Arc phenomenon and core wire fusion in twin electrode single arc welding

Abstract Arc phenomenon and core wire fusion in the twin electrode single arc welding (TESAW) are observed by a high speed digital camera. Arc voltage and arc current are measured by an oscilloscope. Main results of the experiment are summarised as follows: the TESAW arc fluctuates periodically with a period of 20–40 ms in this study and, correspondingly, arc voltage is also changed periodically. The variation in arc voltage is large, but arc current does not vary so much. Arc voltage fluctuates mainly above a certain value, corresponding to the motion of the arc under normal welding condition, but short circuiting does not occur. Arc root of TESAW locates at the droplets of the core wire tip, and the formation, growth and transformation of the droplets induce the change of arc shape and fluctuation of arc voltage. The fluctuation of arc voltage and the fusion of core wire depend on the factors such as the two core span, welding current and electrode type.