An electric-resistance type of welding process, in which the lapped sheet is passed between electrodes of the roller type while a series of overlapping spot welds is made by the intermittent application of electric current.
(A defect.) - 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 (which see).
Finish obtained by mechanically brushing the surface with wire bristle brushes, by buffing with greaseless compound or by cold rolling with wire bristled rolls of scratch etched finish.
Material unsuitable for direct use but usable for reprocessing by remelting.
A method for measuring the hardness of metal; a diamond-pointed hammer drops from a fixed distance through a tube onto the smoothed metal surface and the rebound distance, with a specified high-carbon steel as 100.
Cutting surface areas of metal objects, ordinarily by using a gas torch. The operation permits surface defects to be cut from ingot, billets, or the edges of plate that if to be beveled for butt welding. See chipping.
Machining the surface layers from ingots, billets and slabs before fabrications.
A hardened and tempered medium high carbon spring steel strip sufficiently low hardness to take moderately sharp bends without fracture, intended for manufacture into rule dies for the purpose of cutting or stamping fabrics, paper, cardboard, plastics, and metal foil into desired shape.
(Slitting Machine) - A cutting machine with sharpened circular blades or disc-like cutters used for trimming edges and slitting sheet and foil. NOTE: cutter discs are also employed in producing circles from flat sheets but with differently designed machines.
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.
The direction, in the plane of the sheet, perpendicular to the axes of the rolls during rolling.
A term applied to the operation of shaping and reducing metal in thickness by passing it between rolls which compress, shape and lengthen it following the roll pattern.
Passing sheet or strip metal through a series of staggered small rolls so as to flatten the metal. This method is relatively ineffective in removing defects such as buckles, wavy edges, corrugations, twists, etc., or from steel in the higher hardness ranges.
A surface defect consisting of scale partially rolled into the surface of the sheet.
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.
An operation used in forming sheet. Strips of sheet are passed between rolls of definite settings that bend the sheet progressively into structural members of various contours, sometimes called "molded sections."
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. Various dial readings combined with different major loads, give "scales" designated by letters varying from "A" to "H"; the "B" and "C" scales are most commonly in use.
(Defect) - A slight transverse wave or shadow mark appearing at intervals along the piece.
Low-carbon steel in which incomplete deoxidation permits the metal to remain liquid at the top of the ingot, resulting in the formation of a bottom and side rim of considerable thickness. The rim is of somewhat purer composition than the original metal poured. If the rimming action is stopped shortly after pouring of the ingot is completed, the metal is known as capped steel. Most steels below 0.15% carbon are rimmed steels. For the same carbon and manganese content rimmed steel is softer than killed steel.
A term applied to a common method of winding strip steel layer upon layer around an arbor or mandrel.
A type of welding process on 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.
The tendency of welding process in which the work pieces are heated by the passage of an electric current through the contact. Such processed include spot welding, seam or line welding and percussion welding. Flash and butt welding are sometimes considered as resistance welding processes.
Incidental or "tramp" elements not named in a specification. These inclusions are usually due to contaminated scrap.
Macroscopic stresses that are set up within a metal as the result of non-uniform plastic deformation. This deformation may be caused by cold working or by drastic gradients of temperature from quenching or welding.
(Steel) - A Ladle-chemical treatment consisting of the addition of phosphorus as a work hardening agent when temper rolling black plate or sheet steel resulting in greater hardness and stiffness and with a corresponding loss in ductility.
A term applied to those alloys which due to hardness or abrasiveness present relative difficulty in maintaining close dimensional tolerances.
A heat-resistant material, usually nonmetallic, which is used for furnace linings and such.
An alclad product containing on one side a surface later of high-purity aluminum superimposed on a core or base alloy of commercial- purity aluminum or an aluminum-manganese alloy. The high-purity coating imparts good polishing characteristics and the core gives adequate strength and formability.
A temperature, usually just higher than the transformation range, employed in the heat treatment of steel to refine the structure in particular, the grain size.
85% Copper A copper-zinc allow containing approximately 15% zinc, used for plumbing pipe, hardware, condenser tubes. Because of its color, is used for vanity cases, coins, plaques, badges, etc. It is somewhat stronger than commercial bronze and if hardened more rapidly by cold working.
A process whereby a distorted grain structure of cold worked metals is replaced by a new, stress-free grain structure as a result of annealing above a specific minimum temperature for a specific time.
An instrument of any of various types used for measuring temperatures.
The movable part that forces the metal into the die in equipment for sheet drawing, blanking, coining, embossing and the like.
