Simulation of the kinetics of precipitation reactions in ferritic steels

Abstract

Computer simulations of diffusion-controlled phase transformations in model alloys of Fe–Cr–C, Fe–Cr–W–C, Fe–Cr–Si–C, and Fe–Cr–Co–V–C are presented. The compositions considered are typical for ferritic steels. The simulations are performed using the software DICTRA and the thermodynamic calculations of phase equilibria are performed using Thermo-Calc. The thermodynamic driving forces and the kinetics of diffusion-controlled precipitation reactions of M 23C 6, M 7C 3, cementite and Laves-phase (Fe, Cr) 2W are discussed. The simultaneous growth of stable and metastable phases is treated in a multi-cell approach. The results show remarkable effects on the growth kinetics due to the competition during simultaneous growth.