Development of swing arc narrow gap GMAW process assisted by swaying wire

In order to further raise narrow gap welding efficiency while improving weld formation, a swing arc narrow gap GMAW process assisted by swaying wire is developed. This process swings the arc to increase groove sidewall penetration, and simultaneously adds a swaying wire to raise the welding deposition rate as well as modify the weld shape. The present work realizes a digital synchronous swaying control between the swing arc and the additional wire on the basis of kinematic modeling, and analyzes the characteristics of arc linear energy distribution in the groove. Arc behaviors, weld formation, and additional wire melting rate are then investigated for the cold wire assisted process. The reduction rates of weld layer number and welding time are also particularly proposed to evaluate the welding efficiency. Experimental results show that the developed process stabilizes the swing arc by attracting the arc to heat the additional wire in synchronous swaying, and yields good welds of sufficient penetrations and indistinctively-changed thickness even at fast feeding rates of the cold wire. Furthermore, the weld layer number and the welding time decrease respectively by -26% and -54% at most due to a 120% increase in the deposition rate, achieving a high-efficiency and high-quality narrow gap arc welding.