Metal Glossary

on 03 December 2024. Posted in Materials

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Acid Steel - Steel melted in a furnace having an acid bottom and lining and under a slag with acid reaction. The term has no reference to the acidity of the steel.
Age Hardening - An aging process that increases hardness and strength. Ordinarily ductility decreases. Age hardening usually follows rapid cooling or cold working. Hardening is a result of a precipitation process, often sub-microscopic, which occurs when a supersaturated solid solution is naturally aged at atmospheric temperature or artificially aged in some specific range of elevated temperature. Aging occurs more rapidly at higher temperatures.
Age Softening - The loss of strength and hardness at room temperature that takes places in certain alloys due to the spontaneous reduction of residual stresses in the strain of a hardened structure.
Air Hardening - Heating a suitable grade of steel with high hardenability above the critical temperature range and then cooling in air for the purpose of hardening.
Alloy - A combination of two or more elements which can be metals or a metal and a non-metal. Alloys offer unique advantages to pure metal such as weight, cost, strength and price. In many modern applications, alloys are custom engineered to match specific requirements. Stainless steel is an alloy.
Alloy Formation - Metals can combine with other metals or elements to form alloys. Because alloys combine different elements, they contain atoms of different sizes. How these atoms combine and interact with one another gives alloys their classification. In alloy chemistry, an alloy can be classified as substitutional or interstitial, according to its atomic arrangement.
Alloy Steel - Steel containing significant quantities of alloying elements (other than carbon and the commonly accepted amounts of manganese, silicon, sulfur, and phosphorous) added to affect changes in the mechanical or physical properties.
Aluminizing - Forming an aluminum or aluminum alloy coating on a metal by hot dipping, hot spraying, or diffusion.
Annealing - Annealing is a heat treatment process which basically allows a metal to become more ductile, and generally improves workability at room temperature. When metal is annealed, it's made hot enough so the atoms are able to realign to an equilibrium state. Cooling must be slow enough so that atoms stay aligned.
Attenuation - The fractional decrease of the intensity of an energy flux, including the reduction of intensity resulting from geometrical spreading, absorption, and scattering.
Austenitic - Austenitic stainless steels are mainly composed of austenite, a non-magnetic iron allotrop (meaning it can exist in two or more forms), with 18% chromium, and 8% nickel. Austenitic stainless steels are not heat treatable.
Austenitic Stainless Steel - Low carbon, iron-chromium-nickel stainless alloys containing more that 16% chromium, with sufficient nickel to provide an austenitic structure at normal temperatures. These alloys cannot be hardened by heat treatment, but can be hardened by cold working. They are normally nonmagnetic, but can be slightly magnetic depending on composition and amount of cold working.
Austempering - A patented heat treatment process that consists of quenching an iron base alloy from a temperature above the transformation range in a medium having a high rate of heat abstraction, and then maintaining the metal, until rate of heat abstraction, and then maintaining the metal, until transformation is complete, at a substantially uniformed temperature which is below that of peralite formation and above that of martensite formation.
Austenitic Steel - Steel which has a stable austentic structure at normal (room) temperatures.

