Metal Terminology (S)金属术语S

SAE
Abbreviation for Society of Automotive Engineers. This organization has specified¹ common and alloy² steels and copper³ base alloys⁴ in accordance with a numerical index system allowing approximation of the composition of the metal. The last two digits⁵ indicate the carbon content, usually within 0.05%.

SALT SPRAY TEST
An accelerated corrosion⁶ test in which the metal specimens⁷ are exposed to a fine mist of salt water solution either continuously or intermittently⁹.

SATIN FINISH
(See SCRATCH BRUSHED FINISH)

SCAB
(Scabby) - A blemish¹⁰ caused on a casting by eruption¹¹ of gas from the mold face or by uneven¹² mold surface or occurring where the skin from a blowhole has partly burned away and is not welded.

SCALE
(See Scaling)

SCALELESS BLUE
(See Black Oil Tempered Spring Steel)

SCALING
(1) Oxidation of metal due to heat resulting in relatively¹³ heavy surface layers of oxide¹⁴. (2) Removal of scale from metal.

SCALLOP
(See Ear)

SCALPING
Machining the surface layers from ingots, billets and slabs¹⁵ before fabrications.

SCARFING
Cutting surface areas of metal objects, ordinarily by using a gas torch. The operation permits surface defects to be cut from ingots, billets, or the edges of plate that are to be beveled for butt¹⁶ welding. (See Chipping)

SCLEROSCOPE HARDNESS (TEST)
A method for measuring the hardness of metal; a diamond-pointed hammer drops from a fixed¹⁷ distance through a tube onto the smoothed metal surface and the rebound¹⁸ distance, with a specified high-carbon steel as 100.

SCRAP¹⁹
Material unsuitable for direct use but usable for reprocessing by remelting.

SCRATCH BRUSHED FINISH
Finish obtained by mechanically brushing the surface with wire bristle²⁰ brushes, by buffing with greaseless compound or by cold rolling with wire bristled²¹ rolls of scratch etched finish.

SEAM
(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.

SEAM WELDING
An electric-resistance type of welding process, in which the lapped sheet is passed between electrodes of the roller type while a series of overlapping²² spot welds is made by the intermittent⁸ application of electric current.

SECONDS
The designation given to sheet or strip that has imperfections in moderate degree or extent, which may be classified in two general groups imperfections in the base material, or other manufacturing defects. This term is not used in connection with non-ferrous alloys.

SEGMENT STEEL
Used for laminated piston²³ rings. Carbon content about .70%. Hardened and blue tempered with round edges. Hardness usually Rockwell’s 30 N 68 to 71, width sizes vary from .058 to .163” and thickness’ are .020, .024 and .030”.

SEGREGATION
In an alloy, concentration of carbon or 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.

SELF-HARDENING STEEL
A steel containing sufficient carbon or alloying element, or both, to form martensite either through air hardening or, as in welding and induction²⁴ hardening, through rapid removal of heat from a locally heated portion by conduction into the surrounding cold metal. (See Air-Hardening Steel)

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

SEMIKILLED STEEL
Steel incompletely deoxidized, to permit evolution of sufficient carbon monoxide to offset²⁵ solidification²⁶ shrinkage.

SEMI-STEEL
Cast iron (not steel) of high quality, obtained by using a large percentage of steel scrap with the pig iron.

SHEAR²⁷
A type of cutting operation in which the metal object is cut by means of a moving blade and fixed edge or by a pair of moving blades that may be either flat or curved.

SHEAR CRACK
A diagonal, transgranular track caused by shear stresses.

SHIM
A thin flat hard metal strip produced to close tolerances²⁸; used primarily for tool, die and machine alignment²⁹ purposes. In steel there are four general types: (1) Low Carbon Rockwell B 80/100; (2) Hard Rolled High Carbon Rockwell C 28/33; (3) Hardened and Tempered Spring Steel Rockwell C 44/51; (4) Austinitic Stainless³⁰ Steel Rockwell C 35/45. Brass³¹ shim of commercial quality is also used and most generally specified as 2 Nos. Hard but may be 4 Nos. Hard.

SHORE HARDNESS TEST
(See Scleroscope Hardness)

SHORT
(See Brittleness)

SHORT TERNE
A term applying to terne coated (Lead and Tin) sheets with reference to Base Box sizes (14” x 20”). (See Terne Plate)

SHOT BLASTING
Cleaning surface of metal by air blast, using metal shot as an abrasive³³.

SHRINKAGE CAVITY
A void left in cast metals as a result of solidification shrinkage and the progressive freezing of metal towards the center.

