Effect of double-wire narrow gap GMA welding parametars on weld appearance

The influences of three parameters which are space between wire and edge, space between two wires and angle between two wires on weld appearance were studied in double-wire narrow gap welding with one pool by procedure experiments.The results show that the increase of space between wire and edge can make sidewall penetration and saucer shape of weld surface increase. When the arrangement of wires became parallel, sidewall penetration and saucer shape of weld surface increased to the maximum value. When space between wires increased, sidewall penetration and saucer shape of weld surface increased firstly and then decreased, and finally arrived at peak value when the space between wires is 5-10 mm under the co-action of arc and molten pool energy.But when there was no finger penetration, the three procedure parameters mentioned had little influence on weld penetration.There was lack of fusion of weld bottom when I-shape groove was adopted, and adjusting the three parameters could not eliminate the phenomenon of non-fusion.