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Bainite - A decomposition product of austenite consisting of an aggregate of ferrite and carbide. In general, it forms at temperatures lower than those where very fine pearlite forms and higher than that where martensite begins to form when cooling. Its appearance is feathery if formed in the upper part of the temperature range and acicular, resembling tempered martensite, if formed in the lower part.
Bark - Decaburized skin found just beneath the scale.
Basic Steel - Steel melted in a furnace with a basic bottom and lining and under a slag having a basic reaction. Most steel made in America is basic.
Bend Test - A test commonly made by bending a cold sample of specified size and through a specific circular angle. Bend tests provide an indication of the ductility of the sample.
Bessemer Process - A process for making steel by blowing air through molten pig iron contained in a refractory lines vessel so as to remove via oxidation most of the carbon, silicon, and manganese.
Billet - A semi-finish rolled ingot of rectangular cross section or nearly so. In general the term billet is used when the cross section ranges from 4 up to 36 sq. in., the width always being less than twice the thickness. Small sizes are usually classed as bars or small billets. The term boolm is property used when the cross section about 36 sq. in., though this distinction is observed.
Binary Alloy - As the name suggest a binary alloy consists of two elements, which could be two metals or a metal and a non-metal.
Black Annealing - A process of box annealing of sheets prior to tinning whereby a black oxide color is imparted to the surface of the product.
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.
Bloom - A semifinished, 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. Iron and steel blooms are sometimes made by foraging.
Blowhole - A hole produced during the solidification of metal by evolved gas which, in failing to escape, is held in the metal.
Blue Annealing - A process of annealing sheets after rolling. The sheets, if fairly heavy, are allowed to cool slowly after the hot rolling; if of lighter gauge, as is usually the case, they are passed singly through an open furnace for heating to the proper annealing temperature. As the name indicates, the sheets have a bluish-black appearance.
Blue Brittleness - Brittleness exhibited by some steels after being heated to some temperature with the range of 300°F - 650°F, and more especially if the steel is worked at the elevated temperature. Killed steels are virtually free of this kind of brittleness.
Blueing - A method of coating sheets with a thin, even film bluish black oxide. The blued surface is obtained by exposure to an atmosphere of dry steam or air at a temperature of about 100° F. Generally this is done during box annealing.
Box Annealing - Softening steel by heating, usually at a subcritical temperature, in a suitable closed metal box or pot to protect it from oxidation, employing a slow heating and cooling cycle; also called close to annealing or pot annealing.
Bright Annealing - An annealing process usually carried out in controlled furnace atmosphere so that surface oxidation is reduced to a minimum and the surface remains relatively bright.
Brinell Hardness Number - A measurement of a material's hardness of metals and alloys, specifically its resistance to indentation. It is determined using the Brinell hardness test, which involves pressing a spherical indenter (usually a hardened steel ball) into the surface of the material under a known load. The diameter of the resulting indentation is measured, and the Brinell hardness number is calculated using a formula.
Burning - Heating steel to a temperature sufficiently close to the melting point to cause permanent injury. Such injury may be caused by the melting of the more fusible constituents, by the penetration of gases such as oxygen into the metal with consequent reactions, or perhaps by the segregation of elements already present in the metal.
Burnishing - Smoothing surfaces through frictional contact between the work and some hard pieces of material such as hardened metal balls.
Buster - A defect in metal produced by gas bubbles either on the surface or formed beneath the surface while the metal is hot or plastic. Very fine blisters are called pinhead or pepper blisters.

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Caburizing - Adding carbon to the surface of iron-based alloys by heating the metal below its melting point while in contact with carbonaceous solids, liquids, or gases. Desired hardness and toughness in properties are developed in the high-carbon case by quenching and tempering.
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 the top metal to solidify and prevents the formation of an excessive number of gas voids with the ingot. Pressure is built up in the sealed-in molten metal and results in a surface condition much like that of rimmed steel.
Carbide - A compound consisting of carbon and other elements.
Carbon Steel - Steel containing carbon up to about 2% and only residual quantities of other elements except those added for deoxidation 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 monoxide, and ammonia. The carbonitrided alloy is usually quench hardened.
Case Hardening - 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.
Cementite - A compound of iron and carbon, known chemically as iron carbonide and having the approximate chemical formula (\(Fe_3 C\)). 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.
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.
Clad Metal - A composite metal containing two or three layers that have been bonded together. The bonding may have been accomplished by corolling, welding, casting, heavy chemical deposition, or heavy electroplating.
Cold Reduction - The reduction of sectional dimensions of a tube by a number of types of cold working operations.
Cold Short - A condition of brittleness existing in some metals at temperatures below the recrystallization temperature.
Cold Sinking - Similar to cold drawing except that the tube is drawn through a die, but without an internal mandrel. Usually used for making heavy wall or small tube, where drawing over a mandrel is impractical.
Cold Working - Permanent strain produced by an external force in a metal below its recrystallization temperature.
Corrosion - The thinning of a pipe wall that is typically caused by a chemical reaction from a corroding fluid or agent and is limited almost exclusively to metal products. Examples of non-metallic corrosion include the dissolution of ceramic materials or the discoloration and weakening of polymers by the sun's ultraviolet light.
Creep - Time-dependent strain occurring under stress. The creep strain occurring at a diminishing rate is called primary creep; occurring at a minimum and almost constant rate, secondary creep; 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 rate at constant temperature.

