Strain Rate Dependent Mechanical Properties of TWIP Steel

Abstract

The effect of strain rate on the work-hardening behavior of high-manganese twinning-induced plasticity (TWIP) steel has been investigated. The influence of adiabatic heating and deformation rate on the mechanical properties was studied by quasi-static and dynamic tensile tests with synchronous temperature and strain measurements. TWIP steel has excellent strain-hardening behavior under both quasi-static and dynamic loading conditions. Strain rate has negligible effects on yield and tensile strength, but the uniform and total elongation decreases under dynamic tests. TWIP steel has excellent energy absorption (EA) capacity of above 55 kJ/kg at all strain rates compared to dual-phase steels, transformation-induced plasticity steel and ferritic steels. However, the EA of TWIP steel is slightly lower compared to austenitic stainless steels. A rise in temperature due to adiabatic heating has led to the increase of stacking fault energy, thereby resulting in a change of twinning behavior or the promotion of dislocation glide under dynamic loading.