17-4 PH - A chromium-nickel grade of stainless steel that has excellent mechanical properties at a high strength and hardness level. Scaling and distortion are minimal. Both the strength and corrosion resistance hold up well in temperatures to 800°F, but material is magnetic.
18-8 - 300 series stainless steel having approximately (not exactly) 18% chromium and 8% nickel. The term "18-8" is used interchangeably to characterize fittings made of 302, 302HQ, 303, 304, 305, 384, XM7, and other variables of these grades with close chemical compositions. There is little overall difference in corrosion resistance among the "18-8" types, but slight differences in chemical composition do make certain grades more resistant than others against particular chemicals or atmospheres. "18-8" has superior corrosion resistance to 400 series stainless, is generally nonmagnetic, and is hardenable only by cold working.
Active - The surface has lost its ability to resist corrosion (the passive state) under the prevailing conditions
Advanced High Strength Steels (AHSS) - Newly developed steels known for their increased strength, lightweight composition, improved performance under impact and energy transfer when exposed to a collision. There are two primary types of AHSS, Dual Phase (DP) and Transformation Induced Plasticity (TRIP). Although the two steel types differ in the material composition, each features increased tensile strength and formability than in traditional steel products. AHSS steels have a tensile strength may start at 400 MPa (58 ksi). See High strength stainless steels, Ultimate High Strength Steels (UHSS)
Age hardening - Martensitic stainless steels are hardened by heating above their critical temperature, holding them at heat to insure uniform temperature, and cooling them rapidly by quenching in air or oil.
Aging - A change in the properties of certain metal and alloys (such as steel) that occurs at ambient or moderately elevated temperatures after a hot working heat treatment or cold working operation. Typical properties impacted are: hardness, yield strength, tensile strength, ductility, impact value, formability, magnetic properties, etc.
AISI (American Iron and Steel Institute) - A North American trade association. These companies represent the United States, Canada, and Mexico in all aspects of the steel industry.
Alloy - A metal composed of a combination of two or more metals or a combination of a metal and a non-metal. Alloys are created to produce advantages that the pure metals cannot offer on their own.
Alloy steel - An iron-based mixture is considered to be an alloy steel when manganese is greater than 1.65%, silicon over 0.5%, copper above 0.6%, or other minimum quantities of alloying elements such as chromium, nickel, molybdenum, or tungsten are present. An enormous variety of distinct properties can be created for the steel by substituting these elements in the recipe.
Alloy steels - Alloy steels have enhanced properties due to the presence of one or more special elements, or to the presence of larger proportions of elements such as manganese and silicon than are present in carbon steels.
Alloy surcharge - The producer’s selling price plus a surcharge added to offset the increasing costs of raw materials caused by increasing alloy prices.
Alloying element - Any metallic element added during the melting of steel or aluminum for the purpose of increasing corrosion resistance, hardness, or strength. The metals used most commonly as alloying elements in stainless steel include chromium, nickel, and molybdenum.
Aluminum killed steel (Special killed) - Steel deoxidized with aluminum in order to reduce the oxygen content to a minimum so that no reaction occurs between carbon and oxygen during solidification.
AN - An acronym for Air Force-Navy.
Anneal - A heat treatment to fully soften the material and/or to dissolve and take back into equilibrium solution any intermetallic compounds (e.g. carbides) which may have formed within the crystal structure. For most metals and alloys this involves heating to a specified high temperature and subsequently cooling at a slow rate. However, for austenitic stainless steels the subsequent cooling must be rapidly effected.
Annealing - Annealing is a thermal process whereby the material is heated to and maintained at a suitable temperature, followed by cooling to ambient conditions when the metal now has a stable structure.
Annealing (Solution Annealing) - A process of heating cold stainless steel to obtain maximum softness and ductility by heat treatment which also produces a homogeneous structure (in austenitic grades) or a 50/50 mixture of austenite and ferrite (in duplex grades). It relieves stresses that have built up during cold working and insures maximum corrosion resistance. Annealing can produce scale on the surface that must be removed by pickling.
Anodic protection - Polarization to a more oxidizing potential to achieve a reduced corrosion rate by the promotion of passivity.
ANSI - American National Standards Institute. ANSI was formerly the ASA American Standards Association
Apparent supply - Derived demand for steel using AISI reported steel mill shipments plus Census Bureau reported imports, less Census Bureau reported exports. Domestic market share percentages are based on this figure, which does not take into account any changes in inventory.
Arc cutting - The process when an arc is utilized in metal cutting for use between an electrode and the metal that is being cut.
Argon-Oxygen Decarburization (AOD) - A process of further reducing the carbon content of stainless steel during refinement. AOD is closely related to Electric Arc Furnaces (EAF), but has a shorter operating time and requires lower temperatures. The amount of carbon in stainless steel must be lower than that in carbon steel or lower alloy steel (i.e., steel with alloying element content below 5%). While electric arc furnaces (EAF) are the conventional means of melting and refining stainless steel, AOD is an economical supplement, as operating time is shorter and temperatures are lower than in EAF steelmaking.
ASME - An acronym for the American Society of Mechanical Engineers. ASME is a not-for-profit professional organization that promotes the art, science and practice of mechanical and multidisciplinary engineering and allied sciences throughout the world.
ASTM - American Society of Testing and Materials. See ASTM International
ASTM International (ASTM), - Originally known as the American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. The organization's headquarters is in West Conshohocken, Pennsylvania, about 5 miles northwest of Philadelphia.
Austenite - A phase in the steel with the smallest building block of atomic structure of “face centered cubic” (fcc) i.e. one atom at the eight corners of a cube and one in the center of each of the six faces. Austenitic stainless steels with this structure include 1.4301 (Type 304 stainless steel) and are characteristically non-magnetic.
Austenitic - The largest category of stainless steel, accounting for about 70% of all production. The austenitic class offers the most resistance to corrosion in the stainless group, owing to its substantial nickel content and higher levels of chromium. Austenitic stainless steels are hardened and strengthened through cold working (changing the structure and shape of steel by applying stress at low temperature) instead of by heat treatment. Ductility (ability to change shape without fracture) is exceptional for the austenitic stainless steels. Excellent weldability and superior performance in very low-temperature services are additional features of this class. Applications include cooking utensils, food processing equipment, exterior architecture, equipment for the chemical industry, truck trailers, and kitchen sinks. The two most common grades are type 304 (the most widely specified stainless steel, providing corrosion resistance in numerous standard services) and type 316 (similar to 304, with molybdenum added, to increase opposition to various forms of deterioration).
Austenitic stainless steel - Non-magnetic stainless steels that contain nickel and chromium sufficient to develop and retain the austenitic phase at room temperature. Austenitic stainless steels are the most widely used category of stainless steel.
Austenitizing - The first stage during the hardening / strengthening heat treatment of martensitic stainless steels. Normally followed by a tempering treatment after cooling down to ambient temperatures.
Auto stamping plant - A facility that presses a steel blank into the desired form of a car door or hood, for example, with a powerful die (pattern). The steel used must be ductile (malleable) enough to bend into shape without breaking.
Automatic gauge control - Using hydraulic roll force systems, steelmakers have the ability to control precisely their steel sheet’s gauge (thickness) while it is traveling at more than 50 miles per hour through the cold mill. Using feedback or feed-forward systems, a computer’s gap sensor adjusts the distance between the reduction rolls of the mill 50-60 times per second. These adjustments prevent the processing of any off-gauge steel sheet.top
Baghouse - An air pollutant control device used to trap particles by filtering gas streams through large cloth or fiberglass bags.
Bake hardenable steel - A cold-rolled, low-carbon sheet steel used for automotive body panel applications. Because of special processing, the steel has good stamping and strength characteristics, and, after paint is baked on, improved dent resistance.
Bales -Term associated with banded lifts of pipe
Bar - A finished steel product, commonly in flat, square, round or hexagonal shapes. Rolled from billets, bars are produced in two major types, merchant and special.
Bar turning - Involves machining a metal bar into a smaller diameter.
Barlow's formula - An equation which shows the relationship of internal pressure to allowable stress, nominal thickness and diameter
Bars - Long steel products that are rolled from billets. Merchant bar and reinforcing bar (rebar) are two common categories of bars, where merchants include rounds, flats, angles, squares, and channels that are used by fabricators to manufacture a wide variety of products such as furniture, stair railings, and farm equipment. Rebar is used to strengthen concrete in highways, bridges, and buildings.
Basic Oxygen Furnace (BOF) - A pear-shaped furnace, lined with refractory bricks, which refines molten iron from the blast furnace and scrap into steel. Up to 30% of the charge into the BOF can be scrap, with hot metal accounting for the rest.
Beam - Long pieces of squared-off metal, normally stainless steel, which are used in building construction.
Bend tests - Tests used to assess the ductility and malleability of stainless steel subjected to bending.
Bending - The forming of metals into various angles.
Bevel - The angle formed between the prepared edge of the end of the pipe and a plane perpendicular to the surface of the member. The standard bevel for line pipe is 30o to facilitate welding
Billet - A solid semi-finished round or square product that has been hot worked by forging, rolling or extrusion. For seamless tubular products, the billet is heated and pierced to form a tube hollow. A billet is different from a slab because of its outer dimensions; billets are normally two to seven inches square, while slabs are 30 inches to 80 inches wide and two inches to ten inches thick
Binary alloy - An alloy created by combining two materials. The two constituents can be two metals or one metal and one non-metal.
Binder - The boring agent in ceramic slurry or sand.
BL - Break Load, meaning the weight at which a product will break. Typically, Suncor products have a minimum 4:1 safety factor.
Black bare - Term associated with pipe surface whereby the pipe will not be coated with mill spray oil and grease spots and cutting oil will not be removed.
Black dry - Term associated with pipe surface whereby the pipe will not only be coated with mill spray oil and all grease spots and cutting oil will be removed by washing.
Black oiled - Term associated with pipe surface whereby material ordered in this manner is protected with a varnish type oil on the O.D. for temporary corrosion protection during transit and in short term storage.
Black pipe - Denotes lacquered OD finish (as opposed to bare or galvanized)
Black plate - Cold-reduced sheet steel, 12 inches to 32 inches wide, that serves as the substrate (raw material) to be coated in the tin mill.
Blank - A section of sheet stainless steel that has the outer dimensions of a specific part but has not yet been stamped by the end user. Steel sheet of high dimensional precision, in simple or complex form, sometimes multi-thickness, principally used in automobile body parts.
Blanking - An early step in preparing flat-rolled steel for use by an end user. A blank is a section of sheet that has the same outer dimensions as a specified part (such as a car door or hood), but that has not yet been stamped. Steel processors may offer blanking for their customers to reduce their labor and transportation costs; excess steel can be trimmed prior to shipment.
Blast furnace - A towering cylinder lined with heat-resistant (refractory) bricks, used by integrated steel mills to smelt iron from iron ore. A blast furnace’s name comes from the “blast” of hot air and gases forced up through the iron ore, coke, and limestone that load the furnace.
Bloom - A semi-finished steel form, with a rectangular cross-section that is more than 8”. This large cast steel shape is broken down in the mill to produce the familiar I-beams, H-beams, and sheet piling. Blooms are also part of the high quality bar manufacturing process: Reduction of a bloom to a much smaller cross-section can improve the quality of the metal.
Blooming mill - A hot rolling mill that takes continuously cast slabs or ingots and processes them into blooms.
Brazing - Brazing and soldering are techniques for joining metals in the solid state by means of a fusible filler metal with a melting point well below that of the base metal.
Breakout - An accident caused by the failure of the walls of the hearth of the blast furnace, resulting in liquid iron or slag (or both) flowing uncontrolled out of the blast furnace.
Bright annealing - An annealing process done in a protective atmosphere to prevent surface tarnish or oxidation. A cracked ammonia gas is usually used during bright annealing of strip (coil) at the steel mill. The resulting finish is 2R (BSEN 10088-2), often also known as BA.
Brinell - Hardness testing system which measures indentation of the subject using a standard weight, shaped point. See Rockwell, Vickers.
Brittle fracture - A fracture that has little or no plastic deformation.
Brownfield expansion - A “Brownfield” contrasts to a “Greenfield” (or a facility new from the ground up). A Brownfield expansion means adding on to an existing facility.
Build-up sequence - Occurs when weld beads are deposited in a certain order.
