Mechanism of misorientation development within coalesced martensite

Abstract

Coarse crystals of martensite can form by the coalescence of thin individual platelets of martensite under appropriate circumstances. Although these coarse grains are essentially single crystals, there exist significant orientation gradients across their dimensions. It is demonstrated that these gradients arise because of the plasticity induced in austenite due to the transformation strain associated with martensite growth. The resulting localised change in austenite orientation is then inherited by the new martensite growth, which consumes the deformed austenite.