EMS-CO2 Welding: A New Approach to Improve Droplet Transfer Characteristics and Welding Formation

In this article, to improve the stability of droplet transfer and reduce the spatter of pure carbon dioxide gas shield welding (CO2 welding), we propose a new welding method called EMS-CO2 welding by applying an additional longitudinal electromagnetic field to a CO2 welding process (abbr. EMS-CO2 welding). The characteristics of droplet transfer, welding formation and microstructure between EMS-CO2 welding and general CO2 welding on a Q235 low carbon steel plate are studied. The results show that EMS-CO2 welding improves droplet transfer process, increases the stability of droplet transfer, and delivers better control of the welding spatter. Meanwhile, EMS-CO2 welding generates welding formation with refined grains, welding seams with uniform microstructure, and welding joints with a higher quality. Therefore, EMS-CO2 welding stands for the state of the art in short-circuit transfer CO2 welding especially.