CAFE simulation of directional solidification structure of low nickel austenitic stainless steel

In this paper, through the secondary development of ProCAST&CAFE software, the dynamic boundary conditions of solidification process were established, the temperature field and solid fraction in the directional solidification process of low nickel austenitic stainless steel were simulated, and the effect of the pull rate on solidification microstructure was discussed. The results shows that the withdrawal rate is in the range of 15~200 μm/s, as the solidification speed increases, the isotherm becomes dense, gummy zone narrowing. And as the solidification rate increases, the primary dendrite arm gradually refines and the secondary dendrite arm becomes dense and coarse. In addition, as the withdrawal rate increases in the range of 15 to 200 μm/s, the lateral heat dissipation of the edge of the casting is gradually smaller than that of the central longitudinal heat dissipation, and the axial deviation of the dendrites is reduced from 27.66 ° to 25.964 °. At the same time, the comparative analysis simulation results are in good agreement with the experimental results, and the simulation calculation process is more reasonable.