Residual stress measurements of welded components using synchrotron and neutron diffraction

Over the last decade, there has been a growing interest in a better understanding of welding residual stresses in engineering components. Residual stresses have a significant effect on corrosion, fracture resistance, creep and corrosion/fatigue performance and a full understanding of these stresses is desirable. In this research high energy synchrotron (70 keV) radiation (at the Advanced Photon Source) and thermal neutrons (at the Lucas Heights Research Reactor) have been employed to investigate and compare the residual stress characteristics in fully restrained samples before and after post-weld heat treatment. This paper explores the use of state-of-the-art instruments such as neutron and synchrotron diffraction for evaluation of residual stress in carbon steel welded components. The changes in residual stress distribution in the weldment before and after post-weld heat treatment are reported together with traditional mechanical tests. The measurements of residual stress around the weld achieved in this work significantly improves the resolution at which residual stress in welded components has been measured.