partly filled. Neither a fillet-welded hole nor a spot weld is to be construed as a plug weld.

  • PLUMBAGO

A special quality of powdered graphite used to coat molds and in a mixture with clay, to make crucibles.

  • PLUNGE GRINDING

Grinding where the only relative motion of the wheel is radially toward the work.

  • PLUS SIEVE

The portion of a sample of a granular substance (such as metal powder) retained on a standard sieve of specified number. Contrast with minus sieve.

  • PLYMETAL

Sheet consisting of bonded layers of dissimilar metals.

  • PM 2.5

The moniker for the Environmental Protection Agency's new Particulate Matter standards. The EPA is revising current PM standards and establishing a new PM 2.5 standard regarding the release of particulate matter down to 2.5 micrometers in diameter (less than one-third the width of a human hair)

  • POINT ANGLE

In general, the angle at the point of a cutting tool. Most commonly, the included angle at the point of a twist drill, the general-purpose angle being 118�.

  • POINTING

(1) Reducing the diameter of wire, rod or tubing over a short length at the end by swaying or hammer forging, turning or squeezing to facilitate entry into a drawing die and gripping in the drawhead. (2) The operation in automatic machines of chamfering or rounding the threaded end or the head of a bolt.

  • POISSON'S RATIO

The absolute value of the ratio of the transverse strain to the corresponding axial strain, in a body subjected to uniaxial stress; usually applied to elastic conditions.

  • POKE WELDING

Same as push welding.

  • POLAR BOND

See ionic bond.

  • POLARIZATION

A change in the potential of an electrode during electrolysis, such that the potential of an anode becomes more noble and that of a cathode more active than their respective reversible potentials. Often accomplished by the formation of a film on the electrode surface.

  • POLE

(i) A means of designating the orientation of a crystal plane by stereographically plotting its normal. For example, the north pole defines the equatorial plane. (2) Either of the two regions of a permanent magnet or electromagnet where most of the lines of induction enter or leave.

  • POLE FIGURE

A stereographic projection representing the statistical average distribution of poles of a specific crystalline plane in a polycrystalline metal, with reference to an external system of axes. In an isotropic metal, that is, in one having a completely random distribution of orientations, the pole density is stereographically uniform, preferred orientation is shown by an increased density of poles in certain areas.

  • POLING

A step in the fire refining of copper to reduce the oxygen content to tolerable limits by covering the bath with coal or coke and thrusting green wood poles below the surface. There is a vigorous evolution of reducing gases that combine with the oxygen contained in the metal.

  • POLISHING

Smoothing metal surfaces, often to a high luster, by rubbing the surface with a fine abrasive, usually contained in a cloth or other soft lap. Results in microscopic flow of some surface metal together with actual removal of a small amount of surface metal. May be extended to include electropolishing. Contrast with buffing, burnishing.

  • POLYCRYSTALLINE

Pertaining to a solid composed of many crystals.

  • POLYMORPHISM

A general term for the ability of a solid to exist in more than one form. In metals, alloys and similar substances, this usually means the ability to exist in two or more crystal structures, or an amorphous state and at least one crystal structure. See also allotropy, enantiotropy, monotropism.

  • POP-OFF

Loss of small portions of a porcelain enamel coating. The usual cause is outgassing of hydrogen or other gases from the basis metal during firing, but pop-off also may occur because of oxide particles or other debris on the surface of the basis metal. Usually, the pits are minute and cone shaped, but when pop-off is the result of severe fishscale the pits may be much larger and irregular.

  • PORES

(1) Small voids in the body of a metal. (2) Minute cavities in a powder metallurgy compact, sometimes intentional. (3) Minute perforations in an electroplated coating.

  • POROSITY

Fine holes or pores within a metal.

  • PORTHOLE DIE

A multiple-section extrusion die capable of producing tubing or intricate hollow shapes without the use of a separate mandrel. Metal is extruded in separate streams through holes in each section and is rewelded by extrusion pressure before it leaves the die. Compare with bridge die.

  • POSITIONED WELD

A weld made in a joint that has been oriented to facilitate making the weld.

  • POSITIVE RAKE

Describes a tooth face in rotation whose cutting edge leads the surface of the tooth face. See sketch accompanying face mill.

  • POSTHEATING

Heating weldments immediately after welding, for tempering, for stress relieving, or for providing a controlled rate of cooling to prevent formation of a hard or brittle structure.

  • POT

(1) A vessel for holding molten metal. (2) The electrolytic reduction cell used to make such metals as aluminum from a fused electrolyte.

  • POT ANNEALING

Same as box annealing.

  • POT DIE FORMING

Forming products from sheet or plate through the use of a hollow die and internal pressure which causes the preformed workpiece to assume the contour of the die.

  • POULTICE CORROSION

A term used in the automotive industry to describe the corrosion of vehicle body parts due to the collection of road salts and debris on ledges and in pockets that are kept moist by weather and washing.

  • POURING

Transferring molten metal from a furnace or a ladle to a mold.

  • POURING BASIN

A basin on top of a mold to receive the molten metal before it enters the sprue or downgate.

  • POWDER

Particles of a solid characterized by small size, nominally within the range of 0.1 to 1000 �m.

  • POWDER LUBRICANT

An agent mixed with or incorporated in a powder to facilitate the pressing and ejecting of a powder metallurgy compact.

  • POWDER METALLURGY

The art of producing metal powders and of utilizing metal powders for the production of massive materials and shaped objects.

  • POWDER METALLURGY FORGING

Plastically deforming a powder metallurgy compact or preform into a fully dense finished shape using compressive force; usually done hot, and usually within closed dies.

  • POWDER METALS

Fabrication technology in which fine metallic powder is compacted under high pressure and then heated at a temperature slightly below the melting point to solidify the material. Primary users of powder metal parts are auto, electronics and aerospace industries

  • POWER REEL

A reel that is driven by an electric motor or some other source of power, used to wind or coil strip or wire as it is drawn through a continuous normalizing furnace, through a die, or through rolls as in certain types of cold mills in which the work rolls are not driven.

  • PRECHARGE

In forming, the pressure introduced into the cavity prior to forming the part.

  • PRECIOUS METAL

One of the relatively scarce and valuable metals: gold, silver and the platinum-group metals.

  • PRECIPITATION HARDENING

Hardening caused by the precipitation of a constituent from a supersaturated solid solution. See also age hardening and aging.

  • PRECIPITATION HARDENING (PH)

A small group of stainless steels with high chromium and nickel content, with the most common types having characteristics close to those of martensitic (plain chromium stainless class with exceptional strength) steels. Heat treatment provides this class with its very high strength and hardness. Applications for PH stainless steels include shafts for pumps and valves as well as aircraft parts

  • PRECIPITATION HEAT TREATMENT

Artificial aging in which a constituent precipitates from a supersaturated solid solution.

  • PRECISION

The closeness of approach of each of a number of similar measurements to the arithmetic mean, the sources of error not necessarily being considered critically. Accuracy demands precision, but precision does not ensure accuracy.

  • PRECISION CASTING

A metal casting of reproducible accurate dimensions regardless of how it is made.

  • PRECISION GRINDING

Machine grinding to specified dimensions and low tolerances. Contrast with offhand grinding.

  • PRECOAT

(1) In investment casting, a special refractory slurry applied to a wax or plastic expendable pattern to form a thin coating that serves as a desirable base for application of the main slurry. (2) Making the thin coating. (3) The thin coating itself.

  • PRECOATED METAL PRODUCTS

Mill products that have a metallic, organic or conversion coating applied to their surfaces before they are fabricated into parts.

  • PREFERRED ORIENTATION

A condition of a polycrystalline aggregate in which the crystal orientations are not random, but rather exhibit a tendency for alignment with a specific direction in the bulk material, commonly related to the direction of working; also called texture.

  • PREFORMING

(1) The initial pressing of a metal powder to form a compact that is to be subjected to a subsequent pressing operation other than coining or sizing. Also, the preliminary shaping of a refractory metal compact after presintering and before the final sintering. (2) Preliminary forming operations, especially for impression die forging.

  • PREHEATING

Heating before some further thermal or mechanical treatment. For tool steel, heating to an intermediate temperature immediately before final austenitizing. For some nonferrous alloys, heating to a high temperature for a long time, in order to homogenize the structure before working. In welding and related processes, heating to an intermediate temperature for a short time immediately before welding, brazing, soldering, cutting or thermal spraying.

  • PRESINTERING

The heating of a powder metallurgy compact to a temperature lower than the normal temperature for final sintering, usually to increase the ease of handling or forming the compact or to remove a lubricant or binder before sintering.

  • PRESS

A machine tool having a stationary bed and a slide or ram that has reciprocating motion at right angles to the bed surface, the slide being guided in the frame of the machine.

  • PRESS BRAKE

An open-frame single-action press used to bend, blank, corrugate, curl, notch, perforate, pierce or punch sheet metal or plate.

  • PRESS FIT

An interference or force fit made through the use of a press.

  • PRESS FORGING

Forging metal, usually hot, between dies in a press.

  • PRESSED DENSITY

The density of an unsintered powder metallurgy compact. Sometimes called green density.

  • PRESSING

(1) In metalworking, the product or process of shallow drawing sheet or plate. (2) Forming a powdermetal part with compressive force.

  • PRESSING AREA

The clear distance (left to right) between housings, stops gibs, gibways or shoulders of strain rods, multiplied by the total distance from front to back on the bed of a press. Sometimes called working area.

  • PRESSING CRACK

A rupture in a green powder metallurgy compact that develops during the ejection of the compact from the die; see also capping and lamination. Sometimes referred to as a slip crack.

  • PRESSURE CASTING

(1) Making castings with pressure on the molten or plastic metal, as in injection molding, die casting, centrifugal casting, and cold chamber pressure casting. (2) A casting made with pressure applied to the molten or plastic metal.

  • PRESSURE GAS WELDING

An oxyfuel gas welding process that produces coalescense simultaneously over the entire area of abutting surfaces by heating them with gas flames obtained from the combustion of a fuel gas with oxygen and by the application of pressure, without the use of filler metal.

  • PRIMARY CREEP

See creep.

  • PRIMARY CRYSTAL

The first type of crystal that separates from a melt on cooling.

  • PRIMARY CURRENT DISTRIBUTION

The current distribution in an electrolytic cell that is free of polarization.

  • PRIMARY METAL

Metal extracted from minerals and free of reclaimed metal scrap. C

  • PRIMARY MILL

A mill for rolling ingots or the rolled products of ingots to blooms, billets or slabs. This type of mill is often called a blooming mill and sometimes a cogging mill.

  • PRIMES

Metal products, principally sheet and plate, of the highest quality and free from blemishes or other visible imperfections.

  • PRINCIPAL STRESSES

The normal stresses on three mutually perpendicular planes on which there are no shear stresses.

  • PRISMATIC PLANE

In noncubic crystals, any plane that is parallel to the principal axis (c axis).

  • PROCESS ANNEALING

An imprecise term denoting various treatments used to improve workability. For the term to be meaningful, the condition of the material and the time temperature cycle used must be stated.

  • PROCESS METALLURGY

The science and technology of winning metals from their ores and purifying metals; sometimes referred to as chemical metallurgy. Its two chief branches are extractive metallurgy and refining.

  • PROCESS TOLERANCE

The dimensional variations of a part characteristic of a specific process, once the setup is made.

  • PROGRESSIVE AGING

Aging by increasing the temperature in steps or continuously during the aging cycle. See aging and compare with interrupted aging and step aging.

  • PROGRESSIVE DIE

A die in which two or more sequential operations are performed at two or more positions, the work being moved from station to station.

  • PROGRESSIVE FORMING

Sequential forming at consecutive stations either with a single die or with separate dies.

  • PROJECTION WELDING

Resistance welding similar to spot welding, but in which the welds are localized at projections, embossments or intersections.

  • PROMPT (INDUSTRIAL) SCRAP

Excess steel that is trimmed by the auto and appliance stampers and auctioned to scrap buyers as factory bundles. This is a high-quality scrap as the result of its low-residual content and consistent chemistry

  • PROOF

Any reproduction of a die impression in any material, frequently a lead or plaster cast. See die proof.

  • PROOF LOAD

A predetermined load, generally some multiple of the service load, to which a specimen or structure is submitted before acceptance for use.

  • PROOF STRESS

(1) The stress that will cause a specified small permanent set in a material. (2) A specified stress to be applied to a member or structure to indicate its ability to withstand service loads.

  • PROPORTIONAL LIMIT

The maximum stress at which strain remains directly proportional to stress.

  • PSEUDOBINARY SYSTEM

(1) A three- component or ternary alloy system in which an intermediate phase acts as a component. (2) A vertical section through a ternary diagram.

  • PSEUDOCARBURIZING

See blank carburizing.

  • PSEUDONITRIDING

See blank nitriding.

  • PUCKERING

Wrinkling or buckling in a drawn shell in an area originally inside the draw ring.

  • PULL CRACKS

In a casting, cracks that are caused by residual stresses produced during cooling, and that result from the shape of the object.

  • PULSATION WELDING

Sometimes used as a synonym for multiple-impulse welding.

  • PULSED POWER WELDING

Any arc welding process in which the power is cyclically varied to give short duration pulses of either voltage or current that are significantly different from the average value.

  • PULVERIZATION

Synonymous with commmution.

  • PULVERIZED COAL INJECTION SYSTEM (PCI)

A blast furnace enhancement to reduce an integrated mill's reliance on coke (because of environmental problems with its production). Up to 30percent of the coke charged into the blast furnace can be replaced by this talcum-like coal powder, which is injected through nozzles at the bottom of the furnace

  • PUNCH

(1) The movable tool that forces material into the die in powder molding and most forming operations. (2) The movable die in a trimming press or a forging machine. (3) The tool that forces the stock through the die in rod and tube extrusion and forms the internal surface in can or cup extrusion.

  • PUNCH PRESS

(1) In general, any mechanical press. (2) In particular, an endwheel gap-frame press with a fixed bed, used in piercing.

  • PUNCH RADIUS

The radius on the end of the punch that first contacts the work, sometimes called nose radius.

  • PUNCHING

Producing a hole by die shearing, in which the shape of the hole is controlled by the shape of the punch and its mating die; piercing. Multiple punching of small holes is called perforating.

  • PUNCH-TO-DIE CLEARANCE

See die clearance.

  • PUSH ANGLE

The angle between a welding electrode and a line normal to the face of the weld when the electrode is pointing forward along the weld joint. See sketch accompanying forehand welding.

  • PUSH BENCH

Equipment used for drawing moderately heavy-gage tubes by cupping sheet and forcing it through a die by pressure exerted against the inside bottom of the cup.

  • PUSH FIT

A loosely defined fit similar to a snug fit.

  • PUSH WELDING

Spot or projection welding in which the force is applied manually to one electrode, and the work or a backing bar takes the place of the other electrode.

  • PUSHER FURNACE

A type of continuous furnace in which parts to be heated are periodically charged into the furnace in containers, which are pushed along the hearth against a line of previously charged containers thus advancing the containers toward the discharge end of the furnace, where they are removed.

  • PYRAMIDAL PLANE

In noncubic crystals, any plane that intersects all three axes.

  • PYROMETALLURGY

High-temperature winning or refining of metals.

  • PYROMETER

A device for measuring temperatures above the range of liquid thermometers.

  • Q-BOP

Modified Basic Oxygen Furnace in which the oxygen and other gases are blown in from the bottom, rather than from the top. While the Q-BOP stirs the metal bath more vigorously, allowing for faster processing, the design produces essentially the same steel grades as the top-blowing basic oxygen furnace. Today's state-of-the-art furnace design combines the previous technologies: 60percent of the oxygen is blown from above, with the rest blown through the bottom of the vessel

  • QUALIFICATION TRIALS

The testing required for a new process adopted to make certain grades of steel with exacting end uses. In order for the process to become qualified, the steel made by the process must be tested

  • QUALITY

(1) The totality of features and characteristics of a product or service that bear on its ability to satisfy a given need (fitness-for-use concept of quality). (2) Degree of excellence of a product or service (comparative concept). Often determined subjectively by comparison against an ideal standard or against similar products or services available from other sources (3) A quantitative evaluation of the features and characteristics of a product or service (quantitative concept).

  • QUALITY CHARACTERISTIC

Any dimension, mechanical property, physical property, functional characteristic or appearance characteristic that can be used as a basis for measuring the quality of a unit of product or service.

  • QUANTITATIVE METALLOGRAPHY

Determination of specific characteristics of a microstructure by making quantitative measurements on micrographs or metallographic images. Quantities so measured include volume concentration of phases, grain size, particle size, mean free path between like particles or secondary phases, and suface area to volume ratio of microconstituents, particles or grains.

  • QUARTER HARD

A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength about midway between that of dead soft and half hard tempers.

  • QUASIBINARY SYSTEM

In a ternary or higher-order system, a linear composition series between two substances each of which exhibits congruent melting, wherein all equilibriums, at all temperatures or pressures, involve only phases having compositions occurring in the linear series, so that the series may be represented as binary on a phase diagram.

  • QUENCH AGING

Aging induced by rapid cooling after solution heat treatment.

  • QUENCH ANNEALING

Annealing an austenitic ferrous alloy by solution heat treatment followed by rapid quenching.

  • QUENCH CRACKING

Fracture of a metal during quenching from elevated temperature. Most frequently observed in hardened carbon steel, alloy steel or tool steel parts of high hardness and low toughness. Cracks often emanate from fillets, holes, corners or other stress raisers and result from high stresses due to the volume changes accompanying transformation to martensite.

  • QUENCH HARDENING

(1) Hardening suitable alpha-beta alloys (most often certain copper or titanium alloys) by solution treating and quenching to develop a martensite-like structure. (2) In ferrous alloys, hardening by austenitizing and then cooling at a rate such that a substantial amount of austenite transforms to martensite.

  • QUENCH TIME

In resistance welding, the time from the finish of the weld to the beginning of temper. Also called chill time.

  • QUENCH-AGE EMBRITTLEMENT

Embrittlement of low-carbon steel evidenced a loss of ductility on aging at room temperature following rapid cooling from a temperature below the lower critical temperature.

  • QUENCHING

Rapid cooling. When applicable, the following more specific terms should be used: direct quenching, fog quenching, hot quenching, interrupted quenching, selective quenching, spray quenching and time quenching.

  • QUILL

(1) A hollow or tubular shaft, designed to slide or revolve, carrying a rotating member within itself. (2) Removable spindle projection for supporting a cutting tool or grinding wheel.

  • RABBLE

A hoelike bladed tool or similar device used for stirring molten metal.

  • RADIAL DRAW FORMING

Forming metals by the simultaneous application of tangential stretch and radial compression forces, the operation being done gradually by tangential contact to the die member. This type of forming is characterized by very close dimensional control.

  • RADIAL FORGING

A process utilizing two or more moving anvils or dies for producing shafts with constant or varying diameters along their length or tubes with internal or external variations in diameter; also known as draw forging or rotary swaying.

