Microstructure and property of nitrogen-alloyed high manganese austenitic steel under high strain rate tension

The microstructures and mechanical properties of 32Mn-7Cr-1Mo-0.3N steel under high strain rate tension companied with different deformation temperature are investigated by using of the split-Hopkinson pressure bar (SHPB). The results show that with increasing the strain rate and decreasing the deformation temperature the strength increase, but the elongation and the area reduction do not obviously decrease. The fracture surfaces of the tensile specimens all exhibit ductile characters with many dimples. The X-ray diffraction analysis (XRD) results show no ɛ′-martensite in all specimens. The transmission electron microscope (TEM) observations further confirm that the deformation microstructures are mainly composed of deformation twins and slipping bands or stacking faults.