Glossary of Metalworking Terms

Glossary

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Glossary of Metalworking Terms Abrasion - The process of rubbing, grinding, or wearing away by friction. Abrasion-Resistant Steels - A family of steel products developed for those applications involved in sliding and/or impact abrasion. Abrasive - A substance capable of grinding away another material. Accordion Reed Steel - Hardened, tempered, polished and blued or yellow flat steel with dressed edges. Carbon content about 1.00. Material has to possess good flatness, uniform hardness and high elasticity. 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. Steel produced in a furnace with an acid lining, i.e. consisting of a siliceous refractory and under a siliceous slag. With an acid slag, carbon, silicon and manganese only are removed so that the pig iron must not contain sulfur and phosphorus in percentages exceeding those permissible for the specification being made. Most steel manufactured today is in furnaces with basic linings. Acid-Brittleness - Brittleness resulting from pickling steel in acid; hydrogen, formed by the interaction between iron and acid, is partially absorbed by the metal, causing acid brittleness. Acid Dipped - Dry Rolled Finish. Produced by dry cold rolling bichromate dipped alloy with polished rolls resulting in a burnished appearance and retaining the color obtained by dipping (True Metal Color). Acid-Process - A process of making steel, either Bessemer, open-hearth or electric, in which the furnace is lined with a siliceous refractory and for which low phosphorus pig iron is required as this element is not removed. Activation - The changing of the passive surface of a metal to a chemically active state. Contrast with passivation. Age Hardening - Hardening by aging, usually after rapid cooling or cold working. The term as applied to soft, or low carbon steels, relates to a wide variety of commercially important, slow, gradual changes that take place in properties of steels after the final treatment. These changes, which bring about a condition of increased hardness, elastic limit, and tensile strength with a consequent loss in ductility, occur during the period in which the steel is at normal temperatures. Aging - A change in properties that occurs at ambient or moderately elevated temperatures after hot working or a heat-treating operation (quench aging in ferrous 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 does not involve a change in chemical composition. In a metal or alloy, a change in properties that generally occurs slowly at room temperature and more rapidly at higher temperatures.

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Air Cooling - Cooling of the heated metal, intermediate in rapidity between slow furnace cooling and quenching, in which the metal is permitted to stand in the open air. 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. Such steels attain their martensitic structure without going through the quenching process. Additions of chromium, nickel, molybdenum and manganese are effective toward this end. 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. AISI Steels - Steels of the American Iron and Steel Institute. Common and alloy steels have been numbered in a system essentially the same as the SAE. The AISI system is more elaborate than the SAE in that all numbers are preceded by letters: A represents basic openhearth alloy steel, B acid Bessemer carbon steel, C basic open-hearth carbon steel, CB either acid Bessemer are basic open-hearth carbon steel, E electric furnace alloy steel. Alclad - Composite sheet produced by bonding either corrosion-resistant aluminum alloy or aluminum of high purity to base metal of structurally stronger aluminum alloy. The coatings are anodic to the core so they protect exposed areas of the core electrolytically during exposure to corrosive environment. Alkaline Cleaner - Uses an alkaline solution, usually sodium hydroxide, to clean residual oils and iron fines left on the strip from the cold reduction process. Allotriomorph - A particle of a phase that has no regular external shape. Allotropy - The property whereby certain elements may exist in more than one crystal structure. The property possessed by certain elements to exist in two or more distinct forms that are chemically identical but have different physical properties. In the case of iron the crystal structure has one form at room temperature and another at high temperature. When heated above 910oC the atomic structure changes from body centered cubic to face centered cubic but reverts again when cooled. The allotropy of iron modifies the solubility of carbon, and it is because of this that steel can be hardened. Alloy - A substance having metallic properties and composed of two or more chemical elements of which at least one is a metal. Alloy Steel - Steel containing substantial quantities of elements other than carbon and the commonly accepted limited amounts of manganese, sulfur, silicon, and phosphorus. Addition of such alloying elements is usually for the purpose of increased hardness, strength or chemical resistance. The metals most commonly used for forming alloy steels are: nickel, chromium, silicon, manganese tungsten, molybdenum and vanadium, Low Alloy steels are usually considered to be those containing a total of less than 5% of such added constituents. Alloying Element - An element added to a metal, and remaining in the metal, that effects changes in structure and properties. Alpha Brass - A copper-zinc alloy containing up to 38% of zinc. Used mainly for cold working. Alpha Bronze - A copper-tin alloy consisting of the alpha solid solution of tin in copper. Commercial forms contain 4 or 5% of tin. This alloy is used in coinage, springs, turbine, blades, etc. Alpha Iron - The polymorphic form of iron, stable below 1670 (degrees) F. has a body


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centered cubic lattice, and is magnetic up to 1410 (degrees) F. Aluminizing - Forming an aluminum or aluminum alloy coating on a metal by hot dipping, hot spraying, or diffusion. Aluminum Al Atomic Number: 13 Atomic Weight: 26.981538 Melting Point: 933.437 K (660.323C or 1220.581F) Boiling Point: 2792 K (2519C or 4566F) Density: 2.70 grams per cubic centimeter Phase at Room Temperature: Solid A silvery white metal of valence 3. Ductile and malleable; stable against normal atmospheric corrosion, but attacked by both acids and alkalis. Aluminum is used extensively in articles requiring lightness, corrosion resistance, electrical conductivity, etc. Its principal functions as an alloy in steel making; (1) Deoxidizes efficiently. (2) Restricts grain growth (by forming dispersed oxides or nitrides) (3) Alloying element in nitriding steel. Aluminum is also used to deoxidize steel and control grain size. Grain size control is affected by forming a fine dispersion with nitrogen and oxygen, which restricts austenite grain growth. Aluminum is also an extremely effective nitride former in nitriding steels. Aluminum Killed Steel A steel where aluminum has been used as a deoxidizing agent. Amorphous - Noncrystalline. Analog - Full-body electromagnetic induction testing; a type of non-destructive test. Angstrom Unit - (A) A unit of linear measure equal to 10(-10)m, or 0.1 nm; not an accepted Si unit, but still sometimes used for small distances such as interatomic distances and some wavelengths. Anisotropy - The characteristics of exhibiting different values of a property in different directions with respect to a fixed reference system in the material. Annealing - (1) Heating to and holding at a suitable temperature and then cooling at a suitable rate, for such purposes as reducing hardness, improving machinability, facilitating cold working, producing a desired microstructure, or obtaining desired mechanical, physical, or other properties. When applicable, the following more specific terms should be used: black annealing, blue annealing, box annealing, bright annealing, flame annealing, graphitizing, intermediate annealing, isothermal annealing, malleableizing, process annealing, quench annealing, recrystallization annealing, and spheroids. When applied to ferrous alloys, the term annealing, without qualification, implies full annealing. When applied to nonferrous alloys, the term annealing implies a heat treatment designed to soften an age-hardened alloy by causing a nearly complete precipitation of the second phase in relatively coarse form. Any process of annealing will usually reduce stresses, but if the treatment is applied for the sole purpose of such relief, it should be designated stress relieving. (2) The process of heating and cooling a cold reduced sheet to induce softness and formability. Two types: box annealing (Cold Sheet Mill) and continuous annealing (Galvanize Mill) Automatic Gauge Control (AGC) Computerized systems used to control and maintain strip thickness; activated through x-ray measurement with feedback loops to control mill screw down pressures and/or speed. Annealing Twin - A twin formed in a metal during an annealing heat treatment.


