Metal

A

Abrasive

A substance capable of grinding away another material.

Acid-Brittleness

Brittleness resulting from pickling steel in acid; hydrogen, formed by the interaction between iron and acid, is partially absorbed by the metal, causing acid brittleness.

 

Age Hardening

The term as applied to soft, or low carbon steels, relates to a wide variety of commercially important, slow, gradual changes that take place in properties of steels after the final treatment. These changes, which bring about a condition of increased hardness, elastic limit, and tensile strength with a consequent loss in ductility, occur during the period in which the steel is at normal temperatures.

 

Aging

Spontaneous change in the physical properties of some metals, which occurs on standing, at atmospheric temperatures after final cold working or after a final heat treatment. Frequently synonymous with the term "Age-Hardening."

 

Air Cooling

Cooling of the heated metal, intermediate in rapidity between slow furnace cooling and quenching, in which the metal is permitted to stand in the open air.

 

Air Hardening Steel

Alloy steel that may be hardened by cooling in air from a temperature above the 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.

 

AISI Steels

Steels of the American Iron and Steel Institute. Common and alloy steels have been numbered in a system essentially the same as the SAE. The AISI system is more elaborate than the SAE in that all numbers are preceded by letters: "A" represents basic open-hearth alloy steel, "B" acid Bessemer carbon steel, "C" basic open-hearth carbon steel, "CB" either acid Bessemer or basic open-hearth carbon steel, "E" electric furnace alloy steel.

 

Alloy

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

 

Alloy Steel

Steel containing significant quantities of alloying elements (other than carbon and the commonly accepted amounts of manganese, silicon, sulfur and phosphorus) added to effect changes in mechanical or physical properties. Those containing less than 5% total metallic alloying elements tend to be termed low-alloy steels, and those containing more than 5% tend to be termed high-alloy steels.

 

Alloying Element

An element added to a metal, and remaining in the metal, that effects changes in structure and properties.

 

Aluminum

(Chemical symbol Al) Element No.13 of the periodic system; Atomic weight 26.97; silvery white metal of valence 3; melting point 1220 F.; boiling point approximately 4116 F.; ductile and malleable; stable against normal atmospheric corrosion, but attacked by both acids and alkalis. Aluminum is used extensively in articles requiring lightness, corrosion resistance, electrical conductivity, etc. Its principal functions as an alloy in steel making; (1) Deoxidizes efficiently (See Aluminum killed) (2) Restricts grain growth (by forming dispersed oxides or nitrides) (3) Alloying element in nitriding steel.

 

Aluminum Killed Steel

A steel where aluminum has been used as a deoxidizing agent. (See Killed Steel.)

 

Annealing

A heating and cooling operation implying a relatively slow cooling. Annealing is a comprehensive term. The purpose of such a heat treatment may be to remove stresses; to induce softness; to alter ductility; toughness; electrical magnetic, or other physical properties; to reline the crystalline structure; to remove gases; to produce a definite microstructure. In annealing, the temperature of the operation and the rate of cooling depend upon the material being heat-treated and the purpose of the treatment.

 

Arc Welding

A group of welding processes wherein the metal or metals being joined are coalesced by heating with an arc, with or without the application of pressure and with or without the use of filler metal.

 

A.S.T.M.

Abbreviation for American Society for Testing Material - An organization for Issuing standard specifications on materials, including metals and alloys.

 

Austempering

Cooling an austenitized steel at a rate high enough to suppress formation of high-temperature transformation products, then holding the steel at a temperature below that for pearlite formation and above that for martensite formation until transformation to an essentially bainitic structure is complete.

 

Austenite

Phase in certain steels, characterized as a solid solution, usually of carbon or iron carbide, in the gamma form of iron. 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.

 

Austenitic Steel

Steel which, because of the presence of alloying elements, such as manganese, nickel, chromium, etc., shows stability of Austenite at normal temperatures.

 
B

Bainite

A slender, needle-Iike (acicular) microstructure appearing in spring steel strip characterized by toughness and greater ductility than tempered Martensite. Bainite is a decomposition product of Austenite (see Austenite) best developed at interrupted holding temperatures below those forming fine pearlite and above those giving Martensite.

Basic Oxygen Process

A steel-making process wherein oxygen of the highest purity is blown onto the surface of a bath of molten iron contained in a basic lined and ladle shaped vessel. The melting cycle duration is extremely short with quality comparable to Open Hearth Steel.

 

Basic Process

A steel-making process either Bessemer, open hearth, or electric, in which the furnace is lined with a basic refractory. A slag, rich in lime, being formed and phosphorus removed.

Bath Annealing

Is immersion in a liquid bath (such as molten lead or fused salts) held at an assigned temperature-when a lead bath is used, the process is known as lead annealing.

 

Beading

Raising a ridge on sheet metal.

