MATHEMATICAL MODEL OF THE STEEL DEFORMATION AT MARTENSITIC TRANSFORMATION
The task of the deformation description at phase transformation is a part of a problem involving creation of two-level model of steel inelastic deformation at thermomechanical treatment based on approaches of the physical plasticity theory. The gradient of transformational deformation of representative mesovolume is constructed on the basis of the crystallographic theory of martensitic transformation and describes deformation with the invariant plane. It is expressed through a vector of a normal to the invariant plane and a shear vector which set transformational system (by analogy with system of crystallographic shear for dislocation sliding). According to the Kurdyumov - Sachs’s orientation relationships, there are 24 transformational systems, expressions for which component are given in the article. Features associated with application of a measure of inelastic deformation of mesolevel (crystallite) representative volume at martensitic transformation are considered. In particular conditions of activation of these systems at different types of loading are defined.