Modeling of phase transformation behaviors by cementite formation at isothermal bainite transformation region in TRIP-assisted steels

Abstract

It is a major factor that the retained austenite fraction to determine mechanical properties of cold rolled TRIP-assisted steels. To obtain the maximum retained austenite, cementite is retarded by addition of Si, Al at isothermal bainite transformation heat treatment (IBT). In this study, carbide free bainitic-ferrite and cementite transformation behaviors are simulated by classical nucleation and growth model, and it is predicted that complex transformation behavior as the formation of cementite during carbide free bainitic-ferrite transformation at IBT. The effect on bainite transformation behavior as Si, Al contents is investigated by dilatometric and XRD experiments, results which are compared with the modeling are analyzed.