Dam
A refractory block in the blast furnace cast house which holds back the hot metal until the depth of metal in the trough is sufficient (about 300mm) to contact the bottom of a refractory skimmer block.
Dead Steel
A steel which is quite in the mould after the teeming is completed. This steel is fully deoxidized.
Deburris
Horizontal knife used to remove burrs after slitting.
Decarburisation
Loss of carbon from the surface layer of a carbon-containing alloy usually during heating, hot working or heat treatment due to reaction with one or more chemical substances in a medium that contacts the surface.
Deep Drawing
The fabrication process of flat rolled steel to make drawn parts. The part is mechanically formed through or in a die. The blank diameter is reduced; the blank contracts circumferentially as it is drawn radially inward. (See Deep Drawing Applications).
Deep Etching
Macroetching specially for steel to determine the overall character of the material that is the presence of imperfections such as seams, forgings, bursts, shrinkage-void remnants, cracks and coring.
Deep Drawing Applications
Parts/applications that require deep drawing in their fabrication. Examples are motor shells, fenders, quarter panels, door panels.
Deep Drawing Steel
A high quality low carbon steel possessing high ductility, desirable grain size, etc. which permits deep drawing.
Defect
- Anything that renders the steel unfit for the specific use for which it was ordered. What is defective for one customer may be prime steel for another. 2. A variety of quality problems in a coil. Examples are punch marks, roll marks, oil spots, and scratches.
Deflector Roll
A roll used to change the direction of the strip.
Deformed Bar
Concrete reinforcing bars in which the surface is provided with lugs or protrusions )called deformations) which inhibit longitudinal movement of the bars relative to the surrounding concrete. The surface deformations are hot formed in the final roll pass by passing the bars between rolls having patterns cut into them so that the surfaces of the bars are forced into the depressions in the rolls to form characteristic deformations.
Defrazing (Frazing)
Removing the uneven edges at the ends of welded tube.
Degas Heat
A heat of degas steel is a heat that is produced to extremely low carbon levels through vacuum degassing.
Degassing
Liquid steel absorbs gases from the atmosphere and from the materials used in the steel making process, which cause embrittleness, voids, inclusions, and other undesirable phenomena in the steel after it solidifies. Degassing aims to remove the gases (chiefly hydrogen and oxygen).
Delay Code
A four-character code used to identify the type and reason for a delay.
Delivery End
The exit end of the line.
Delivery Tail End
The outside lap of the produced coil on the delivery reel.
Delta Iron
Solid phase of iron that is stable from 1400 to 1539 0 C and possesses the body centred cubic lattice.
Demineralized Water
City water which is circulated through a series of three demineralizing filters to soften it and remove residuals. It is then delivered to a storage tank for use in overflowing the superheater elements and headers on the boiler during hydrostatic tests. Filling the superheaters with demineralized water prevents the raw water used in a hydrostatic test from entering the superheaters where it could cause corrosion problems
Dendrite
A crystal with a treelike branching pattern. It is most evident in cast metals slowly cooled through the solidification range.
Deoxidation
Reduction of oxygen content of the finished liquid steel by adding deoxydizers in the bath, in ladles or in the moulds. Deoxidation is the last stage of steel making. In all types of steel making processes, the steel bath at the time of tapping contains 400 to 800 ppm O. Deoxidation is carried out during tapping by adding into the tap-ladle appropriate amounts of ferromanganese, ferrosilicon and / or aluminum / silicon / titanium etc.
Deoxidizers
Substance having a high affinity for oxygen used for finishing steel.
Dephosphorisation
The process of reduction of phosphorus to the desired extent in steel making processes.
Depletion
Selective removal of one component of an alloy usually from the surface or preferentially from grain boundary regions.
Deseaming (Scarfing)
The removal of surface defects from ingots or semi-finished products by an oxy-gas flame.
Descaling
The process of removing scale from the surface of hot-worked or heat-treated product by pickling, shot-blasting etc. Also, removal of scale during hot working by the application of steam under high pressure, water, coal dust, brushwood, oil, etc. Scale forms most readily when the steel is hot by union of oxygen with iron. Common methods of descaling are: (1) crack the scale by use of roughened rolls and remove by a forceful water spray, (2) throw salt or wet sand or wet burlap on the steel just previous to its passage through the rolls.
Deseaming
The removal of surface defects from ingots or semi-finished products by an oxy-gas flame.
