| 摘要 |
Provided is a flux for submerged arc welding, which is capable of reducing the amount of diffusible hydrogen in a welded metal, while achieving good welding workability in both cases where an alternating-current power supply or a direct-current power supply is used for welding. This flux for submerged arc welding is configured to have a composition which contains 15-35% by mass of Al2O3, 10-30% by mass of SiO2, 10-25% by mass of MgO, 10-25% by mass of F (in terms of CaF2), 3-20% by mass of Mn (in terms of MnO), 0.5-4.5% by mass in total of Na (in terms of Na2O) and/or K (in terms of K2O) and 0.5-8% by mass of Fe (in terms of FeO), while controlling CaO to 6% by mass or less and water-soluble SiO2 to less than 1% by mass, and which satisfies mathematical formula (I). |
