Continuous Casting of Steel Billets

In continuous casting, molten steel is poured without stop into a short, open-bottomed copper mould and drawn out below as a solid strand. The steel goes from the ladle to a tundish, which holds a reserve while ladles are changed and steadies the flow, and from there into the water-cooled mould. The mould oscillates so the steel does not stick, and a lubricating powder melts on the surface and traps slag. A thin skin freezes against the copper; the strand leaves the mould still liquid inside, is held by water-cooled rolls and sprayed with water until it is solid, then straightened and cut to length. Billet casters cast sections under 200 mm square, up to 12 m long, at up to 4 m a minute.