ASM Metals Handbook - Desk Edition (ASM_ 1998) Episode 15 pot

o redrawing o The second and successive deep-drawing operations in which cup-like shells are deepened and reduced in cross-sectional dimensions. See also deep drawing . o reducing agent o (1) A compound that causes reduction, thereby itself becoming oxidized. (2) A chemical that, at high temperatures, lowers the state of oxidation of other batch chemicals. o reducing atmosphere o (1) A furnace atmosphere that tends to remove oxygen from substances or materials placed in the furnace. (2) A chemically active protective atmosphere that at elevated temperature will reduce metal oxides to their metallic state. Reducing atmosphere is a relative term and such an atmosphere may be reducing to one oxide but not to another oxide. o reducing flame o (1) A gas flame produced with excess fuel in the inner flame. (2) A gas flame resulting from combustion of a mixture containing too much fuel or too little air. See also neutral flame and oxidizing flame . o reduction o (1) In cupping and deep drawing, a measure of the percentage decrease from blank diameter to cup diameter, or of diameter reduction in redrawing. (2) In forging, rolling, and drawing, either the ratio of the original to final cross-sectional area or the percentage decrease in cross-sectional area. (3) A reaction in which there is a decrease in valence resulting from a gain in electrons. Contrast with oxidation . o reduction cell o A pot or tank in which either a water solution of a salt or a fused salt is reduced electrolytically to form free metals or other substances. o reduction in area (RA) o The difference between the original cross-sectional area of a tensile specimen and the smallest area at or after fracture as specified for the material undergoing testing. Also known as reduction of area. o reel o (1) A spool or hub for coiling or feeding wire or strip. (2) To straighten and planish a round bar by passing it between contoured rolls. o reel breaks o Transverse breaks or ridges on successive inner laps of a coil that results from crimping of the lead end of the coil into a gripping segmented mandrel. Also called reel kinks. o reference electrodes o A nonpolarizable electrode with a known and highly reproducible potential used for potentiometric and voltammetric analyses. See also calomel electrode . o reference material o In materials characterization, a material of definite composition that closely resembles in chemical and physical nature the material with which an analyst expects to deal; used for calibration or standardization. See also standard reference material . o refining o The branch of process metallurgy dealing with the purification of crude or impure metals. Compare with extractive metallurgy . o reflowing o Melting of an electrodeposit followed by solidification. The surface has the appearance and physical characteristics of a hot dipped surface (especially tin or tin alloy plates). Also called flow brightening . o refractory o (1) A material (usually an inorganic, nonmetallic, ceramic material) of very high melting point with properties that make it suitable for such uses as furnace linings and kiln construction. (2) The quality of resisting heat. o refractory alloy o (1) A heat-resistant alloy. (2) An alloy having an extremely high melting point. See also refractory metal . (3) An alloy difficult to work at elevated temperatures. o refractory metal o A metal having an extremely high melting point and low vapor pressure; for example, niobium, tantalum, molybdenum, tungsten, and rhenium. o regenerator o Same as recuperator except that the gaseous products or combustion heat brick checkerwork in a chamber connected to the exhaust side of the furnace while the incoming air and fuel are being heated by the brick checkerwork in a second chamber, connected to the entrance side. At intervals, the gas flow is reversed so that incoming air and fuel contact hot checkerwork while that in the second chamber is being reheated by exhaust gases. o regulator o A device for controlling the delivery of welding or cutting gas at some substantially constant pressure. o reliability o A quantitative measure of the ability of a product or service to fulfill its intended function for a specified period of time. o relieving o Buffing or other abrasive treatment of the high points of an embossed metal surface to produce highlights that contrast with the finish in the recesses. o remanence o The magnetic induction remaining in a magnetic circuit after removal of the applied magnetizing force. Sometimes called remanent induction. o repressing o The application of pressure to a previously pressed and sintered powder metallurgy compact, usually for the purpose of improving some physical or mechanical property or for dimensional accuracy. o residual elements o Small quantities of elements unintentionally present in an alloy. o residual stress o (1) The stress existing in a body at rest, in equilibrium, at uniform temperature, and not subjected to external forces. Often caused by the forming or thermal processing curing process. (2) An internal stress not depending on external