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.

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.

• A represents basic open-hearth 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

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 910°C 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.

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.

Al
Atomic Number: 13
Melting Point: 933.437 K (660.323°C or 1220.581°F)
Boiling Point: 2792 K (2519°C or 4566°F)
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:

• Deoxidizes efficiently.
• Restricts grain growth (by forming dispersed oxides or nitrides)
• 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.

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.

The process of heating and cooling a cold reduced sheet to induce softness and formability. Two types:

• box annealing (Cold Sheet Mill)
• continuous annealing (Galvanize Mill)

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.

Abbreviation for American 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.

A solid solution of one or more elements in face-centered cubic iron.

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°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.

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.

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:

• Form sheet bar on single stand sheet mills or sheet mills in tandem. This method is now almost obsolete.
• 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.

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.

Modern Definition: a semi-finished hot rolled steel product, rectangular in section, usually produced on a blooming mill but sometimes made by forging.

Also: 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.

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.

Subjecting the scale-free surface of a ferrous alloy to the action of air, steam, or other agents at a suitable temperature, thus forming a thin blue film of oxide and improving the appearance and resistance to corrosion.

NOTE: This term is ordinarily applied to sheet, strip, or finished parts, It is used also to denote the heating of springs after fabrication in order to improve their properties.

B
Atomic Number: 5
Atomic Weight: 10.811
Melting Point: 2348 K (2075°C or 3767°F) Boiling Point: 4273 K (4000°C or 7232°F) 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.

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.

Permanently damaging a metal or alloy by heating to cause either incipient melting or intergranular oxidation.

In grinding getting the work hot enough to cause discoloration or to change the microstructure by tempering or hardening.

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.

Joining two edges or ends by placing one against the other and welding them.

The type of welding that fuses the head end of one coil to the tail end of another, using heat, without overlapping the strip.

Ca
Atomic Number: 20
Atomic Weight: 40.078
Melting Point: 1115 K (842°C or 1548°F)
Boiling Point: 1757 K (1484°C or 2703°F)
Density: 1.54 grams per cubic centimeter
Phase at Room Temperature: Solid

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.

Deviation from edge straightness usually referring to the greatest deviation of side edge from a straight line.

Sometimes used to denote crown in rolls where the center diameter has been increased to compensate for deflection cause by the rolling pressure.

Edgewise curvature. A lateral departure of a side edge of sheet or strip metal from a straight line.

C
Atomic Number: 6
Atomic Weight: 12.0107
Melting Point: 3823 K (3550°C or 6422°F)
Boiling Point: 4098 K (3825°C or 6917°F)
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.

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].

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.

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.

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.

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.

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.

A term indicating in the annealed state as Cast Spring Steel Wire.

In reference to Bright or Polished Strip Steel or Wire, the word cast implies discoloration as a shadow.

A term implying a lack of straightness as in a coil set.

An object at or near finished shape obtained by solidification of a substance in a mold.

Pouring molten metal into a mold to produce an object of desired shape.

Introduction of one or more elements into the outer layer of a metal object by means of diffusion at high temperature.

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.

Ce
Atomic Number: 58
Atomic Weight: 140.116
Melting Point: 1071 K (798°C or 1468°F)
Boiling Point: 3697 K (3424°C or 6195°F)
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.

A beveled surface to eliminate an otherwise sharp corner.

A relieved angular cutting edge at a tooth corner.

Cr
Atomic Number: 24
Atomic Weight: 51.9961
Melting Point: 2180 K (1907°C or 3465°F) Boiling Point: 2944 K (2671°C or 4840°F)
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 principal functions as an alloy in steel making:

• Increases resistance to corrosion and oxidation
• Increases harden-ability
• Adds some strength at high temperatures
• Resists abrasion and wear (with high carbon). Straight chromium steels are susceptible to temper embrittlement and can be brittle

Co
Atomic Number: 27
Atomic Weight: 58.933200
Melting Point: 1768 K (1495°C or 2723°F)
Boiling Point: 3200 K (2927°C or 5301°F)
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.

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.

Reduction of strip thickness through the use of force rather than heat.

A discontinuity that appears on the surface of cast metal as a result of two streams of liquid meeting and failing to unite.

A portion of the surface of a forging that is separated, in part, from the main body of metal by oxide.

A condition of brittleness existing in some metals at temperatures below the recrystallization temperature.

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.

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.

Cu
Atomic Number: 29
Atomic Weight: 63.546
Melting Point: 1357.77 K (1084.62°C or 1984.32°F)
Boiling Point: 2835 K (2562°C or 4644°F)
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.

Gradual chemical or electrochemical attack on a metal by atmosphere, moisture or other agents.

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

The maximum stress that will cause less than a specified quantity of creep in a given time.

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.

The constant nominal stress that will cause a specified quantity of creep in a given time at constant temperature.