 

Bend Test

Various tests used to determine the toughness and ductility of flat rolled metal sheet, strip or plate, in which the material is bent around its axis or around an outside radius. A complete test might specify such a bend to be both with and against the direction of grain. For testing, samples should be edge filed to remove burrs and any edgewise cracks resulting from slitting or shearing. If a vice is to be used then line the jaws with some soft metal or brass, so as to permit a free flow of the metal in the sample being tested.

 

Bessemer Process

A steel making process in which air Is blown through the molten iron so that the impurities are thus removed by oxidation.

Billet

A solid, semi-finished steel round or square product that has been hot worked by forging, rolling or extrusion usually smaller than a bloom.

Black Oil Tempered Spring Steel Strip

(Scaleless Blue) - A flat cold rolled usually .701.80 medium high carbon spring steel strip, blue-black in color, which has been quenched in oil and drawn to desired hardness. While it looks and acts much like blue tempered spring steel and carries a Rockwell hardness of CA4147, it has not been polished and is lower in carbon content. Used for less exacting requirements than clock spring steel, such as snaps, lock springs, hold down springs, trap springs, etc. It will take a more severe bend before fracture than will clock spring, but it does not have the same degree of spring-back.

Blast Furnace

A vertical shaft type smelting furnace in which an air blast is used, usually hot, for producing pig iron. The furnace is continuous in operation using iron ore, coke, and limestone as raw materials that are charged at the top while the molten iron and slag are collected at the bottom and are tapped out at intervals.

Blister

A defect in metal 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 "pin-head" or "pepper" blisters.

Bloom

(Slab, Billet, Sheet-Bar.) Semi-finished products, hot rolled from ingots. The chief differences are in their cross sectional areas in ratio of width to thickness, and in their intended use.

Blooming Mill

A mill used to reduce ingots to blooms, billets, slabs, sheet-bar etc., (See Semi-finished Steel).

Blowhole

A cavity produced during the solidification of metal by evolved gas, which in failing to escape is held in pockets.

Blue Tempered Spring Steel Strip

See Tempered Spring Steel Strip.

Bluing

(1) Sheets - A method of coating sheets with a thin, even film of bluish-black oxide, obtained by exposure to an atmosphere of dry steam or air, at a temperature of about 1000° F., generally this is done during box-annealing.

(2) Bluing of tempered spring steel strip; an oxide film blue in color produced by low temperature heating.

Boron

(Chemical Symbol B) Element N. 5 of the periodic system; (atomic weight 10.82.) It is gray in color, ignites at about 1112° F. and burns with a brilliant green flame, but its melting point in a non-oxidizing atmosphere is about 4000° F. Boron is used in steel in minute quantities for one purpose only - to increase the harden ability as in case hardening and to increase strength and hardness penetration.

Bow

See Camber.

Box Annealing

A process of annealing a ferrous alloy in a suitable closed metal container, with or without packing materials, in order to minimize oxidation. The charge is usually heated slowly to a temperature below the transformation range, but sometimes above or within it, and is then cooled slowly.

Brale

A diamond penetrator, conical in shape, used with a Rockwell hardness tester for hard metals.

Brazing

Joining metals by fusion of nonferrous alloys that have melting points above 800° F., but lower than those of the metals being joined. This may be accomplished by means of a torch (torch brazing), in a furnace (furnace brazing) or by dipping in a molten flux bath (dip of flux brazing).

Bright Annealing

A process of annealing usually carried out in a controlled furnace atmosphere so that surface oxidation is reduced to a minimum and the surface remains relatively bright.

Bright Basic Wire

Bright steel wire, slightly softer than Bright Bessemer Wire. Used for round head wood screws, bolts and rivets, electric welded chain, etc.

Bright Commercial Finish

Refer to FINISHES.

Brinell Hardness

(Test) - A common standard method of measuring the hardness of certain metals. The smooth surface of the metal is subjected to indentation by a hardened steel ball under pressure or load. A special microscope measures the diameter of the resultant indentation, in the metal surface,, and the Brinell hardness value is read from a chart or calculated by formula.

Brittleness

The tendency of a material to fracture without first undergoing significant plastic deformation.

Broaching

Multiple shaving, accomplished by pushing a tool with stepped cutting edges along the work, particularly through holes.

Brown & Sharpe Gages (B&S)

A standard series of sizes arbitrarily indicated, as by numbers, to which the diameter of wire or thickness of sheet metal is usually made and which is used in the manufacture of brass, bronze, cooper, copper-base alloys and aluminum. These gage numbers have a definite relationship to each other. By this system the decimal thick ness is reduced by 50% every six gage numbers - while temper is expressed by the number of B & S gage number in thickness reduction, there is assigned a hardness value of 1/4 hard. To illustrate: One number hard = 1/4 hard, two numbers hard = 1/2 hard, etc.

Buckle

Alternate bulges or hollows recurring along the length of the product with the edges remaining relatively flat.

Burning

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.

