LAUSR

Abstract The austenite (γ) reversed transformation of medium-Mn steel during intercritical annealing (IA) process was investigated based on different initial martensite (α') microstructure. The results reveal that the volume fraction of γ phase gradually increases from 29% to 38.2% with the decreasing degree of the α recrystallization. This is because the γ growth is controlled by Mn atoms diffusion from α to adjacent γ grains, and Mn atoms diffusion preferentially depends on the passageway of crystal defects such as dislocations. This method sheds light on intensifying initial crystal defects and inhibiting subsequent recrystallization to improve γ content of medium-Mn steels treated by cold-rolling and continuous annealing process.