Desiliconization
Removal of silicon from the hot metal prior to the oxygen converter process. Silicon removal is beneficial to the converter to reduce the chemical attack on the basic refractory lining and to allow the use of only minimal amounts of slag-making fluxes, thereby maximizing process yield.
Desulfurization
What 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.
Why Sulfur enters the steel from the coke in the blast furnace smelting operation, and there is little the steel maker can do to reduce its presence. Because excess sulfur in the steel impedes its welding and forming characteristics, the mill must add this step to the steel making process.
Dezincification
Corrosion in which zinc is selectively leached from zinc-containing alloys. Most commonly found in copper-zinc alloys containing less than 85% copper after extended service in water containing dissolved oxygen.
Die
A tool having a prepared hole through which tubes are passed in the drawing or push bench process.
Die Lines
Longitudinal lines on the outer surface of a drawn tube caused by localized seizure between the tube and the die.
Die Mark
Scratch marks made during drawing due to poor condition of dies or gritty material being drawn in the die along with the wire.
Die Rolling
The process of rolling a string of blanks, each of which has varying cross-sectional area produced by heavy reductions, and specified center to center length. When sheared to length, the blanks are of identical shape. Products such as automobile axles and crank shafts are produced satisfactorily by die rolling. The blanks are rolled with or without finishing, depending upon the particular product section.
Dies (Galvanize)
Air pressure devices in the Sheet Mill which, depending on distance from coil, determine coating thickness by removing excess metal from the strip; the farther the die is from the steel, the heavier the coating – also called “knives” on this line.
Die Wear
The erosion of the die surfaces caused by the flow of plastic metal over them.
Differential Coatings
Coatings on flat rolled products whereby the thickness of the coating on the one side is heavier than the other side.
Dimensional Tolerance
A range by which a product’s width and gauge can deviate from those ordered and still meet the order’s requirements. (Also See Commercial Tolerance)
Dimple
The jet impact zone caused by the impingement of oxygen during lancing operation in steel-making. The oxidation reactions occur in this zone.
Dings
Kinks on sheet surface.
Direct Casting (Top Pouring)
Direct pouring of ingots or castings from ladle, that is, without using any refractory reservoir or tundish, in between.
Direct Processes
All the methods whereby low-carbon wrought iron can be produced directly from the ore are referred to as direct processes.
Direct Reduced Iron (DRI)
What A processed iron ore that is iron-rich enough to be used as a scrap substitute in electric furnace steel making.
Why As mini-mills expand their product abilities to sheet steel, they require much higher grades of scrap to approach integrated mill quality. Enabling the mini-mills to use iron ore without the blast furnace, DRI can serve as a low residual raw material and alleviate the mini-mills’ dependence on cleaner, higher-priced scrap.
How The impurities in the crushed iron ore are driven off through the use of massive amounts of natural gas. While the result is 97% pure iron (compared with blast furnace hot metal, which, because it is saturated with carbon, is only 93% iron), DRI is only economically feasible in regions where natural gas is attractively priced.
Direct Reduction Processes
The processes that produce iron by reduction of iron ore below the melting point of the iron produced.
Direct Smelting Processes
The processes that produce a molten product (similar to blast furnace hot metal) directly from ore. Direct Steel
Making Processes
The processes that produce liquid steel directly from ore.
Discard
Those portions corresponding to the top and bottom of the ingot which are removed to ensure that the remainder of the material is of satisfactory quality. Also, defective material produced in rolling or forging, to be cut off from one or both ends of the semi-finished or finished product.
Dishing
Forming a cup or depression in a forging
Divided Mould
In this method, a permanent divider is used in the center of the mould, which permits the casting of two narrow slabs simultaneously on a single strand using common containment and withdrawal units. This increases the productivity of a casting machine.
Dog Leg
Bow-legged strip, that is, a strip which has been curved in opposite directions in two adjoining portions.
Dolomite
Naturally occurring mineral consisting mainly of calcium-magnesium carbonate (Ca, Mg) CO3 used as a flux in steel plants or a refractory in basic steel making furnaces after calcination (high temperature firing or dead burning). High purity dolomite is greater than 97% CaO + MgO and 0.5-3% impurities (mostly silica, iron oxide and alumina). Dolomite is also used to add magnesium oxide to the sinter.
Dormant Scrap
Comprises obsolete, worn out or broken products of consuming industries. This type of scrap, because of its miscellaneous nature, requires careful sorting and classification to prevent the contamination of steel in the furnace with unwanted chemical elements from alloys that may be present in some of the scrap.
Doubles
Sheets hot-rolled after doubling.
