Phase transitions and transformation-induced plasticity of steel in the framework of continuum mechanics

Abstract
Distortion of steel under cooling is inevitably connected with phase changes (PTs) and transformationinduced plasticity (TRIP). We formulate a model describing these coupled phenomena, in which motion, temperature and phase fractions are considered as a "thermo-kinetical process with phase changes". The essential feature of the model is an appropriately generalised concept of stress-free intermediate configuration generated by TRIP. By means of the Clausius-Duhem inequality we restrict the set of admissible material laws. It is shown that the known laws for phase transitions as well as of TRIP are admissible in this model. We do not consider classical plasticity, although the present model can be adapted to allow for plastic deformations. By simplification and linearization we get a model discribing a quenching test. Numerical results are obtained via a finite-element method.