The effects of double groove type on the backing weld penetration in swing arc vertical-up MAG welding

Abstract

The penetration of the bead for swing arc vertical-up backing welding was investigated by experiments and numerical simulations in the present work. Three double groove types were used: double V groove, one V-one trapezoid groove, and double compound angle groove. The molten pool behaviors and the weld-forming mechanisms for different grooves were studied. The results indicate that the groove assembly dimensions affect the penetration of the backing weld. As the root gap increases or the root face decreases, the penetration increases. For one V-one trapezoid groove, the increase of the groove width leads to the decrease of the penetration. Based on the analysis of the weld-forming mechanisms, a double compound angle groove was proposed and applied, and a better full penetration can be obtained. Through the analysis of simulation results, the optimized groove for double-sided swing arc vertical-up metal active gas (MAG) welding was obtained.