Effect of Current Phase on Tandem Wire Pulsed MIG High-Speed Welding

Magnetic field distribution model of tandem wire pulsed MIG high-speed welding was established, so was model of electromagnetic force on droplet. Through analyzing on parameters of the magnetic field of arc space, it was found that magnetic field intensity generated by arc and current were linear dependence, when current pulses of tandem wire were not overlapped, magnetic blow caused by parallel arc was minimum. Through analyzing on parameters of the model of electromagnetic force on droplet, it was found that the unit electromagnetic force on droplet and current product of the tandem wire were linear dependence, when the current pulses of tandem wire were not overlapped, the electromagnetic force on droplet was the least, and deviate distance of droplet trajectory was also minimum. Finally, contrast experiments of in-phase, random-phase and anti-phase current pulse were carried out by self-developed multifunctional tandem wire welding machine. The results indicated: when the current pulse of leading torch and tracking torch were not overlapped, the welding process was stable, and the weld was perfectly formed.