Optimization of GTAW Parameters for Horizontal Welding of a STS316L Pipe

Lee, Hyoung-Keun; Bang, Kyoung-Sik

doi:2015.33.5.47

JWJ > Volume 33(5); 2015 > Article

Research Paper

Journal of Welding and Joining 2015 October;33(5) :47-52.
Published online October 30, 2015.

doi:https://doi.org/10.5781/JWJ.2015.33.5.47

Optimization of GTAW Parameters for Horizontal Welding of a STS316L Pipe

Hyoung-Keun Lee^*, Kyoung-Sik Bang^**

^*Dept. of Advanced Materials Engineering, Hanbat National University, Daejeon, 305-719, Korea
^**Fuel Cycle System Engineering Technology Development Dept., KAERI, Daejeon, 305-353, Korea

Correspondence: Hyoung-Keun Lee Email: leehk@hanbat.ac.kr
Published online October 30, 2015

ABSTRACT

In this study, it was tried to analyze the effects of welding parameters on the weld penetration and aspect ratio when a STS316L pipe was welded in a horizontal position by GTAW. Experiments were systematically designed using a L18 orthogonal array, and the effects of welding parameters were statistically analyzed by ANOVA(Analysis of Variance). The shielding gas type has the largest effect on both the penetration and aspect ratio. The welding current type and shielding gas flow rate have a little effect on the penetration, whereas the electrode tip angle has a little effect on the aspect ratio. When welded at a selected welding condition, which is composed of He shielding gas, pulse current of 300/45 A, electrode tip angle of 90o, and shielding gas flow rate of 30 l/min, the estimated interval at least 95 % confidence was 1.99 ± 0.18 mm for the penetration and 0.31 ± 0.04 for the aspect ratio. From the confirmation experiments, the average penetration and aspect ratio were well agreed with the estimation as 1.96 mm and 0.30, respectively. Additionally, the effects of the welding speed and welding current on the penetration and aspect ratio were experimented and analyzed by linear regression. The penetration was linearly increased with the decrease of the welding speed and with the increase of the welding current, but the aspect ratio showed a tendency to a little decrease with the increase of both the welding speed and current.