forces resulting from such factors as cold working, phase changes, or temperature gradients. (3) Stress present in a body that is free of external forces or thermal gradients. (4) Stress remaining in a structure or member as a result of thermal or mechanical treatment or both. Stress arises in fusion welding primarily because the weld metal contracts on cooling from the solidus to room temperature. o resilience o (1) The amount of energy per unit volume released on unloading. (2) The capacity of a material, by virtue of high yield strength and low elastic modulus, to exhibit considerable elastic recovery on release of load. o resinoid wheel o A grinding wheel bonded with a synthetic resin. o resist o (1) Coating material used to mask or protect selected areas of a substrate from the action of an etchant, solder, or plating. (2) A material applied to prevent flow of brazing filler metal into unwanted areas. o resistance brazing o A brazing process in which the heat required is obtained from the resistance to electric current flow in a circuit of which the workpiece is a part. o resistance seam welding o A resistance welding process that produces coalescence at the faying surfaces of overlapped parts progressively along a length of a joint. The weld may be made with overlapping weld nuggets, a continuous weld nugget, or by forging the joint as it is heated to the welding temperature by resistance to the flow of the welding current. o resistance soldering o A soldering process in which the heat required is obtained from the resistance to electric current flow in a circuit of which the workpiece is a part. o resistance spot welding o A resistance welding process that produces coalescence at the faying surfaces of a joint by the heat obtained from resistance to the flow of welding current through the workpieces from electrodes that serve to concentrate the welding current and pressure at the weld areas. o resistance welding o A group of welding processes that produce coalescence of metals with resistance heating and pressure. See also flash welding , projection welding , resistance seam welding , and resistance spot welding . o resistance welding electrode o The part(s) of a resistance welding machine through which the welding current and, in most cases, force are applied directly to the work. The electrode may be in the form of a rotating wheel, rotating bar, cylinder, plate, clamp, chuck, or modification thereof. o restraint o Any external mechanical force that prevents a part from moving to accommodate changes in dimension due to thermal expansion or contraction. Often applied to weldments made while clamped in a fixture. Compare with constraint . o restriking o (1) The striking of a trimmed but slightly misaligned or otherwise faulty forging with one or more blows to improve alignment, improve surface condition, maintain close tolerances, increase hardness, or effect other improvements. (2) A sizing operation in which coining or stretching is used to correct or alter profiles and to counteract distortion. (3) A salvage operation following a primary forging operation in which the parts involved are rehit in the same forging die in which the pieces were last forged. o retort o A vessel used for distillation of volatile materials, as in separation of some metals and in destructive distillation of coal. o reverberatory furnace o A furnace in which the flame used for melting the metal does not impinge on the metal surface itself, but is reflected off the walls of the root of the furnace. The metal is actually melted by the generation of heat from the walls and the roof of the furnace. o reverse-current cleaning o Electrolytic cleaning in which a current is passed between electrodes through a solution, and the part is set up as the anode. Also called anodic cleaning . o reverse drawing o Redrawing of a sheet metal part in a direction opposite to that of the original drawing. o reverse polarity o See preferred term direct current electrode positive (DCEP) . o reverse redrawing o A second drawing operation in a direction opposite to that of the original drawing. o rheocasting o Casting of a continuously stirred semisolid metal slurry. The process involves vigorous agitation of the melt during the early stages of solidification to break up solid dendrites into small spherulites. See also semisolid metal forming . o rib o A long V-shaped or radiused indentation used to strengthen large sheet metal panels. (2) A long, usually thin protuberance used to provide flexural strength to a forging (as in a rib-web forging). o rigging o The engineering design, layout, and fabrication of pattern equipment for producing castings; including a study of the casting solidification program, feeding and gating, risering, skimmers, and fitting flasks. o rimmed steel o A low-carbon steel containing sufficient iron oxide to give a continuous evolution of carbon monoxide while the ingot is solidifying, resulting in a case or rim of metal virtually free of voids. Sheet and strip products made from rimmed steel ingots have very good surface quality. o ring and circle shear o A cutting or shearing machine with two