Laser-tig hybrid welding of very thin austenitic stainless steel sheets

Laser welding of austenitic stainless steel sheets to produce thin wall pipes requires an excellent cut edge preparation and a very precise fitting. In order to relax these requirements, laser-TIG hybrid welding of very thin 316L stainless steel sheets (0.4-0.8 mm thick) in a butt joint configuration has been studied. A diode-pumped Nd:YAG laser has been combined with a TIG torch, with the laser trailing. The observation of this hybrid welding has shown that the TIG arc is stabilized by the laser process, even at the high welding speeds used in this study (15 m/min), impinging on the melting pool produced by the laser beam. This laser-TIG hybrid welding could produce good quality seam welds with a worse cut edge preparation than laser welding.