(S231)Deformation-induced martensitic transformation behavior of retained austenitedispersed in martensitic stainless steel

摘要

The deformation-induced martensitic transformation of retained austenite (γ) dispersed withinmartensite (α') or bainite matrix is effectively used for increasing elongation of high strength steels such as TRIPassisted steel, Q&P steel and tempered high Ni martensitic steel. To obtain the optimum mechanical property inthese steels, it is necessary to control the stability of retained γ and make it transform continuously duringdeformation to maintain the moderate work hardening to higher strain region. It is well known that the stability ofretained γ is dependent on its chemical composition and grain size; but the crystallographic character and therestraint effect by matrix should be also important. In this study, the deformation-induced martensitictransformation behavior of retained γ formed by partial reversion treatment of a martensitic stainless steel wasinvestigated by SEM/EBSD and TEM, and the dominant factor determining the behavior was discussed.