Abstract: Characteristics and arc stability of multi-arc morphology in multi-wire welding are significantly different from those of single-wire welding due to electromagnetic force. A triple-wire welding platform was established, and the influence of welding current and wire-to-wire distance on arc shape characteristics was quantitatively studied by using the triple-wire welding high-speed photographic system. The fluctuation values of arc shape parameters (arc height, arc area, and arc deflection) were used to evaluate arc stability. The results show that there is no obvious fluctuation in arc height, and its value is related to welding current, but independent of wire-to-wire distance. When the welding current is set at a high level, there are more molten pool metals, which cause the “submerged arc phenomenon”, and the height and area of the arc become smaller than those at a low level of welding current. In addition, the arc under the high current condition has a strong anti-interference ability. Therefore, the arc deflection is small, and the arc combustion is stable. The change of wire-to-wire distance has a more direct effect on the middle arc area than that of leading arc and trailing arc. Overall, the interference effect and deflection of arc decrease and the arc stability improves as the wire-to-wire distance increases.

Key words: triple-wire welding, arc height, arc area, arc deflection