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 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 – Stalls of the American Iron and Steel Institute. Common 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 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, that effects changes in structure and properties.
ALUMINIUM – (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 4116F. ; ductile and malleable; stable against normal atmospheric corrosion resistance , but attacked by both acids and alkalis. Aluminium 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 Aluminium killed) (2) Restricts grain growth (by forming dispersed oxides or nitrides) (3) Alloying element in nitriding steel.
ALUMINIUM KILLED STEEL – A steel where aluminium 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 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 manga-nese, 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.
BAINITE – A slender, needle-like (acicular) microstructure appearing in spring steel rip characterized by toughness and greater ductility than tempered Martensite. Bainite is a decomposition product of Austenite (see Austensite) 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 the 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 the 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 .70/.80 medium high carbon spring steel strip, blue-black in colour, which has been quenched in oil and drawn to desired hardness. While it looks and acts much like blue tempered spring steel and carries a Rockwell hardness of C44/47, it has not been polished and is lower in carbon content. Used for less exacting requirements than clock spring steel, such as snaps, lock springs, hold down 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 sec-tional 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 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; a oxide film blue in color produced by low temperature heating.
BORON – (chemical SymbolB) Element N. 5 of the periodic system, (atomic weight 10.82)It is gray in color, ignites at abourt 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 quantites for one purpose only-to increase the hardenability 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 materi-als, 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 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, electrics 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 indenation 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 aluminium. These gage numbers have definite relationship to each other. By this system the decimal thickness is reduced by 50% every six gage numbers-while temper is expressed by the number of B&S gage number in thickness reduc-tion, there is assigned a hardness value of ? hard. To illustrate: One number hard= ? hard, two numbers hard= ? 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.
CAMBER OR BOW – Edgewise curvature. A lateral departure of a side edge of sheet or strip metal from a straight line.
CARBIDE – A ocmpound 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 partically 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 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 cabonaceous solids, liquids or gases. The oldest method of case har-dening.
CASE – In a ferrous alloy, the outer portion that has been made harder than the inner portion, or core (see 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) – Parallel indentations or marks appearing at right angles to edge of strip forming a pattern at close and regular intervals, caused by roll vibrations.
CHEMICAL 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 colour, 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 corrision 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 paricipate 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 .90/.103 carbon range.)
COIL SET – A lengthwise curve or set found in coiled strip metals following its coil pattern. A departure from longitudinal flat-ness. Can be removed by roller or stretcher levelling from metals in the softer temper ranges.
COILS – Coiled flat sheet or strip metal-usually in one continuous piece or length.
COIL BREAKES – Creases or Ridges appearing in sheets as parallel lines transverse to the direction of rolling and generally extending across the width of the sheet.
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 QUALITY STEEL 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 – 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 hap-pens 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.
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. Hardness of an R/B 55 max. Standard hardness range R/B 55 max.
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 considerably 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, dopel 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.
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 – 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.
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 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 form 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 ex-pressed 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 – 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.
FATIGUE – The phenomenon leading to fracture under repeated or flutuating 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 “semi-finished”.
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.
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”
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 Coloured (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. Standard hardness range is/B 90 min except .070” and heavier which has a hardness of R/B 84 min.
GAGES – Manufacturers standard numbering systems indicating decimal thicknesses or diameters.
GRAIN – An individual crystal in a polycrystalline metal or alloy, including twinned regions or sub grains if present.
GRAIN DIRECTION – Refers to grain fibber 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 polycrystalline metal or alloy, usually expressed as an average when the individual sizes are fairly uniform. In metals containing two or more phases, the grain size refers to that of the matrix unless otherwise specified. Grain 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.
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. Standard hardness range of/B 70-85.
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 potion 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.
IMPACT TEST – A test for determining the behaviour 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 a single blow breaks the specimen.
IMPURITIES – Elements or compounds whose presence in a material is undesired.
INCLUSIONS – Particles of impurities (usually oxides, sulphides, 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.
KILLED STEEL – Steel deoxidised with a strong deoxidising agent, such as silicon or aluminium, to reduce the oxygen content to such a level that no reaction occurs between carbon and oxygen during solidification.
LAMINATIONS – A defect appearing in sheets or strips as 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.
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-based 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 sulphur.
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 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.
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 aluminium, 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), sulphides, 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 – 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.
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.
PASS – A single transfer of metal though 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 strss, after passing the elastic limit.
PHOSHORUS – (Chemical symbol P) – Element No. 15 of the periodic system, atomic weight 30 g. Non-metallic element occuring 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 their 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 meatal 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.
QUARTER HARD (No. 3 TEMPER) – In low carbon cols-rolled strip steel, a medium soft temper produced by a limited amount of cold rolling annealing. Standard hardness range of R/B 60-75.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.
RAGGED EDGES – Edges of Sheet or Strip, which are torn, split, cracked, ragged or burred or otherwise disfigured.
RECARBURIZING – 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 non-metallic, 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 sulphur has been added in controlled amounts after refining. The sulphur 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.
ROLLING 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.
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 approximate 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 re-melting.
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 o alloying elements, impurities or phases.
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 non-metallic constituents of a processed ore, or on the oxidized metallic constituents that are undesirable. Usually slags consist of combinations of acid 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 – (No. 4 Temper) – In low carbon-rolled stripe steel, soft and ductile. Produced by subjecting annealed Strip to a pinch pass or skin rolling (a very light rolling). Standard hardness range of R/B 65 max.
SOLERING – 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.
SPECTOGRAPH – 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.
SPEROIDIZED STRUCTURE – A microstructure consisting of a matrix containing spheroidal particles of another constituent.
SPHEROIDIZING – Heating and cooling to produce a spheroidal or globular form of carbide in steel.
SPEROIDIZING 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.
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 sulphur 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.
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.
SHEET STEEL (Low Carbon Cold Rolled) – Temper Classifications.
Temper Rockwell Full Hard (.070 & Thicker) B 84 min. Full Hard (.069 & Thinner) B 90 min.
Half Hard Approx. R/B 70/85
Quarter Hard Approx. R/B 60/75
Soft (Commercial Quality) Approx. R/B 65 max.
Drawing Quality Approx. R/B 55 max.
STRIP STEEL (Low Carbon Rolled) – Temper Classifications.
Temper Rockwell Mean Tensile#1
Full Hard (.070 & Thicker)B 84 min.80,000
#1 Full Hard (.069 & Thinner)B 90 min.80,000
#2 Half Hard B 70 – 8564,000
#3 Quarter Hard B 60 – 7054,000
#4 Skin Rolled B 65 max.48,000
#5 Dead Soft B 55 max.
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.
TEPMERED 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 colour, same is accomplished by passing through heat prepared at proper temperature depending on colour 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 of 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.
VICKERS HARDNESS – Standard method for measuring the hardness of metals, particularly those with extremely hard sur-faces; 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.
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.
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.