Microstructure and mechanical analysis of SS321 in CO2 laser beam welding joint

The paper presents the results of the laser beam welding of SS321, measurements of distortion, residual stress, weld bead shape, and metallurgy of weld joints. The laser CO2 laser beam welding uses an L4 orthogonal array. Weld distortion and residual stresses were assessed along the transverse axis using a vernier height gauge and X-ray diffraction technique, with the optimal desired value for a lower-the-better-quality feature zero. All combinations resulted in sound welds (porosity-free), and the joint microstructure, SEM/EDX, and mechanical analysis were carried out. All measured residual stresses are compressive, which is a desirable result. The stresses are within the yield limits and self-balances with the structure, and factor of safety of all the joints is 1.58. The results obtained from the tensile tests indicated that the welded specimens exhibited higher strength and ductile.