Tailoring the deformation behaviour of a medium Mn steel through isothermal intercritical annealing

A novel concept of varying the strain hardening rate of a medium Mn steel with 8 wt.% Mn by varying the duration of the intercritical anneal after hot rolling was explored. It was found that the stability of the austenite phase showed an inverse square root relationship with intercritical annealing duration and that the maximum strain hardening rate showed a linear relationship with austenite stability. The change in austenite stability was attributed to continuous Mn enrichment with increasing intercritical annealing duration. Twinned martensite was also found to be the most likely product of the martensitic transformation during deformation.