Comparison of X-ray residual stress measurements for rolled steels

Residual stress occurs in almost every processing such as casting, rolling, molding, welding, and mechanical processing. A high residual stress level can significantly increase the risk of unexpected product failure from various boundary conditions. In particular, cyclic-dependent fatigue damage is much affected by the residual stress of components. Hence, accurately monitoring the residual stress will be very useful to maintain safety and to predict the repair period and the remaining life of products. X-ray diffraction is a common nondestructive technique that can be used to determine the levels of residual stress in near-surface layers of a component. Therefore, in this study, residual stress distribution in plate-type specimens of rolled steel sheets was measured by the X-ray stress measurement method. The degrees of elastic and plastic deformations were estimated by using Cr-Kα and Mo-Kα1 characteristic X-rays on SPHD and SPCD steels.