Analysis and Characterization of the Weld Pool and Bead Geometry of Inconel 625 Super-TIG Welds

Abstract

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.