Burr - A subtle ridge on the edge of strip stainless steel resulting from cutting operations such as slitting, trimming, shearing, or blanking. For example, as a stainless steel processor trims the sides of the sheet stainless steel parallel or cuts a sheet of stainless steel into strips, its edges will bend with the direction of the cut. See Edge rolling
Burst test - A destructive hydraulic test employed to determine actual yield strength and ultimate strength of both seamless and welded pipe.
Busheling - Scrap consisting of sheet clips and stampings from metal production. This term arose from the practice of collecting the material in bushel baskets through World War II.
Butt-weld pipe - The standard pipe used in plumbing. Heated skelp is passed continuously through welding rolls, which form the tube and squeeze the hot edges together to make a solid weld.
Camber - Camber is the deviation of a side edge from a straight edge. Measurement is taken by placing a straight edge on the concave side of a sheet and measuring the distance between the sheet edge and the straight edge in the center of the arc. Camber is caused by one side being elongated more than the other. The hook or dogleg near the ends of a coil.
Camber tolerances - Camber is the deviation from edge straightness. Maximum allowable tolerance of this deviation of a side edge from a straight line is defined in ASTM Standards.
Capacity - Normal ability to produce metals in a given time period. This rating should include maintenance requirements, but because such service is scheduled to match the needs of the machinery (not those of the calendar), a mill might run at more than 100% of capacity one month and then fall well below rated capacity as maintenance is performed.
Carbide - A compound formed when an element combines with carbon. The carbides of metals are usually intensely hard.
Carbide precipitation - Chemical reaction whereby the intermetallic carbides are formed within the crystal structure. They are hard particles that impart hardness and abrasion resisting properties. However, in stainless steels heating to within a high temperature range (±450°-850°C) causes the formation chromium carbide. This takes place preferentially at the grain boundaries. A small amount of carbon locks up a large amount of chromium. The material is thus “sensitized”. The chromium depleted grain boundaries are therefore prone to suffer preferential and accelerated corrosive attack along the grain boundaries (intergranular corrosion).
Carbon steel - Steel that has properties made up mostly of the element carbon and which relies on the carbon content for structure. Most of the steel produced in the world is carbon steel. Carbon steel contains only 2% carbon and other incidental elements. Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, columbium [niobium], molybdenum, nickel, titanium, tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 per cent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60. The term carbon steel may also be used in reference to steel which is not stainless steel; in this use carbon steel may include alloy steels.
Case hardening - Hardening a ferrous alloy to make the outside (case) much harder than the inside (core). This can be done carburizing, cyaniding, nitriding, carbonitriding, induction hardening, and flame hardening. Their application to stainless steel is limited wherever they decrease corrosion resistance.
Casing - Casing is the structural retainer for the walls of oil and gas wells, and accounts for 75% (by weight) of OCTG shipments. Casing is used to prevent contamination of both the surrounding water table and the well itself. Casing lasts the life of a well and is not usually removed when a well is closed.
Casting - The production an object of a certain shape by pouring molten metal into a mold to produce an ingot or a continuously cast slab.
Casting shrinkage - Reducing the volume of liquid metal as the cooling process takes place before the liquid hardens.
Castrip - Process to directly cast molten steel into a final shape and thickness without additional hot or cold rolling. This reduces capital investment, energy, and environmental cost.
Cathodic corrosion - Corrosion caused by a reaction of an amphoteric metal with the alkaline products of electrolysis.
Cathodic inhibitor - A chemical substance that prevents or slows a cathodic or reduction reaction.
Cathodic protection - Methods of increasing the corrosion resistance of the surface, over a wider range of conditions, for example on Type 316 stainless steel in some seawater applications. Impressed voltage methods are widely used, lowering the electrode potential of the metal surface.
Cavitation - The rapid formation and depletion of air bubbles that can damage the material at the solid/liquid interface under conditions of severe turbulent flow.
Cavitation damage - The wearing of a metal due to the collapse and formation of cavities in a liquid.
Centerless grinding - An operation whereby the surface of a bar is ground without using a lathe.
Chamfer - A beveled surface to eliminate an otherwise sharp corner.
Chamfering - Eliminating a sharp corner by machining an angle.
Chaplet - Supporting a core by inserting a mold cavity.
Charge - The material that is loaded into an electric furnace that will melt into a composition that will produce a stainless molten product. Normally recycled scrap, iron, and alloying elements.
Charpy Impact Test - Invented by Georges Augustin Albert Charpy (1865-1945). The Charpy test measures the energy absorbed by a standard notched specimen while breaking under an impact load. The Charpy impact test continues to be used as an economical quality control method to determine the notch sensitivity and impact toughness of engineering materials. The Charpy Test is commonly used on metals, but is also applied to composites, ceramics and polymers. With the Charpy test one most commonly evaluates the relative toughness of a material, as such, it is used as a quick and economical quality control device. See Brinell, Rockwell, and Vickers
Chemical analysis - A report of the chemical composition of the elements, and their percentage that form a stainless steel product.
Chemical properties - Normally associated with a limited number of chemical elements; however, depending upon the specification, practically a full analysis may be required. Minimum or maximum limits are established in Standards.
Chemistries - The chemical composition of steel indicating the amount of carbon, manganese, sulfur, phosphorous and a host of other elements.
Chloride stress corrosion cracking - Cracking due to the combination of tensile stress and corrosion in the presence of water and chlorides.
Chlorides (halides) - Ions formed from chlorine (fluorine, bromine, iodine) atoms. Often corrosive when in solutions. Can be the cause of localized attack mechanisms such as crevice, pitting and stress corrosion cracking.
Chromium (Cr) - Chromium is a hard, malleable, glossy, gray, chemical element with an atomic weight of 24. Chromium has no odor or taste. It is used in alloys to bestow corrosion resistance and shine. Chromium has the remarkable ability to form a film on the surface of stainless steel and continually repair itself, even in an oxidative environment.
Cladding - Application of a stainless steel coating to lower-alloy steel by means of pouring, welding, or coating to increase corrosion resistance at a lower cost than using steel exclusively.
Coal - The primary fuel used by integrated iron and steel producers.
Coated steels -Steel is coated by a hot process or through electrolysis with a layer of a substance that protects the metal base against corrosion. The most commonly used coating material is zinc that can be applied either using a hot process (hot-dip galvanizing) or using electrolysis (electro-galvanizing). An organic coating (paint, plastic) can also be deposited on the zinc layer.
Coating - The process of covering steel with another material (tin, chrome, and zinc), primarily for corrosion resistance.
Coil - A finished steel product such as sheet or strip that has been wound or coiled after rolling.
Coils - Metal sheet that has been wound. The metal, once rolled flat, is more than one-quarter mile long; coils are the most efficient way to store and transport sheet steel.
Coke - Coke is the basic fuel consumed in blast furnaces in the smelting of iron. Coke is a processed form of coal. About 1,000 pounds of coke are needed to process a ton of pig iron, an amount that represents more than 50% of an integrated steel mill’s total energy use.
Coke oven battery - A set of ovens that process coal into coke. Coke ovens are constructed in batteries of ten to 100 ovens that are 20 feet tall, 40 feet long, and less than two feet wide. Coke batteries, because of the exhaust fumes emitted when coke is pushed from the ovens, often are the dirtiest area of a steel mill complex.
Cold drawing - The process is effected without the metal being first heated to high temperatures. Examples of the process are the drawing of a tube through a die and over a mandrel to reduce its OD and/ or wall thickness, or drawing wire through successive dies in series to reduce its diameter.
Cold drawn - Tubing, or possibly pipe, that is pulled through a die to reduce diameter and wall. This process usually produces closer tolerances and higher strength.
Cold finished bars - Hot rolled stainless steel bars that are annealed and cold worked to produce a higher surface quality and higher strength.
Cold forming (Cold working) - Any mechanical operation that creates permanent deformation, such as bending, rolling, drawing, etc. performed at room temperature that increases the hardness and strength of the stainless steel.
Cold reduction - Process of rolling cold coils of pickled hot-rolled sheet through a cold reduction mill to make the stainless steel stronger, thinner, and smoother by applying pressure.
Cold rolling - The passing of sheet or strip that has previously been hot-rolled and pickled through cold rolls, i.e. below the softening temperature of the metal. Cold rolling makes a product that is thinner, smoother, and stronger than can be made by hot rolling alone.
Cold rolling mill - Equipment that reduces the thickness of flat steel products by rolling the metal between alloy steel cylinders at ambient temperature.
Cold work - Deforming metal plastically at a temperature lower than the recrystallization temperature. Mechanical or hydraulic expansion employed to achieve higher mechanical properties.
Cold working - Deformation (forming, machining) below the recrystallization temperature of the steel, resulting in a progressive increase in strength and hardness as more working is done. Changes in the structure and shape of steel achieved through rolling, hammering, or stretching the steel at a low temperature (often room temperature) to create a permanent increase in the hardness and strength of the steel.
Cold-rolled strip (Sheet) - Sheet steel that has been pickled and run through a cold-reduction mill. Cold-rolled sheet is considerably thinner and stronger than hot-rolled sheet, so it will sell for a premium. see Sheet steel
Columbium (Cb) - Also referred to as niobium, is a grey, ductile, tarnish-resistant and superconductive metal with a melting point of 2468°C. The name niobium (Nb) was officially adopted in 1951 by the International Union of Pure and Applied Chemistry, after 100 years of controversy. In North America many metallurgists and metal dealers still refer to the metal as columbium. Columbium is an important alloy in high-strength, low-alloy (HSLA) steels. High-purity columbium products are used in superalloys for the aerospace industry and in superconductor magnets for powerful generators.
Complex-phase (CP) Steels - CP steels are characterized by a very fine microstructure of ferrite and a higher volume fraction of hard phases (martensite and bainite), strengthened further by fine carbon or nitrogen precipitates of niobium, titanium, or vanadium. These steel grades have been used for parts that require high energy-absorption capacity, such as bumpers and B-pillar reinforcements.
Conduit - Pipe serving as a duct for electrical wiring.
Consumption - The physical use of stainless steel by end users. Consumption predicts changes in inventories, unlike demand figures.
Continuous casting - Processes of pouring stainless steel directly from the furnace into a billet, bloom, or slab. This process avoids the need for large, expensive mills and also saves time because the slabs solidify in minutes rather than the several hours it takes for an ingot to form.
Continuous weld - In common usage, a phrase for continuous butt weld. A furnace welded pipe produced in continuous lengths from coiled skelp and subsequently cut into individual lengths, having its longitudinal butt joint forge welded by the mechanical pressure developed in rolling the hot formed skelp through a series of round pass welding rolls.
Contract sales - Metal products committed to customers through price agreements extending three to 12 months. About one-half of all flat-rolled steel is sold on this basis, primarily because the auto companies sign agreements to cover at least one year’s model. Price increases that the steel mills might announce during the year do not generally affect the revenues from the contract side of the business.
Conventional High-strength Steels - The transition from mild steel to HSS occurs at a yield strength of about 210 megapascals (MPa) [30 kilopounds per square inch (KSI)]. For yield strength levels below 280 to 350 MPa (40 to 50 KSI), a simple carbon-manganese (CMn) steel typically is used.
Conversion cost - Resources spent to process material in a single stage, from one type to another. The costs of converting iron ore to hot metal or bauxite to aluminum can be isolated for analysis.
Converter/Processor - Processes steel into a more finished state, such as pipe, tubing, and cold-rolled strip, before selling it to end-users.
COREX® - A coal-based smelting process that yields hot metal or pig iron. The output can be used by integrated mills or EAF mills.
Corrosion - An electrochemical process where metal atoms are removed from the surface of the steel. Stainless steels have good general corrosion resistance but can suffer from localized corrosion mechanism such as crevice, pitting and stress corrosion cracking. Stainless steel has a passive film created by the presence of chromium (and often other alloying elements, nickel, molybdenum) that resists this process.
Corrosion fatigue - Cracking due to repeating and fluctuating stresses in a corrosive environment.
Corrosion potential - The potential of a corroding surface in an electrolyte relative to a reference electrode under open-circuit conditions.
Corrosion rate - The rate at which an object corrodes. See corrosion.
Corrosion resistance - A metal's ability to resist corrosion in a particular environment.
CRAP - An abbreviation for "cold rolled annealed and pickled."
Creep - The slow and continuous deformation of a metal at high temperatures, above 1112° F. The deformation (strain) is dependent on the stress, the temperature and time. At the high temperatures creep can occur at very low levels of stress. The deformation (strain) is dependent on the stress, the temperature and time. At the high temperatures creep can occur at very low levels of stress.