Doubling
Folding a sheet or sheet-pack on itself, about the middle, before rolling further.
Double (Cold) Reduced (DR)
- Material that has been cold reduced in thickness twice. 2. Plate given a second major cold reduction following annealing. Double reduced products are relatively hard, have limited ductility, and highly directional mechanical properties.
Double Skin (Curtaining)
A secondary layer of steel on ingot surface, arising from overflow of molten metal from interior to the space between the solidified ingot face and mould wall. It is also formed by splashings.
Dozzle
A hollow refractory brick preheated to high temperature and used to provide a feeder head for small ingots.
DQ
“Draw quality” = more flexible grade of steel.
Flat-rolled products produced from either deep drawing rimmed steel or extra deep drawing aluminum killed steels. Special rolling and processing operations aid in producing a product, which can stand extreme pressing, drawing or forming, etc., without creating defects.
Draft or Draught
The amount of reduction in the cross-sectional area of a tube during rolling or drawing; often in drawing, it might refer only to reduction in thickness.
Drawn
Mechanically formed by tension through or in a die.
Drawn & Ironed (D&I)
A process primarily used to manufacture two-piece beer or carbonated beverage can bodies, although some canned food product is packaged in steel D&I can bodies. An appropriately sized circular disk is drawn into a cup to approximately the finished can diameter. The side wall height is created by forcing the cup through a series of rings, ironing the metal thinner than the starting material thickness. Can bodies are coated with organic lacquers after forming.
Drawn-Over-Mandrel
A procedure for producing specialty tubing using a draw bench 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 include automotive applications and hydraulic cylinders.
Drifting
Expanding a forging by driving in a tapered tool.
Drop Forging
An article produced by hot working the metal between closed dies by means of a falling weight as in a drop hammer, the operation involving a modification of both the form and section of the stock from which the forging is produced.
Draw-Redraw (DRD)
Process for making two-piece cans in which a circular blank is drawn into a die to form a shallow cup and then is redrawn on a second or third die to produce a can body of the desired dimensions. Plate is coated prior to the forming process.
Draw-Thin-Redraw (DTR)
An enhancement of the DRD process for making two-piece can body utilizing high tensile TFS that has an organic polymeric coating applied prior to the forming operations. The patented DTR process is a means of subjecting the coated feedstock to forming strains such that the metal and coating avoid compacting and subsequent sidewall burnishing, thus enhancing the integrity of the organic coating. The resultant sidewall is thinned during the drawing and redrawing operations, thus facilitating the specified can body dimensions using a smaller starting blank size than that required for DRD.
Dressing
Removing surface defects or cleaning and / or reconditioning of castings, ingot, bloom or slab by chipping, deseaming, scarfing, grinding or other methods.
Dressing of Coil
Eliminating any damage or defects from outer or inner diameter of coil in preparation for shipping.
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.
Dross
Sediment which settles in bottom of the zinc pot on the galvanize line. Also top dross, which floats on surface of pot and is skimmed off. A different type of dross also occurs on the top of the zinc pot, which is skimmed off on a regular time frame.
Dryer
Dries the strip after a rinsing process.
Dry Film Weight
Dry coating film weight is normally calculated in gm/m² or mg/in². Accurate control of dry film weight is essential to ensure that the coating material will possess its intended properties of physical and chemical resistance.
Ductile Fracture
Fracture characterized by tearing of metal accompanied by appreciable gross plastic deformation and expenditure of considerable energy.
Ductility
A qualitative, subjective property of material that indicates the extent to which it can be deformed without fracture in metal working operations such as rolling, extrusion, fabrication, etc. fracture at room temperature. It is generally expressed as total permanent strain prior to fracture, measured as elongation or reduction of area during tensile testing.
Dummy
The part of die used for rough forming the stock before the final forging operation.
Dummy Hammer
A mechanically operated hammer used for drawing out or shaping the material prior to the final forging
Dumping
Dumping occurs when imported merchandise is sold in, or for export to, the domestic market at less than the normal value of the merchandise, i.e., a price which is less than the price at which identical or similar merchandise is sold in the comparison market, the home market (market of exporting country) or third-country market (market used as proxy for home market in cases where home market cannot be used). The normal value of the merchandise cannot be below the cost of production.
Dumping Margin
The amount by which the normal value exceeds the export price or constructed export price of the subject merchandise.
Duplex
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.
Duplex Process
Steel making by a combination of two processes, such as Bessemer and open hearth processes or open hearth and electric processes, the popular combination being one using acid Bessemer convertor and basic open hearth furnace.