Burr

A thin ridge or roughness left by a cutting operation such as in metal slitting, shearing, blanking or sawing. This is common to a No. 3 slit edge in the case of steel.

Butt Welding

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

C

Camber or Bow

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

Carbide

A compound of carbon with one or more metallic elements.

 

Carbon

(Chemical symbol C) - Element No.6 of the periodic system; atomic weight 12.01; 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.

Carbon Range

In steel specifications, the carbon range is the difference between the minimum and maximum amount of carbon acceptable.

 

Carbon Steel

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.

 

Carburizing

(Cementation.) 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.

 

Case

In a ferrous alloy, the outer portion that has been made harder than the inner portion, or core (see case hardening).

Case 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.

Chatter Marks

(Defect) - ParalIel indentations or marks appearing at right angles to edge of strip forming a pattern at close and regular intervals, caused by roll vibrations.

 

Chemical Polishing

Improving the specular reflectivity of a metal surface by chemical treatment.

 

Chromium

(Chemical symbol Cr ) - Element No.24 of the periodic system; atomic weight 52.01. 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, (1) increases resistance to corrosion and oxidation (2) increases hardenability (3) adds some strength at high temperatures (4) resists abrasion and wear (with high carbon)

Chromium-Nickel Steel

Steel usually made by the electric furnace process in which chromium and nickel participate as alloying elements. The stainless steel of 18% chromium and 8% nickel are the better known of the chromium-nickel types.

Clad Metal

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

Clock Spring Steel

(See Tempered and Polished Spring Steel Strip .901103 carbon range.)

Coil Breaks

Creases or Ridges appearing in sheets as parallel lines transverse to the direction of rolling and generally extending across the width of the sheet.

Coil Set

A lengthwise curve or set found in coiled strip metals following its coil pattern. A departure from longitudinal flatness. Can be removed by roller or stretcher leveling from metals in the softer temper ranges.

Coils

Coiled flat sheet or strip metal-usually in one continuous piece or length.

Coining

A process of impressing images or characters of the die and punch onto a plane metal surface.

Cold Reduced Strip

Metal strip, made from hot-rolled strip, by rolling on cold-reduction mills.

Cold Reduction

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.

Cold Rolled Finish

Finish obtained by cold rolling plain pickled sheet or strip with a lubricant resulting in a relatively smooth appearance.

Commercial QualitySteel Sheet

Normally to a ladle analysis of carbon limit at 0.15 max. A Standard Quality Carbon Steel Sheet.

Continuous Casting

A casting technique in which the ingot is continuously solidified while it is being poured, and the length is not determined by mold dimensions.

Continuous Furnace

Furnace, in which the material being heated moves steadily through the furnace.

Continuous Pickling

Passing sheet or strip metal continuously through a series of pickling and washing tanks.

Controlled Atmosphere Furnaces

A furnace used for bright annealing into which specially prepared gases are introduced for the purpose of maintaining a neutral atmosphere so that no oxidizing reaction between metal and atmosphere takes place.

Corrosion

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

Corrosion Embrittlement

The embrittlement caused in certain alloys by exposure to a corrosive environment.

Crop

The defective ends of a rolled or forged product which are cut off and discarded.

Cross Break

CROSS BREAK - This term also applied to transverse ribs or ripple.

Cross 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.

Crown

Increased thickness in the center of metal sheet or strip as compared with thickness at the edge.

Crystallization

The formation of crystals by the atoms assuming definite positions in a crystal lattice. This is what happens when a liquid metal solidifies. (Fatigue, the failure of metals under repeated stresses, is sometimes falsely attributed to crystallization.)

Cyaniding

Surface hardening of an iron-base alloy article or portion of it by heating at a suitable temperature in contact with a cyanide salt, followed by quenching.

D

Dead Flat

Perfectly flat. As pertaining to sheet, strip or plate.

Dead Soft Steel

Steel, normally made in the basic open-hearth furnace or by the basic oxygen process with carbon less than 0.10% and manganese in the 0.20-0.50% range, completely annealed.

 

Dead Soft Temper

(No.5 TEMPER) - Condition of maximum softness commercially attainable in wire, strip, or sheet metal in the annealed state.

 

Deburring

A method whereby the raw slit edge of metal is removed by rolling or filing.

 

Decarburization

Loss of carbon from the surface of a ferrous alloy as a result of heating in a medium that reacts with carbon.

 

Deep Drawing

The process of cold working or drawing sheet or strip metal blanks by means of dies on a press Into shapes which are usually more or less cup-like in character involving considerable plastic deformation of the metal. Deep-drawing quality sheet or strip steel, ordered or sold on the basis of suitability for deep-drawing.

 

Degassing

Removing gases from the molten metal by means of a vacuum process in combination with mechanical action.

 

Deoxidation

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

(2) Sometimes refers to removal of undesirable elements other than oxygen by the introduction of elements or compounds that readily react with them.