  • RADIAL MARKS

Lines on a fracture surface that radiate from the fracture origin and are visible to the unaided eye or at low magnification. Radial lines result from the intersection and connection of brittle fractures propagating at different levels. Also called shear ledges. See also chevron pattern.

  • RADIAL RAKE

The angle between the tooth face and a radial line passing through the cutting edge in a plane perpendicular to the cutter axis. See sketch accompanying face mill.

  • RADIAL RUNOUT

For any rotating element, the total variation from true radial position, taken in a plane perpendicular to the axis of rotation. Compare with axial runout.

  • RADIATION DAMAGE

A general term for the alteration of properties of a material arising from exposure to ionizing radiation (penetrating radiation) such as x-rays, gamma rays, neutrons, heavy-particle radiation, or fission fragments in nuclear fuel material.

  • RADIATION DOSE

Accumulated exposure to ionizing radiation during a specified period of time.

  • RADIATION ENERGY

The energy of a given photon or particle in a beam of radiation, often expressed in electron volts.

  • RADIATION GAGE

An instrument for measuring the intensity and quantity of ionizing radiation.

  • RADIATION INTENSITY

In general, the quantity of radiant energy at a specified location passing perpendicularly through unit area in unit time. It may be given as number of particles or photons per square centimetre per second, or in energy units as J/m2 s or Rhm.

  • RADIATION MONITORING

The continuous or periodic measurement of the intensity of radiation received by personnel or present in any particular area.

  • RADIATION QUALITY

A term describing roughly the spectrum of radiation produced by a radiation source, with respect to its penetrating power or its suitability for a given application.

  • RADIOACTIVE ELEMENT

An element that has at least one isotope that undergoes spontaneous nuclear disintegration to emit positive alpha particles, negative beta particles, or gamma rays.

  • RADIOACTIVE TRACER ELEMENT

A radioactive isotope of an element used to study the movement and behavior of atoms by observing the distribution and intensity of radioactivity.

  • RADIOACTIVITY

The spontaneous nuclear disintegration with emission of corpuscular or electromagnetic radiation.

  • RADIOGRAPH

A photographic shadow image resulting from uneven absorption of penetrating radiation in a test object.

  • RADIOGRAPHY

A method of nondestructive inspection in which a test object is exposed to a beam of x-rays or gamma rays and the resulting shadow image of the object is recorded on photographic film placed behind the object. Internal discontinuities are detected by observing and interpreting variations in the image caused by differences in thickness, density or absorption within the test object. Variations of radiography include electron radiography, fluoroscopy, neutron radiography.

  • RADIOISOTOPE

An isotope that emits ionizing radiation during its spontaneous decay.

  • RAKE

The angular relationship between the tooth face, or a tangent to the tooth face at a given point, and a given reference plane or line. See sketches accompanying face mill and single-point tool.

  • RAM

The moving member of a hammer, machine, or press to which a tool is fastened.

  • RAMMING

Packing sand, refractory or other material into a compact mass.

  • RAMOFF

A casting imperfection resulting from the movement of sand away from the pattern because of improper ramming.

  • RANDOM SEQUENCE

A longitudinal welding sequence where the weldbead increments are deposited at random to minimize distortion.

  • RANGE

In inspection, the difference between the highest and lowest values of a given quality characteristic within a single sample.

  • RARE EARTH METAL

One of the group of 15 chemically similar metals with atomic numbers 57 through 71, commonly referred to as the lanthanides.

  • RAT TAIL

A surface imperfection on a casting, occurring as one or more irregular lines, caused by expansion of sand in the mold. Compare with buckle (2).

  • RATCHET MARKS

Lines on a fatigue fracture surface that result from the intersection and connection of fatigue fractures propagating from multiple origins. Ratchet marks are parallel to the over-all direction of crack propagation and are visible to the unaided eye or at low magnification.

  • RATCHETING

Progressive cyclic inelastic deformation (growth, for example) that occurs when a component or structure is subjected to a cyclic secondary stress superimposed on a sustained primary stress. The process is called thermal ratcheting when cyclic strain is induced by cyclic changes in temperature, and isothermal ratcheting when cyclic strain is mechanical in origin (even though accompanied by cyclic changes in temperature).

  • RATE OF STRAIN HARDENING

Rate of change of true stress with respect to true strain in the plastic range.

  • RE

Abbreviation for rare earth (elements).

  • REAMED EXTRUSION INGOT

A cast hollow extrusion ingot that has been machined to remove the original inside surface.

  • REAMER

A rotary cutting tool with one or more cutting elements called teeth used for enlarging a hole to desired size and contour. It is supported principally by the metal around the hole it cuts.

  • RECALESCENCE

A phenomenon, associated with the transformation of gamma iron to alpha iron on the cooling (supercooling) of iron or steel, revealed by the brightening (reglowing) of the metal surface owing to the sudden increase in temperature caused by the fast liberation of the latent heat of transformation. Contrast with decalescence.

  • RECARBURIZE

(1) To increase the carbon content of molten cast iron or steel by adding carbonaceous material, high carbon pig iron or a high-carbon alloy. (2) To carburize a metal part to return surface carbon lost in processing; also known as carbon restoration.

  • RECESS

A groove or depression in a surface.

  • RECLAIM RINSE

A nonflowing rinse used to recover dragout.

  • RECOIL LINE

See impact line.

  • RECOVERY

(1) Reduction or removal of work-hardening effects, without motion of large-angle grain boundaries (2) The proportion of the desired component obtained by processing an ore usually expressed as a percentage.

  • RECRYSTALLIZATION

(1) The formation of a new, strain-free grain structure from that existing in cold worked metal, usually accomplished by heating. (2) The change from one crystal structure to another, as occurs on heating or cooling through a critical temperature.

  • RECRYSTALLIZATION ANNEALING

Annealing cold worked metal to produce a new grain structure without phase change.

  • RECRYSTALLIZATION TEMPERATURE

The approximate minimum temperature at which complete recrystallization of a cold worked metal occurs within a specified time.

  • RECUPERATOR

Equipment for transferring heat from gaseous products of combustion to incoming air or fuel. The incoming material passes through pipes surrounded by a chamber through which the outgoing gases pass.

  • RED MUD

A residue, containing a high percentage of iron oxide, obtained in purifying bauxite in the production of alumina in the Bayer process.

  • REDRAWING

Drawing metal after a previous cupping or drawing operation.

  • REDUCING AGENT

A substance that causes reduction. See reduction (3).

  • REDUCING AGENT

Either natural gas or coal can be used to remove the oxygen from iron ore in order to produce a scrap substitute. In gas-based processes, the iron ore is heated in a vessel as reformed natural gas passes through. In coal-based processes, iron ore is combined with gasified or ground coal and heated. The oxygen in the ore combines with carbon and hydrogen in the gas or coal, producing reduced, or metallic, iron

  • REDUCING FLAME

A gas flame produced with excess fuel in the inner flame.

  • REDUCTION

(1) In cupping and deep drawing, a measure of the percentage decrease from blank diameter to cup diameter, or of diameter reduction in redraws. (2) In forging, rolling and drawing, either the ratio of the original to final cross-sectional area or the percentage decrease in cross-sectional area. (3) A reaction in which there is a decrease in valence resulting from a gain in electrons. Contrast with oxidation.

  • REDUCTION CELL

A pot or tank in which either a water solution of a salt or a fused salt is reduced electrolytically to form free metals or other substances.

  • REDUCTION OF AREA

(1) Commonly, the difference, expressed as a percentage of original area, between the original cross-sectional area of a tensile test specimen and the minimum crosseectional area measured after complete separation. (2) The difference, expressed as a percentage of original area, between original crosssectional area and that after straining the specimen.

  • REEL

(1) A spool or hub for coiling or feeding wire or strip. (2) To straighten and planish a round bar by passing it between contoured rolls.

  • REEL BREAKS

Transverse breaks or ridges on successive inner laps of a coil that are the result of crimping the feat end of the coil into a gripping segmented mandrel. Also called reel kinks.

  • REFERENCE PLANE

(1) The plane that contains the cutter axis and the point of the cutting edge. See sketch accompanying face mill. (2) A plane from which measurements are made.

  • REFINING

The branch of process metallurgy dealing with the purification of crude or impure metals. Compare with extractive metallurgy.

  • REFLECTOR SHEET

A clad product, containing a facing layer of high-purity aluminum capable of taking a high polish for reflecting heat or light and a base of commercially pure aluminum or an aluminum-manganese alloy for strength and formability.

  • REFLOWING

The melting of an electrodeposit followed by solidification. The surface has the appearance and physical characteristics of being hot dipped (especially tin or tin alloy plates). Also called flow brightening.

  • REFRACTORY

(1) A material of very high melting point with properties that make it suitable for such uses as furnace linings and kiln construction. (2) The quality of resisting heat.

  • REFRACTORY ALLOY

(1) A heat-resistant alloy. (2) An alloy having an extremely high melting point. See refractory metal. (3) An alloy difficult to work at elevated temperatures.

  • REFRACTORY BRICK

Heat-resistant brick. Because its melting point is well above the operating temperatures of the process, refractory bricks line most steelmaking vessels that come in contact with molten metal, like the walls of the blast furnace, sides of the ladles, and inside of the BOF

  • REFRACTORY METAL

A metal having an extremely high melting point; for example, tungsten, molybdenum, tantalum, niobium (columbium), chromium, vanadium and rhenium. In the broad sense, it refers to metals having melting points above the range of iron, cobalt and nickel.

  • REGENERATOR

Same as recuperator except the gaseous products of combustion heat brick checkerwork in a chamber connected to the exhaust side of the furnace while the incoming air and fuel are being heated by the brick checkerwork in a second chamber, connected to the entrance side. At intervals, the gas flow is reversed so that incoming air and fuel contact hot checkerwork while that in the second chamber is being reheated by exhaust gases.

  • REINFORCING BAR (REBAR)

A commodity-grade steel used to strengthen concrete in highway and building construction

  • REJECTABLE

See preferred term, nonconforming.

  • RELIABILITY

A quantitative measure of the ability of a product or service to fulfill its intended function for a specified period of time.

  • RELIEF ANGLE

The angle formed between a relieved surface and a given plane tangent to a cutting edge or to a point on a cutting edge. See sketch accompanying single-point tool.

  • RELIEVING

Buffing or other abrasive treatment of the high points of an embossed metal surface to produce highlights that contrast to the finish in the recesses.

  • RELINE

The process of replacing the refractory lining of a liquid steel vessel. Once it wears out, the brick lining of a furnace must be cooled, stripped and replaced. This maintenance can be significant because a blast furnace reline may require up to three months to complete

  • REMANENCE

The magnetic induction remaining in a magnetic circuit after removal of the applied magnetizing force. Sometimes called remanent induction.

  • RE-PRESSING

The application of pressure to a previously pressed and sintered powder metallurgy compact, usually for the purpose of improving some physical property.

  • RESIDUAL ELEMENTS

Elements present in an alloy in small quantities, but not added intentionally.

  • RESIDUAL FIELD

Same as residual magnetic field.

  • RESIDUAL MAGNETIC FIELD

The magnetic field that remains in a part after the magnetizing force is removed.

  • RESIDUAL METHOD

Method of magnetic particle inspection in which the particles are applied after the magnetizing force has been removed.

  • RESIDUAL STRESS

Stress present in a body that is free of external forces or thermal gradients.

  • RESIDUALS

The impurities in mini-mill steel as the result of the mix of metals entering the process dissolved in obsolete scrap. Residuals are key concerns regarding the mini mills' recent entry into the flat-rolled market, where high residuals can leave sheet steel too brittle for customer use

  • RESILIENCE

(1) The amount of energy per unit volume released upon unloading. (2) The capacity of a metal by virtue of high yield strength and low elastic modulus, to exhibit considerable elastic recovery upon release of load.

  • RESINOID WHEEL

A grinding wheel bonded with a synthetic resin.

  • RESIST

(1) A material applied to a part of a cathode or plating rack to render the surface nonconductive. (2) A material applied to a part of the surface of an article to prevent reaction of metal from that area during chemical or electrochemical processes. (3) A material applied to prevent the flow of brazing filler metal into unwanted areas.

  • RESISTANCE BRAZING

Brazing by resistance heating, the joint being part of the electrical circuit.

  • RESISTANCE SOLDERING

Soldering in which the joint is heated by electrical resistance. Filler metal is either face fed into the joint or preplaced in the joint.

  • RESISTANCE WELDING

Welding with resistance heating and pressure, the work being part of the electrical circuit. Examples: resistance spot welding, resistance seam welding, projection welding and flash butt welding.

  • RESISTANCE WELDING DIE

The part of a resistance welding machine, usually shaped to the work contour, with which the parts being welded are held and which conducts the welding current.

  • RESOLUTION

The ability to separate closely related items of data or physical features using a given test method; also a quantitative measure of the degree to which they can be discriminated.

  • RESTRAINT

Any external mechanical force that prevents a part from moving to accommodate changes in dimensions due to thermal expansion or contraction. Often applied to weldments made while clamped in a fixture. Compare with constraint.

  • RESTRIKING

(1) Striking a trimmed but slightly misaligned or otherwise faulty forging one or more blows to improve alignment, improve surface, maintain close tolerance, increase hardness or effect other improvements. (2) A sizing operation in which coining or stretching is utilized to correct or alter profiles and to counteract distortion.

  • RESULTANT RAKE

The angle between the tooth face and an axial plane through the tooth point measured in a plane perpendicular to the cutting edge. The resultant rake of a cutter is a function of three other angles: radial rake, axial rake and corner angle. See sketch accompanying face mill.

  • RETENTIVITY

The capacity of a material to retain a portion of the magnetic field set up in it after the magnetizing force has been removed.

  • RETORT

A vessel used for the distillation of volatile materials, as in the separation of some metals and in the destructive distillation of coal.

  • REVERBERATORY FURNACE

A furnace, with a shallow hearth, usually nonregenerative, having a roof that deflects the flame and radiates heat toward the hearth or the surface of the charge.

  • REVERSE DRAWING

Redrawing in a direction opposite to that of the original drawing.

  • REVERSE FLANGE

A flange made by shrinking, as opposed to one formed by stretching.

  • REVERSE POLARITY

Direct-current arc welding circuit arrangement in which the electrode is connected to the positive terminal. Contrast with straight polarity.

  • REVERSE REDRAWING

A second drawing operation in a direction opposite to that of the original drawing.

  • REVERSE-CURRENT CLEANING

Same as anodic cleaning.

  • REVERSING MILL

The stand of rolls used to reduce steel sheet or plate by passing the steel back and forth between the rolls; the gap between the rolls is reduced after each pass

  • RHEOLOGY

The science of deformation and flow of matter.

  • RHEOTROPIC BRITTLENESS

That portion of the brittleness characteristic of non-face-centered cubic metals, when tested in the presence of a stress concentration or at low temperatures or at high strain rates, that may be eliminated by prestraining under milder conditions.

  • RIDDLE

A sieve used to separate foundry sand or other granular materials into various particle-size grades or to free such a material of undesirable foreign matter.

  • RIGGING

The engineering design, layout and fabrication of pattern equipment for producing castings; including a study of the casting solidification program, feeding and gating, risering, skimmers and fitting flasks.

  • RIGHT-HAND CUTTING TOOL

A cutter all of whose flutes twist away in a clockwise direction when viewed from either end.

  • RIMMED STEEL

A low-carbon steel containing sufficient iron oxide to give a continuous evolution of carbon monoxide while the ingot is solidifying, resulting in a case or rim of metal virtually free of voids. Sheet and strip products made from the ingot have very good surface quality.

  • RING AND CIRCLE SHEAR

A cutting or shearing machine with two rotary disk cutters driven in unison and equipped with a circle attachment for cutting inside circles or rings from sheet metal, where it is impossible to start the cut at the edge of the sheet. One cutter shaft is inclined to the other to provide cutting clearance so that the outside section remains flat and usable. See circle shear.

  • RING ROLLING

The process of shaping weldless rings from pierced disk or thick-walled, ring-shaped blanks between rolls that control wall thickness, ring diameter, height and contour.

  • RINGING

The audible or ultrasonic tone produced in a mechanical part by shock, and having the natural frequency or frequencies of the part. The quality, amplitude or decay rate of the tone may sometimes be used to indicate quality or soundness. See also sonic testing, ultrasonic testing.

  • RINSABILITY

The relative ease of removing a substance from a metal surface with a liquid such as water.

  • RISER

A reservoir of molten metal connected to the casting to provide additional metal to the casting, required as the result of shrinkage before and during solidification.

  • RIVETING

Joining of two or more members of a structure by means of metal rivets, the unheeded end being upset after the rivet is in place.

  • ROASTING

Heating an ore to effect some chemical change that will facilitate smelting.

  • ROBBER

An extra cathode or cathode extension that reduces the current density on what would otherwise be a high-current-density area on work being electroplated.

  • ROCHELLE COPPER

(1) A copper electrodeposit obtained from copper cyanide plating solution to which Rochelle salt (sodium potassium tartrate) has been added for grain refinement, better anode corrosion and cathode effficiency. (2) The solution from which a Rochelle copper electrodeposit is obtained.

  • ROCK CANDY FRACTURE

A fracture that exhibits separated-grain facets, most often used to describe intergranular fractures in large-grained metals.

  • ROCKING SHEAR

A type of guillotine shear that utilizes a curved blade to shear sheet metal progressively from side to side by a rocker motion.

  • ROCKRITE TUBE-REDUCING PROCESS

See tube reducing.

  • ROCKWELL HARDNESS TEST

An indentation hardness test based on the depth of penetration of a specified penetrator into the specimen under certain arbitrarily fixed conditions.

  • ROD

Round, thin semi-finished steel length that is rolled from a billet and coiled for further processing. Rod is commonly drawn into wire products or used to make bolts and nails. Rod trains (rolling facilities) can run as fast as 20.000 feet per minute - more than 200 miles an hour

  • ROD MILL

(1) A hot mill for rolling rod. (2) A mill for fine grinding, somewhat similar to a ball mill, but employing long steel rods instead of balls to effect the grinding.

  • ROLL BENDING

Curving sheets, bars and sections by means of rolls. See bending rolls.

  • ROLL COMPACTING

The progressive compacting of metal powders by the use of a rolling mill.

  • ROLL FLATTENING

Flattening of sheets that have been rolled in packs by passing them separately through a two high cold mill, there being virtually no deformation. Not to be confused with roller leveling.

  • ROLL FORCE SYSTEMS

Mill stands place considerable pressure on slabs, blooms and coils to further process the material. There are two general ways of applying the force to the steel - screw and hydraulic systems

  • ROLL FORGING

Forging with rotating dies that are not full round, the desired shape - either straight or tapered - being produced by a groove in the dies.

  • ROLL FORMING

Forming of flat-rolled metal by use of power-driven rolls whose contour determines the shape of the product. Roll forming is used extensively to make metal window frames, drapery rods and similar products from metal strip. The term is sometimes used to describe power spinning.

  • ROLL RESISTANCE SPOT WELDING

The making of separated resistance spot welds with one or more rotating circular electrodes. The rotation of the electrodes may or may not be stopped during the making of a weld.

