Database of properties for steel and alloy materials worldwide.

 

IRON & STEEL GLOSSARY: A-B

A
Abrasive
A substance capable of removing material from another substance in machining, abrasion or polishing.

Abrasive Wear
The removal or displacement of materials from a surface when hard particles slide or roll across the surface under pressure. The particles may be loose or may be part of another surface in contact with the surface being worn.

Abrasion
The process of grinding or wearing away through the use of abrasives, a roughening or scratching of a surface due to abrasive wear.

Abrasion Rate
The rate which material is removed from the surface during abrasion. It is usually expressed in terms of thickness removed per unit of time or distance traversed.

Accelerated Cooling
Employed to improve resistance to impact (toughness) and refine the grain size of certain grades and thickness of plates. Such cooling is accomplished by fans to provide circulation of air during cooling, or by a water spray or dip.

Acid Bottom
Furnace bottom (hearth) of a melting furnace made of acid refractory such as silica bricks.

Acid Brittleness
Brittleness induced in sheet and strip pickled in acid solution to remove scale or during electroplating. This is commonly attributed to absorption of hydrogen.

Acid Fluxes
Used to remove unwanted basic impurities to form a fusible slag. Silica (SiO2), available as sand, gravel, and quartz in large quantities and in a sufficiently pure state, is the only substance that is used as a strictly acid flux.

Acid Process
A steel making process in which steel is refined under an acid slag in an acid refractory lined furnace or converter.

Acid Refractory
A refractory material, acidic in chemical composition and containing high proportion of silica, that is, silica sand and ganister.

Acid Steel
Steel made by acid process.

Adhesive Wear
The removal or displacement of materials from a surface by the welding together and subsequent shearing of minute areas of two surfaces that slide across the surface under pressure. In advance stages, may lead to galling.

Adjustable Mould Width
In order to minimize both the time required to change a mould as well as the mould inventory during slab casting, adjustable mould were first developed which could be adjusted without the mould being removed from the casting machine. More recently, as an alternative to slab slitting, the slab width can be changed during the actual operation. In one design, the mould taper can be adjusted by using different gear ratios for moving the top and bottom of the narrow mould faces.

A. G. C. System
(Automatic Gauge Control) Hydraulic or electric system th at supplies the force to the A.G.C. roll force cylinders.

Age Hardening
A process of aging at atmospheric temperature that increases hardness and strength and ordinarily decreases ductility gradually. Age hardening usually follows rapid cooling or cold working. Takes effect on all cold rolled sheets in storage except fully aluminum killed.

Aging
A change in the properties of certain metal and alloys (such as steel) that occurs gradually with time at atmospheric temperatures (natural aging) or more rapidly at moderately elevated temperatures (artificial or accelerated aging) after a hot working heat treatment or cold working operation. Artificial aging refers to : quench aging (aging following quenching) and strain aging (aging induced by cold-working). Typical properties impacted are: hardness, yield strength, tensile strength, ductility, impact value, formability, magnetic properties, etc. See also Non-aging and artificial aging.

Agglomerating Processes
Fine particles of limestone (flux) and iron ore are difficult to handle and transport because of dusting and decomposition, so the powdery material usually is processed into larger pieces. The raw material's properties determine the technique that is used by mills.
Sinter Baked particles that stick together in roughly one-inch chunks. Normally used for iron ore dust collected from the blast furnaces.
Pellets Iron ore or limestone particles are rolled into little balls in a balling drum and hardened by heat.
Briquettes Small lumps are formed by pressing material together. Hot Iron Briquetting (HBI) is a concentrated iron ore substitute for scrap for use in electric furnaces.
Nodules Fine iron bearing materials moving through a rotary kiln are formed into nodules or lumps by the rolling of the charge heated to incipient fusion temperatures.

Air Hardening
Hardening by cooling in air or gas at ambient temperature from a temperature above the transformation range.

Air Heater Tubes
Tubes used for heating air by means of hot gases, the air passing either inside or outside the tubes.

AISI (American Iron and Steel Institute)
An association of North American companies that mine iron ore and produce steel products. There are 50 member companies and more than 100 associate members, which include customers that distribute, process, or consume steel. The AISI has reorganized into a North American steel trade association, representing the interests of Canada, Mexico, and the United States.

Alkaline Cleaner
Uses an alkaline solution, usually sodium hydroxide, to clean residual oils and iron fines left on the strip from the cold reduction process.

