Novel rotation arc system for narrow gap MAG welding

The present paper develops a hollow axis motor driven high speed rotation arc system for narrow gap welding ( NGW), and introduces the features of this system. Some welding experiments were then carried out to investigate the characteristics of welding wire melting and weld formation for this new process. Experimental results show that the melting rate of wire increases and the residual melting ball diameter of wire tip decreases respectively with an increase in rotation speed, and this melting rate is higher in pulsed welding and NGW respectively than in dc and flat plate welding. Furthermore, the arc rotation can obviously improve the penetration into NGW groove sidewalls and bead shape, and thus the system has been used to weld practical NGW joints successfully.