Effect of double annealing on microstructure and mechanical properties of Mn-TRIP steel

A novel double annealing process was applied to a Mn-TRIP steel. As result, great combination of yield strength 829MPa, tensile 1132MPa and total elongation 42.1% obtained. The improvement mechanical property contributed microstructure evolution. By process, ferrite grains were refined VC could effectively precipitate instead cementite, which the enhancement strength. Austenite fraction increased two types austenite morphology (block lath) In addition, Mn partitioning promoted, leading high enrichment in grains. Consequently, with stability provided continuous active TRIP effect, contributing work-hardening behavior increasing ductility.