BUTT WELDING METHOD OF SINGLE VEE GROOVE WITH BROAD ROOT FACE TO PREVENT GENERATION OF BLOWHOLE

摘要

PURPOSE:To prevent thoroughly generation of a blowhole by an easy means and to reduce time with omission of a back chipping stage by performing root pass so as to melt thoroughly the root face from the rear side. CONSTITUTION:Blank materials 1 to be welded have a root face in the groove and when the materials are subjected to root pass from the rear side, a deposited metal 7 melts thoroughly the root face. Welding of the 2nd layer is accomplished from the front side in this state by which the weld zone having no blowhole is obtd. The quality in the weld zone is thus improved and the working time is reduced.