SILICON³⁴
(Chemical Symbol Si) - Element No. 14 of the periodic system; atomic weight 28.06. Extremely common element, the major component³⁵ of all rocks and sands; its chemical reactions, however, are those of a metalloid. Used in metallurgy as a deoxidizing scavenger³⁶. Silicon is present, to some extent, in all steels, and is deliberately³⁷ added to the extent of approximately 4% for electric sheets, extensively used in alternating current magnetic circuits. Silicon cannot be electrodeposited.

SILICON STEEL
Steel usually made in the basic open-hearth³⁸ or electric furnace, with about 0.50-5.% silicon, other elements are usually kept as low as possible. Because of high electrical resistance and low hysteresis loss, silicon sheet and strip are standard in electric magnet manufacture.

SILKY FRACTURE
A steel fracture that has a very smooth fine train or silky appearance.

SILVER SOLDERS⁴⁰
Alloys of silver, copper, zinc⁴¹ and other metals, melting between 650 and 875癈. used for making strong yet moderately ductile⁴² joints⁴³ that resist corrosion.

SINGLE-ACTION PRESS
A forming press that operates with a single function, such as moving a punch into a die with no simultaneous action for holding down the clank or ejecting the formed work.

SINKER STEEL
Used for making sinkers in hosiery making machinery⁴⁴. Supplied both hardened and tempered and cold rolled and annealed. Usually extra precision rolled and extra flat. Carbon content about 1.25%.

SINKHEAD OR HOT TOP
A reservoir insulated to retain heat and to hold excess molten metal on top of an ingot mold in order to feed the shrinkage of the ingot. Also called “shrink head” or “feeder head.”

SINTERED CARBIDE
Composite, containing carbides of extremely refractory⁴⁵ metals, such as tungsten, tantalum, titanium, etc., cemented together by a relatively low-melting metal, such as cobalt acting⁴⁶ as a matrix.

SINTERING
Converting powder into a continuous mass by heating to a temperature considerably⁴⁷ below fusion⁴⁸, usually after preliminary compacting by pressure.

SKELP
A plate of steel or wrought⁴⁹ iron from which pipe or tubing is made by rolling the skelp into shape longitudinally and welding or riveting⁵⁰ the edges together.

SKIN
A thin surface layer that is different from the main mass of a metal object, in composition structure or other characteristics.

SLAB
(See Bloom)

SLAG⁵¹
A product resulting from the action of a flux⁵² on the nonmetallic constituents⁵⁵ of a processed ore, or on the oxidized metallic⁵³ constituents that are undesirable⁵⁶. Usually slags⁵⁷ consist of combinations of acid oxides with basic oxides, and neutral oxides are added to aid fusibility.

SLIT⁵⁸ EDGES
The edges of sheet or strip metal resulting from cutting to width by rotary⁵⁹ slitters.

SLITTING
Cutting sheet or strip metal to width by rotary slitters.

SLIVER
(Defect) - Loose metal piece rolled down onto the surface of the metal during the rolling operations.

SOAKING
Prolonged heating of a metal at selected temperature.

SOFT SKIN ROLLED TEMPER
(No.4 Temper) - In low carbon-rolled strip steel, soft and ductile. Produced by subjecting annealed strip to a pinch pass or skin rolling (a very light rolling).

SOLDER³⁹ EMBRITTLEMENT
Reduction in ductility⁶⁰ of a metal or alloy, associated with local penetration⁶¹ by molten solder along grain boundaries.

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

SOLUTION HEAT TREATMENT
A process in which an alloy is heated to a suitable temperature, is held at this temperature long enough to allow a certain constituent⁵⁴ to enter into solid solution and is then cooled rapidly to hold the constituent in solution. The metal is left in a supersaturated, unstable⁶² state and may subsequently exhibit age hardening.

SORBITE
Structure of steel, resulting from the tempering of martensite. In a truly sorbitic structure, the cementite is completely dispersed⁶³ in the matrix. The trend is to call this structure tempered martensite.

SORBITIC PEARLITE
Structure of steel resulting, on cooling under the proper conditions from the decomposition⁶⁴ of austenite; has a fine, Lamellar appearance.

SPACE-CENTERED
(Concerning space lattices) - Body-centered.

SPACE LATTICE
(Crystal) - A system of equivalent points formed by the intersections⁶⁵ of three sets of planes parallel to pairs of principal axes; the space lattice may be thought of as formed by the corners of the unit cells.