Ears
The wavy projections formed in deep-drawing which normally occur in geometric positions either at 45% or at 0% and 90% to the direction of rolling. These are caused by directional properties in the sheet.
Easy Open End
A convenience feature can end designed to be opened by utilizing an integral tab opener to tear the container lid along a tear line formed in the lid. The end is designed so that after the container is opened, safe edges remain on the removable panel portion torn off from the lid body and on the rim remaining on the container. This is accomplished by shielding the residual tear line metal with multi-layer metal folds.
Eccentricity
Lack of coincidence of the centre of the bore of a tube with that of the outside circumference, resulting in variation in wall thickness.
ECCS
See Electrolytic Chromium Coated Sheets.
Eddy Current Methods
Used to measure physical and mechanical parameters and for the detection of surface imperfections in steel products. Eddy currents are so named because their paths often resemble the circular eddies in water. The eddy current method measures the electromagnetic interaction between a transducer or test coil and the part being inspected. By this interaction such physical parameters as the hardness, steel grade, and case depth can be inferred. In addition, cladding thickness, foil thickness, and the presence of surface or subsurface imperfections may be indicated.
Edge Break
A condition caused by an uneven roll surface. It is seen on the edges of a coil, not across the full width of the coil.
Edge Buckle
Edge buckle is similar to center buckle except that the condition occurs in one, or both edges, of the strip and is generally confined to a narrow portion of the width.
Edge Buildup
Condition that results when burred or damaged plate causes the edge of the coil to be higher in coating than the center of the coil.
Edger
- Or edging rolls, are used to give a universal or rolled edge to the product. 2. The part of die used to distribute the metal in the proposition necessary to fill the die impression.
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 manipulate.
Edging
The application of rolls to the edges of a rectangular section, for example, slab, plate, strip and flat, with the object of controlling width and giving a smooth edge of desired contour during the rolling process. Rounding by forging an upended disc or cheese to form a blank.
Edge Wave
A condition in the band of steel where the edges (in the direction of rolling) are longer than the center.
Elastic Deformation
Stretching of the material below the point at which a permanent “set” takes place. That is, in the range where the metal acts spring-like or elastic.
Electric Arc Furnace (EAF)
Steel making furnace where scrap is generally 100% of the charge. Heat for melting and refining of steel is supplied from electricity that arcs between the electrodes (usually graphite) or between electrode and the metal bath. When the arc is between the electrodes, the process is termed as the indirect arc process and when it is between the metal and the electrode, it is termed as the direct arc process. 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 Process
A process of steel making wherein the source of fuel is electrical energy, that is, heat from electric arc or induced eddy currents, and the process is termed accordingly as electric arc process or induction process.
Electrical Sheet Steel
A group of steels made by electric process (silicon or aluminium alloyed) and used for the construction of magnetic cores of electrical equipment, because of their low watt-loss properties. They are divided into two general classifications, (I) oriented steels, and (2) non-oriented steels. The oriented steels are given mill treatments designed to yield exceptionally good magnetic properties in the rolling, or lengthwise, direction of the steel. Non-oriented grades are made with a mill treatment that yields a grain structure, or texture, of a random nature and, therefore, the magnetic properties in the rolling direction of the steel are not significantly better than those in the transverse direction.
Electric Reduction Furnace
Used for smelting ores in the production of ferroalloys, such as ferro-manganese, ferro-silicon, and ferro-chromium. These furnaces differ from the steel-making furnaces in that production is continuous, as in a blast furnace; the charge is placed in the furnace at the top and the molten product tapped near the bottom. Electric furnaces are also used in the smelting of iron ore.
Electric Resistance Welded (ERW) Pipe
Pipe made from strips of hot-rolled steel which are is formed into tubular shape by passing through forming rolls and welded by passing a heavy current across the longitudinal joint. While seamless pipe is traditionally stronger and more expensive than comparable ERW pipe, ERW technology is improving and the technique now accounts for approximately 48% of OCTG shipments by tonnage. Generally used by oil or gas companies.
Electric Soaking Pits
Developed to meet special requirements, such as control of scaling and the maintenance of controlled atmospheres during the heating of stainless-steel and alloy-steel ingots.
Electro Discharge Texturing
Developed to meet special requirements, such as control of scaling and the maintenance of controlled atmospheres during the heating of stainless-steel and alloy-steel ingots.
