Continuous casting of steels

This chapter reviews the technology of continuous casting of steel. In the case of steel, the volume change from liquid to solid is approximately 3.5%. This is the main driving force for the motion of residual liquid, which exists in interdendritic regions and is enriched with solute elements and with harmful impurities. The three major problems of cracks, segregation and inclusions have essentially been solved under normal conditions of steady-state casting. Sometimes, longitudinal surface cracks on the cast slab are observed in the initial part of the casting. In this region, the mould surface is quite cold and the condition of the mould flux is different from that under steady state conditions. Steel grades which are sensitive to crack formation should be cast later in the casting sequence. The technology should be developed so as not to decrease the casting velocity, even in periods of ladle exchange of different steel grade.