SPECIFIC GRAVITY
A numerical value representing the weight of a given substance as compared with the weight of an equal volume of water, for which the specific gravity is taken as 1.0000.

SPECTOGRAPH
(X-rays) - An instrument using an extended surface - a photographic plate or film, or a fluorescent⁶⁶ screen - for receiving the X-ray diffraction pattern.

SPELTER
(Prime Western Specter). A low-grade of Virgin⁶⁷ Zinc containing approximately 98% Zinc used in Galvanizing processes.

SPHEROIDIZING
Any process of prolonged heating and slow cooling of steel which will convert the carbide content into rounded or spheroid form.

SPIEGEL
High-manganese pig iron, containing 15-30% manganese, approximately 5% carbon, and less than 1% silicon, used in the manufacture of steel by the Bessemer, or basic open-hearth process.

SPINNING
The procedure of making sheet metal discs into hollow shapes by pressing the metal against a rotating form (spinning chuck) by a tool.

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 interval⁶⁸ so that fusion occurs over a small area at the interface⁶⁹ between the pieces.

SPRING-BACK
An indicator⁷⁰ of elastic⁷¹ stresses, frequently measured as the increase in diameter of a curved strip after removing it from the mandrel about which it was held. The measurement is employed as an indicator of the extent of recovery or relief of residual⁷² stresses that has been achieved by the transformation⁷³ of elastic strain to plastic strain during heating or stress relieving.

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

SPRING STEEL STRIP
Any of a number of strip steels produced for use in the manufacture of steel springs or where high tensile properties are requires marketed in the annealed state, hard rolled or as hardened and tempered strip.

SPRING TEMPER
In brass mill terminology⁷⁴, Spring Temper is eight numbers hard or 60.50% reduction.

STABILIZING⁷⁵ ANNEAL
A treatment applied⁷⁶ to austentic stainless steels that contain titanium or columbium. This treatment consists of heating to a temperature below that of a full anneal in order to precipitate⁷⁷ the maximum amount of carbon at titanium carbide or columbium carbide. This eliminates precipitation at lower temperatures, which might reduce the resistance of the steel to corrosion.

STABILIZING TREATMENT
A thermal⁷⁸ treatment designed to precipitate material from solid solution, in order to improve the workability, to decrease the tendency of certain alloys to age harden at room temperature, or to obtain dimensional stability under service at slightly elevated temperatures.

STAINLESS STEEL
Corrosion resistant⁷⁹ 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, atmospheric⁸⁰ oxidation, etc.

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

STEAM BLUED
(See Bluing)

STEEL
Iron, malleable⁸¹ 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 sulfur⁸² and phosphorus.

STICKER
Steel sheets or strip adhering. Usually by fusion spots caused by overheating during box annealing.

STRAIGHT-CHROME
An iron alloy. A term indicating a group of stainless steels the principal alloying element of which is chromium in varying amounts from 4.00 to 27.00%.

STRAIN
Deformation⁸³ produced on a body by an outside force. (See also Stress and Hooke’s Law.)

STRAIN AGING
Aging induced by cold working. (See Aging)

STRAIN HARDENING
An increase in hardness and strength caused by plastic deformation at temperatures lower than the recrystallization range.

STRESS
Deforming force to which a body is subjected or the resistance which the body offers to deformation by the force. (See also Strain and Hooke’s Law)

STRESS RELIEF
Low temperature annealing for removing internal stresses, such as those resulting in a metal from work hardening or quenching⁸⁴.

STRESS RELIEVING
Reducing residual stresses by heating.

STRETCH FORMING
A process of forming panels and cowls of large curvature by stretching sheet over a form of the desired shape. This method is more rapid than hammering and beating.

STRETCHER LEVELING
(Also termed “patent leveling.”) A method of making metal sheet or strip dead flat by stretching.

STRETCHER STRAINS
Long vein-like marks appearing on the surface of certain metals, in the direction of the maximum shear stress, when the metal is subjected to deformation beyond the yield point. Also termed Luders Lines. (Not a defect in No. 5 dead soft temper.)

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 tandem⁸⁵ cold mills in coil form from coiled hot rolled pickled strip steel.

STRUCTURE
The arrangement of parts; in crystals, especially the shape and dimension of the unit cell, and the number, kinds and positions of the atoms within it.

SULFUR
(Chemical Symbol S.) - Element No. 16 of the periodic system; atomic weight 32.06. Non-metal occurring in a number of allotropic modifications⁸⁶, the most common being a pale-yellow brittle³² solid. In steel most commonly encountered as an undesired contaminant. However, it is frequently deliberately added to cutting stock to increase machinability