Crevice corrosion - Corrosion of stainless steel on the surface that is fully shielded from air such that the passive film cannot be created to resist the corrosion.
Critical pitting potential - The lowest value of oxidizing potential at which pits can form and grow. The value depends on the test method used.
Crude steel - Steel in the first solid state after melting, suitable for further processing or for sale. Synonymous to raw steel.
Cut-to-length - Process to uncoil sections of flat-rolled stainless steel and cut them into a desired length. Product that is cut to length is normally shipped flat-stacked.
CW - Continuous Weld a method of producing small diameter pipe (1/2 - 4") or tube.
CWT - Hundred Weight. Often used in handling or trucking pricing, i.e. .30/cwt load out charge or $1.65/cwt (freight) with a minimum such as 30,000#.top
Deburring - The process used to smooth the sharp, jagged edges of a cut piece of steel.
Deep drawing - A cold forming the manufacturing process of forming sheet metal stock, called blanks, into geometrical or irregular shapes that are more than half their diameters in depth. Deep drawing involves stretching the metal blank around a plug and then moving it into a molding cutter called a die. Common shapes for deep drawn products include cylinders for aluminum cans and cups for baking pans. Irregular items, such as enclosure covers for truck oil filters and fire extinguishers, are also commonly manufactured by the deep drawing method. Grade 1.4301(Type 304) is used widely for deep drawn saucepans.
Deep drawing applications - Parts/applications that require deep drawing in their fabrication. Examples are motor shells, fenders, quarter panels, and door panels.
Deformation - A change in the shape or size of an object due to an applied force.
Descaling - A process that removes the oxide scale from the surface of the stainless steel that develops from hot operations.
Desulfurization - An operation that injects a chemical mixture into a ladle full of hot metal to remove sulfur prior to its charging into the Basic Oxygen Furnace.
Die stamping - Permanent marking placed on pipe as required by some specifications.
Differences - Electrogalvanizing equipment is more expensive to build and to operate than hot dipped, but it gives the steelmaker more precise control over the weight of the zinc coating. The automotive manufacturers, because they need the superior welding, forming, and painting ability of electrogalvanized steel, purchase 90% of all tonnage produced.
Direct Reduced Iron (DRI) - Processed iron ore that is iron-rich enough to be used as a scrap substitute in electric furnace steelmaking. DRI is only economically feasible in regions where natural gas is attractively priced.
Double extra - Standard pipe weight designation (XXS). Sometimes described as XXH (double extra heavy).
Drawing (Drawn) - A forming process that presses metal into or through a die (as in cold drawn wire).
Drawn-over-mandrel - A procedure for producing specialty tubing using a drawbench to pull tubing through a die and over a mandrel, giving excellent control over the inside diameter and wall thickness. Advantages of this technique are its inside and outside surface quality and gauge tolerance. Major markets for materials produced by this process include automotive applications and hydraulic cylinders.
Drift - Minimum ID clearance verified by pulling a mandrel of known size through a length of pipe
Drill pipe - Pipe used in the drilling of an oil or gas well. Drill pipe is the conduit between the wellhead motor and the drill bit. Drilling mud is pumped down the center of the pipe during drilling, to lubricate the drill bit and transmit the drilled core to the surface. Because of the high stress, torque and temperature associated with well drilling, drill pipe is a seamless product.
DSAW - Double Submerged Arc Weld.
Ductility - The property of a metal to deform in a plastic manner (i.e. undergo permanent strain) without fracturing. Elongation and reduction of area (RA) are reported properties that give an indication of the ductility. A metal that is ductile can be shaped without cracking.
Duplex stainless (DP) - A category of stainless steel with high amounts of chromium and moderate nickel content. The duplex class is so named because it is a mixture of austenitic (chromium-nickel stainless class) and ferritic (plain chromium stainless category) structures. This combination was originated to offer more strength than either of those stainless steels. Duplex stainless steels provide high resistance to stress corrosion cracking (formation of cracks caused by a combination of corrosion and stress) and are suitable for heat exchangers, desalination plants, and marine applications.top
Edge rolling (Edge conditioning) - Rolling a strip of steel to smooth the edges. By removing the burr off the coil, it is safer for customers to use and manipulate. See deburring
Elastic springback - When stainless steel is bent, the metal towards the outside of the bend is in tension and the metal towards the inside is in compression. If the applied bending force is not sufficient to cause permanent plastic flow at either the inner or outer surfaces, the metal will return elastically to its original shape. Stainless steel has a greater elastic springback than mild steel.
Electric Arc Furnace (EAF) - A stainless steel producing furnace where scrap generally makes up a high percentage, and often up to 100%, of the charge. Heat is supplied from electricity that arcs from the electrodes to the metal bath. These furnaces may operate on AC or DC. Furnaces may be either an alternating current (AC) or direct current (DC). DC units consume less energy and fewer electrodes, but they are more expensive.
Electric resistance welded (ERW) Pipe - Pipe made from strips of hot-rolled steel that are passed through forming rolls and welded. Seamless pipe is traditionally stronger and more expensive than comparable ERW pipe, but ERW technology is improving and the technique now accounts for approximately 48% of OCTG shipments by tonnage.
Electrical steel - Also called lamination steel, silicon electrical steel, silicon steel or transformer steel, is specialty steel tailored to produce certain magnetic properties, such as a small hysteresis area (small energy dissipation per cycle, or low core loss) and high permeability.
Electrogalvanized - Zinc plating process whereby the molecules on the positively charged zinc anode attach to the negatively charged sheet steel. The thickness of the zinc coating is readily controlled. By increasing the electric charge or slowing the speed of the steel through the plating area, the coating will thicken.
Electrolytic galvanized - Cold Rolled or Black Plate to which a coating of zinc is applied by electro-deposition; used for applications in which corrosion resistance and paintability is a primary concern.
Electrolytic tin coated sheets (ETCS) - Cold rolled sheets coated with tin by electro-deposition through an acid or alkaline process.
Electrolytic tin plate (ETP) - Light-gauge, low-carbon, cold reduced steel on which tin has been electrodeposited. Black plate coated with Tin (Sn) electron deposition.
Electropolishing - A process whereby the metal surface is actually corroded away under very carefully controlled electrolytic conditions. A smoothing and leveling of the surface takes place. Burrs are also removed from any rough edges. The surface of electropolished stainless steel has a high degree of reflectivity, and the passive film produced on the surface is superior (more corrosion resistant) owing to the formation of oxygen gas at the surface during the process.
Elongation - A measurement of ductility expressed in terms of the stretch having occurred over a given length on a standard tensile specimen at time of fracture, usually based upon an original length of 2 inches.
Embrittlement - A material's loss of malleability due to chemical treatment or physical change.
EMI - Electromagnetic inspection a method of determining wall thickness and detecting imperfections in steel tubes
Engineered capacity - The theoretical volume of a mill or smelter, given its constraints of raw material supply and normal working speed.
Erosion - The continuous depletion of a material due to mechanical interaction with a liquid, a multi-component fluid, or solid particles carried with the fluid.
Erosion-Corrosion - An accelerated loss of material concerning corrosion and erosion that results from corrosive material interacting with the material.
ERW - Electric Resistance Weld. See High Frequency Welding
EUE - External upset ends forging of ends on (API) tubing and drill pipe to provide additional thickness for strengthening connections
EW - Electric Weld. See High Frequency Weld
Exotic Alloys - Zirconium, niobium, hafnium, and tantalum products.
Expanded pipe / Expanded tube - Pipe or tube that has been enlarged circumferentially by mechanical or hydraulic pressure.
Extra strong - Standard pipe weight designation (XS). Sometimes described as XH (extra heavy).
Extrusion - The process of shaping material by forcing it to flow through a shaped opening in a die.top
Fabricate - To work a material into a finished state by machining, forming, or joining.
Fabricator - An intermediate product producer that purchases materials and processes them specifically for a particular project. For example, a rebar (see Reinforcing bar) fabricator purchases rebar and processes the material to the specifications of a particular construction project.
Fastmet - A process to directly reduce iron ore to metallic iron pellets that can be fed into an electric arc furnace with an equal amount of scrap. This process is designed to bypass the coke oven-blast furnace route to produce hot metal from iron ore. It is also one of several methods that mini-mills might use to reduce their dependence on high-quality scrap inputs (see Direct Reduced Iron and Hot Briquetted Iron).
Fatigue - If metals are subjected to repeated fluctuating (reversing) loads at stresses below the tensile strength, a fatigue crack can initiate in the material which, with increasing number of loading cycles, propagates through the material until final failure by fracture of the metal remaining occurs. Fatigue is an interrelationship between stress and the number of load cycles, the lower the stress the greater the number of cycles that can be tolerated (in some metals a stress below a certain limiting stress value will never induce fatigue). Failure by fatigue is very sensitive to any surface defects or imperfections that radically lower the fatigue resistance.
Fatigue (endurance) - A progressive mechanical failure mechanism resulting from oscillating (cyclic) stresses (e.g. vibration) over a large number of stress reversals. Martensitic steels can be susceptible to fatigue, other types are more resistant.
Feedstock - Any raw material. Substrate.
Ferrite - A phase in the steel with the smallest building block of atomic structure of 'body centered cubic' (bcc) i.e. one atom at the eight corners of a cube and one in the center of the cube. Ferritic stainless steels with this structure include 1.4016 (Type 430) and are characteristically magnetic.
Ferritic - Magnetic stainless steels that have a low carbon content and contain chromium as the main alloying element, usually between 13% and 17%. It is the second most widely used stainless steel. Ferritic stainless steels are generally used in automotive trim and exhaust systems, hot water tanks, and interior architectural trim.
Ferritic stainless steels - Are plain chromium steels with no significant nickel content; the lack of nickel results in lower corrosion resistance than the austenitics (chromium-nickel stainless steels). Ferritics are best suited for general and high-temperature corrosion applications rather than services requiring high strength. They are used in automotive trim and exhaust systems, interior architectural trim, and hot water tanks. Two of the most common grades are Type 430 (general-purpose grade for many applications, including decorative ones) and Type 409 (low-cost grade well suited to withstanding high temperatures).
Ferroalloy - Metal products such as ferrochrome, ferromanganese, and ferrosilicon that are commonly used as raw materials to aid various stages in stainless steel making.
Ferrochrome - A common raw material in stainless steel production. This alloy consists of iron and up to 72% chromium. Ferrochrome is commonly used as a raw material in the making of stainless steel.
Ferrous - Any metal that is primarily composed of iron.
Finish - The final condition of the surface after the last phase of production. The surface appearance of steel after final treatment.
Finishing facilities - These facilities process semi-finished stainless steel (slabs or billets) into ready-made forms that can be used by others. Some facilities are rolling mills, pickle lines, tandem mills, annealing facilities, and temper mills.
Finishing stand - The last stand in a rolling mill, which determines the surface finish and final gauge.
Finmet - The process reduces iron ore fines with gas in a descending series of fluidized bed reactors. The reduced iron is hot briquetted.
Flat products - Types of rolled products that have smooth surfaces and are available in a range of dimensions and a variety of thicknesses. The two major flat steel product categories are thin flat products (between 1 mm and 10 mm in thickness) and plates (between 10 mm and 200 mm in thickness and used for large welded pipes, shipbuilding, construction, major works and boilers).
Flat-Rolled Stainless Steel (Flat Product) - Category of stainless steel that includes shapes such as sheet, strip, and plate.
Flat-rolled steel - Category of steel that includes sheet, strip, and tin plate, among others. Produced by passing ingot/slab through pairs of rolls.
Flattening test - A quality test for pipe in which a specimen is flattened between parallel plates that are closed to a specified height.
FLD - Full Length Drift (as opposed to "end drift") usually performed as part of used tubing or casing (OCTG) inspection
Flush joint - Connection with male and female threads cut directly into the pipe (as opposed to T&C). This provides the same ID and OD clearance as in the middle of the tube, once lengths are joined.
Flux - An iron cleaning agent. Limestone and lime react with impurities within the metallic pool to form a slag that floats to the top of the relatively heavier (and now more pure) liquid iron.
FOB pricing - Free on Board Pricing. This phrase that explains whether the transportation costs of the steel are included. “FOB Mill” is the price of steel at the mill, not including shipping.
Foil - Metal with a maximum width of .005 inches.
Forging - Forming a hot or cold metal into a predetermined fixed shape by hammering, upsetting, rolling or pressing.