Electro-galvanizing Process
A cold-coating electroplating process in which the furnaces, galvanizing pot, and the cooling tower of the hot-dip process are replaced by a series of electrolytic cells through which steel passes. This process, unlike the hot-dip process, does not influence the mechanical properties of the sheet steel and provides a more uniform coating.
Electrolytic extraction
Removal of phases by using an electrolytic cell containing an electrolyte that preferentially dissolves the metal matrix.
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 Polishing
An electromechanical polishing process in which the metal to be polished is made the anode in an electrolytic cell where preferential dissolution at high points in the surface topography produces a specularly reflective surface.
Electrolytic Tin Coated Sheets (ETCS)
Cold rolled sheet 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 electro-deposited. 2. Black plate coated with Tin (Sn) electron deposition.
Electroplating
A batch process used to produce a zinc coating on manufactured articles. These may be functional (for corrosion protection) or decorative coatings. Electric current is used to force the deposition of negatively charged zinc ions from an acid solution onto the positively charged cathode, which is the article to be coated. Produces thin coatings generally less than 10 um (0.4 mils) thick.
Electro-galvanizing
A continuous process used to produce a zinc coating on steel sheet by electroplating. Both sulfuric or hydrochloric acid solutions are used. The most common method uses sulfuric acid with insoluble anodes. Produces thin coatings generally less than 10 um (0.4 mils) thick.
Electro-magnetic Stirring
This process, carried-out during solidification of liquid steel in a billet or bloom caster, imparts the following potential benefits to liquid steel :
- Internal quality (reduced segregation, cracking and porosity) through a preferred solidification structure.
- Sub-surface and internal cleanliness through a modified metal flow pattern.
- Reduced criticality of casting parameters (temperature and casting speed)
- Increased productivity through increased casting speeds.
Electroplating
This process is an old art, practised not only to protect the base metal from corrosion but also for decorative purposes and, more recently, to protect the base metal from wear by friction or abrasion. Metals used for coatings include cadmium, chromium, copper, gold, tin, lead, nickel, silver and zinc, and alloys such as brass, bronze and lead-tins as well as cobalt-tungsten, tungsten-nickel, nickel-zinc and cadmium-tin alloys
Electro-slag Remelting (ESR) Process
In this secondary steel making process, one or more steel electrodes of about the desired chemical composition are drip-melted through molten slag into a water-cooled copper mould at atmospheric pressure. The remelting rate for this process is somewhat greater than that for the Vacuum Arc Remelting (VAR) process, otherwise the two processes are similar. The ESR process cannot eliminate hydrogen as the VAR process is able to do, but it has the following capabilities :
- Multiple electrodes can be melted into a single mould.
- Spacing between mould wall and electrodes is not critical.
- Ingot surface quality is excellent, requiring little or no conditioning.
- Steel can be desulphurized to 0.002 per cent sulphur content.
- Bound, square and rectangular shaped ingots can be produced.
- Larger size and weight ingots can be produced.
Electro-stripping
A process by which the thickness of alloy deposited on a strip can be determined.
Electro-tinning
Tin coating by electro-deposition. This gives better uniformity and close control of tin-coating weight obtainable, resulting in saving of tin.
Elevator Furnaces
Car-bottom furnaces where the car is rolled under the furnace shell and then raised into the furnace by a motor-driven lifting mechanism.
Elongation
- Total plastic strain before fracture, measured as a percent or axial strain during tensile testing. 2. This term is also used on orders specifying tensile test on which a minimum elongation between give points and distances has to be met. This elongation is expressed as percent of stretch over a given length, i. e. 25% elongation in 2 inches.
Embedded Abrasive
Fragments of abrasive particles forced into the surface of workpiece during grinding, abrasion or polishing.
Embossing
A coating defect consisting of the crawling or dewetting condition where the wet film recedes and forms a raised (in relief) impression.
Enamel
Organic material, which is applied in a film to protect or decorate aluminum, tinplate, black plate or paper.
Endurance
The capacity of a material to withstand repeated application of stress.
Epoxy Amino
Clear thermosetting coating with a combination epoxy resin and amino resin to give adhesion, flexibility and toughness. They offer good chemical and solvent resistance.
Epoxy Phenolic
Physical blends of epoxy and phenolic resins. Gold thermosetting coating with a combination of epoxy resin and amino resin to give adhesion, flexibility and toughness. They offer good chemical and solvent resistance.
Epsilon
Designation generally assigned to intermetallic, metal-metalloid and metal non-metallic compounds found in ferrous alloy systems.
Erosion
Progressive loss of original material from a solid surface due to mechanical interaction between that surface and a fluid, a multi-component fluid, or impinging liquid or solid particles.
