Austenite stability and heterogeneous deformation in fine-grained transformation-induced plasticity-assisted steel

We report the mechanistic explanation of the variation in Lüders strain in fine-grained transformation-induced plasticity-assisted steel. The austenite stability is demonstrated to have a profound influence on the Lüders strain. Furthermore, it is shown unambiguously using a thermodynamic analysis that the transformation of austenite is strain-induced. The work results in a generic method of distinguishing the cause of martensitic transformation during tensile tests, given that both stresses and strains are necessarily present beyond the yield point.