A crystallographic model of fcc/bcc martensitic nucleation and growth

A crystallographic model of face-centered cubic/body-centered cubic martensitic nucleation and growth has been developed in which the glissile martensitic interface is described in terms of discrete transformation and misfit dislocations within the framework of the Frank–Bilby equation. In the present model heterogeneous nucleation of a martensitic embryo occurs spontaneously by dissociation of an existing perfect dislocation under certain conditions, such as the catalysis on grain boundaries. Autocatalytic dislocation is proposed to be responsible for embryo growth, then nucleation and subsequent growth of a single embryo can be regarded as an autocatalytic process. As a natural result the crystallographic features of grown martensite are consistent with the phenomenological theory of martensite crystallography. Martensitic nucleation in this model agrees with many experimental observations.