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Dead Soft Anneal - A heat treatment applied to achieve maximum softness and ductility.
Decarburization - The loss of carbon from the surface of solid steel during heating, forging, hot rolling, etc.
Deoxidised Sheets - Hot rolled sheets that have been bright annealed.
Deoxidizer - A substance added to molten steel for the purpose of removing oxygen.
Direct Chill Casting (DC 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 semicontinuous casting.
Drop Forging - A forging made with a drop hammer.
Drop Hammer - A forging hammer than depends on gravity for its force.
Ductility - Do not confuse ductility with malleability. Ductility is the ability of a metal to be deformed under tensile stresses, or basically its ability to be stretched.
Duplex - Duplex stainless steels are made with theoretically equal ratios of ferrite and austenite, two iron allotropes, but commercially available duplex stainless is usually closer to a 40/60 mix. Duplex stainless steel is more resistant to localized corrosion, and has approximately twice the strength of traditional austenitic stainless steel such as 304, 316, etc.
Duplex (Austenitic/Ferrite) Stainless Steel - A stainless steel whose microstructure at room temperature consists primarily of a near equal mixture of austenite and ferrite.
Duralumin - A term formerly applied to the class of age-hardenable aluminum-copper alloys containing manganese, magnesium, or silicon.

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Electropositivity - The capability of an atom to donate electrons and generate positively charged cations is known as electropositivity. Metallic elements, particularly alkali metals and alkaline earth metals, are known to have this feature. Electropositivity is the reverse of electronegativity, which is a measurement of an atom’s tendency to acquire electrons and create negatively charged anions. As a result, electropositive elements have very low electronegativities, whereas highly electronegative elements have low electropositivity.
Elongation - 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.
End-Quench Harden-ability Test (Jominy Test) - A laboratory procedure for determining the harden ability of steel, commonly referred to as the Jominy test. The data are normally plotted as hardness versus distance from the quenched end.
Endurance Limit - Maximum dynamic stress to which material may be submitted for an infinite number of times without causing fatigue failure.
Eutectoid Steel - Carbon steel with a 100 per cent pearlitic structure, which is the structure developed under normal conditions of hot working and cooling when the proportion of carbon is about .80 per cent. Hypereutectoid steel has a greater percentage of carbon, and hypo-eutectoid steel has less carbon.
Extrusion Seam - A seam in aluminum tube, pipe or hollow shape resulting from the pressure bonding at two or more edges during the course of extruding through a bridge, porthole die extrusion.

