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Home> Learning Center> Iron & Steel Glossary
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
1. 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.
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