| 摘要 |
PROBLEM TO BE SOLVED: To provide a flux for one side submerged arc welding capable of providing a sound top bead shape and mechanical performance.SOLUTION: The flux for one side submerged arc welding has a composition which contains 6 to 12 mass% of Si, Si alloy and Si oxide (SiOreduced value), in total, 3 to 9 mass% of CaO, 15 to 35 mass% of MgO, 5 to 23 mass% of TiO, 2 to 10 mass% of CaF, 5 to 23 mass% of AlO, 2 to 9 mass% of CO, 0.5 to 3 mass% of NaO, 0.1 to 1 mass% of BO, 0.2 to 1 mass% of Mo and 10 to 30 mass% of iron powder, and contains Mn, Ti and Al which are respectively regulated into 0.9 mass% or less, 1 mass% or less and 3 mass% or less. In the composition, a constitutional proportion of iron powder having a particle size of 300 μm or less is 90 mass% or more in the iron powder and, when the content (mass%) of MgO is [MgO], the content (mass%) of AlOis [AlO], the content (mass%) of TiOis [TiO] and the content (mass%) of iron powder is [Fe], the composition satisfies the following expression (1). |
