Investigation of the mechanical behaviour of multi-phase TRIP steels using finite element methods

Abstract

In recent years, the development of high-strength steels such as multi-phase TRIP (transformation-induced plasticity)-aided steels have shown great promise due to their excellent combination of high strength and ductility, which allows for the use of thinner car frame components and subsequently weight reduction. The TRIP effect, characterized by the phenomenon known as strain-induced martensitic transformation (SIMT), enhances the work hardenability of such steels as the austenite phase transforms to the much harder martensite phase during plastic straining. However, various factors exist which affect the mechanical behaviour of TRIP steels. This study will aim, through the use of finite element models, to investigate the role and influence of each of these factors on the TRIP effect in multi-phase TRIP steels. These factors include the rate at which the martensitic transformation proceeds, the state of stress to which the material is subjected to and the interaction between the surrounding matrix and embedded retained austenite islands in multi-phase TRIP steels. Investigation of these factors will provide further insight on each of their contributions to the TRIP effect in order to exploit the potential benefits offered by these steels.