Abstract
In tandem pulsed GMA welding the stabilization of accumulated molten metal between the leading arc and the trailing arc, the presence of enough molten metal below the trailing arc, and the reduced velocity of molten metal flow towards the rear part of the weld pool are essential to improve the maximum welding speed. These conditions can be attained by adjusting the ratio of the leading arc current to the trailing arc current. A maximum welding speed as high as 4 to 4.5 m/min is achieved by setting the current ratio to a value ranging from 0.31 to 0.5, which corresponds to an reduction in average velocity of molten metal flow at locations 4 to 7 mm behind the trailing arc.
