Significance of control of austenite stability and three-stage work-hardening behavior of an ultrahigh strength high ductility combination transformation-induced plasticity steel

In the context of obtaining high strength-high ductility combination in transformation-induced plasticity steels, we underscore the practical significance of controlling the stability of austenite during deformation such that strain hardening induced by martensite transformation occurs at a critical strain. An optimized intercritical hardening at 750 C led to a ferrite austenite microstructure that was characterized by similar to 64% austenite and excellent combination of tensile strength of similar to 1000 MPa and elongation of similar to 65%, and a three-stage work hardening behavior. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.