An aging process in which the temperature of the alloy is continually increased during the aging cycle. The temperature may be increased in steps or by any other progressive method. Compare with interrupted aging. ??PROPORTIONAL LIMIT The greatest stress that the material is capable of sustaining without a deviation from the law of proportionality of stress to strain. (Hooke?s Law)
In the sheet and wire industries, 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.
Metal products, such as sheet and plate, of the highest quality and free from visible surface defects.
(1) A general term used to describe heating applied as a preliminary to some further thermal or mechanical treatment. (2) A term applied specifically to tool steel to describe a process on which the steel is heated slowly and uniformly to a temperature below the hardening temperature and is then transferred to a furnace in which the temperature is substantially above the preheating temperature. (3) Nonfer. met.. Heating a metal to a relatively high temperature for a relatively long time in order to change the structure before working. Ingots are homogenized by preheating.
Nonfer met. Any of the various aging treatments conducted at elevated temperatures to improve certain of the mechanical properties through precipitation from solid solution. See artificial aging, interrupted aging, and progressive aging.
A process of hardening an alloy in which a constituent precipitates from a supersaturated solid solution. (See also Age Hardening and Aging.)
Powd met. The art of producing metal powders and of utilizing metal powders for the production of massive materials and shaped objects.
The transfer of molten metal from the ladle into ingot molds or other types of molds; for example, in castings.
A vessel for holding molten metal. Also used to refer to the electrolytic reduction cell employed in winning certain metals, such as aluminum, from a fused electrolyte.
The ability of a material to exist in more than one crystallographic structure. Numerous metals change in crystallographic structure at transformation temperatures during heating or cooling. If the change is reversible, it is allotropy. The allotropy of iron, particularly the changes between the alpha body-centered and the gamma face centered form, is of fundamental importance in the hardening of steel.
(Buffed Surface) - The finish obtained by buffing with rouge or similar fine abrasive, resulting in a high gloss or polish.
A thin coating of metal laid on another metal. Refer to Electroplating, Galvanizing, Tinning and Tinplating.
The ability of a metal to be deformed extensively without rupture.
Permanent distortion of a material under the action of applied stresses.
A method of measuring grain size, in which the grains within a definite area are counted.
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
Microscopic imperfections of the coatings, that is, microscopic bare spots, also microscopic holes penetrating through a layer or thickness of light gage metal.
Long fern like creases usually diagonal to the direction of rolling.
Iron produced by reduction of iron ore in a blast furnace. Pig iron contains approximately 92% iron and about 3.5% carbon. Balance largely silicone and manganese with small percentages of phosphorus, sulphur, and other impurities.
A defect in tin plate, galvanized or terne plated steel due to faulty pickling, leaving areas from which the oxide has not been completely removed.
The process of chemically removing oxides and scale from the surface of a metal by the action of water solutions of inorganic acids.
Those properties familiarly discussed in physics, exclusive of those described under mechanical properties; for example, density, electrical conductivity, co-efficient of thermal expansion. This term often has been used to describe mechanical properties, but this usage is not recommended. (See Mechanical Properties.)
A photographic reproduction of any object magnified more than ten diameters. The term micrograph may be used.
(Chemical symbol P) - Element No. 15 of the periodic system; atomic weight 30.98. Non-metallic element occurring in at least three allotropic forms; melting point 111?F.; boiling point 536?F.; specific gravity 1.82. In steels it is usually undesirable with limits set in most specifications. However, it is specified as an alloy in steel to prevent the sticking of light-gage sheets; to a degree it strengthens low carbon steel; increases resistance to corrosion, and improves machinability in free-cutting steels. In the manufacture of Phosphor Bronze it is used as a deoxidizing agent (which see).
A copper-base alloy containing up to 10% tin, which has been deoxidized with phosphorous in varying amounts of less than 1% (see Phosphor Bronze). Temper is imparted by cold rolling, resulting in greater tensile strength and hardness than in most copper-base alloys or either of its alloying elements copper or tin. The various tempers from "One Number Hard" to "Ten Numbers Hard" are classified in hardness by the number of B & S Gages reduction in dimension from the previous soft or as annealed state (See Brown & Sharpe Gages). Phosphor Bronze is not heat treatable for purposes of hardness
A length of pipe used to convey oxygen onto a bath of molten metal.
The addition of oxygen to a compound. Exposure to atmosphere sometimes results on oxidation of the exposed surface, hence a staining or discoloration. This effect is increased with temperature increase.
Aging under conditions of time and temperature greater than those required to obtain maximum strength.
A method of even winding metal strip or wire on to a reel or mandrel wherein the strands are uniformly overlapped. Sometimes termed "stagger wound" or "vibrated wound." The opposite of ribbon wound.
