A Study on Process Characteristics and Performance of Hot Wire Gas Tungsten Arc Welding Process for High Temperature Materials
Hot wire gas tungsten arc welding (HW GTAW) process is the one where the filler wire is pre heated close to its melting point before it is fed in to the arc. The effect of HW GTAW parameters such as welding current, hot wire current and the wire feed rate during welding of super ASS 304H stainless steel tubes were evaluated in terms of heat input, voltage current (V I) characteristics and weld bead characteristics such as bead weight and geometry. The results obtained indicate that for a constant welding current, increasing the hot wire current and wire feed rate provides a stable V I characteristics and higher bead weight. Further, increasing the hot wire current and wire feed rate also provides better or desired weld pool and hence the bead geometry was described in terms of width, penetration depth, area of fusion and toe angle. By utilising the above knowledge, the tube to tube butt welding of SS 304H material was carried out. It was observed that, the weld joint is qualified as per the quality requirement of ASME: Sec IX standard.