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Fatigue - The tendency for a metal to break under conditions of repeated cyclic stressing below the ultimate tensile strength.
Ferro Alloy - Iron alloyed with some element such as manganese, chrome, or silicon, etc., used in adding the element to molten sheet.
Ferrite Stainless Steels - The designation used for certain straight chromium steels that exhibit microstructures consisting mainly of ferrite at ordinary temperatures. Ferritic stainless steels are divided into two classifications; hardenable, and non-hardenable. When rapidly cooled from elevated temperatures the non-hardenable grades (ferritic) have a ferritic microstructure. The hardenable grades (martenistic) will exhibit a martenistic microstructure when rapidly cooled.
Ferrous Metal - A term used to describe an alloy that contains iron. Any metal including steel, pig iron, stainless steel, etc made using an iron allotrope is considered ferrous.
Fiber Stress - Unit stress at a certain point when overall section stress is not uniform.
Finished Steel - Steel which is ready for the market without any further work or treatment such as wire, bars, sheets, rails, plates, etc.
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 and snowflakes.
Flame Annealing - The direct application of a high temperature flame to a steel surface for the purpose of removing stresses and softening the metal. Commonly used to remove stresses from welds.
Flame Hardening - In this method of hardening, the surface layer of a medium or high carbon steel is heated by a high temperature torch and then quenched.
Flash - A thin fin of meal formed at the sides of a die forging or sometimes a rolled bar where a small portion of the metal is forced out between the edges of the forging dies or rolls.
Forging - A piece of metal which has been saped or formed. while hot, by forging with a hammer (hand or power), in a press; or by a drop hammer.
Forging Stresses - Stresses resulting from forging or from cooling from the forging temperature.
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, soundness, and presence of defects.
Full Annealing - Heating to above the critical temperature range followed by slow cooling through the range, producing maximum softness.
Full Hardness - Usually the hardness of heat treated steel after quenching and before tempering.
Full Finished - Refers to stainless tube in which the weld has been processed to produce uniform strength and dimensions, and subsequently annealed to obtain proper corrosion resistance.

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Gauge - The thickness of the stainless steel or other metal. It's based on the average weight of 41.82 lb (18.96 kg) per square foot per inch thick. This basically means that at a select gauge, a 1 inch pile of said gauge should weigh 41.82 lbs. Most international standards organizations discourage the use of this system, calling it archaic and non-standard. Ferrous and non-ferrous metals use different standards gauge standards.
Galvanic Corrosion - Corrosion associated with the presence of two dissimilar metals in a solution (electrolyte). In principle, it is similar to bath-type plating in the sense that the anode surface has lost metal (corroded).
Grain Growth - The increase in the size of grains making up the microstructure of steel such as may occur during heat treatments.
Grain Refinement - Reducing the crystalline of grain structure by heat treating, or by a combination of heat treating and mechanical working.
Grain Structure - The type of crystalline structure as observed by eye or under the microscope.
Graphitizing - Annealing gray cast iron so that most of the carbon is transformed to the graphitic condition. Controlled by increasing silicon and by thermal treatment.
Gray Cast Iron - A cast iron that gives a gray fracture due to the presence of flake graphite, often called gray iron.

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Hardenability - The ability of a steel to harden with cooled form its hardening temperature as measured by its surface hardness and by the depth of hardening below the surface.
Hardening - Refers to a metalworking or metallurgical process that increases hardness of stainless steel and other metals. There are five methods, including Hall-Petch method, Work Hardening, Solid Solution Strengthening, Precipitation Hardening, and Martenistic Transformation. They all basically translate into the same thing, which is to increase resistance to change on the molecular level.
Hardenability - In a ferrous alloy, the property that determines the depth and distribution of hardness induced by quenching.
Heat of Steel - The steel produced from one charge in the furnace, and consequently practically identical in its characteristics.
Heat Resisting Steels - Those steels which are used for service at relatively high temperatures because they retain much of their strength and resist oxidation under such conditions.
Heat Treatment - Heat treating includes a broad range of metallurgical processes through which stainless steel and other metals are changed physically and sometimes chemically. There are quite a number of heat treatment processes, including annealing, aging, quenching, tempering, and selective heat treatment.
Heat Treatment of Aluminum - Aluminum alloys are divided into two distinct groups based on their reaction to thermal treatment. Heat-treatable tube alloys (2000, 6000, and 7000 series) can be strengthened by thermal treatment and subjected to repeated heat treatment cycles without harmful effects. Non-heat-treatable tube alloys (1000, 3000, and 5000 series) can be strengthened only by cold working.
Heat Treatment of Steel - A combination of heating and cooling operations applied to a metal or alloy in the solid state to obtain desired conditions or properties. Heating for the sole purpose of hot working is excluded from the meaning of this definition.
Homogenizing - A high-temperature soaking treatment to eliminate or reduce segregation by diffusion. Performed on the ingot at 900°F - 1,000°F temperature range.
Hot Top - A reservoir, thermally insulated or heated, to hold molten metal on top of a mold to feed the ingot or casting as it contracts when solidifying to avoid having pipe or voids.
Hot Working - The mechanical working of metal above the recrystalization temperature.

