Interactions between Recrystallization and Austenite Reversion during Intercritical Annealing of a Cold‐Rolled Medium Mn Steel

Recrystallization and austenite reversion are two crucial physical metallurgical phenomena occurring during the intercritical annealing process of cold‐rolled medium Mn steel (MMnS), which can produce an ultrafine dual‐phase microstructure essential for achieving the superior strength‐ductility balance. To elucidate the microstructural behavior of concurrent recrystallization and austenite reversion, a tracing method based on the heterogeneous Mn distribution induced by softening annealing is employed to identify the distinct recrystallization modes in deformed ferrite and martensite. The potential interactions between recrystallization and austenite reversion are then assessed by monitoring Mn redistribution during intercritical annealing. Furthermore, the influences of recrystallization extent, controlled by different rolling reductions on austenite reversion, are also analyzed. These findings indicate that recrystallization significantly enhances both the nucleation and growth of reversed austenite in cold‐rolled MMnS. Grain boundaries (GBs) formed during recrystallization serve as rapid diffusion channels, thereby facilitating the efficient partition of Mn atoms to reversed austenite during intercritical annealing. The freshly nucleated finer austenite subsequently pins the GBs, inhibiting the coarsening of recrystallized ferrite. This process not only assists in preserving the refined dual‐phase microstructure, but also ensures a greater amount of austenite stabilized in the final microstructure at room temperature.