Effect of heat treatments on the residual stresses in a welded joint

The welds are the site of high residual stresses, localized in the vicinity of the weld cracks. Their presence caused many type of damage mode as stress corrosion, fatigue, sudden failure and increasing the temperature of ductile/brittle transition. Residual stresses in restrained welds and weld repairs are very complex. The heat treatment affects the value and distribution of residual stress in the specimen. This peak stress in all three samples occurred not at the toe, but in the middle of the weld bead, where the yield stress is higher. The use of the neutron diffraction (ND) technique for residual stress measurements is described. In addition, studies of macrostructure and hardness were conducted. The results of different tests conclude the influence of heat treatment on Residual stresses in welds.