  • ROLL STRAIGHTENING

Straightening of metal stock of various shapes by (1) passing it through a series of staggered rolls, the rolls usually being in horizontal and vertical planes; or (2) by reeling in two-roll straightening machines.

  • ROLL TABLE

A conveyor table where rolls furnish the contact surface.

  • ROLL THREADING

Making threads by rolling the piece between two grooved die plates, one of which is in motion, or between rotating grooved circular rolls.

  • ROLL WELDING

Solid state welding in which metals are heated, then welded together by applying pressure, with rolls, sufficient to cause deformation at the faying surfaces. See also forge welding.

  • ROLLED GOLD

Same as gold filled except that the proportion of gold alloy to the weight of the entire article may be less than 1/20th. Fineness of the gold alloy may not be less than 10K.

  • ROLLER LEVELER BREAKS

Obvious transverse breaks usually about 3 to 6 mm (1/8 to 1/4 in.) apart caused by the sheet fluting during roller leveling. These will not be removed by stretching.

  • ROLLER LEVELER LINES

Same as leveler lines.

  • ROLLER LEVELING

Leveling by passing flat stock through a machine having a series of small-diameter staggered rolls that are adjusted to produce repeated reverse bending.

  • ROLLER STAMPING DIE

An engraved roller used for impressing designs and markings on sheet metal.

  • ROLLING

Reducing the cross-sectional area of metal stock, or otherwise shaping metal products, through the use of rotating rolls.

  • ROLLING MILLS

Machines used to decrease the cross-sectional area of metal stock and produce certain desired shapes as the metal passes between rotating rolls mounted in a framework comprising a basic unit called a stand. Cylindrical rolls produce flat shapes; grooved rolls produce rounds, squares and structural shapes. Among rolling mills may be listed the billet mill, blooming mill, breakdown mill, plate mill, sheet mill, slabbing mill, strip mill and temper mill.

  • ROOT CRACK

A crack in either the weld or heat-affected zone at the root of a weld.

  • ROOT FACE

The portion of a weld groove face adjacent to the root of the joint.

  • ROOT OF JOINT

The portion of a weld joint where the members are closest to each other before welding. In cross section, may be a point, a line or an area.

  • ROOT OF WELD

The points, as shown in cross section, at which the weld bead intersects the base metal surfaces either nearest to or coincident with the root of joint.

  • ROOT OPENING

In a weldment, the separation between the members at the root of joint prior to welding.

  • ROOT PASS

The first bead of a multiplepass weld, laid in the root of joint.

  • ROOT PENETRATION

The depth that a weld extends into the root of joint measured on the centerline of the root cross section. See sketch accompanying joint penetration.

  • ROSEBUDS

Concentric rings of distorted coating, giving the effect of an opened rosebud. Noted only on minimized spangle.

  • ROSETTE

(1) Rounded configuration of microconstituents arranged in whorls or radiating from a center. (2) Strain gages arranged to indicate at a single position strains in three different directions.

  • ROTARY FORGING

A process subjecting the workpiece to pressing between a flat anvil and a swiveling die with a conical working face; the platens move toward each other during forging.

  • ROTARY FURNACE

A circular furnace constructed so that the hearth and workpieces rotate around the axis of the furnace during heating.

  • ROTARY SHEAR

A sheet-metal-cutting machine with two rotating-disk cutters mounted on parallel shafts driven in unison.

  • ROTARY SWAGER

A swaying machine consisting of a power-driven ring that revolves at high speed causing rollers to engage cam surfaces and force the dies to deliver hammerlike blow, upon the work at high frequency Both straight and tapered section' can be produced.

  • ROUGE FINISH

A highly reflective finish produced with rouge or other very, fine abrasive, similar in appearance to the bright polish or mirror finish on sterling silver utensils.

  • ROUGH GRINDING

Grinding without regard to finish, usually to be followed by a subsequent operation.

  • ROUGH MACHINING

Machining without regard to finish, usually to be followed by a subsequent operation.

  • ROUGHING STAND

The first stand of roll through which the reheated billet passes, or the last stand in front of the finishing rolls.

  • ROUGHNESS

Relatively finely spaced surface irregularities, the height, width and direction of which establish the predominant surface pattern.

  • ROUGHNESS-WIDTH CUTOFF

The maximum width in inches of surface irregularities to be included in the measurement of roughness height.

  • RUB MARK (SEE ABRASION RUNNER)

(1) A channel through which molten metal flows from one receptacle to another. (2) The portion of the gate assembly of a casting that connects the sprue with the gate(s). (3) Parts of patterns and finished castings corresponding to the portion of the gate assembly described in (2).

  • RUBBER BLANKET

A sheet of rubber or other resilient material used as an auxiliary tool in forming.

  • RUBBER FORMING

Forming where rubber or other resilient material is used as a functional die part. Processes in which rubber is employed only to contain the hydraulic fluid are not classified as rubber forming.

  • RUBBER WHEEL

A grinding wheel made with a rubber bond.

  • RUBBER-PAD FORMING

A forming operation for shallow parts where a rubber pad or other resilient material is attached to the press slide and becomes the mating die for a punch, or group of punches, that has been placed on the press bed or plate. Also known as the Guerin process.

  • RUNNER BOX

A distribution box that divides molten metal into several streams before it enters the mold cavity.

  • RUNNING FIT

Any clearance fit in the range used for parts that rotate relative to each other. Actual values of clearance resulting from stated shaft and hole tolerances are given in ANSI standards.

  • RUNOUT

(1) The unintentional escape of molten metal from a mold, crucible or furnace. (2) An imperfection in a casting caused by the escape of metal from the mold. (3) See axial runout and radial runout.

  • RUNOUT TABLE

A roll table used to receive a rolled or extruded section.

  • RUST

A corrosion product consisting of hydrated oxides of iron. Applied only to ferrous alloys.

  • SACRIFICIAL PROTECTION

Reducing the extent of corrosion of a metal in an electrolyte by coupling it to another metal that is electrochemically more active in the environment.

  • SADDLING

Forming a seamless ring by forging a pierced disk over a mandrel (or saddle).

  • SAG

An increase or decrease in the section thickness of a casting caused by insufficient strength of the mold sand of the cope or of the core.

  • SALT FOG TEST

An accelerated corrosion test in which specimens are exposed to a fine mist of a solution usually containing sodium chloride but sometimes modified with other chemicals. For testing details see ASTM B117.

  • SALT SPRAY TEST

More properly, salt fog test.

  • SALTING OUT

Precipitating a substance in a solution by adding a second substance, usually a salt, without any chemical reaction such as a double decomposition taking place.

  • SAMPLE

One or more units of product (or a relatively small quantity of a bulk material) that is withdrawn from a lot or process stream, and that is tested or inspected to provide information about the properties, dimensions or other quality characteristics of the lot or process stream. Not to be confused with specimen.

  • SAND

A granular material, naturally or artificially produced by the disintegration or crushing of rocks or mineral deposits. In casting, the term denotes an aggregate whose individual particle (grain) size is 0.06 to 2mm (1/400 to 1/12 in.) in diameter, and largely free of finer constituents such as silt and clay, which are often present in natural sand deposits. The most commonly used foundry sand is silica; however, zircon, olivine, chromite, alumina and other crushed ceramics are used for special applications.

  • SAND BLASTING

Abrasive blasting with sand. See blasting, and compare with shot blasting.

  • SAND CONTROL

Testing and regulation of the chemical, physical and mechanical properties of foundry sand mixtures and their components.

  • SAND HOLE

A pit in the surface of a sand casting resulting from a deposit of loose sand in the mold cavity.

  • SANDWICH ROLLING

Rolling two or more strips of metal in a pack, sometimes to form a roll-welded composite.

  • SAPONIFICATION

The alkaline hydrolysis of fats whereby a soap is formed; more generally, the hydrolysis of an ester by an alkali with the formation of an alcohol and a salt of the acid portion.

  • SATIN FINISH

A diffusely reflecting surface finish on metals, lustrous but not mirrorlike. One type is a butler finish.

  • SAW GUMMING

In saw manufacture, the grinding away of punch marks or milling marks in the gullets (spaces between the teeth), and in some cases simultaneous sharpening of the teeth; in reconditioning worn saws, restoration of the original gullet size and shape.

  • SCAB

An imperfection consisting of a thin, flat piece of metal attached to the surface of a sand casting. A sand scab usually is separated from the casting proper by a thin layer of sand and is joined to the casting along one edge. An erosion scab is similar in appearance to a cut or wash.

  • SCALE

The oxide of iron that forms on the surface of steel after heating

  • SCALE PIT

(1) A surface depression formed on a forging due to scale remaining in the dies during the forging operation. (2) A pit in the ground in which scale (such as that carried off by cooling water from rolling mills) is allowed to settle out as one step in the treatment of effluent waste water.

  • SCALING

(1) Forming a thick layer of oxidation products on metals at high temperature. (2) Depositing water insoluble constituents on a metal surface, as in cooling tubes and water boilers.

  • SCALPED EXTRUSION INGOT

A cast, solid or hollow extrusion ingot that has been machined on the outside surface.

  • SCALPING

Removing surface layers from ingots, billets or slabs. See die scalping.

  • SCARF JOINT

A butt joint in which the plane of the joint is inclined with respect to the main axis of the members.

  • SCARFING

Cutting surface areas of metal objects, ordinarily by using an oxyfuel gas torch. The operation permits surface imperfections to be cut from ingots, billets or the edges of plate that are to be beveled for butt welding. See chipping.

  • SCLEROSCOPE TEST

A hardness test where the loss in kinetic energy of a falling metal "tup", absorbed by indentation upon impact of the tup on the metal being tested, is indicated by the height of rebound.

  • SCORIFICATION

The oxidation, in the presence of fluxes, of molten lead containing precious metals to partly remove the lead in order to concentrate the precious metals.

  • SCOURING

(1) A wet or dry cleaning process involving mechanical scrubbing. (2) A wet or dry mechanical finishing operation using fine abrasive and low pressure by hand or with a cloth or wire wheel to produce satin or butler-type finishes.

  • SCRAP

(1) Products that are discarded because they are defective or otherwise unsuitable for sale. (2) Discarded metallic material, from whatever source, that may be reclaimed through melting and refining.

  • SCRAP (FERROUS)

Ferrous (iron containing) material that generally is remelted and recast into new steel. Integrated steel mills use scrap for up to 25percent of their basic oxygen furnace charge; 100percent of the mini-mills' raw material for their electric furnaces generally is scrap

  • SCRAP SUBSTITUTE

Raw material that can be charged in place of scrap in electric arc furnaces and basic oxygen furnaces. Scrap substitutes include, among others, DRI, HBI, iron carbide, and pig iron

  • SCRATCH HARDNESS

The hardness of a metal determined by the width of a scratch made by a cutting point drawn across the surface under a given pressure.

  • SCREEN

(1) One of a set of sieves, designated by the size of the openings, used to classify granular aggregates such as sand, ore or coke by particle size. (2) A perforated sheet placed in the gating system of a mold to separate dirt from the molten metal.

  • SCREW (INCLINE PLANE)

This older method used the basic principle of the screw to adjust the space between the mill rolls. Because metal touches metal, these configurations will wear down over time and can cause quality problems

  • SCREW DISLOCATION

See dislocation.

  • SCREW PRESS

A press whose slide is operated by a screw rather than by a crank or other means.

  • SCREW STOCK

Free-machining bar, rod or wire.

  • SCRUFF

A mixture of tin oxide and iron tin alloy formed as dross on a tin-coating bath.

  • SCUFFING

A form of adhesive wear that produces superficial scratches or a high polish on the rubbing surfaces. It is observed most often on inadequately lubricated parts.

  • SEA COAL

Finely ground coal, used as an ingredient in molding sands.

  • SEAL WELD

Any weld used primarily to obtain tightness and prevent leakage.

  • SEALING

(1) Closing pores in anodic coatings to render them less absorbent. (2) Plugging leaks in a casting by introducing thermosetting plastics into porous areas and subsequently setting the plastic with heat.

  • SEAM

(1) On the surface of metal, an unwelded fold or lap that appears as a crack, usually resulting from a discontinuity obtained in casting or in workpiece.

  • SEAMLESS PIPE

Pipe made from a solid billet, which is heated, then rotated under extreme pressure. This rotational pressure creates an opening in the center of the billet, which is then shaped by a mandrel to form pipe

  • SECONDARY STEEL

Steel that does not meet the original customer's specifications because of a defect in its chemistry, gauge or surface quality. Mills must search to find another customer (that can accept the lower quality) to take the off-spec steel at a discount. While secondary will not affect the reported yield, margins will suffer

  • SELECTIVE HEATING

Intentionally heating only certain portions of a workpiece.

  • SELECTIVE LEACHING

Corrosion in which one element is preferentially removed from an alloy, leaving a residue (often porous) of the elements that are more resistant to the particular environment. See also decarburization, denickelification, dezincification, graphitic corrosion.

  • SELECTIVE QUENCHING

Quenching only certain portions of an object.

  • SELF-DIFFUSION

Thermally activated movement of an atom to a new site in a crystal of its own species, as, for example, a copper atom within a crystal of copper.

  • SELF-HARDENING STEEL

See preferred term, air-hardening steel.

  • SEMI FINISHED STEEL

Steel shapes - for example, blooms, billets or slabs - that later are rolled into finished products such as beams, bars or sheet

  • SEMIAUTOMATIC PLATING

Plating in which prepared cathodes are mechanically conveyed through the plating baths, with intervening manual transfers.

  • SEMICONDUCTOR

An electronic conductor whose resistivity at room temperature is in the range of 10-7 to 1 ( m and in which the conductivity increases with increasing temperature over some temperature range.

  • SEMIFINISHER

An impression in a forging die that only approximates the finish dimensions of the forging. Semifinishers are often used to extend die life of the finishing impression, ensure proper control of grain flow during forging, and assist in obtaining desired tolerances. Also called semifinishing impression.

  • SEMIFINISHING

Preliminary operations performed prior to finishing.

  • SEMIKILLED STEEL

Steel that is incompletely deoxidized and contains sufficient dissolved oxygen to react with the carbon to form carbon monoxide to offset solidification shrinkage.

  • SEMIPERMANENT MOLD

A permanent mold in which sand cores are used.

  • SENDZIMIR MILL

A type of cluster mill with small-diameter working rolls, larger-diameter backup rolls, backed up by bearings on a shaft mounted eccentrically so that it can be rotated to increase the pressure between the bearings and backup rolls.

  • SENDZIMIR MILL (Z-MILL)

WHAT. Compact mill used for rolling cold coils of stainless steel in order to make the steel thinner, smoother, and stronger. WHY. To control the thickness of steel better at lower capital cost, and to roll thinner sheets and strips. HOW. Stainless steel sheet or strip passes between a matching pair of small work rolls with extremely smooth surfaces, heavily reinforced by clusters of back-up rolls. The rolls reduce the steel to the desired thickness

  • SENSITIVITY

The smallest difference in values that can be detected reliably with a given measuring instrument.

  • SENSITIZATION

In austenitic stainless steels, the precipitation of chromium carbides, usually at grain boundaries, upon exposure to temperatures of about 550 to 850 �C (1000 to 1550 �F), leaving the grain boundaries depleted of chromium and therefore susceptible to preferential attack by a corroding (oxidizing) medium.

  • SEQUENCE TIMER

In resistance welding, a device used for controlling the sequence and duration of any or all of the elements of a complete welding cycle except weld time or heat time.

  • SEQUENCE WELD TIMER

Same as sequence timer except either weld time or heat time, or both, are also controlled.

  • SEQUESTERING AGENT

A material that combines with metallic ions to form water-soluble complex compounds.

  • SERIES WELDING

Making two or more resistance spot, seam or projection welds simultaneously by a single welding transformer with three or more electrodes forming a series circuit.

  • SERVICE CENTER

A catchall name for an operation that buys steel, often processes it in some way and then sells it in a slightly different form. A service center is distinguished from an end-user by the fact that, unlike an end-user, a service center sells steel, not a fabricated product. Service centers are manufacturers to the extent that they add labor to steel by providing a service

  • SET

The shape of the solidifying surface of a metal, especially copper, with respect to concavity or convexity. May also be called pitch.

  • SET COPPER

An intermediate copper product containing about 3.5percent cuprous oxide, obtained at the end of the oxidizing portion of the fire-refining cycle.

  • SETTLING

(1) Separation of solids from suspension in a fluid of lower density solely because of gravitational effects. (2) A process for removing iron from liquid magnesium alloys by holding the melt at a low temperature after manganese has been added to it.

  • SHADOWING

(1) Same as shielding in electroplating. (2) Directional deposition of carbon or a metallic film on a plastic replica to highlight features to be analyzed by transmission electron microscopy.

  • SHAKEOUT

Removing castings from a sand mold.

  • SHANK

(1) The handle for carrying a small ladle or crucible. (2) The portion of a die, tool or forging by which it is held. (3) The main body of a lathe tool. If the tool is an inserted type, the shank is the portion that supports the insert. See sketch accompanying single-point tool.

  • SHAPE CORRECTING

Rolling, heating and quenching steel sheets often affect the dimensions of the steel. Levelers, temper mills and edge trimmers rework the processed steel to match customer specifications

  • SHAPING

Producing flat surfaces using single-point tools. The work is held in a vise or fixture, or clamped directly to the table. The ram supporting the tool is reciprocated in a linear motion past the work.

  • SHATTER CRACKS

Same as flakes.

  • SHAVING

(1) As a finishing operation, the accurate removal of a thin layer of a work surface by straight-line motion between a cutter and the surface. (2) Trimming parts such as stampings, forgings and tubes to remove uneven sheared edges or to improve accuracy.

  • SHEAR

(1) That type of force that causes or tends to cause two contiguous parts of the same body to slide relative to each other in a direction parallel to their plane of contact. (2) A type of cutting tool with which a material in the form of wire, sheet, plate or rod is cut between two opposing blades. (3) The type of cutting action produced by rake so that the direction of chip flow is other than at right angles to the cutting edge.

  • SHEAR ANGLE

The angle that the shear plane, in metal cutting, makes with the work surface.

  • SHEAR FRACTURE

A ductile fracture in which a crystal (or a polycrystalline mass) has separated by sliding or tearing under the action of shear stresses.

  • SHEAR LEDGES

See radial marks.

  • SHEAR LIP

A narrow, slanting ridge along the edge of a fracture surface. The term sometimes also denotes a narrow, often crescent-shaped, fibrous region at the edge of a fracture that is otherwise of the cleavage type, even though this fibrous region is in the same plane as the rest of the fracture surface.

  • SHEAR MODULUS

See modulus of elasticity.

  • SHEAR PLANE

A confined zone along which shear takes place in metal cutting. It extends from the cutting edge to the work surface.

  • SHEAR STRAIN

Same as shearing strain; see strain.

