304 Stainless Steel Hot Deformation Conditions, Dynamic Recrystallization Behavior

304 austenitic stainless steel is one of the main materials of heavy forgings. However, the investigations of essential character in China far lag behind practical manufacture, furthermore, the further optimization of hot working process were firmly retarded.Single-stroke hot compression tests of type 304 austenitic stainless steel were performed on GLEEBL—1500D thermo-mechanical simulator to study the influence of deformation conditions such as initial grain size ,deformation temperature, deformation amount, quantity and strain rate to austenite recrystallization behaviors and flow-stress curves. The strain rate is 0.01,0.05,0.1,0.5s-1,and the deformation temperature is 950℃,1000℃,1050℃,1150℃, 1200℃.According to the tests, we have obtained the strain-stress curves, then calculated the deformation activation energies for dynamic recrystallization is 464kJ/mol.The critical strain of dynamic recrystallization and peak stress are also obtained along. Combined with metallurgy structures of sample after deformation, we found that lower strain rate and higher temperature are instrumental to dynamic recrystallization.Through quantitative analysis, models of recrystallized, such as kinetic and kinematics model, grain size model of 304 stainless steel are obtained by linear and nonlinear regression methods.Integrated those models into finite element analysis software-Deform, thermal stress simulation has coupled with 304 stainless steel dynamic recrystallization model simulation during the process of hot forming. This paper has simulated the process of hot compression forΦ50mm×75 mm specimens, the macroscopic thermal parameters and recrystallization with the fractions distribution was obtained. Comparing the values between the simulation and experiment, we found they are in good agreement which proved the accuracy of the dynamic recrystallization models and the possibility of applying the thermal-organization of coupled simulation technology into practice, so as to further optimize the technology.