Stability of retained austenite in TRIP-assisted steels

A theory is developed for the quantitative representation of the strain induced transformation of retained austenite in low alloy, TRIP-assisted steels of the type developed for the automobile industry. It is possible, therefore, to calculate the fraction of austenite as a function of the plastic strain, chemical composition, deformation temperature and the starting amount of austenite. The effect of composition and temperature is expressed through the free energy available for transformation. Good agreement has been obtained with published experimental data. The model can be used to investigate the stability of the austenite during plastic deformation.