5th International High Manganese Steel Conference - HMNS 2022

Abstract:
Samples from a medium manganese thermomechanical processed steel sheet show strongly preferred crystallographic orientations far from the random distribution. For the quantification of the retained austenite phase, a novel X-Ray diffraction (XRD) based method is presented that calculates the phase fraction from the measured texture data. By a geometrical averaging procedure in a large area of the reciprocal space, it is possible to define an orientation dependent phase fraction that can be related to the mechanical and magnetical properties along different directions. The structural information from XRD of the phases ferrite, retained austenite and epsilon martensite is used to setup a combined Electron Backscatter Diffraction (EBSD) and Energy Dispersive X-Ray detection (EDX) measurement on the scanning electron microscope (SEM). The distribution, shape and chemical composition of the phases is obtained with a high lateral resolution and is used to characterize the impact of deformation induced by an uniaxial reckling test on the microstructure. The filtered chemical composition of the individual phases is used to correct the atomic form factors and absorption calculations of the XRD postprocessing. The local misorientation of the EBSD data is evaluated with a kernel averaging method for each phase and correlated to the experimental data of the residual stresses measurement by XRD along different directions. The results of this orientation dependent analysis help to improve the understanding of the physical phenomena and mechanical strengthening mechanisms of medium manganese steels under deformation.