Selection of Shield Gas in Gas Shield Arc Welding

The shield gas play an important role in the gas shield arc welding. It not only prevent the welding pool from oxidized and the composition element melt loss, but also affect the droplet transition and the distribution of the arc power between the cathode and the anode. This paper introduce the different results in GTAW, which using different shield gas. And the selection principle of shield gas in different metals GTAW is discussed. In GMAW, the droplet transition is more important than welding pool shielding, the changed composition of the shield gas could induce the droplet transition change, and the quality of welding seam will be changed. So the most suitable shield gas should be used in the welding production in order to gain satisfied welding quality, efficiency and cost. And the development trend of the shield gas in gas shield arc welding was discussed.