| 摘要 |
PURPOSE:To form with high efficiency a weld metal which is excellent in its cold toughness, by forming plural molten pools which are separated suitably by use of a flux of a specified composition and plural electrode wires of a specified composition, and executing submerged arc welding. CONSTITUTION:A flux 2 containing 10-70% iron powder and/or alloy powder, 3-30% TiO2 and/or 0.3-2.0% Ti, and 0.1-1.0% B2O3, based of the whole flux, and electrode wires 3, 4 and 5 containing 0.8-3.2% Mn and 0.15-0.75% Mo are used, a preceding molten pool 8, a molten slag 11 and a soldified slag 14 are formed by the preceding electrode wire 3, and a following molten pool 9, a molten slag 12 and a solidified slag 15 are formed by the following two electrode wires 4, 5, by which a base metal 1 is submerged arc-welded in a welding direction 16. In this case, a mutual interval between the electrode 3 and the electrode group 4, 5 for forming each molten pool 8, 9 is set to >=300mm., and also the following molten pool 9 is formed by two electrodes 4, 5 placed within 60mm.. |
