Residual stress evolution in cold-rolled steels

An experimental analysis is presented to assess the residual stress evolution in cold-rolled steels. The study aims to establish the influence of a yield strength gradient on the increase of residual stress in a hardened material when it is subject to a bending fatigue load. Rectangular specimens, obtained from cold-rolled plates and having different hardening levels, are analysed and the residual stress evolution, due to three-point bending load application, is evaluated with respect to the initial value. The comparison between tests on different specimens shows that the yield strength gradient plays an important role in the residual stress field evolution.