Kinetics of deformation-induced martensitic transformation under cyclic loading conditions

Abstract

Deformation-induced martensitic transformation (DIMT) has been investigated for many years mainly under monotonic loading conditions. However, the evolution of the DIMT under non-monotonic loading conditions has rarely been studied. The present work experimentally explored the development of DIMT under tension-compression as well as torsion cyclic loading conditions and showed fluctuating behavior within loading cycles in austenitic stainless steels measured by Feritscope, which was not observed under monotonic loadings. The present study showed that the fluctuation of the martensite measurement was related to the dual-phase features and could be explained by the Villari effect in the martensite phase. The martensite contents are assumed to increase monotonically with the effective plastic strain and are distributed along with principal stresses. A unified kinetics model for DIMT was proposed for both monotonic and cyclic loading conditions and verified experimentally. The anisotropic development of DIMT can be described by the model in combining with cyclic plasticity.