XRD peak broadening characterization of deformed microstructures and heterogeneous behavior of carbon steel

The XRD peak broadening is in direct relation with the structural anisotropy and heterogeneity in the rolling plane during deformation by deep drawing in mild soft steel. The inhomogeneous structures give internal stresses at different scales, which strongly influence the superficial mechanical properties. The XRD method is a local, quantitative and selective technique, which made particularly possible to evaluate intensity and distribution of microscopic internal stresses in deformed microstructures. In that study different deformed samples (<2%, 3%, 6%, 9%, 12%, 15%) were analyzed by DRX peak broadening. The evolution of peak broadening for deformation’s ratio is compared to evolution of the yield strength R0.2% obtained by macroscopic mechanical tests with variable angle to the rolling direction, for a simulation of drawing behavior. It may be noted that the peak broadening has good linear relationship with the yield strength. As well the anisotropy of macroscopic behavior has been observed through XRD peak broadening. The relationship between structure heterogeneity and microscopic internal stresses seems well established.