| 摘要 |
The present invention provides a bonded flux for submerged arc welding, which can obtain welding metal with high welding operability and high toughness even though welding construction for low-temperature steel is carried out by means of a narrow groove. The bonded flux for submerged arc welding contains 25-45 mass% of MgO, 5-25 mass% of Al_2O_3, 5-25 mass% of CaF_2, 2-10 mass% of metal carbonates, total 2-10 mass% of CaO and/or BaO, total 2-10 mass% of at least one among metal Si, Si alloy, and Si oxide, total 0.3-2.0 mass% of at least one among metal Ti, Ti alloy, and Ti oxide, total 0.05-0.3 mass% of at least one among metal B, B alloy, and B oxide, and 0.005-0.15 mass% of S; and moreover, the total content of metal Al and Al alloy is limited below 0.1 mass%. Additionally, the total content of metal Si and Si alloy is 0.3-2.0 mass%, and the total amount of Si/Ti is in the range of 5-15. |
