Predicting macromechanical behavior of dual phase steels based on actual micromechanical modeling

In this paper the macromechanical behavior of dual phase steel based on actual microstructure has been predicted. In order to prepare dual phase steelsc (DP) of different percent phase combinations، a low carbon steel (C-Mn) was subjected to intercritical annealing treatment (ICT) and quenched in water. Then، the actual microstructures of dual phase steels were obtained by metallographic analysis and optical microscopy. A 2D representative volume element (RVE) was generated by finite element code Ansys on the basis of actual microstructure which was obtained by image processing code in Matlab software. The individual single-phase flow curves were obtained based on the dislocation theory and the local chemical composition of constituent. The results of 2D micromechanical RVE models under periodic boundary conditions and tension loading were compared with the experimental results. It is shown that the 2D micromechanical model can predict both strength and ductility for low volume fraction of martensite in dual phase steels. The 2D micromechanical modeling may then be used to portray the local strain evolution of the individual phases in the DP microstructures.