A-TIG WELDING AS A SOLUTION FOR NICKEL AND MANGANESE SAVINGS IN DUPLEX STAINLESS STEEL WELDED JOINTS
The paper presents the influence of the activation flux and shielding gas on tungsten inert gas welding of the duplex stainless steel. In introduction part the productivity and the cost-effectiveness of A-TIG welding for duplex stainless steels was explained. In the experimental part X2CrNiMoN22-5-3 7 mm thick stainless steel has been welded in butt joint. The welding process was performed by a robot with TIG equipment. With selected A-TIG welding technology preparation of plates and consumption of filler material (containing Cr, Ni and Mn) have been avoided. Specimens from the produced welds have been subjected to tensile strength test, macrostructure analysis and corrosion resistance analysis. The results have confirmed that this type of stainless steel can be welded without edge preparation and addition of filler material containing critical raw materials as Cr, Ni and Mn when the following welding parameters are set: current 200 A, welding speed 9,1 cm/min, heat input 1,2 kJ/mm and specific activation flux is used.