Spatial Internal Material Load and Residual Stress Distribution Evolution in Synchrotron In Situ Investigations of Deep Rolling

Abstract

Mechanical loading scenarios, comparable to a deep rolling process, were reproduced in static indentation experiments on AISI 4140H steel samples with a cylindrical deep rolling tool and investigated in situ with synchrotron radiation at the European Synchrotron Radiation Facility (ESRF) on beamline ID11. Through the use of spatially resolved diffraction data, two-dimensional (2D) equivalent von Mises stress maps were recorded during loading and after unloading. The material modifications were analyzed in the material below the contact zone for different loading conditions. It was demonstrated that the characteristics of internal material load and residual stress distributions can be evaluated through data fitting and the effect of the applied force could be linked to the stress fields by an empirical model. The experimental values were then compared to a contact mechanics approach in order to analyze the correlation between the theoretical maximum loading stresses and the stored elastic residual stresses remaining by considering the dissipation of a certain amount of energy through plastic deformation.