Abstract:

The welding processes of two CO₂ arc-welding machines were tested and analyzed using a self-developed welding dynamic arc wavelet analyzer.The results indicate that the integrated electric characteristics of welding power can be reflected by the dynamic resistance,that the dynamic resistance should quickly increase to a stable value to make the striking successful,that the ripple interference of dynamic resistance should be reduced and the
peak value of dynamic resistance should remain constant in a certain period to realize a smooth droplet transfer in the welding process,and that the dynamic resistance should smoothly increase from the peak value to a infinite value in a transition cycle to avoid an abrupt ascend in the process of arc extinguishing.All these results lay a founda-tion for the improvement of arc welding technology and arc waveform control.

Key words: dynamic resistance, arc stability, spatter, waveform analysis, carbon dioxide arc welding