Nucleation site saturation and kinetic parameters of austenite-ferrite transformation in Fe - 9 % Cr alloys

The paper presents a theory of phase transformation kinetics in case of saturation of nucleation sites on grain boundaries as a variant of J.W. Cahn’s theory. Kinetic parameters that define nucleation and growth of ferrite particles along grain boundaries and into the volume of prior austenite grains are determined using available experimental data for Fe - 9 % Cr alloys with different carbon content. Calculated TTT diagrams of ferrite formation are in good agreement with experiment.