A method of submerged arc welding using thick heat steel for large heat input and a flux for submerged arc welding

摘要

A method of submerged arc welding of thick steel plates with a large heat input and flux for submerged arc welding which comprises: forming a groove having a multi-angle shape which has at least two different angular inclination when a single side submerged arc welding for perfect penetration is conducted under a condition of an welding heat input of 100 to 1000 kJ/cm; using submerged arc welding flux SiO2: 5 to 28% by weight, MgO: 15 to 35% by weight, CaO: 5 to 15% by weight, CaF2: 2 to 20% by weight, Al2O3: 5 to 15% by weight, and TiO2: 2 to 10% by weight as the main components, and containing iron powder by 30% by weight or less and either or both of Si and Mn in the metallic form by 10% by weight, the submerged arc welding flux having a particle size distribution arranged such that the proportion of the particle size distribution arranged such that the proportion of the particle which have a size finer than 36 mesh is 20% by weight or less and the proportion of the particles which have a size 14 mesh or finer but 36 mesh or rougher is 60% by weight or more; and conducting the welding.