Glossary of steelmaking terms

Alloy steel

steel with one or more specific elements added to create special properties

Annealing

the controlled heating and cooling to soften steel

Bar

steel shapes up to 75mm in diameter produced in straight lengths, such as rounds, squares, hexagons, angles, channels, flats, T -bar or reinforcing bar

Basic Oxygen Steelmaking (BOS) Vessel

a furnace where blasts of oxygen are used to transform iron into steel

Battery

a series of 10-100 tall, gas-fired, air-tight brick ovens in which coal is baked to form coke

Billet

a 12 metre long semi-finished steel shape, produced from caster or rolled from a bloom

Bloom

a steel shape, the product of continuous casting, varying in dimension. Usually about

630mm by 400mm and 5-6m in length

Carbon steels

Carbon steels represent the major percentage of steel production. As well as carbon, these steels may contain up to 1.65% manganese, 0.60% silicon and 0.60% copper

Casting

the process of pouring molten metal into a mould, so that the cooled solid metal retains the shape of the mould

Charging

feeding the furnace with raw materials

Coke

the end product after coal has been baked in coke ovens for about 18 hours

Cold strip mill

hot rolled steel strips are cold rolled to produce cold rolled steel strips, O.03rnm- 3.2mm in thickness

Continuous casting

continuous forming of semi- finished steel sections ego slabs, blooms, billet, direct from molten steel thus eliminating primary rolling operations

Continuous mill

mill with a number of stands of rolls arranged in tandem through which steel is rolled in one direction

Direct reduction

Direct reduction is a process which extracts iron from its ore without going through a molten stage. It produces solid iron which can be used as a scrap substitute

Drawing

pulling steel shapes through tapered dies to produce wire

Electric Arc Furnace (EAF)

a furnace that uses electric power to melt scrap steel to produce new steel

Fine ore

Fine ore iron ore which ha~a very small particle size and tends to be powdery in nature

Fluxing material

materials used in a furnace to assist in the refinement process. They generally lower the melting point of impurities in the molten steel, and combine with the impurities to form 'slag'.

Galvanise

the coating of iron or steel with zinc to protect it from rust

Heat

Heat one batch of steel from a steelmaking furnace

Hot Briquetted Iron (HBI)

a form of direct reduced iron, used mainly as feedstock in Electric Arc Furnace steel mills.

Hot metal

molten iron taken from the blast furnace for conversion to steel

Hot strip mill

a mill which rolls reheated slabs into strips, 1.2mrn-22mm in thickness

Ingot

an outdated method of shaping molten steel. Under this method solidified steel castings, ranging in size from a few tonnes up to about 30 tonnes, were made by teeming molten steel into a mould for forging or rolling into slabs, blooms or billets

Integrated

steelworks works including all major production stages from converting raw materials, such as coke and iron ore into iron and steel through to rolling mills

ladle

a 'bucket' lined with refractory bricks used to transport molten steel from process to process in a steel plant

Lump ore

a rich iron ore which, when crushed, has a size range between six and 35mm

Lance

a long metallic tube through which oxygen is blown into the 80S vessel under high pressure

Mini-mill

a small self-contained plant which melts scrap in an electric arc furnace, casts the molten steel, then reheats and rolls the steel into a variety of products

Open hearth furnace

steel refinement process largely superseded by Basic Oxygen Steelmaking

Pass

the opening between two grooved steel rolls which gives the shape to the steel being rolled

Pellets

fine particles of iron ore mixed with bonding clay and roasted into hard, round balls

for use as a blast furnace feed. Production is usually located near ore source

Pickling

Use of hot acid solution to remove oxides, scale and dirt from steel to ensure good surface quality in cold rolling

Pig iron

blast furnace iron cast into small ingots or 'pigs' weighing 20-30kg

Plate

wide flat rolled steel product at least 3mm thick, hot rolled from the slab

Plate mill

slabs are hot rolled to produce plates of maximum size up to 20cm in thickness and up to 4.45mm in width

Plating and Coating lines zinc

tin or special organic material is plated or coated on strips to produce corrosion resistant steel strips

Precipitators

equipment used to collect solid particles from a flow of gas or air

Primary mill

originally where steel ingots were rolled into semi-finished steel shapes ego slabs, blooms, billets, as a feed for product mills. Now used to describe any mill where steel is initially rolled

Product mill

mill which rolls semi-finished steel shapes into finished products to meet customer requirements, such as plates, bars, rods etc

PVC Steel

sheet steel coated with plastic used in white goods manufacture such as washing machines and refrigerators

Refractories

heat resistant materials used to line furnaces and ladles

Reheat furnace

gas-fired furnace used to heat steel shapes (billets, slabs etc) to the temperature required for rolling mill operations

Rods

round steel bars, ranging from 5.5mm to 18mm thick, produced in coils. Used as feed for wire mills

Rollforming

rolling coated steel into different profiles for roofing, fences, garage doors etc

Scarfing

use of oxygen flame jets to remove surface defects from semi-finished steel

Steel scrap

good quality steel such as the cropped ends of semi-finished steel products, steel that may have been damaged in production, and old steel goods such as car bodies, refrigerators etc

Section

hot rolled beam, channel, angle etc other than flat or strip steel

Semi-finished

products such as blooms, billets or slabs intended for further processing by rolling or forging

Sheets and strip

flat rolled steel product less than 3mm thick

Sinter

fine particles of iron ore, coke and limestone, roasted into lumps (agglomerated) for use as blast furnace feed. Production is usually at ironmaking plants.

Slabs

rectangular semi-finished steel shapes ranging up to about 250mrn x 2000mm

Slag

produced by the chemical combination of the flux and the impurities removed from the metal in ironmaking and steelmaking

Smelting

Smelting is a process used to separate iron from the impurities in iron ore

Stand

Stand an arrangement of rolls through which steel is passed to alter its shape. A mill may consist of one or more stands

Strand

bar and rod mill term referring to the number of steel bars which can be rolled through a mill simultaneously, side by side (eg a 4 strand rod mill)

Strip

flat steel product of a hot or cold strip mill (hot rolled between 1.2rnm and 25mm thick, cold rolled between 0.1mm and 8mm thick)

Sub-lance

Sub-lance device for molten steel temperature measurement and sampling

Tapping

running off molten steel from a furnace or vessel

Teeming

the pouring of molten steel from a ladle into an ingot mould or the tundish of a casting machine

Terne steel

sheet steel coated in a lead/tin alloy coating

Tinplate

sheet steel coated with a thin layer of tin, used for food cans, paint tins etc

Tundish

vessel that feeds molten steel into the top of a continuous caster

Tuyeres

copper nozzles arranged in a ring around the base of a blast furnace, through which the air blast is injected

Vacuum de-gassing

Vacuum de-gassing process which removes impurities from steel by extracting unwanted gases

Wire

wire is made by drawing (pulling) the cold rod through a series of tapered dies (steel blocks with holes) of diminishing size. This causes the wire to become longer and thinner. The dies are made from extremely hard material to withstand the wear and pull of wire