Cryogenic deformation microstructures of 32Mn–7Cr–1Mo–0.3N austenitic steels

The cryogenic deformation microstructures of impact and tensile specimens of 32Mn–7Cr–1Mo–0.3N austenitic steel were investigated using light microscopy and transmission electron microscopy. The results show that the deformation microstructures of the impact specimens are mainly composed of stacking faults, network dislocation, slip bands, and a few mechanical twins and ɛ-martensite. These microstructures cross with each other in a crystal angle. The deformation microstructures of the tensile specimens consist only of massive slip bands, in which a few mechanical twins and ɛ-martenite are located. Because of the larger plastic deformation the slip band traces become bent. All the deformation microstructures are formed on the {111} planes and along the <110> orientation.