Analysis and Improvement of Metal Transfer Behaviors in Consumable Double-Electrode GMAW Process

Abstract

A nalysis and Im p ro vem en t of M e ta l T ran sfer B ehaviors in C onsum able D ouble-E lectro de G M A W ProcessConsumable double-electrode gas metal arc welding (consumable DE-GMAW) is the effi cient improvement of DE-GMAW. Due to the variety of coupled arc and metal transfer behaviors, this paper applies static force balance theory to analyze the changes in the forces acting on the main and bypass droplets separately. For main torch, the bypass arc changes the forces affecting on the main droplet, and the main metal transfer becomes more desirable. For bypass torch, with direct current electrode negative (DCEN) polar ity, the volume of droplet is big and not easily transfers to the weld pool. In order to improve the bypass metal transfer, a method has been proposed which adds CO2 to pure argon shielding gas to change the forces affecting on the bypass droplet. Then, the welding experiment is carried out to test the effectiveness of this method. It is found that bypass droplet transfers easily and the diameter of bypass droplet is decreased significantly. Also a good weld appearance is acquired.

Arc characteristics and metal transfer behavior of twin-arc integrated cold wire hybrid welding

“…At this moment, the droplet did not frequently contact the weld pool, but it was closed to the weld pool surface. Therefore, the droplet would be subjected to the greater resistance generated by the metal vapor from the weld pool, which greatly increased the difficulty of droplet detachment and made the droplet kept at the wire end to grow up [22]. Moreover, the droplet size has a noticeable effect on the component forces of surface tension, i.e., F σ(0) and F σ(r) .…”