The constant nominal stress that will cause a specified creep react at constant temperature.

The temperature or pressure at which a change in crystal structure, phase, or physical properties occurs. Same as transformation temperature.

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.

Temperatures at which internal changes or transformations take place within a metal either on a rising or falling temperature.

The rolling of sheet so that the direction of rolling is changed about 90 (degrees) from the direction of the previous rolling.

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.

Deviation from flat across the strip width.

A physically homogeneous solid in which the atoms, ions, or molecules are arranged in a three-dimensional repetitive pattern.

A coherent piece of matter, all parts of which have the same anisotropic arrangement of atom; in metals, usually synonymous with grain and crystallite.

Removal of oxygen from molten metals by use of suitable chemical agents.

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.

Spreading of a constituent in a gas, liquid or solid, tending to make the composition of all parts uniform.

The spontaneous movement of atoms or molecules to new sites within a material.

Forming recessed parts by forcing the plastic flow of metal in dies.

Reducing the cross section of wire or tubing by pulling it through a die.

A misnomer for tempering.

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.

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:

• Decorative and protection against corrosion; copper, nickel and chromium
• Protection against corrosion; cadmium or zinc
• Protection against wear; chromium
• Build-up of a part or parts undersize; chromium or nickel
• Pate for rubber adhesion; brass
• 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.

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.

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.

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.

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.

In metallography, the process of revealing structural details by the preferential attack of reagents on a metal surface.

Subjecting the surface of a metal to preferential chemical or electrolytic attack to reveal structural details.

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.

An alloy having the composition indicated by the eutectoid point on an equilibrium diagram.

An alloy structure of intermixed solid constituents formed by a eutectoid transformation.

The characteristic of wrought metal that indicates directional properties. It is revealed by etching a longitudinal section or manifested by the fibrous appearance of a fracture. It is caused chiefly by extension of the constituents of the metal, both metallic and nonmetallic, in the direction of working.

The pattern of preferred orientation of metal crystal after a given deformation process. Direction in which metals have been caused to flow, as by rolling, with microscopic evidence in the form of fibrous appearance in the direction of flow.

Local stress through a small area (a point or line) on a section where the stress is not uniform, as in a beam under a bending load.

Unit stress which exists at any given point in a structural element subjected to load; given as load per unit area.

In forging, the excess metal forced between the upper and lower dies.

In die casting, the fin of metal which results form leakage between the mating die surfaces.

In resistance butt welding, a fin formed perpendicular to the direction of applied pressure.

Texture showing the direction of metal flow during hot or cold working. Flow lines often can be revealed by etching the surface or a section of a metal part.

In mechanical metallurgy, paths followed by volume elements of metal during deformation. Always visible to a greater or less degree when a longitudinal section has been subjected to Macro etching, indicating the direction of working or rolling.

In refining, a material used to remove undesirable substances as a molten mixture. It may also be used as a protective covering for molten metal.

In welding, a material used to prevent the formation of, or to dissolve and facilitate the removal of, oxides and other undesirable substances.

Annealing a ferrous alloy by austenitizing and then cooling slowly through the transformation range. The austenitizing temperature to hypo-eutectoid steel is usually above Ac3; and for hypereutectoid steel, usually between Ac1 and Ac (cm). Used principally on iron and steel, means heating the metal to about 100°F above the critical temperature range, followed by soaking at this point and slow cooling below the critical temperature.

An annealing treatment in which a steel is ausenitized by heating to a temperature above the upper critical temperature (A3 or Acm) and then cooled slowly to room temperature. A typical cooling rate would be 210F/h 100 C/h. Compare normalizing. Use of the term annealing without qualification implies full annealing.

(No. 1 Temper) In low carbon sheet or strip steel, stiff and springy, not suitable for bending in any direction. It is the hardest temper obtainable by hard cold rolling.

In Stainless Steel Strip, tempers are based on minimum tensile or yield strength. For Chromium-Nickel grades Full Hard temper is 185,000 TS, 140,000 YS Min. Term also used in connection with copper base alloys and considered synonymous with Hard Temper.

The damaging of one or both metallic surfaces by removal of particles from localized areas due to seizure during sliding friction.

Developing a condition on the rubbing surface of one or both mating parts where excessive friction between high spots results in localized welding with substantial spalling and a further roughening of the surface.

A solid polyhedral (or many sided crystal) consisting of groups of atoms bound together in a regular geometric pattern. In mill practice grains are usually studied only as they appear in one plane.

• (Direction of) Refers to grain fiber following the direction of rolling and parallel to edges of strip or sheets.
• To bend across the grain is to bend at right angles to the direction of rolling.
• To bend with the grain is to bend parallel to the direction of rolling. In steel, the ductility in the direction of rolling is almost twice that at right angles to the direction of rolling.