 

Dish

A concave surface departing from a straight line edge to edge. Indicates transverse or across the width.

 

Drawing Back

Reheating after hardening to a temperature below the critical for the purpose of changing the hardness of the steel. (See Tempering.)

 

Drill Rod

A term given to an annealed and polished high carbon tool steel rod usually round and centerless ground. The sizes range in round stock from .013 to 1-1/2" diameter. Commercial qualities embrace water and oil hardening grades. Drill Rods are used principally by machinists and tool and die makers for punches, drills, taps, dowel pins, screw machine parts, small tools, etc.

 

Ductility

The capacity of a material to deform plastically without fracturing. Ductility is usually measured by elongation and reduction of area as determined in a tensile test.

 
E

Earing

Wavy projections formed at the open end of a cup or shell in the course of deep drawing because of differences in directional properties. Also termed scallop. See non-scalloping.

Edges

(STRIP STEELS and STAINLESS STRIP STEELS) - 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.
-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 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.

 

Edge Filing

A method whereby the raw or slit edges of strip metal are passed or drawn one or more times against a series of files, mounted at various angles. This method may be used for deburring only or filing to a specific contour including a completely rounded edge.

 

Edging

The dressing of metal strip edges by rolling, filing or drawing.

 

Elastic Limit

Maximum stress that a material will stand before permanent deformation occurs.

 

Electric Furnace Steel

Steel made in any furnace where heat is generated electrically, almost always by arc.

 

Elongation

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.

 

Embossing

Raising or indenting a design in relief on a sheet or strip of metal by passing between rolls of desired pattern.

 

Endurance Limit

ENDURANCE LIMIT - Maximum alternating stress which a given material will withstand for an indefinite number of times without causing fatigue failure.

 

Etching

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

 

Extrusion

Shaping metal into a chosen continuous form by forcing it through a die of appropriate shape.

 
F

Fatigue

The phenomenon leading to fracture under repeated or fluctuating stresses.

Ferrous

Related to iron. Ferrous alloys are, therefore, iron base alloys.

 

Filed Edges

Finished edges, the final contours of which are produced by drawing the strip over a series of small steel files.

Finished Steel

Steel that is ready for the market without further work or treatment. Blooms, billets, slabs, sheet bars, and wire rods are termed "semifinished."

 

Finishes

The surface appearance of the various metals after final treatment such as rolling, etc. Over the years the following finishes have become recognized as standard in their respective fields.

 

Finishes
(Cold Rolled Strip Steels)

-No.1 Finish-A dull finish produced without luster by rolling on roughened rolls.
-No.2 Finish-A regular bright finish produced by rolling on moderately bright rolls.
-No.3 Finish-Best Bright Finish-A lustrous or high gloss finish produced by rolling on highly polished rolls-Also referred to as "Mirror Finish."

 

Finishes
(Tempered Carbon Spring Steel Strip)

Classified by description as follows:
-(A) Black Oil Tempered.
-(B) Scaleless Tempered
-(C) Bright Tempered.
-(D) Tempered and Polished.
-(E) Tempered, Polished and Colored (Blue or straw).

Finishing Temperature

Temperature of final hot-working of a metal.

Flat Wire

A flat Cold Rolled, prepared edge section, rectangular in shape. Generally produced from hot rolled rods or specially prepared round wire by one or more cold rolling operations. May also be produced by slitting cold rolled flat metal to desired width followed by edge dressing.

 

Foil

Metal In any width but no more than about 0.005" thick.

 

Forging

Plastically deforming metal, usually hot, into desired shapes with compressive force, with or without dies.

Fracture

Surface appearance of metals when broken.

Fracture Test

Nicking and breaking a bar by means of sudden impact, to enable macroscopic study of the fractured surface.

Full Hard Temper

(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.

G

Gages

Manufacturers standard numbering systems indicating decimal thicknesses or diameters.

Grain

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

 

Grain Direction

Refers to grain fiber following the direction of rolling and parallel to edges of strip or steels.

 

Grain Growth

An increase in the average size of the grains in polycrystalline metal, usually a result of heating at elevated temperature.

 

Grain Size

A measure of the areas or volumes of grains in a polycrystalline metal or alloy, usually e> pressed as an average when the individual sizes are fairly uniform. In metals containing two or more phases, the grain size refers to that of the matrix unless otherwise specified. Grain size is reported in terms of number of grains per unit area or volume, average diameter, or as a number derived from area measurements.

 

Ground Flat Stock

Annealed and pre-ground (to close tolerances) tool steel flats in standard sizes ready for tool room use. These are three common grades; water hardening, oil hardening, and air hardening quality.

 
H

Half Hard Temper

(No.2 Temper.) In low carbon cold-rolled strip steel, produced by cold rolling to a hardness next to, but somewhat softer than full hard temper.