Alkyd
A type of resin made from a polyhydroxy alcohol combined chemically with the acids of various oils. They are particularly adapted for use where hardness and high gloss are required. Used largely for outside decoration.

Alligatoring
The longitudinal splitting of flat slabs in a plane parallel to the rolled surface. Also known as fishmouthing.

Alloy
A substance having metallic properties consisting of two or more elements in which the major constituent is metal, or of metallic and non-metallic elements which are miscible with each other when molten, and have not separated into distinct layers when solid.

Alloying Element
An element (metal or non-metal) added during the making of steel 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.

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, vanadium, lead, niobium or tungsten are present. An enormous variety of distinct properties can be created for the steel by substituting these elements in the recipe.

Alloy Tool Steels
The principle functions of the alloying elements in tool steels are to increase hardenability ; to form hard, wear-resistant alloy carbides; and to increase resistance to softening on tempering. The alloy tool steels may be roughly classified according to the extent of their utilization of these three functions :

1. Relatively Low-alloy Tools Steels : These are of higher hardenability that the plain carbon tool steels in order that they may be hardened in heavier sections or with less drastic quenches and thereby less distortion.

2. Intermediate Alloy Tool Steels : These steels usually contain elements such as tungsten, molybdenum or vanadium, which form hard, were-resistant carbides.

3. High-speed Tool Steels : These contain large amounts of the carbide-forming elements which serve not only to furnish wear-resisting carbides but also to promote secondary hardening and thereby to increase resistance to softening at elevated temperature.

Alloy Surcharge
The addition to the producer's selling price included in order to offset raw material cost increases caused by higher alloy prices.

Alumina
Aluminium oxide (Al2O3), a common constituent of many refractory materials used in steel making.

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.

Anneal
A process, consisting of heating to and holding at a suitable temperature followed by cooling at a suitable rate, used primarily to soften metallic materials, such as steel. This process also simultaneously produces desired changes in microstructure, as in other properties, such as improvement of mechanical or electrical properties, removing stresses, increase in stability in dimensions, facilitation of cold work, improving machinability, etc. Also see Continuous Anneal and Batch Anneal.

Annealing
What A heat or thermal treatment process by which a previously cold-rolled steel coil is made more suitable for forming and bending. The steel sheet is heated to a designated temperature for a sufficient amount of time and then cooled.
Why The bonds between the grains of the metal are stretched when a coil is cold rolled, leaving the steel brittle and breakable. Annealing re-crystallizes the grain structure of steel by allowing for new bonds to be formed at the high temperature. Annealing may be done to induce softness, improving machinability, improving cold-working properties, obtaining a desired structure, reducing stresses and to facilitate diffusion process.
How There are two ways to anneal cold-rolled steel coils : batch and continuous.
(1) Batch (Box). Three to four coils are stacked on top of each other, and a cover is placed on top. For up to three days, the steel is heated in a non-oxygen atmosphere (so it will not rust) and slowly cooled.
(2) Continuous. Normally part of a coating line, the steel is uncoiled and run through a series of vertical loops within a heater: The temperature and cooling rates are controlled to obtain the desired mechanical properties for the steel.
The various annealing processes are : full annealing, sub-critical (or process) annealing, isothermal annealing and spheroidization annealing.

Anneal to Temper
A final partial anneal that softens a cold worked non-ferrous alloy to a specified level of hardness or tensile strength.

Anodes
Tin bars that are put in the plater cells and are important to the plating process in the Tin Mill.

API
American Petroleum Institute.

Arc Heating
A method of heating steel by electric current in which the current is passed through an ionized gaseous medium and the heat radiated by the arc generated is utilized. This practice can be applied through two methods : (a) arcs pass between electrodes supported in the furnace above the metal. In this method, known as indirect-arc heating, the metal is heated solely by radiation from the arcs. Or, (b) arcs pass from the electrodes to the metal. In this method, known as direct-arc heating, the current flows through the metal charge so that the heat developed by the electrical resistance of the metal, though relatively small in amount, is added to that radiated from the arcs.

Argon-Oxygen Decarburization (AOD)
What A process for further refinement of stainless steel through reduction of carbon content.
Why 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 steel making. Additionally, using AOD for refining stainless steel increases the availability of the EAF for melting purposes.
How Molten, unrefined steel is transferred from the EAF into a separate vessel. A mixture of argon and oxygen is blown from the bottom of the vessel through the melted steel. Cleaning agents are added to the vessel along with these gases to eliminate impurities, while the oxygen combines with carbon in the unrefined steel to reduce the carbon level. The presence of argon enhances the affinity of carbon for oxygen and thus facilitates the removal of carbon.

