Development of Tungsten Electrode for TIG Welding

Abstract

Tungsten Inert Gas (TIG) welding process is mostly applied to high alloy steel pipes including stainless steels because of superior welding quality and gap bridge-ability than other welding processes. However, it has poor productivity due to low welding speed and deposition rate. In order to improve TIG welding productivity, high performance TIG welding with higher arc temperature, automation and high deposition rate system including hot wire have been developed. Higher arc temperature and longer welding time damage tungsten electrodes of TIG welding. It causes welding defect such as tungsten inclusion and short replacement cycle of tungsten electrodes. Various types of tungsten electrodes containing rare earth metal oxides (thorium, lanthanum, cerium, etc) were introduced to improve electrode erosion resistance and arc stability. In this study, their operation characteristics, arc starting performance, tip development, and electrode consumption were reviewed.