Hardenability

In ferrous alloys, the property that determines the depth and distribution of hardness induced by quenching.

 

Hardened and Tempered Spring Steel Strip

A medium or high carbon quality steel strip which has been subjected to the sequence of heating, quenching and tempering.

Hardening

Increasing hardness by suitable treatment, usually involving heating and cooling.

Hardness

(indentation) - Resistance of a metal to plastic deformation by indentation. Various hardness tests such as Brinell, Rockwell and Vickers may be used.

 

Heat-Affected Zone

That portion of the base metal which was not melted during brazing, cutting or welding, but within which microstructure and physical properties were altered by the treatment.

 

Heat of Steel

The product of a single melting operation in a furnace, starting with the charging of raw materials and ending with the tapping of molten metal and consequently identical in its characteristics.

 

Heat Treatment

Heating and cooling a solid metal or alloy in such a way that desired structures, conditions or properties are attained. Heating for the sole purpose of hot working is excluded from the meaning of this term.

 
I

Impact Test

A test for determining the behavior of materials when subjected to high rates of loading under conditions designed to promote fracture, usually in bending, tension or torsion. The quantity measured is the energy absorbed when the specimen is broken by a single blow.

Impurities

Elements or compounds whose presence in a material is undesired.

 

Inclusions

Particles of impurities (usually oxides, sulfides, silicates, etc.) that are held mechanically or are formed during the solidification or by subsequent reaction within the solid metal.

Indentation Hardness

The resistance of a material to indentation. This is the usual type of hardness test, in which a pointed or rounded indenter is pressed into a surface under a substantially static load.

Induction Hardening

A process of hardening a ferrous alloy by heating it above the transformation range by means of electrical induction, and then cooling as required.

 

Induction Heating

A process of heating by electrical induction.

 

Ingot

A casting suitable for hot working or re-melting.

 

Intermediate Annealing

An annealing treatment given to wrought metals following cold work hardening for the purpose of softening prior to further cold working.

 

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.

 
K

Killed Steel

Steel deoxidized with a strong deoxidizing agent, such as silicon or aluminum, to reduce the oxygen content to such a level that no reaction occurs between carbon and oxygen during solidification..

L

Laminations

A defect appearing in sheets or strips as a segregation or in layers. To become divided. caused by gas pockets in the ingot.

Ladle Analysis

A term applied to the chemical analysis representative of a heat of steel as reported by the producer. It is determined by analyzing a test ingot sample obtained during the pouring of the steel from a ladle.

 
M

Machinability

The capacity of a material to be machined easily.

Macroetching

Etching of a metal surface with the objective of accentuating gross structural details, for observation by the unaided eye or at magnifications not exceeding ten diameters.

 

Macrograph

A graphic reproduction of a prepared surface of a specimen at a magnification not exceeding ten diameters. When photographed, the reproduction is known as a photomacrograph (not a macrophotograph).

 

Malleability

The property that determines the ease of deforming a metal when the metal is subjected to rolling or hammering. The more malleable metals can be hammered or rolled into thin sheet more easily than others.

 

Manganese

(Chemical symbol Mn) - Element No 25 of the periodic system. atomic weight 54.93 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 (1) It is a 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 (2) It counteracts brittleness from sulfur.

 

Mechanical Properties

Those properties of a material that reveal the elastic and inelastic reaction when force is applied, or that involve the relationship between stress and strain, for example elasticity, tensile strength and fatigue limit. These properties have often been designated as "physical properties."

 

Mechanical Working

Plastic deformation or other physical change to which metal is subjected, by rolling, hammering, drawing, etc. to change its shape, properties or structure.

 

Melting Range

The range of temperature in which an alloy melts.

 

Metallograph

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

 

Microstructure

The structure of a prepared surface of a metal as revealed by a microscope at a magnification greater than ten diameters.

 

Mill Edge

The edge of strip, sheet or plate in the as rolled state.

 

Molybdenum

(Chemical symbol MO) - Element No. 42 of the periodic system; atomic weight 95.95. Hard, tough metal of grayish-white color, becoming very ductile and malleable when properly treated at high temperatures; melting point 4748 F.; boiling point about 6600 F specific gravity 10.2. Its principal functions as an alloy in steel making' (1) Raises grain-coarsening temperature of austenite. (2) Deepens hardening (3) Forms abrasion-resisting particles.

 
N

Nickel

(Chemical symbol Ni) - Element No. 28 of the periodic system; atomic weight 58 69 Silvery white, slightly magnetic metal, of medium hardness and high degree of ductility and malleability and resistance to chemical and atmospheric corrosion; melting point 2651 F.; boiling point about 5250 F., specific gravity 8.90.

Nitriding

Process of surface hardening certain types of steel by heating in ammonia gas at about 935-1000 F., the increase in hardness being the result of surface nitride formation. Certain alloying constituents, principal among them being aluminum, greatly facilitate the hardening reaction. In general, the depth of the case is less than with carburizing

 

Non-Ferrous Metals

Metals or alloys that are free of iron or comparatively so.