An individual crystal in a polycrystalline metal or alloy, including twinned regions or sub-grains if present.

For metals, a measure of the areas or volumes of grains in a polycrystalline material, usually expressed as an average when the individual sizes are fairly uniform. Grain sizes are reported in terms of grains per unit area or volume, average diameter, or as a grain-size number derived form area measurements. Average diameter of grains in the metal under consideration, or alternatively, the number of grains per unit area. Since increase in grain size is paralleled by lower ductility and impact resistance, the question of general grain size is of great significance. The addition of certain metals affects grain size, for example vanadium and aluminum tend to give steel a fine grain. The ASTM has set up a grain size standard for steels, and the McQuaid-Ehn Test has been developed as a method of measurement.

Average diameter of grains in the metal under consideration, or alternatively, the number of grains per unit area. Since increase in grain size is paralleled by lower ductility and impact resistance, the question of general grain size is of great significance. The addition of certain metals affects grain size, for example vanadium and aluminum ten to give steel a fine grain.

In low carbon cold-rolled strip steel, produced by cold rolling to a hardness next to but somewhat softer than full hard temper.

In brass mill terminology, half hard is two B&S numbers hard or 20.70% thickness reduction.

In Stainless Steel Strip, Tempers are based on minimum tensile or yield strength. For Chromium-Nickel grades Half-Hard Temper 150,000 T.S., 110,000 Y.S.Min.

For steel, see Full Hard Temper.

In brass mill terminology, Hard Temper is four B&S numbers hard or 37.1% reduction.

Increasing hardness by suitable treatment, usually involving heating and cooling. When applicable, the following more specific terms should be used:

• Age hardening
• Case hardening
• Flame hardening
• Induction hardening
• Precipitation hardening
• Quench hardening

Any process which increases the hardness of a metal. Usually heating and quenching certain iron base alloys from a temperature either within or above the critical temperature range.

Degree to which a metal will resist cutting, abrasion, penetration, bending and stretching. The indicated hardness of metals will differ somewhat with the specific apparatus and technique of measuring. Tensile Strength also is an indication of hardness.

For details concerning the various types of apparatus used in measuring hardness, See Brinell Hardness, Rockwell Hardness, Vickers Hardness, Scleroscope Hardness.

Holding at high temperature to eliminate or decrease chemical segregation by diffusion.

An annealing treatment carried out at a high temperature, approaching the solidus temperature, for a sufficiently long time that inhomogeneous distributions of alloying elements are reduced by diffusional processes.

Brittleness of metal, resulting from the occlusion of hydrogen (usually as a by- product of pickling or by co-deposition in electroplating).

A condition of low ductility resulting from hydrogen absorption and internal pressure developed subsequently. Electrolytic copper exhibits similar results when exposed to reducing atmosphere at elevated temperatures.

Casting metal into a mold produced by surrounding (investing) an expendable pattern with a refractory slurry that sets at room temperature after which the wax, plastic, or frozed mercury pattern is removed through the use of heat. Also called precision casting, or lost-wax process.

A casting made by the process.

Fe
Atomic Number: 26
Atomic Weight: 55.845
Melting Point: 1811 K (1538°C or 2800°F)

A magnetic silver white metal of high tensile strength, ductile and malleable. Chemically iron is chiefly base forming. The principal forms of commercial iron are steel, cast iron and wrought iron. An element that has an average atomic number of 55.85 and that always, in engineering practice, contains small but significant amounts of carbon. Thus iron-carbon alloys containing less than about 0.1% C may be referred to as irons. Alloys with higher carbon contents are always termed steels.

Pb
Atomic Number: 82
Atomic Weight: 207.2
Melting Point: 600.61 K (327.46°C or 621.43°F)

Improves machinability. It does not dissolve in steel but stays as globules. Environmental concerns are resulting in a decreased usage of lead in the steel industry.

A term applied to Open-Hearth steel wire in the .45/.75 carbon range either hard drawn or oil tempered. Oil tempered wire of M B and W M B types are the most widely used of all spring wires. Oil tempered wire is more suitable to precision forming and casting operations than hard drawn wire, because of close control of tensile strength and superior straightness.

NOTE: M B, H B and extra H B designate Basic Open Hearth steels, while W M B, W H B and extra W H B designate Acid Open Hearth Steels. The chemical composition and the mechanical properties are the same for both basic and acid steel.

