| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a bonded flux for submerged arc welding excellent in weldability and providing high toughness weld metal, even when low temperature steel is subjected to welding procedure by a narrow groove.SOLUTION: The bonded flux for the submerged arc welding has a composition containing MgO:25-45 mass%, AlO:5-25 mass%, CaF:5-25 mass% and metal carbonate:2-10 mass%, CaO and/or BaO of 2-10 mass% in total, one kind of more of metallic Si, an Si alloy and Si oxide of 2-10 mass% in total, one kind or more of metallic Ti, a Ti alloy and Ti oxide of 0.3-2.0 mass% in total, one kind or more of metallic B, B alloy and B oxide of 0.05-0.3 mass% in total and S of 0.005-0.15 mass%, where the total content of metallic Al and an Al alloy is regulated to 0.1 mass% or less, and where the total content of the metallic Si and the Si alloy is 0.3-2.0 mass% and where the total Si quantity/the total Ti quantity is 5-15.</p> |