In copper base alloys industry; temper is referred to as so many numbers hard, i.e.. Yellow Brass Half Hard is termed 2 numbers hard.. This term is derived from terminology used on the mill floor whereby temper or hardness is imparted by cold working and classified as to hardness by the number of Brown & Sharpe gages away from the soft or as-annealed state.
Black Plate in tempers T5 and T6 (R/B range 68/84) are temper rolled from Rephosphorized steel.
M B, H B and extra H S designate Basic Open Hearth steels, while W M B, W H B and extra W H B designate Acid Open Hearth Steels. The chemical composition (see Analysis Page 192) and the mechanical properties are the same for both basic and acid steel.
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.
Strip steel ordered or sold on the basis of absence of uneveness, or ears, on the edges of the steel, when subjected to deep drawing.
A term opposed to refractory alloy (which see.) A non-refractory alloy has malleability, that is, ease of flattening when subjected to rolling or hammering.
Impurities (commonly oxides), sulphides, silicates or similar substances held in metals mechanically during solidification or formed by reactions in the solid state.
Metals or alloys that are free of iron or comparatively so.
Steel which is particularly suited for the nitriding process, that is, it will form a very hard and adherent surface upon proper nitriding (heating in a partially dissociated atmosphere of ammonia gas). Composition usually .20-.40 carbon, .90-1.50 chromium, .15-1.00 molybdenum, and .85-1.20% aluminum.
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.
A polished high tensile strength cold drawn wire with higher tensile strength and higher torsional strength than any other material available. These high mechanical treatment and by many continuous passes through drawing dies. The high toughness characteristic of this material is obtained by the patenting (which see). Such wire is purchased according to tensile strength, not hardness.
(A Refractory Alloy) - Alpha-beta brass, 60% copper and 40% zinc. Stronger than alpha-brass and used for castings and hot-worked (rolled, stamped, or extruded) products. High strength brasses are developed from this by adding other elements.
(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. Pure molybdenum can best be obtained as a black powder, by reduction of molybdenum trioxide or ammonium molybdate with hydrogen. From this powder, ductile sheet and wire are made by powder metallurgy techniques; these are used on radio and related work. Its principal functions as an alloy in steel making: (1) Raises grain-coarsening temperature of austenite. (2) Deepens hardening. (3)
A form of cavity onto which molten metal is poured to produce a desired shape.
Of a material suffering shear, the ratio of the intensity of the shear stress across the section to the shear strain, i.e., to the angle of distortion in radians; expressed on pounds or tons per square inch.
(Tension) - Force which would be required to stretch a substance to double its normal length, on the assumption that it would remain perfectly elastic, i.e., obey Hooke?s Law throughout the test. The ratio of stress to strain within the perfectly elastic range.
A surface finish produced on sheet and plate. Characteristic of the ground finish used on the rolls in fabrication.
The edge of strip, sheet or plate in the as rolled state. Unsheared.
The structure of polished and etched metal and alloy specimens as revealed by the microscope.
(a) Element intermediate in lustre and conductivity between the true metals and non-metals. Arsenic, antimony, boron, tellurium, and selenium, etc., are generally considered metalloids; frequently one allotropic modification off an element will be non-metallic, another metalloid in character. Obviously, no hard and fast line can be drawn. (b) In steel metallurgy, metalloid in has a specialized, even of erroneous, meaning; is covers elements commonly present in simple steel; carbon, manganese, phosphorus, silicon and sulfur.
The science concerning the constituents and structure of metals and alloys as revealed by the microscope.
A process for applying a coating of metal to an object. The metal, usually in the form of wire, is melting by an oxyhydrogen or oxyacetylene blast or by an electric arc and is projected at high speed by gas pressure against the object being coated.
The range of temperature in which an alloy melts; that is the range between solidus and liquidus temperatures.
Contains from 0.30% to 0.60% carbon and less than 1.00% manganese. May be made by any of the standard processes,
Plastic deformation or other physical change to which metal is subjected, by roiling, hammering, drawing, etc. to change its shape, properties or structure.
Any spring produced by cold forming from any material with or without subsequent heat treatment.
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, the modulus of elasticity, tensile strength and fatigue limit. These properties have often been designated as "physical properties," but the term "mechanical properties" is much to be preferred. The mechanical properties of steel are dependent on its microstructure. (See Physical Properties).
A distinctive needlelike structure existing in steel as a transition stage in the transformation of austenite, It is the hardest constituent of steel of eutectoid composition. It is produced by rapid cooling from quenching temperature and is the chief constituent of hardened carbon tool steels. Martensite is magnetic.