The effect of reversed austenite on mechanical properties of 13Cr4NiMo steel: a CPFEM study

Abstract

In order to investigate the effect of reversed austenite on the mechanical properties of 13Cr4NiMo steel, a meso scale crystal plasticity finite element model (CPFEM) was established to simulate the deformation induced martensitic transformation (DIMT) and micromechanical behavior during tensile deformation. The results demonstrate that the mechanical stability of the film-like austenite embedded in the martensite lath boundary is greater than blocky austenite within the martensite lath. The film-like austenite will preferentially undergo DIMT during initial plastic deformation prior to blocky austenite. After deformation, the tempered martensite yields and deforms plastically, while adjacent new martensite is elastically deformed. The incompatible deformation leads to the introduction of dislocations in the tempered martensite and increases the work hardening rate. The new martensite, that is transformed from film-like austenite, significantly increases the true strain of the adjacent martensite matrix, which is beneficial to the plasticity and toughness, but has little contribution to the increase of matrix stress. New martensite, transformed from blocky austenite, increases the von Mises stress of the adjacent martensite matrix, which improves the tensile strength and strain hardening capacity, but makes little contribution to the increase of matrix strain.