Electron Back-Scatter Diffraction Studies of the Microstructure of a Cold Rolled Interstitial Free Steel Guided by Synchrotron X-Ray Diffraction

M. AVALOS; R. BOLMARO; E. BENATTI; H. BROKMEIER; N. DE VINCENTIS; N. SHELL

Darmstadt

Congreso; Materials Science and Engineering Congress 2018; 2018

FEMS - TMS

Hot and cold rolling are used for large-scale industrial processes,and can produce a rather complex intermixing of grain refinement, dislocationarrays and stacking faults, distorting the crystallographic lattice andinterfering with the motion of other defects. Modern Electron Back ScatterDiffraction (EBSD) studies allow a direct, albeit local, determination ofdefects accumulation. Geometrically Necessary Dislocation arrays andfragmentation due to deformation processes can be separated by components bypost-processing the misorientations obtained by EBSD.X-Ray Diffraction (XRD) allows a global characterization of themicrostructure, through the analysis of the height and shape of the diffractionpeaks. Moreover, synchrotron XRD enables such analysis in relation with thesample orientation. In this work we use XRD to determine the texture of anInterstitial Free Steel, cold rolled to 70 % reduction, and relate the measuredtexture with the defect storage on different texture components through diffractionpeak broadening analysis. With that purpose we create Generalized Pole Figures(GPF) of Full Width Half Maximum (FWHM), and we use the pole figure to ODFinversion method in the FWHM GPFs to find a generalized OrientationDistribution Function (ODF) which can be compared with the regular ODF used intexture analysis. We use these results to guide the analysis of EBSDmeasurements of the same samples to obtain a more direct estimation of the anisotropyof the defect storage on the samples. We found that the gamma fiber, usually presentin rolled BCC materials is the component which tend to store more defects,although X-Ray diffraction methods fail to distinguish which kind of defectsare the ones being stored. The typical alpha fiber was also found but it wasrather cleaner from defects. Both results are in agreement with previous literatureresults for similar materials.