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Inclusions - Particles of non-metallic material usually oxides, suphides, silicates and such which are entrapped mechanically or are formed during solidification or by subsequent reaction within the solid metal.
Ingot Iron - Open hearth iron low in carbon, manganese and other impurities.
Intergranular Corrosion - Corrosion which occurs preferentially along the grain boundaries of the alloy.
Interstitial Alloy - In an interstitial alloy, the atoms of one material are too small to displace the larger atoms of the other material, so they end up nested in between them, in gaps known as interstices. Steel is an interstitial alloy because the carbon atoms sit between the iron atoms. Stainless steel is a mix of interstitial and substitutional alloys.
Iron Ore - Iron ore is any rock or mineral containing metallic iron. According to the Mineral Information Institute, over 98% of iron currently being mined in the world today is used in steel production.
Izod Test - A test made to determine the notched toughness of a material. The test gives the energy required to break a standard notched specimen supported as a cantilever beam.

J

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Killed Steel - Steel in which sufficient deoxidizing agents have been added to prevent gas evolution during solidification.

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Lap - A surface defect appearing as a seam caused from folding over hot metal, fins, or sharp corners and then rolling or forging, without welding them into the surface.

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Machinability - Straightening metal bars by rolling in a straightening machine.
Malleabilizing - An annealing operation performed on white cast iron for the purpose of partially or wholly transforming the combined carbon to temper carbon, and in some cases to remove completely the carbon from the iron by decarburization.
Martensitic - Martenistic stainless steel is made when austenitic stainless is cooled rapidly enough that the high carbon concentrations are not able to diffuse out of the material on an atomic level. Basically, martenistic stainless has more carbon atoms. It's harder and more ductile than austenitic stainless.
Mechanical Working - Working metal through rolls, presses, hammers, etc., to change its shape, properties or structures.
Modulus of Elasticity - The measures the stiffness of an elastic material. The ratio of the longitudinal stress applied to a body or substance to the resulting longitudinal strain within the elastic limits. It represents the slope of the stress-strain curve within the elastic region of a material.
Molybdenum (Mo) - his is a medium hardness element with an extremely high melting point and the ability to "harden" metal alloys. Molybdenum is used to create high strength stainless steel alloys among others and composes roughly 0.25% to 8% of the metal.

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Network Structure - A structure in which the crystals of one constituent are partially or entirely surrounded by envelopes of another constituent, an arrangement that gives a network appearance to a polished and etched specimen.
Nickel (Ni) - An element that is corrosion resistant, hard, yet ductile, and is magnetic at room temperature. Due to its high melting point and corrosion resistance, Nickel is used as an alloying agent in stainless steel to retain its chemical properties from extreme cold to the melting point.
Nickel Steel - Alloy steel containing nickel as its principal alloying element.
Nitriding - Adding nitrogen to the solid iron base alloys by heating at a temperature below the critical in contact with ammonia or other nitrogenous material.

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Oil Quench - A quench from the hardening temperature, in which oil is the cooling medium.
Overheating - Heating to such a temperature that, while the properties of the metal are impaired, it has not been burned and can therefore be restored by heat treatment.