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Anodizing (Aluminum Acid Oxide Coating) - A process of coating aluminum by anodic treatment resulting in a thin film of aluminum oxide of extreme hardness. A wide variety of dyes colored coatings are possible by impregnation in process. Arc Furnace - A steel melting furnace in which heat is generated by an arc between graphite electrodes and the metal. Both carbon and alloy steels are produced in electric arc furnaces and scrap rather than molten metal is used as the base material. Furnaces with capacities up to 200 tons are now in use. Arc Welding - A group of welding processes wherein the metal or metals being joined are coalesced by heating with an arc, with or without the application of pressure and with or without the use of filler metal. Artifact - In microscopy, a false structure introduced during preparation of a specimen. Artificial Aging - An aging treatment above room temperature. ASME - Abbreviation for Society of Automotive Engineers. This organization has specified common and alloy steels and copper base alloys in accordance with a numerical index system allowing approximation of the composition of the metal. The last two digits always indicate the carbon content, usually within 0.05%. See AISI-SAE specifications. An accelerated corrosion test in which the metal specimens are exposed to a fine mist of salt-water solution either continuously or intermittently. ASTM - Abbreviation for American Society For Testing Material. An organization for issuing standard specifications on materials, including metals and alloys. Atomic-Hydrogen Weld - Arc welding with heat from an arc between two tungsten or other suitable electrodes in a hydrogen atmosphere. The use of pressure and filler metal is optional. Attenuation - The fractional decrease of the intensity of an energy flux, including the reduction of intensity resulting from geometrical spreading, absorption, and scattering. Austenitic Grain Size - The size of the grains in steel heated into the austenitic region. Austempering - Quenching a ferrous alloy from a temperature above the transformation range, in a medium having a rate of heat abstraction high enough to prevent the formation of high-temperature transformation products, and then holding the alloy, until transformation is complete, at a temperature below that of pearlite formation and above that of martensite formation. Austenite - (1) A solid solution of one or more elements in face-centered cubic iron. (2) Phase in certain steels, characterized as a solid solution, usually of carbon or iron carbide. Such steels are known as austenitic. Austenite is stable only above 1333 (degrees) F. in a plain carbon steel, but the presence of certain alloying elements, such as nickel and manganese, stabilizes the austenitic form, even at normal temperatures. Austenitic Steel - Steel, which, because of the presence of alloying elements, such as manganese, nickel, chromium, etc., shows stability of Austenite at normal temperatures. Austenitizing - Forming austenite by heating a ferrous alloy into the transformation range (partial austenitizing) or above the transformation range (complete austenitizing). Autofrettage - Pre-stressing a hollow metal cylinder by the use of momentary internal pressure exceeding the yield strength.


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Autoradiograph - A radiograph recorded photographically by radiation spontaneously emitted by radioisotopes that are produced in, or added to, the material. This technique identifies the locations of the radioisotopes. Bainite - A eutectoid transformation product of ferrite and a fine dispersion of carbide, generally formed at temperatures below 840 to 930 F (450 to 500 C): upper bainite is an aggregate containing parallel lath-shape units of ferrite, produces the so-called feathery appearance in optical microscopy, and is formed at temperatures above about 660 F (350 C) ; lower bainite consists of individual plate-shape units and is formed at temperatures below about 660 F (350 C). Also, a slender, needle-like (acicular) microstructure appearing in spring steel strip characterized by toughness and greater ductility than tempered Martensite. Bainite is a decomposition product of Austenite best developed at interrupted holding temperatures below those forming fine pearlite and above those giving Martensite. Balanced Steel - Steels in which the deoxidization is controlled to produce an intermediate structure between a rimmed and killed steel. Sometimes referred to as semikilled steels, they possess uniform properties throughout the ingot and amongst their applications are boiler-plate and structural sections. Bamboo Grain Structure - A structure in wire or sheet in which the boundaries of the grains tend to be aligned normal to the long axis and to extend completely through the thickness. Band Saw Steel (Wood) - A hardened tempered bright polished high carbon cold rolled spring steel strip produced especially for use in the manufacture of band saws for sawing wood, non ferrous metals, and plastics. Usually carries some nickel and with a Rockwell value of approximately C40/45. Banded - The 1" or 1-1/4" strapping that is pulled tight around the body of the coil to keep the wraps tight is still on the coil; not broken Banded Structure - Appearance of a metal showing parallel bands in the direction of rolling or working. Banding - Inhomogeneous distribution of alloying elements or phases aligned in filaments or plates parallel to the direction of working. Bark - Surface of metal, under the oxide-scale layer, resulting from heating in an oxidizing environment. In the case of steel, such bark always suffers from decarburization. Base Box - See Tin Plate Base Box. Base Metal - A metal that oxidizes when heated in air, e.g. lead, copper, tin, zinc, as opposed to noble metals such as gold and platinum. Basic Open Hearth - (See Open Hearth Process.) Basic Oxygen Process - A steel making process wherein oxygen of the highest purity is blown onto the surface of a bath of molten iron contained in a basic lined and ladle shaped vessel. The melting cycle duration is extremely short with quality comparable to Open Hearth Steel. Basic Process - A steel making process either Bessemer, open hearth or electric, in which the furnace is lined with a basic refractory. A slag, rich in lime, being formed and phosphorus removed. BASIC STEEL-(See Basic Process.) 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.


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Bath Annealing - Is immersion is a liquid bath (such as molten lead or fused salts) held at an assigned temperature-when a lead bath is used, the process is known as lead annealing. Bauxite - The only commercial ore of aluminum, corresponding essentially to the formula Al2O3xH2O. Beading - Raising a ridge on sheet metal. Bearing Load - A compressive load supported by a member, usually a tube or collar, along a line where contact is made with a pin, rivet, axle, or shaft. Bearing Strength - The maximum bearing load at failure divided by the effective bearing area. In a pinned or riveted joint, the affective area is calculated as the product of the diameter of the hole and the thickness of the bearing member. Belly Band - The band (strapping) that goes around the outside diameter of a coil. Bend Radius - The inside radius of a bent section. Bend Test - Various tests which is used to ascertain the toughness and ductility of a metal product, in which the material is bent around its axis and/ or around an outside radius. A complete test might specify such a bend to be both with and against the direction of grain. For testing, samples should be edge filed to remove burrs and any edgewise cracks resulting from slitting or shearing. If a vice is to be employed, then you must line the jaws with some soft metal, to permit a flow of the metal in the piece being tested. Beryllium Copper - An alloy of copper and 2-3% beryllium with optionally fractional percentages of nickel or cobalt. Alloys of this series show remarkable age-hardening properties and an ultimate hardness of about 400 Brinell (Rockwell C43). Because of such hardness and good electrical conductivity, beryllium-copper is used in electrical switches, springs, etc. Bessemer Process - A process for making steel by blowing air through molten pig iron contained in a refractory lined vessel so that the impurities are thus removed by oxidation. A method of producing steel, first introduced in the last century, where air is blown under pressure through molten iron to remove the impurities by oxidation. The development of the process has led to the present day Basic Oxygen Steel-making plants that account for bulk production of commercial quality steels in the UK. Beveling - Refers to pipe; the end preparation for field welding of the joint. Billet - A solid semi-finished round or square product that has been hot worked by forging, rolling, or extrusion. An iron or steel billet has a minimum width or thickness of 1 1/2 in. and the cross-sectional area varies from 2 1/4 to 36 sq. in. For nonferrous metals, it may also be a casting suitable for finished or semi-finished rolling or for extrusion. Binary Alloy - An alloy containing two elements, apart from minor impurities, as brass containing the two elements copper and zinc. Black Annealing - A process of box annealing or pot annealing ferrous alloy sheet, strip or wire after hot working and pickling. Black Oil Tempered Spring Steel Strip (Scale Less Blue) - A flat cold rolled usually .70/.80 medium high carbon steel strip, blue-black in color, which has been quenched in oil and drawn to desired hardness. While it looks and acts much like blue tempered spring steel and carries a Rockwell hardness of C44/47, it has not been polished and is lower in carbon content. Used for less exacting requirements than clock spring steel, such as snaps, lock springs, hold down


