| 摘要 |
Provided are melt flux for submerged arc welding and a method for submerged arc welding of steel for low temperature service, wherein a weldability is good and a weld metal having an excellent mechanical properties is obtained even in a welding condition at high speed. The melt flux containing Si0 2 : 8 to 25%, Al 2 O 3 : 30 to 50%, MgO: 0.5 to 5.0%, MnO: 0.5 to 5.0%, CaO: 5 to 20% and CaF 2 : 25 to 50% by mass is combined with and submerged-arc-welded with a flux cored wire wherein the wire contains C: 0.02 to 0.30%, Si: 0.08 to 0.6%, Mn: 1.2 to 3.0%, Ni: 0.5 to 3.5%, Mo: 0.03 to 0.8% by mass in its entire amount and the filled flux contains C: 0.01 to 0.27% and CaF 2 : 2 to 15% by mass, wherein a total amount of hydrogen in the wire is 50 ppm or less and wherein there is no seam on the steel sheath filled with the 10 to 30% flux in the component. |