 

Non-Metallic Inclusions

Impurities (commonly oxides), sulfides, silicates or similar substances held in metals mechanically during solidification or formed by reactions in the solid state.

 

Normalizing

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.

 

Notch Brittleness

A measure of the susceptibility of a material to brittle fracture at locations of stress concentration. For example, in a notch tensile test a material is said to be "notch brittle" if its notch strength is less than its tensile strength; otherwise, it is said to be "notch ductile".

 

Nucleus

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

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

 
O

Oil-Hardening

A process of hardening a ferrous alloy of suitable composition by heating within or above the transformation range and quenching in oil.

Oil-Hardening Steel

Steel adaptable to hardening by heat treatment and quenching in oil.

 

Olsen (Ductility) Test

A method of measuring the ductility and drawing properties of strip or sheet metal which involves determination of the width and depth of impression. The test simulating a deep drawing operation is made by a standard steel ball under pressure. continuing until the cup formed from the metal sample fractures. Readings are in thousandths of an inch.

 

Ore

A mineral from which metal is (or may be) extracted.

 

Oscillate Wound

A method of even winding metal strip or wire on to a reel or mandrel wherein the strands are uniformly over-lapped. The opposite of ribbon wound.

 

Oxide

Compound of oxygen with another element.

 
P

Pass

A single transfer of metal through a stand of rolls.

Patterned or Embossed Sheet

A sheet product on which a raised or indented pattern has been impressed on either one or both surfaces by the use of rolls.

 

Pearlite

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

 

Permanent Set

Non-elastic or plastic, deformation of metal under stress, after passing the elastic limit.

 

Phosphorus

(Chemical symbol P) - Element No.15 of the periodic system; atomic weight 30gB. Non-metallic element occurring in at least three allotropic forms; melting point 111 F.; boiling point 5360 F.; specific gravity 1.82. In steels it is usually undesirable with limits set in most specifications.

 

Photomicrograph

A photographic reproduction of any object magnified more than ten diameters.

 

Physical Properties

Properties, other than mechanical properties, that pertain to the physical nature of a material; e.g.. density, electrical conductivity, thermal expansion. reflectivity, magnetic susceptibility, etc.

 

Pickling

The process of chemically removing oxides and scale from the surface of a metal by the action of water solutions of inorganic acids.

 

Pipe

Contraction cavity, essentially cone-like in shape, which occurs in the approximate center, at the top and reaching down into a casting; caused by the shrinkage of cast metal.

 

Pit

A sharp depression in the surface of the metal.

 

Plate

A flat-rolled metal product of some minimum thickness and width arbitrarily dependent on the type of metal.

 

Plating

A thin coating of metal laid on another metal.

 

Polished Surface

The finish obtained by buffing with rouge or similar fine abrasive, resulting in a high gloss or polish.

 

Pouring

The transfer of molten metal from the ladle into ingot molds or other types of molds; for example, in castings.

 

Preheating

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

 

Process Annealing

A process by which a ferrous alloy is heated to a temperature close to, but below, the lower limit of the transformation range and is subsequently cooled. This process is applied in order to soften the alloy for further cold working.

 

Pyrometer

An instrument of any of various types used for measuring temperatures.

 
Q

Quarter Hard

(No. 3 TEMPER) - In low carbon cold-rolled strip steel, a medium soft temper produced by a limited amount of cold rolling after annealing.

Quenching

In the heat treating of metals, the rapid cooling of the metal by immersing the metal in oil or water.

 

Quench Hardening

Hardening by austenitizing and then cooling at a rate such that a substantial amount of austenite is transformed to martensite.

 
R

Ragged Edges

Edges of Sheet or Strip, which are torn, split, cracked, ragged or burred or otherwise disfigured.

Recarburizing

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

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

 

Refractory

A heat-resistant material, usually nonmetallic, which is used for furnace linings and such

 

Residual Elements

Small quantities of elements unintentionally present in an alloy.

 

Resistance Welding

A type of welding process in which the work pieces are heated by the passage of an electric current through the contact. Such processes include spot welding, seam or line welding and percussion welding. Flash and butt welding are sometimes considered as resistance welding processes.

 

Resulfurized Steel

Steel to which sulfur has been added in controlled amounts after refining. The sulfur is added to improve machinability.

 

Ribbon Wound

A term applied to a common method of winding strip steel layer upon layer around an arbor or mandrel.

 

Rimmed Steel

Low-carbon steel containing sufficient iron oxide to produce continuous evolution of carbon monoxide during ingot solidification, resulting in a case or rim of metal virtually free of voids.

 

Rockwell Hardness

(TEST) - A standard method for measuring the hardness of metals. The hardness is expressed as a number related to the depth of residual penetration of a steel ball or diamond cone ("brale") after a minor load of 10 kilograms has been applied to hold the penetrator in position. This residual penetration is automatically registered on a dial when the major load is removed from the penetrator.