Forming - Bending and forming plate or sheet products into customer specified shapes and sizes with press brakes. A process that brings about a change in the shape of stainless steel by the application of force (i.e. cold forming, hot forming, wire forming).
Free machining - A stainless steel to which a small amount of some relatively insoluble element (such as sulfur, selenium) is added to create a minute and widely distributed soft phase that acts as chip breakers during machining.
Free machining grades - Brought about the addition of sulphur or selenium, increases cutting speeds by approximately 75% on stainless steel. Sulphur is preferred for heavy machining because of the large and fairly continuous inclusions. Selenium is better for light work where a good finish is required.
Freight equalization - A common industry practice when a mill sells steel outside its geographic area; it will assume any extra shipping costs (relative to the competition) to quote the customer an equivalent price to get the business.
Fretting corrosion - Deterioration at the interface of two contacting surfaces under load that is accelerated by their relative motion.
Full hard cold rolled - Hot rolled pickled steel that is cold reduced to a specified thickness and subject to no further processing (not annealed or temper rolled). The product is very stiff; it is not intended for flat work where deformation is very minimal.
Full hard temper - Full Hard Cold Rolled steel produced to a Rockwell hardness of 84 and higher on the B scale.top
Galfan - A galvanized product coated with 95% free zinc, 5% aluminum and traces of mish metal in the coating; provides extra corrosion protection with lighter coating weight; has improved formability over regular free zinc coatings (hot dipped galvanized regular products).
Galvalume® - Steel sheet with a unique coating of 55% aluminum and 45% zinc that resists corrosion. The coating is applied in a continuous hot-dipped process, which improves the steel’s weather resistance. Galvalume® is a trademark of BHP Steel, and the product is popular in the metal building market.
Galvaneal coating - Coatings on hot-dipped galvanized steels processed to convert the coating completely to zinc-iron alloys; dull gray in appearance, have no spangle, and after proper preparation, are well suited for painting.
Galvanic corrosion - An accelerated degree of corrosion occurring when two different metals are in contact with moisture, particularly sea water. All metals have what is termed a specific electric potential, so that low level electric current flows from one metal to another. A metal with a higher position in the galvanic series (see below) will corrode sacrificially rather than one with a lower position, meaning stainless, for example, will corrode before gold. The further apart the metals on the chart, the more electric current will flow and the more corrosion will occur.
Galvanize coatings - Free zinc coatings applied to a hot-rolled or cold-rolled steel to produce Galvanized steel. The coating can be applied by the hot-dip or electrodeposition process.
Galvanized steel - Steel coated with a thin layer of zinc to provide corrosion resistance in underbody auto parts, garbage cans, storage tanks, or fencing wire. Sheet steel normally must be cold-rolled prior to the galvanizing stage.
Galvanizing - Covering of iron or steel surfaces with a protective layer of zinc (weight defined in specifications).
Galvannealed - An extra tight coat of galvanizing metal (zinc) applied to a soft steel sheet, after which the sheet is passed through an oven at about 1200 degrees F. The resulting coat is dull gray without spangle especially suited for subsequent painting.
Gauer bar - A term meaning Edged Flat Bar. see edge rolling
Gauge - The thickness of sheet steel. Better-quality steel has a consistent gauge to prevent weak spots or deformation.
General corrosion - "General corrosion" is the term used to describe the attack that proceeds in a relatively uniform manner over the entire surface of a metal. Typically stainless steels do not exhibit general corrosion.
GigaJoule - A measure of energy. A GigaJoule equals 1,000,000,000 Joules. A 100-watt light bulb turned on for one second consumes 100 Joules.
Grain (Grain boundary) - The individual crystal units comprising the aggregate structure where the crystalline orientation does not change. The grain boundary is where these individual crystal units meet.
Grain-oriented - The metal’s grain runs parallel within the steel, permitting easy magnetization along the length of the steel. Although grain-oriented steel may be twice as expensive to produce, its magnetic directional characteristics enable power transformers, made from this metal, to absorb less energy during operation. See non-grain oriented
Greenfield facility - New metal making complex that is built “from scratch,” presumably on a green field. See Brownfield
Grinding - A term that implies metal removal similar to fast milling where the surface is removed by abrasion. Involves grinding the top and/or bottom of carbon or alloy steel plate or bars into close tolerance.
Gross Ton - 2,240 pounds.top
Hafnium - An exotic alloy usually obtained as a by-product of zirconium production with outstanding corrosion resistance and good mechanical properties. It is added to specialty alloys for use in jet engine parts and as control rod material in nuclear reactors.
Hardenable - This means that a material can be hardened by heat treatment which involves heating the material to a specified high temperature and subsequently cooling it (quenching) at a rapid rate. Quenching must be followed by tempering in order to develop the correct required combination of strength, hardness, ductility and toughness.
Hardening - A process that increases the hardness of steel, i.e., the degree to which steel will resist cutting, abrasion, penetration, bending, and stretching. Hardening can be achieved through various methods, including 1) heat treatment, where the properties of steel are altered by subjecting the steel to a series of temperature changes; and 2) cold working, in which changes in the structure and shape of steel are achieved through rolling, hammering, or stretching the steel at a relatively low temperature.
Hardfacing - Abrasion resistant metal applied by welding (usually in strips) on the surface of softer material to increase wear properties
Hardness - Defined in terms of the method of measurement. Usually the resistance to indentation. Stiffness or temper of wrought products.
Hardness test - Hardness testing consists of pressing an indenter into a flat surface under a perfectly controlled load, then measuring the dimension of the resulting indentation. The three methods most commonly used for stainless steel are the Rockwell B, Rockwell C and Vickers tests. The higher the number, the harder the material.
HARP - An abbreviation for "hot rolled annealed and pickled."
Heat - Term referring to batch of refined stainless steel; a charged oxygen or electric furnace full of stainless steel. A heat of stainless steel can be used to cast several slabs, billets, or blooms.
Heat-Affected Zone (HAZ) - The part of a metal that is not melted during cutting, brazing, or welding, but whose microstructure and physical properties are altered by these processes.
Heat treatment - Altering the properties of stainless steel by subjecting it to a series of temperature changes. To increase the hardness, strength, or ductility of stainless steel so that it is suitable for additional applications. The steel is heated and then cooled as necessary to provide changes in the structural form that will impart the desired characteristics. The time spent at each temperature and the rates of cooling have significant impact on the effect of the treatment.
Heavy structural shapes - A general term given to rolled flanged sections that have at least one dimension of their cross sections three inches or greater. The category includes beams, channels, tees and zees if the depth dimension is three inches or greater, and angles if the length of the leg is three inches or greater.
High frequency welding - A technique employed in the manufacture of electric resistance weld pipe. Typical radio frequency power for welding is supplied at 450,000 cycles/sec.
High Strength Low Alloy (HSLA) - A specific group of steel in which higher strength, and in some cases additional resistance to atmospheric corrosion or improved formability, are obtained by moderate amounts of one or more alloying elements such as columbium, vanadium, titanium, used alone or in combination.
High strength stainless steels - Materials rapidly gaining favor with designers in the aerospace, military and other industries that are seeking new materials offering high strength, lower weights and lower life cycle costs. An alloy is generally considered a high strength stainless steel when it meets several key requirements. First, it must have an ultimate tensile strength (UTS) of 225 ksi (1550 MPa) or more, and a minimum yield strength (YS) of 200 ksi (1378 MPa). Tensile ductility must be good, with a minimum 10% elongation preferred.
High-strength steels - Newly developed steels that are generally defined as having tensile strengths between 270–700 MPa (39–102 ksi). Ultra-high-strength steels (UHSS) are defined as steels with tensile strengths greater than 700 MPa (102 ksi). Advanced high-strength steels (AHSS) may start at 400 MPa (58 ksi).
High-carbon steel - Steel with more than 0.3% carbon. The more carbon that is dissolved in the iron, the less formable and the tougher the steel becomes. High-carbon steel’s hardness makes it suitable for plow blades, shovels, bedsprings, cutting edges, or other high-wear applications.
Home scrap - Waste steel that is generated from within the steel mill, through edge trimming and rejects. It normally is sent directly back to the furnace.
Hot band (Hot-Rolled Stainless Steel) - Stainless steel that has been rolled on a hot-strip mill. It can be sold directly to customers or further processed into other finished products.
Hot briquetted iron (HBI) - Direct reduced iron that has been processed into briquettes. Instead of using a blast furnace, the oxygen is removed from the ore using natural gas and results in a substance that is 90%–92% iron. Because DRI may spontaneously combust during transportation, HBI is preferred when the metallic material must be stored or moved.
Hot end - The section of a steelmaking complex from the furnace up to, but not including, the hot-strip mill.
Hot forming - Hot forming operations are used widely in the fabrication of stainless steel to take advantage of their lower resistance to shape change. High temperature reduces their yield strengths, and this results in a marked lowering of the force that is required to bring about plastic movement or flow from one shape to another. (hot rolling, hot stretching, etc.)
Hot metal - The name for the molten iron produced in a blast furnace. It proceeds to the basic oxygen furnace in molten form or is cast as pig iron.
Hot mill - The rolling mill that reduces a hot slab into a coil of specified thickness; the processing is done at a relatively high temperature (when the steel is still “red”).
Hot roll - Product that is sold in its “as produced state” off the Hot mill with no further reduction or processing steps aside from being pickled and oiled (if specified).
Hot stamp - Permanent marking placed on pipe as employed by manufacturer or as established by specification.
Hot working - Deformation (forging) above the recrystallization temperature of the steel. Here the metal continuously anneals itself as the work progresses. There is no increase in strength on cooling to ambient temperature and annealing is not needed after hot working.
Hot-dipped - Steel is run through a molten zinc coating bath, followed by an air stream “wipe” that controls the thickness of the zinc finish.
Hot-rolling mill - Equipment on which solidified steel preheated to a high temperature is continuously rolled between two rotating cylinders.
Hot-strip mill - A rolling mill of several stands of rolls that converts slabs into hot-rolled coils. The hot-strip mill squeezes slabs, which can range in thickness from two to ten inches, depending on the type of continuous caster, between horizontal rolls with a progressively smaller space between them (while vertical rolls govern the width) to produce a coil of flat-rolled steel about a quarter-inch in thickness and a quarter mile in length.
Hydrate - An aluminum oxide with three molecules of chemically combined water.
Hydroforming - A forming process in which a tube is placed into a forming die. The tube is then formed to the shape of the die through the application of internal water pressure. The hydroforming process allows for severe shape deformation, making it ideal for automotive structural parts such as engine cradles, radiator supports, and body rails. Various shaped and sized holes can be punched in the tube almost anywhere during the process.
Hydrogen embrittlement - The absorption of hydrogen by a metal resulting in a loss of ductility.
Hydrogen stress cracking - Cracking of a metal resulting from the combination of hydrogen and tensile stress.
Hydrogen-induced cracking - Stepwise internal cracks that connect adjacent hydrogen blisters on different planes in the metal, or to the metal surface.
Hydrostatic test - Normal mill test as required by specifications. The pipe or tube ends are sealed and high pressure water is introduced to predetermined pressures as required by specifications.
HYL I, HYL III - Processes for producing DRI and HBI developed by Hylsa. The processes reduce iron ore lump or pellets with reformed natural gas in a vertical shaft furnace. The HYL I process uses four fixed-bed reactors; HYL III uses a single-shaft furnace.top
I.D. - Inside Diameter. See OD
I-Beams - Structural sections on which the flanges are tapered and are typically not as long as the flanges on wide-flange beams. The flanges are thicker at the cross sections and thinner at the toes of the flanges. They are produced with depths of three inches to 24 inches.
Impact test - A test performed at a specified temperature (usually lower than ambient) to determine the behavior of materials when subjected to high rates of loading, usually in bending, tension or torsion. The quantity measured is the energy absorbed in breaking the specimen by a single blow, as in a Charpy Test.
Ingot - A form of semi-finished type of metal including stainless steel. Liquid metal is teemed (poured) into molds, where it slowly solidifies. Once the metal is solid, the mold is stripped, and the 25- to 30-ton ingots are then ready for subsequent rolling or forging.
Ink mark - Continuous printing identification associated with NPS 1 1/2 and smaller pipe or tube. Detail is normally limited to the trademark and "Made in USA".
Integrated mills - Facilities that combine all the stainless steel making facilities from melt shop through hot rolling and cold finishing, to produce mill products.
Intergranular corrosion - Preferential corrosion cracking at or along the grain boundaries of a metal.