  • SHEAR STRENGTH

The stress required to produce fracture in the plane of cross section, the conditions of loading being such that the directions of force and of resistance are parallel and opposite although their paths are offset a specified minimum amount. The maximum load divided by the original cross-sectional area of a section separated by shear.

  • SHEAR STRESS

See stress.

  • SHEARING

If the edges of sheet and strip are not controlled during reduction, they must be trimmed parallel by shears. This process may be performed by either the steel or steel processor to match customer needs

  • SHEARING STRAIN

See strain.

  • SHEET

A flat-rolled metal product of some maximum thickness and minimum width arbitrarily dependent on the type of metal. It is thinner than plate, and has a width-to-thickness ratio greater than about 50.

  • SHEET SEPARATION

In spot, seam or projection welding, the gap that exists between faying surfaces surrounding the weld, after the joint has been welded.

  • SHEET STEEL

Thin, flat-rolled steel. Coiled sheet steel accounts for nearly one-half of all steel shipped domestically and is created in a hot-strip mill by rolling a cast slab flat while maintaining the side dimensions. The malleable steel lengthens to several hundred feet as it is squeezed by the rolling mill. The most common differences among steel bars, strip, plate, and sheet are merely their physical dimensions of width and gauge (thickness)

  • SHELF ROUGHNESS

Roughness on upward facing surfaces where undissolved solids have settled on parts during a plating operation.

  • SHELL

(1) A hollow structure or vessel. (2) An article formed by deep drawing. (3) The metal sleeve remaining when a billet is extruded with a dummy block of somewhat smaller diameter. (4) In shell molding, a hard layer of sand and thermosetting plastic or resin formed over a pattern and used as the mold wall. (5) A tubular casting used in making seamless drawn tube. (6) A pierced forging.

  • SHELL CORE

A shell-molded sand core.

  • SHELL HARDENING

A surface-hardening process in which a suitable steel workpiece, when heated through and quench hardened, develops a martensitic layer or shell that closely follows the contour of the piece and surrounds a core of essentially pearlitic transformation product. This result is accomplished by a proper balance among section size, steel hardenability, and severity of quench.

  • SHELL MOLDING

Forming a mold from thermosetting resin-bonded sand mixtures brought in contact with preheated (150 to 260 �C, or 300 to 500 �F) meter patterns, resulting in a firm shell with a cavity corresponding to the outline of the pattern. Also called Croning process.

  • SHIELDED METAL-ARC WELDING

Arc welding in which metals are fused together by heating them with an arc between a covered electrode and the work. Decomposition of the covering on the consumable electrode provide shielding gas, and the electrode itself provides the filler metal. Pressure is not applied to the joint.

  • SHIELDING

(1) A material barrier that prevents radiation or a flowing fluid from impinging on an object or a portion of an object. (2) Placing an object in an electrolytic bath so as to alter the current distribution on the cathode. A nonconductor is called shield; a conductor, a robber, thief, or guard.

  • SHIFT

A casting imperfection caused by mismatch of cope and drag or of core and mold.

  • SHOE

(1) A metal block used in a varies of bending operations to form or support the part being processed. (2) A anvil cap or sow block.

  • SHORE HARDNESS TEST

Same as Scleroscope test.

  • SHORT (NET) TON-2,000 POUNDS

Normal unit of statistical raw material input and steel output in the United States

  • SHORT CIRCUITING TRANSFER

In consumable-electrode arc welding, a type of metal transfer similar to globule transfer, but in which the drops are so large that the arc is short circuited momentarily during the transfer each drop to the weld puddle. Compare with spray transfer, globular transfer.

  • SHORT TRANSVERSE

See transverse.

  • SHORTS

The product that is retained on a specified screen in the screening of in crushed or ground material. See also plus sieve.

  • SHOT

Small spherical particles a metal.

  • SHOT BLASTING

Blasting with metal shot; usually used to remove deposit or mill scale more rapidly or more effectively than can be done by sand blasting.

  • SHOT PEENING

Cold working the surface of a metal by metal-shot impingement.

  • SHOTTING

The production of shot by pouring molten metal in finely divided streams. Solidified spherical particles are formed during the de scent and are cooled in a tank of water.

  • SHREDDED SCRAP

Fist-sized, homogenous pieces of old automobile hulks. After cars are sent through a shredder, the recyclable steel is separated by magnets. Mini-mills consume shredded scrap in their electric arc furnace operations

  • SHRINK FIT

An interference fit produced by heating the outside member to a practical temperature to assemble easily. Usually the inside member is kept at or near room temperature. Sometimes the inside member is cooled to increase the ease of assembly.

  • SHRINKAGE

See casting shrinkage.

  • SHRINKAGE CAVITY

A void left in cast metals as a result of solidification shrinkage. See casting shrinkage.

  • SHRINKAGE CRACKS

Hot tears associated with shrinkage cavities.

  • SHRINKAGE RULE

A measuring ruler with graduations expanded to compensate for the change in the dimensions of the solidified casting as it cools in the mold.

  • SHUT HEIGHT

For a press, the distance from the top of the bed to the bottom of the slide with the stroke down and adjustment up. In general it is the maximum die height that can be accommodated for normal operation taking the bolster plate into consideration.

  • SIDE CUTTING-EDGE ANGLE

Defined by sketch accompanying single-point tool.

  • SIDE MILLING

Milling with cutters having peripheral and side teeth. They are usually profile sharpened but may be form relieved.

  • SIDE RAKE

In a single-point turning tool, the angle between the tool face and a reference plane, corresponding to radial rake in milling. It lies in a plane perpendicular to the tool base and parallel to the rotational axis of the work. See sketch accompanying single-point tool.

  • SIDE RELIEF ANGLE

Defined by sketch accompanying single-point tool.

  • SIEVE ANALYSIS

Particle size distribution; usually expressed as the weight percentage retained upon each of a series of standard sieves of decreasing size and the percentage passed by the sieve of finest size. Synonymous with sieve classification.

  • SIEVE CLASSIFICATION

Same as sieve analysis.

  • SIEVE FRACTION

The portion of a powder sample that passes through a standard sieve of specified number and is retained by some finer sieve of specified number.

  • SIGMA PHASE

A hard, brittle nonmagnetic intermediate phase with a tetragonal crystal structure, containing 30 atoms per unit cell, space group P42/mnm, occurring in many binary and ternary alloys of the transition elements. The composition of this phase in the various systems is not the same and the phase usually exhibits a wide range in homogeneity. Alloying with a third transition element usually enlarges the field of homogeneity and extends it deep into the ternary section.

  • SILICA FLOUR

A sand additive, containing about 99.5percent silica, commonly produced by pulverizing quartz sand in large ball mills to a mesh size of 80 to 325.

  • SILICON ELECTRICAL STEEL

A type of specialty steel created by introducing silicon during the steelmaking process. Electrical steel exhibits certain magnetic properties, which make it optimum for use in transformers, power generators and electric motors

  • SILKY FRACTURE

A metal fracture in which the broken metal surface has a fine texture, usually dull in appearance. Characteristic of tough and strong metals. Contrast with crystalline fracture, granular fracture.

  • SILVER SOLDERING

Nonpreferred term used to denote brazing with a silverbase filler metal. See preferred terms furnace brazing, induction brazing, and torch brazing.

  • SINGLE WELDED JOINT

In arc and gas welding, any joint welded from one side only.

  • SINGLE-BEVEL GROOVE WELD

A groove weld in which the joint edge of one member is beveled from one side.

  • SINGLE-IMPULSE WELDING

Spot, projection or upset welding by a single impulse of current. Where alternating current is used, an impulse may be any fraction or number of cycles.

  • SINGLE-J GROOVE WELD

A groove weld in which the joint edge of one member is prepared in the form of a J, from one side. See sketch.

  • SINGLE-POINT TOOL

See definition of nomenclature in accompanying sketch.

  • SINGLE-STAND MILL

A rolling mill of such design that the product contacts only two rolls at a given moment. Contrast with tandem mill.

  • SINGLE-U GROOVE WELD

A groove weld in which each joint edge is prepared in the form of a J or half-U from one side. See sketch.

  • SINGLE-V GROOVE WELD

A groove weld in which each member is beveled from the same side. See sketch below

  • SINKHEAD

Same as riser.

  • SINKING

See tube sinking.

  • SINTER

To heat a mass of fine particles for a prolonged time below the melting point, usually to cause agglomeration.

  • SINTER

Baked particles that stick together in roughly one-inch chunks. Normally used for iron ore dust collected from the blast furnaces

  • SINTERING

The bonding of adjacent surfaces in a mass of particles by molecular or atomic attraction on heating at high temperatures below the melting temperature of any constituent in the material. Sintering strengthens a powder mass and normally produces densification and, in powdered metals, recrystallization. See also liquid phase sintering.

  • SINTERING

A process that combines iron-bearing particles, once recovered from environment control filters, into small pellets. Previously, these materials were too fine to withstand the air currents of the smelting process and were thrown away. The fro is now conserved because the chunks can be charged into the blast furnace (see Agglomerating Processes)

  • SIZE EFFECT

Effect of the dimensions of a piece of metal upon its mechanical and other properties and upon manufacturing variables such as forging reduction and heat treatment. In general, the mechanical properties are lower for a larger size.

  • SIZE OF WELD

(1) The joint penetration in a groove weld. (2) The lengths of the nominal legs of a fillet weld.

  • SIZING

(1) Secondary forming or squeezing operations, required to square up, set down, flatten or otherwise correct surfaces to produce specified dimensions and tolerances. See restriking (2) Some burnishing, broaching, drawing and shaving operations are also called sizing. (3) A finishing operation for correcting ovality in tubing. (4) Final pressing of a sintered powder metallurgy part.

  • SKELP

The starting stock for making welded pipe or tubing; most often it is strip stock of suitable width, thickness and edge configuration.

  • SKELP

Steel that is the entry material to a pipe mill. It resembles hot-rolled strip, but its properties allow for the severe forming and welding operations required for pipe production

  • SKIM GATE

A gating arrangement designed to prevent the passage of slag and other undesirable materials into a casting.

  • SKIMMER

A tool for removing scum, slag and dross from the surface of molten metal.

  • SKIN LAMINATION

In flat-rolled metals a surface rupture resulting from the exposure of a subsurface lamination by rolling.

  • SKIN PASS

See temper rolling.

  • SKIVING

(1) Removal of a material in thin layers or chips with a high de- gree of shear or slippage, or both, of the cutting tool. (2) A machining operation in which the cut is made with a form tool with its face so angled that the cutting edge progresses from one end of the work to the other as the tool feeds tangentially past the rotating workpiece.

  • SKULL

A layer of solidified metal or dross on the walls of a pouring vessel after the metal has been poured.

  • SLAB

A piece of metal, intermediate between ingot and plate, with the width at least twice the thickness.

  • SLAB

The most common type of semi-finished steel. Traditional slabs measure 10 inches thick and 30-85 inches wide (and average about 20 feet long), while the output of the recently developed "thin slab" casters is approximately two inches thick. Subsequent to casting, slabs are sent to the hot-strip mill to be rolled into coiled sheet and plate products

  • SLAB MILLING

See preferred term, peripheral milling.

  • SLABBING MILL

A primary mill that produces slabs.

  • SLACK QUENCHING

The incomplete hardening of steel due to quenching from the austenitizing temperature at a rate slower than the critical cooling rate for the particular steel, resulting in the formation of one or more transformation products in addition to martensite.

  • SLAG

A nonmetallic product resulting from the mutual dissolution of flux and nonmetallic impurities in smelting, refining, and certain welding operations.

  • SLAG

The impurities in a molten pool of iron. Flux such as limestone may be added to foster the congregation of undesired elements into a slag. Because slag is lighter than iron, it will float on top of the pool, where it can be skimmed

  • SLAG INCLUSION

Slag or dross entrapped in a metal.

  • SLANT FRACTURE

A type of fracture appearance, typical of plane-stress fractures, in which the plane of metal separation is inclined at an angle (usually about 45�) to the axis of applied stress.

  • SLIDE

Main reciprocating member of a mechanical press, guided in a press frame and to which the punch or upper die is fastened.

  • SLIDING FIT

A loosely defined fit similar to a slip fit.

  • SLIME

(1) A material of extremely fine particle size encountered in ore treatment. (2) A mixture of metals and some insoluble compounds that forms on the anode in electrolysis.

  • SLIP BAND

A group of parallel slip lines so closely spaced as to appear as a single line when observed under an optical microscope. See slip line.

  • SLIP DIRECTION

The crystallographic direction in which the translation of slip takes place.

  • SLIP FLASK

A tapered flask that depends on a movable strip of metal to hold the sand in position. After closing the mold, the strip is retracted and the flask can be removed and reused. Molds thus made are usually supported by a mold jacket during pouring.

  • SLIP LINE

The trace of the slip plane on the viewing surface; the trace is (usually) observable only if the surface has been polished before deformation. The usual observation on metal crystals (under the light microscope) is of a cluster of slip lines known as a slip band.

  • SLIP PLANE

The crystallographic plane in which slip occurs in a crystal.

  • SLIP-INTERFERENCE THEORY

Theory involving the resistance to deformation offered by a hard phase dispersed in a ductile matrix.

  • SLITTING

Cutting a sheet of steel into narrower strips to match customer needs. Because steel mills have limited flexibility as to the widths of the sheet that they produce, service centers normally will cut the sheet for the customer

  • SLIVER

An imperfection consisting of a very thin elongated piece of metal attached by only one end to the parent metal into whose surface it has been worked.

  • SLOPE CONTROL

Producing electronically a gradual increase or decrease in the welding current between definite limits and within a selected time interval.

  • SLOT WELD

Similar to plug weld, the difference being that the hole is elongated and may extend to the edge of a member without closing.

  • SLOTTING

Cutting a narrow aperture or groove with a reciprocating tool in a vertical shaper or with a cutter, broach or grinding wheel.

  • SLUG

(1) A short piece of metal to be placed in a die for forging or extruding. (2) A small piece of material produced by piercing a hole in sheet material.

  • SLUGGING

The unsound practice of adding a separate piece of material in a joint before or during welding, resulting in a welded joint in which the weld zone is not entirely built up by adding molten filler metal or by melting and recasting base metal, and therefore does not comply with design, drawing or specification requirements.

  • SLUSH CASTING

A hollow casting usually made of an alloy with a low but wide melting temperature range. After the desired thickness of metal has solidified in the mold, the remaining liquid is poured out.

  • SMELTING

Thermal processing wherein chemical reactions take place to produce liquid metal from a beneficiated ore.

  • SMITH FORGING

Manual forging with flat or simple-shaped dies that never completely confine the work.

  • SMUT

A reaction product sometimes left on the surface of a metal after pickling, electroplating or etching.

  • S-N DIAGRAM

A plot showing the relationship of stress, S, and the number of cycles, N, before fracture in fatigue testing.

  • SNAGGING

Offhand grinding on castings and forgings to remove surplus metal such as gate and riser pads, fins and parting lines.

  • SNAKE

(1) The product formed by twisting and bending of hot rod prior to its next rolling process. (2) Any crooked surface imperfection in a plate, resembling a snake. (3) A flexible mandrel used in the inside of a shape to prevent flattening or collapse during a bending operation.

  • SNAP FLASK

A foundry flask hinged on one corner so that it can be opened and removed from the mold for reuse before the metal is poured.

  • SNAP TEMPER

A precautionary interim stress-relieving treatment applied to high-hardenability steels immediately after quenching to prevent cracking because of delay in tempering them at the prescribed higher temperature.

  • SNOWFLAKES

See flakes.

  • SNUG FIT

A loosely defined fit implying the closest clearances that can be assembled manually for firm connection between parts.

  • SOAK CLEANING

Immersion cleaning without electrolysis.

  • SOAKING

Prolonged holding at a selected temperature to effect homogenization of structure or composition.

  • SOFT SOLDERING

See preferred term, soldering.

  • SOFT TEMPER

Same as dead soft temper.

  • SOIL

Undesirable material on a surface and yet not an integral part of the surface. Oil, grease and dirt can be soils, a decarburized skin or excess hard chromium are not soils. Loose scale is soil; hard scale may be an integral part of the surface and, hence, not soil.

  • SOLDER EMBRITTLEMENT

Reduction in mechanical properties of a metal as a result of local penetration of solder along grain boundaries.

  • SOLDER SHORT

See bridging (5).

  • SOLDERABILITY

The ease with which a surface is wetted by solder.

  • SOLDERING

A group of processes that join metals by heating them to a suitable temperature below the solidus of the base metals and applying a filler metal having a liquidus not exceeding 450 �C (840 �F). Molten filler metal is distributed between the closely fitted surfaces of the joint by capillary action.

  • SOLID CUTTERS

Cutters made of a single piece of material rather than a composite of two or more materials.

  • SOLID SHRINKAGE

See casting shrinkage.

  • SOLID SOLUTION

A single solid homogeneous crystalline phase containing two or more chemical species.

  • SOLID STATE WELDING

A group of welding processes that join metals at temperatures essentially below the melting point of the base materials, without the addition of a brazing or soldering filler metal. Pressure may or may not be applied to the joint.

  • SOLIDIFICATION

The change in state from liquid to solid on cooling through the melting temperature or melting range.

  • SOLIDIFICATION SHRINKAGE

See casting shrinkage.

  • SOLIDUS

In a constitution or equilibrium diagram, the locus of points representing the temperatures at which various compositions finish freezing on cooling or begin to melt on heating. See also liquidus

  • SOLUBLE OIL

Specially prepared oil whose water emulsion is used as a cutting or grinding fluid.

  • SOLUTE

The component of either a liquid or solid solution that is present to a lesser or minor extent, the component that is dissolved in the solvent.

  • SOLUTION HEAT TREATMENT

Heating an alloy to a suitable temperature, holding at that temperature long enough to cause one or more constituents to enter into solid solution, and then cooling rapidly enough to hold these constituents in solution.

  • SOLUTION POTENTIAL

Electrode potential where the half-cell reaction involves only the metal electrode and its ion.

  • SOLVENT

The component of either a liquid or solid solution that is present to a greater or major extent; the component that dissolves the solute.

  • SOLVUS

In a constitution or equilibrium diagram, the locus of points representing the temperatures at which the various compositions of the solid phases coexist with other solid phases, that is, the limits of solid solubility.

  • SONIC TESTING

Any inspection method that uses sound waves (in the audible frequency range, about 20 to 20 000 Hz) to induce a response from a part or test specimen. Sometimes used, but inadvisedly, as a synonym for ultrasonic testing.

  • SORBITE

(obsolete) A fine mixture of ferrite and cementite produced either by regulating the rate of cooling of steel or by tempering steel after hardening. The first type is very fine pearlite difficult to resolve under the microscope; the second type is tempered martensite.

  • SOW BLOCK

In forging, a removable block of metal set into the hammer anvil to protect the anvil from shock and wear and occasionally to hold insert dies. Also called an anvil cap or a shoe.

  • SPACE LATTICE

A regular, periodic array of points (lattice points) in space that represents the locations of atoms of the same kind in a perfect crystal. The concept may be extended, where appropriate, to crystalline compounds and other substances, in which case the lattice points often represent locations of groups of atoms of identical composition, arrangement and orientation.