Mn
Atomic Number: 25
Atomic Weight: 54.938049
Melting Point: 1519 K (1246°C or 2275°F)
Boiling Point: 2334 K (2061°C or 3742°F)
Density: 7.3 grams per cubic centimeter
Phase at Room Temperature: Solid

Lustrous, reddish-white metal of hard brittle and, therefore, non-malleable character. The metal is used in large quantities in the form of Spiegel and Ferromanganese for steel manufacture as well as in manganese and many copper-base alloys. Its principal function is as an alloy in steel making:

• It is ferrite-strengthening and carbide forming element. It increases hardenability inexpensively, with a tendency toward embrittlement when too high carbon and too high manganese accompany each other.
• It counteracts brittleness from sulfur. It is important because it deoxidizes the melt and facilitates hot working of the steel by reducing the susceptibility to hot shortness. It combines with sulfur to form MnS stringers which increases machinability. Manganese contributes to the effectiveness of normalizing for strengthening, to the formation of fine pearlite, and lowers the Ms temperature, therefore increasing the probability of retained austenite.

A hardening procedure in which an austenitized ferrous material is quenched into an appropriate medium at a temperature just above the Ms temperature of the material, held in the medium until the temperature is uniform through-out, but not long enough for bainite to form - and then cooled in air. The treatment is frequently followed by tempering.

When the process is applied to carburized material, the controlling Ms temperature is that of the case. This variation of the process is frequently called marquenching. Quenching an austenitized ferrous alloy in a medium at a temperature in the upper part of the martensite range, or slightly above that range, and holding it in the medium until the temperature throughout the alloy is substantially uniform. The alloy is then allowed to cool in air through the martensite range.

In an alloy, a metastable transitional structure intermediate between two allotropic modifications whose abilities to dissolve a given solute differ considerably, the high-temperature phase transformed to martensite depends to a large extent upon the temperature attained in cooling, there being a rather distinct beginning temperature.

A metastable phase of steel, formed by a transformation of austenite below the Ms (or Ar) temperature. It is an interstitial supersaturated solid solution of carbon in iron having a body-centered tetragonal lattice. Its microstructure is characterized by an acicular, or needle-like, pattern. A distinctive needle like structure existing in steel as a transition stage in the transformation of austenite. It is the hardest constituent of steel of eutectoid composition. It is produced by rapid cooling from quenching temperature and is the chief constituent of hardened carbon tool steels. Martensite is magnetic.

Element intermediate in luster and conductivity between the true metals and non-metals. Arsenic, antimony, boron, tellurium, and selenium, etc., are generally considered metalloids; frequently one allotropic modification of an element will be non-metallic, another metalloid in character. Obviously, no hard and fast line can be drawn.

In steel metallurgy, metalloid has a specialized, even if erroneous, meaning; it covers elements commonly present in simple steel; carbon, manganese, phosphorus, silicon and sulfur.

Element intermediate in luster and conductivity between the true metals and nonmetals. Arsenic, antimony, boron, tellurium, and selenium, etc. are generally considered metalloids; frequently one allotropic modification of an element will be non-metallic, another metalloid in character. Obviously, no hard and fast line can be drawn.

In steel metallurgy, metalloid has a specialized, even if erroneous, meaning; it covers elements commonly present in simple steel; carbon manganese, phosphorus, silicon and sulfur.

An optical instrument designed for both visual observation and photomicrography of prepared surfaces of opaque materials at magnifications ranging from about 25 to about 1500 diameters.

A measure of the rigidity of metal. Ratio of stress, within proportional limit, to corresponding strain. Specifically, the modulus obtained in tension or compression is Young's modulus, stretch modulus or modulus of extensibility.

The modulus obtained in torsion or shear is modulus of rigidity, shear modulus or modulus of torsion.

The modulus covering the ratio of the mean normal stress to the change in volume per unit volume is the bulk modulus.

The tangent modulus and secant modulus are not restricted within the proportional limit; the former is the slope of the stress-strain curve at a specified point; the latter is the slope of a line from the origin to a specified point on the stress-strain curve. Also called elastic modulus and coefficient of elasticity.

Mo
Atomic Number: 42
Atomic Weight: 95.94
Melting Point: 2896 K (2623°C or 4753°F)
Boiling Point: 4912 K (4639°C or 8382°F)
Density: 10.2 grams per cubic centimeter Phase at Room Temperature: Solid

Hard, tough metal of grayish-white color, becoming very ductile and malleable when properly treated at high temperatures. Pure molybdenum can best be obtained as a black powder, by reduction of molybdenum trioxide or ammonium molybdate with hydrogen. From this powder, ductile sheet and wire are made by powder metallurgy techniques; these are used in radio and related work. Its principal functions as an alloy in steel making:

• Raises grain-coarsening temperature of austenite.
• Deepens hardening.
• Counteracts tendency toward temper brittleness.
• Raises hot and creep strength, red hardness.
• Enhances corrosion resistance in stainless steel.
• Forms abrasion-resisting particles. It increases hardenability of steels and helps maintain a specified hardenability. It increases high temperature tensile and creep strengths.

Molybdenum hardened steels require higher tempering temperatures for softening purposes.