Argon Rinse
To homogenise the melt temperature and composition and also to assist the flotation of deoxidation products during ladle refining of steel, the argon is blown through the melt at a rate of 0.08-0.13 nm3/min for 3 to 5 minutes.

Argon Trim
To facilitate the dissolution of ladle additions during refining of steel, the argon is blown through the melt at a rate of 0.30-0.45 nm3/min.

Argon Stir
To achieve slag-metal mixing in ladle desulphurization of steel during refining, the argon is blown through the melt at a rate of 0.3-0.5 nm3/min.

Artificial Aging
Aging above room temperature.

ASTM
American Society for Testing and Materials. A non-profit organization that provides a forum for producers, users, ultimate consumers, and those having a general interest (representatives of government and academia) to meet on common ground and write standards for materials, products, systems, and services.

ASTM Standards
A series of documents, approved and published by ASTM, that include specifications or requirements, practices, guides, test methods, etc., covering various materials, products, systems or services. In the steel industry, the steel related ASTM standards are used by both the producers and users to ensure that a steel product or service meets all intended requirements. See American Society for Testing and Materials.

Atmosphere Valve
A valve that is located in the exhaust line of a turbine and is designed to open up and get a positive pressure in the exhaust line.

Atomic Hydrogen Welded Tube
Tube made by forming strip, usually of stainless or heat-resisting steel, into tubular form and welding the joint by the atomic hydrogen process.

Atomizing Steam
Low pressure steam which is introduced to the oil gun to help atomize the oil, to assist the burning process, and to keep the oil gun from plugging.

Attemperator
Header connecting the primary and finishing superheaters into which feed water is sprayed to control the final temperature of the steam leaving the boiler.

Austempering
Cooling (quenching) an austenitised steel at a rate high enough to suppress formation of high temperature transformation products, then holding the steel at a temperature below that for pearlite formation and above that for martensite formation until transformation to an essentially bainitic structure is complete.

Austenite
Generally a solid solution of one or more alloying elements in a face centered cubic polymorph of iron (g iron). Specifically, in carbon steels , the interstitial solid solution of carbon g iron.

Austenitic
The largest category of stainless steel, generally non-magnetic, accounting for about 70% of all production. Refers to a particular grain structure of steel which in normal steel exists at high temperature. In stainless steel, this structure exists at room temperature and imparts certain characteristic properties. 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 Grain Size
The size attained by the grains in steel when heated to the autenitic region. This may be revealed by appropriate etching of cross sections after cooling to room temperature.

Automatic
Describes the status of the operation when the O2 pulpit has control and the boiler logic has control.

Automatic Gauge Control
Using hydraulic roll force systems, steel makers 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. The principal components of a computerised AGC are :
1. Mathematical models that adequately describe the process.
2. Instrumentation to measure the required variables of the system.
3. Control equipment, including a digital computer, to perform the required functions for control of the system.

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.

Auxiliary Hydraulic System
Hydraulic system that supplies the force to run the various hydraulic cylinders associated with the finishing mill which are not taken care of by the A.G.C. or C.V.C. Hydraulic systems.

Auxiliary Oil Pump
A steam or electric pump that maintains oil pressure on the controls and the bearings of a turbo blower when it is not up to maximum speed.

Auxiliary Pump
Pump on the auxiliary system which supplies the pressure for the system.

AW-100
The hydraulic oil used in all the hydraulic systems located in the finishing mill oil cellar and the furnace hydraulic system.


B

Back Drafting
Taking the blast furnace out of blast for short periods, often less than 2 hours, (instead of banking) to perform various maintenance functions such as replacing tuyeres or repairing skip cables. This is done usually by opening the chimney valve and the hot-blast valve to a stove that has already been prepared by heating it to temperature and then shutting off the gas valve. As the furnace gas is drawn back into the stove, air is admitted through the peep sights and stove burner, and the operator makes certain that the gas burns in the stove. During the operation, the bleeders at the top of the furnace also are opened to pull some of the furnace gas out through the top.

Baking
Heating after pickling /or pickling and coating to remove hydrogen.

Balanced Steel (Semi-Killed and Semi-Rimmed Steel)
Steel to which controlled amounts of deoxidizers have been added in the liquid stage during tapping and teeming, the object being to reduce the severity of piping. This steel is intermediate between killed and rimming types.

