Investigations on temperature distribution during revolutionary and zigzag movement of arc in magnetically impelled arc butt welding of tubes

Abstract

The arc in MIAB welding process follow two paths of motion, one along the circumference and other comprising the zigzag motion when commuting between outer diameter and inner diameter. The moving arc dissipates necessary heat such that the butt ends reach solidification followed by forging. In this study, a pivotal attempt is made to investigate the temperature distribution during the movement of arc along and across the faying surfaces using finite element method. MIAB welding process involves an arc created by the power source moving between the two fay- ing surfaces of tubes with the help of a magnetic field. An electric arc generated between aligned and properly gapped pipes is made to rotate along the peripheral butt ends. This arc swiftly rotates along the peripheral edgesof the tubes to be welded due to the electromagnetic force resulting from the interaction of the arc current and the externally controlled magnetic field created by magnetic systems. The arc acts as a heating source providing the required heat to the butt ends of the pipes. Further an application of force on the pipe along the axial direction sets the weld. The electromagnetic force responsible for the arc rotation is governed by the magnetic flux density in the gap, the arc current and the arc length (gap size). This section presents a comprehensive overview of the earlier research work carried out in the area of MIAB welding. Steffen et al. (11) investigated a variety of conditions and their effect on arc behaviour, including the use of internal and externalmagnetsand different powersources.Thearc was seento move