Ni
Atomic Number: 28
Atomic Weight: 58.6934
Melting Point: 1728 K (1455°C or 2651°F)
Boiling Point: 3186 K (2913°C or 5275°F)
Density: 8.912 grams per cubic centimeter
Phase at Room Temperature: Solid

Silvery white, slightly magnetic metal, of medium hardness and high degree of ductility and malleability and resistance to chemical and atmospheric corrosion. Used for electroplating. Used as an alloying agent, it is of great importance in iron-base alloys in stainless steels and in copper-base alloys such as Cupro-Nickel, as well as in nickel-base alloys such as Monel Metal. Its principal functions as an alloy in steel making:

• Strengthens unquenched or annealed steels.
• Toughens pearlitic-ferritic steels (especially at low temperature).
• Renders high-chromium iron alloys austenitic. It is used in low alloy steels to reduce the sensitivity of the steel to variations in heat treatment and distortion and cracking on quenching. It also improves low temperature toughness and hardenability.

Nb (was known as Columbium - Cb)
Atomic Number: 41
Atomic Weight: 92.90638
Melting Point: 2750 K (2477°C or 4491°F)
Boiling Point: 5017 K (4744°C or 8571°F)
Density: 8.57 grams per cubic centimeter
Phase at Room Temperature: Solid

It is steel gray in color and brilliant luster. It is used mainly in the production of stabilized austenitic chromium-nickel steels, also to reduce the air-hardening characteristics in plain chromium steels of the corrosion resistant type. It lowers transition temperature and raises the strength of low carbon steel. Niobium increases strength at elevated temperatures, results in finer grain size and forms stable carbides, lowering the hardenability of the steel.

N
Atomic Number: 7
Atomic Weight: 14.0067
Melting Point: 63.15 K (-210.00°C or -346.00°F)
Boiling Point: 77.36 K (-195.79°C or -320.44°F)
Density: 0. 0012506 grams per cubic centimeter
Phase at Room Temperature: Gas

Increases the strength, hardness and machinability of steel, but it decreases the ductility and toughness. In aluminum killed steels, nitrogen combines with the aluminum to provide grain size control, thereby improving both toughness and strength. Nitrogen can reduce the effect of boron on the hardenability of steels.

A heat treatment applied to steel, Involves heating above the critical range followed by cooling in still air. Is performed to refine the crystal structure and eliminate internal stress.

Heating a ferrous alloy to a suitable temperature above A3 or Acm and then cooling in still air to a temperature substantially below A1. The cooling rate usually is in the range 900 to1800 F/h (500 to 1000C/h).

The first structurally stable particle capable of initiating recrystallization of a phase or the growth of a new phase, and separated form the matrix by an interface.

The heavy central core of an atom, in which most of the mass and the total positive electrical charge are concentrated.

A reaction in which there is an increase in valence resulting from a loss of electrons.

Chemical combination with oxygen to form an oxide. The addition of oxygen to a compound. Exposure to atmosphere sometimes results in oxidation of the exposed surface, hence a staining or discoloration. This effect is increased with temperature increase.

A term indicating the process of passing metal through a rolling mill.

A single transfer of metal through a stand of rolls.

The open space between two grooved rolls through which metal is processed.

The weld metal deposited in one run along the axis of a weld.

Treatment of steel, usually in wire form, in which the metal is gradually heated to about 1830°F, with subsequent cooling, usually in air, in a bath of molten lead, or in a fused salt mixture held between 800°F and 1050°F.

A heat treatment applied to medium and high-carbon steel prior to cold drawing to wire. The treatment involves austenitization followed by isothermal transformation at a temperature that produces a microstructure of very fine pearlite.

A eutectoid transformation product of ferrite and cementite that ideally has a lamellar structure, but is always degenerate to some extent.

Lamellar structure resembling mother of pearl.

A compound of iron and carbon occurring in steel as a result of the transformation of austenite into aggregations of ferrite and iron carbide.

A copper-base alloy containing up to 10% tin, which has been deoxidized with phosphorus in varying amounts of less than 1%. Temper is imparted by cold rolling, resulting in greater tensile strength and hardness than in most copper-base alloys or either of its alloying elements copper or tin. The various tempers from One Number Hard to Ten Numbers Hard are classified in hardness by the number of B&S Gages reduction in dimension from the previous soft or as-annealed state.

Phosphor Bronze is not heat treatable for purposes of hardness development. It does not withstand elevated temperatures very well and should not be used in service above 225°F even after stress relieving treatment at 325° to 350°F. It has excellent electrical properties, corrosion resistant comparable to copper; great toughness and resistance to fatigue. Rated good for soft soldering, silver alloy brazing, oxyacetylene, carbon arc and resistance welding.

