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Definitions of phrases and terms used in steelmaking

A guide to the language of steel

The steelmaking process is complex, with many phrases and terms that are unique to the industry.

Alloy steels

Alloy steels have enhanced properties due to the larger proportion of elements such as manganese and silicon present in carbon steels.

Annealing

The heat treatment process by which steel products are reheated to a suitable temperature in order to remove stresses from previous processing and to soften them and/or improve their machinability and cold forming properties.

Apparent consumption

The sum of net industry shipments within a given country or region, plus its imports and minus its exports.

Bar

A finished steel product, commonly in flat, square, round or hexagonal shapes. Rolled from billets, bars are produced in two major types: merchant and special.

Billet

A semi-finished steel product with a square cross section up to 155mm x 155mm. This product is either rolled or continuously cast and is then transformed by rolling to obtain finished products like wire rod, merchant bars and other sections. The range of semi-finished products above 155 mm x 155 mm are called blooms.

Blank

Steel sheet of high dimensional precision, in simple or complex form, sometimes multi-thickness, constituting principally automobile body parts.

Blast furnace

A furnace used in integrated steelmaking in which coke and iron ore react together under a hot air flow to form liquid hot metal, also called pig iron.

Bloom

See billet

Carbon steel

A type of steel that generally has only a small quantity of elements other than carbon, silicon, manganese, sulphur and phosphorus, so it has no significant alloying element.

Coal

The primary fuel used by integrated iron and steel producers.

Coated steels

Steel is coated by a heat process, or through electrolysis, with a layer to protect the metal base against corrosion. The most commonly used coating material is zinc which can be applied either using the heat process (hot-dip galvanising) or using electrolysis (electro-galvanising). An organic coating (paint, plastic) can also be deposited on the zinc layer.

Coil

A finished steel product such as sheet or strip which has been wound or coiled after rolling.

Coke

A form of carbonised coal burned in blast furnaces to reduce iron ore pellets or other iron-bearing materials iron.

Coke ovens

Ovens where coke is produced. Coal is usually dropped into the ovens through openings in the roof, and heated by gas burning in flues in the walls within the coke oven battery. After heating for about 18 hours, the end doors are removed and a ram pushes the coke into a quenching car for cooling before delivery to the blast furnace.

Cold rolling

Passing a sheet or strip that has previously been hot rolled and picked through cold rolls (below the softening temperature of the metal). Cold rolling makes a product that is thinner, smoother and stronger than can be made by hot rolling alone.

Continuous casting

A process for solidifying steel in the form of a continuous strand rather than individual ingots. Molten steel is poured into open-bottomed, water-cooled moulds. As the molten steel passes through the mould, the outer shell solidifies.

CRC

Cold rolled coil (see cold rolling)

Crude steel

Steel in the first solid state after melting, suitable for further processing or for sale. Synonymous with raw steel.

Direct reduction

A group of processes for making iron from ore without exceeding the melting temperature. No blast furnace is needed.

Electric arc furnace

A furnace for scrap-based steelmaking. Once the furnace is charged and covered, graphite electrodes are lowered through holes in the roof. The electric arc travelling between the electrodes and the metallic charge creates intense heat which melts the scrap. Alloying elements can be added during the process.

Electrical steels

Specially manufactured cold rolled sheet and strip containing silicon, processed to develop definite magnetic characteristics for use by the electrical industry.

Flat products

A type that is produced by rolls with smooth surfaces and ranges of dimension, varying in thickness. The two major flat steel product categories are thin, flat products (between 1mm and 10mm in thickness) and plates (between 10mm and 200mm thick and used for large welded pipes, ship building, construction, major works and boilers).

Galvanised steel

Produced when hot or cold rolled sheet or strip is coated with zinc, either by the hot-dipping or electrolytic deposition processes. Zinc coating applied by the hot dip method is normally heavy enough to resist corrosion without additional protective coating. Materials electronically galvanised are not used for corrosion-resistant applications without subsequent chemical treatment and painting, except in mild corrosive conditions, due to the thin coating of zinc. Galvanise is a pure zinc coating. A special heat-treating process converts the pure zinc coating to a zinc/iron alloy coating, and the product is known as Galvanneal.

HDG

Hot dip galvanised (see galvanised steel)

Hot and cold rolling mill

Hot-rolling mill: Equipment on which solidified steel preheated to a high temperature is continuously rolled between two rotating cylinders.
Cold rolling mill: Equipment that reduces the thickness of flat steel products by rolling the metal between alloy steel cylinders at room temperature.

Hot metal

Molten iron produced in the blast furnace.

HRC

Hot rolled coil (see hot rolling)

Integrated steelmaker

A producer that converts iron ore into semi-finished or finished steel products. Traditionally, this process required coke ovens, blast furnaces, steelmaking furnaces and rolling mills. A growing number of integrated mills use the direct reduction process to produce sponge iron without coke ovens and blast furnaces.

Iron ore

The primary raw material in the manufacture of steel.

Ladle metallurgy

The process whereby conditions (temperature, pressure and chemistry) are controlled within the ladle of the steelmaking furnace to improve productivity in preceding and subsequent steps, as well as the quality of the final product.