Band
Refers to metal strap signode band that is one half inch wide. This band is used to thread and pull the strip through the line.

Banding
Inhomogeneous distribution of alloying elements or phases aligned in filaments or plates parallel to the direction of working.

Banking
Shutting down the blast furnace for few days. The blast is taken off, the blowpipes are dropped and the tuyere openings are plugged with clay to prevent air from drafting through. Thus, hearth heat is preserved and the furnace can be returned to operation with a minimum effort.

Bar
Finished product of solid section generally supplied in straight length, which are rolled from billets and may be rectangular, square, flats, channels, round, half round or polygonal. The bars may be supplied in coil form also. The dimensions generally conform to the following :
a. Rounds and Half-Rounds : Minimum diameter 5mm.
b. Squares and Polygonal : Minimum 6mm side.
c. Flat Bar (Flat) : A finished product, generally of cross section, with edges of controlled contour and thickness 3mm and over, width 400mm and below and supplied in straight lengths. The product shall have rolled edges only (square or slightly rounded). This group also includes flat bars with bulb that has swelling on one or two faces of the same edge and a width of less than 400mm.

Bar Hold
The end of a bar or forging so reduced as to accommodate a porter bar or tongs for manipulation during forging.

Bare Spot
A location on the strip where coating did not adhere.

Barrel
The part of a forging of major cross section, the length of which usually exceeds the diameter.

Basal Crack
A crack in the ingot base caused by restriction to free contraction during solidification.

Base Box
Unit of area of 112 sheets of Tin Mil products (tin plate, tin free steel or black plate) 14 by 20 inches, or 31,360 square inches. Tin plate is sold, and carried in finished inventory, on a weight per unit area rather than on a thickness basis.

Base Metal Contamination
Dirt or other impurities in the steel strip.

Base Size
The intermediate size in which wire is annealed before drawing; in case of drawn galvanised or drawn tinned wire, the size in which it is galvanised or tinned.

Base Type
Type of base used for cooling; i.e., water or fan.

Base Weight
Tin Mill term; Thickness divided by .00011. Also weight in pounds of one Base Box of tin plate. In finished inventory, base weight is specified instead of decimal thickness.

Basic Flux
Used to remove unwanted acidic impurities to form a fusible slag. The chief natural basic fluxes are limestone, composed primarily of calcium carbonate (CaCO3), and dolomite, composed primarily of calcium-magnesium carbonate (Ca, Mg)CO3.

Basic Oxygen Furnace (BOF)
What A pear-shaped furnace, lined with refractory bricks, that 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.
Why BOFs, which can refine a heat (batch) of steel in less than 45 minutes, replaced open-hearth furnaces in the 1950s; the latter required five to six hours to process the metal. The BOF's rapid operation, lower cost and ease of control give it a distinct advantage over previous methods.
How Scrap is dumped into the furnace vessel, followed by the hot metal from the blast furnace. A lance is lowered from above, through which blows a high-pressure stream of oxygen to cause chemical reactions that separate impurities as fumes or slag. Once refined, the liquid steel and slag are poured into separate containers.

Basic Oxygen Process (BOP)
A process in which molten steel is produced in a basic lined furnace by blowing oxygen into molten iron, scrap and flux materials. The furnace is known as Basic Oxygen Furnace (BOF).

Basic Process
A steel making process in which steel is refined under a basic slag in a basic refractory lined furnace or convertor.

Basic Refractory
A refractory material basic in chemical composition and containing high amounts of such oxides as lime and magnesia, for example, calcined dolomite or magnetite.

Basic Steel
Steel made by basic process.

Basis Weight
See Base Weight.

Batch Anneal
The process by which a large, stationary stack of steel coils (4 coils high) is subjected to a long heat-treating cycle. This process enables the cold-rolled sheet to fully recrystallize into the softest possible product conforming to customer specifications. Controlling the recrystallization process makes a fine-grained microstructure easy to obtain, and minimizes the tendencies for retention of directional properties of the rolled steel which could produce undesirable shapes in the stamping of a cylindrical part such as a can. Also see Anneal and Continuous Anneal.

Batch Pickling
Pickling of steel sheets and other light-gauge sheared lengths performed with specialized equipment in which a batch of sheets are processed together. Agitation of acid bath is employed as a means to increase the pickling rate.

Bath Sample (Spoon Sample)
A sample taken from molten steel in the furnace, for estimation and analysis of constituents.