Etching
In metallography, the process of revealing structural details by the preferential attack of reagents on a metal surface.
Etch Cracks
Shallow cracks in hardened steel containing high residual surface stresses, produced by etching in an embrittling acid.
ETCS
See Electrolytic Tin Coated Sheets.
ETP
See Electrolytic Tin Plate.
Exact Length
Material cut to specified length and agreed tolerance.
Exit End
The delivery end of the line.
Exit Reel (Delivery Reel or Prime Reel)
Reel used to wind the strip after the side trimming process.
Extra Deep Drawing Steel
A superior quality low carbon deep drawing steel.
Extrusion
Hot Extrusion : Consists of enclosing a piece of metal, heated to forging temperature, in a chamber called a ‘container’ and having a die at one end with an opening of the shape of the desired finished section, and applying pressure to the metal through the opposite end of the container. The metal is forced through the opening, the shape of which it assumes in cross-section as the metal flows plastically under the great used.
Cold Extrusion : It is carried out in a manner similar to the hot-extrusion process, with two main exceptions : (1) The steel is at room temperature, and (2) the surface of the piece is treated by some chemical process such as bonderizing to assist in reducing the friction between the steel and the container wall and die, in conjunction with special lubricants
Extrusion Billet
A short length of billet or hot-rolled bar, either solid or with a central hole.
Eye Bands
Metal bands wrapped through the center or “eye” of the coil to prevent it from uncoiling and to hold strip mults together.
Eyeholing
A coating defect, similar to cratering, but with exposed metal in the void.
Eye of Coil
The centre of the coil as wound.
Fabricator
A producer of intermediate products that does not also produce primary metal. For example, a rebar (see Reinforcing Bar) fabricator purchases rebar and processes the material to the specifications of a particular construction project.
Fading
A coating defect consisting of the condition in a colored coating where the color, either transparent or opaque, appears to get lighter or bleached out. Heat, light, or chemical exposure usually causes fading.
Fanning
Curtailing the operation of blast furnace by reducing the quantity of wind being blown (to less than 20-25% of normal). This is done when the full productive capacity of the furnace is not required for a period of time. This technique is used for emergency situations or short periods only (for a few hours at a stretch).
Fash (Top Fash, Top Flash, Burr Flash)
Sharp and ragged edges left after shearing or sawing.
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
The phenomenon leading to fracture under repeated or fluctuating stresses having a maximum value less than the ultimate tensile strength of the material. Fatigue failure generally occurs at loads which applied statically produce little perceptible effect. Fatigue fractures are progressive, beginning as minute cracks that grow under the action of the fluctuating stess.
Fatigue Failure
Failure that occurs when a specimen undergoing fatigue completely fractures into two parts or has softened or been otherwise significantly reduced in stiffness by thermal heating or cracking.
Feather Edge
A sharp reduction in gauge on the edge of a band which is caused by grooves worn in rolls due to extensive rolling of the same width material. This is done for coating control on edge. The gauge variations on a feathered edge generally does not extend in from the edge more than one inch.
Feeder Head (Hot Top Sink Head)
A refractory lined receptacle, placed on the mould top or built into the ingot mould to reduce the shrinkage cavity (pipe) by keeping the metal in liquid state longer at the top. This arrangement confines the shrinkage cavity to the feeder head.
Feed Pipe
A pipe through which water is forced into a boiler.
Feedstock
Any raw material.
Ferrite
A solid solution of one or more elements in body centred cubic iron. In plane carbon steels, the interstitial solid solutions of carbon in a – iron
Ferritic
The second-largest class of stainless steel, constituting approximately 25% of stainless production. 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).
Ferrite Grain Size
The grain size of the ferritic matrix of a steel.
Ferritic Anneal
The process of producing a predominantly ferritic matrix in a ferrous alloy through an appropriate heat treatment.
Ferroalloy
A metal product commonly used as a raw material feed in steel making, usually containing iron and other metals, to aid various stages of the steel making process such as deoxidation, desulfurization, adding strength or for introducing such elements in steel. Examples: ferrochrome, ferromanganese, and ferrosilicon, silicon manganese etc.
Ferrochrome
An alloy of iron and chromium with up to 72% chromium. Ferrochrome is commonly used as a raw material in the making of stainless steel.
Ferrous
Metals that consist primarily of iron.
Ferrous Alloy
See Alloy Steel.
Fettling
Repairing the furnace banks and bottom immediately after a heat is tapped.
