Simulation Study on Vacuum Gas Quenching of Cold Working Dies

抄録

During heat quenching process, temperature transition, microstructure evolution and stress/strain interaction occur simultaneously at different scales. Establishment of a multi-field coupling model need deal with microstructure evolution, thermophysical parameters, and boundary conditions. The specific heat capacity and thermal conductivity of Cr12MoV were obtained using the synchronous thermal analyzer and laser thermal conductivity analyzer. The heat transfer coefficient model of nitrogen was obtained through inverse algorithm. Vacuum Gas Quenching and isothermal quenching were simulated by establishing suitable FEM models. The evolution process of temperature, microstructure, and stress/strain during the quenching process were analyzed. Microstructure evolution during quenching process is predicted successfully. Bainite/martensite multi-phase was formed during isothermal quenching process. The temperature gradient between the surface and center of the cold working die was reduced. The microstructure of samples was compared with FEM simulation results. The comparisons show that the simulation results are consistent with experimental results.