  • SPACER STRIP

A metal strip or bar inserted in the root of a joint prepared for a groove weld, to serve as a backing and to maintain root opening throughout the course of the welding operation.

  • SPADE DRILL

See preferred term, flat drill.

  • SPALING

The cracking and flaking of particles out of a surface.

  • SPANGLE

The characteristic crystalline form in which a hot dipped zinc coating solidifies on steel strip.

  • SPATTER

The metal particles expelled during arc or gas welding. They do not form part of the weld.

  • SPATTER LOSS

The metal lost due to spatter.

  • SPECIAL BAR QUALITY (SBQ)

SBQ represents a wide variety of higher-quality carbon and alloy bars that are used in the forging, machining and cold-drawing industries for the production of automotive parts, hand tools, electric motor shafts and valves. SBQ generally contains more alloys than merchant quality and commodity grades of steel bars, and is produced with more precise dimensions and chemistry

  • SPECIALTY STEEL

Category of steel that includes electrical (see Silicon Electrical Steel), alloy (see Alloy Steel), stainless (see Stainless Steel), and tool (see Tool Steels) steels

  • SPECIALTY TUBE

Refers to a wide variety of high-quality custom-made tubular products requiring critical tolerances, precise dimensional control and special metallurgical properties. Specialty tubing is used in the manufacture of automotive, construction and agricultural equipment, and in industrial applications such as hydraulic cylinders, machine parts and printing rollers. Because of the range of industrial applications, the market typically follows general economic conditions

  • SPECIFIC ENERGY

In cutting or grinding, the energy expended or work done in removing a unit volume of material.

  • SPECIFIC POWER

Same as unit power.

  • SPECIMEN

A test object, often of standard dimensions or configuration, that is used for destructive or nondestructive testing. One or more specimens may be cut from each unit of a sample.

  • SPEED OF TRAVEL

In welding, the speed with which a weld is made along its longitudinal axis, usually measured in inches per minute or spots per minute.

  • SPEISS

Metallic arsenides and antimonides that result from smelting metal ores such as those of cobalt.

  • SPELTER

Crude zinc obtained in smelting zinc ores.

  • SPELTER SOLDER

A brazing filler metal of approximately equal parts of copper and zinc.

  • SPHEROIDIZING

Heating and cooling to produce a spheroidal or globular form of carbide in steel. Spheroidizing methods frequently used are: 1 Prolonged holding at a temperature just below Ae1. 2 Heating and cooling alternately between temperatures that are just above and just below Ael. 3 Heating to a temperature above Ae1 or Ae3 and then cooling very slowly in the furnace or holding at a temperature just below Ae1. 4 Cooling at a suitable rate from the minimum temperature at which all carbide is dissolved, to prevent the reformation of a carbide network, and then reheating in accordance with method 1 or 2 above. (Applicable to hypereutectoid steel containing a carbide network.)

  • SPHERULITIC GRAPHITE CAST IRON

Same as ductile cast iron.

  • SPIDER DIE

Same as porthole die.

  • SPIEGELEISEN (SPIEGEL)

A pig iron containing 15 to 30percent Mn and 4.5 to 6.5percent C.

  • SPINDLE

(1) Shaft of a machine tool on which a cutter or grinding wheel may be mounted. (2) Metal shaft to which a mounted wheel is cemented.

  • SPINNING

Forming a seamless hollow metal part by forcing a rotating blank to conform to a shaped mandrel that rotates concentrically with the blank. In the usual application, a flat-rolled metal blank is forced against the mandrel by a blunt, rounded tool; however, other stock (notably welded or seamless tubing) can be formed, and sometimes the working end of the tool is a roller.

  • SPINODAL STRUCTURE

A fine homogeneous mixture of two phases that form by the growth of composition waves in a solid solution during suitable heat treatment. The phases of a spinodal structure differ in composition from each other and from the parent phase but have the same crystal structure as the parent phase.

  • SPLINE

Any of a series of longitudinal, straight projections on a shaft that fit into slots on a mating part to transfer rotation to or from the shaft.

  • SPLIT DIE

Same as segment die.

  • SPONGE

A form of metal characterized by a porous condition that is the result of the decomposition or reduction of a compound without fusion. The term is applied to forms of iron, titanium, zirconium, uranium, plutonium and the platinum-group metals.

  • SPONGE IRON

Either porous or powdered iron produced directly without fusion, as by heating high-grade ore with charcoal, or an oxide with a reducing gas.

  • SPOT DRILLING

Making an initial indentation in a work surface, with a drill, to serve as a centering guide in a subsequent machining operation.

  • SPOT FACING

Machining a flat seat for a bolt head, nut or other similar element at the end of and at right angles to the axis of a previously made hole.

  • SPOT MARKET

Sales for delivery in less than three months

  • SPOT WELDING

Welding of lapped parts in which fusion is confined to a relatively small circular area. It is generally resistance welding, but may also be gas tungsten-arc, gas metal-arc, or submerged-arc welding.

  • SPOTTING

Fitting one part of a die to another by applying an oil color to the surface of the finished part and bringing this against the surface of the intended mating part, the high spots being marked by the transferred color.

  • SPOTTING OUT

Delayed, uneven staining of metal by entrapment of chemicals during the finishing operation.

  • SPRAY METALLIZING

See metallizing.

  • SPRAY QUENCHING

Quenching in a spray of liquid.

  • SPRAY TRANSFER

In consumable-electrode arc welding, a type of metal transfer in which the molten filler metal is propelled across the arc as fine droplets. Compare with globular transfer, short circuiting transfer.

  • SPRING TEMPER

A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about two-thirds of the way from full hard to extra spring temper.

  • SPRINGBACK

(1) The elastic recovery of metal after cold forming. (2) The degree to which metal tends to return to its original shape or contour after undergoing a forming operation. (3) In flash, upset or pressure welding, the deflection in the welding machine

  • SPRUE

(1) The mold channel that connects the pouring basin with the runner or, in the absence of a pouring basin, directly into which molten metal is poured. Sometimes referred to as downsprue or downgate. (2) Sometimes used to mean all gates, risers, runners and similar scrap that are removed from castings after shakeout.

  • SQUARE DRILLING

Making square holes by means of a specially constructed drill made to rotate and also to oscillate so as to follow accurately the periphery of a square guide bushing or template.

  • SQUARE GROOVE WELD

A groove weld in which the abutting surfaces are square.

  • SQUARING SHEAR

A machine tool, used for cuttiny sheet metal or plate, consisting essentially of a fixed cutting knife (usually mounted on the rear of the bed) and another cutting knife mounted on the front of a reciprocally moving crosshead, which is guided vertically in side housings. Corner angles are usually 90�.

  • SQUEEZE TIME

In resistance welding the time between the initial applications of pressure and current.

  • STABILIZING TREATMENT

(1) Before finishing to final dimensions, repeatedly heating a ferrous or nonferrous part to or slightly above its normal operating temperature and then cooling to room temperature to ensure dimensional stability in service. (2) Transforming retained austenite in quenched hardenable steels, usually by cold treatment. (3) Heating a solution-treated stabilized grade of austenitic stainless steel to 870 to 900 �C (1600 to 1650 �F) to precipitate all carbon as TiC, NbC, or TaC so that sensitization is avoided on subsequent exposure to elevated temperature.

  • STACK CUTTING

Oxyfuel gas cutting of stacked metal plates arranged so that all are severed by a single cut.

  • STACK MOLDING

A molding method that makes use of both faces of a mold section, one face acting as the drag and the other as the cope. Sections, when assembled to other similar sections, form several tiers of mold cavities, all castings being poured together through a common sprue.

  • STACK WELDING

Resistance spot welding of stacked plates, all being joined simultaneously.

  • STAGGERED-INTERMITTENT FILLET WELDING

Making a line of intermittent fillet welds on each side of a joint so that the increments on one side are not opposite those on the other. Contrast with chain-intermittent fillet welding.

  • STAGGERED-TOOTH CUTTERS

Milling cutters with alternate flutes of oppositely directed helixes.

  • STAINLESS STEEL

Any of several steels containing 12 to 30percent chromium as the principle alloying element, they usually exhibit passivity in aqueous environments.

  • STAINLESS STEEL

The term for grades of steel that contain more than 10percent chromium, with or without other alloying elements. Stainless steel resists corrosion, maintains its strength at high temperatures, and is easily maintained. For these reasons, it is used widely in items such as automotive and food processing products, as well as medical and health equipment. The most common grades of stainless steel are

  • STAKING

Fastening two parts together permanently by recessing one part within the other and then causing plastic flow at the joint.

  • STALAGMOMETER

An apparatus for determining surface tension. The mass of a drop of liquid is measured by weighing a known number of drops or by counting the number of drops obtained from a given volume of the liquid.

  • STAMPING

A general term covering almost all press operations. It includes blanking, shearing, hot or cold forming, drawing, bending, coining.

  • STAND

A piece of rolling mill equipment containing one set of working rolls. In the usual sense, any pass of a continuous, looping or cross-country hot rolling mill.

  • STANDARD ELECTRODE POTENTIAL

The reversible electrode potential where all reactants and products are at unit activity.

  • STANDARD GOLD

A legally adopted alloy for coinage of gold. In the United States the alloy contains 10percent Cu.

  • STARDUSTING

An extremely fine form of roughness on the surface of a metal deposit.

  • STARTING SHEET

A thin sheet of metal used as the cathode in electrolytic refining.

  • STATE OF STRAIN

A complete description of the deformation within a homogeneously deformed volume or at a point. The description requires, in general, the knowledge of six independent components of strain.

  • STATE OF STRESS

A complete description of the stresses within a homogeneously stressed volume or at a point. The description requires, in general, the knowledge of six independent components of stress.

  • STATIC FATIGUE

A term sometimes used to identify a form of hydrogen embrittlement in which a metal appears to fracture spontaneously under a steady stress less than the yield stress. There almost always is a delay between the application of stress (or exposure of the stressed metal to hydrogen) and the onset of cracking. More properly referred to as hydrogen-induced delayed cracking.

  • STATISTICAL PROCESS CONTROL (SPC)

A technique used to predict when a steelmaking function's quality may deteriorate, By tightly monitoring the product's variance from specifications, the operator ca' determine when to apply preventative maintenance to a machine before any low quality (secondary) steel is produced

  • STEADITE

A hard structural constituent of cast iron that consists of a binary eutectic of ferrite (containing some phosphorus in solution) and iron phosphide (Fe3P). The composition of the eutectic is 10.2percent P, 89.8percent Fe, and the melting temperature is 1050 �C (1920 �F).

  • STEAD'S BRITTLENESS

A condition of brittleness that causes transcrystalline fracture in the coarse grain structure that results from prolonged annealing of thin sheets of low-carbon steel previously rolled at a temperature below about 705 �C (1300 �F). The fracture usually occurs at about 45� to the direction of rolling.

  • STEADYREST

In cutting or grinding, a stationary support for a long workpiece.

  • STECKEL MILL

A cold reducing mill having two working rolls and two backup rolls, none of which is driven. The strip is drawn through the mill by a power reel in one direction as far as the strip will allow and then reversed by a second power reel and so on until the desired thickness is attained.

  • STECKEL MILL

A reversing steel sheet reduction mill with heated coil boxes at each end. Steel sheet or plate is sent through the rolls of the reversing mill and coiled at the end of the mill, reheated in the coil box, and sent back through the Steckel stands and recoil By reheating the steel prior to each pass, the rolls can squeeze the steel thinner per pass and impart a better surface finish

  • STEEL

An iron-base alloy, malleable in some temperature ranges as initially cast, containing manganese, usually carbon, and often other alloying elements. In carbon steel and low-alloy steel, the maximum carbon is about 2.0percent; in high-alloy steel, about 2.5percent. The dividing line between low-alloy and high-alloy steels is generally regarded as being at about 5percent metallic alloying elements. Steel is to be differentiated from two general classes of "irons": the cast irons, on the high-carbon side, and the relatively pure irons such as ingot iron, carbonyl iron, and electrolytic iron, on the low-carbon side. In some steels containing extremely low carbon, the manganese content is the principle differentiating factor, steel usually containing at least 0.25percent; ingot iron, considerably less.

  • STEEL INTENSITY

The amount of steel used per unit of gross domestic product. Intensity reflects the secular demand for steel, as opposed to cyclical demand. The amount of steel use in vehicles and the popularity of alternative materials affect the intensity, or how much steel is needed per unit produced. The state of the economy, however, determines the number of units

  • STEEL LNTENSIVE PRODUCTS

Consumer products such as automobiles and appliances that, because so much of their weight is from steel, exhibit a high demand correlation with steel

  • STEEL SERVICE CENTER INVENTORIES

End-of-period material stocks reported by the Steel Service Center Institute (SSCI)

  • STEEL STRAPPING

Banding and packaging material that is used to close and reinforce shipping units, such as bales, boxes, cartons, coils, crates, and skids

  • STEP AGING

Aging at two or more temperatures, by steps, without cooling to room temperature after each step. See aging, and compare with interrupted aging and progressive aging.

  • STEPPED EXTRUSION

A product with one or more abrupt cross-sectional changes usually obtained by interrupting the extrusion operation and exchanging dies.

  • STEREORADIOGRAPHY

A technique for producing paired radiographs that may be viewed with a stereoscope to exhibit a shadowgraph in three dimensions with various sections in perspective and spatial relation.

  • STERLING SILVER

A silver alloy containing at least 92.5percent Ag, the remainder being unspecified but usually copper.

  • STICK ELECTRODE

A shop term for covered electrode.

  • STICKER BREAK

Arc-shaped coil break usually located near the center of sheet or strip.

  • STIFFNESS

The ability of a metal or shape to resist elastic deflection. For identical shapes, the stiffness is proportional to the modulus of elasticity. For a given material, the stiffness increases with increasing moment of inertia, which is computed from cross-sectional dimensions.

  • STOCK

A general term for solid starting material that is formed, forged or machined to make parts.

  • STOKING

(obsolete) Presintering, or sintering, in such a way that powder metallurgy compacts are advanced through the furnace at a fixed rate by manual or mechanical means; also called continuous sintering.

  • STOP-OFF

See resist.

  • STOPPER ROD

A device in a bottom-pour ladle for controlling the flow of metal through the nozzle into a mold. The stopper rod consists of a steel rod, protective refractory sleeves and a graphite stopper head.

  • STOPPING OFF

(1) Applying a resist. (2) Depositing a metal (copper, for example) in localized areas to prevent carburization, decarburization or nitriding in those areas. (3) Filling in a portion of a mold cavity to keep out molten metal.

  • STORED-ENERGY WELDING

Welding with electrical energy accumulated electrostatically, electromagnetically or electrochemically at a relatively low rate and made available at the higher rate required in welding.

  • STRADDLE MILLING

Face milling a workpiece on both sides at once using two cutters spaced as required.

  • STRAIGHT POLARITY

Direct-current arc welding circuit arrangement in which the electrode is connected to the negative terminal. Contrast with reverse polarity.

  • STRAIN

A measure of the relative change in the size or shape of a body. Linear strain is the change per unit length of a linear dimension. True strain (or natural strain) is the natural logarithm of the ratio of the length at the moment of observation to the original gage length. Conventional strain is the linear strain over the original gage length. Shearing strain (or shear strain) is the change in angle (expressed in radians) between two lines originally at right angles. When the term "strain" is used alone it usually refers to the linear strain in the direction of applied stress. See also state of strain.

  • STRAIN AGING

Aging induced by cold working. See aging.

  • STRAIN ENERGY

(1) The work done in deforming a body. (2) The work done in deforming a body within the elastic limit of the material. It is more properly termed elastic strain energy and can be recovered as work rather than heat.

  • STRAIN RATE

The time rate of straining for the usual tensile test. Strain as measured directly on the specimen; gage length is used for determining strain rate. Because strain is dimensionless, the units of strain rate are reciprocal time.

  • STRAIN RODS

(1) Rods sometimes used on gapframe presses to lessen the frame deflection. (2) Rods used to measure elastic strains, and thus stresses, in frames of presses.

  • STRAIN STATE

See state of strain.

  • STRAIN-AGE EMBRITTLEMENT

A loss in ductility accompanied by an increase in hardness and strength that occurs with low-carbon steel (especially rimmed or capped steel) is aged following plastic deformation. The degree of embrittlement is a function of aging time and temperature, occurring in a matter of minutes at about 200 �C (400 �F) but requiring a few hours to a year at room temperature.

  • STRAIN-HARDENING EXPONENT

A measure of rate of strain hardening. The constant n in the expression: ( = (0 (n where a is true stress, (0 is true stress at unit strain, and ( is true strain.

  • STRAIN-RATE SENSITIVITY

Qualitatively, the increase in stress (s) needed to cause a certain increase in plastic strain rate (e) at a given level of plastic strain (e) and a given temperature (T). Strain-rate sensitivity = m =Dlogs/Dloge

  • STRAND CASTING

A generic term describing continuous casting of one or more elongated shapes such as billets, blooms or slabs; if two or more strands are cast simultaneously, they are often of identical cross section.

  • STRAY CURRENT

Current flowing in electrodeposition by way of an unplanned and undesired bipolar electrode that may be the tank itself or a poorly connected electrode.

  • STRENGTH

Properties related to the ability of steel to oppose applied forces. Forms of strength include withstanding imposed loads without a permanent change in shape or structure and resistance to stretching

  • STRESS

Force per unit area, often thought of as force acting through a small area within a plane. It can be divided into components, normal and parallel to the plane, called normal stress and shear stress, respectively. True stress denotes the stress where force and area are measured at the same time. Conventional stress, as applied to tension and compression tests, is force divided by the original area. Nominal stress is the stress computed by simple elasticity formulas, ignoring stress raisers and disregarding plastic flow; in a notch bend test, for example, it is bending moment divided by minimum section modulus. See also state of stress.

  • STRESS AMPLITUDE

One-half the algebraic difference between the maximum and minimum stress in one cycle of a repetitively varying stress.

  • STRESS CORROSION CRACKING (SCC)

Slow growth of cracks in stainless steel caused by the combined effect of mechanical stress and exposure to a corrosive environment

  • STRESS RAISERS

Changes in contour or discontinuities in structure that cause local increases in stress.

  • STRESS RANGE

The algebraic difference between the maximum and minimum stress in one cycle of a repetitively varying stress.

  • STRESS RATIO

In fatigue, the ratio of the minimum stress to the maximum stress in one cycle, considering tensile stresses as positive, compressive stresses as negative.

  • STRESS RELIEVING

Heating to a suitable temperature, holding long enough to reduce residual stresses and then cooling slowly enough to minimize the development of new residual stresses.

  • STRESS STATE

See state of stress.

  • STRESS-CONCENTRATION FACTOR

(Kt). A multiplying factor for applied stress that allows for the presence of a structural discontinuity such as a notch or hole; Kt equals the ratio of the greatest stress in the region of the discontinuity to the nominal stress for the entire section.

