Dynamic mechanical properties of the Fe–30Mn–3Si–4Al TWIP steel after different heat treatments

The dynamic mechanical properties of Fe–30Mn–3Si–4Al TWIP steel were studied using a split-Hopkinson pressure bar at room temperature with strain rates between 700 and 5000 s−1. It was found that the effect of heat treatments on the dynamic mechanical properties is limited. With increasing the strain rate from 700 to 2500 s−1, the strain hardening dominates the process. When the strain rate is further increased to 5000 s−1, the effect of strain softening is active. The density of deformation twins increases with the strain rate, and then decreases a little with further increasing the strain rate. The deformation behavior is attributed to the opposite effects of pulse duration and impact pressure.