A comparison of double shielded GMAW-P with conventional GMAW-P in the arc, droplet and bead formation

Double shielded pulsed gas metal arc welding (D-GMAW-P) was proposed to feed the shielding gas of Argon (Ar) and carbon dioxide (CO2) with two independent coaxial channels. The molten pool was protected from blowholes by improving the flow rates of shielding gas in the inner channel and outer channel. The feeding of Ar in inner channel and CO2 in outer channel made the current density distribution of the double-shielded arc generate a strong...