Prediction of energy source properties of free-burning arcs

Energy source properties of gas tungsten arc (GTA) strongly depend on physical property of a shielding gas. For its low electrical conductivity, helium (He) is employed as a shielding gas for conditions requiring high productivity in GTA-welding process. However, the high cost of He limits its applications. Therefore, an alternative shielding gas with lower cost and better energy source properties is required. In this paper, carbon dioxide (CO2) was used as an alternative gas for its low cost. The basic energy source properties of CO2 GTA were numerically predicted ignoring the oxidation of the electrodes. It was predicted that CO2 GTA would have excellent energy source properties comparable to that of He GTA.