Influence of annealing temperature on mechanical properties and microstructures of a high manganese austenitic steel

By using scanning electron microscope (SEM) equipped with electron back-scattered diffraction (EBSD), transmission electron microscope (TEM) and room temperature tensile deformation test, the mechanical properties and microstructure evolution of a high manganese austenitic twinning-induced plasticity (TWIP) steel 25Mn-3Cr-3Al-0.3C-0.01N were investigated for the cold-rolled sheets annealed at different temperatures. The results show that annealing temperature has a tremendous effect on grain size and mechanical properties of the cold rolled high manganese austenitic TWIP steel. The features of the annealed grain microstructures of this steel can be characterized by coincidence site lattice (CSL) Σ3 at grain boundary. The occurrence frequency of Σ3 grain boundary and deformation twins in this steel has a close relation to annealing temperature. The microstructure evolution at different strain levels was finally described for the annealed and tensile deformed high manganese austenitic steel.