ELECTROGAS ARC WELDING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an electrogas arc welding method which in electrogas arc welding of a vertical butt welded joint having a steel plate as a welded material bent in mount shape around a weld line toward a groove back surface, allows the steel plate to be welded without causing weld defect in a root bead even though temporary fitting accuracy of the steel plate is somewhat poor.SOLUTION: There is provided the electrogas arc welding method in which a vertical butt welded join in which a steel plate as a welded material is bent around a weld line in mound shape at angles &thetas;w ranging from 140 to 170° is arranged with a back side of a groove turned inward, is welded by arranging a fixed backing material and a water-cooled slidable copper backing on the back face and the front face of the groove respectively and using a consumable electrode. In the electrogas arc welding method, the welding is performed by arranging the fixed backing material that is formed in such a way that inside angles &thetas;b of a face opposing to the steel plate of the fixed backing material are between (&thetas;w-28)° and (&thetas;w-2)°.