2005 Volume 23 Issue 4 Pages 515-525
In the tandem pulsed GMA welding, the occurrence of arc interruption by the electromagnetic interference between the two adjacent arcs becomes a problem. In order to clarify this problem, effects of inter-wire distance and Ar+CO2 gas mixture ratio on an abnormal arc voltage and arc interruption by the electromagnetic interference, are investigated. The abnormal arc voltage and the arc interruption frequently occur with pulse peak currents are supplied alternately to two wires. In addition, both phenomena occur in trailing arc which is located on molten pool at base current duration remarkably. There are most number of abnormal arc voltage and arc interruption times in trailing when the inter-distance is 10 mm because a displacement of trailing arc by the electromagnetic interference becomes the longest. Moreover, the CO2 mixture ratio affects the occurrence of abnormal arc voltage and arc interruption. The abnormal arc voltage and arc interruption do not occur when CO2 gas mixture ratio is equal to or less than 5%. However, number of abnormal arc voltage and arc interruption times increase rapidly with increasing CO2 gas mixture ratio when CO2 gas mixture ratio is over 10%.