rotary-disk cutters driven in unison and equipped with a circle attachment for cutting inside circles or rings from sheet metal, where it is impossible to start the cut at the edge of the sheet. One cutter shaft is inclined to the other to provide cutting clearance so that the outside section remains flat and usable. See also circle shear and rotary shear . o ring rolling o The process of shaping weldless rings from pierced disks or shaping thick-wall ring-shaped blanks between rolls that control wall thickness, ring diameter, height, and contour. o riser o A reservoir of molten metal connected to a casting to provide additional metal to the casting, required as the result of shrinkage before and during solidification. o riser blocks o (1) Plates or pieces inserted between the top of a metalforming press bed or bolster and the die to decrease the height of the die space. (2) Spacers placed between bed and housings to increase shut height on a four-piece tie-rod straight-side press. o river pattern o A term used in fractography to describe a characteristic pattern of cleavage steps running parallel to the local direction of crack propagation on the fracture surfaces of grains that have separated by cleavage. o riveting o Joining of two or more members of a structure by means of metal rivets, the unheaded end being upset after the rivet is in place. o roasting o Heating an ore to effect some chemical change that will facilitate smelting. o robber o An extra cathode or cathode extension that reduces the current density on what would otherwise be a high-current-density area on work being electroplated. o Rochelle copper o (1) A copper electrodeposit obtained from copper cyanide plating solution to which Rochelle salt (sodium potassium tartrate) has been added for grain refinement, better anode corrosion, and cathode efficiency. (2) The solution from which a Rochelle copper electrodeposit is obtained. o rock candy fracture o A fracture that exhibits separated-grain facets; most often used to describe an intergranular fracture in a large-grained metal. o rocking shear o A type of guillotine shear that utilizes a curved blade to shear sheet metal progressively from side to side by a rocker motion. o Rockwell hardness number o A number derived from the net increase in the depth of impression as the load on an indenter is increased from a fixed minor load to a major load and then returned to the minor load. Various scales of Rockwell hardness numbers have been developed based on the hardness of the materials to be evaluated. The scales are designated by alphabetic suffixes to the hardness designation. For example, 64 HRC represents the Rockwell hardness number of 64 on the Rockwell C scale. See also Rockwell superficial hardness number . o Rockwell hardness test o An indentation hardness test using a calibrated machine that utilizes the depth of indentation, under constant load, as a measure of hardness. Either a 120° diamond cone with a slightly rounded point or a 1.6 or 3.2 mm ( or in.) diam steel ball is used as the indenter. o Rockwell superficial hardness number o Like the Rockwell hardness number, the superficial Rockwell number is expressed by the symbol HR followed by a scale designation. For example, 81 HR30N represents the Rockwell superficial hardness number of 81 on the Rockwell 30N scale. o Rockwell superficial hardness test o The same test as used to determine the Rockwell hardness number except that smaller minor and major loads are used. In Rockwell testing, the minor load is 10 kgf, and the major load is 60, 100, or 150 kgf. In superficial Rockwell testing, the minor load is 3 kgf, and major loads are 15, 30, or 45 kgf. In both tests, the indenter may be either a diamond cone or a steel ball, depending principally on the characteristics of the material being tested. o rod o A solid round metal section 9.5 mm ( in.) or greater in diameter, whose length is great in relation to its diameter. o rod mill o (1) A hot mill for rolling rod. (2) A mill for fine grinding, somewhat similar to a ball mill, but employing long steel rods instead of balls to effect grinding. o roll bending o Curving sheets, bars, and sections by means of rolls. See also bending rolls . o roll compacting o Progressive compacting of metal powders by use of a rolling mill. o roller hearth furnace o A modification of the pusher-type continuous furnace that provides for rollers in the hearth or muffle of the furnace whereby friction is greatly reduced and lightweight trays can be used repeatedly without risk of unacceptable distortion and damage to the work. See also pusher furnace . o roller leveler breaks o Obvious transverse breaks usually about 3 to 6 mm ( to in.) apart caused by the sheet metal fluting during roller leveling. These will not be removed by stretching. o roller leveler lines o Same as leveler lines . o roller leveling o Leveling by passing flat sheet metal stock through a machine having a series of small-diameter staggered rolls that are adjusted to produce repeated reverse bending. o roller stamping die o An engraved roller used for impressing designs and markings on sheet metal. o roll