| 摘要 |
PROBLEM TO BE SOLVED: To provide a bond flux for submerged arc welding which is capable of obtaining a weld metal with excellent toughness even at a low temperature of about -40 deg.C to -60 deg.C in the large heat input welding of >=50 kJ/cm. SOLUTION: A bond flux contains, by weight, 20-35% MgO, 5-15% Al2O3, 10-30% iron powder, 5-20% SiO2, 3-10% CaF2, 5-15% TiO2, 3-10% CaO, 2-8% CO2, 0.5-3% Al, 0.5-3% Mn, 0.2-3% total weight of at least one or two kinds selected from the group consisting of Si and Ti, and 0.1-2% B2O3, and the weight ratio CaO/TiO2 of CaO to TiO2 is 0.4 to 0.9.
|