P
Atomic Number: 15
Atomic Weight: 30.973761
Melting Point: 317.30 K (44.15°C or 111.47°F)
Boiling Point: 553.65 K (280.5°C or 536.9°F)
Density: 1.82 grams per cubic centimeter
Phase at Room Temperature: Solid

Non-metallic element occurring in at least three allotropic forms; melting point 111 (degrees) F.; boiling point 536 (degrees) F.; specific gravity 1.82. In steels it is usually undesirable with limits set in most specifications. However, it is specified as an alloy in steel to prevent the sticking of light-gage sheets; to a degree it strengthens low carbon steel; increases resistance to corrosion, and improves machinability in free-cutting steels. In the manufacture of Phosphor Bronze it is used as a deoxidizing agent.

The central cavity formed by contraction in metal, especially ingots, during solidification.

The defect in wrought or cast products resulting from such a cavity.

An extrusion defect due to the oxidized surface of the billet flowing toward the center of the rod at the back end.

A tubular metal product, cast or wrought.

A general term used to describe heating applied as a preliminary to some further thermal or mechanical treatment.

A term applied specifically to tool steel to describe a process in which the steel is heated slowly and uniformly to a temperature below the hardening temperature and is then transferred to a furnace in which the temperature is substantially above the preheating temperature.

Heating a metal to a relatively high temperature for a relatively long time in order to change the structure before working. Ingots are homogenized by preheating.

The stress that will cause a specified small permanent set in a material.

A specified stress to be applied to a member or structure to indicate its ability to withstand service loads.

In low carbon cold-rolled strip steel, a medium soft temper produced by a limited amount of cold rolling after annealing.

In brass mill terminology. Quarter hard is one B and S number hard or 10.95% reduction.

In stainless steel terminology tempers are based on minimum tensile, or yield strength. For Chromium-Nickel grades Quarter Hard Temper is 125,000 T. S., 75,000 Y.S. min.

In the heat treating of metals, the step of cooling metals rapidly in order to obtain desired properties; most commonly accomplished by immersing the metal in oil or water. In the case of most copper base alloys, quenching has no effect other than to hasten cooling.

A treatment consisting of heating uniformly to a predetermined temperature and cooling rapidly in air or liquid medium to produce a desired crystalline structure.♦

Increasing the carbon content of molten cast iron or steel by adding carbonaceous material, high-carbon pig iron or a high-carbon alloy.

Carburizing a metal part to return surface carbon lost in processing.

The change from one crystal structure to another, as occurs on heating or cooling through a critical temperature.

The formation of a new, strain-free grain structure from that existing in cold worked metal, usually accomplished by heating.

A process whereby a distorted grain structure of cold worked metals is replaced by a new, stress-free grain structure as a result of annealing above a specific minimum temperature for a specific time.

Commonly, the difference, expressed as a percentage of original area, between the original cross-sectional area of a tensile test specimen and the minimum cross-sectional area measured after complete separation.

The difference, expressed as a percentage of original area, between original cross- sectional area and that after straining the specimen.

A Ladle-chemical treatment consisting of the addition of phosphorus as a work hardening agent when temper rolling black plate or sheet steel resulting in greater hardness and stiffness and with a corresponding loss in ductility.

NOTE: Black Plate in tempers T5 and T6 (R/B range 68/84) are temper rolled from Rephosphorized steel.

A cutting machine with sharpened circular blades or disc-like cutters used for trimming edges and slitting sheet and foil.

NOTE: cutter discs are also employed in producing circles from flat sheets but with differently designed machines.

A blemish caused on a casting by eruption of gas from the mold face, or by uneven mold surfaces; or occurring where the skin from a blowhole has partly burned away and is not welded.

A defect consisting of a flat volume of metal joined to a casting through a small area. It is usually set in a depression, a flat side being separated from the metal of the casting proper by a thin layer of sand.

Oxidation of metal due to heat, resulting in relatively heavy surface layers of oxide.

Removal of scale from metal.

The designation given to sheet or strip that has imperfections in moderate degree or extent, which may be classified in two general groups:

• Imperfections in the base material
• Other manufacturing defects

This term is not used in connection with non-ferrous alloys.

A thin flat hard metal strip produced to close tolerances; used primarily for tool, die and machine alignment purposes. In steel there are four general types:

• Low Carbon Rockwell B 80/100
• Hard Rolled High Carbon Rockwell C 28/33
• Hardened and Tempered Spring Steel Rockwell C 44/51
• Austenitic Stainless Steel Rockwell C 35/45

Brass shim of commercial quality is also used and most generally specified is 2 Nos. Hard but may be 4 Nos. Hard.