flattening o The flattening of metal sheets that have been rolled in packs by passing them separately through a two-high cold mill with virtually no deformation. Not to be confused with roller leveling . o roll forging o A process of shaping stock between two driven rolls that rotate in opposite directions and have one or more matching sets of grooves in the rolls; used to produce finished parts or preforms for subsequent forging operations. o roll forming o Metalforming through the use of power-driven rolls whose contour determines the shape of the product; sometimes used to denote power spinning. o rolling o The reduction of the cross-sectional area of metal stock, or the general shaping of metal products, through the use of rotating rolls. See also rolling mills . o rolling-contact fatigue o Repeated stressing of a solid surface due to rolling contact between it and another solid surface or surfaces. Continued rolling-contact fatigue of bearing or gear surfaces may result in rolling- contact damage in the form of subsurface fatigue cracks and/or material pitting and spallation. o rolling mills o Machines used to decrease the cross-sectional area of metal stock and to produce certain desired shapes as the metal passes between rotating rolls mounted in a framework comprising a basic unit called a stand. Cylindrical rolls produce flat shapes; grooved rolls produce rounds, squares, and structural shapes. See also four-high mill , Sendzimir mill , and two-high mill . o roll straightening o The straightening of metal stock of various shapes by passing it through a series of staggered rolls, the rolls usually being in horizontal and vertical planes, or by reeling in two-roll straightening machines. o roll threading o See preferred term thread rolling . o roll welding o Solid-state welding in which metals are heated, then welded together by applying pressure, with rolls, sufficient to cause deformation at the faying surfaces. See also forge welding . o root crack o A crack in either the weld or heat-affected zone at the root of a weld. o rosette o (1) Rounded configuration of microconstituents in metals arranged in whorls or radiating from a center. (2) Strain gages arranged to indicate at a single position strains in three different directions. o rotary forging o A process in which the workpiece is pressed between a flat anvil and a swiveling (rocking) die with a conical working face; the platens move toward each other during forging. Also called orbital forging. Compare with radial forging . o rotary furnace o A circular furnace constructed so that the hearth and workpieces rotate around the axis of the furnace during heating. Also called rotary hearth furnace. o rotary press o A machine for forming powder metallurgy parts that is fitted with a rotating table carrying multiple die assemblies in which powder is compacted. o rotary retort furnace o A continuous-type furnace in which the work advances by means of an internal spiral, which gives good control of the retention time within the heated chamber. o rotary shear o A sheet metal cutting machine with two rotating-disk cutters mounted on parallel shafts driven in unison. o rotary swager o A swaging machine consisting of a power-driven ring that revolves at high speed, causing rollers to engage cam surfaces and force the dies to deliver hammerlike blows on the work at high frequency. Both straight and tapered sections can be produced. o rotary swaging o A bulk forming process for reducing the cross-sectional area or otherwise changing the shape of bars, tubes, or wires by repeated radial blows with one or more pairs of opposed dies. o rouge finish o A highly reflective finish produced with rouge (finely divided, hydrated iron oxide) or other very fine abrasive, similar in appearance to the bright polish or mirror finish on sterling silver utensils. o rough blank o A blank for a metalforming or drawing operation, usually of irregular outline, with necessary stock allowance for process metal, which is trimmed after forming or drawing to the desired size. o rough grinding o Grinding without regard to finish, usually to be followed by a subsequent operation. o roughing stand o The first stand (or several stands) of rolls through which a reheated billet passes in front of the finishing stands. See also rolling mills and stand . o rough machining o Machining without regard to finish, usually to be followed by a subsequent operation. o roughness o (1) Relatively finely spaced surface irregularities, the heights, widths, and directions of which establish the predominant surface pattern. (2) The microscopic peak-to-valley distances of surface protuberances and depressions. See also surface roughness . o rubber forming o Forming a sheet metal wherein rubber or another resilient material is used as a functional die part. Processes in which rubber is employed only to contain the hydraulic fluid are not classified as rubber forming. o rubber-pad forming o A sheet metal forming operation for shallow parts in which a confined, pliable rubber pad attached to the press slide (ram) is forced by hydraulic pressure to become a mating die for a punch