Laser Welding of AISI 316 Steel: Microstructural and Stress Analysis

Thermal-stress field in the welded region was modeled incorporating the finite element model. Temperature and stress fields were predicted at different cooling periods. The morphological and metallurgical changes in the welded region were examined using optical and scanning electron microscopes, energy dispersive spectroscopy and X-ray diffraction. The residual stress formed at the surface vicinity of the weld was determined using the X-ray diffraction technique. It was found that the residual stress predicted agreed well with the experimental data. The solidification cracking did not occur in the weld section during the cooling period. The microhardness in the weld cross-section was almost 1.4 times the base material hardness.