  • STRESS-CORROSION CRACKING

Failure by cracking under combined action of corrosion and stress, either external (applied) stress or internal (residual) stress. Cracking may be either intergranular or transgranular, depending on metal and corrosive medium.

  • STRESS-INTENSITY FACTOR

A scaling factor, usually denoted by the symbol K, used in linear-elastic fracture mechanics to describe the intensification of applied stress at the tip of a crack of known size and shape. At the onset of rapid crack propagation in any structure containing a crack, the factor is called the critical stress-intensity factor, or the fracture toughness. Various subscripts are used to denote different loading conditions or fracture toughnesses. The most common subscripts, and their meanings, are: KC. Plane-stress fracture toughness. The value of stress intensity at which crack propagation becomes rapid in sections thinner than those in which plane strain conditions prevail. KI. Stress-intensity factor for a loading condition that displaces the crack faces in a direction normal to the crack plane (also known as the opening mode of deformation). KIc. Plane-strain fracture toughness. The minimum value of Kc for any given material and condition, which is attained when rapid crack propagation in the opening mode is governed by plane-strain conditions. KId. Dynamic fracture toughness. The fracture toughness determined under dynamic loading conditions; it is used as an aproximation of Klc for very tough materials. KIscc. Threshold stress intensity for stress-corrosion cracking. A value of stress intensity characteristic of a specific combination of material, material condition and corrosive environment above which stress-corrosion crack propagation occurs and below which the material is immune from stress-corrosion cracking.

  • STRESS-RUPTURE TEST

A method of evaluating elevated-temperature durability in which a tension-test specimen is stressed under constant load until it breaks. Data recorded commonly include: initial stress, time to rupture, initial extension, creep extension, reduction of area at fracture. Also known as creep-rupture test.

  • STRETCH FORMER

(1) A machine used to perform stretch forming operations. (2) A device adaptable to a conventional press for accomplishing stretch forming.

  • STRETCH FORMING

Shaping of a sheet or part, usually of uniform cross section, by first applying suitable tension or stretch and then wrapping it around a die of the desired shape.

  • STRETCH WIPE FORMING

Same as wiper forming.

  • STRETCHER LEVELING

Leveling a piece of metal (that is, removing warp and distortion) by gripping it at both ends and subjecting it to a stress higher than its yield strength. Sometimes called patent leveling.

  • STRETCHER STRAIGHTENING

Straightening rod, tubing or shapes by gripping the stock at both ends and applying tension. The products are elongated a difinite amount to remove warpage.

  • STRETCHER STRAINS

Elongated markings that appear on the surface of some materials when deformed just past the yield point. These markings lie approximately parallel to the direction of maximum shear stress and are the result of localized yielding. See also L�ders lines.

  • STRIATION

A fatigue fracture feature, often observed in electron micrographs, that indicates the position of the crack front after each succeeding cycle of stress. The distance between striations indicates the advance of the crack front across that crystal during one stress cycle, and a line normal to the striations indicates the direction of local crack propagation.

  • STRIKE

(1) A thin electrodeposited film of metal to be followed by other plated coatings. (2) A plating solution of high covering power and low efficiency designed to electroplate a thin adherent film of metal.

  • STRIKING

Electrodepositing, under special conditions, a very thin film of metal that will facilitate further plating with another metal or with the same metal under different conditions.

  • STRIKING SURFACE

Those areas on the faces of a set of dies that are designed to meet when the upper and lower dies are brought together. Striking surface helps protect impressions from impact shock and aids in maintaining longer die life. Also called beating area.

  • STRINGER

In wrought materials, an elongated configuration of microconstituents or foreign material aligned in the direction of working. Commonly, the term is associated with elongated oxide or sulfide inclusions in steel.

  • STRINGER BEAD

A continuous weld bead made without appreciable transverse oscillation. Contrast with weave bead.

  • STRIP

A flat-rolled metal product of some maximum thickness and width arbitrarily dependent on the type of metal. It is narrower than sheet.

  • STRIP

Thin, flat steel that resembles hot-rolled sheet, but it is normally narrower (up to 12 inches wide) and produced to more closely controlled thicknesses. Strip also may be cut from steel sheet by a slitting machine (see Sheet Steel)

  • STRIPPER PUNCH

A punch that serves as top or bottom of the die cavity and later moves farther into the die to eject the part or compact.

  • STRIPPING

Removing a coating from a metal surface.

  • STRUCTURAL SHAPE

Piece of metal of any of several designs accepted as standard by the structural branch of the iron and steel industries.

  • STRUCTURALS

Steel product group that includes I-beams, H-beams, wide-flange beams, and sheet piling. These products are used in the construction of multi-story buildings, industrial buildings, bridge trusses, vertical highway supports, and riverbank reinforcement

  • STUD ARC WELDING

An arc welding process that produces coalescence of metals by heating them with an arc between a metal stud, or similar part and another part. When the surfaces to be joined are properly heated, they are brought together under pressure. Partial shielding may be obtained by the use of a ceramic ferrule surrounding the stud. Shielding gas or flux may or may not be used.

  • SUBBOUNDARY STRUCTURE

A network of low-angle boundaries (usually less than one degree) within the main crystals of a metallographic structure.

  • SUBCRITICAL ANNEALING

A process anneal performed on ferrous alloys at a temperature below Acl.

  • SUBGRAIN

A portion of a crystal or grain, with an orientation slightly different from the orientation of neighboring portions of the same crystal. Generally, neighboring subgrains are separated by low-angle boundaries such as tilt boundaries

  • SUBMERGED-ARC WELDING

Arc welding in which the arc, between a bare metal electrode and the work, is shielded by a blanket of granular, fusible material overlying the joint. Pressure is not applied to the joint, and filler metal is obtained from the consumable electrode (and sometimes from a supplementary welding rod).

  • SUBSIEVE ANALYSIS

Size distribution of particles all of which will pass through a 44-(m (No. 325) standard sieve, as determined by specified methods.

  • SUBSTITUTIONAL SOLID SOLUTION

A solid solution in which the solute atoms are located at some of the lattice points of the solvent, the distribution being random. Contrast with interstitial solid solution.

  • SUBSTRATE

Layer of metal underlying a coating, regardless of whether the layer is basis metal.

  • SUBSTRATE

Raw material used as an input for steel processing: For example, hot-rolled steel is the substrate for cold-rolling operations

  • SUBSTRUCTURE

Same as subboundary structure.

  • SUBSURFACE CORROSION

Formation of isolated particles of corrosion products beneath a metal surface. This results from the preferential reaction of certain alloy constituents by inward diffusion of oxygen, nitrogen or sulfur.

  • SULFUR DOME

An inverted container holding a high concentration of sulfur dioxide gas, used in die casting to cover a pot of molten magnesium to prevent burning.

  • SULFUR PRINT

A macrographic method of examining for distribution of sulfide inclusions by placing a sheet of wet acidified photographic paper in contact with the polished steel surface to be examined.

  • SUPERALLOY

See heat-resisting alloy.

  • SUPERCONDUCTIVITY

The abrupt and large increase in electrical conductivity exhibited by some metals as the temperature approaches absolute zero.

  • SUPERCOOLING

Cooling below the temperature at which an equilibrium phase transformation can take place without actually obtaining the transformation.

  • SUPERFICIAL ROCKWELL HARDNESS TEST

Form of Rockwell hardness test using relatively light loads that produce minimum penetration by the indenter. Used for determining surface hardness or hardness of thin sections or small parts, or where a large hardness impression might be harmful.

  • SUPERFINES

The portion of a metal powder that is composed of particles smaller than a specified size, usually less than 10 �m.

  • SUPERFINISHING

A form of honing in which the abrasive stones are spring supported.

  • SUPERHEATING

(1) Heating above the temperature at which an equilibrium phase transformation should occur without actually obtaining the transformation. (2) Heating molten metal above the normal casting temperature so as to obtain more complete refining or greater fluidity.

  • SUPERLATTICE

A lattice arrangement in which solute and solvent atoms of a solid solution occupy different preferred sites in the array. Contrast with disordering.

  • SUPERPLASTICITY

The ability of certain metals to undergo unusually large amounts of plastic deformation before local necking occurs.

  • SUPERSONIC

Pertains to phenomena in which the speed is higher than that of sound. Not synonymous with ultrasonic; see ultrasonic frequency.

  • SUPPORT PINS

Rods or pins of accurate length used to support the overhang of irregularly shaped punches.

  • SUPPORT PLATE

A plate that supports the draw ring or draw plate. It also serves as a spacer.

  • SURFACE FINISH

(1) Condition of a surface as a result of a final treatment. (2) Measured surface profile characteristics, the preferred term being roughness.

  • SURFACE GRINDING

Producing a plane surface by grinding.

  • SURFACE HARDENING

A generic term covering several processes applicable to a suitable ferrous alloy that produces, by quench hardening only, a surface layer that is harder or more wear resistant than the core. There is no significant alteration of the chemical composition of the surface layer. The processes commonly used are induction hardening, flame hardening and shell hardening. Use of the applicable specific process name is preferred.

  • SURFACE ROUGHNESS

See roughness.

  • SURFACE TENSION

Interfacial tension between two phases, one of which is a gas.

  • SURFACING

The deposition of filler metal on a metal surface by welding, spraying or braze welding, to obtain certain desired properties or dimensions. See also hard facing.

  • SURFACING WELD

A type of weld composed of one or more stringer or weave beads deposited on an unbroken surface to obtain desired properties or dimensions.

  • SUSPENSION AGREEMENT

A resolution of an unfair trade dispute that can suspend further proceedings in an unfair trade suit. The U.S. government, in consultation with the domestic industry, can enter into such an agreement with the foreign industry

  • SWAGING

Tapering bar, rod, wire or tubing by forging, hammering or squeezing; reducing a section by progressively tapering lengthwise until the entire section attains the smaller dimension of the taper.

  • SWARF

Intimate mixture of grinding chips and fine particles of abrasive and bond resulting from a grinding operation.

  • SWEAT

Exudation of a low-melting phase during solidification. Also known as sweatback. For tin bronzes, it is called tin sweat.

  • SWEATING

A soldering technique in which two or more parts are precoated (tinned), then reheated and joined without adding more solder. Also called sweat soldering.

  • SWEATING OUT

Bringing small globules of one of the low-melting constituents of an alloy to the surface during heat treatment, as lead out of bronze

  • SWEEP

A form or template used for shaping sand molds or cores by hand.

  • SWEEPS

Floor and table sweepings containing precious metal particles.

  • SWEET ROAST

Same as dead roast.

  • SWING FORGING MACHINE

Equipment for continuously hot reducing ingots, blooms, or billets to square flats, rounds, or rectangles by the crankdriven oscillating action of paired dies.

  • SWING-FRAME GRINDER

A grinding machine suspended by a chain at the center point so that it may be turned and swung in any direction for the grinding of billets, large castings, or other heavy work. Principal use is removing surface imperfections and roughness.

  • SYNCHRONOUS TIMING

In spot, seam or projection welding, a method of regulating the welding transformer primary current so that all the following conditions will prevail: (a) The first half-cycle is initiated at the proper time in relation to the voltage to ensure a balanced current wave; (b) each succeeding half-cycle is essentially identical to the first; and (c) the last half-cycle is of opposite polarity to the first.

  • SYNTECTIC

An isothermal reversible reaction in which a solid phase, on absorption of heat, is converted to two conjugate liquid phases.

  • SYNTHETIC COLD ROLLED SHEET

A hot rolled pickled sheet given a sufficient final temper pass to impart a surface approximating that of cold rolled steel.

  • TACK WELDS

Small scattered welds made to hold parts of a weldment in proper alignment while the final welds are being made.

  • TACKING

Making tack welds.

  • TACONITE

A siliceous iron formation from which certain iron ores of the Lake Superior region are derived; consists chiefly of fine-grain silica mixed with magnetite and hematite.

  • TACONITE

WHAT. Natural mineral containing less than 30percent iron. It is the primary ore used in blast furnaces. WHY. Domestic supplies of iron-rich ores (greater than 50percent iron) were largely depleted in the 1940s, so integrated steel companies now process the lower-grade taconite to make it useful

  • TAILINGS

The discarded portion of a crushed ore, separated during concentration.

  • TAILORED BLANKS

A section of sheet or strip that is cut-to-length and trimmed to match specifications for the manufacturers stamping design for a particular part. Because excess steel is cut away (to save shipping costs), all that remains for the stamper is to impart the three-dimensional shape with a die press (see Blanking)

  • TANDEM DIE

Same as follow die.

  • TANDEM MILL

A rolling mill consisting of two or more stands arranged so that the metal being processed travels in a straight line from stand to stand. In continuous rolling, the various stands are synchronized so that the strip may be rolled in all stands simultaneously. Contrast with single-stand mill.

  • TANDEM MILL

A type of cold-rolling mill, the tandem mill imparts greater strength, a uniform and smoother surface, and reduced thickness to the steel sheet. Unlike the original single-stand mills, a tandem mill rolls steel through a series of rolls (generally three to five in a row) to achieve a desired thickness and surface quality

  • TANDEM WELDING

Arc welding in which two or more electrodes are in a plane parallel to the line of travel.

  • TANGENT BENDING

Forming one or more identical bends having parallel axes by wiping sheet metal around one or more radius dies in a single operation. The sheet, which may have side flanges, is clamped against the radius die, then made to conform to the radius die by pressure from a rocker-plate die that moves along the periphery of the radius die.

  • TANGENT MODULUS

See modulus of elasticity.

  • TANK VOLTAGE

The total voltage between the anode and cathode of a plating bath or electrolytic cell during electrolysis. It is equal to the sum of: (a) the equilibrium reaction potential, (b) the IR drop, and (c) the electrode potentials.

  • TAP

A cylindrical or conical threadcutting tool with one or more cutting elements having threads of a desired form on the periphery. By a combination of rotary and axial motions, the leading end cuts an internal thread, the tool deriving its principal support from the thread being produced.

  • TAP DENSITY

The apparent density of a metal powder, obtained when the volume receptacle is tapped or vibrated during loading under specified conditions.

  • TAPPING

(1) Opening the outlet of a melting furnace to remove molten metal. (2) Removing molten metal from a furnace. (3) Cutting internal threads with a tap.

  • TARNISH

Surface discoloration of a metal caused by formation of a thin film of corrosion product.

  • TAYLOR PROCESS

A process for making extremely fine wire by inserting a piece of larger diameter wire into a glass tube and stretching the two together at high temperature.

  • TECHNICAL COHESIVE STRENGTH

Fracture stress in a notch tensile test. Often used instead of merely "cohesive strength" to avoid confusion among the several definitions of cohesive strength.

  • TEE JOINT

A joint in which the members are oriented in the form of a T.

  • TEEMING

Pouring molten metal from a ladle into ingot molds. The term applies particularly to the specific operation of pouring either iron or steel into ingot molds.

  • TEEMING

Pouring; ingot molds are filled (teemed) by iron-bearing ladles

  • TEMPER

(1) In heat treatment, reheating hardened steel or hardened cast iron to some temperature below the eutectoid temperature for the purpose of decreasing hardness and increasing toughness. The process also is sometimes applied to normalized steel. (2) In tool steels, temper is sometimes used, but inadvisedly, to denote the carbon content. (3) In nonferrous alloys and in some ferrous alloys (steels that cannot be hardened by heat treatment), the hardness and strength produced by mechanical or thermal treatment, or both, and characterized by a certain structure, mechanical properties, or reduction in area during cold working. (4) To moisten sand for casting molds with water.

  • TEMPER BRITTLENESS

Brittleness that results when certain steels are held within, or are cooled slowly through, a certain range of temperature below the transformation range. The brittleness is manifested as an upward shift in ductile-to-brittle transition temperature, but only rarely produces a low value of reduction of area in a smooth-bar tension test of the embrittled material.

  • TEMPER CARBON

Same as annealing carbon.

  • TEMPER COLOR

A thin, tightly adhering oxide skin (only a few molecules thick) that forms when steel is tempered at a low temperature, or for a short time, in air or a mildly oxidizing atmosphere. The color, which ranges from straw to blue depending on the thickness of the oxide skin, varies with both tempering time and temperature.

  • TEMPER MILL

A type of cold-rolling mill, usually with only one or two stands, that finishes cold rolled, annealed sheet steel by improving the finish or texture to develop the required final mechanical properties. By changing the rolls of the temper mill, steel can be shipped with a shiny, dull, or grooved surface

  • TEMPER ROLLING

Light cold rolling of sheet steel. This operation is performed to improve flatness, minimize the tendency to stretcher strain and flute, and obtain the desired texture and mechanical properties.

  • TEMPER TIME

In resistance welding, that part of the postweld interval during which the current is suitable for tempering or heat treatment.

  • TENSILE STRENGTH

In tensile testing, the ratio of maximum load to original cross-sectional area. Also called ultimate strength. Compare with yield strength.

  • TERMINAL PHASE

A solid solution having a restricted range of compositions, one end of the range being a pure component of an alloy system.

  • TERNARY ALLOY

An alloy that contains three principal elements.

  • TERNE

An alloy of lead containing 3 to 15percent tin, used as a hot dip coating for steel sheet or plate. Terne coatings which are smooth and dull in appearance, give the steel better corrosion resistance and enhance its ability to be formed, soldered or painted.

  • TERNE

Sheet steel coated with a mixture of lead and tin. Terne principally is used in the manufacture of gasoline tanks, although it also can be found in chemical containers, oil filters, and television chassis

  • TERTIARY CREEP

See creep.

  • TEXTURE

In a polycrystalline aggregate the state of distribution of crystal orientations. In the usual sense, it is synonymous with preferred orientation.

  • THERMAL ANALYSIS

A method for determining transformations in a metal by noting the temperatures at which thermal arrests occur. These arrests are manifested by changes in slope of the plotted or mechanically traced heating and cooling curves. When such data are secured under nearly equilibrium conditions of heating and cooling, the method is commonly used for determining certain critical temperatures required for the construction of equilibrium diagrams.

  • THERMAL ELECTROMOTIVE FORCE

The electromotive force generated in a circuit containing two dissimilar metals when one junction is at a temperature different from the other. See also thermocouple.

  • THERMAL FATIGUE

Fracture resulting from the presence of temperature gradients that vary with time in such a manner as to produce cyclic stresses in a structure.

  • THERMAL SHOCK

The development of a steep temperature gradient and accompanying high stresses within a structure.

  • THERMAL SPRAYING

A group of welding or allied processes in which finely divided metallic or nonmetallic materials are deposited in a molten or semimolten condition to form a coating. The coating material may be in the form of powder, ceramic rod, wire or molten materials. See also flame spraying, plasma spraying.

  • THERMAL STRESSES

Stresses in metal resulting from nonuniform temperature distribution.

  • THERMIT REACTIONS

Strongly exothermic self-propagating reactions such as that where finely divided aluminum reacts with a metal oxide. A mixture of aluminum and iron oxide produces sufficient heat to weld steel, the filler metal being produced in the reaction.

  • THERMIT WELDING

Welding with heat produced by the reaction of aluminum with a metal oxide. Filler metal if used, is obtained from the reduction of an appropriate oxide.

