LAUSR

Abstract The pulsating current approach in tungsten inert gas (TIG) welding is adapted for joining Hastelloy C-276. Microstructure examination revealed the absence of micro-segregation while employing UNS N06022 filler. Due to the prevalence of higher tensile stresses in the un-peened conditions, tensile failures were observed in the weld regions of both the joints irrespective of fillers. Low energy laser shock peening without coating (LSPwC) was carried out on the weld zones on both the sides of the joints with the pulse densities 2500 and 7500 pulses per cm2. This laser surface treatment had remarkably increased the tensile strength of the welded joints by shifting the location of tensile failures well away from the fusion zones for all the cases. Similarly, a considerable increase is observed in the notch toughness of both the joints in the LSPwC condition. The enhancement in tensile strength and notch impact toughness of the welds could be ascribed to the residual compressive stresses induced which were then confirmed by Sin2ψ method in X-ray diffraction (XRD) technique.