Electron Back-Scatter Diffraction Studies of the Microstructure of a Cold Rolled Interstitial Free Steel Guided by Synchrotron X-Ray DiffractionWednesday (26.09.2018) 12:03 - 12:06 S1/01 - A04 Part of:
Hot and cold rolling are used for large-scale industrial processes, and can produce a rather complex intermixing of grain refinement, dislocation arrays and stacking faults, distorting the crystallographic lattice and interfering with the motion of other defects. Modern Electron Back Scatter Diffraction (EBSD) studies allow a direct, albeit local, determination of defects accumulation. Geometrically Necessary Dislocation arrays and fragmentation due to deformation processes can be separated by components by post-processing the misorientations obtained by EBSD.
X-Ray Diffraction (XRD) allows a global characterization of the microstructure, through the analysis of the height and shape of the diffraction peaks. Moreover, synchrotron XRD enables such analysis in relation with the sample orientation. In this work we use XRD to determine the texture of an Interstitial Free Steel, cold rolled to 70 % reduction, and relate the measured texture with the defect storage on different texture components through diffraction peak broadening analysis. With that purpose we create Generalized Pole Figures (GPF) of Full Width Half Maximum (FWHM), and we use the pole figure to ODF inversion method in the FWHM GPFs to find a generalized Orientation Distribution Function (ODF) which can be compared with the regular ODF used in texture analysis. We use these results to guide the analysis of EBSD measurements of the same samples to obtain a more direct estimation of the anisotropy of the defect storage on the samples. We found that the gamma fiber, usually present in rolled BCC materials is the component which tend to store more defects, although X-Ray diffraction methods fail to distinguish which kind of defects are the ones being stored. The typical alpha fiber was also found but it was rather cleaner from defects. Both results are in agreement with previous literature results for similar materials.