Continuous casting mould for square steel billet optimised by solidification shrinkage simulation

A transient, thermoelastic-viscoplastic finite element model has been applied using ANSYS to study the thermal and mechanical behaviour of the solidifying shell during continuous casting of steels. In the model, a gap dependent heat transfer condition was imposed in the boundary between shell and mould. Thermophysical properties (e. g. thermal linear expansion) depending on temperature and composition were derived from experiment data and empirical correlations. Continuous casting of square billets with different steel grades, B72LX and ER70S6, were simulated to investigate the evolution of shell temperature, stress and shrinkage with an indirect coupled approach. The results indicated that carbon content, pouring temperature and casting speed have obvious influence on shrinkage of billets. According to shrinkage compensating principle, the mould taper and inner cavity geometry were designed and optimised based on average shrinkage histories of the solidifying shell. The new design has performed well in industrial trials.