Bead Test
Commonly used for testing coating adherence, especially on light-gauge material. A bead is used to deform the steel such that the sample contains a continuous ridge.

Becking
Forging the wall of a steel ring between a top becking tool and a becking bar to increase the internal diameter with or without an increase in the external diameter.

Belly Band
The band (strapping) that goes around the outside diameter of a coil.

Bench Drawn
Bars bright drawn in straight lengths on a draw bench.

Bender
Device used in drop forging hammer dies to bring the several sections of the stock or prepared blank into alignment.

Bend Tests
Various tests used to assess the ductility of steel when subjected to bending. Tests may include determination of the minimum radius or diameter required to make a satisfactory bend and the number of repeated bends that the material can withstand without failure when it is bent through a given angle and over a definite radius.

Bessemer Process
A steel making process in which pig iron is refined in an acid refractory lined convertor by blowing air or a mixture of air, carbon dioxide and oxygen or steam through the molten metal. The basic process is known as Thomas process.

Best Patented Steel Wire
Rope wire drawn to tensile strength of 128 to 147 kgf/mm2.

Best Plough Steel Wire
Patented rope wire drawn to a tensile strength of 155 to 170 kgf/mm2.

Bevelling
Refers to pipe; the end preparation for field welding of the joint.

Bi-Coil
Also BY-COIL. Tin Mill term. Customers buy "by coil" or "bi-coil" rather than cut sheets.

Billet
A semi-finished steel form that is input material for manufacturing long products: bars, channels or other structural shapes. A billet is different from a slab because of its outer dimensions; billets are usually square and not exceeding 125x125 mm in cross section with rounded corners, while slabs are 750-1000 mm wide and 50-250 mm thick. Both shapes are generally forged or continually cast or rolled in billet mill / slabbing mill from ingots, but they may differ greatly in their chemistry.

Binders
Soft wire used for tying bundles or coil of wire.

Binders
Binders are used to impart strength to the refractory during manufacture or in service. These are of 4 types :
d. Temporary Binder : Their function is to improve handling strength during manufacture. Temporary binders include paper byproducts, sugar, or certain clays.
e. Chemical Binder : They impart strength during manufacture, after manufacture, or on installation as a monolithic material. Chemical binders include resins, starches, synthetic clays, waxes etc.
f. Chemical Binders : Chemical binders set hydraulically when mixed with water. The primary binders of this type used in refractories are the calcium-aluminate cements which set rapidly and are able to retain some of their bonding strength to intermediate temperatures.
g. Organic Binders : Organic binders include tars, pitches, or resins for use in reducing atmospheres where the carbon residuals impart bonding strength or act to inhibit alteration.

Biological Oxidation
The most commonly applied technology for final treatment of coke plant waste waters which have significant levels of phenol, cyanide, and ammonia, plus lesser concentrations of other organic compounds, primarily as a result of condensation from coke oven gases. The process consists of two stages : in an aeration basin, a mass of microorganisms in the form of suspended solids called an 'activated sludge' is supplied with oxygen, which enables it to destroy the biologically degradable contaminants in the wastewater. The treated water overflows to a clarifier, where the activated sludge is settled out to be recycled back to the aeration basin. The overflow water from the clarifier is discharged.

Bitumen Coating (Asphalt Coating)
An internal and / or external coating obtained either by dipping in a bath of molten asphaltic bitumen or by painting or dipping in a suitable asphaltic bitumen solution.

Bitumen Lining (Asphalt Lining)
An internal protection consisting of suitable bitumen, usually reinforced with inert mineral filler, applied hot by centrifugal means.

Bitumen Sheathing (Asphalt Sheathing)
An external protection consisting of bitumen reinforced with inert mineral filler which may be of a fibrous nature. The sheathing is applied hot.

Bituminous Solution
A paint made from bituminous materials dissolved in appropriate hydrocarbon solution.

Black Annealing
Annealing without any protective covering or using a controlled atmosphere. It is also termed as open annealing. Box annealing of ferrous alloy sheet, strip or wire.

Black Edges
The black colouration at the edges of annealed sheets and strips caused by oxidation or due to soot deposit.

Black Patches
Patches of scale left on sheet and strip surface due to unsatisfactory pickling.

Black Plate
1. Any steel that has not been coated – usually has gone through Tandem Mill (cold-rolled). Also defines a product, uncoated material in tin plate gauges. 2. 128 lb. (.0141 in) and lighter tin mill product which has not received any additional metallic coating during production. 3. A low carbon cold reduced steel intended for use in the uncoated state or for coating with tin and chromium.