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springs, trap springs, etc. It will take a more severe bend before fracture than will clock spring, but it does not have the same degree of spring-back. Black Plate - A lightweight or a thin uncoated steel sheet or strip so called because of its dark oxide coloring prior to pickling. Two different processes manufacture it. (1) Form sheet bar on single stand sheet mills or sheet mills in tandem. This method is now almost obsolete. (2) On modern, high speed continuous tandem cold reduction mills from coiled hot rolled pickled wide strip into ribbon wound coils to finished gage. Sizes range from 12 to 32 in width, and in thicknesses from 55 lbs. to 275 lbs. base box weight. It is used either as is for stampings, or may be enameled or painted or tin or terne coated. Blast Furnace - A vertical shaft type smelting furnace in which an air blast is used, usually hot, for producing pig iron. The furnace is continuous in operation using iron ore, coke, and limestone as raw materials, which are charged at the top while the molten iron and slag are collected at the bottom and are tapped out at intervals. Blister - A defect in metal, on or near the surface, resulting from the expansion of gas in a subsurface zone. Very small blisters are called pinheads or pepper blisters. Blister Steel - High-carbon steel produced by carburizing wrought iron. The bar, originally smooth, is covered with small blisters when removed from the cementation (carburizing) furnace. Bloom - (1) Ancient Definition: iron produced in a solid condition directly by the reduction of ore in a primitive furnace. The carbon content is variable but usually low. Also known as bloomery iron. The earliest iron making process, but still used in underdeveloped countries. (2) Modern Definition: a semi-finished hot rolled steel product, rectangular in section, usually produced on a blooming mill but sometimes made by forging. (3) A semi-finished hot rolled product, rectangular in cross section, produced on a blooming mill. For iron and steel, the width is not more than twice the thickness, and the cross-sectional area is usually not less than 36 sq. in. Forging sometimes makes iron and steel blooms. Bloomery - A primitive furnace used for direct reduction of ore to iron. Blooming-Mill - A mill used to reduce ingots to blooms, billets slabs, sheet-bar etc. Blowhole - A cavity which was produced during the solidification of metal by evolved gas, which in failing to escape is held in pockets. 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. A process of softening ferrous alloys in the form of hot rolled sheet, by heating in the open furnace to a temperature within the transformation range and then cooling in air. The formation of bluish oxide on the surface is incidental. Blue Brittleness - Reduced ductility occurring as a result of strain aging, when certain ferrous alloys are worked between 300 and 700 (degrees) F. This phenomenon may be observed at the working temperature or subsequently at lower temperatures. Brittleness exhibited by some steels after being heated to some temperature within the range of 300 (degrees) to 650 (degrees) F, and more especially if the steel is worked at the elevated temperature. Killed steels are virtually free of this kind of brittleness. 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,


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or finished parts, It is used also to denote the heating of springs after fabrication in order to improve their properties. Body-Centered - Having the equivalent lattice points at the corners of the unit cell, and at its center; sometimes called centered, or space-centered. Bonderizing - The coating of steel with a film composed largely of zinc phosphate in order to develop a better bonding surface for paint or lacquer. Boron B Atomic Number: 5 Atomic Weight: 10.811 Melting Point: 2348 K (2075C or 3767F) Boiling Point: 4273 K (4000C or 7232F) Density: 2.37 grams per cubic centimeter Phase at Room Temperature: Solid It is gray in color, ignites at about 1112 (degrees) F. and burns with a brilliant green flame, but its melting point in a non-oxidizing atmosphere is about 4000 (degrees) F. Boron is used in steel in minute quantities for one purpose only- to increase the hardenability as in case hardening and to increase strength and hardness penetration. It is usually added between .0005-.003% to significantly increase the hardenability, especially for low carbon alloys. It does not affect the strength of ferrite, therefore not sacrificing ductility, formability or machinability in the annealed state. Bottle Top Mold - Ingot mold, with the top constricted; used in the manufacture of capped steel, the metal in the constriction being covered with a cap fitting into the bottle-neck, which stops rimming action by trapping escaping gases. 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. Brake - A piece of equipment used for bending sheet; also called a bar folder. If operated manually, it is called a hand brake; if power driven, it is called a press brake. Brale - A diamond penetrator, conical in shape, used with a Rockwell hardness tester for hard metals. Brass - This is one of the most widely used of the copper-zinc alloys; it is malleable and ductile; has excellent cold-working; poor hot working and poor machining properties; develops high tensile strength with cold-working. Temper is imparted by cold rolling and classified in hardness by the number of B&S Gages of rolling (reduction in thickness) from the previous annealing gage. Rated excellent for soft soldering; good for silver alloy brazing or oxyacetylene welding and fair for resistance or carbon arc welding. Used for drawn cartridges, tubes, eyelet machine items, snap fasteners, etc. Brass (Yellow) - Strip. 65% copper and 35% zinc. Known as 'High Brass' or 'Two to One Brass'. A copper-zinc alloy yellow in color. Formerly widely used but now largely supplanted by Cartridge Brass. Brasses - Copper base alloys in which zinc is the principal alloying element. Brass is harder and mechanically stronger than either of its alloying elements copper or zinc. It is formable


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and ductile; develops high tensile strength with cold-working and is not heat treatable. Braze Welding - A family of welding procedures where metals are joined by filler metal that has a melting temperature below the solidus of the parent metal, but above 840 (450 C). Brazing - Joining metals by fusion of nonferrous alloys that have melting points above 800 F (425C), but lower than those of the metals being joined. May be accomplished by a torch. Filler metal is ordinarily in rod form in torch brazing; whereas in furnace and dip brazing the work material is first assembled and the filler metal may then be applied as wire, washers, clips, bands, or may be bonded, as in brazing sheet. Break Test (for tempered steel) - A method of testing hardened and tempered high carbon spring steel strip wherein the specimen is held and bent across the grain in a vice-like calibrated testing machine. Pressure is applied until the metal fractures at which point a reading is taken and compared with a standard chart of brake limitations for various thickness ranges. Bridling - The cold working of dead soft annealed strip metal immediately prior to a forming, bending, or drawing operation. A process designed to prevent the formulation of Luder's lines. Caution-Bridled metal should be used promptly and not permitted to (of itself) return to its pre-bridled condition. Bright Annealed Wire - Steel wire bright drawn and annealed in controlled non-oxidizing atmosphere so that surface oxidation is reduced to a minimum and the surface remains relatively bright. Bright Annealing - The process of annealing in a protective atmosphere so as to prevent discoloration of the bright surface desired. Bright Basic Wire - Bright steel wire, slightly softer than Bright Bessemer Wire. Used for round head wood screws, bolts and rivets, electric welded chain, etc. Bright Bessemer Wire - Stiff bright wire of hard temper. Normally wire is drawn down to size without annealing. Bright Dip - An acid solution into which pieces are dipped in order to obtain a clean, bright surface. Bright Drawing - The process of drawing hot rolled steel through a die to impart close dimensional tolerances, a bright, scale free surface, and improved mechanical properties. The product is termed bright steel. Brinell Hardness Test - A common standard method of measuring the hardness of materials. The smooth surface of the metal is subjected to indentation by a hardened steel ball under pressure. A microscope then measures the diameter of the indentation in the material surface, and the hardness value is read from a chart or determined by a prescribed formula. Brittle Fracture - Fracture preceded by little or negligible plastic deformation. Brittleness - The tendency of a metal or material to fracture without undergoing appreciable plastic deformation. Broaching - Multiple shaving, accomplished by pushing a tool with stepped cutting edges along the piece, particularly through holes. Bronze - Primarily an alloy of copper and tin, but additionally, the name is used when


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referring to other alloys not containing tin, for example, aluminum bronze, manganese bronze, and beryllium bronze. Brown & Sharp Gages (B&S) - A standard series of sizes referred to by numbers, in which the diameter of wire or thickness of sheet metal is generally produced and which is used in the manufacture of brass, bronze, copper, copper-base alloys and aluminum. These gage numbers have a definite relationship to each other. In this system, the decimal thickness is reduced by 50% every six gage numbers- while temper is expressed by the number of B&S gage numbers as cold reduced in thickness from previous annealing. For each B&S gage number in thickness reduction, where is assigned a hardness value of 1/4 hard. Buckle - Bulges and/ or hollows occurring along the length of the metal with the edges remaining otherwise flat. Alternate bulges or hollows recurring along the length of the product with the edges remaining relatively flat. Heating a metal beyond the temperature limits allowable for the desired heat treatment, or beyond the point where serious oxidation or other detrimental action begins. Buffer - A substance added to aqueous solutions to maintain a constant hydrogen-ion concentration, even in the presence of acids or alkalis. Burning - (1) Permanently damaging a metal or alloy by heating to cause either incipient melting or intergranular oxidation. (2) In grinding getting the work hot enough to cause discoloration or to change the microstructure by tempering or hardening. (3) Heating a metal beyond the temperature limits allowable for the desired heat treatment, or beyond the point where serious oxidation or other detrimental action begins. Burnishing - Smoothing surfaces through friction between the material and material such as hardened metal media. Burnt - A definition applying to material which has been permanently damaged by overheating. Burr - Roughness left by a cutting operation such as slitting, shearing, blanking , etc. Bruise - A raised area in the steel caused by an object going between the work rolls and bruising them. Butcher Saw Steel - A hardened, tempered, and polished high carbon spring steel strip material (carbon content is generally higher than that of a material used for wood band saw applications) with a Rockwell value of roughly C47/49. Butt Welding - (1) Joining two edges or ends by placing one against the other and welding them. (2) The type of welding that fuses the head end of one coil to the tail end of another, using heat, without overlapping the strip. Cake - A copper ingot rectangular in cross section intended for rolling. Calcium Ca Atomic Number: 20 Atomic Weight: 40.078 Melting Point: 1115 K (842C or 1548F) Boiling Point: 1757 K (1484C or 2703F) Density: 1.54 grams per cubic centimeter Phase at Room Temperature: Solid


