Analysis of Electrical Characteristics of Inter-wire Arc in Cross-Coupling Arc

Abstract

As a new composite welding heat source introduced in recent years, the cross-coupling arc uses a non-consumable electrode arc (plasma arc) and a consumable electrode arc (inter-wire arc) in cross-coupling, in which the plasma arc is the main arc and the inter-wire arc is the vice arc, to realize the separate control of the heat input to the workpiece, arc force, and droplet transfer. To reveal the electrical characteristics of the inter-wire arc under the action of the plasma arc, in this study, rotating probes are used to sweep across the plasma arc. When the probes rotate into the plasma arc, a circuit is formed, and the electrical characteristics of the inter-wire arc are indirectly analyzed according to the circuit: the probe centering current and input voltage are used as the physical quantities. The results show that at a certain wire feed rate, the inter-wire arc current increases with increasing input voltage. When the input voltage is low, the wire feed rate has no obvious effect on the inter-wire arc current. At a higher input voltage, where the wire feed rate is high, the inter-wire arc current decreases. With the increase in the plasma arc current, the inter-wire arc current first increases quickly and then increases slowly, and simultaneously, the striking arc time becomes longer. With the increase in the interval between the nozzle and the workpiece, the inter-wire arc current increases, but when the arc length increases to a certain limit, the slope of the welding current clearly declines.

Study on the Decoupled Transfer of Heat and Mass in Wire Variable Polarity Plasma Arc Welding

“…In this method, a variable polarity arc can be established between two wires by loading a variable polarity welding supply to a tandem GMAW system. Lu et al [23] proposed cross-coupling arc welding, which can decouple the heat and mass transfer by cross coupling a GTAW arc and GMAW arc. In this process, one arc is formed between the tungsten electrode and base metal, while the other one is formed between the two wires.…”

Influence of Polarity Arrangement of Inter-Wire Arc on Droplet Transfer in Cross-Coupling Arc Welding

“…At present, the research on cross-coupling arc welding mainly focuses on arc stability, arc behavior, and droplet transfer [20,21,22,23,24], especially arc stability tests playing a primary role in the development of welding processes, which is an important mean to determine whether the arc can perform effective thermal output and whether the droplet transition is stable [25,26]. However, it is found that there is an obvious polar zone phenomenon in the study of cross-coupling arc stability, that is, the main arc is regularly inclined to the polar zone of the IWA.…”