Influence of Out-of Phase Current Pulse in the T-GMAW Pulsed Process Stability with Different Wire Feed Speeds

Abstract

One of the possibilities of variation of the Tandem GMAW process is the use of out-of -phase current pulse, with the aim of giving greater stability to the voltaic arcs. In some works available in the literature, the authors found results that showed that this effect of out-of -phase current pulse was not significant. Another aspect that is also widely defended in pulsed GMAW welding is the condition of a drop per pulse with droplet diameter close to the electrode, but T- GMAW configuration using electrodes with different feed speeds, it is not possible to maintain simultaneously the out-of -phase current pulse and the condition of one drop per pulse on both electrodes. The results obtained in this work showed that, for welding made with T-GMAW process with different feed speeds, the use of out-of -phase current pulse became determinant for arc stability and for the quality of the weld bead itself with distinct droplet diameters between the two wires and larger than the diameter of the electrode.

Key-words:
Tandem GMAW; Out-of-phase current pulse; Droplet diameter