The ductility behavior of a high-Mn twinning induced plasticity steel during cold-to-hot deformation

The ductility behavior of a high-Mn TWIP steel (containing 30% wt Mn) has been studied using tensile testing method in a wide range of temperature (100-1000 °C) under the strain rate of 10−4 s−1. The hot compression characteristics of the experimental alloy are considered to assist in explaining the related deformation mechanisms. The results indicate that the ductility decreases with temperature; however, two regions of moderately improved ductility have also been realized. The former is attributed to the reduction of twinning activity by increasing the temperature. On the other hand, the activation of dynamic recovery at 400 °C causes the ductility to increase. The fracture surface observations denote the occurrence of grain boundary sliding at temperatures above 500 °C. As the dominant restoration process alters to partial dynamic recrystallization at 800 °C, the tensile ductility continues to decrease. By increasing the temperature to 1000 °C, the fraction of dynamically recrystallized grains is significantly increased and the ductility is improved.