 

Rolled Edges

Finished edges, the final contours of which are produced by side or edging rolls. The edge contours most commonly used are square corners, rounded corners and rounded edge.

 

Rolled in Scale

A surface defect consisting of scale partially rolled into the surface of the sheet.

 

Roller Leveling

Passing sheet or strip metal through a series of staggered small rolls so as to flatten the metal.

 

Rolling

Reducing the cross-sectional area of metal stock, or otherwise shaping metal products, through the use of rotating rolls.

 

Rollin Direction

The direction, in the plane of the sheet, perpendicular to the axes of the rolls during rolling.

 

Rolling Mills

Equipment used for rolling down metal to a smaller size or to a given shape employing sets of rolls the contours of which determine or fashion the product into numerous intermediate and final shapes, e.g., blooms, slabs, rails, bars, rods, sections, plates, sheets and strip.

 
S

SAE

Abbreviation for Society of Automotive Engineers - This organization has specified common and alloy steels and copper base alloys in accordance with a numerical index system allowing approximation of the composition of the metal. The last two digits always indicate the carbon content, usually within 0.05%.

Scale

A layer of oxidation products formed on a metal at high temperature.

 

Scarfing

Cutting surface areas of metal objects, ordinarily by using a gas torch.

 

Scrap

Material unsuitable for direct use but usable for reprocessing by remelting.

 

Seam

On the surface of metal a crack that has been closed but not welded, usually produced by some defect either in casting or in working, such as blowholes that have become oxidized or folds and laps that have been formed during working. Similar to cold shut and laminations.

 

Seconds

The designation given to sheet or strip that has imperfections in moderate degree or extent.

 

Segregation

The non-uniform distribution of alloying elements, impurities or phases.

 

Semifinished Steel

SEMIFINISHED STEEL - Steel in the form of billets, blooms, etc , requiring further working before completion into finished steel ready for marketing.

 

Sheet

A flat-rolled metal product of some maximum thickness and minimum width arbitrarily dependent on the type of metal. Sheet is thinner than plate.

 

Silicon

(Chemical Symbol Si) - Element No. 14 of the periodic system; atomic weight 28.06. 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.

 

Slag

A product resulting from the action of a flux on the nonmetallic constituents of a processed ore, or on the oxidized metallic constituents that are undesirable. Usually slags consist of combinations of acid oxides with basic oxides, and neutral oxides are added to aid fusibility.

 

Slit Edges

The edges of sheet or strip metal resulting from cutting to width by rotary Slitters.

 

Slitting

Cutting sheet or strip metal to width by rotary slitters.

 

Soaking

Prolonged heating of a metal at selected temperature.

 

Soft Skin Rolled Temper

(N0. 4 Temper.) - In low carbon-rolled strip steel, soft and ductile. Produced by subjecting annealed Strip to a pinch pass or skin rolling (a very light rolling).

 

Soldering

Joining metals by fusion of alloys that have relatively low melting points - most commonly, lead-base or tin-base alloys, which are the soft solders. Hard solders are alloys that have silver, copper, or nickel bases and use of these alloys with melting points higher than 800 F. is generally termed brazing.

 

Spectrograph

An optical instrument for determining the presence or concentration of minor metallic constituents in a material by indicating the presence and intensity of specific wave lengths of radiation when the material is thermally or electrically excited.

 

Spheroidized Structure

A microstructure consisting of a matrix containing spheroidal particles of another constituent

 

Spheroidizing

Heating and cooling 10 produce a spheroidal or globular form of carbide in steel.

 

Spheroidizing Annealing

A subcritical annealing treatment intended to produce spheroidization of cementite or other carbide phases.

 

Spot Welding

An electric-resistance welding process in which the fusion is limited to a small area. The pieces being welded are pressed together between a pair of water-cooled electrodes through which an electrical current is passed during a very short interval so that fusion occurs over a small area at the interface between the pieces.

 

Spring Steel

Steel, normally of the high-carbon or alloy type, used in the manufacture of springs, lending itself to appropriate heat treatment; usually made in the open hearth or electric furnace.

 

Stainless Steel

Corrosion resistant steel of a wide variety, but always containing a high percentage of chromium. These are highly resistant to corrosion attack by organic acids, weak mineral acids, atmospheric oxidation, etc.

 

Stamping

A term used to refer to various press forming operations in coining, embossing, blanking, and pressing.

 

Steel

Iron, malleable in at least one range of temperature below its melting point without special heat treatment, substantially free from slag, and containing carbon more than about 0.05% and less than about 2.00%. Other alloying elements may be present in significant quantities, but all steels contain at least small amounts of manganese and silicon, and usually as undesirable constituents, also sulfur and phosphorus.