or group of punches placed on the press bed or baseplate. Also known as the Guerin process . Variations of the Guerin process include the fluid-cell process , fluid forming , and Marforming process . o rubber wheel o A grinding wheel made with a rubber bond. o runner o (1) A channel through which molten metal flows from one receptacle to another. (2) The portion of the gate assembly of a casting that connects the sprue with the gate(s). (3) Parts of patterns and finished castings corresponding to the portion of the gate assembly described in (2). o runner box o A distribution box that divides molten metal into several streams before it enters the casting mold cavity. o runout o (1) The unintentional escape of molten metal from a mold, crucible, or furnace. (2) An imperfection in a casting caused by the escape of metal from the mold. o rupture stress o The stress at failure. Also known as breaking stress or fracture stress . o rust o A visible corrosion product consisting of hydrated oxides of iron. Applied only to ferrous alloys. See also white rust . o S o sacrificial protection o Reduction of corrosion of a metal in an electrolyte by galvanically coupling it to a more anodic metal; a form of cathodic protection. o saddling o Forming a seamless metal ring by forging a pierced disk over a mandrel (or saddle). o sag o An increase or decrease in the section thickness of a casting caused by insufficient strength of the mold sand of the cope or of the core. o salt bath heat treatment o Heat treatment for metals carried out in a bath of molten salt. o salt fog test o An accelerated corrosion test in which specimens are exposed to a fine mist of a solution usually containing sodium chloride, but sometimes modified with other chemicals. Also known as salt spray test. o salt spray test o See salt fog test . o sample o (1) One or more units of a product (or a relatively small quantity of a bulk material) withdrawn from a lot or process stream and then tested or inspected to provide information about the properties, dimensions, or other quality characteristics of the lot or process stream. (2) A portion of a material intended to be representative of the whole. o sand o A granular material naturally or artificially produced by the disintegration or crushing of rocks or mineral deposits. In casting, the term denotes an aggregate, with an individual particle (grain) size of 0.06 to 2 mm (0.002 to 0.08 in.) in diameter, that is largely free of finer constituents, such as silt and clay, which are often present in natural sand deposits. The most commonly used foundry sand is silica; however, zircon, olivine, aluminum silicates, and other crushed ceramics are used for special applications. o sandblasting o Abrasive blasting with sand. See also blasting or blast cleaning and compare with shotblasting . o sand casting o Metal castings produced in sand molds. o sand hole o A pit in the surface of a sand casting resulting from a deposit of loose sand on the surface of the mold. o sandwich rolling o Rolling two or more strips of metal in a pack, sometimes to form a roll-welded composite. o satin finish o A diffusely reflecting surface finish on metals, lustrous but not mirrorlike. One type is a butler finish. o saw gumming o In saw manufacture, grinding away of punch marks or milling marks in the gullets (spaces between the teeth) and, in some cases, simultaneous sharpening of the teeth; in reconditioning of worn saws, restoration of the original gullet size and shape. o sawing o Using a toothed blade or disk to sever parts or cut contours. o scab o A defect on the surface of a casting that appears as a rough, slightly raised surface blemish, crusted over by a thin porous layer of metal, under which is a honeycomb or cavity that usually contains a layer of sand; defect common to thin-wall portions of the casting or around hot areas of the mold. o scale o Surface oxidation, consisting of partially adherent layers of corrosion products, left on metals by heating or casting in air or in other oxidizing atmospheres. o scale pit o (1) A surface depression formed on a forging due to scale remaining in the dies during the forging operation. (2) A pit in the ground in which scale (such as that carried off by cooling water from rolling mills) is allowed to settle out as one step in the treatment of effluent waste water. o scaling o (1) Forming a thick layer of oxidation products on metals at high temperature. Scaling should be distinguished from rusting, which involves the formation of hydrated oxides. See also rust . (2) Depositing water-insoluble constituents on a metal surface, as in cooling tubes and water boilers. o scalping o Removing surface layers from an ingot, billet, or slab. o scanning Auger microscopy (SAM) o An analytical technique that measures the lateral distribution of elements on the surface of a material by recording the intensity of their Auger electrons versus the position of the electron beam. o scarfing o Cutting surface areas of metal objects, ordinarily by using an oxyfuel gas torch. The operation permits surface imperfections to be cut from ingots, billets, or the edges of plate