A slab is a semi-finished block of steel with a rectangular cross-section much wider than it is thick, cast on a continuous caster and later reheated and rolled into hot rolled coil or plate. Slabs are the starting point of the whole flat steel chain, and are traded internationally between steelmakers that cast more than they roll and rolling mills that have no melt shop.
Also called
Steel slab
CC slab
Continuously cast slab
Semi-finished steel
Thin slab
Plate slab
Brammen
AR
البلاطات الفولاذية (سلابات)
ZH
板坯
DE
Brammen
FR
Brames
ES
Planchones (desbastes planos)
IT
Bramme
TR
Slab
RU
Сляб
Main formsContinuously cast slabs (conventional and thin), occasionally rolled slabs from ingots
Typical sizesConventional 150–300 mm thick, 800–2,600 mm wide, 5–12 m long, up to about 40 t; thin slab 50–90 mm
Main standardsChemistry and grade agreed to the final product standard (EN 10025, EN 10111, ASTM A36, API 5L…); mill specifications
Key gradesLow-carbon and ultra-low-carbon for forming, structural (S235–S355, A36), HSLA, API line pipe, pressure vessel, ship plate
Typical usesFeed for hot strip mills (HRC) and plate mills; traded semi-finished steel
Overview
Almost all slabs today are made by continuous casting: liquid steel from the converter or electric furnace, refined in the ladle, flows through a tundish into a water-cooled copper mould, and the solidifying strand is drawn out, straightened and cut to length with torches. A conventional slab caster makes slabs 200–300 mm thick; a thin-slab caster makes 50–90 mm slabs that go straight into a linked rolling mill without cooling.
Because the slab is an intermediate product, its specification is the chemistry and cleanliness needed for the final product — a slab for API X70 line pipe coil or for offshore plate is a very different thing from a slab for commercial-quality sheet, even if they look the same. Internal quality (centre segregation, porosity, inclusions) and surface quality (cracks, oscillation marks) matter because defects are rolled into the final product; slabs may be scarfed or ground before rolling.
Slabs move in international trade from producers with surplus casting capacity — Brazil, Russia and the CIS, Iran, India, Indonesia and others — to re-rollers in Asia, the Americas, Europe and the Middle East that own hot strip or plate mills but no steelmaking. Prices are usually quoted FOB or CFR per tonne and follow HRC and billet prices.
Steelmaking in the Gulf is mostly geared to long products, casting billets for rebar and wire rod. Hadeed (SABIC) in Saudi Arabia casts slabs from DRI-based electric arc furnace steel for its own hot strip mill, and several further flat-steel projects based on DRI and electric furnaces have been announced in the region. Rolling mills elsewhere in the Middle East also buy imported slabs.
Forms & sizes
Conventional slabs
200–300 mm thick, typically 1,000–2,200 mm wide (up to about 2,600 mm for plate mills), cut to 5–12 m
Thin slabs
50–90 mm thick, rolled directly in compact strip plants; rarely traded
Ingot or rolled slabs
Made from ingots for very heavy plates and special grades
Condition
As cast, scarfed or ground; hot charged or cold; marked with heat and slab number
Standards & grades
There is no separate product standard for slabs in general trade: the order states the chemistry, the grade of the final product and the casting and inspection requirements.
Steel Mills - Agents & Traders · Stockist - Distributor · Base Materials · Dubai
