The influence of bypass current on arc energy density and metal transfer behaviour in bypass current compressed gas metal arc welding

Abstract

A new welding method, bypass current compressed gas metal arc welding (BCC-GMAW), was developed to enhance the arc energy density and welding stability of GMAW. When the bypass current was applied, the arc energy density was increased with the constraining effect of the circumferential bypass electrode, which was studied by current density and arc pressure, resulting in an increase of 46% in weld depth and a decrease of 38% in weld width. As the coupled arc increased the melting speed of wire and forces of droplet downward transfer, the droplet transfer frequency increased by 185%, and the metal transfer mode was changed from short-circuit transfer to stable small globule transfer, obtaining a smooth and uniform weld appearance.

KEYWORDS:

• Bypass current
• GMAW
• current density
• arc pressure
• metal transfer

Acknowledgements

The authors are greatly indebted to the State Key Laboratory of Science and Technology on Underwater Vehicle for the support of this research and the State Key Laboratory of Advanced Welding Production Technology for the tests and analyses conducted in this research. This work was supported by the National Nature Science Foundation of China [grant number 51975138]; the High-Tech ship Scientific Research Project from the Ministry of Industry and Information Technology ([2019]360).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by National Natural Science Foundation of China: [Grant Number 51975138]; High-Tech Ship Scientific Research Project from the Ministry of Industry and Information Technology: [Grant Number [2019]360].