Optimum process conditions based on stresses distribution and crack formation for twin roll strip casting

Abstract
To keep steady casting production for strip casting, not only control of cooling and solidification but also stresses and crack formation should be taken into consideration. In order to compute the thermal mechanical stresses and susceptibility of the material to crack during strip casting process, a coupled finite element simulation on temperature, solidification and inelastic deformation was carried out based on a unified viscous fluid model including elastic, visco-plastic deformation, thermal expansion and dilatation due to solidification. The distribution of temperature and stresses on strip surface and in nip zone was analyzed under various casting speeds. Crack formation possibility index of casting strip at different positions and process conditions was obtained by a principal stress crack model. The weakest positions and dangerous direction subjected to crack are predicted. Effect of casting speeds on stress distribution and crack formation was clarified and the optimum casting process was discussed on this basis.