Influence of the measurement parameters on depth-resolved residual stress measurements of deep rolled construction steel using energy dispersive x-ray diffraction

In this study, the influence of different measurement parameters of energy dispersive residual stress measurements on the obtained residual stress depth profiles of deep rolled construction steel S355 G10+M was investigated. Especially the diffraction angle TH and afterwards the measuring time t per inclination angle PS were varied. A diffraction angle of TH = 20° shows an acceptable compromise between achievable information depth and detected total intensity of diffracted X-ray quanta. Furthermore, a measuring time per inclination angle PS of t = 2,400 s leads to an acceptable standard deviation regarding the determined residual stress states. With these parameters for the energy-dispersive measurement, a comparison between angle-dispersive and energy-dispersive determination of residual stress depth profiles was carried out. Quantitative similarities between these two methods were observed, whereby the energy-dispersive determined residual stress depth profiles are rather discontinuous. A possible explanation could be found in the model used for the calculation of the net-plane-dependent radiographic elastic constants (XEC). In general, the energy-dispersive residual stress measurement was qualified for the determination of residual stress depth profiles of deep rolled construction steel. Based on the findings, a time-efficient non-destructive residual stress measurement can be carried out in the future with the discussed measurement parameters at maximum possible information depth.