Fibrous Fracture
A gray and amorphous fracture that results when a metal is sufficiently ductile for the crystals to elongate before fracture occurs. When a fibrous fracture is obtained in an impact test, it may be regarded as definite evidence of toughness of the metal.
Fibrous structure
(1) In forgings, a structure revealed as laminations, not necessarily detremental on an etched section of or as a ropy appearance on a fracture
(2) In wrought iron, a structure consisting of slag fibers embedded in ferrite
(3) In rolled steel plate stocks, a uniform lamination free fine-grained structure on a fracture surface.
File Hardness
Hardness as determined by the use of a file of standardized hardness on the assumption that a material that cannot be cut with the file is as hard as, or harder than, the file. Files covering a range of hardness may be employed.
Fin (Overfill, Flash)
Solidified metallic strip projecting out at right angles from ingot surface and caused by seepage of liquid metal through a longitudinal crack in the mould, or in the mould joint in case of split mould. Or, a protruding rib of metal running longitudinally along a rolled product, as results from overfilling a pass.
Fin Crack (Longitudinal Crack)
Crack in the ingot associated with the formation of fin and the resulting obstruction during contraction while cooling.
Finish
The surface appearance of steel after final treatment.
Finishes
The texture of the steel surface which is determined by the grit on the rolls (See Shot Blast Roll Finish) or by the grind on the rolls in the case of bright finish (See Ground Roll Finish).
Finishing Facilities
The portion of the steel making complex that processes semi-finished steel (slabs or billets) into forms that can be used by others. Finishing operations can include rolling mills, pickle lines, tandem mills, annealing facilities, and temper mills.
Finishings
Finishing additions of ferro-alloys, deoxidizers and/or carburizers (for example, coke) which are made to liquid steel, usually in ladle, and at times, partly in the furnace, so as to bring the liquid steel to the desired specification.
Finishing Stand
The last stand in a rolling mill, which determines the surface finish and final gauge.
Finishing Temperature
The temperature at which hot mechanical working of metal is completed.
Fireclay
A refractory material, essentially hydrated aluminium silicate in composition, having a high fusion point used in the manufacture of refractory bricks or mortar.
Fire Cracks
An irregular pattern of lines on the surface of a sheet caused by rolling with a fire cracked roll. Fire cracks will develop when a roll is not properly cooled.
Fish Eyes
A coating defect consisting of the undissolved particles in the coating usually surrounded by a circular crater. The particles are usually resinous and are raised up from the cured surface with the appearance of the eye of a fish.
Fish Tail
The V-shaped cavity which may develop on the tail-end of the strip from the hot strip mill.
Flakes
Small, discontinuous, internal ruptures attributed to stresses produced by localized transformation and hydrogen-solubility effects during cooling after hot working that usually occur some distance away from the end of a piece and often midway from the surface to the center of a section. In fracture surfaces, flakes appear as bright, silvery areas with a coarse texture. In deep acid-etched transverse sections, they appear as discontinuities. It is generally considered that hydrogen dissolved in the molten steel makes it more susceptible to flakes and that proper retardation of cooling from forging or rolling temperatures effectively will prevent their formation. Also termed hairline cracks and shatter cracks.
Flash Burn
A defect made by contact rolls when an arc is passed through the strip. Generally on lighter baseweight. (DR coils)
Flashing
A coating defect consisting of the uneven, random distribution of a coating on coated substrate. A variation in the color of a coating which is due to variations of the film weight. A coating defect consisting of the flame weight fluctuation is caused by disproportionate amount of coating transferring from the application roll.
Flash Stain
A stain that occurs in the rinse tanks when the line has stopped. It appears blue, green, or black.
Flat Coil
Coil that has a collapsed center.
Flatness
The absence of any gap or clearance when a strip is placed, without applying any pressure, between two parallel-faced plates. Wherever a gap exists under this condition, the strip is “unflat”. There are two kinds of “unflatness” – thickness non-uniformity (such as frown, profile, etc.) and geometric non-uniformity called shape defects such as (wavy strip, bent strip, coil set, center buckle, etc.).
Flatting (Kinking)
The sudden yielding, with simultaneous appearance of stretcher strain markings, taking place in hot-rolled or annealed sheet or strips when deformed.
Flat Rolled Steel
Steel produced on rolling mills utilizing relatively smooth, cylindrical rolls. The width to thickness ratio of flat rolled products is usually fairly large. Examples of flat rolled steel are hot-rolled, cold-rolled, and coated sheets and coils, tin mill products, etc.
