Submerged arc welding melt highly basic flux

Used to create a high-strength weld metal, no top Suraguin healthy high toughness of the weld metal can be obtained, providing a highly basic melt flux for the submerged arc welding. Melt flux for the submerged arc welding used in the base material tensile strength seam welding the UO steel pipe for pipelines 800MPa~1200MPa is the mass%, CaO: 5.0% or more 25.0% or less, MgO 1.0% to 5.0% or