A multi-scale simulation for studying grain growth in ferritic steels

Abstract

A multi-scale simulation for studying grain growth, which has a form of the meso-scale simulation based on the realistic grain boundary/surface energy data obtained from the atomistic simulations, has been introduced. A systematic scheme to identify and distinguish individual grain boundaries from one another according to the misorientation and inclination in polycrystalline materials has been developed. Based on this scheme, a grain boundary energy database for bcc Fe is constructed as a suitable form for implementation on mesoscale grain growth simulations. A 3-D phase-field model for grain growth combined with a grain boundary energy database has been proposed. The phase-field model is applied to a grain growth simulation of polycrystalline bcc Fe to investigate the effect of anisotropic grain boundary energy on the microstructural evolution and its kinetics. This multi-scale simulation has been applied to investigation of texture evolution in electrical steel fields as a practical application. A change of surface energy anisotropy caused by phosphorus surface segregation depending on crystallographic planes is calculated by atomistic simulations, and this information is applied to the meso-scale simulation for grain growth. Then, texture evolution is investigated for bcc Fe sheets.