that are to be beveled for butt welding. See also chipping . o Scleroscope hardness number (HSc or HSd) o A number related to the height of rebound of a diamond-tipped hammer dropped on the material being tested. It is measured on a scale determined by dividing into 100 units the average rebound of the hammer from a quenched (to maximum hardness) and untempered AISI W-5 tool steel test block. o Scleroscope hardness test o A dynamic indentation hardness test using a calibrated instrument that drops a diamond-tipped hammer from a fixed height onto the surface of the material being tested. The height of rebound of the hammer is a measure of the hardness of the material. o scorification o Oxidation, in the presence of fluxes, of molten lead containing precious metals, to partly remove the lead in order to concentrate the precious metals. o scoring o (1) The formation of severe scratches in the direction of sliding. (2) The act of producing a scratch or narrow groove in a surface by causing a sharp instrument to move along that surface. (3) The marring or scratching of any formed metal part by metal pickup on the punch or die. (4) The reduction in thickness of a material along a line to weaken it intentionally along that line. o scouring o (1) A wet or dry cleaning process involving mechanical scrubbing. (2) A wet or dry mechanical finishing operation, using fine abrasive and low pressure, carried out by hand or with a cloth or wire wheel to produce satin or butler-type finishes. o scrap o (1) Products that are discarded because they are defective or otherwise unsuitable for sale. (2) Discarded metallic material, from whatever source, that may be reclaimed through melting and refining. o scratch hardness o The hardness of a metal determined by the width of a scratch made by drawing a cutting point across the surface under a given pressure. o screen o (1) The woven wire or fabric cloth, having square openings, used in a sieve for retaining particles greater than the particular mesh size. U.S. standard, ISO, or Tyler screen sizes are commonly used. (2) One of a set of sieves, designated by the size of the openings, used to classify granular aggregates such as sand, ore, or coke by particle size. (3) A perforated sheet placed in the gating system of a mold to separate impurities from the molten metal. o screw dislocation o See dislocation . o screw press o A high-speed press in which the ram is activated by a large screw assembly powered by a drive mechanism. o scuffing o (1) Localized damage caused by the occurrence of solid-phase welding between sliding surfaces, without local surface melting. (2) A mild degree of galling that results from the welding of asperities due to frictional heat. The welded asperities break, causing surface degradation. o seal coat o Material applied to infiltrate the pores of a thermal spray deposit. o sealing o (1) Closing pores in anodic coatings to render them less absorbent. (2) Plugging leaks in a casting by introducing thermosetting plastics into porous areas and subsequently setting the plastic with heat. o seal weld o Any weld designed primarily to provide a specific degree of tightness against leakage. o seam o (1) On a metal surface, an unwelded fold or lap that appears as a crack, usually resulting from a discontinuity. (2) A surface defect on a casting related to but of lesser degree than a cold shut . (3) A ridge on the surface of a casting caused by a crack in the mold face. o seam weld o A continuous weld made between or upon overlapping members, in which coalescence may start and occur on the faying surfaces, or may have proceeded from the outer surface of one member. The continuous weld may consist of a single weld bead or a series of overlapping spot welds. o seam welding o See arc seam weld and resistance seam welding . o season cracking o An obsolete historical term usually applied to stress-corrosion cracking of brass. o secondary alloy o Any alloy whose major constituent is obtained from recycled scrap metal. o secondary creep o See creep. o secondary ion mass spectroscopy (SIMS) o An analytical technique that measures the masses of ions emitted from the surface of a material when exposed to a beam of incident ions. The incident ions are usually monoenergetic and are all of the same species, for example, 5 keV Ne + ions. o secondary metal o Metal recovered from scrap by remelting and refining. o sectioning o The removal of a conveniently sized, representative specimen from a larger sample for metallographic inspection. Sectioning methods include shearing, sawing (using hacksaws, band saws, and diamond wire saws), abrasive cutting, and electrical discharge machining. o segment die o A die made of parts that can be separated for ready removal of the workpiece. Synonymous with split die . o segregation o (1) Nonuniform distribution of alloying elements, impurities, or microphases in metals and alloys. (2) A casting defect involving a concentration of alloying elements at specific regions, usually as a result of the primary crystallization of one phase with the subsequent concentration of other elements in the remaining liquid. Microsegregation refers to normal segregation on a microscopic scale in which material richer in an alloying element freezes in successive layers on the dendrites (coring) and in constituent network. Macrosegregation refers to gross differences in concentration (for example, from one area of a casting to another). See also inverse segregation and normal segregation . o segregation banding o Inhomogeneous distribution of alloying elements aligned in filaments or plates parallel to the direction of working. o seizing [...]