Intergranular stress corrosion cracking - Stress corrosion cracking in which the cracking occurs along grain boundaries.
Interstitial alloy - In an interstitial alloy, the atoms of the materials that make up the alloy are quite dissimilar in size and the smaller atoms are situated neatly into the gaps between the larger atoms. These gaps between the larger atoms are called interstices.
Interstitial free steel - A recently developed sheet steel product with very low carbon levels that is used primarily in automotive deep-drawing applications. Interstitial Free Steel’s improved ductility (drawing ability) is made possible by vacuum degassing.
Iron carbide - One of several substitutes for high-quality, low-residual scrap for use in electric furnace steelmaking. Iron carbide producers use natural gas to reduce iron ore to iron carbide.
Iron ore - Mineral containing enough iron to be a commercially viable source of the element for use in steelmaking. Except for fragments of meteorites found on earth, iron is not a free element; instead, it is trapped in the earth’s crust in its oxidized form.
Iron-based superalloys - These alloys are at the highest end of the range of temperature and strength. Additives such as chrome, nickel, titanium, manganese, molybdenum, vanadium, silicon, and carbon may be used. These superalloys are also referred to as “super chrome stainless steels.”
ISO - International Organization for Standardization.top
Joint - One length of pipetop
Kip - A unit of weight equal to 1,000 pounds used to express dead weight.
L grades - Mostly applied to 304L (1.4307) and 316L (1.4404). Steels with less than 0.030% carbon to prevent sensitization during thermal cycling, notably welding
Ladle - A “bucket” lined with refractory (heat resistant) bricks, used to transport molten steel from process to process in a steel plant.
Ladle Metallurgy Furnace (LMF) - An intermediate steel processing unit that further refines the chemistry and temperature of molten steel while it is still in the ladle. The ladle metallurgy step comes after the steel is melted and refined in the electric arc or basic oxygen furnace, but before the steel is sent to the continuous caster.
Lance - A long metallic tube through which oxygen is blown into the BOS vessel under high pressure.
Legacy costs - Any costs that are associated with prior operations. Employee liabilities (pensions and health care benefits) and environmental cleanup costs usually are included under this moniker.
Leveling - The process by which a leveling machine flattens metal strip, coil, or sheets by bending it up and down over the interrupting arcs of upper and lower sets of long, slender work rolls. Machines generally employ 17, 19, or 21 relatively small diameter rolls whose deflection under load is controlled by additional back-up rollers and a rigid frame.
Leveling line - A machine that smoothes any physical deficiencies in the sheet before it is shipped to the customer.
Light-gauge stainless steel - A very thin sheet of stainless steel that has either been temper rolled or passed through a cold reduction mill.
Light-gauge steel - Very thin steel sheet that has been temper-rolled or passed through a cold-reduction mill. Light gauge steel normally is plated with tin or chrome for use in food containers.
Line pipe - A pipe extending over long distances that transports oil, natural gas, and other fluids.
Line pipe - Pipe used in the surface transmission of oil, natural gas and other fluids.
London Metal Exchange (LME) - A metals trading center for the Western World. The LME also determines the metal price for aluminum trading for current and future delivery.
Long (Net) Ton - 2,240 pounds.
Long products - Category of stainless steel that includes rods, bars, and structural products that are described as long rather than flat.
Low carbon stainless steel - Stainless steel containing less than 0.03% carbon.
Low-carbon steel - Steel with less than 0.005% carbon is more ductile (malleable). Low carbon steel is capable of being drawn out or rolled thin for use in automotive body applications. Carbon is removed from the steel bath through vacuum degassing.
LS - Limited Service pipe not meeting specification, usually rejected at the mill
LT - Loaded Trucks used in price quotation to indicate seller pays for handling
LTC - Long Thread and Coupling (OCTG casing connection)top
M sections (Bantam Beams™, Junior Beams™) - Light footweight beams primarily used in the construction of pre-engineered housing. These beams are produced in lighter footweights, usually six to ten pounds per foot, than traditional structural products.
Machining - Refers to performing multiple processes to a piece of metal to produce a customer specified component part.
Magnesium - A light, silvery, moderately hard metallic element used in processing metals and chemicals, and in alloying aluminum to give it desired metallurgical properties.
Magnetic particle - One of several methods of non destructive testing. A non destructive method of inspection for determining the existence and extent of possible defects in ferromagnetic materials. Finely divided magnetic particles, applied to the magnetized part, are attracted to and outline the pattern of and magnetic leakage fields created by discontinuities.
Magnetic permeability - Test simply determines the level of magnetism.
Magnetic properties - The properties of a material that reveal its elastic and inelastic behavior where force is applied, thereby indicating its suitability for mechanical application; for example, tensile strength, elongation, hardness and fatigue limit.
Man-hours per ton (M-H/T) - This is a measure of labor efficiency - the ratio of total hours worked by steel employees to the tons shipped for a given period of time. Changes in the inventory level and work that is contracted out will affect the reported measurement.
Martensite - A hard supersaturated solid solution of iron characterized by an acicular (needlelike) microstructure.
Martensitic (Martensitic stainless steel) - Small category of stainless steel characterized by the use of heat treatment for hardening and strengthening. Martensitic stainless steels are plain chromium steels with no significant nickel content. They are utilized in equipment for the chemical and oil industries and in surgical instruments. The most popular martensitic stainless steel is type 410 (a grade appropriate for non-severe corrosion environments requiring high strength). Martensitic stainless steels typically containing 12% chromium, a moderate level of carbon, and a very low level of nickel.
Matte finish - A dull or grit surface appearance achieved by rolling on rolls that have been roughened by mechanical, chemical, or electrical means to various degrees of surface texture.
Mechanical properties - A measure of the metal’s response to an applied force or load (i.e. stress).The commonly reported mechanical properties include yield strength, tensile strength, elongation, reduction of area (RA), hardness, toughness (Charpy V) and fatigue.
Mechanical properties (Physical properties) - Properties determined by mechanical testing, such as yield strength, ductility, ultimate tensile strength, hardness, bendability, impact strength, etc.
Megapascal - A measure of pressure defined as MPas.
Merchant bar - A group of commodity steel shapes that consist of rounds, squares, flats, strips, angles, and channels, which fabricators, steel service centers, and manufacturers cut, bend, and shape into products. Merchant products require more specialized processing than reinforcing bar.
Metric ton - 1000 kilograms. 2,204.6 pounds or 1.102 short tons.
Mid weld - Two or more joints welded to form a longer one
Mild steel - The most common form of steel as its price is relatively low while it provides material properties that are acceptable for many applications. Low carbon steel contains approximately 0.05-0.15% carbon and mild steel contains 0.16–0.29% carbon, therefore it is neither brittle nor ductile. Mild steel has a relatively low tensile strength, but it is cheap and malleable; surface hardness can be increased through carburizing.
Mill products - Generally mill forms of sheet, strip, plate, bar rod and semi-finished
Mini mill - A small non-integrated or semi-integrated steel plant, generally based on electric arc furnace steelmaking. Mini mills produce rods, bars, small structural shapes and flat rolled products.
Molybdenum (Mo) - Molybdenum, with an atomic number of 42, is a soft, silvery-white, chemical element that is considered to be a transition metal. It is used in steel as a hardening agent. When molybdenum is used with chromium, it increases an alloy's corrosion resistance.
Monel - Invented by the International Nickel Co., and composed basically
to two-thirds nickel, one-third copper. Monel has good strength, excellent corrosion resistance against salt water and in high temperatures, but is very expensive.
MPa - The force per unit area required to break a material in such a manner is the ultimate tensile strength or tensile strength at break. 1 MPa = 145.0377 psi.
MS - Military Standards. The overriding characteristic of MS fittings compared to commercial products is the extensive inspection and lot traceability for MS, guaranteeing the chemical, physical and dimensional qualities. While commercial fittings may look similar and happen to pass many tests given MS products, the commercial fittings lack the pedigree of guaranteed quality or chemical, physical and dimensional aspects that users who order MS fittings rely on.
MSS - Martensitic Stainless Steeltop
Natural edge - Occurs when there is no final trimming after cold lamination.
Nickel (Ni) - An alloying element used as a raw material for certain classes of stainless steel. Nickel provides high degrees of ductility (ability to change shape without fracture) as well as resistance to corrosion. Approximately 65% of all nickel is used in the making of stainless steel. Nickel has an atomic number of 28.
Nickel-based superalloys - Alloy metal produced for high-performance, high-temperature applications such as nickel-iron-chrome alloys and nickel-chrome-iron alloys.
Niobium - An exotic alloy valued for its strength at extremely high temperatures and its ability to superconduct, or pass electricity with minimal resistance, at very low temperatures. It is used in aerospace applications, in superconducting magnets in MRI (magnetic resonance imaging) equipment, when alloyed with titanium, and in particle accelerators.
Nitronic 50 - (UNS S20910) Invented by the Armco Steel Company, Nitronic 50 is a chromium-nickel-manganese-molybdenum austenitic stainless steel. It remains completely non-magnetic after severe cold working or exposure to low temperatures. Sought after for its higher strength and greater corrosion resistance. NM - Stands for non-magnetic. Varying standards of magnetic units are applied to different metals for this designation.
No. 1 heavy melt - Obsolete steel scrap grade, at least one-quarter inch in thickness and in sections no larger than five feet by two feet. Much of the metal comes from demolished buildings, truck frames and heavy duty springs. Mini-mills are primary consumers of No. 1 heavy scrap.
Nominal - Pipe size or wall thickness as specified (not actual). Sizes refer to approximate ID, even though OD is the fixed dimension.
Non-alloy steel - Steel which does not have any alloy elements.
Non-ferrous metal - Metal or alloy that contains no iron.
Non-grain-oriented - Because there is no preferential direction for magnetization, non-grain-oriented steel is best used in rotating apparatus such as electric motors. See Grain oriented
Normalizing - Heating a ferrous material to a suitable temperature above the transformation range and then cooling in air to a temperature substantially below the transformation range.
NPS - A dimensionless designator for such traditional terms as "nominal diameter", "size", and "nominal size". Corresponds to actual outside diameter only in sizes 14 inches and over.
NUE - Non upset end OCTG tubing description (not as common as EUE)top
O.D. - Outside Diameter.
Obsolete scrap - Iron-bearing items such as old automobiles; household appliances; farm, office, and industrial equipment; ships and railroad cars; buildings and bridges that have completed their useful life which can be recovered from the junkyard and remelted. The residual impurity of such scrap normally relegates obsolete scrap to the mini-mills. see No. 1 Heavy Melt
Oil Country Tubular Goods (OCTG) - Label applied to the pipe products used by petroleum exploration customers. OCTG includes casing, drill pipe, and oil well tubing, which, depending on their use, may be formed through welded or seamless processes.
Oiled - See Black oiled.
Open hearth furnace - A broad, shallow hearth to refine pig iron and scrap into steel. Heat is supplied from a large, luminous flame over the surface, and the refining takes seven to nine hours. Open Hearths, at one time the most abundant steelmaking furnaces among integrated companies, have been replaced by the basic oxygen furnace.
Operating rates - The ratio of raw steel production to the mill’s stated capacity. Each December, steel companies report to the AISI their estimated capacity (if they could sell all steel they produced) for the following year, adjusted for any facility downtime.
Order rate - The ratio of new orders recorded to the mill’s capacity to produce the steel to fill the orders. Many analysts view trends in the order rate as harbingers of future production levels.
Ore - An iron-containing material used primarily in the melting furnace.
Oscillating - A method of winding a narrow strip of stainless steel over a much wider roll. This allows for more stainless steel per roll and allows the customer to have longer processing runs.
Oxidation - Rust or corrosion due to exposure to oxygen.top
Passivating - Technically, passivation is not cleaning but is a process of dipping fittings into an acid solution to rapidly form a chromium oxide on the surface of the material, creating a passive film that protects stainless from further oxidation. In common commercial terms (meaning non-military and aerospace), passivating means cleaning to users, and the terms "passivating" and "cleaning" are used interchangeably. see Passive film
Passivation - The treatment of the surface of stainless steels with dilute solutions (or pastes) of nitric acid HNO3.This, being an oxidizing acid, promotes the formation and improves the integrity of the passive film on any freshly created surface (e.g. through grinding, machining or mechanical damage). The acid treatment also has the secondary beneficial effect of dissolving any free iron or steel contamination that may have been picked up during handling, forming or fabrication operations, and if this were not removed would impair the corrosion resistance. Nitric acid is the only acid that should be used to effect passivation of stainless steels.