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Is used in certain steels to control the shape, size and distribution of oxide and/or sulfide inclusions. Benefits may include improved ductility, impact strength and machinability. Camber or Bow - (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 cause by the rolling pressure. (3) Edgewise curvature. A lateral departure of a side edge of sheet or strip metal from a straight line. Camera Shutter Steel - Hardened, tempered and bright polished extra flat and extra precision rolled. Carbon content 1.25 - Chromium .15. Canning - A dished distortion in a flat or nearly flat surface, sometimes referred to as oil canning. Capped Steel - Semikilled steel cast in a bottle-top mold and covered with a cap fitting into the neck of the mold. The cap causes to top metal to solidify. Pressure is built up in the sealedin molten metal and results in a surface condition much like that of rimmed steel. Carbide - A compound of carbon with one or more metallic elements. Carbon C Atomic Number: 6 Atomic Weight: 12.0107 Melting Point: 3823 K (3550C or 6422F) Boiling Point: 4098 K (3825C or 6917F) Density: 2.2670 grams per cubic centimeter Phase at Room Temperature: Solid Carbon has three allotropic modifications, all non-metallic. Carbon is present in practically all ferrous alloys, and has tremendous effect on the properties of the resultant metal. Carbon is also an essential component of the cemented carbides. Its metallurgical use, in the form of coke, for reduction of oxides, is very extensive. Is the most important alloying element which is essential for the formation of cementite, pearlite, spheriodite, bainite, and iron-carbon martensite. Compared to steels with similar microstructures, strength, hardness, hardenability, and ductile-to-brittle transition temperature are increased with increasing carbon content up to approximately .60%. Toughness and ductility of pearlitic steels are decreased with increasing carbon content. Carbon Equivalent - Referring to the rating of weld-ability, this is a value that takes into account the equivalent additive effects of carbon and other alloying elements on a particular characteristic of a steel. For rating of weld-ability, a formula commonly used is: CE = C + (Mn/6) + [(Cr + Mo + V)/5] + [(Ni + Cu)/15]. Carbon Free - Metals and alloys which are practically free from carbon. Carbon Potential - A measure of the capacity of an environment containing active carbon to alter or maintain, under prescribed conditions, the carbon concentration in a steel. Carbon Range - In steel specifications, the carbon range is the difference between the minimum and maximum amount of carbon acceptable. Carbon Restoration - Replacing the carbon lost in the surface layer during previous processing by carburizing this layer to substantially the original carbon level.


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Carbon Steel - (1) Common or ordinary steel as contrasted with special or alloy steels, which contain other alloying metals in addition to the usual constituents of steel in their common percentages. (2) Steel containing carbon up to about 2% and only residual quantities of other elements except those added for deoxidization, with silicon usually limited to 0.60% and manganese to about 1.65%. Also termed plain carbon steel, ordinary steel, and straight carbon steel. Carbonitriding - Introducing carbon and nitrogen into a solid ferrous alloy by holding above Ac1 in an atmosphere that contains suitable gases such as hydrocarbons, carbon monocide, and ammonia. The carbonitrided alloy is usually quench hardened. A case hardening process in which a suitable ferrous material is heated above the lower transformation temperature in a gaseous atmosphere having a composition that results in simultaneous absorption of carbon and nitrogen by the surface and, by diffusion, creates a concentration gradient. The process is completed by cooling at a rate that produces the desired properties in the work piece. Carburizing (Cementation) - A process in which an austenitized ferrous material is brought into contact with a carbonaceous atmosphere having sufficient carbon potential to cause absorption of carbon at the surface and, by diffusion, create a concentration gradient. Introducing carbon into a solid ferrous alloy by holding above Ac1 in contact with a suitable carbonaceous material, which may be a solid, liquid, or gas. The carburized alloy is usually quench hardened. Adding carbon to the surface of iron-base alloys by absorption through heating the metal at a temperature below its melting point in contact with carbonaceous solids, liquids or gases. The oldest method of case hardening. Cartridge Brass - 70% copper 30% zinc. This is one of the most widely used of the copperzinc alloys; it is formable and ductile and possesses excellent cold-working, poor hot working and poor machining properties. Rated excellent for soft-soldering; good for silver alloy brazing or oxyacetylene welding and fair for resistance of carbon arc welding. The alloy develops high tensile strength with cold-working. Temper is obtained by cold rolling. Case - In a ferrous alloy, the outer portion that has been made harder than the inner portion, or core. Case Hardening - Carburizing and subsequently hardening by suitable heat-treatment, all or part of the surface portions of a piece of iron-base alloy. Hardening a ferrous alloy so that the outer portion, or case, is made substantially harder than the inner portion, or core. Typical processes used for case hardening are carburizing, cyaniding, carbonitriding, nitriding, induction hardening, and flame hardening. A generic term covering several processes applicable to steel that change the chemical composition of the surface layer by absorption of carbon or nitrogen, or a mixture of the two, and, by diffusion, create a concentration gradient. Cast - (1) A term indicating in the annealed state as Cast Spring Steel Wire. (2) In reference to Bright or Polished Strip Steel or Wire, the word cast implies discoloration as a shadow. (3) A term implying a lack of straightness as in a coil set. Cast Iron - Iron containing more carbon than the solubility limit in austenite (about 2%). Cast Steel - Steel in the form of castings, usually containing less than 2% carbon. Any object made by pouring molten steel into molds.


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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 to produce an object of desired shape. Cavitation - The formation and instantaneous collapse of innumerable tiny voids or cavities within a liquid subjected to rapid and intense pressure changes. 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 - Wearing away of metal through the formation and collapse of cavities in a liquid. Cementation - (1) Introduction of one or more elements into the outer layer of a metal object by means of diffusion at high temperature. (2) An obsolete process used to convert wrought iron to blister steel by carburizing. Wrought iron bars were packed in sealed chests with charcoal and heated at about 2000 F (1100 C) for 6 to 8 days. Cementation was the predominant method of manufacturing steels particularly high-carbon tool steels, prior to the introduction of the Bessemer and open-hearth methods. Cementite - A compound of iron and carbon known as Iron carbide, which has the approximate chemical formula Fe3C containing 6.69% of carbon. Hard and brittle, it is the hard constituent of cast iron, and the normal form in which carbon is present in steel. It is magnetizable, but not as readily as ferrite. 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. It has limited substitution solubility for the carbide-forming elements, notably manganese. 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. Cerium Ce Atomic Number: 58 Atomic Weight: 140.116 Melting Point: 1071 K (798C or 1468F) Boiling Point: 3697 K (3424C or 6195F) Density: 8.16 grams per cubic centimeter Phase at Room Temperature: Solid Cerium is the most abundant of the rare earth elements and makes up about 0.0046% of the earth's crust. Today, cerium is primarily obtained through an ion exchange process from monazite sand (Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements. Pure cerium will ignite if it is scratched with a sharp object, but can be safely used if combined with other materials. Cerium is one of the rare earth elements used to make carbon arc lights which are used in the motion picture industry for studio lighting and projector lights. Cerium is also a component of Misch metal, a material that is used to make flints for lighters. Cerium is also used as a catalyst to refine petroleum and as an alloying agent to make special metals. Cermet - A powder metallurgy product consisting of ceramic particles bonded with a metal. Chafery - A charcoal-fired furnace used in early iron making processes to reheat a bloom of wrought iron for forging to consolidate the iron and expel entrapped slag. Chamfer - (1) A beveled surface to eliminate an otherwise sharp corner. (2) A relieved


