Multi-electrode submerged arc welding process with excellent weld bead shape

摘要

PROBLEM TO BE SOLVED: To provide a multiple electrode submerged arc welding method by which molten metal flowing to the rear part of the molten metal at high speed welding is effectively and efficiently restrained by utilizing electromagnetic action, and thus defect, etc., such as undercut, in a weld bead accompanying the speeding up of welding, is prevented.;SOLUTION: In the multiple electrode submerged arc welding method using AC as welding current of at least the rearmost electrode, to non-solidified welded metal part at the rear part of the rearmost electrode, AC magnetic field having the same frequency as the welding current of the above electrode, is impressed from the vertical and the right and left direction with respect to a weld line. Further, at least one among the magnetic flux density in the AC magnetic field, the frequency phase difference between the above AC magnetic field and the welding current of the above electrode and the impressed position of the above AC magnetic field, is adjusted to obtain the excellent weld bead shape.;COPYRIGHT: (C)2002,JPO