Si
Atomic Number: 14
Atomic Weight: 28.0855
Melting Point: 1687 K (1414°C or 2577°F)
Boiling Point: 3538 K (3265°C or 5909°F)
Density: 2.3296 grams per cubic centimeter
Phase at Room Temperature: Solid

Extremely common element, the major component of all rocks and sands; its chemical reactions, however, are those of a metalloid. Used in metallurgy as a deoxidizing scavenger. Silicon is present, to some extent, in all steels, and is deliberately added to the extent of approximately 4% for electric sheets, extensively used in alternating current magnetic circuits. Silicon cannot be electrodeposited. It is one of the principal deoxidizers with the amount used dependent on the deoxidization practice. It slightly increases the strength of ferrite without a serious loss of ductility. In larger quantities, it aids the resistance to scaling up to 500°F in air and decreases magnetic hysteretic loss.

A single solid homogeneous crystalline phase containing two or more chemical species.

A solid crystalline phase containing two or more chemical species in concentrations that may vary between limits imposed by phase equilibrium.

Heating and cooling to produce a spheroidal or globular form of carbide in steel. Spheroidizing methods frequently used are:

• Prolonged holding at a temperature just below Ae1.
• Heating and cooling alternately between temperatures that are just below Ae1.
• Heating to temperature above Ae1 or Ae3 and then cooling very slowly in the furnace or holding at a temperature just below Ae1.
• Cooling at a suitable rate from the minimum temperature at which all carbide is dissolved, to prevent the reformation of a carbide network, and then re-heating in accordance with methods 1 or 2 above. (Applicable to hypereutectoid steel containing a carbide network.

Any treatment intended to stabilize the structure of an alloy of the dimensions of a part.

Heating austenitic stainless steels that contain titanium, columbium, or tantalum to a suitable temperature below that of a full anneal in order to inactivate the maximum amount of carbon by precipitation as a carbide of titanium, columbium, or tantalum.

Transforming retained austenite in parts made from tool steel.

Precipitating a constituent from a nonferrous solid solution to improve the workability, to decrease the tendency of certain alloys to age harden at room temperature, or to obtain dimensional stability.

• 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 round mill edge carried through from the hot rolled band. Has not been slit, filed, or edge rolled. Tolerances no closer than hot-rolled strip limits.
• No. 3 Edge-Square, produced by slitting only. Not filed. Width tolerance 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.

Non-metal occurring in a number of allotropic modifications, the most common being a pale-yellow brittle solid. In steel most commonly encountered as an undesired contaminant. However, it is frequently deliberately added to cutting stock, to increase machinability.

Heating a phase to a temperature above that of a phase transformation without the transformation taking place.

Heating molten metal to a temperature to obtain more complete refining or greater fluidity.

Te
Atomic Number: 52
Atomic Weight: 127.60
Melting Point: 722.66 K (449.51°C or 841.12°F)
Boiling Point: 1261 K (988°C or 1810°F)
Density: 6.232 grams per cubic centimeter
Phase at Room Temperature: Solid

It is added to steel to modify sulfide type inclusion size, morphology and distribution. The resulting sulfide type inclusions are finer and remain ellipsoidal in shape following hot working, thereby improving transverse properties.

In heat treatment, re-heating hardened steel or hardened steel or hardened cast iron to some temperature below the eutectoid temperature for the purpose of decreasing the hardness and increasing the toughness. The process also is sometimes applied to normalized steel.

In tool steels, temper is sometimes used, but unadvisedly, to denote the carbon content.

In nonferrous alloys and in some ferrous alloys (steels that cannot be hardened by heat treatment), the hardness and strength produced by mechanical or thermal treatment, or both, and characterized by a certain structure, mechanical properties, or reduction in area during cold working.

In stainless steel strip tempers are based on a minimum tensile or yield strength. For Chromium-Nickel grades three-quarter hard temper is 175,000 T.S., 135,000 Y.S. min.

In Brass mill terminology, this temper is three B&S numbers hard or 29.4% thickness reduction.

Sn
Atomic Number: 50
Atomic Weight: 118.710
Melting Point: 505.08 K (231.93°C or 449.47°F)
Boiling Point: 2875 K (2602°C or 4715°F)
Density: 7.287 grams per cubic centimeter
Phase at Room Temperature: Solid

Soft silvery white metal of high malleability and ductility, but low tensile strength. Boiling point 4384 (degrees) F., yielding the longest molten-state range for any common metal; specific gravity 7.28. Principal use as a coating on steel in tin plate; also as a constituent in alloys.

Ti
Atomic Number: 22
Atomic Weight: 47.867
Melting Point: 1941 K (1668°C or 3034°F)
Boiling Point: 3560 K (3287°C or 5949°F)
Density: 4.5 grams per cubic centimeter
Phase at Room Temperature: Solid

Bright white metal, very malleable and ductile when exceedingly pure. Its principal functions as an alloy in the making of steel:

• Fixes carbon in inert particles
• reduces martensitic hardness and hardenability in medium chromium steels.
• prevents formation of austenite in high-chromium steels.
• prevents localized depletion of chromium in stainless steel during long heating.

