| Plasma-MIG hybrid arc welding is a promising technology in material processing, and the properties of this method should be well investigated. A power supply and control system for hybrid plasma-MIG arc welding is developed in this paper. Surfacing welding is conducted on low-carbon steel with H08Mn2Si filler metal, and the relationship of droplet transfer, weld appearance with the arc voltage and current are researched utilizing high speed video and voltage/current data acquisition system. The results show that in Hybrid plasma-MIG arc welding process, MIG arc and plasma arc are coupled with each other by sharing the electric-magnetic field, gas plasma zone and filler metal. Self-regulating property can reduce arc voltage and current fluctuation in the droplet transfer stage, and therefore a stable arc and little sputtering are realized. The wettability of base metal and filler metal are enhanced by the pre-heating effect of plasma arc on base metal, so the weld appearance is improved comparing with traditional MIG arc welding. The work can develop the hybrid high efficiency welding theory and are important for Hybrid plasma-MIG arc welding technology in further practical application. |
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