MATHEMATICAL-MODEL ANALYSIS ON THE GROWTH OF INITIALLY SOLIDIFIED SHELL

Irregular growth of initially solidified shell in continuous casting i s analyzed quantitatively, taking account of the shell deflection. Tem perature, thermal stress, and shell deformation are calculated simulta neously in cross section of the initially solidifying shell. Shell irr egularity obtained from this calculation is in agreement with the expe rimental results. This means the model can simulate the phenomena in t he mould. Heat resistance at the interface between mould and metal is dominant only for a few seconds from meniscus. After that, heat resist ance in the initially solidified shell becomes dominant. This means th e careful control of initial solidification for a few seconds from men iscus is important to decrease the irregular shell growth. Calculated results shows that more even thermal resistance between mould and meta l, higher speed casting and milder cooling rate will be preferable in decreasing the irregularity.