Passivation layer - A passivation layer is an invisible, adamantine, non-reactive film that forms on the surface of steel and other materials in a caustic environment. This film, which is only a few atoms in thickness, helps prevent corrosion.
Passive - Surface condition making the steel corrosion resistant, i.e. the passive film is stable under the prevailing conditions. Stainless steels are intended to be used under conditions where they maintain their passive condition.
Passive film - Chromium contents in excess of ±11% Cr in stainless steels result in the formation of a chromium oxide passive film on the surface, provided there is a sufficient availability of oxygen for its formation. This passive film is extremely thin, continuous, tenacious, stable and self-repairable. It renders the surface inert to many chemical reactions and therefore passive. This is stainless steel’s natural built-in corrosion resistance.
PE - Acronym for Plain End
Peak earnings - The ultimate earnings level of a company at the top of the business cycle. This is the expected profit during the time of the highest commodity demand and the strongest product pricing.
PEB - Acronym for Plain End Beveled
Pellets - Fine particles of iron ore mixed with bonding clay and roasted into hard round balls for blast furnace feed.
Permeability - A magnetic property of materials related to their ability to be attracted by a permanent magnet or influenced by a magnetic field. Austenitic stainless steels e.g. 1.4301(Type 304) when annealed have relative permeability levels just above 1 and are said to be non-magnetic. The magnetic permeability can be increased by cold work or cooling to sub-zero temperatures due to the formation of the magnetic martensitic phase
pH - A scale for showing the hydrogen ion concentration of solutions. Acids have pH values between 1 and 6, bases (alkalis) between 8 and 14 and water (neutral) has a value of 7.
Physical properties - Defined as the properties other than mechanical that pertain to the physics of a material, e.g. density, electrical conductivity, heat conductivity and thermal expansion.
Pickle (pickling) - Chemical (usually acid) treatments that remove a thin layer of surface metal. Pickling with nitric acid is also used to remove iron contamination from stainless steel surfaces.
Pickling - The removal of the oxide film from the surface of a metal by chemical means. An exposure to high temperature (e.g. during welding or heat treatment) will scale the surface. In the case of stainless steel such high temperature scale has inferior corrosion resistance and must be removed. Pickling, using formulations of hydrofluoric (HF) and nitric HNO3 acids, removes the scale and restores the corrosion resistance. For applications in aggressive environments it is advisable to develop full corrosion resistance by a passivation treatment subsequent to the pickling operation.
Pickling paste - A commercially available product that performs the pickling function when used on the surface of stainless steel.
Pig iron - The name for the melted iron produced in a blast furnace, containing a large quantity of carbon (above 1.5%). Named long ago when molten iron was poured through a trench in the ground to flow into shallow earthen holes, the arrangement looked like newborn pigs suckling. The central channel became known as the “sow,” and the molds were “pigs.”
Piling (Sheet piling) - A structural steel product with edges designed to interlock; used in the construction of cofferdams or riverbank reinforcement.
Pin - External (male) threaded end.
Pinch pass - A final cold rolling operation in the production of coil (strip) to improve shape and flatness also known as skin pass. This process result in finish 2B.
Pipe - Technically a tube is used to transport fluids or gases. However, pipe and tube are often used interchangeably in steel lexicon, with a given label applied primarily as a matter of historical use.
Pitting - A form of localized corrosion (attack) often associated with the presence of chlorides in the environment.
Pitting corrosion - Pitting indicates deep corrosion in localized spots on a fastener. Dirt or grease on certain portions of a fastener may block oxygen from that surface, thus impeding the passive film that protects stainless from corrosion.
Plate - Stainless steel measuring more than ten inches wide with a thickness ranging from 3/16 of an inch and over.
Postweld heat treatment - Heating and cooling a weldment in such a way as to obtain desired properties.
Powder metals - Fabrication technology in which fine metallic powder is compacted under high pressure and then heated at a temperature slightly below the melting point to solidify the material. Primary users of powder metal parts are auto, electronics and aerospace industries.
Precipitation hardening - A strengthening mechanism produced by heat treatment. Can only be done on specially formulated steels e.g. 1.4542 (17/4PH), 1.4594 (FV 520B). High strengths are achieved with better impact toughness than with ordinary martensitic steels e.g. 1.4021 (Type 420), 1.4057 (Type 431). Corrosion resistance is generally comparable to type 1.4301 (Type 304). Applications for PH stainless steels include shafts for pumps and valves as well as aircraft parts.
Precision plate sawing - Involves sawing plate (primary aluminum plate products) into square or rectangular shapes to tolerances as close as 0.003 of an inch.
Prompt (Industrial) scrap - Excess steel that is trimmed by the auto and appliance stampers and auctioned to scrap buyers as factory bundles. This is a high-quality scrap as the result of its low-residual content and consistent chemistry.
Proof load - A test load that a fitting must undergo without showing significant deformation. It is usually 50% +- of yield strength.
Protective coating - A temporary adhesive protective film attached to the surface that protects the surface during forming and handling operations that is stripped before final use.
Protector - Plastic, steel or composite cap to protect threads from handling damage
PSI - Pounds per square inch. See MPa
PSIG - Pounds per square inch gage.
Pulverized Coal Injection System (PCI) - A blast furnace enhancement to reduce an integrated mill’s reliance on coke (because of environmental problems with its production). Up to 30% of the coke charged into the blast furnace can be replaced by this talcum-like coal powder, which is injected through nozzles at the bottom of the furnace.
Punching - The cutting of holes into carbon steel beams or plates by pressing or welding per customer specifications.top
Q-BOP - Modified Basic Oxygen Furnace in which the oxygen and other gases are blown in from the bottom, rather than from the top. While the Q-BOP stirs the metal bath more vigorously, allowing for faster processing, the design produces essentially the same steel grades as the top-blowing basic oxygen furnace. Today’s state-of-the-art furnace design combines the previous technologies: 60% of the oxygen is blown from above, with the rest blown through the bottom of the vessel.
Qualification trials - The testing required for a new process adopted to make certain grades of steel with exacting end uses. In order for the process to become qualified, the steel made by the process must be tested.
Quench hardening - A process of hardening a ferrous alloy of suitable composition by heating within or above the transformation range and cooling at a rate sufficient to increase the hardness substantially. The process usually involves the formation of martensite.
Quenching - A type of heat treatment that can be used to harden stainless steel. First the stainless steel is heated until it is in an austenitic state and then promptly cooled via air, oil, water, brine, etc. Typically, depending on the intended use, the steel needs to be tempered after being quenched.top
R & D - Reamed and Drifted. Pipe commonly used in water wells that has a special, heavy duty coupling and a guaranteed I.D. clearance.
Range - (R1, R2, R3) lengths of OCTG (Range 1 casing 16-25') (Range 2 casing 25-34') (Range 3 casing 34-48') (Range 1 tubing 20-24') (Range 2 tubing 28-32')
Reducing agent - Either natural gas or coal can be used to remove the oxygen from iron ore in order to produce a scrap substitute. In gas-based processes, the iron ore is heated in a vessel as reformed natural gas passes through. In coal-based processes, iron ore is combined with gasified or ground coal and heated. The oxygen in the ore combines with carbon and hydrogen in the gas or coal, producing reduced, or metallic, iron.
Refining - A stage in the process of making crude steel, during which the crude steel is further refined (i.e. most residual impurities are removed) and additions of other metals may be made before it is cast.
Refractory brick - Heat-resistant brick. Because the brick’s melting point is well above the operating temperatures of the process, refractory bricks line most steelmaking vessels that come in contact with molten metal, like the walls of the blast furnace, sides of the ladles, and inside of the BOF.
Reinforcing bar (Rebar) - A commodity-grade stainless steel used to reinforce concrete in highway and building structures.
Reline - The process of replacing the refractory lining of a liquid steel vessel. Once it wears out, the brick lining of a furnace must be cooled, stripped, and replaced. This maintenance can be significant because a blast furnace reline may require up to three months to complete.
Residuals - The impurities remaining in mini-mill stainless steels resulting from the wide variety of metals entering the process.
Reversing mill - A stand of rolls that passes stainless steel back and forth between the rolls in order to reduce the stainless steel sheet or plate. The distance between the rolls is reduced after each pass.
Rockwell hardness - Relative resistance of a metal to indentation by a diamond cone, as expressed in hardness scale units (A, B, C or G) See Brinell, Vickers hardness test
Rod - Round, thin semi-finished steel length that is rolled from a billet and coiled for further processing. Rod is commonly drawn into wire products or used to make bolts and nails. Rod trains (rolling facilities) can run as fast as 20,000 feet per minute - more than 200 miles an hour.
Roll force systems - Mill stands place considerable pressure on slabs, blooms and coils to further process the material. There are two general ways of applying the force to the steel - screw and hydraulic systems.
Rolling mill - Equipment that reduces and transforms the shape of semi-finished or intermediate steel products by passing the material through a gap between rolls that is smaller than the feedstock.
Roughing stand - The first rolling stand through which metal passes during hot rolling. Once reduced by the roughing stands, the metal continues on to the finishing stands where smoother rolls with a smaller gap are used to complete the hot roll process.
Routing - Produces various sizes and shapes of aluminum plate according to customer-supplied drawings through the use of CNC controlled machinery.top
SAW - Submerged arc weld a method of producing very large OD pipe or tube.
Sawing - Cutting metal into customer specified lengths, shapes, or sizes.
SC - Square cut plain end pipe.
Scale (Scale removal) - The oxide that forms on the surface of stainless steel, after exposure to high temperature.
Scaling temperature - Temperature above which an arbitrary rate of surface oxidation in air occurs. Often expressed in a weight gain per unit surface area per specified time unit e.g. gm/cm2/hour
Schedule - Numbers assigned to different wall thicknesses of pipe or tubing (i.e. sch. 40).
Scrap - Iron-containing stainless steel material that is normally remelted and recasted into new stainless steel. Home scrap is left over stainless steel generated from edge trimming and rejects within the mill. Also, industrial scrap that is trimmed by stampers and auctioned to buyers.
Scrap (Ferrous) - Ferrous (iron-containing) material that generally is remelted and recast into new steel. Integrated steel mills use scrap for up to 25% of their basic oxygen furnace charge; 100% of the mini-mills’ raw material for their electric furnaces generally is scrap.
Scrap substitute - Raw material that can be charged in place of scrap in electric arc furnaces and basic oxygen furnaces. Scrap substitutes include, among others, DRI, HBI, iron carbide, and pig iron.
Screw (Incline Plane) - This older method used the basic principle of the screw to adjust the space between the mill rolls. Because metal touches metal, these configurations will wear down over time and can cause quality problems.
Scrubber - An air pollutant device that reduces the temperature of an emission – a liquid spray is used to remove pollutants from a gas stream by absorption or chemical reaction.
SEA - Special End Area inspection to check for defects at either end of a steel tube that is also being inspected electronically. (EMI misses the ends.)
Seamless pipe /Seamless tube - Pipe or tube produced from a solid billet that is heated and rotated under pressure. This rotating pressure creates a hole in the middle of the billet, which is then formed into a pipe or tube by a mandrel.
Secondary stainless steel - Stainless steel that has been rejected by an original customer because of a defect in the chemistry, gauge, or surface quality. Mills then search for another customer that will accept the stainless steel at a discount.
Secondary steel - Steel that does not meet the original customer’s specifications because of a defect in its chemistry, gauge or surface quality. Mills must search to find another customer (that can accept the lower quality) to take the off-spec steel at a discount. While secondary will not affect the reported yield, margins will suffer.
Semi-finished products - Steel products such as billets, blooms and slabs. These products can be made by direct continuous casting of hot steel or by pouring the liquid steel into ingots, which are then hot-rolled into semi-finished products.
Semi-finished stainless steel - Stainless steel products such as blooms, billets, or slabs that are then rolled and processed into beams, bars, sheets, etc.
Semi-finished steel - Steel shapes, for example, blooms, billets, or slabs, that later are rolled into finished products such as beams, bars, or sheet.
Sendzimir mill (Z-Mill) – A compact mill used for rolling cold coils of stainless steel in order to make the steel thinner, smoother, and stronger.
Sensitization - The phenomenon in austenitic stainless steels that causes a change to occur in the grain boundaries when heated in the general range of 850° to 1475° F. This change destroys the passivity in these locations.
