“Ravenscraig pioneered continuous casting in British Steel flat products…” Dr. Jeremy Bray (Motherwell, South) House of Commons, 21 May 1990.
Slabs being cut to length at the twin-strand ConCast machine.
Continuous casting was an important advance in steelmaking. It did away with the need to cast and then reheat an ingot, saving time and energy.
Two single-strand continuous casting machines were installed at Ravenscraig in 1974 and a third, twin-strand machine in 1979.
The process involves a ladle of molten steel being carried to the casting plant by an overhead crane. The liquid is ‘stirred’ by the injection of inert gas and then placed onto a rotating turret. The steel is then poured into a reservoir called a tundish, a water cooled copper mould, which solidifies the outer shell of the liquid steel.
The steel continues to curve downwards through a series of rollers until it completely emerges at the other end of the machine in an entirely solid state.
The steel slabs are then cut to length by automatic gas-cutting equipment. When one ladle of steel is emptied into the machine another is moved into position to maintain a continuous flow via the tundish.
Twin-strand slab casting machine at Ravenscraig.
Ravenscraig’s ConCast plant largely replaced the slabbing mill, which was afterwards mainly used to supply the plate mill at the neighbouring Dalzell Steel Works.