Mesoscopic Response Behavior Modeling and Simulation of Heat Resistant Stainless Steel X8CrNi25-21

Considering the characteristic of heat resistant stainless steel X8CrNi25-21, the classical constitutive model Johnson-Cook (JC) was modified based on plasticity-elasticity mechanics and dislocation dynamics. A constitutive model was established based on the dislocation theory, which could reflect the size effect and mesoscopic response behavior. Based on dislocation pile-up model, some experiments were conducted, including quasi-static tension and SHPB tests, to analyze microscopic parameters such as crystal size and crystal orientation. The objects used in the experiments were of mesoscale nonstandard parts, making corresponding heat treatment process to change sample grain size. The material experiment results show the performance change regularity of microscopic plastic distortion and parting action, and provide parameters for the mesoscopic constitutive model of heat resistant stainless steel X8CrNi25-21.