The welding market is changing globally, becoming eco-friendly, robotized and automated. The tungsten inert gas welding (TIG) process is indispensable in industries that require high-quality welds with the absence of spatter and fumes. However, the production rate of TIG welding is very low, which limits its many applications. The present study introduces a novel TIG welding method called super-TIG welding. Super-TIG welding is able to produce a high production rate of welds compared to other fusion welding methods. In super-TIG welding, the novel C-type filler is used, which is different from the conventional TIG welding of circular wire. The relations of the heat input ratio in super-TIG welding to weld pool length and weld bead geometry were measured using the Inconel 625 C-filler. Two types of deposition techniques were used for a bead-on-plate welds, such as stringer beads and oscillation beads. The weld pool and bead geometry measurements are found to be different between stringer beads and oscillation bead techniques. The length of the molten pool and bead size were higher for oscillation beads over the stringer beads. These changes were associated with the difference in heat transfer contact area and bead height.

Super-TIG welding is a newly developed TIG welding process using C-type filler metal in TIG welding. In Super-TIG welding, C-filler can prevent the molten pool depression, which is caused by high pressure in the center of the arc during high current TIG welding. In this study, metal transfer modes for C-type filler metal were observed. During these observations, feeding heights were varied for the current of 430 A. It was observed that the stable and continuous bridging transfer along with the arc blow on filler at zero gap feeding height. An intermittent bridging transfer of bridging and separating was repeated at 2 and 4mm height. The arc and filler voltages were low at bridging and high at separating.

In carbon steel butt joint welding, uniform back bead formation and reduction of weld deformation are important. In most industrial sites, Ceramic backing is used for V-grooves for uniform back bead formation in FCAW and SAW. In this case, because the root pass has a large deposition area and a high heat input, a problem can occur where angular distortion occurs during cooling. In this study, to reduce weld deformation and form uniform back beads that angular distortion was measured using ceramic backing and Cu backing using GTAW with ER70S-60 C-filler. Angular distortion was measured according to welding speed for the same deposition area for each kind of backing. And we also examined the angular distortion phenomenon in relation to the type of backing.