Metal transfer characteristics of rotating arc narrow gap horizontal GMAW

The metal transfer process in rotating arc narrow gap horizontal welding is successfully observed by the high speed photography system. Because of the difference of the arc length induced by the molten pool surface shape in the rotating arc horizontal welding, the metal transfer has certain change regularity. In the weld width direction, the transfer frequency in the area of near both sidewalls is larger than that in the centre of the groove. In a rotating period, the transfer frequency in the downward motion process is larger than that in the upward motion process. The rotating arc process can improve the metal transfer. The results indicated that the centrifugal force induced by the arc rotating has great effect on the globular transfer mode which has lower transfer frequency and larger droplet size. Regarding the spray transfer mode, it has limited effect.