  • THERMOCOUPLE

A device for measuring temperatures, consisting of lengths of two dissimilar metals or alloys that are electrically joined at one end and connected to a voltage-measuring instrument at the other end. When one junction is hotter than the other, a thermal electromotive force is produced that is roughly proportional to the difference in temperature between the hot and cold junctions.

  • THERMOMECHANICAL WORKING

A general term covering a variety of processes combining controlled thermal and deformation treatments to obtain synergistic effects such as improvement in strength without loss of toughness.

  • THIEF

In electroplating, same as robber.

  • THOMAS CONVERTER

A Bessemer converter having a basic bottom and lining, usually dolomite, and employing a basic slag.

  • THREE-POINT BENDING

Bending a piece of metal, or a structural member, in which the object is placed across two supports and force is applied between and in opposition to them. See V-bend die.

  • THREE-QUARTERS HARD

A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about midway between those of half hard and full hard tempers.

  • THROAT DEPTH

On a resistance-welding machine, the distance from the centerline of the electrodes or platens to the nearest point of interference for flat work.

  • THROAT OF A FILLET WELD

(theoretical) The distance from the beginning of the root of the joint perpendicular to the hypotenuse of the largest right triangle that can be inscribed within the fillet-weld cross section. (actual) The shortest distance from the root of a fillet to its face. (effective) The minimum distance from the root of the weld to its face, minus any reinforcement. See sketches accompanying concave fillet weld, convex fillet weld.

  • THROUGH WELD

A nonpreferred term sometimes used to indicate a weld of substantial length made by melting through one member of a lap or tee joint and into the other member.

  • THROWING POWER

The ability of a plating solution to produce a uniform metal distribution on an irregularly shaped cathode. Compare with covering power.

  • TIG WELDING

Tungsten inert-gas welding; see preferred term, gas tungsten-arc welding.

  • TIGER STRIPES

Continuous bright lines on sheet or strip in the rolling direction.

  • TIGHT FIT

A loosely defined fit of slight negative allowance requiring a light press or driving force to assemble.

  • TILT BOUNDARY

A subgrain boundary consisting of an array of edge dislocations.

  • TILT MOLD

A casting mold, usually a book mold, that rotates from a horizontal to a vertical position during pouring, which reduces agitation and thus the formation and entrapment of oxides.

  • TILT MOLD INGOT

An ingot made in a tilt mold.

  • TIME QUENCHING

Interrupted quenching in which the time in the quenching medium is controlled.

  • TIN MILL

Continuous tin-plating facility to produce tin mill steel sheet to be used in food and beverage cans and other containers

  • TIN PEST

A polymorphic modification of tin that causes it to crumble into a powder known as gray tin. It is generally accepted that the maximum rate of transformation occurs at about - 40 �C ( - 40 �F), but transformation can occur as high as about 13 �C (55 �F).

  • TIN PLATE

Thin sheet steel with a very thin coating of metallic tin. Tin plate is used primarily in canmaking

  • TIN SWEAT

See sweat.

  • TIN/CHROME PLATING

A plating process whereby the molecules from the positively charged tin or chromium anode attach to the negatively charged sheet steel. The thickness of the coating is readily controlled through regulation of the voltage and speed of the sheet through the plating area

  • TIN-FREE STEEL

Chromium-coated steel. Because it is used in food cans just like tin plate, it ironically is classified as a tin mill product. Tin-free steel is easier to recycle because tin will contaminate scrap steel in even small concentrations

  • TINNING

Coating metal with a very thin layer of molten solder or brazing filler metal.

  • TIR

Abbreviation for total indicator reading.

  • TIV

Abbreviation for total indicator variation.

  • TOE CRACK

Abase-metal crack at the toe of weld.

  • TOE OF WELD

The junction between the face of a weld and the base metal. See sketch accompanying fillet weld.

  • TOGGLE PRESS

A mechanical press in which the slide is actuated by one or more toggle links or mechanisms.

  • TOLERANCE

The specified permissible deviation from a specified nominal dimension, or the permissible variation in size or other quality characteristic of a part.

  • TOLERANCE LIMITS

The boundaries that define the range of permissible variation in size or other quality characteristic of a part.

  • TOLERANCES

A customer's specifications can refer to dimensions or to the chemical properties of steel ordered. The tolerance measures the allowable difference in product specifications between what a customer orders and what the steel company delivers. There is no standard tolerance because each customer maintains its own variance objective. Tolerances are given as the specification, plus or minus an error factor; the smaller the range, the higher the cost

  • TOLL PROCESSING

The act of processing steel for a fee ("toll"). Owners of the steel sheet may not possess the facilities to perform needed operations on the material (or may not have the open capacity). Therefore, another steel mill or service center will slit, roll, coat, anneal, or plate the metal for a fee

  • TON

Unit of measure for steel scrap and iron ore

  • TONG HOLD

The portion of a forging billet, usually on one end, that is gripped by the operator's tongs. It is removed from the part at the end of the forging operation. Common to drop-hammer and press-type forging.

  • TOOL STEEL

Any of a class of carbon and alloy steels commonly used to make tools. Tool steels are characterized by high hardness and resistance to abrasion, often accompanied by high toughness and resistance to softening at elevated temperature. These attributes are generally attained with high carbon and alloy contents.

  • TOOL STEELS

Steels that are hardened for the use in the manufacture of tools and dies

  • TOOTH

(1) A projection on a multipoint tool (such as on a saw, milling cutter or file) designed to produce cutting. (2) A projection on the periphery of a wheel or segment thereof (as on a gear, spline or sprocket, for example), designed to engage another mechanism and thereby transmit force or motion, or both. A similar projection on a flat member such as a rack.

  • TOOTH POINT

On a face mill, the chamfered cutting edge of the blade, to which a flat is sometimes added to produce a shaving effect and to improve finish. See sketch accompanying face mill.

  • TOP-AND-BOTTOM PROCESS

A process for separating copper and nickel, in which their molten sulfides are separated into two liquid layers by the addition of sodium sulfide. The lower layer holds most of the nickel.

  • TORCH

A gas burner used to solder, braze, weld or cut metals. For brazing or welding, it has two gas feed lines: one for fuel, such as acetylene or hydrogen, the other for oxygen. For cutting, there may be an additional feed line for oxygen. See oxygen cutting.

  • TORCH BRAZING

Brazing in which the heat is supplied by a fuel gas flame emanating from a torch.

  • TORSION

A twisting action resulting in shear stresses and strains.

  • TORSIONAL MOMENT

In a body being twisted, the algebraic sum of the couples or the moments of the external forces about the axis of twist, or both.

  • TOTAL CARBON

The sum of the free and combined carbon (including carbon in solution) in a ferrous alloy.

  • TOTAL CYANIDE

Cyanide content of an electroplating bath (including both simple and complex ions).

  • TOTAL INDICATOR READING

See preferred term, total indicator variation.

  • TOTAL INDICATOR VARIATION

The difference between the maximum and minimum indicator readings during a checking cycle.

  • TOUGH PITCH COPPER

Copper containing from 0.02 to 0.05percent oxygen, obtained by refining copper in a reverberatory furnace.

  • TOUGHNESS

Ability of a metal to absorb energy and deform plastically before fracturing. It is usually measured by the energy absorbed in a notch impact test, but the area under the stress-strain curve in tensile testing is also a measure of toughness.

  • TRADE CASE

A type of lawsuit filed by United States companies against their foreign counterparts in response to imports at prices lower than those in the U.S. market. Sanctions can be imposed by the International Trade Commission and the Commerce Department on foreign producers involved in dumping and government subsidization, if domestic manufacturers can prove material damage to their results

  • TRAFFIC MARK

See abrasion.

  • TRAMP ALLOYS

Residual alloying elements that are introduced into steel when unidentified alloy steel is present in the scrap charge to a steelmaking furnace.

  • TRANSCRYSTALLINE

Same as intracrystalline

  • TRANSFERENCE

The movement of ions trough the electrolyte associated with the passage of the electric current.Also called transport or migration.

  • TRANSFERENCE NUMBER

The proportion of total electroplating current carried ions of a given kind. Also called transport number.

  • TRANSFORMATION RANGES

Those ranges of temperature within which a phase forms during heating and transforms during cooling. The two ranges are distinct, sometimes overlapping but never coinciding. The limiting temperatures of the ranges depend on the composition of the alloy and on the rate of change of temperature, particularly during cooling. See transformation temperature.

  • TRANSFORMATION TEMPERATURE

The temperature at which a change in phase occurs. The term is sometimes used to denote the limiting temperature of a transformation range. The following symbols are used for iron and steels:

  • TRANSFORMATION-INDUCED PLASTICITY

A phenomenon, occurring chiefly in certain highly alloyed steels that have been heat treated to produce metastable austenite or metastable austenite plus martensite, whereby, on subsequent deformation, part of the austenite undergoes strain-induced transformation to martensite. Steels capable of transforming in this manner, commonly referred to as TRIP steels, are highly plastic after heat treatment, but exhibit a very high rate of strain hardening and thus have high tensile and yield strengths after plastic deformation at temperatures between about 20 and 500 �C (70 and 930 �F). Cooling to -195 �C ( - 320 �F) may or may not be required to complete the transformation to martensite. Tempering usually is done following transformation.

  • TRANSGRANULAR

Same as intracrystalline.

  • TRANSITION LATTICE

An unstable crystallographic configuration that forms as an intermediate step in a solid-state reaction such as precipitation from solid solution or eutectoid decomposition.

  • TRANSITION METAL

A metal in which the available electron energy levels are occupied in such a way that the d-band contains less than its maximum number of ten electrons per atom; for example, iron, cobalt, nickel, and tungsten. The distinctive properties of the transition metals result from the incompletely filled d-levels.

  • TRANSITION POINT

At a stated pressure, the temperature (or at a stated temperature, the pressure) at which two solid phases exist in equilibrium; that is, an allotropic transformation temperature (or pressure).

  • TRANSITION TEMPERATURE

(1) An arbitrarily defined temperature that lies within the temperature range in which metal fracture characteristics (as usually determined by tests of notched specimens) change rapidly, such as from primarily fibrous (shear) to primarily crystalline (cleavage) fracture. Commonly used definitions are "transition temperature for 50percent cleavage fracture", "10 ft lb transition temperature," and "transition temperature for half maximum energy". (2) Sometimes used to denote an arbitrarily defined temperature within a range in which the ductility changes rapidly with temperature.

  • TRANSITIONAL FIT

A fit that may have either clearance or interference resulting from specified tolerances on hole and shaft.

  • TRANSPORT

See transference.

  • TRANSPORT NUMBER

Same as transference number.

  • TRANSVERSE

Literally, "across", usually signifying a direction or plane perpendicular to the direction of working. In rolled plate or sheet, the direction across the width is often called long transverse, and the direction through the thickness, short transverse.

  • TRANSVERSE ROLLING MACHINE

Equipment for producing complex preforms or finished forgings from round billets inserted transversely between two or three rolls that rotate in the same direction and drive the billet. The rolls, carrying replaceable die segments with appropriate impressions, make several revolutions for each rotation of the workpiece.

  • TREES

Visible projections of electrodeposited metal formed at sites of high current density.

  • TRIAXIAL STRESS

A state of stress in which none of the three principal stresses is zero.

  • TRIAXIALITY

In a triaxial stress state, the ratio of the smallest to the largest principal stress, all stresses being tension.

  • TRIBOLOGY

The science and art concerned with the design, friction, lubrication and wear of contacting surfaces that move relative to each other (as in bearings, cams or gears, for example).

  • TRIMMER BLADES

The portion of trimmers through which a forging is pushed to shear off the flash.

  • TRIMMER PUNCH

The upper portion of trimmers, which comes in contact with a forging and pushes it through the trimmer blades. The lower end of the trimmer punch is generally shaped to fit the surface of the forging against which it pushes.

  • TRIMMERS

The combination of trimmer punch, trimmer blades and perhaps trimmer shoe used to remove the flash from the forging.

  • TRIMMING

(1) In drawing, shearing the irregular edge of the drawn part. (2) In forging or die casting, removing any parting-line flash and gates from the part by shearing. (3) In casting, the removal of gates, risers and fins.

  • TRIMMING SHOE

The holder used to support a trimmer. Sometimes called trimming chair.

  • TRIP STEEL

A commercial steel product exhibiting transformation-induced plasticity.

  • TRIPLE POINT

A point on a phase diagram where three phases of a substance coexist in equilibrium.

  • TRIPLE-ACTION PRESS

A mechanical or hydraulic press having three slides with three motions properly synchronized for triple-action drawing, redrawing and forming. Usually, two slides - the blank-holder slide and the plunger - are located above and a lower slide is located within the bed of the press.

  • TRIPOLI

Friable and dustlike silica used as an abrasive.

  • TRUE CAPACITY

Volume at full utilization, allowing for the maintenance of equipment and reflecting current material constraints. (Bottlenecks of supply and distribution can change over time-capacity will expand or reduce.)

  • TRUE CURRENT DENSITY

See preferred term, local current density.

  • TRUE RAKE

See preferred term, effective rake.

  • TRUE STRAIN

See strain.

  • TRUE STRESS

See stress.

  • TUBE REDUCING

Reducing both the diameter and wall thickness of tubing with a mandrel and a pair of rolls with tapered grooves. The Rockrite process uses a fixed tapered mandrel, and the rolls reciprocate along the tubing with corresponding reversal in rotation. Roll reliefs at the initial and final diameters permit, respectively, advance and rotation of the tubing. The Pilger process uses a uniform rod (broach), which reciprocates with the tubing. The fixed rolls rotate continuously. During the gap in each revolution, the tubing is advanced and rotated and then, upon roll contact, reduced and partially returned.

  • TUBE SINKING

Drawing tubing through a die or passing it through rolls without the use of an interior tool (such as a mandrel or plug) to control inside diameter. Sinking generally produces a tube of increased wall thickness and length.

  • TUBE STOCK

A semifinished tube suitable for subsequent reduction and finishing.

  • TUBING

When referring to OCTG, tubing is a separate pipe used within the casing to conduct the oil or gas to the surface. Depending on conditions and well life, tubing may have to be replaced during the operational life of a well

  • TUMBLING

Rotating workpieces, usually castings or forgings, in a barrel partly filled with metal slugs or abrasives, to remove sand, scale or fins. It may be done dry, or with an aqueous solution added to the contents of the barrel. Sometimes called rumbling or rattling.

  • TUNDISH

The shallow refractory-lined basin on top of the continuous caster. It receives the liquid steel from the ladle, prior to the cast, allowing the operator to precisely regulate the flow of metal into the mold

  • TUNGSTEN INERT-GAS WELDING

See preferred term, gas tungsten-arc welding.

  • TUNNEL FURNACE

Type of furnace whereby stock to be heated is placed upon cars, which are then pushed or pulled slowly through the furnace

  • TURK'S-HEAD ROLLS

Four undriven working rolls, arranged in a square or rectangular pattern, through which strip, wire or tubing is drawn to form square or rectangular sections.

  • TURNING

Removing material by forcing a cutting tool (often a single-point tool) against the surface of a rotating workpiece. The tool may or may not be moved toward or along the axis of rotation while it cuts away material.

  • TUYERE

An opening in the shell and refractory lining of a furnace, through which air is forced.

  • TWIN

Two portions of a crystal having a definite crystallographic relationship; one may be regarded as the parent, the other as the twin. The orientation of the twin is either a mirror image of the orientation of the parent about a "twinning plane" or an orientation that can be derived by rotating the twin portion about a "twinning axis". See also annealing twin, mechanical twin.

  • TWIST BOUNDARY

A subgrain boundary consisting of an array of screw dislocations.

  • TWO-HIGH MILL

A type of rolling mill in which only two rolls, the working rolls, are contained in a single housing. Compare with four-high mill, cluster mill.

  • TYPE 304

The most commonly specified austenitic (chromium-nickel stainless class) stainless steel, accounting for more than half of the stainless steel produced in the world. This grade withstands ordinary corrosion in architecture, is durable in typical food processing environments, and resists most chemicals. Type 304 is available in virtually all product forms and finishes

  • TYPE 316

Austenitic (chromium-nickel stainless class) stainless steel containing 2percent-3percent molybdenum (whereas 304 has none). The inclusion of molybdenum gives 316 greater resistance to various forms of deterioration

  • TYPE 409

Ferritic (plain chromium stainless category) stainless steel suitable for high temperatures. This grade has the lowest chromium content of all stainless steels and thus is the least expensive

  • TYPE 410

The most widely used martensitic (plain chromium stainless class with exceptional strength) stainless steel, featuring the high level of strength conferred by the martensitics. It is a low-cost, heat-treatable grade suitable for non-severe corrosion applications

  • TYPE 430

The most widely used ferritic (plain chromium stainless category) stainless steel, offering general-purpose corrosion resistance, often in decorative applications

  • TYPE METAL

Any of a series of alloys containing 54 to 95percent Pb, 2 to 28percent Sb and 2 to 20percent Sn, used to make printing type.

  • U-BEND DIE

A die, commonly used in press-brake forming, machined horizontally with a square or rectangular cross-sectional opening that provides two edges over which metal is drawn into a channel shape.

  • UGINE-SEJOURNET PROCESS

A direct extrusion process for metals that uses molten glass to insulate the hot billet and to act as a lubricant.

  • ULTIMATE STRENGTH

The maximum conventional stress (tensile, compressive or shear) that a material can withstand.

  • ULTRASONIC BEAM

A beam of acoustical radiation with a frequency higher than the frequency range for audible sound - that is, above about 20 kHz.

  • ULTRASONIC CLEANING

Immersion cleaning aided by ultrasonic waves that cause microagitation.

  • ULTRASONIC FREQUENCY

A frequency, associated with elastic waves, that is greater than the highest audible frequency, generally regarded as being higher than 15 kHz.

  • ULTRASONIC MACHINING

A form of abrasive machining in which a tool vibrating at ultrasonic frequency causes a grit-loaded slurry to impinge on the surface of a workpiece, and thereby remove material.

  • ULTRASONIC TESTING

A nondestructive test applied to sound-conductive materials having elastic properties for the purpose of locating inhomogeneities or structural discontinuities within a material by means of an ultrasonic beam.

  • ULTRASONIC WELDING

A solid state process in which materials are welded by locally applying high-frequency vibratory energy to a joint held together under pressure.

  • UNDERBEAD CRACK

A subsurface crack in the base metal near a weld.

  • UNDERCOOLING

Same as supercooling.

  • UNDERCUT

(1) In weldments, a groove melted into the base metal adjacent to the toe of a weld and left unfilled. (2) For castings or forgings, same as back draft.

  • UNDERDRAFT

A condition wherein a metal curves downward on leaving a set of rolls because of higher speed in the upper roll.

  • UNDERFILL

A portion of a forging that has insuffficient metal to give it the true shape of the impression.

  • UNDERSTRESSING

Applying a cyclic stress lower than the endurance limit. This may improve fatigue life if the member is later cyclically stressed at levels above the endurance limit.