Black Iron
Uncoated steel product.

Black Sheet or Strip
Hot-rolled sheet or strip that is not descaled.

Black Softened
Hot- or cold-rolled sheet and strip softened by black annealing, but not yet descaled (and usually refers to stainless variety).

Blank Holder
The device used to hold the blank to prevent wrinkling of the edges during pressing or drawing.

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 tall shaft-type furnace, with a vertical stack superimposed over a crucible-like hearth, lined with heat-resistant (refractory) bricks and used by integrated steel mills to smelt iron by reducing iron oxides present in ores and sinter into liquid hot metal by using coke as fuel and reducing agent. Its name comes from the blast of preheated air and gases blown from the bottom through water-cooled copper tuyeres and forced up through the iron ore, sinter, coke, and fluxes (limestone and dolomite) that load the furnace. Hot metal and slag are periodically tapped from bottom and gasses rising from the top are cleaned and used as fuel in the steel plant. Blast furnaces are rarely stopped but they can be slowed down or idled.

Blast Furnace Coke
The sized coke obtained from screening in the range of 25 mm to 80 mm which is suitable for charging in the blast furnaces.

Blast Furnace Gas
A by-product of the iron blast furnace. 2.5 to 3.5 ton of BF gas is generated per ton of the pig iron produced.

Blasting
A process of cleaning or preparing surfaces by high speed impact of abrasive particles, such as sand, chilled iron shot, or angular steel grit (generally called sand blasting, shot blasting or grit blasting).

Bleeding
1. Escape of liquid steel through the bursting of the shell of a partly solidified ingot due to build up of pressure inside the solidifying mass, or escape of liquid from the core of an ingot, withdrawn from the mould before it has solidified sufficiently. 2. A coating defect consisting of the migration of an ingredient to the surface of a coating, or a migration, which stains in an adjacent area. The term blooming is also a form of bleeding – usually associated with lubricants rather than pigments.

Blister
1. Coating defect consisting of the formation of bubbles in a coating, which appear as hemispherical elevations. The blisters are hollow, and are usually caused by entrapped air or solvent. 2. A raised spot on the surface on the surface of metal due to expansion of gas which causes a subsurface metal separation such as inclusions and small laminations.

Block Drawn
Wire drawn in coil on a block.

Block Off
1. Wooden separators which are used at both the bottom of a lift and between IPM’s (bundles) of a lift. 2. The act of placing 4x4s between the lifts in the piler’s box.

Blocking
A coating defect consisting of the adhesion of two adjoining coatings or materials. Usually this term refers to the coating on one side of coated plate being tacky or sticky and adhering to the adjacent sheet.

Bloom (1)
A semi-finished forged, rolled or continuously cast steel form whose cross-section is square or rectangular (excluding slab) and is generally more than 125 x 125mm (or equivalent cross-sectional area). This large cast steel shape is broken down in the mill to produce the familiar I-beams, H-beams and sheet piling. Reduction of a bloom to a much smaller cross-section results in formation of billets. 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.
Bloom (2)
A coating defect consisting of the migration of an ingredient, in the coating, to the surface of the cured film. Usually blooming refers to waxes or lubricants, which rise to the surface and cause a hazy appearance.

Blow Back
A coating defect consisting of a lower coating film weight on the bottom of the coated sheet caused by high velocity air in the oven. Blow back usually occurs with high solids coatings which have little solvent to evaporate and "set" the film.

Blow Hole (Gas Cavities)
Cavities in solid steel formed by entrapped gas bubbles during solidification.

Blowing Out
When a furnace has reached the end of its campaign (lining worn out), it is usually blown out except under most unusual circumstances. Or, if business conditions deteriorate to the extent production is no longer required, the decision may be made to blow out the furnace.

Blown Ingot
An ingot with pronounced blow holes.

Blown Metal
Liquid pig iron which has been subjected to blowing in the converter, as a result of which the iron is refined to the degree depending on requirement. Blown metal is made into steel by addition of elements as required.

Blue Annealing
Heating hot rolled ferrous sheet in an open furnace to a temperature within the transformation range then cooling in air to soften the metal. A bluish oxide surface layer is formed.

Blue Annealed Wire
Wire with scale free surface, but oxidised to a blue temper colour during annealing.

