Multiscale computational simulation of deformation behavior of TRIP steel with growth of martensitic particles in unit cell by asymptotic homogenization method

Due to the strain-induced martensitic transformation (SIMT), the strength, ductility and toughness of TRIP (transformation-induced plasticity) steel are enhanced. Such favorable mechanical properties of TRIP steel can be realized by the appropriate combination of the SIMT behavior and deformation behavior of both austenite and martensite. However, since the SIMT and deformation behavior of both phases depend strongly on the conditions of the working environment such as temperature, strain rate and stress system, the desired mechanical properties are obtained only in a fairly restricted working environment. On the other hand, martensitic particles of various sizes, shapes and orientations can be observed and are distributed spatially in the microstructure of TRIP steel, therefore it is possible that the mechanical properties of TRIP steel strongly manifest a dependence on the geometrical inhomogeneity and configuration of martensite. If the geometrical configuration and inhomogeneity of martensite can be controlled, we can expect to enhance the mechanical properties of TRIP steel. Here, in order to investigate the effects of the geometrical configuration and inhomogeneity of martensite in the austenitic matrix on the macroscopic deformation behavior of TRIP steel, the computational simulation of the deformation behavior of TRIP steels with the growth of an ellipsoidal martensitic particle embedded in the center of the austenitic unit cell, is performed using the homogenization technique.