Two-dimensional arc stagnation pressure measurements for the double-electrode GTAW process

Abstract

Double-electrode gas tungsten arc welding (GTAW) is a relatively new GTAW variant that has been studied and developed over recent years, with the aim being to achieve a robust high-speed and high-current process with subsequent productivity improvements. In this present study, two-dimensional arc stagnation pressure measurements were performed, allowing a broad visualisation of the arc pressure distribution at the area above the welding torch, with a 0.5 mm resolution. The influence of the distance between the electrodes was evaluated and the results were compared with the conventional GTAW process. It was found that this distance greatly modifies the resulting arc morphology and, consequently, the arc pressure distribution. The results showed that the double-electrode process has much lower pressure than the single-electrode GTAW, for example, using the minimal possible distance between the electrodes results in about half of the maximum pressure measured for the single electrode, which would enable the development of high productivity applications.