Service center / Steel service center - An operation that buys metal, stores it (often processing it in some way), and then sells it in a slightly different form than it was purchased from the producing mills. Service centers are manufacturers to the extent that they add labor to steel by providing a service.
Shape correcting - Levelers, edge trimmers, and temper mills reshape processed stainless steel to meet customers’ specifications. Reshaping is needed from processes that cause deformities in the stainless steel.
Shearing - Trimming of the edges of sheet strip to make them parallel. This done at either the stainless steel mill or at the stainless steel processor.
Sheet - A stainless steel flat rolled product that is under 3/16 inches in thickness and 24 inches and over in width.
Sheet piling - Rolled sections with interlocking joints (continuous throughout the entire length of the piece) on each edge to permit being driven edge-to-edge to form continuous walls for retaining earth or water.
Sheet steel - Thin, flat-rolled steel. Coiled sheet steel accounts for nearly one-half of all steel shipped domestically and is created in a hot-strip mill by rolling a cast slab flat while maintaining the side dimensions. The malleable steel lengthens to several hundred feet as it is squeezed by the rolling mill. The most common differences among steel bars, strip, plate, and sheet are merely their physical dimensions of width and gauge (thickness).
Shoe - Sub sometimes run on bottom of casing string with special metallurgy or design to help pipe to bottom through tight or bridged spots in drill hole
Short (Net) Ton - 2,000 pounds. Normal unit of statistical raw material input and steel output in the United States.
Shot blasting - Blast cleaning using stainless steel shot as the abrasive. Not recommended for stainless steel. Glass beads should be used.
Shredded scrap - Fist-sized, homogenous pieces of old automobile hulks. After cars are sent through a shredder, the recyclable steel is separated by magnets. Mini-mills consume shredded scrap in their electric arc furnace operations.
Sigma phase - An extremely brittle Fe-Cr phase that can form at elevated temperatures in austenitic and ferritic stainless steels.
Silicon electrical steel - A type of specialty steel created by introducing silicon during the steelmaking process. Electrical steel exhibits certain magnetic properties, which make it optimum for use in transformers, power generators, and electric motors.
Sintering - A process that combines ores too fine for efficient blast furnace use with flux stone. The mixture is heated to form clumps, allowing better draught in the blast furnace.
Skelp - A piece or strip of metal produced to a suitable thickness, width and edge configuration, from which welded pipe or tube is made.
Skin milling - Grinds the top and/or bottom of a large aluminum plate into close tolerance.
Slab - A very common type of semi-finished stainless steel which usually measures 6-10 inches thick by 30-85 inches wide and averages 20 feet long. After casting, slabs are sent to a strip mill where they are rolled and coiled into sheet and plate products.
Slag - The impurities in a molten pool of iron. Flux may be added to congregate the impurities into a slag. Slag is lighter than iron and will float allowing it to be skimmed.
Slitting - Cutting a sheet of stainless steel into a smaller strip to meet customers demands.
SMLS - Seamless.
Solution annealed (same as Carbide solution annealed) - A process of heating and removing carbide precipitants (carbon that has broken loose from its stainless steel solution) by heating a finished fitting to over 1,850 degrees F. and cooling it quickly, usually in water, so carbon content goes back into the stainless solution.
Solution heat treatment - Heating a metal to a high temperature and maintaining it long enough for one or more constituents to enter the solid solution. The solution is then cooled rapidly to retain the constituents within.
Solution treatment - A heat treatment that effects the solution of intermetallic compounds or precipitates (e.g. carbides) at high temperatures. Subsequent cooling must be fast enough to prevent their reformation during the cooling cycle.
Solvent cleaning - The removal of contaminants such as oil, grease, dirt, salts, etc. by cleaning with a solvent, steam, vapor, alkali, or emulsion.
Spangle - Finish achieved when zinc is allowed to “freeze” naturally on the sheet – galvanize. Achieved by adding antimony to the hot dip bath.
Spec - Specification
Special Bar Quality (SBQ) - SBQ represents a wide variety of higher quality carbon and alloy bars that are used in the forging, machining, and cold-drawing industries for the production of automotive parts, hand tools, electric motor shafts, and valves. SBQ generally contains more alloys than merchant quality and commodity grades of steel bars, and is produced with more precise dimensions and chemistry.
Specialty alloys - Metals with distinct chemical and physical properties. These alloys are produced for very specific applications and considered to be on the low end of superalloys.
Specialty steel - Category of steel that includes electrical, alloy, stainless, and tool steels. see Alloy steel, Silicon electrical steel, Stainless steels, Tool steels
Specialty tube - Refers to a wide variety of high-quality custom-made tubular products requiring critical tolerances, precise dimensional control and special metallurgical properties. Specialty tubing is used in the manufacture of automotive, construction, and agricultural equipment, and in industrial applications such as hydraulic cylinders, machine parts, and printing rollers. Because of the range of industrial applications, the market typically follows general economic conditions.
Spot market - Sales for delivery in less than three months.
SRL - Single Random Length (16-22 ft. for standard weight ASTM pipe or as defined in specifications).
Stabilization - Making the steel more resistant to intercrystalline corrosion sensitization by adding small amounts of either titanium or niobium to the steel. Grades 1.4541 (Type 321), 1.4550 (Type 347) and 1.4571 (Type 316Ti) are examples of stabilized grades.
Stabilized - This refers to the alloying of titanium (Ti) or niobium (Nb) to the austenitic grades. These elements form stable carbides, thereby locking up the carbon and preventing the formation of chromium carbides. Prevents sensitization and intergranular corrosion (weld decay) in the region next to the weld in welded components of thicker material (> ±2.5mm).
Stainless steel - A family of steels that show a high level of resistance to corrosion that contain more than 10% chromium, with or without other alloying elements. Stainless steel resists corrosion, maintains its strength at high temperatures, and is easily maintained. For these reasons, it is used widely in items such as automotive and food processing products, as well as medical and health equipment. See Type 304, Type 316, Type 409, Type 410, Type 430
Stainless steel sheet or strip - Stainless steel material passes between a matching pair of small work rolls with extremely smooth surfaces, heavily reinforced by clusters of back-up rolls. The rolls reduce the steel to the desired thickness.
Stainless steels - Stainless steels are distinguished from carbon steel by their chromium content (ferritic steels) and, in certain cases their nickel content (austenitic steels). Adding chromium to carbon steel makes it more rust and stain-resistant, and when nickel is added to chromium stainless steel it enhances its mechanical properties.
Standard steels - More common grades of steel that includes Commercial steel (CS), Drawing steel (DS), Deep drawing steel (DDS), Interstitial-free (IF), and Mild.
Statistical Process Control (SPC) - A technique used to predict when a steelmaking function’s quality may deteriorate. By tightly monitoring the product’s variance from specifications, the operator can determine when to apply preventative maintenance to a machine before any low-quality (secondary) steel is produced.
STD - Standard reference to wall thickness of line pipe or tube (=sch. 40 for 1/8 - 10").
Steckel mill - A reversing stainless steel sheet reduction mill with heated coil boxes at each end. Stainless steel sheet or plate is sent through the rolls of the reversing mill and coiled at the end of the mill, reheated in the coil box, and sent back through the Steckel stands and recoiled. By reheating the stainless steel prior to each pass, the rolls can squeeze the stainless steel thinner per pass and impart a better surface finish.
Steel intensity - The amount of steel used per unit of gross domestic product. Intensity reflects the secular demand for steel, as opposed to cyclical demand. The amount of steel used in vehicles and the popularity of alternative materials affect the intensity, or how much steel is needed per unit produced. The state of the economy, however, determines the number of units.
Steel service center inventories - End-of-period material stocks reported by the Metals Service Center Institute (MSCI).
Steel strapping - Banding and packaging material that is used to close and reinforce shipping units, such as bales, boxes, cartons, coils, crates, and skids.
Steel-intensive products - Consumer products such as automobiles and appliances that, because so much of their weight is from steel, exhibit a high demand correlation with steel.
Stencil - Paint spray identification placed on pipe. Specification size, wall, grade, test pressure, method of manufacture and normal mill characters and mill identification are usually included; however, detail varies by specification. "Country of Origin" is included.
Strain - The amount of elongation, force, or compression that occurs in a metal at a given level of stress. Generally in terms of inches elongation per inch of material.
Strength - The ability of stainless steel to oppose applied forces when considering resistance to stretching, forming, compressing, etc.
Stress Corrosion Cracking (SCC) - Slow growth of cracks in stainless steel caused by the combined effect of mechanical stress and exposure to a corrosive environment.
Stress relieving - Heat treatment done to reduce internal (residual) stresses, following cold working. Done to improve resistance to stress corrosion cracking.
Stretch forming - A cold forming method where a sheet is drawn into a die by a press tool and where the edges of the sheet are restrained to make deep cup or bowl shapes. The side wall of the pressing is thinned during forming but the cold working induced prevents fractures in these areas of deep drawing. Sinks produced from one sheet of steel are typically stretch formed using a specially formulated 1.4301 (Type 304).
Stretch reduction - A technique employed in the manufacture of continuous weld pipe and in certain instances in the manufacture of seamless and electric resistance weld pipe. It involves one or several "master" sizes that are stretch reduced or rolled under tension through a number of stands to achieve a variety of standard pipe diameters and walls.
Strip - A stainless steel flat rolled product that is less than 3/16 inches and is less than 24 inches in width. A sheet of metal in which the length is many times the width.
Structurals - An architectural stainless steel product group that includes I-beams, H-beams, wide-flange beams and sheet piling. These products are used in multi-story buildings, bridges, vertical highway supports, etc.
Sub - A short coupling with different types and/or sizes of ends
Substitutional alloy - This is an alloy where the atoms of the materials that make up the alloy have equal or very similar dimensions.
Substrate - Raw material used as an input for steel processing: For example, hot-rolled steel is the substrate for cold-rolling operations.
Super stainless steel - Stainless steel alloys with significant additions of chromium, nickel, molybdenum, or copper. Super stainless steel is used in chemical processing, petroleum refining, marine, heat treating, pollution, and waste control industries where there are requirements for extra corrosion protection, strength, or heat resistance.
Superalloys - Lightweight metal alloys designed specifically to withstand extreme conditions. Conventional alloys are iron-based, cobalt-based, nickel-based, and titanium-based.
T&C - Threaded and Coupled.
T&D - Tested and Drifted one method of verifying integrity of used tubing and casing (OCTG). "Test" refers to hydrostatic: ends are sealed and water pumped inside to a predetermined pressure.
Taconite - A natural mineral containing less than 30% iron that is the primary ore used in blast furnaces.
Tailored blanks - A section of sheet stainless steel that is cut to the manufacturer’s desire. Excess stainless steel is trimmed away to save transportation costs and is ready for the stamper to shape with a die press.
Tandem mill - A cold rolling mill that gives greater strength, a more uniform and smoother surface, and a reduced thickness to the stainless steel sheet. This mill rolls stainless steel through a series of rolls, to achieve a desired thickness and surface quality.
Tantalum (Ta) - An exotic alloy having high corrosion resistance; used for medical implants, chemical process equipment, and aerospace engine components. A by-product of tin processing, this refractory metal is used as a barrier to corrosion of chemical processing and carbide cutting tools, and still-growing use as electronic capacitors and filaments. Melts at 2415° Fahrenheit.
Tap-to-tap time - The length of time between successive melting cycles or heats.
TBE - Threaded Both Ends.
Tee splitting - Involves splitting metal beams. Tee straightening is the process of straightening split beams.
Teeming - Pouring. Ingot molds are filled (teemed) by iron-bearing ladles.
Temper mill - A type of cold-rolling mill, usually with only one or two stands, that finishes cold-rolled, annealed sheet steel by improving the finish or texture to develop the required final mechanical properties. By changing the rolls of the temper mill, steel can be shipped with a shiny, dull, or grooved surface.
Tempered (Temper) - A term applied to cold worked material such as strip, sheet, wire, expressing the range of mechanical properties as produced by the cold work (as is quarter hard, half hard, etc.).
Tempering - Quenched materials are hard and strong, but extremely brittle and of low ductility. Tempering should immediately follow quenching, and be effected at a temperature necessary to increase the toughness and ductility. This will usually incur a loss of hardness and strength, more so if higher tempering temperatures are used. The tempering is chosen to bring about the correct desired combination of properties. The maximum tempering temperature is below that at which change of crystal structure will be induced.
