METHOD OF SUBMERGED ARC WELDING A THICK STEEL PLATE WITH LARGE HEAT INPUT AND SUBMERGED ARC WELDING FLUX

摘要

ABSTRACT OF THE DISCLOSUREA method of submerged arc welding of thick steel plateswith a large heat input and flux for submerged arc weldingwhich comprises: forming a groove having a multi-angle shapewhich has at least two different angular inclination when asingle side submerged arc welding for perfect penetration isconducted under a condition of an welding heat input of 100to 1000 kJ/cm; using submerged arc welding flux SiO2: 5 to28 % by weight, MgO: 15 to 35 % by weight, CaO: 5 to 15 %by weight, CaF2: 2 to 20 % by weight, Al2O3: 5 to 15 % byweight, and TiO2: 2 to 10 % by weight as the maincomponents, and containing iron powder by 30 % by weight orless and either or both of Si and Mn in the metallic form by10 % by weight, the submerged arc welding flux having aparticle size distribution arranged such that the proportionof the particle which have a size finer than 36 mesh is 20 %by weight or less and the proportion of the particles whichhave a size 14 mesh or finer but 36 mesh or rougher is 60 %by weight or more; and conducting the welding.