Mechanical behavior prediction of TWIP steel in plastic deformation

This study aims to predict the influence of twinning volume fraction and grain size on the mechanical behavior of TWIP steel in plastic deformation with a dislocation-based model considering austenite twinning. The preceding model was implemented into FEM codes based on the conventional elastoplasticity increment theory, and verified by the experimental data of Allain et al. (2002). Then the influence of twinning volume fraction and grain size on the work-hardening of TWIP steel in tensile deformation was investigated. A damage factor was proposed to evaluate the failure trend in plastic deformation based on the Freudenthal fracture criterion, and the effect of twinning volume fraction and grain size on the proposed factor was analyzed. The results indicate that higher twinning volume fraction improves strength and ductility, delays the failure of TWIP steel. However, finer grain improves strength and ductility, but may deteriorate fracture resistance of TWIP steel.