A Model for Deformation Behavior of Metastable Austenitic Steel

摘要

At temperatures above the M{sub}s temperature, austenite-to-martensite transformation can occur when the summation of a mechanical energy due to the externally applied stress and the chemical driving force exceeds a critical value. The transformation is known to be induced via stress-assisted nucleation on the same nucleation sites responsible for the athermal martensitic transformation during cooling. In the temperature range above M{sub}f{sup}σ and below M{sub}d, when the externally applied stress becomes over the yield limit of parent austenite, the transformation is dominated by strain-induced nucleation on new nucleation sites created by the plastic strain. It is well established that the strain-induced nucleation occurs predominantly at shear-band intersections. The transformation via the stress-assisted and strain-induced nucleation is hereafter denoted as mechanically-induced martensitic transformation.