Tempers - Used to define the levels to which austenitic stainless steels are strengthened by cold rolling or cold drawing, without any subsequent annealing operation. Cold rolled sheet, coil and strip are produced to 1/4, 1/2, 3/4 and full hard tempers; wire is produced to annealed, soft, intermediate and spring tempers.
Tensile elongation - The ultimate elongation of an engineering material is the percentage increase in length that occurs before it breaks under tension. The combination of high ultimate tensile strength and high elongation leads to materials of high toughness.
Tensile strength - In tensile testing, the ratio of maximum load to original cross sectional area. Also, called ultimate strength. Usually expressed in pounds per square inch. Tensile strength (or ultimate tensile strength) is defined as the measurement of the amount of force necessary to tear a piece of steel apart. σUTS, or SU is the stress at which a material breaks or permanently deforms. Tensile strength is an intensive property and, consequently, does not depend on the size of the test specimen. However, it is dependent on the preparation of the specimen and the temperature of the test environment and material.
Ternary alloy - An alloy created by combining three constituents. The three materials can all be metals or a combination of metal and non-metal.
Terne - Sheet steel coated with a mixture of lead and tin. Terne principally is used in the manufacture of gasoline tanks, although it also can be found in chemical containers, oil filters, and television chassis.
Thin plate - Steel plate with a thickness that is less or equal to 5.00mm and no larger than 0.30mm. The final thickness of thin plate that is achieved by cold lamination is called cold rolled thin plate.
Threads - Class 1 threads are a loose tolerance. Class 2 threads comprise 90% of stainless fittings and are normal commercial tolerance. Class 3 threads have a stricter tolerance and tighter fit such as socket cap and set screws. No definite relationship exists between tensile strength and tightness or looseness of fit. The symbol "A" added to threads, such as 2A, means external threads (screws), and "B" means internal (nuts).
Tin mill - Continuous tin-plating facility to produce tin mill steel sheet to be used in food and beverage cans and other containers.
Tin plate - Thin sheet steel with a very thin coating of metallic tin. Tin plate is used primarily in can making.
Tin/Chrome plating - A plating process whereby the molecules from the positively charged tin or chromium anode attach to the negatively charged sheet steel. The thickness of the coating is readily controlled through regulation of the voltage and speed of the sheet through the plating area.
Tin-free steel - Chromium-coated steel. Because it is used in food cans just like tin plate, it ironically is classified as a tin mill product. Tin-free steel is easier to recycle because tin will contaminate scrap steel in even small concentrations.
Titanium (Ti) - Titanium and its alloys have very high strength-to-weight ratios. At normal temperatures, they have high resistance to corrosion. Used primarily in aerospace and chemical processing applications. A very ductile and malleable white metal that is used in aviation, aerospace, etc. because of its high strength and light weight.
Titanium-based superalloys - Lightweight, corrosive-resistant alloys suitable for high temperatures. These alloys are very practical for airplane parts. Titanium alloys can be blended with aluminum, iron, vanadium, silicon, cobalt, tantalum, zirconium, and manganese.
Tolerance - Specified allowance (plus or minus) of the given dimension of a finished product due to inaccuracies in manufacturing; usually quite small (thousandths of an inch or very small percentage) and often part of a standard such as ASTM or API.
Toll processing - The act of processing steel for a fee (“toll”). Owners of the steel sheet may not possess the facilities to perform needed operations on the material (or may not have the open capacity). Therefore, another steel mill or service center will slit, roll, coat, anneal, or plate the metal for a fee.
Ton - A unit of measure for stainless steel scrap and iron ore. A Gross Ton = 2,240 pounds. A Long (net) Ton = 2,240 pounds. A Short (net) Ton = 2,000 pounds. A normal unit of statistical raw material input and stainless steel output in the United States. A Metric ton = 1,000 kilograms. (2,204.6 pounds or 1.102 short tons).
Tool joint - Threaded tube, usually thicker and harder, welded onto pipe to provide joint strength and durability exceeding that of flush joint or T&C connections
Tool stainless steels - Hardened stainless steels that are used in the manufacturing of tools and dies.
Tool steels - Steels that are hardened for the use in the manufacture of tools and dies.
Toughness - The ability of a material to withstand sudden impacts. Although all stainless steels have an acceptable level of toughness at normal temperatures, most stainless steels, in common with carbon and alloy steels, show a transition to brittle behavior at low temperature. In contrast, austenitic stainless steels do not show this behavior and consequently are used for cryogenic applications.
Transformation induced plasticity (TRIP) - The microstructure of TRIP steels is retained austenite embedded in a primary matrix of ferrite. In addition to a minimum of 5 volume percent of retained austenite, hard phases such as martensite and bainite are present in varying amounts. TRIP steels typically require the use of an isothermal hold at an intermediate temperature, which produces some bainite. The higher silicon and carbon content of TRIP steels also result in significant volume fractions of retained austenite in the final microstructure.
True capacity - Volume at full utilization, allowing for the maintenance of equipment and reflecting current material constraints. (Bottlenecks of supply and distribution can change over time - capacity will expand or reduce.)
Tube round - See the term Billet.
Tubing - When referring to OCTG, tubing is a separate pipe used within the casing to conduct the oil or gas to the surface. Depending on conditions and well life, tubing may have to be replaced during the operational life of a well.
Tundish - The shallow refractory-lined basin on top of the continuous caster. It receives the liquid steel from the ladle, prior to the cast, allowing the operator to precisely regulate the flow of metal into the mold.
Tungsten (W) - Gray metal with high tensile strength. It is ductile, malleable, and resistant to atmospheric elements and all acids except strong alkalis.
Tungsten materials - Include tungsten and tungsten carbide powders, sintered tungsten carbide products and cutting tools for the metalworking, mining, oil and gas, and other industries requiring tools with extra hardness.
Tunnel furnace - Type of furnace whereby stock to be heated is placed upon cars, which are then pushed or pulled slowly through the furnace.
Twin milling - Grinds one or all six sides of a small square or rectangular piece of aluminum plate into close tolerance.
Type 304 stainless steel - The most common grade; the classic 18/8 stainless steel. An austenitic chromium-nickel alloy used primarily in residential steels, for cookware, utensils, sinks, etc. Type 304 is available in virtually all product forms and finishes.
Type 316 stainless steel - Austenitic (chromium-nickel stainless class) stainless steel containing 2%-3% molybdenum (whereas 304 has none). The inclusion of molybdenum gives 316 greater resistance to various forms of deterioration.
Type 409 stainless steel - Ferritic (plain chromium stainless category) stainless steel suitable for high temperatures. This grade has the lowest chromium content of all stainless steels and thus is the least expensive.
Type 410 stainless steel - The most widely used martensitic (plain chromium stainless class with exceptional strength) stainless steel, featuring the high level of strength conferred by the martensitics. It is a low-cost, heat-treatable grade suitable for non-severe corrosion applications.
Type 430 stainless steel - The most widely used ferritic (plain chromium stainless category) stainless steel, offering general-purpose corrosion resistance, often in decorative applications.top
Ultimate tensile strength - The ultimate tensile strength (UTS) is the maximum resistance to fracture. It is equivalent to the maximum load that can be carried by one square inch of cross-sectional area when the load is applied as simple tension. It is expressed in pounds per square inch. See Tensile strength
Ultra High Strength Steels (UHSS) - A group of newly developed stainless steels with improved properties. Members of this group in include Dual Phase (DP) stainless, Transformation induced plasticity (TRIP) stainless, UHSS alloyed with boron (BOR) stainless, and Martensitic (MART). UHSS steels have a tensile strength of > 700MPa. See High strength stainless steels, Advanced High Strength Steels (AHSS)
Ultrasonic - An electronic method of non destructive testing utilizing sound waves.
Unfair trade suit - A type of lawsuit filed by U.S. companies against their foreign counterparts in response to imports at prices being lower than those in the prices in the U.S. market. Sanctions can be imposed by the ITC and the Commerce Department on foreign producers involved in dumping and government subsidization, if domestic manufacturers can prove material injury.top
Vacuum degassing - An advanced steel refining facility that removes oxygen, hydrogen and nitrogen under low pressures (in a vacuum) to produce ultra-low-carbon steel for demanding electrical and automotive applications. Normally performed in the ladle, the removal of dissolved gases results in cleaner, higher quality, more pure steel (see Ladle Metallurgy).
Vacuum Oxygen Decarburization (VOD) - A refinement of stainless steel that reduces carbon content. Molten, unrefined stainless steel is heated and stirred by an electrical current while oxygen enters from the top. Many undesirable gases escape from the stainless steel and are evacuated by a vacuum pump. Alloys and other additives are then mixed in to refine the molten stainless steel further.
Vanadium (V) - A gray metal that is normally used as an alloying agent for iron and stainless steel. It is also used as a strengthener of titanium-based alloys. Its atomic number is 23. See Columbium, Niobium, Titanium
Vickers hardness test - A testing method developed in 1924 by Smith and Sandland at Vickers Ltd. as an alternative to the Brinell method to measure the hardness of materials. The Vickers test is often easier to use than other hardness tests since the required calculations are independent of the size of the indenter, and the indenter can be used for all materials irrespective of hardness. The basic principle, as with all common measures of hardness, is to observe the questioned material's ability to resist plastic deformation from a standard source. The Vickers test can be used for all metals and has one of the widest scales among hardness tests. The unit of hardness given by the test is known as the Vickers Pyramid Number (HV). See Brinell, Rockwelltop
Walking beam furnace - A hot strip mill reheat furnace where the slab is repeatedly lifted and set down at a more forward point in the furnace; this is in contrast to a batch reheat furnace or a pusher-type reheat furnace.
Weldability - This is not an exactly quantifiable or precise property, but rather implies the ability of the material to be joined by standard welding processes so that the resultant mechanical, physical and chemical properties of the weld zone (i.e. both the weld metal and the HAZ) are at least equivalent to those of the parent metal.
Welding - Welding is a process to attach two or more metals or other materials together. A welder uses heat to melt the areas that are to be joined and then uses a molten filler material to help bond the workpieces together.
Wheelabrating, Shotblasting, and Bead Blasting - Processes that involve pressure blasting metal grid into carbon steel products to remove rust and scale from the surface.
Width - The lateral dimensions of rolled stainless steel, as opposed to the length or the gauge. If width of the stainless steel strip is not controlled during rolling, the edges must be trimmed.
Width - The lateral dimensions of rolled stainless steel, as opposed to the length or the gauge. If width of the stainless steel strip is not controlled during rolling, the edges must be trimmed.
Wire - A cold finished stainless steel product (normally in coils) that is round, square, octagon, hexagon and flats less than 3/16 inches.
Wire rods - Coiled bars of up to 18.5 millimeters in diameter, used mainly in the production of wire.
Wire: Drawn And/Or Rolled - The broad range of products produced by cold reducing hot-rolled steel through a die or series of dies, or through rolls to improve surface finish, dimensional accuracy and physical properties.
WLL - Work Load Limit, this is the recommended weight limit for safe use of a product.
Work hardened steel - Steel which has undergone an enlarged amount of mechanical resistance.
Work hardening - Most metals and alloys will exhibit a slight degree of increase in both strength and hardness if subjected to cold work (e.g. cold rolling, cold drawing, cold bending etc). The austenitic stainless steels show a marked response to work hardening and are therefore termed ‘hardenable by cold work’ or ‘work hardenable’ materials.top
XHY - Extra Heavy pipe about 50% thicker than standard (=sch. 80 for 1/8 - 8")
XXHY - Double Extra Heavy twice as thick as XHY for ½ - 6"
Yield - The ratio of the amount of product compared with the amount of material input to a process or group of processes.top
Yield - The ratio of the amount of product compared with the amount of material input to a process or group of processes.
Yield point - Defined in engineering and materials science as the stress at which a material begins to deform plastically. Prior to the yield point the material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed some fraction of the deformation will be permanent and non-reversible.
Yield strength - The amount of stress a material can withstand without permanent deformation. In some steels there is a marked increase of strain for no increase in stress i.e. yield point. If this does not occur (as in austenitic grades of stainless steel) a stress value for a specified amount of strain (usually 0.2%) is taken. The stress at the yield point or at 0.2% strain is reported as the yield strength.top
Zig-zag coil - A reel that is rolled with an oscillating system and has a width that is greater than the width of the plate or strip.
Zirconium (Zr) - A strong, ductile metal obtained by the chemical processing of zircon-bearing sands. It has good corrosion resistance at high temperatures and is used as a structural material in nuclear reactors and cladding material for uranium.top