Blue Billy (Purple Ore)
The iron oxide residue from the manufacture of sulphuric acid from iron pyrites containing approximately 50% iron. It is used for fettling the puddling furnace.

Blued Edges
Blue or bluish-black oxidation colouration at the edges of sheets and strips arising during heat treatment in the absence of any protective medium.

Blush
A coating defect consisting of the whitening of a cured film which results in a translucent or opaque appearance with accompanying loss of gloss. Blushing usually occurs during the pasteurization or steam processing of films which are undercured or water sensitive.

Boiler Tubes (Smoke Tubes)
Tubes which form part of the heating surface of a boiler, as distinct from superheater tubes. The tubes may contain water and be surrounded by the furnace gases as in a water tube boiler, or they may act as flues and be surrounded by water as in smoke tube boiler.

Bolster
A dovetailed block of steel which rests on the base block of the hammer into which the bottom die is keyed.

Bonderizing
Treating cold rolled or galvanized steel surfaces with phosphate to improve paint-adherence.

Bonderized Coating
A thin film of phosphate pretreatment applied to a steel surface (bare or zinc coated) to enhance paintability.

Boss
A projection on the surface of a forging.

Bottling
Reducing the diameter at the end of a hollow forging to form a neck.

Bottom Blowing
Injection of oxygen, singularly, with additives (such as pulverized lime) or in addition to hydrocarbon fuels (such as natural gas, pulverized coke or fuel oil), all routed in the same manner to initiate reactions in the bath during oxygen steelmaking.

Bottom Casting (Trumpet Casting, Uphill Casting)
Simultaneous casting of a number of ingots by pouring the metal into a central refractory-lined tube or trumpet, whence it flows through refractory runners into the bottom of the moulds.

Bottom Fash (Bottom Flash, Bottom Fin)
A layer of metal in the space between the base of the mould and the bottom plate which is attached to the ingot. Similarly, a layer of metal may be formed at the top, in the space between the mould and the refractory lined hot top, the layer of metal formed being called top flash.

Bottom Plate (Bottom Stool)
A cast iron plate of suitable size, on which the bottom of the mould (which is open at both ends) sits. This plate may be recessed or refractory lined.

Bottom Splash (Bottom Shell)
The splash of metal solidifying on the bottom portion of a mould, and later engulfed in the rising column of liquid steel, and arises from the impact of the liquid steel on the bottom plate in initial stages of teeming.

Bottom Stirring
Injection of essentially inert gases into the bottom of the BOF vessel, penetrating the bottom shell and the bottom refractory lining, under the molten bath, to agitate the molten masses for such purposes as homogeneity of the melt after introducing additions in the furnace and improving the interaction between the steel bath and the slag. There is usually no direct chemical reaction associated with bottom stirring. The gas injection is either by means of refractory material porous plugs embedded in the bottom lining, or by means of tuyeres, penetrating the bottom lining.

Box Annealing (Close Annealing)
A process of annealing a ferrous alloy in a suitable closed metal container, with or without packing material, in order to minimize oxidation. The charge is usually heated slowly to a temperature below the transformation range, but sometimes above or within it, and is then cooled slowly.

Bow
The greatest deviation from a straight line along a longitudinal edge in a sheet or strip.

Box Annealing
Annealing of a metal or alloy in a sealed container under condition that minimise oxidation. See black annealing also.

Brake Press Bending
An operation which produces various degree bends when fabricating parts from steel.

Breakage
Cracks or separation of the steel.

Breaker
Uncoiler rolls through which the strip passes; composed of a mandrel and leveling rolls which unwind the strip prior to processing through the Pickler. Breaker rolls assist in breaking up the Hot Mill surface scale.

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 and cause considerable damage to the furnace and surrounding auxiliaries. The term is also used in continuous casting when the solidified outer shell breaks-out resulting in liquid steel flowing-out and spreading over the casting machine, jeopardising the entire casting operation.

Breeze Coke
Smallest fraction of coke, less than 10 mm in size.

Bridging
See Slips.

Bridle Unit
A three-roll cluster used to control line tension at strategic locations on the line.

Bright Annealing
Annealing in a protective medium to prevent discoloration of the bright surface.

Bright Annealed Wire
Wire which has been annealed in a controlled atmosphere to prevent surface oxidation.

Bright Bar or Wire
Bar or wire with a bright finish obtained by cold drawing, machining, grinding etc.

Bright Ground
Bar or wire ground between abrasive wheels which give a bright finish to the material.