Now, finding application in its own right because of its high strength and good corrosion resistance. It is added to boron steels because it combines with oxygen and nitrogen, thus increasing the effectiveness of boron. Titanium, as titanium nitride, also provides grain size control at elevated temperatures in micro alloy steels. In excess, titanium is detrimental to machinability and internal cleanness.

An arbitrarily defined temperature within the temperature range in which metal fracture characteristics determined usually by notched tests are changing rapidly such as from primarily fibrous (shear) to primarily crystalline (cleavage) fracture. Commonly used definitions are transition temperature for 50% cleavage fracture, 10-ft-lb transition temperature, and transition temperature for half maximum energy.

Sometimes also used to denote the arbitrarily defined temperature in a range in which the ductility changes rapidly with temperature.The temperature at which a change in phase occurs. The term is sometimes used to denote the limiting temperature of a transformation range. The following symbols are used for iron and steels:

• Ac (cm) In hypereutectoid steel, the temperature at which the solution of cementite in austentite is completed during heating.
• Ac1 The temperature at which austenite begins to form during heating.
• Ac3 The temperature at which transformation of ferrite to austenite is completed during heating.
• Ac4 The temperature at which austenite transforms to delta ferrite during heating.
• Ae (cm) Ae1 Ae3 Ae4 The temperatures of phase changes at equilibrium.
• Ar (cm) In hypereutectoid steel, the temperature at which precipitation of cementite starts during cooling.
• Ar1 The temperature at which transformation of austenite to ferrite or to ferrite plus cementite is completed during cooling.
• Ar3 The temperature at which austenite begins to transform to ferrite during cooling.
• Ar4 The temperature at which delta ferrite transforms to austenite during cooling.
• M(s) (or Ar) The temperature at which transformation of austenite to martensite starts during cooling.
• M(f) The temperature at which martensite formation finishes during cooling.

M(f) The temperature at which martensite formation finishes during cooling.

W
Atomic Number: 74
Atomic Weight: 183.84
Melting Point: 3695 K (3422°C or 6192°F)
Boiling Point: 5828 K (5555°C or 10031°F)
Density: 19.3 grams per cubic centimeter
Phase at Room Temperature: Solid

Gray metal of high tensile strength, ductile and malleable when specially handled. It is immune to atmospheric influences and most acids, but not to strong alkalis. The metal is used as filament and in thin sheet form in incandescent bulbs and radio tubes

• Forms hard abrasion -- resistant particles in tool steels.
• Promotes hardness and strength at elevated temperatures.

The localized increase in cross-sectional area resulting from the application of pressure during mechanical fabrication or welding.

That portion of welding cycle during which the cross-sectional area is increased by the application of pressure.

A metal working operation similar to forging.

The process of axial flow under axial compression of metal, as in forming heads on rivets by flattening the end of wire.

V
Atomic Number: 23
Atomic Weight: 50.9415
Melting Point: 2183 K (1910°C or 3470°F)
Boiling Point: 3680 K (3407°C or 6165°F)
Density: 6.0 grams per cubic centimeter
Phase at Room Temperature: Solid

Gray-white, hard metal, unaffected by atmospheric influences or alkalis but soluble in most strong acids. It cannot be electrodeposited. Its principal functions as an alloy in the making of tool steels:

• Elevates coarsening temperature of austenite (promotes fine grain).
• Increases hardenability (when dissolved)
• Resists tempering and causes marked secondary hardening.
• Inhibits grain growth during heat treating while improving strength and toughness of hardened and tempered steels.
• Additions up to .05% increase hardenability whereas larger amounts tend to reduce hardenability because of carbide formation.

Vanadium is also utilized in ferrite/pearlite micro alloy steels to increase hardness through carbonitride precipitation strengthening of the matrix.

Zn
Atomic Number: 30
Atomic Weight: 65.409
Melting Point: 692.68 K (419.53°C or 787.15°F)
Boiling Point: 1180 K (907°C or 1665°F)
Density: 7.134 grams per cubic centimeter
Phase at Room Temperature: Solid

Blue-white metal; when pure, malleable and ductile even at ordinary temperatures. Can be electrodeposited; it is extensively used as a coating for steel and sheet zinc finds many outlets, such as dry batteries, etc. Zinc-base alloys are of great importance in die casting. Its most important alloy is brass.

Zr
Atomic Number: 40
Atomic Weight: 91.224
Melting Point: 2128 K (1855°C or 3371°F)
Boiling Point: 4682 K (4409°C or 7968°F)
Density: 6.52 grams per cubic centimeter
Phase at Room Temperature: Solid

Because of its great affinity for oxygen and combines readily with nitrogen and sulfur it is used as a deoxidizer and scavenger in steel making. It is used as an alloy with nickel for cutting tools and is used in copper alloys.