Special features of coldwire gas metal arc surfacing

Abstract

To study the features of GMA surfacing with the supply of an additional cold filler wire, the bead welding at different wire feed rates with different arc polarity are performed, at which the arc current and the current flowing from the electrode wire to the base metal are measured. It is determined that with the reverse polarity of the arc, the normal formation of the welding bead is ensured with a slight penetration of the base metal, while with the direct polarity, the heat release on the base metal is insufficient to form a bead of an acceptable shape, and the process is accompanied by significant spatter. It is established that during the feeding at an angle of 45°, the feed rate of the filler wire, which ensures that the wire is being melted in the center of the arc, is 1.4 times greater than when feeding is occurring at an angle close to 90°. In this case, the filler wire is melted due to the plasma radiation of an arc, and not by the current flowing through it.