Continuous steel casting - Metallurgical aspects

The useable properties of steels depend, first and foremost, on their chemical composition, which is adjusted in the liquid phase. Solidification then takes place in a form as close as possible to the desired end product: in slabs for flat products such as plates or sheets, in blooms or billets for long hot-rolled products.

Continuous casting (CC) is the steel solidification stage. The best performance of future products is achieved after hot deformation of the solidified semi-finished products to compensate for certain heterogeneities inherited from casting: geometry, surface appearance, internal health and mechanical properties in particular (figure 1 ).

The original basic idea behind continuous casting (figure 1 ) is to solidify a bar of infinite length in a bottomless ingot mould, extracting it as soon as its skin is sufficiently resistant, and continuing to cool it vigorously from the outside until it is completely solidified. In this way, a continuous supply of liquid is fed into a well, the walls of which become thicker and stiffer, enabling the bar to be extracted.