 

Stress

Deforming force to which a body is subjected, or, the resistance which the body offers to deformation by the force.

 

Stress Relieving

Heating to a suitable temperature, holding long enough to reduce residual stresses and then cooling slowly enough to minimize the development of new residual stresses.

 

Stretcher Leveling

A method of making metal sheet or strip dead flat by stretching.

 

Strip Steel

(Cold rolled) - A flat cold rolled steel product (Other than Flat Wire) 23-15/16" and narrower; under .250" in thickness, which has been cold reduced to desired decimal thickness and temper on single stand, single stand reversing, or tandem cold mills in coil form from coiled hot rolled pickled strip steel.

 

Sulfur

(Chemical Symbol S.) - Element No.16 of the periodic system; atomic weight 32 06. 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.

 

Surface Hardening

A generic term covering several processes applicable to a suitable ferrous alloy that produce, by quench hardening only, a surface layer that is harder or more wear resistant than the core. There is no significant alteration of the chemical composition of the surface layer. The processes commonly used are induction hardening, flame hardening and shell hardening. Use of the applicable specific process name is preferred.

 
T

Tandem Mill

Arrangement of rolling mills, in direct line, allowing the metal to pass from one set of rolls into the next.

Telescoping

Transverse slipping of successive layers of a coil so that the edge of the coil is conical rather than flat.

 

Temper

The state of or condition of a metal as to its hardness or toughness produced by either thermal treatment or heat treatment and quench or cold working or a combination of same in order to bring the metal to its specified consistency.

 

Temper Rolling

Light cold rolling of sheet steel. The operation is performed to improve flatness, to minimize the formation of stretcher strains, and to obtain a specified hardness or temper.

 

Tempered and Polished Spring Steel Strip

.90/1.03 carbon range (Also known as clock spring steel.) - This product, while similar to general description under heading of Tempered Spring Steel Strip, is manufactured and processed with great and extreme care exercised in each step of its production. Manufactured from carbon range of .90/1.03 with Rockwell range C 48/51.

 

Tempered Spring Steel Strip

Any medium or high carbon (excluding clock spring) strip steel of spring quality, which has been hardened and tempered to meet specifications. Where specification calls for blue or straw color, same is accomplished by passing through heat prepared at proper temperature depending on color required. Blue is developed at approximately 600 F.

 

Tempering

A process of re-heating quench-hardened or normalized steel to a temperature below the transformation range and then cooling at any rate desired. The primary purpose of tempering is to impart a degree of plasticity or toughness to the steel to alleviate the brittleness of its martensite.

 

Temper Rolling

Light cold rolling of sheet steel. The operation is performed to improve flatness, to minimize the formation of stretcher strains, and to obtain a specified hardness or temper.

 

Tensile Strength

Breaking strength of a material when subjected to a tensile (stretching) force Usually measured by placing a standard test piece in the jaws of a tensile machine, gradually separating the jaws, and measuring the stretching force necessary to break the test piece. Tensile strength is commonly expressed as pounds (or tons) per square inch of original cross section.

 

Thickness Gage or Feeler Stock

A hardened and tempered, edged, ground, and polished thin section, high carbon strip steel. Usually 1/2" in width and in thicknesses from .001" to .050" manufactured to extremely close tolerances. It is used primarily for determining the measurement of openings by tool and die makers, machinists, and automobile technicians.

 

Tolerance Limit

The permissible deviation from the desired value.

 

Tool Steel

Any high carbon or alloy steel capable of being suitably tempered for use in the manufacture of tools.

 

Toughness

Capacity of a metal to absorb energy and deform plastically before fracturing.

 

Trace

Extremely small quantity of an element, usually too small to determine quantitatively.

 

Tumbling

Cleaning articles by rotating them in a cylinder with cleaning materials.

 
V

Vickers Hardness

Standard method for measuring the hardness of metals, particularly those with extremely hard surfaces; the surface is subjected to a standard pressure for a standard length of time by means of a pyramid-shaped diamond. The diagonal of the resulting indention is measured under a microscope and the Vickers Hardness value read from a conversion table.

W

Water Hardening

Process of hardening high carbon steels by quenching in water or brine, after heating.

Wavy

Not flat. A slight wave following the direction of rolling and beyond the standard limitation for flatness.

 

Welding

Joining two or more pieces of material by applying heat or pressure, or both, with or without filler metal, to produce a localized union through fusion or recrystallization across the interface.

 

Work Hardening

Hardness produced by cold working.

 

Workability

The characteristic or group of characteristics that determines the ease of forming a metal into desired shapes.

 

Wrought Iron

An iron produced by direct reduction of ore or by refining molten cast iron under conditions where a pasty mass of solid iron with included stag is produced. The iron has a low carbon content.

 
Y

Yield Point

The load per unit of original cross section at which, in soft steel, a marked increase in deformation occurs without increase in load.

Gunderlin © 2008