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angular cutting edge at a tooth corner. Charcoal Tin Plate - Tin Plate with a relatively heavy coating of tin (higher than the Coke Tin Plate grades). Charpy 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. Chatter Marks - Parallel indentations or marks appearing at right angles to edge of strip forming a pattern at close and regular intervals, caused by roll vibrations. Chemical Milling - Removing metal stock by controlled selective chemical etching. Chemical Polishing - Improving the specular reflectivity of a metal surface by chemical treatment. Chemical Treatment - A substance (chromic acid) that is applied to hot dip galvanize sheet to prevent the formation of white rust during shipping and storage. Chemistry (of slab) - The chemical composition of the steel that in part determines the physical and mechanical properties of the product. Chipping - A method for removing seams and other surface defects with chisel or gouge so that such defects will not be worked into the finished product. Chipping is often employed also to remove metal that is excessive but not defective. Removal of defects by gas cutting is known as deseaming or scarfing. Chromadizing (Chromodizing, Chromatizing) - Forming an acid surface to improve paint adhesion on aluminum or aluminum alloys, mainly aircraft skins, by treatment with a solution of chromic acid. Chromium Cr Atomic Number: 24 Atomic Weight: 51.9961 Melting Point: 2180 K (1907C or 3465F) Boiling Point: 2944 K (2671C or 4840F) Density: 7.15 grams per cubic centimeter Phase at Room Temperature: Solid It is of bright silvery color, relatively hard. It is strongly resistant to atmospheric and other oxidation. It is of great value in the manufacture of Stainless Steel as an iron-base alloy. Chromium plating has also become a large outlet for the metal. Its principally functions as an alloy in steel making; (1) increases resistance to corrosion and oxidation (2) increases hardenability (3) adds some strength at high temperatures (4) resists abrasion and wear (with high carbon). Straight chromium steels are susceptible to temper embrittlement and can be brittle. Chromium-Nickel Steel - Steel usually made by the electric furnace process in which chromium and nickel participate as alloying elements. The stainless steel of 18% chromium and 8% nickel are the better known of the chromium-nickel types. 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.


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Cigarette Knife Steel - Hardened, tempered and bright polished, 1.25 Carbon contentChromium .15. Accurate flatness necessary and a high hardness with Rockwell C 51 to 53. Usual sizes are 4 3/4 wide and 6 wide x .004 to .010. 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, heavy chemical deposition or heavy electroplating. Cladding - A process for covering one metal with another. Usually the surfaces of fairly thick slabs of two metals are brought carefully into contact and are then subjected to co-rolling so that a clad composition results. In some instances a thick electroplate may be deposited before rolling. Cleavage - Fracture of a crystal by crack propagation across a crystallographic plane of low index. Cleavage Fracture - Fracture of a grain, or most of the grains, in a polycrystalline metal by cleavage, resulting in bright reflecting facets. Cleavage Plane - A characteristic crystallographic plane or set of planes in a crystal on which cleavage fracture occurs easily. Cluster Mill - A rolling mill where each of the two working rolls of small diameter is supported by two or more back-up rolls. Cobalt Co Atomic Number: 27 Atomic Weight: 58.933200 Melting Point: 1768 K (1495C or 2723F) Boiling Point: 3200 K (2927C or 5301F) Density: 8.86 grams per cubic centimeter Phase at Room Temperature: Solid A gray magnetic metal, of medium hardness; it resists corrosion like nickel, which it resembles closely; melting point 2696 (degrees) F.; specific gravity 8.9. It is used as the matrix metal in most cemented carbides and is occasionally electroplated instead of nickel, the sulfate being used as electrolyte. Its principal function as an alloy in tool steel; it contributes to red hardness by hardening ferrite. Coefficient of Expansion - The ratio of change in length, area, or volume per degree to the corresponding value at a standard temperature. Cogging - An intermediate rolling process when a hot ingot is reduced to a bloom or slab in a cogging mill. Coil Breaks - Creases or ridges across a metal sheet transverse to the direction of coiling, occasionally occurring when the metal has been coiled hot and uncoiled cold. Coil Set or Longitudinal Curl - A lengthwise curve or set found in coiled strip metals following its coil pattern. A departure from longitudinal flatness. Can be removed by roller or stretcher leveling from metals in the softer temper ranges. Coil Weld - A joint between two lengths of metal within a coil - not always visible in the cold reduced product.


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Coils - Coiled flat sheet or strip metal- usually in one continuous piece or length. Coining - A process of impressing images or characters of the die and punch onto a plane metal surface. Coke Plate (Hot Dipped Tin Plate) - Standard tin plate, with the lightest commercial tin coat, used for food containers, oil canning, etc. A higher grade is the best cokes, with special cokes representing the best of the coke tin variety. For high qualities and heavier coatings. Cold Drawing - The process of reducing the cross sectional area of wire, bar or tube by drawing the material through a die without any pre-heating. Cold drawing is used for the production of bright steel bar in round square, hexagonal and flat section. The process changes the mechanical properties of the steel and the finished product is accurate to size, free from scale with a bright surface finish. Cold Reduced Strip - Metal strip, produced from hot-rolled strip, by rolling on a cold reduction mill. Cold Reduction - (1) Reduction of metal size, usually by rolling or drawing particularly thickness, while the metal is maintained at room temperature or below the recrystallization temperature of the metal. (2) Reduction of strip thickness through the use of force rather than heat. Cold Rolled Finish - Finish obtained by cold rolling plain pickled sheet or strip with a lubricant resulting in a relatively smooth appearance. Cold Rolling - Rolling metal at a temperature below the softening point of the metal to create strain hardening (work-hardening). Same as cold reduction, except that the working method is limited to rolling. Cold rolling changes the mechanical properties of strip and produces certain useful combinations of hardness, strength, stiffness, ductility and other characteristics known as tempers, which see. 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 portion of the surface of a forging that is separated, in part, from the main body of metal by oxide. (3) A condition of brittleness existing in some metals at temperatures below the recrystallization temperature. Cold Treatment - Exposing steel to suitable subzero temperatures (-85 C, or -120 F) 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 Work - Permanent strain produced by an external force in a metal below its recrystallization temperature. Cold Working - Plastic deformation, such as rolling, hammering, drawing, etc., at a temperature sufficiently low to create strain-hardening (work-hardening). Commonly, the term refers to such deformation at normal temperatures. Columbium - See Niobium Nb Columnar Structure - A coarse structure of parallel columns of grains, having the long axis perpendicular to the casting surface. Commercial Bronze - A copper-zinc alloy (brass) containing 90% copper and 10% zinc; used for screws, wire, hardware, etc. Although termed commercial-bronze it contains no tin. It is


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somewhat stronger than copper and has equal or better ductility. Commercial Quality Steel Sheet - Normally to a ladle analysis of carbon limit at 0.15 max. A Standard Quality Carbon Steel Sheet. Compressive Strength - The maximum compressive stress that a material is capable of developing, based on original area of cross section. In the case of a material which fails in compression by a shattering fracture, the compressive strength has a very definite value. In the case of materials which do not fail in compression by a shattering fracture, the value obtained for compressive strength is an arbitrary value depending upon the degree of distortion that is regarded as indicating complete failure of the material. Constitute - A phase, or combination of phases, that occurs in a characteristic configuration in a microstructure. Constitutional Diagram - A graphical representation of the temperature and composition limits of phase fields in an alloy system as they actually exist under specific conditions of heating and cooling (synonymous with phase diagram). A constitutional diagram may be, or may approximate, and equilibrium diagram, or may represent metastable conditions or phases. Compare equilibrium diagram. Continuous Casting - (1) A method of producing blooms, billets and slabs in long lengths using water cooled moulds. The castings are continuously withdrawn through the bottom of the caster whilst the teeming of the metal is proceeding. The need for primary and intermediate mills and the storage and use of large numbers of ingot moulds is eliminated. The continuous casting process is also used in the production of cast iron, aluminum and copper alloys. (2) A casting technique in which the ingot, billet, tube, or other shape is continuously solidified while it is being poured, and the length is not determined by mold dimensions. Contact Corrosion - When two dissimilar metals are in contact without a protective barrier between them and they are in the presence of liquid, an electrolytic cell is created. The degree of corrosion is dependent on the area in contact and the electro-potential voltage of the metals concerned. The less noble of the metals is liable to be attacked, i.e. zinc will act as a protector of steel in sea water whereas copper or brass will attack the steel in the same environment. Continuous Furnace - Furnace, in which the material being heated moves steadily through the furnace. Continuous Phase - In an alloy or portion of an alloy containing more than one phase, the phase that forms the background or matrix in which the other phase or phases are present as isolated volumes. Continuous Pickling - Passing sheet or strip metal continuously through a series of pickling and washing tanks. Continuous Strip Mill - A series of synchronized rolling mill stands in which coiled flat rolled metal entering the first pass (or stand) moves in a straight line and is continuously reduced in thickness (not width) at each subsequent pass. The finished strip is recoiled upon leaving the final or finishing pass. Controlled Atmosphere Furnaces - A furnace used for bright annealing into which specially prepared gases are introduced for the purpose of maintaining a neutral atmosphere so that no oxidizing reaction between metal and atmosphere takes place. Controlled Rolling - A hot rolling process in which the temperature of the steel is closely


