Microstructure and Mechanical Properties Evolution of Fe-10Mn-2Al-0.4C-0.6V Cold-rolled Medium-manganese Steel during Intercritical Annealing

The microstructure and mechanical properties of Fe-10Mn-2Al-0.4C-0.6V cold-rolled medium-manganese steel were studied during annealing at 630 ℃. The results show that during the annealing process, martensite undergoes recovery decomposition and austenite reverse transformation, coarse austenite undergoes ferrite transformation, part of ferrite reverse transformation into austenite, and the equiaxed structure gradually increases. The austenite content reaches the maximum when annealed for 1 h, decreases gradually after the annealing time is prolonged, and the stability increases gradually. The tensile strength and yield strength decrease gradually with the increase of annealing time.