| 摘要 |
PURPOSE:To reduce consumption of a welding wire and flux and to obtain a bead having substantial penetration and a smooth shape by specifying the ratio between the depth of a groove and root face and the respective electrode current ratios during welding of the front and rear surfaces at specific values. CONSTITUTION:The groove of steel plates is formed to the shape of a double Vee groove in the stage of welding steel plates having 12-39mm. thickness by a single layer submerged arc welding for double surfaces with multiple electrodes using 2-4 pieces of electrodes. The ratio between the depth of the groove on the front surface, the length of the root face and the depth of the groove on the rear side is set at 1:0.4-0.6:0.4-0.6. With regard to the conditions of respective electrode currents, the 1st electrode current is set at 1,000-1,200A and the respective electrode currents of the 2nd and succeeding electrodes are set at 0.8- 0.9 times the current of the electrode just before the same. The welding is performed under the conditions that the arc voltage of each electrode does not exceed 38V. |
