Residual Stress Depth Profile in Surface Layers of Shot-Peened Decarburised Steels

Surface decarburization of construction steels occurs during their forging, drawing and casting. As a softening process, decarburization leads to a considerable fatigue limit decrease. This detrimental effect can be reduced by strengthening the decarburised layer using plastic deformation induced by shot peening. As a result compressive residual stresses are created in the surface layer. The aim of the contribution is to present the results of X-ray diffraction analysis of residual stress depth profiles in surface layers of sand-blasted and shot-blasted steels. Depth distributions of macroscopic (first-order) residual stresses were determined up to approx. 500 mu m beneath the blasted surface.