| 摘要 |
Provided is a flux which is for use in submerged arc welding and which can ensure good welding operation in both cases using respectively an alternating-current welding power source and a direct-current welding power source and which can reduce the diffusible hydrogen content of a weld metal. This flux for submerged arc welding has a composition which comprises 25 to 35mass% of MgO, 15 to 30mass% of F (in terms of CaF2), 10 to 25mass% of Al2O3, 10 to 20mass% of SiO2, 0.5 to 5.5mass% in total of Na (in terms of Na2O) and/or K (in terms of K2O), 0.5 to 5mass% of Fe (in terms of FeO), 1 to 5mass% of TiO2, at most 6mass% of CaO, and less than 2.0mass% of Mn (in terms of MnO) with the content of water-soluble SiO2 being 1mass% or less and which satisfies numeral formula (I). |
