CO/sub 2/ laser welding of AISI 321 stainless steel

CO/sub 2/ laser welding of AISI 321austenitic stainless steel has been carried out. Bead on plate welds on 2 mm thick steel were performed with 450W CO/sub 2/ laser at speeds ranging from 200 to 900 mm/min. It was observed that weld depth and width was decreased with increasing the speed at constant laser power. Butt welds on different sheet thickness of 1, 2 and 2.5 mm were performed with laser power of 450 W and at speed 750, 275 and 175 mm/min, respectively. The microstructures of the welded joints and the heat affected zones (HAZ) were examined by optical microscopy and SEM. The austenite/delta ferrite microstructure was reported in the welded zone. The microhardness and tensile strength of the welded joints were measured and found almost similar to base metal due to austenitic nature of steel. (author)