A phase-field study of the physical concepts of martensitic transformations in steels

A 3D elastoplastic phase-field model is employed to study various driving forces associated with martensitic transformations, plastic deformation behavior as well as the habit plane concept. Usage of thermodynamic parameters corresponding to Fe–0.3%C alloy in conjunction with anisotropic physical parameters of steels as the simulation parameters have yielded the results in reasonable agreement with experimental observations. From the simulation results, it is concluded that there exist three critical driving forces that control the transformation and also that the plastic deformation behavior of the material greatly affects the transformation. The model predicts the initial habit plane of the first infinitesimal unit of martensite as (−1 1 1). The model also predicts that, as the transformation progresses, the above mentioned martensite domain rotates and finally orients along the new habit plane of (−2 1 1).

► Critical driving forces associated with martensitic transformation are estimated.
► Plastic relaxation rate affects the transformation and microstructure evolution.
► Low relaxation rate promotes multi-domained martensitic microstructure.
► High relaxation rate promotes growth of a single martensite domain.
► The model predicts the final habit plane of martensite to be (−2 1 1)γ.