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controlled, particularly during the final rolling passes, to produce a fine-grain microstructure. Converter - A furnace in which air is blown through the molten bath of crude metal or matte for the purpose of oxidizing impurities. Cooling Stresses - Stresses developed by uneven contraction or external constraint of metal during cooling; also those stresses resulting from localized plastic deformation during cooling, and retained. Copper Cu Atomic Number: 29 Atomic Weight: 63.546 Melting Point: 1357.77 K (1084.62C or 1984.32F) Boiling Point: 2835 K (2562C or 4644F) Density: 8.933 grams per cubic centimeter Phase at Room Temperature: Solid A characteristically reddish metal of bright luster, highly malleable and ductile and having high electrical and heat conductivity; Universally and extensively used in the arts in brasses, bronzes. Universally used in the pure state as sheet, tube, rod and wire and also as alloyed by other elements and an alloy with other metals. It is used in certain steels to improve resistance to atmospheric corrosion. Core - In the case of steel this refers to a component that has been case-hardened where the centre is softer than the hard surface layer or case. It can also be applied to the central part of a rolled rimming steel. Coring - A variation of composition between the center and surface of a unit of structure (such as a dendrite, a grain or a carbide particle) resulting from non-equilibrium growth over a range of temperature. Corrosion - (1) Gradual chemical or electrochemical attack on a metal by atmosphere, moisture or other agents. (2) Deterioration of a metal by chemical or electrochemical reaction with its environment. Corrosion Embrittlement - The embrittlement caused in certain alloys by exposure to a corrosive environment. Such material is usually susceptible to the intergranular type of corrosion attack. The severe loss of ductility of a metal resulting from corrosive attack, usually intergranular and often not visually apparent. Corrosion Fatigue - Effect of the application of repeated or fluctuating stresses in a corrosive environment characterized by shorter life than would be encountered as a result of either their repeated or fluctuating stresses alone or the corrosive environment alone. Corrugated - As a defect. Alternate ridges and furrows. A series of deep short waves. Coupon - A piece of metal from which a test specimen is to be prepared - often an extra piece (as on a casting or forging) or a separate piece made for test purposes (such as a test weldment). Covered Electrode - A filler-metal electrode, used in arc welding, consisting of a metal core wire with a relatively thick covering which provides protection for the molten metal form the atmosphere, improves the properties of the weld metal and stabilizes the arc. The covering is usually mineral or metal powders mixed with cellulose or other binder.


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Creep - The flow or plastic deformation of metals held for long periods of time at stresses lower than the normal yield strength. The effect is particularly important if the temperature of stressing is above the recrystallization temperature of the metal. 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 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 creep react at constant temperature. Crevice Erosion - A type of concentration-cell corrosion; corrosion of a metal that is caused by the concentration 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 Cooling Rate - The minimum rate of continuous cooling just sufficient to prevent undesired transformations. For steel, the slowest rate at which it can be cooled form above the upper critical temperature to prevent the decomposition of austenite at any temperature above the Ms. The limiting rate at which austenite must be cooled to ensure that a particular type of transformation product is formed. Critical Point(s) - (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 systems are in equilibrium. (3) Temperatures at which internal changes or transformations take place within a metal either on a rising or falling temperature. Critical Range - A temperature range in which an internal change takes place within a metal. Also termed transformation range. Critical Strain - That strain which results in the formation of very large grains during recrystallization. Critical Temperature - Synonymous with critical point if pressure is constant. Crop - The defective ends of a rolled or forged product which are cut off and discarded. Cutting off ends of billets ingots or slabs containing pipe or other defects. Cropped Head/Tail - Squaring of the strip by use of mechanical shear. Cross Rolling - (1) The rolling of sheet so that the direction of rolling is changed about 90 (degrees) from the direction of the previous rolling. (2) A (hot) rolling process in which rolling reduction is carried out in a direction perpendicular to, as well as a direction parallel to, the length of the original slab. Rolling at an angle to the long dimension of the metal; usually done to increase width. Crossbow - Deviation from flat across the strip width.


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Cross Direction (in rolled or drawn metal) - The direction parallel to the axes of the rolls during rolling. The direction at right angles to the direction of rolling or drawing. Crown or Heavy Center - A contour on a sheet or roll where the thickness or diameter increases from edge to center. The difference in strip thickness from center to edge. Increased thickness in the center of metal sheet or strip as compared with thickness at the edge. Crucible - A ceramic pot or receptacle made of graphite and clay, or clay or other refractory material, and used in the melting of metal. The term is sometimes applied to pots made of cast iron, cast steel or wrought steel. Crucible Steel - High-carbon steel produced by melting blister steel in a covered crucible. Crucible steel was developed by Benjamin Huntsman in about 1750 and remained in use until the late 1940's. Cryogenic Applications - Sub-zero temperature applications. Crystal - (1) A physically homogeneous solid in which the atoms. ions or molecules are arranged in a three-dimensional repetitive pattern. (2) A coherent piece of matter, all parts of which have the same anisotropic arrangement of atom; in metals, usually synonymous with grain and crystallite. Crystalline - Composed of crystals. Crystalline Fracture - A fracture of a polycrystalline metal characterized by a grainy appearance. Compare fibrous fracture. Crystallization - The formation of crystals by the atoms assuming definite positions in a crystal lattice. This is what happens when a liquid metal solidifies. (Fatigue, the failure of metals under repeated stresses, is sometimes falsely attributed to crystallization.) Cube-Centered - Metallography- (concerning space lattices) - Body-centered cubic. Refers to crystal structure. Cup Fracture (Cup-and-Cone Fracture) - Fracture, frequently seen in tensile test pieces of a ductile material, in which the surface of failure on one portion shows a central flat area of failure in tension, with an exterior extended rim of failure in shear. A type of fracture in a tensile test specimen which looks like a cup having the exterior portion extended with the interior slightly depressed. Cupping - The fracture of severely worked rods or wire where one end has the appearance of a cup and the other that of a cone. Cutting Speed - The linear or peripheral speed of relative motion between the tool and work piece in the principal direction of cutting. Cyaniding - Surface hardening of an iron-base alloy article or portion of it by heating at a suitable temperature in contact with a cyanide salt, followed by quenching. Introducing carbon and nitrogen into a solid ferrous alloy by holding above Ac1 in contact with molten cyanide of suitable composition. The cyanided alloy is usually quench hardened. Cyanide Hardening - A process of introducing carbon and nitrogen into the surface of steel by heating it to a suitable temperature in a molten bath of sodium cyanide, or a mixture of sodium and potassium cyanide, diluted with sodium carbonate and quenching in oil or water. This process is used where a thin case and high hardness are required.


