Submerged arc welding method of low-alloy steel with excellent resistance to sulfuric acid and hydrochloric acid resistance

摘要

PROBLEM TO BE SOLVED: To provide a submerge arc welding method for obtaining a weld metal exhibiting excellent corrosion resistance etc. under the environment of concentrated sulfuric acid and concentrated hydrochloric acid and having no welding defect.;SOLUTION: Welding is performed by using the combination of a bond flux and a solid wire. The bond flux contains, by mass%, 5 to 21% of SiO₂, 15 to 44% of Al₂O₃, 7 to 32% of MgO, 0.5 to 10% of CaO, 5 to 35% of CaF₂, 5 to 33% of TiO₂, 0.2 to 5.0% of Si, 0.1 to 5.0% of Mn, and 0.5 to 9.0% of CO₂ in terms of metal carbonate. In bond flux, particles having a particle diameter exceeding 850 μm account for 20 to 55%, particles between 150 and 850 μm for 40 to 75%, and particles less than 150 μm for 6% or less, and the apparent density is 0.70 to 1.30 g/cm³. The solid wire contains 0.005 to 0.2% of C, 0.01 to 1.5% of Si, 0.4 to 2.5% of Mn, 0.03 to 1.0% of Cu, 0.05 to 1.0% of Ni, 0.01 to 1.0% of Mo, and 0.01 to 0.25% of Sb.;COPYRIGHT: (C)2013,JPO&INPIT