Affiliations: Rutherford Appleton Laboratory, Didcot, Oxfordshire, United Kingdom | Department of Mechanical Engineering, Monash University, Caulfield East, VIC, Australia | School of Physics, University of Melbourne, VIC, Australia | Institute of Materials Engineering, ANSTO, Lucas Heights, NSW, Australia
Abstract: Welding residual stresses have important consequences for the performance of engineering components and high residual stresses can lead to loss of performance in corrosion, fatigue and fracture. Despite their importance, they are often the single largest unknown in industrial damage situations due to the difficulty of their measurement. In this paper, the neutron diffraction technique is used to investigate residual strains and stresses due to repair welding. The aim of this research was to characterize the residual stress distribution which arises in a welded component as a result of restraint and how it is reduced by subsequent post-weld heat treatment (PWHT). Three-dimensional residual strain/stress distributions are presented. The test results show that restraint during welding increases the levels of residual stress in all three directions. A significant stress relaxation due to PWHT has been observed. Results are also compared with values specified by the structural integrity assessment standard, BS7910.
Keywords: Residual stress, Neutron diffraction, Welding, Single bead-on-plate, Restraint
