Study on Penetration Form Using Stationary TIG Arc : Study on Low Speed DC-TIG Welding Method

Abstract

Generally, in TIG arc welding method, the ratio of penetration depth (D) to bead width (W) is small and the deep penetration cannot be obtained comparatively. But in the case of using the stationary TIG arc when the welding conditions were set to the suitable range, the value of D/W is closer to unity and the penetration depth becomes deep. Paying attention to the above mentioned phenomenon, the authors have made researches into the practical application of the stationary TIG arc.In this paper, the welding conditions which we obtained from the above mentioned penetration forms were investigated using SUS304. It was found out that when suffer (S) content of the base metal is more than 0.005 mass%, both the method of using the electrode with at vertex angle above 60° or with in argon shielding gas and the method of using helium to shielding gas are successful to increase the penetration depth.In the case of using the base metal which contains sulfer about 0.001 mass%, the method of using the tip-cutting electrode in argon shielding gas is more effective for same purpose.