Microstructure and property of rotary double-focus laser-TIG hybrid welding of 304# stainless steel

In order to improve the property of stainless steel welding,a rotary double-focus laser-tungsten inert gas (TIG) hybrid welding technique was proposed,in which the rotary double-laser beam and the TIG arc were applied in welding at the same time.The rotary double-focus laser-TIG hybrid welding torch was designed,and a detailed experiment of rotary double-focus laser-TIG hybrid welding on the 304# stainless steel plate with different welding parameters was carried out.The results showed that the hybrid function between the double-focus laser and arc was the main factors affecting the microstructure of welded joint,and that the rotation frequency affected the mierostructure and micro-hardness of welded joint,the lower the rotary frequency,the higher the hardness because of smaller microstructure induced by re-melting of the welding line.The results are applicable in theoretical analysis and experimental research of laser-TIG hybrid welding technique.