Study of Dislocation Substructures in High-Mn Steels by Electron Channeling Contrast Imaging

We have investigated the formation of dislocation substructures in high-Mn steels by electron channeling contrast imaging in the SEM. The coupling of electron channeling contrast imaging (ECCI) with electron backscatter diffraction (EBSD) provides an efficient and fast approach to characterize dislocation substructures under controlled diffraction conditions with enhanced contrast. The dislocation substructure of high-Mn steels at intermediate strain levels is characterized by cells and cell blocks with strong crystallographic orientation dependence. We observe a significant effect of strain path on dislocation patterning. Microband formation is enabled under shearing conditions. We explain this effect on terms of Schmid’s law.