  • UNFAIR TRADE SUIT

A type of lawsuit filed by U.S. companies against their foreign counterparts in response to imports at prices being lower than those in the prices in the U.S. market. Sanctions can be imposed by the ITC and the Commerce Department on foreign producers involved in dumping and government subsidization, if domestic manufacturers can prove material injury

  • UNIAXIAL STRESS

A state of stress in which two of the three principal stresses are zero.

  • UNIFORM STRAIN

The strain occurring prior to the beginning of localization of strain (necking); the strain to maximum load in the tension test.

  • UNIT CELL

In crystallography, the fundamental building block of a space lattice. Space lattices are constructed by stacking identical unit cells - that is, parallelepipeds of identical size, shape and orientation, each having a lattice point at every corner - face to face in perfect three-dimensional alignment.

  • UNIT DIE

A die block that contains several cavity inserts for making different kinds of castings.

  • UNIT POWER

The net amount of power required during machining to remove a unit volume of metal in unit time.

  • UNIVERSAL FORGING MILL

A combination of four hydraulic presses arranged in one plane equipped with billet manipulators and automatic controls, used for radial or draw forging.

  • UNIVERSAL MILL

A rolling mill in which rolls with a vertical axis roll the edges of the metal stock between some of the passes through the horizontal rolls.

  • UPSET

(1) The localized increase in cross-sectional area of a workpiece or weldment resulting from the application of pressure during mechanical fabrication or welding. (2) That portion of a welding cycle during which the cross-sectional area is increased by the application of pressure.

  • UPSET FORGING

A forging obtained by upset of a suitable length of bar, billet or bloom.

  • UPSET WELDING

A resistance welding process in which the weld is produced, simultaneously over the entire area of abutting surfaces or progressively along a joint, by applying mechanical force (pressure) to the joint, then causing electrical current to flow across the joint to heat the abutting surfaces. Pressure is maintained throughout the heating period. See also open-gap upset welding.

  • UPSETTER

A horizontal mechanical press used to make parts from bar stock or tubing by upset forging, piercing, bending or otherwise forming in dies. Also known as a header.

  • UPSETTING

Working metal so that the cross-sectional area of a portion or all of the stock is increased. See also heading.

  • UPSLOPE TIME

In resistance welding, time associated with current increase using slope control.

  • VACANCY

A type of lattice imperfection in which an individual atom site is temporarily unoccupied. Diffusion (of other than interstitial solutes) is generally visualized as the shifting of vacancies.

  • VACUUM ARC REMELTING

A consumable electrode remelting process in which heat is generated by an electric arc between the electrode and the ingot. The process is performed inside a vacuum chamber. Exposure of the droplets of molten metal to the reduced pressure reduces the amount of dissolved gas in the metal. Sometimes abbreviated VAR.

  • VACUUM DEGASSING

An advanced steel refining facility that removes oxygen, hydrogen and nitrogen under low pressures (in a vacuum) to produce ultra-low-carbon steel for demanding electrical and automotive applications. Normally performed in the ladle, the removal of dissolved gases results in cleaner, higher-quality, more pure steel (see Ladle Metallurgy)

  • VACUUM DEPOSITION

Condensation of thin metal coatings on the cool surface of work in a vacuum.

  • VACUUM FUSION

An analytic technique for determining the amount of gases in metals; ordinarily used for hydrogen and oxygen, and sometimes for nitrogen. Applicable to many metals, but not to alkali or alkaline earth metals.

  • VACUUM INDUCTION MELTING

A process for remelting and refining metals in which the metal is melted inside a vacuum chamber by induction heating. The metal may be melted in a crucible, then poured into a mold. The process may also be operated in a configuration similar to that used in consumable electrode remelting except that the heat is supplied by an induction heating coil rather than from the passage of electric current through the electrode. Sometimes abbreviated VIM.

  • VACUUM MELTING

Melting in a vacuum to prevent contamination from air, as well as to remove gases already dissolved in the metal; the solidification may also be carried out in a vacuum or at low pressure.

  • VACUUM OXYGEN DECARBURIZATION (VOD)

WHAT. Process for further refinement of stainless steel through reduction of carbon content. WHY. The amount of carbon in stainless steel must be lower than that in carbon steel or lower alloy steel (i.e., steel with alloying element content below 5percent). While electric arc furnaces (EAF) are the conventional means of melting and refining stainless steel, VOD is an economical supplement, as operating time is reduced and temperatures are lower than in EAF steelmaking. Additionally, using VOD for refining stainless steel increases the availability of the EAF for melting purposes. HOW. Molten, unrefined steel is transferred from the EAF into a separate vessel, where it is heated and stirred by an electrical current while oxygen enters from the top of the vessel. Substantial quantities of undesirable gases escape from the steel and are drawn off by a vacuum pump. Alloys and other additives are then mixed in to refine the molten steel further

  • VAPOR BLASTING

Same as liquid honing.

  • VAPOR DEGREASING

Degreasing of work in the vapor over a boiling liquid solvent, the vapor being considerably heavier than air. At least one constituent of the soil must be soluble in the solvent. Modifications of this cleaning process include vapor-spray-vapor; warm liquid-vapor; boiling liquid-warm liquid-vapor; and ultrasonic degreasing.

  • VAPOR PLATING

Deposition of a metal or compound on a heated surface by reduction or decomposition of a volatile compound at a temperature below the melting points of the deposit and the base material. The reduction is usually accomplished by a gaseous reducing agent such as hydrogen. The decomposition process may involve thermal dissociation or reaction with the base material. Occasionally used to designate deposition on cold surfaces by vacuum evaporation - see vacuum deposition.

  • V-BEND DIE

A die commonly used in press-brake forming, usually machined with a triangular cross-sectional opening to provide two edges as fulcrums for accomplishing threepoint bending.

  • VEGARD'S LAW

The relationship that states that the lattice parameters of substitutional solid solutions vary linearly between the values for the components, with composition expressed in atomic percentage.

  • VEINING

A type of subboundary structure that can be delineated because of the presence of a greater than average concentration of precipitate or possibly solute atoms.

  • VENT

A small opening in a mold for the escape of gases.

  • VERMICULAR IRON

Same as compacted graphite cast iron.

  • VERTICAL-POSITION WELDING

Welding where the axis of the weld is essentially vertical.

  • VIBRATORY FINISHING

A process for deburring and surface finishing in which the product and an abrasive mixture are placed in a container and vibrated.

  • VICKERS HARDNESS TEST

An indentation hardness test employing a 136� diamond pyramid indenter (dickers) and variable loads enabling the use of one hardness scale for all ranges of hardness from very soft lead to tungsten carbide.

  • VIRGIN METAL

Same as primary metal.

  • VOLTAGE EFFICIENCY

The ratio, usually expressed as a percentage, of the equilibrium-reaction potential in a given electrochemical process to the bath voltage.

  • VOLUNTARY RESTRAINT AGREEMENTS (VRAS)

Trading partners are allowed to export steel "illegally" - that is, "dump" or receive subsidies - with no consequences, as long as such exports are kept below a certain level; this provision cannot be used with WTO countries

  • WALKING BEAM FURNACE

A type of continuous reheat furnace in which the billet or slab moves through distinct heating zones within the furnace: By controlling the speed through the zones, steelmakers can achieve precise rolling temperatures and consume less fuel during operation

  • WALLNER LINES

A distinct pattern of intersecting sets of parallel lines, usually producing a set of V-shaped lines, sometimes observed when viewing brittle fracture surfaces at high magnifications in an electron microscope. Wallner lines are attributed to interaction between a shock wave and a brittle crack front propagating at high velocity. Sometimes Wallner lines are misinterpreted as fatigue striations.

  • WANDERING SEQUENCE

Same as random sequence.

  • WARM WORKING

Plastically deforming metal at a temperature above ambient (room) temperature but below the temperature at which the material undergoes recrystallization.

  • WASH

(1) A coating applied to the face of a mold prior to casting. (2) An imperfection at a cast surface similar to a cut.

  • WASH METAL

Molten metal used to wash out a furnace, ladle or other container.

  • WATER BREAK

The appearance of a discontinuous film of water on a surface signifying nonuniform wetting and usually associated with a surface contamination.

  • WAVINESS

A wave-like variation from a perfect surface, generally much larger and wider than the roughness caused by tool or grind marks.

  • WEAR PAD

In forming, an expendable rubber or rubberlike material of nominal thickness that is placed against the diaphragm to lessen the wear on it. See diaphragm, (2).

  • WEAVE BEAD

A weld bead made with oscillations transverse to the axis of the weld. Contrast with stringer bead.

  • WEB

(1) For twist drills and reamers, the central portion of the tool body that joins the lands. (2) In forging, the thin section of metal remaining at the bottom of a cavity or depression or at the location of the top and bottom punches. The former type may be removed by piercing or machining; the latter, by the trim punch. (3) A plate or thin portion between stiffening ribs or flanges, as in an I-beam, H-beam or other similar section.

  • WEIGHT PERCENT

Percentage composition by weight. Contrast with atomic percent.

  • WELD

A union made by welding.

  • WELD BEAD

A deposit of filler metal from a single welding pass.

  • WELD CRACK

A crack in weld metal.

  • WELD DELAY TIME

In spot, seam or projection welding, the time current is delayed with respect to starting the forge delay timer in order to synchronize the forging pressure and the welding heat.

  • WELD GAGE

A device for checking shape and size of welds.

  • WELD INTERVAL

The total heat and cool times in making one multiple-impulse resistance weld.

  • WELD LINE

The junction of the weld metal and the base metal, or the junction of the base-metal parts when filler metal is not used.

  • WELD METAL

That portion of a weld that has been melted during welding.

  • WELD NUGGET

The weld metal in spot, seam or projection welding.

  • WELD TIME

In single-impulse and flash welding, the time that the welding current is applied to the work.

  • WELD TIMER

A device used in resistance welding to control the weld time only.

  • WELDABILITY

A specific or relative measure of the ability of a material to be welded under a given set of conditions. Implicit in this definition is the ability of the completed weldment to fulfill all service designed into the part.

  • WELDER

A person who makes welds using manual or semiautomatic equipment. Formerly used as a synonym for welding machine.

  • WELDING

(1) Joining two or more pieces of material by applying heat or pressure, or both, with or without filler material, to produce a localized union through fusion or recrystallization across the interface. The thickness of the filler material is much greater than the capillary dimensions encountered in brazing. (2) May also be extended to include brazing and soldering.

  • WELDING CURRENT

The current flowing through a welding circuit during the making of a weld. In resistance welding, the current used during preweld or postweld intervals is excluded.

  • WELDING CYCLE

The complete series of events involved in making a resistance weld. Also applies to semiautomatic mechanized fusion welds.

  • WELDING FORCE

Same as electrode force in resistance welding.

  • WELDING GENERATOR

A generator used for supplying current for welding.

  • WELDING GROUND

Same as work lead.

  • WELDING LEADS

The electrical cables that serve as either work lead or electrode lead of an arc welding circuit.

  • WELDING MACHINE

Equipment used to perform the welding operation - for example, spot welding machine, arc welding machine, seam welding machine.

  • WELDING PROCEDURE

The detailed methods and practices, including joint preparation and welding procedures, involved in the production of a weld meet.

  • WELDING ROD

Welding or brazing filler metal, usually in rod or wire form, but not a consumable electrode. Welding rod does not conduct the electric current to an arc, and may be either fed into the weld puddle or preplaced in the joint.

  • WELDING SEQUENCE

The order in which the various component parts of a weldment or structure are welded.

  • WELDING STRESS

Residual stress caused by localized heating and cooling during welding.

  • WELDING TECHNIQUE

The details of a welding operation that, within the limitations of a welding procedure, are performed by the welder.

  • WELDING TIP

(1) A torch tip designed for welding. (2) The electrode tip that contacts the work in resistance spot welding.

  • WELD-INTERVAL TIMER

A device used in resistance welding to control heat and cool times and weld interval when making multiple-impulse welds singly or simultaneously.

  • WELDMENT

An assembly whose component parts are joined by welding.

  • WELDOR

(obsolete) Formerly used to designate a person who makes welds. See preferred term, welder.

  • WENSTROM MILL

A rolling mill similar to a universal mill but where the edges and sides of a rolled section are acted on simultaneously.

  • WET BLASTING

A process for cleaning or finishing by means of a slurry of abrasive in water directed at high velocity against the workpieces.

  • WETTING

A condition in which the interfacial tension between a liquid and a solid is such that the contact angle is 0� to 90�.

  • WETTING AGENT

A surface-active agent that produces wetting by decreasing the cohesion within the liquid.

  • WHISKERS

Metallic filamentary growths, often microscopic, sometimes formed during electrodeposition and sometimes spontaneously during storage or service, after finishing.

  • WHITE CAST IRON

Cast iron that shows a white fracture because the carbon is in combined form.

  • WHITE HEART MALLEABLE

See malleable cast iron.

  • WHITE METAL

(1) A general term covering a group of white-colored metals of relatively low melting points (lead, antimony, bismuth, tin, cadmium and zinc) and of the alloys based on these metals. (2) A copper matte of about 77percent Cu obtained from smelting of sulfide copper ores.

  • WHITE RUST

Zinc oxide; the powdery product of corrosion of zinc or zinccoated surfaces.

  • WIDE FLANGE BEAM

A structural steel section on which the flanges are not tapered, but have equal thickness from the tip to the web and are at right angles to the web. Wide-flange beams are differentiated by the width of the web, which can range from 3 inches to more than 40 inches, and by the weight of the beam, measured in pounds per foot

  • WIDMANSTATTEN STRUCTURE

A structure characterized by a geometrical pattern resulting from the formation of a new phase along certain crystallographic planes of the parent solid solution. The orientation of the lattice in the new phase is related crystallographically to the orientation of the lattice in the parent phase. The structure was originally observed in meteorites, but is readily produced in many other alloys by appropriate heat treatment.

  • WIDTHS

The lateral dimension of rolled steel, as opposed to the length or the gauge (thickness). If width of the steel strip is not controlled during rolling, the edges must be trimmed

  • WILDNESS

A condition that exists when molten metal, during cooling, evolves so much gas that it becomes violently agitated, forcibly ejecting metal from the mold or other container.

  • WILLIAMS RISER

An atmospheric riser.

  • WINNING

Recovering a metal from an ore or chemical compound using any suitable hydrometallurgical, pyrometallurgical or electrometallurgical method.

  • WIPED COAT

A hot dipped galvanized coating where virtually all free zinc is removed by wiping prior to solidification, leaving only a thin zinc-iron alloy layer.

  • WIPED JOINT

A joint wherein filler metal is applied in liquid form and distributed by mechanical action.

  • WIPER FORMING

A method of curving bars, tubes or rolled or extruded sections, in which the stock is bent so that it conforms to a fixed form block. Stock is clamped to the form block, then bent by applying force through a wiper block, shoe or roll that is moved along the periphery of the form block. Sometimes called compression forming. Contrast with draw forming.

  • WIPING EFFECT

Activation of a metal surface by mechanically rubbing or wiping to enhance the formation of conversion coatings, such as phosphate coatings.

  • WIRE

(1) A thin flexible, continuous length of metal, usually of circular cross section, and usually produced by drawing through a die. See also flat wire. (2) A length of single metallic electrical conductor, it may be of solid, stranded or tinsel construction, and may be either bare or insulated.

  • WIRE BAR

A cast shape, particularly of tough pitch copper, that has a cross section approximately square with tapered ends, designed for hot rolling to rod for subsequent drawing into wire.

  • WIRE DRAWING

Reducing the cross section of wire by pulling it through a die. See Taylor process.

  • WIRE ROD

Hot rolled coiled stock that is to be cold drawn into wire.

  • WIRING

Formation of a curl along the edge of a shell, tube or sheet and insertion of a rod or wire within the curl for stiffening the edge. See curling.

  • WOOD FLOUR

A pulverized wood product used in the foundry to furnish a reducing atmosphere in the mold, help overcome sand expansion, increase flowability, improve casting finish and provide easier shakeout.

  • WOODY STRUCTURE

A macrostructure particulary found in wrought iron and in extruded rods of aluminum alloys that shows elongated surfaces of separation when fractured.

  • WORK ANGLE

In arc welding, the angle between the electrode and one member of the joint, taken in a plane normal to the weld axis.

  • WORK HARDENING

Same as strain hardening.

  • WORK LEAD

The electrical conductor connecting the source of arc welding current to the work. Also called work connection, welding ground or ground lead.

  • WORK RULES

The division of jobs into separate crafts and specific guidelines for work in the labor contract. These provisions define the duties of a specific job, and management must negotiate with the labor representative to make any changes

  • WORM

An exudation (sweat) of molten metal forced through the top crust of solidifying metal by gas evolution. See also zinc worms.

  • WRAP FORMING

See stretch forming.

  • WRINGING FIT

A fit of nominally zero allowance.

  • WRINKLING

A wavy condition obtained in drawing, in the area of the metal that passes over the draw radius. Wrinkling may also occur in other forming operations when unbalanced compressive forces are set up.

  • WROUGHT IRON

A commercial iron consisting of slag (iron silicate) fibers entrained in a ferrite matrix.

  • X-RAY

Electromagnetic radiation, of wavelength less than about 50 nm, emitted as the result of deceleration of fast-moving electrons (bremsstrahlung, continuous spectrum) or decay of atomic electrons from excited orbital states (characteristic radiation); specifically, the radiation produced when an electron beam of sufficient energy impinges on a target of suitable material.

  • Y-BLOCK

A single keel block.

  • YIELD

The ratio of the quantity of finished shipments to the total raw steel produced, adjusted for changes in inventory and any slabs that are purchased from outside. Yield has significantly improved during the past decade, primarily as the result of the industry's conversion to continually cast steel, whose yield is superior to that of traditional ingot teeming

  • YIELD POINT

The first stress in a material, usually less than the maximum attainable stress, at which an increase in strain occurs without an increase in stress. Only certain metals exhibit a yield point. If there is a decrease in stress after yielding, a distinction may be made between upper and lower yield points.

  • YIELD STRENGTH

The stress at which a material exhibits a specified deviation from proportionality of stress and strain. An offset of 0.2percent is used for many metals. Compare with tensile strength.

  • YOUNG'S MODULUS

See modulus of elasticity.

  • ZINC WORMS

Surface imperfections, characteristic of high-zinc brass castings, that occur when zinc vapor condenses at the mold/metal interface, where it is oxidized and then becomes entrapped in the solidifying metal.

  • ZIRCON SAND

A very refractory mineral, composed chiefly of zirconium silicate; it has low thermal expansion and high thermal conductivity.

  • Z-MILL

(See Sendzimir Mill)

  • ZONE MELTING

Highly localized melting, usually by induction heating, of a small volume of an otherwise solid piece, usually a rod. By moving the induction coil along the rod, the melted zone can be transferred from one end to the other. In a binary mixture where there is a large difference in composition on the liquidus and solidus lines, high purity can be attained by concentrating one of the constituents in the liquid as it moves along the rod.