METHOD FOR REDUCING WELDING DISTORTIONS, DETERMINED FOR A SINGLE-SIDED FLAP JOINT

摘要

This invention relates to a welding deformation reducing method for a case where steel plates to he welded are set face to face with each other, the abutted portions of the plates being tack welded, one-side strap joint welding of the tack welded portions being done thereafter. In the welding deformation reducing method according to the present invention used when one-side strap joint welding is carried out, when not less than three welding electrodes are used, when Qi is welding heat input of each electrode which is determined on the basis of amperage, voltage and speed and Li the distance between a first electrode and each electrode, and when a maximum value H of the height of a tacked bead is set to be not more than a half of the thickness of the steel plates to be welded, the welding conditions are determined so that a value of a parameter P (P = 1/H SIGMA Qi/(Li + k)) becomes not higher than a predetermined level. In order to carry out tack welding using a tab plate as well, P is set not higher than a predetermined level, and the height Ht of tack welded bead of a tab plate not more than a half of the thickness of the steel plates to be welded, the welding conditions being determined so that Ptab obtained by substituting the resultant values for H has a value not less than a predetermined value. IMAGE