Characteristics of droplet transfer during ultrasound-MAG hybrid welding

The droplet transfer behavior during Ultrasound-MAG welding of low carbon steel is investigated in this paper. The test mainly focused on the change of droplet transfer behavior in low carbon steel welding under the effect of ultrasonic. Through observation and analysis of the droplet transition process, the results show that ultrasonic can change the distribution range of droplet transfer, the short circuit transfer is more adaptive to the voltage and current, large drop transfer voltage is increased and the instability of the transition has been improved under the moderate current voltage. For different transitional forms, ultrasonic can increase the frequency of the droplet transfer, change the size and shape of the molten drop and the molten droplet can be transited to the molten pool with smaller size and higher frequency. Compared with the conventional MAG welding, the ultrasound-MAG welding current signal fluctuation is smaller and the droplet transfer process is more stable. This study is an important supplement to the development and application of ultrasonic assisted arc welding technology.