Solution to problems of arc interruption and arc length control in tandem pulsed gas metal arc welding

Abstract

In the tandem pulsed gas metal arc welding, it is the most important issue to prevent adverse effects caused by electromagnetic interaction between the two adjacent arcs to prevent arc interruption. A pulse timing control can reduce arc interference in tandem pulsed gas metal arc welding. One effective way is to delay the pulse end timing of trailing arc by 0·4–0·5 ms from that of leading arc. In addition, arc length control is assured by pulse frequency modulation for the leading wire and pulse peak modulation for the trailing wire with the pulse timing synchronised with the leading pulse. Consequently, leading and trailing arcs are maintained stable without arc interruption and a stable arc length control is established, which is hardly affected by fluctuations of wire feedrate and extension length.