Flexibility
The quality or state of a material that alloys it to be flexed or bent repeatedly without undergoing fracture.
Float and Sink Test
The cleaning qualities of a particular coal are determined by this test, also commonly known as a washability test. This test effects a fractionation of coal by size and specific gravity. The test consists in crushing coal to proper size and floating individual sizes of it on liquids having densities of 1.30. 1.40. 1.50. 1.60 etc., to determine the weight and character of the material that floats and sinks n each liquid. The proportion of coal, and the ash and sulphur content of the different fractions, provides reasonably complete data on the washability characteristic of a tested coal. Extreme fines may be evaluated by froth flotation.
Flocculation
A coating defect consisting of the formation of clusters of particles separable by relatively weak mechanical forces, or by a change in the physical forces at the interface between the liquid and the dispersed particles.
Flourspar
Naturally occurring calcium flouride (CaF2) used as a flux in basic steel making.
Flow Lines
Texture showing the direction of metal flow during hot or cold working. Flow lines often can be revealed by etching the surface or a section of a metal part.
Flow Marks
A coating defect consisting of the poor flow out of the coating on the substrate causing a ribbed (ribbing) or ridged appearance.
Flush Slag
The slag which is deliberately taken-out or comes out due to controlled boil from any steel making furnace.
Fluting
- Visible line markings that sometimes appear on the surface of flat rolled products during forming; associated with non-uniform yielding of the metal; occurs when the steel is formed into cylindrical or arc shaped parts. 2. The kinking, or breaking of a sheet generally caused by curing the sheet on two small a diameter. Fluting, or paneling as it is often called, can be avoided by working the steel before bending. Steel with a definite yield point (a visible break in the stress-strain curve) will generally tend to flute.
Flux
An iron cleaning agent. Materials such as limestone, lime, flourspar etc. 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.
Footage of Coil
The length of the steel strip that makes up a coil.
Forge
The section of the works used to produce wrought iron blooms, slabs or bars for subsequent reheating and re-rolling.
Forgeability
Ability to undergo plastic deformation by forging.
Forging
An article produced by hot working the metal under a hammer or press. It may also refer to the process followed in producing the article.
Forge Pigs
Pig iron suitable for conversion to wrought iron in the puddling furnace.
Formability
The ease with which a metal can be shaped through plastic deformation. The evaluation of the formability of a metal involves measurement of strength and ductility, as well as the amount of deformation required to cause fracture. Workability is used interchangeably with formability; however, formability refers to the shaping of sheet metal, while workability refers to shaping materials by bulk deformation (i.e. forging or rolling).
Forming
Rough shaping the stock into use preparatory to the final forging operation.
Fraze
A rough edge along the flash line after clipping.
Fractional Distillation Process (of Air)
The air is first compressed to an elevated pressure, followed by progressively cooling it to saturation temperature in steps in a series of highly efficient heat exchangers. Condensation and freezing out of moisture, carbon dioxide and hydrocarbons take place as the temperature is lowered, after which hydrocarbons still remaining are removed in adsorbent traps. The cold, purified air is finally separated into its constituents in fractionating (distillation) columns. The requirements for heat removal by refrigeration at the low temperature level are met by expansion of a portion of the cold compressed air in an expansion turbine.
Free Carbon
The part of the total carbon content in steel or cast iron present in elemental form as graphite.
Front End
The inside lap of the produced coil, or the outside lap of the consumed coil.
Fuel Injection
Hydrocarbon fuels are injected into the blast furnace through the tuyeres to control the flame temperature, increase the reducing power of the bosh gas and at the same time, replace some of the coke. In the presence of large quantities of coke, the hydrocarbon fuels can burn only to carbon monoxide and hydrogen; consequently, they produce less heat than the coke they replace so that they control the flame temperature, but the reducing gas they produce is more effective than that produced by combustion of coke. Many different fuels have been used – natural gas, coke oven gas, oil, tar and pulverized coke, even slurries of coal in oil.
Fuller
That part of the die used to reduce a portion of the stock to the appropriate form of the forging
Full Annealing
This consists of heating the steel to a temperature above the transformation range, holding for one or two hours, and then cooling at a predetermined rate to obtain the desired microstructure. This process is used when it is desired to refine the grain structure and produce a lamellar pearlite.
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 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.
Full Hard
Cold rolled coils coming from the Strip Steel that have not been annealed.
Full Strip
Strip in which the edges are shorter than the middle, thus causing distortion of the cross section.