Phase transformations in low-carbon steels, modelling the kinetics in terms of the interface mobility

The mechanical properties of steel are determined by the microstructure tha t develops during the production process and is a joint result of effects o f chemical composition and of heat treatment. This paper deals with the kin etics of the phase transformation between the high temperature FCC-phase au stenite and the low temperature BCC-phase ferrite as it occurs during contr olled cooling. In order to predict the transformation kinetics, a physical model has been developed that considers both composition effects and the ac tual lattice transformation rate. The model is verified against experimenta l dilatometry data for three lean carbon-manganese steel grades. Notwithsta nding the model having no adjustable parameters, it yields adequate simulat ions of the transformation kinetics.