Microstructure and residual stress distribution of dissimilar joints of SS321 to Hastelloy C-276 using CO2 Laser Beam Welding: An experimental validation

This study applies a 3D model built for butt dissimilar joints welded using a laser beam. The thermo-mechanical study of SS321 and Hastelloy C-276 uses a volumetric Gaussian heat source model. Ansys parametric design language code is executed in ANSYSTM software for the simulation. Using the CO2 laser beam welding procedure, the simulation’s parameters serve as the experimental input procedures. We employ x-ray diffraction methods to quantify residual stresses in the weldments and evaluate the joint quality. The thermal results show that the fusion zone experiences maximum temperature, and the conduction occurs on the SS321 side. The residual stresses are tension at the fusion zone for simulation and experimentation. The welds exhibited full penetration and a consistent “Y” shape across all samples, indicating good structural integrity without internal defects. The factor of safety from the Finite Element Analysis (FEA) is 1.73, and the experimentation is 2.20. The residual stress varies by 21% from measured and FEA. Studies were carried out to characterize the weldments for their mechanical and metallurgical properties. Tensile tests confirmed that the weld zone’s strength is higher than the parent metals.