Simulation of the massive austenite-ferrite transformation under uniaxial loading

The massive austenite-ferrite phase transformation has been simulated on an atomic scale by means of a multi-lattice kinetic Monte Carlo method. The simulated system involved a ferrite-austenite bicrystal under various uniaxial loads and for a variable number of vacancies at the interface. The results show that the massive transformation from austenite to ferrite is controlled by the local rearrangement of austenite atoms initially blocking unoccupied ferrite lattices sites. The growth mode is strongly dependent on the orientation of the interface. The effects of loading and vacancy concentration at the interface are discussed in terms of their impact on the necessary local rearrangement of austenite atoms. It is shown that local, relaxed clusters of atoms surrounding a vacancy play an important role for the kinetics of the transformation.