Molecular Dynamics Simulation of 40Cr/Q345 Hot Compression Process

In this study, the hot compression process of 40Cr/Q345 seamless bimetallic ring was investigated by molecular dynamics simulation. The effects of temperature and strain rate on stress-strain, dislocation, grains, atomic diffusion behavior and nucleation were investigated during the hot compression process. It was found that increasing the temperature and decreasing strain rate could reduce the stress during hot compression. Grain size was also affected by the effects of temperature and strain rate. High temperature and excessive fast strain rate were not conducive to grain refinement. The change of atomic positions during the compression process drove the nucleation and growth, forming the stacking fault structure of the HCP with the slatted FCC. In addition, higher temperatures could promote the formation of diffusion layers, while an increase in strain rate was not conducive to the diffusion of atoms. Atomic structure at the interface was analyzed by radial distribution function and bond energy; the results showed that the inter-diffused atoms at the interface have a strong bond strength. A diffusion layer with high strength could be obtained.