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DC (Direct Chill) Casting - A continuous method of making ingots or billets for sheet 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 semi continuous casting. Dead Flat - Perfectly flat. As pertaining to sheet, strip or plate. Refer to Stretcher Leveling. Dead Soft Annealing - Heating metal to above the critical range and appropriately cooling to develop the greatest possible commercial softness or ductility. Dead Soft Steel - Steel, normally made in the basic open-hearth furnace or by the basic oxygen process with carbon less than 0.10% and manganese in the 0.20-0.50% range, completely annealed. Dead Soft Temper - Condition of maximum softness commercially attainable in wire, strip, or sheet metal in the annealed state. Deburring - A method whereby the raw slit edge of metal is removed by rolling or filing. Decarburization - Removal of carbon from the outer surface of iron or steel, usually by heating in an oxidizing or reducing atmosphere. Water vapor, oxygen and carbon dioxide are strong decarburizers. Reheating with adhering scale is also strongly decarburizing in action. Loss of carbon from the surface of a ferrous alloy as a result of heating in a medium that reacts with carbon. Decoration (of dislocations) - Segregation of solute atoms to the line of a dislocation in a crystal. In ferrite, the dislocations may be decorated with carbon or nitrogen atoms. Deep Drawing - The process of cold working or drawing sheet or strip metal blanks by means of dies on a press into shapes which are usually more or less cup-like in character involving considerable plastic deformation of the metal. Deep-drawing quality sheet or strip steel, ordered or sold on the basis of suitability for deep-drawing Deformative Bands - Generally, bands in which deformation has been concentrated unhomogeneously. Degassing Process (In steel making) - Removing gases from the molten metal by means of a vacuum process in combination with mechanical action. Degenerate Structure - Usually refers to pearlite that does not have an ideally lamellar structure. The degree of degeneracy may vary from slight perturbations in the lamellar arrangement to structures that are not recognizably lamellar. Degreasing - Removal of grease, oil or other lubricant-type materials by immersion in an effective solvent. Usually are used primarily alkaline cleaners, although an organic solvents are useful. Delta Iron - Allotropic modification of iron, stable above 2552 (degrees) F. to melting point. It is of body-centered cubic crystal structure.


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Dendrite - A crystal that has grown in treelike branching mode. A crystal that has a tree-like branching pattern, being most evident in cast metals slowly cooled through the solidification range. Dendritic Segregation - Inhomogeneous distribution of alloying elements through the arms of dendrites. Deoxidation - (1) Removal of oxygen from molten metals by use of suitable chemical agents. (2) Sometimes refers to removal of undesirable elements other than oxygen by the introduction of elements or compounds that readily react with them. In steel sheet, strip, and wire technology, the term refers to heat treatment in a reducing atmosphere, to lessen the amount of scale. Descaling - It is necessary to remove the scale from hot rolled bars or coil before bright drawing. This is normally carried out by shot blasting or pickling in acid. Other methods of descaling steel products include sand blasting, flame descaling and tumbling. Deseaming - A process of burning out defective areas on the surface of ingots, blooms or billets. The condition of the surface is such that it can then be rolled or forged into a satisfactory product. DI (Ideal Diameter) - The diameter of a round steel bar that will harden at the center to a given percent of martensite when subjected to an ideal quench (i.e., Grossman quench severity H=infinity) Diamond Pyramid Hardness Test - This test, more commonly known as the Vickers test, finds greater use in the laboratory than the workshop. It employs a pyramid shaped diamond with an included angle of 136o which is impressed into the specimen using loads of 5 to 120 kg making a small square impression. This test is used for finished or polished components because the impression can be very small. The diamond pyramid hardness number is obtained from a calculation based on measuring the diagonals of the impressions in the steel. Die - The term die is most commonly used in tooling, i.e. press tools "punch and die" but there are many other types of die, e.g. thread cutting dies, forming dies, forging dies, die-casting dies, etc. The term when applied to steel often refers to drawing dies through which hot rolled wire and bar are drawn to produce the finish and dimensional accuracy that is required for bright steel. Die Sinking - Forming or machining a depressed pattern in a die. Die-Lines - Lines of markings daused on drawn or extruded products by minor imperfections in the surface of the die. 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. Dilatometer - An instrument for measuring the expansion or contraction of a solid metal resulting from heating, cooling, polymorphic changes, etc. Discoloration - A change in the visual appearance of the material caused by formation of oxides when exposed to contaminating atmosphere, always at elevated temperatures. Dish - A concave surface departing from a straight line edge to edge. Indicates transverse or across the width.


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Dislocation - A linear defect in the structure of a crystal. Doctor Blade Steel Strip - A hardened and tempered spring steel strip, usually blued, produced from approximately .85 carbon cold rolled spring steel strip specially selected for straightness and good edges. Sometimes hand straightened or straightened by grinding and cur to desired lengths. This product is used in the printing trade as a blade to uniformly remove excess ink (dope) from the rolls; hence its name. Dolomite - A natural carbonate of calcium and magnesium generally used as a flux in blast furnaces. Drawing - (1) Forming recessed parts by forcing the plastic flow of metal in dies. (2) Reducing the cross section of wire or tubing by pulling it through a die. (3) A misnomer for tempering. Drawing Back - Reheating after hardening to a temperature below the critical for the purpose of changing the hardness of the steel. Draw Quality - More flexible grade of steel. Dressing of coil - Eliminating any damage or defects from the outer or inner diameter of the coil in preparation for shipping. Drill Rod - A term given to an annealed and polished high carbon tool steel rod usually round and center less ground. The sizes range in round stock from .013 to 1 1/2 diameter. Commercial qualities embrace water and oil hardening grades. A less popular but nevertheless standard grade is a non-deforming quality. Drill Rods are used principally by machinists and tool and die makers for punches, drills, taps, dowel pins, screw machine parts, small tools, etc. Drop Forging - A forging made with a drop hammer. An operation in which a metal shape is formed by forcing hot metal into impressions formed in solid blocks of hardened alloy steel, the forging dies. The dies are made in halves, one attached to the rising and falling block of the drop forge and the other to the stationary anvil. Drop forgings are widely used in the automotive industry for crankshafts, stub-axles, gears, etc. Drop Hammer - A forging hammer than depends on gravity for its force. Dry Rolled Finish - Finish obtained by cold rolling on polished rolls without the use of any coolant or metal lubricant, of material previously plain pickled, giving a burnished appearance. Ductile Crack Propagation - Slow crack propagation that is accompanied by noticeable plastic deformation and requires energy to be supplied from outside the body. 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. The property of metals that enables them to be mechanically deformed when cold, without fracture. In steel, ductility is usually measured by elongation and reduction of area as determined in a tensile test. 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,


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and marine applications. Durability - The ability to accept permanent deformation. Duralumin (obsolete) - The trade name applied to the first aluminum-copper-magnesium type of age-hardenable alloy (17S), which contains nominally 4% Cu, 1/2% Mg. The term is sometimes used to include the class of wrought aluminum-copper-magnesium alloys that harden during aging at room temperature. Dye Penetrant Inspection - A method for detecting surface porosity or cracks in metal. The part to be inspected is cleaned and coated with a dye which penetrates any flaws that may be present. The surface is wiped clean and coated with a white powder. The powder absorbs the dye held in the defects indicating their location. Earing - Wavy projections formed at the open end of a cup or shell in the course of deep drawing because of difference in directional properties. Also termed scallop. The formation of scallops (ears) around the top edge of a drawn part caused by differences in the directional properties of the sheet metal used. Eddy-Current Testing - 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 for subsequent analysis by suitable instrumentation and techniques. Edge Filing - A method whereby the raw or slit edges of strip metal are passed or drawn one or more times against a series of files, mounted at various angles. This method may be used for deburring only or filing to a specific contour including a completely rounded edge. Edge Strain or Edge Breaks - Creases extending in from the edge of the temper rolled sheet. Edges - Many types of edges can be produced in the manufacture of flat rolled metal products. Over the years the following types of edges have become recognized as standard in their respective fields. . Copper Base Alloys- Slit, Slit and Edge Rolled, Sheared, Sawed, Machined or Drawn . Sheet Steels or Aluminum Sheet- Mill Edge, Slit Edge or Sheared Edge. . Strip Steels and Stainless Strip . No. 1 Edge A- Smooth, uniform, round or square edge, either slit or filed or slit and edge rolled as specified, width tolerance +/- .005. . No. 2 Edge- A natural sound mill edge carried through from the hot rolled band. Has not been slit, filed, or edge rolled. Tolerances not closer than hot-rolled strip limits. . No. 3 Edge - Square, produced by slitting only. Not filed. Width tolerances close. . No. 4 Edge - A round edge produced by edge rolling either from a natural mill edge or from slit edge strip. Not as perfect as No. 1 edge. Width tolerances liberal. . No. 5 Edge - An approximately square edge produced by slitting and filing or slitting and rolling to remove burr. . No. 6 Edge - A square edge produced by square edge rolling, generally from square edge hot-rolled occasionally from slit strip. Width tolerances and finish not as exacting as No. 1 edge. Edging - The dressing of metal strip edges by rolling, filing or drawing. Egg-Shaped Coils - Coil that is sagging at the center. Elastic Limit - The maximum stress to which a material may be subjected without any permanent strain remaining upon complete release of stress. Maximum stress that a material will stand before permanent deformation occurs Elastic Strain - Dimensional changes accompanying stress where the original dimensions are