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Passivation Layer - Molecular, oxide (corrosion) layers formed on the surface of metals through corrosion that basically protect the metal from further corrosion and damage. Passivation layers vary in thickness and actually grow thicker over time on many materials such as aluminum.
Physical forms - Most metals are naturally solid at room temperature, except for mercury, which is liquid at room temperature. In physical form, metals can be defined as substances, which have a bright luster and are good conductors of heat and electricity. They have varying degrees of density, hardness, malleability and ductility.
Pig Spout - A sheet metal section designed to direct the flow of water out through the face of the gutter rather than through a downspout.
Pitting Corrosion - Non-uniform corrosion usually forming small cavities in the metal surface.
Precipitation Hardening - Also known as age hardening, this method of hardening involves heat treating a metal for prolonged periods of time to allow the formation of impurities or different sized particles. This basically serves to harden the material by restricting the movement of atoms within the metal when cooled.

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Quenching - A type of heat treatment involving the rapid cooling of stainless steel or some other metal. Quenching helps cool the metal quickly enough so that crystal structures aren't able to form, thus increasing the hardness, as well as so called "toughness." Quenching medias include air, nitrogen, argon, helium, brine (salt water), oil and water.
Quenching Medium - The medium used for cooling steel during heat treatment, usually oil, water, air, or salts.
Quenching Temperature - The temperature from which steel is quenched during a heat treating process.

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Reactivity - React with oxygen to form metal oxides (rust in iron). Reactive metals lose electrons easily and produce vigorous (explosive or potentially dangerous) reactions with water or acids. Unreactive metals do not lose electrons easily and are inert under normal conditions and with substances they are likely to encounter.
Recalescence - The liberation of heat due to internal changes, which occurs when steel is cooled through the critical temperature range.
Rimmed Steel - A steel that is poured containing enough oxygen to evolve appreciable gas during solidification. The gas evolution results in a finished product having a very pure surface with the impurities concentrated in the interior. The pure zone which is readily shown by etching is referred to as the rim.

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Scab - A defect on the ingot caused by metal which splashes during teeming; on rolled or forged products it appears as a silver-like defect partially welded or mechanically bound to the parent metal surface.
Seam - An elongated discontinuity in metal caused by a blowhole or other defect which has been closed by rolling or forging mechanically but not welded.
Secondart Hardening - An increase in hardness following the normal softening during the tempering of certain alloy steels.
Siliconizing - Diffusing silicon into solid metal, usually steel, at an elevated temperature.
Skelp - Steel or iron plate from which pipe or tubing is made.
Slab - Steel or Iron plate from which pipe or tubing is made.
Slabbing Mill - A mill for rolling slabs from ingots.
Slack Quenching - The process of hardening steel by quenching from the austenitizing temperature at a rate slower than the critical cooling rate for the particular steel, resulting in incomplete hardening and the formation of one or more transformation products in addition to, or instead of, martensite.
Soaking - Holding steel at a a predetermined temperature for a sufficient time to assure heat penetration and/or to complete the solution of carbides.
Soft Anneal - When maximum softness and ductility are required without change in grain structure, material should be ordered soft annealed. This process consists of heating to a temperature slightly below the critical temperature and cooling still in the air. Usually performed in the 1,250°F to 1,350°F range for carbon steel.
Solidification Range - The temperature range through which metal freezes or solidifies.
Solid Solution - A condition wherein one element is dissolved in another element while the dissolving element is in a solid and not liquid condition.
Solution Anneal - Heating steel into a temperature range wherein certain elements or compounds dissolve, followed by cooling at a rate sufficient to maintain these elements in solution at room temperature. The expression is normally applied to stainless and other special steels.
Solution Heat Treating - Heating an alloy at a suitable temperature for sufficient time to allow soluble constituents to enter into solid solution where they are retained in a super-saturated state after quenching. Performed in the temperature range of 825°F - 980°F depending on heat-treatable aluminum alloy and followed by aging.
Sorbite - A fine mixture of ferrite and cementite produced either by regulating the rate of cooling of steel or tempering steel after hardening. The first type is very fine pearlite difficult identify under the microscope; the second type is tempered martensite.
Spheroidizing - Any of a number of processes of heating and cooling which cause the carbides to assume a spherical-like shape. Ordinary steel are commonly spherodized by prolonged heating at temperature just below the lower limit of the transformation range with subsequent slow cooling.
Spheroidizing Anneal - A general term that refers to heat treatments that promote spheroidal or globular forms of carbide in carbon or alloy steels.
Stabilizing Anneal - A treatment applied to austenitic stainless steels wherein carbides of various forms are deliberately precipitated. Sufficient additional time is provided at the elevated temperature to diffuse chromium into areas adjacent to the carbides (usually grin boundaries). This treatment is intended to lessen the change of intergranular corrosion.
Stainless Steel - A type of alloy that is known for its exceptional corrosion resistance, strength, and versatility. It is composed primarily of iron, along with varying amounts of chromium, nickel, molybdenum, and other elements, depending on the specific grade and composition. The addition of these alloying elements imparts the unique properties that make stainless steel highly useful in a wide range of applications.
Stress Relief Anneal - Often referred to as finish annealing, involves 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 relieving normally takes place in the 950°F - 1,150°F temperature range for carbon steel.
Stretcher Leveling - A method of producing unusual flatness in steel sheets bu stretching them in a hydraulic device.
Substitutional Alloy - n alloy where the atoms are similarly sized, and unlike an interstitial alloy, the atoms will displace each other instead of nesting. Stainless steel is both a substitutional and interstitial alloy because carbon atoms nest between the iron atoms, but the nickel and chromium atoms displace iron atoms.
Superalloy - An alloy developed for very high temperature service where relatively high stresses (tensile, thermal, vibratory, and shock) are encountered and where oxidation resistance is frequently required.

