Kinetics of secondary phase precipitation during spinodal decomposition in duplex stainless steels: A kinetic Monte Carlo model - Comparison with atom probe tomography experiments

This paper presents the first simulations of the kinetics of spinodal decomposition and G-phase precipitation occurring in ferrite of duplex stainless steels. The kinetics was simulated using a simple but effective atomic kinetic Monte Carlo model in a ternary alloy. The simulations reproduced the α/α′ spinodal structure with precipitates at the α/α′ interface. The comparison of simulated results with experiments shows that the simulations quantitatively reproduce the kinetics of phase transformation and the synergy observed experimentally between the spinodal decomposition and G-phase precipitation. By following the vacancy pathway, we show that the coarsening of G-phase precipitates proceeds via diffusion along the α/α′ interfaces. The simulations made it possible to explain the origin of the kinetic synergy between spinodal decomposition and G-phase precipitation.