... of a cold- or hot-rolling mill See also rolling mills standard electrode potential o The reversible potential for an electrode process when all products and reactions are at unit activity on a scale in which the potential for the standard hydrogen half-cell is zero o standard gold o standard reference material o o o A type of drop hammer in which the ram is raised for each stroke by a double-action... produced by solid-state reduction of iron oxide (mill scale or iron ore) spot drilling o o spotfacing o o Making an initial indentation in a work surface, with a drill, to serve as a centering guide in a subsequent machining process Using a rotary, hole-piloted end-facing tool to produce a flat surface normal to the axis of rotation of the tool on or slightly below the workpiece surface spot weld o A weld... fastened; sometimes called the ram The inner slide of a double-action press is called the plunger or punch-holder slide; the outer slide is called the blankholder slide The third slide of a triple-action press is called the lower slide, and the slide of a hydraulic press is often called the platen slime o o A type of fracture in metals, typical of plane-stress fractures, in which the plane of separation is... are reciprocal time strain-rate sensitivity (m-value) o o where is the true stress, is the true strain, and K, which is called the strength coefficient, is equal to the true stress at a true strain of 1.0 The strain-hardening exponent, also called "nvalue," is equal to the slope of the true stress/true strain curve up to maximum load, when plotted on log-log coordinates The n-value relates to the ability... KIc Plane-strain fracture toughness The minimum value of Kc for any given material and condition KId Dynamic fracture toughness The fracture toughness determined under dynamic loading conditions; it is used as an approximation of KIc for very tough materials KIscc Threshold stress-intensity factor for stress-corrosion cracking The critical plane-strain stress intensity at the onset of stress-corrosion... holding long enough to reduce residual stresses, and then cooling slowly enough to minimize the development of new residual stresses o stress-rupture strength o stress-rupture test o o See creep-rupture strength See creep-rupture test o stress state o stress-strain curve o o o The leveling of a piece of sheet metal (that is, removing warp and distortion) by gripping it at both ends and subjecting... at some time during the cooling cycle time-temperature curve o A curve produced by plotting time against temperature o time-temperature-transformation (TTT) diagram o tinning o o o A polymorphic modification of tin that causes it to crumble into a powder known as gray tin It is generally accepted that the maximum rate of transformation occurs at about -4 0 °C (-4 0 °F), but transformation can occur at... stress This excludes corrosion-reduced sections that fail by fast fracture It also excludes intercrystalline or transcrystalline corrosion, which can disintegrate an alloy without applied or residual stress Stress-corrosion cracking may occur in combination with hydrogen embrittlement stress-intensity factor o A scaling factor, usually denoted by the symbol K, used in linear-elastic fracture mechanics... the factor is called the critical stress-intensity factor, or the fracture toughness Various subscripts are used to denote different loading conditions or fracture toughnesses: Kc Plane-stress fracture toughness The value of stress intensity at which crack propagation becomes rapid in sections thinner than those in which plane-strain conditions prevail KI Stress-intensity factor for a loading condition... heating only certain portions of a workpiece selective leaching o o See Ugine-Sejournet process Quenching only certain portions of an object self-diffusion o Thermally activated movement of an atom to a new site in a crystal of its own species, as, for example, a copper atom within a crystal of copper o self-hardening steel o self-lubricating material o o o Preliminary operations performed prior to finishing . o redrawing o The second and successive deep-drawing operations in which cup-like shells are deepened and reduced in cross-sectional dimensions. See also deep drawing . o reducing. space. (2) Spacers placed between bed and housings to increase shut height on a four-piece tie-rod straight-side press. o river pattern o A term used in fractography to describe a characteristic. a high-current-density area on work being electroplated. o Rochelle copper o (1) A copper electrodeposit obtained from copper cyanide plating solution to which Rochelle salt (sodium potassium