| Abstract Scope |
To date, while most studies on medium Mn steel have applied intercritical annealing starting from low-temperature to stabilize the reverted austenite, interphase precipitation (IP) has not been implemented in medium Mn steel, as IP formation takes place during austenite-to-ferrite transformation.
This study demonstrates the feasibility of forming IP and preserving retained austenite simultaneously in a microalloyed 3Mn steel proccessed by dynamic austenite-to-ferrite transformation in a dilatometer. The sample was first fully austenitized and then cooled to the transformation temperature, at which deformation was applied. During deformation, dynamic austenite-to-ferrite transformation occurred, allowing IP to form. Meanwhile, the carbon content in the untransformed austenite became supersaturated beyond the local equilibrium condition due to the refined prior austenite grain size achieved through the alloy design. Therefore, after final cooling, a medium Mn steel with retained austenite and interphase precipitation was successfully realized, opening a new processing window for medium Mn steel. |