Abstract: Aiming at the problem of high occurrence of surface crack defects in 301 stainless steel billet, a thermomechanical coupled model for the formation and stress and deformation of solidified shell in 301 stainless steel slab continuous casting mold was established. The model considered characteristic of high temperature phase change and solidification in mold of peritectic steel. The 3D transient heat conduction finite element, the element birth and death technology and the 3D thermoelasticplastic contact finite element method were used to solve the problem by ANSYS software. The solidification process of the 301 stainless steel slab mold was studied. The results indicate that the temperature is lowest on the center of width face of mold exit, the temperature is highest from the corner of 40 mm distance, the shell thickness is thinnest, and the shell temperature increases with the increasing of δ-ferrite transformation content at the exit, the shell thickness get thin. The displacement of slab wide face center is small, but largest in the corner; narrow surface displacement is greater than the width of face. With the increasing of δ-Fe transformation content, the level of stress decrease at the exit, the cracking index increase near the hot spot and occurrence of crack probability increases.

Key words: 301 stainless, mold, ferrite content, thermal-mechanical coupling