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Tapping - Removing molten metal from a furnace.
Teeming - Pouring steel from the ladle to the molds.
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 revealed by notched-bar impact tests at or below room temperature.
Tempering - A heat treatment method used to toughen metal, as in make it more shock resistant. Once a metal has been hardened through any of the dozen processes, it's once again heated to a temperature below the critical point. Basically, it's heated to a point where some atom reconfiguration is allowed to occur, which reduces excess hardness hardness, and makes the metal more resistant to breakage.
Tensile Strength - The maximum stress a material can resist before it starts to elongate. Ultimate tensile strength is a mechanical property that represents the maximum stress a material can withstand before it fractures or breaks under tensile loading. It is a measure of the material's resistance to being pulled apart or stretched.
Ternary Alloy - This is simply an alloy created using three elements. With metals, the base element, or primary constituent is iron, and the 2 additional elements are the secondary constituents. Stainless steel is a ternary alloy because it contains iron, chromium, and nickel.
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.

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Vanadium (V) - hard, silvery gray metal that is both ductile and malleable. It greatly increases the strength of steel when added in small quantities due to the formation of high strength, stable bonds within the metal. Vanadium is also used to create very hard steel for machining applications, surgical instruments, and some cutlery.

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Water Quench - Cooling steel from its quenching temperature with water.
Welding - The fabrication process that fuses like materials togeather by heating them to a suitable temperatures, this can be acomplished by brazing, soldering or welding. The filler metal has a melting point approximately the same or below that of the metals being joined togeather.
Work Hardening - Processes such as hammering, rolling, bending, stretching, etc strain metal beyond it's yield point and create dislocations. These are essentially areas where additional atoms are pulling at each other. Continued cold working increases dislocations, and eventually the atoms resist all further attempts at dislocation, at which point the material is as hard as it can get without breaking.
Wrought Iron - A commercial iron consisting of slag (iron silicate) fibers entrained in a ferrite matrix.

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Zinc-Aluminum Coated - Steel coated with an alloy of zinc and aluminum to provide corrosion resistance.

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