Effect of polarities and shielding gases in CWW GMAW

ABSTRACT

The effect of polarity and shielding gases on the droplet transfer behavior and formation trend of cable-type welding wire gas metal arc welding was studied under the same welding parameters. An acquisition system was used to observe welding parameters, droplet transfer and arc behavior. The results showed that the arc shapes with different polarities under the same shielding gas were different. The arc length and width in direct current electrode positive (DCEP) mode were smaller than those in direct current electrode negative (DCEN) mode. For the same polarity and different shielding gases, with increasing CO₂ gas content, the arc length and width gradually decreased. In DCEP mode, droplet transfer was characterized by globular and projected droplet transfer modes. The droplet transfer modes with different polarities differed under different shielding gases. The droplet transfer mode was basically the same for the same polarity. With increasing CO₂ content, the weld bead formation gradually improved.

KEYWORDS:

• CWW
• GMAW
• polarity
• gas
• arc
• droplet
• formation

Acknowledgments

This work was supported by the National Natural Science Foundation of China (Grant No. 51905231), China Postdoctoral Science Foundation fund project (Grant No. 2020M670943).

Disclosure statement

No potential conflict of interest was reported by the authors.