Abstract
"Uranami bead" formation with DCEN polarity -as a part of a study on one side narrow gap MAG welding- was investigated in the previous papery, in which the ranges of suitable welding conditions for good "Uranami beads" and the variation of the "Uranami bead" shapes under various welding conditions were also reported.
In this paper, the effects of various factors such as blowing angle, blowing point and flow rate of control gas, wire oscillation etc., on the "Uranami bead" shape of root pass in DCEN I-groove narrow gap welding of thick plate (22 mm), were studied.
It was found that in one-side narrow-gap MAG welding with DCEN polarity, a stable "Uranami bead" with improved shape could be obtained by directing the control gas onto the surface of the molten metal, using a specially designed torch.
