The Novel Combination of Strength and Ductility in 0.4C‐7Mn‐3.2Al Medium Manganese Steel by Intercritical Annealing

By altering the temperature and duration of intercritical annealing (IA), the mechanical stability of retained austenites (RAs) is intentionally regulated in newly designed cold-rolled medium manganese steel of Fe-0.4C-7Mn-3.2Al (in wt%). Consequently, a novel combination of ultimate tensile strength (UTS) and total elongation (TE) (e.g., 1118 MPa and 67%) is obtained in duplex steel, and the corresponding product of UTS and TE can reach 75 GPa%. Both twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP) take effect step by step during deformation and are conducive to the outstanding properties.