準安定オーステナイト多結晶粒材におけるラスマルテンサイト組織形成のPhase-field・転位-結晶塑性解析

抄録

Although strength of TRIP steels can be compatible with ductility owing to deformation-induced martensitic transformation, there is currently no model describing simultaneously the deformation and microstructure formation processes of TRIP steel. In this report, we introduce the basis vectors of martensitic transformation derived in the previous report into the crystal plasticity model and develop a new material model based on a dislocation-based crystal plasticity model coupled with a multi-phase-field one. Also, we consider plastic deformation of austenite phase for more realistic analyze. After that, we use this model to reproduce the formation process of martensitic lath-block structure in a metastable austenitic polycrystal. As a result, it is shown that the microstructure of lath martensite is numerically formed in a polycrystalline micro-specimen using 6 variants in a CP group.