Limestone

Used by the steel industry to remove impurities from the iron made in blast furnaces. Limestone containing magnesium, called dolomite, is also sometimes used in the purifying process.

Line pipe

Used for transportation of gas, oil or water generally in a pipeline or utility distribution system.

Long products

Long products are used in all industrial sectors, particularly in the construction and engineering industries. The group makes heavy long products, light long products and wire-drawn products.

Lost time injury frequency rate (LTIFR)

LITFR is the number of injuries which has resulted in an employee or contractor being away from work at least one day after the day it occurred, per million hours worked.

Mechanical tubing

Welded or seamless tubing produced in a large number of shapes to closer tolerances than other pipe.

Minimill

A small non-integrated or semi-integrated steel plant, generally based on electric arc furnace steelmaking. Minimills produce rods, bars, small structural shapes and flat rolled products.

Net ton

See ton

Oil country tubular goods (OCTG)

Pipe used in wells in oil and gas industries, consisting of casing, tubing and drill pipe. Casing is the structural retainer for the walls; tubing is used within casing oil wells to convey oil to ground level; drill pipe is used to transmit power to a rotary drilling tool below ground level.

Open-hearth process

A process for making steel from molten iron and scrap. The open-hearth process has been replaced by the basic oxygen process in most modern facilities.

Pellets

An enriched form of iron ore shaped into small balls.

Pig Iron

The product that results from smelting iron ore with a high-carbon fuel such as coke

Plate

A flat rolled product from slabs or ingots of greater thickness than sheet or strip.

Real consumption

For any country or region, apparent consumption for such country or region adjusted for inventory changes or stockists and end users.

Refining stand

A stage in the process of making crude steel, during which the crude steel is further refined (i.e. most residual impurities are removed) and additions of other metals may be made before it is cast.

Rolling mill

Equipment that reduces and transforms the shape of semi-finished or intermediate steel products by passing the material through a gap between rolls that is smaller than the entering materials.

Semi-finished products

Steel products such as billet, blooms and slabs. These products can be made by direct continuous casting of hot steel or by pouring the liquid steel into ingots, which are then hot rolled into semi-finished products.

Sheet

A flat rolled product over 12 inches in width and of less thickness than plate.

Sheet piling

Rolled sections with interlocking joints (continuous throughout the entire length of the piece) on each edge to permit being driven edge-to-edge to form continuous walls for retaining earth or water.

Sinter plant

A plant in which iron ore is crushed, homogenised and mixed with limestone and coke breeze and then cooked ("sintered") to form sinter which is the main ferrous component of blast furnace burden.

Sintering

A process which combines ores too fine for efficient blast furnace use with flux stone. The mixture is heated to form clumps, which allow better draft in the blast furnace.

Slab

A semi-finished steel product obtained by rolling ingots on a rolling mill or processed through a continuous caster and cut into various lengths. The slab has a rectangular cross section and is used as a starting material in the production process of flat products, i.e. hot rolled coils or plates.

Slag

A by-product, containing inert materials from the ‘burden’ (the materials put into the blast furnace at the beginning of the steel making process), that is produced during the melting process.

Sponge iron

The product of the direct reduction process. Also known as direct reduced iron (DRI).

Stainless steels

Stainless steels are distinguished from carbon steel by their chromium (ferritic steel) content and, in certain cases, nickel (austenitic steel). Adding chromium to carbon steel makes it more rust and stain-resistant, and when nickel is added to chromium stainless steel it enhances its mechanical properties, for example its density, heat capacity and strength.

Standard pipe

Used for low-pressure conveyance of air, steam, gas, water, oil or other fluids and for mechanical applications. Used primarily in machinery, buildings, sprinkler systems, irrigation systems, and water wells rather than in pipelines or distribution systems.

Strip

Flat steel coil products, with widths of less than 600mm for hot rolled products and less than 500mm for cold rolled products. The wider flat products are called wide strips.

Structural pipe and tubing

Welded or seamless pipe and tubing generally used for structural or load-bearing purposes above-ground by the construction industry, as well as for structural members in ships, trucks, and farm equipment.

Structural shapes

Rolled flange sections, sections welded from plates, and special sections with at least one dimension of their cross-section three inches or greater. Included are angles, beams, channels, tees and zeds.

Thin strip continuous casting

Casting technology that takes liquid steel and casts it into solid strip in one step, thereby eliminating the need for a continuous slab caster and hot strip mill.

Tin coated steel

Cold rolled sheet, strip or plate coated with tin or chromium.

Ton (t)

  1. A unit of weight in the US Customary System equal to 2,240 pounds. Also known as long ton.
  2. A unit of weight in the US Customary System equal to 2,000 pounds. Also known as short ton. Also known as net ton.

Tonne (T)

A metric tonne, equivalent to 1,000 kilograms or 2,204.6 pounds or 1.1023 short ton.

Wire rods

Coiled bars of up to 18.5 millimetres in diameter, used mainly in the production of wire.

Wire: drawn and/or rolled

The broad range of products produced by cold reducing hot-rolled steel through a die, series of dies, or through rolls to improve surface finish, dimensional accuracy and physical properties.

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