| 摘要 |
PROBLEM TO BE SOLVED: To provide a flux for submerged arc welding which provides good welding work efficiency and achieves reduction in a diffusible hydrogen quantity in weld metal, even if a welding power source is any of an AC type and a DC type.SOLUTION: The flux for submerged arc welding has a composition containing MgO:25-35 mass%, F(a CaFconversion value):15-30 mass%, AlO:10-25 mass%, SiO:10-20 mass%, at least one of Na(an NaO conversion value) and K(a KO conversion value): 0.5-5.5 mass% in total, Fe(an FeO conversion value):0.5-5 mass% and TiO:1-5 mass%, CaO regulated to 6 mass% or less, Mn(an MnO conversion value) regulated to less than 2.0 mass%, and water soluble SiOregulated to 1 mass% or less, the composition satisfying the following numerical expression (I). |
