Constitutive modeling of TWIP/TRIP steels and numerical simulation of single impact during Surface Mechanical Attrition Treatment

In this work, a dislocation density-based model including the kinetics of twinning and martensitic transformations is developed to study the strain hardening behavior of twinning induced plasticity (TWIP) and transformation induced plasticity (TRIP) steels. Based on the proposed model, the volume fractions of twinning and martensitic transformations, the dislocation densities in austenitic and martensitic phases are calculated to analyze the effects of twinning and martensitic transformations on the mechanical behavior of TWIP/TRIP steels. Comparison between modeling results and experimental data shows that the proposed model can well predict the evolution of the volume fractions of twinning and martensitic transformations, as well as the macroscopic mechanical behavior. The model is implemented in a subroutine of ABAQUS Explicit to perform 3D simulations of a single impact to investigate the impact process during Surface Mechanical Attrition Treatment (SMAT).