Development of Low Spatter CO₂ Arc Welding Process with High Frequency Pulse Current

Abstract

In CO₂ arc welding of solid wire, metal transfer phenomena and spatter generation are investigated by with rectangular pulse current, and low spatter CO₂ arc welding process with high frequency pulse current is developed. The optimal conditions of high frequency pulse CO₂ arc welding are in the range of peak current : 450-550A and pulse frequency: 450-750Hz. These high frequency pulse currents have the effect of the droplet oscillation due to resonance between applied pulse frequency and the natural frequency of the droplet. The droplet is transferred consistently every 9-11 pulses and the average interval of metal transfer is about 16ms which is reduced to half than that of conventional CO₂ arc welding. This average droplet weight is 34mg, showing a large reduction in comparison with that of the conventional method. As a result, total spatter weight is reduced by 70% in comparison with the conventional method, and especially, large spatters more than 0.5mm in diameter are reduced from 1.5g/min to 0.2g/min.