A comparison of the pitting corrosion behavior of 304 stainless steel by tig, laser and laser-tig hybrid welding

In this work, the 304 stainless steel was welded by laser welding, Tungsten Inert Gas (TIG) welding and Laser-TIG hybrid welding respectively. A series of comparative experiments were carried out to examine the relationship between welding methods and the pitting resistance of joints. The phases present in the resolidified zone of the welded specimens were analyzed by X-ray diffraction. The pitting corrosion behavior of the stainless steels in the welded and unwelded was studied by means of electrochemical measurements. X-ray diffraction analysis shows that the phases present in the weld metal depends on the heat input and the welding methods. The specimens of hybrid welding and laser welding exhibit better pitting resistance than TIG arc welding. Under the condition of full penetration, the Laser-TIG hybrid welding method is the most feasible in welding stainless owing to high welding speed and excellent pitting resistance.