The plasticity increasing effect induced by high strain rate is related to the startup of twinning deformation and the fracture mechanism changed from intergranular fracture at low strain rate to intragranular dimple at high strain rate.

• 中高锰钢高应变速率增塑效应,主要与孪生变形大量启动有关,其断裂机制由低应变速率的沿晶断裂转化为高应变速率的晶内韧窝韧性断裂。