Correlation between Arc Phenomena and Welding Parameters in Submerged-Arc Welding

In submerged arc welding, the direction of arc column and the position of molten metal in the crater have been examined using a X-ray image intensifier TV system in order to regulate weld bead shape by controlling welding parameters.Arcs are classified into the open and buried arcs depending on the position of electrode tip to the plate surface. The arc at high welding current and high travel speed, is buried in the plate and is generated forward between the front of crater and the electrode tip, which results in a knife like shape of electrode tip. The arc at high welding current and low travel speed, is buried deeply in the plate and strikes radially between the weld pool and the electrode tip melted like a pencil. On the other hand, the open arc with low welding current is generated between the weld pool and the electrode tip over the plate surface. The direction of the arc column and the shape of the electrode tip at the open arc change in accordance with the position of molten metal in the crater.