Bright Machined
Material which has been turned, ground, shaped or milled to size and finished with a smooth bright surface.

Bright Turned Rounds
a. Round hot rolled material which has been reduced in size by centreless turning and finished with a smooth bright surface
b. Round hot rolled material which has been turned between centres and finally finished. Turned material is generally cold rolled to remove tool marks.

Brinell Hardness Test
A test for determining the hardness of a material by forcing a hard steel or carbide ball of specified diameter into it under a specified load. The result is expressed as the Brinell hardness number.

Briquette Blending
Using non-coking or poorly coking coals by partially briquetting them with coking coals (and binder i.e. tar or pitch) to produce high-strength coke.

Brite
1. Regular galvanize coating (not minimized spangle or JP). 2. Rolls that have no grit; smooth finish on surface of steel.

Brittle Fracture
Separation of a solid accompanied by little or no macroscopic plastic deformation. Typically, brittle fracture occurs by rapid crack propagation with less expenditure of energy than for ductile fracture.

Brittle Inter-metallic Layer
An iron-zinc alloy layer formed between the steel substrate and the free zinc of galvanized coatings.

Brittleness
Tendency to fracture without any visible sign of appreciable deformation.

Broken Backs
A band of traverse cracks along a drawn wire.

Bruise
A mark transferred to the strip surface from a defective process roll. Similar to dent or punchmark.

BSO
See Butyl Stearate.

Buckling
A compression phenomenon that occurs when, after some critical level of load, a bulge, bend, bow, kink, or other wavy condition is produced in a beam, column, plate, bar, or sheet product form.

Build Up Coil
A coil made by putting together two or more coils to make one max coil or one shippable coil.

Bundle
Specific number of sheets which equals 1 unit of production. Number is determined by multiplying sheets/Packages/Bundle. For example, an order calls for 112 sheets/package according to the maximum height allowed for a lift. Therefore, multiplying 15 packages X 112 sheets = 1680 sheets/bundle.

Burdening
The regulation of the proportion of ore, pellets, sinter, flux, coke and miscellaneous materials charged into the blast furnace. Essential to keep the operation of the furnace at maximum efficiency and to control the hot metal composition.

Burden Ratio
In blast furnace, the ratio of iron-bearing materials per charge to the weight of coke.

Burned Steel
A defect on the surface of the ingots, usually on their corners, as a result of flame infringement as they are heated in the soaking pits.

Burning
(1) During austenitising, permanent damage of a metal or alloy by heating to cause incipient melting or intergranular oxidation.
(2) During subcritical annealing, particularly in continuous annealing, production of a severely decarburised and grain coarsened surface layer that results to excessively high temperature.
(3) In grinding, sufficient heating of the workpiece to cause discoloration or to change the microstructure by tempering or hardening.

Burnt Edges
Broken edges occurring during hot-rolling and caused by overheating or burning.

Burnt Rubber
Small or large black spots that generally show up on surface and are generally caused by pickling steel too hot.

Burr (Fash, Flash)
The very subtle ridge on the edge of strip steel left by cutting operations such as slitting, trimming, shearing, sawing or blanking. For example, as a steel processor trims the sides of the sheet steel parallel or cuts a sheet of steel into strips, its edges will bend with the direction of the cut (see Edge Rolling).

Burr Mashers
Devices used to remove build up on edge of strip after the slitting process.

Burst Edges
Edges of sheet or strip ruptured due to excessive cold rolling.

Bushelling
1. Steel 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.
2. Compacting wrought iron turnings, borings and scrap into a bloom or slab by heating to a welding temperature and forging.

Butterfly
Rotating disc-type valve which moves 90o from the closed position to the fully open position. Normally used to stop or control the flow through a line, the butterfly regulates steam on the plant service line.

Butt Weld
Weld made to join two strip ends set against each other.

Butt Welding
Joining two edges or ends by placing one against the other and welding them.

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.

Butyl Stearate (BSO)
A lubricant applied on electrolytic chromium coated steel.

By Coil
Selling term which refers to product sold in the form of a coil vs. cut plate. "Bi Coil" is also used in production to refer to coils vs. cut plate.

By-Product Process of Coke Making
In this process, air is excluded from the coking chambers, and the necessary heat for distillation of coal is supplied from external combustion of some of the gas recovered from the coking process (or, in some instances, cleaned blast furnace gas or a mixture of coke oven and blast furnace gas).


Source:worldofsteel.com

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