LAUSR

Abstract It is widely accepted that the lattice transformation strain and plastic shearing of a martensite embryo preset its final lattice orientation. However, the phenomenological theory of martensite crystallography (PTMC) solves an inverse problem where accommodative slip or twinning systems leading to certain structures are sought among a lot of admitted candidates. This approach explaining the known result still cannot unambiguously predict the latter or, moreover, its dependence on the transformation conditions. In order to avoid uncertainty of PTMC, a micromechanical model is formulated that directly follows a natural sequence of the transformation strain and plastic accommodation. With slip systems uniquely selected in this way at habit planes {111}γ and {557}γ, corresponding orientation relationships are predicted and then verified by relevant data on low carbon lath martensite.