Investigation on un-peened and laser shock peened weldment of Inconel 600 fabricated by ATIG welding process

The present investigation articulates the joining of Inconel 600 plates using activated tungsten inert gas (ATIG) welding process. Before joining of Inconel 600 plates, welding parameters have been optimized and suitable flux has been selected to produce complete weld penetration in a single pass welding. The various mechanical and metallurgical characterizations were performed on the un-peened ATIG (UP-ATIG) weldment. The experimental results attested that the tensile failure occurred in the weld zone and also the tensile strength is lower than the base metal (BM) because of coarser grain structures and tensile residual stresses in the weld zone. Laser shock peening (LSP) was carried out on the welded joint to enhance its properties. After LSP treatment, the significant improvement was observed in the laser peened ATIG (LP-ATIG) weldment and the fracture occurred at the parent metal side owing to the compressive residual stresses developed by LSP. Residual stress measurements indicated that the compressive residual stresses were higher at the surface and they decrease with increasing depth.