Modeling of Precipitation Behavior of Complex Precipitates in Ferrite and Validation with Experiment

Abstract

Based on solid solution theory, mass conservation law and classical nucleation, growth and coarsening theory, a thermo/kinetic model is developed to predict the precipitation behavior of complex precipitates in Nb‐V bearing steel. The equilibrium composition of matrix and precipitates is calculated by the thermodynamic model and is input in the kinetic model to calculate the driving force for precipitation at a given temperature. The diffusivity and concentration of alloying elements is considered in the entire precipitation process. The effect of interfacial energy of precipitates and activation energy on precipitation behavior are studied. Simulation results indicate that the interfacial energy plays a significant role in the entire process of precipitation and there is no overlap between nucleation and coarsening when the interfacial energy is in the range of 0.5–0.55 Jm−2. The mean particle diameter predicted by the proposed model is compared with the experimental results and a good agreement was obtained.