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restored upon release of the stress. Elasticity - The property which enables a material to return to its original shape and dimension. Electocleaning (Electrolytic Brightening) - An anodic treatment. A cleaning, polishing, or oxidizing treatment in which the specimen or work is made the anode in a suitable electrolyte; an inert metal is used as cathode and a potential is applied. Electric Arc Furnace (EAF) - Steelmaking furnace where scrap is generally 100% 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 Furnace Steel - Steel made in any furnace where heat is generated electrically, almost always by arc. Because of relatively high cost, only tool steels and other high-value steels are made by the electric furnace process. Electrical Steels - Steels which are characterized by their magnetic properties and are intended for the manufacture of electrical circuits. They are supplied in the form of cold rolled sheet or strip, generally less than 2mm thick and up to 1500mm wide. Grain orientated steels have preferential magnetic properties in the direction of rolling and non- grain orientated steels have similar magnetic properties both transversely and in the direction of rolling. Electocleaning - (Electrolytic Brightening) An anodic treatment. A cleaning, polishing, or oxidizing treatment in which the specimen or work is made the anode in a suitable electrolyte; an inert metal is used as cathode and a potential is applied. Electrogalvanized - Zinc plating process whereby the molecules on the positively charged zinc anode attach to the negatively charged sheet steel. The thickness of the zinc coating is readily controlled. By increasing the electric charge or slowing the speed of the steel through the plating area, the coating will thicken. Electro-Galvanizing - Galvanizing by Electro deposition of zinc on steel. Electrolytic Tin Plate - Black Plate that has been Tin plated on both sides with commercially pure tin by electrode position. Electron Beam Microprobe Analyzer - An instrument for selective chemical analysis of a small volume of material. An electron beam bombards the area of interest and x-radiation thereby emitted is analyzed in a spectrometer. Electroplating - The production of a thin coating of one metal on another by elect deposition. It is very extensively used in industry and is continuing to enlarge its useful functions. Various plated metal and combinations thereof are being used for different purposes, to illustrate: 1. Decorative and protection against corrosion; copper, nickel and chromium . 2. Protection against corrosion; cadmium or zinc . 3. Protection against wear; chromium . 4. Build-up of a part or parts undersize; chromium or nickel . 5. Pate for rubber adhesion; brass . 6. Protection against carburization and for brazing operations....copper and nickel The production of a thin coating of one metal on another by electro-deposition. It is very extensively used in industry and is continuing to enlarge its useful functions. Various plated metals and combinations thereof are being used for different purposes. Electropolishing - Improving the specular reflectivity of a metal surface by electrochemical dissolution. Method for imparting brilliance to stainless steel by removing a thin layer of the


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surface akin to a reverse electroplating process without any working of the underlying metal. Also known as bright finishing. The process highlights surface irregularities (i.e. roll grit pattern, pickle matte, scratches, pits and digs). At best, very special processing is required to enhance surface to be electro polished. Electroslag Refining - A specialized steel making process in which a rolled or a cast ingot in the form of an electrode is re-melted in a water cooled copper mould. The melting is activated by resistive heat generated in a conductive slag. The resulting product has a similar basic chemical composition to the original ingot, but is characterized by high purity and low inclusion content. Typical applications include high integrity components for the aerospace industry. Elevated Temperature Drawing - A process of drawing steel bars at elevated temperatures (normally 250-300oC) which under optimum conditions produce steels that have higher tensile and yield strengths than those cold drawn with the same degree of reduction. Elongation - (1) Increase in length which occurs before a metal is fractured, when subjected to stress. This is usually expressed as a percentage of the original length and is a measure of the ductility of the metal. (2) In tensile testing, the increase in the gauge length, measured after fracture of the specimen within the gauge length, usually expressed as a percentage of the original gauge length. Elongation After Fracture - In tensile testing, the increase in the gauge length measured after fracture of the specimen within the gauge length and usually expressed as a percentage of the original gauge length. Embossing - Raising or indenting a design in relief on a sheet or strip of metal by passing between rolls of desired pattern. End-Quench Hardenability Test (Jominy Test) - A laboratory procedure for determining the hardenability of a steel or other ferrous alloy. 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 - Same as fatigue limit. Maximum alternating stress which a given material will withstand for an indefinite number of times without causing fatigue failure. Epitaxy - Induced orientation of the lattice of a crystal of a surface deposit by the lattice of the substrate crystal. Equilibrium Diagram (1) A diagram constructed from thermal and other data showing the limits of composition and temperature within which the various constituents or phases of alloys are stable. (2) A graphical representation of the temperature, pressure and composition limits of phase fields in an alloy system as they exist under conditions of thermo dynamical equilibrium. In condensed systems, pressure is usually considered constant. Equiaxed Crystals - Crystals, each of which has axes approximately equal in length. These are normally present in the centre of a steel ingot. Equiaxed Structure - A structure in which the grains have approximately the same dimensions in all directions.


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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 millimeters at fracture is a measure of the ductility. Similar to the Olsen Test. Readings are in millimeters. ERW - Electric Resistance Welding (used in formation of pipe). Etchant - A chemical solution used to etch a metal to reveal structural details. Etching - (1) In metallography, the process of revealing structural details by the preferential attack of reagents on a metal surface. (2) Subjecting the surface of a metal to preferential chemical or electrolytic attack to reveal structural details. Eutectic - A mixture of two or more constituents which solidify simultaneously out of the liquid at a minimum freezing point. Eutectoid - (1) An isothermal reversible transformation in which a solid solution is converted into two or more intimately mixed solids, 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 transformation. Eutectoid Steel - Steel representing the eutectoid composition of the iron-carbon system, with about 0.80% to 0.83% carbon, the eutectoid temperature being about 1333 (degrees) F. Such steel in the annealed condition consists exclusively of pearlite. Steels with less than this quota of carbon are known as hypo-eutectoid and contain free ferrite in addition to the pearlite. When more carbon is present, the steel is known as hyper-eutectoid and contains free cementite. The presence of certain elements, such as nickel or chromium, lowers the eutectoid carbon content. 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. Expander Steel - Hardened and tempered, blue polished. Carbon content about 1.00, Chromium .17. Used for the expanders in oil piston rings. Hardness 30 N 70 to 73. Range of sizes run for grooves 3/32 to 1/4 wide with the steel approximately .003 less than the grooves and thickness from .012 to .020. Extensometer - An apparatus for indicating the deformation of metal while it is subjected to stress. Extensometer Test - The measurement of deformation during stressing in the elastic range, permitting determination of elastic properties such as properties such as proportional limit, proof stress, yield strength by the offset method and so forth. Requires the use of special testing equipment and testing procedures such as the use of an extensometer or the plotting of a stress-strain diagram. Extra Hard Temper - In brass mill terminology, Extra Hard is six B&S numbers hard or 50.15% reduction from the previous annealing or soft stage. Extra Spring Temper - In brass mill terminology. Extra Spring is ten numbers hard or 68.55% reduction in thickness from the previous annealing or soft stage. Extrusion - Shaping metal into a chosen continuous form by forcing it through a die of appropriate shape. The production of a section by forcing a billet to flow through a die. Often


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used for producing complex sections, the process is used with both hot and cold metal. Seamless tubes are produced by forcing a hot billet to flow through a die over a mandrel positioned centrally in the die. Eye of Coil - The center of the coil as wound. Face Centered (concerning cubic space lattices) - Having equivalent points at the corners of the unit cell and at the centers of its six faces. A face-centered cubic space lattice is characteristic of one of the close-packed arrangements of equal hard spheres. Fatigue - The phenomenon leading to fracture under repeated or fluctuat

Glossary of Metalworking Terms

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