PURPOSE:To obtain the defect-free joints at high efficiency in the captioned welding of plates by specifying groove shape, the thickness of the one layer one pass except the final layer, the diameter of a wire, the welding current per electrode and welding speed. CONSTITUTION:The groove of the works A, A' is approximately of square shape and its bottom width WB is made 6-14mm and the width WF on the surface 20mm or less, these being made WB=WF. A wire E of 1.0-4.0mmphi in granular flux F as a consumable electrode is disposed in the approximate center of the groove width and submerged arc welding is done by generating arc from this. As the welding conditions for these, the welding current is made 150-700A per electrode, the welding speed 15-40cm/min and 20-70cm/min respectively in the case of single electrode and 2 electrodes and deposition thickness=deposition sectional area/groove width 3-6mm. As a result of this, the penetration P to base metals become as shallow as 1mm or less and the dilution of the base metals decreases considerably down to about 20% or less. Hence, the amount of entry of Nb and V in the base metals into weld metal B is considerably reduced and the weld metal becomes tougher.
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