METHOD FOR IMPROVING FATIGUE STRENGTH AT WELDING JOINT OF STEEL FOR STRUCTURE

摘要

PROBLEM TO BE SOLVED: To improve joint fatigue strength under a condition that a normal welding operation is applied to a normal steel for structure including a high tensile steel by applying arc welding on a steel plate after an oxide film except for iron is adhered on the steel plate surface. ;SOLUTION: In this method for improving fatigue strength of a welding joint of a steel for structure, it is preferable that an oxide film is composed of an alumina base oxide film or a silica base oxide, and the oxide is coated on the steel plate surface by thermal spraying. Due to a stable oxide film of Al2O3 or SiO2 existing on the surface of the steel plate to be welded, penetration depth is small and bead width is wide when welding is performed. Thereby, a toe shape of the welding joint is smooth and joint fatigue strength is significantly improved. A toe angle 11 is a jointing angle of a welding bead 10 and a welded steel plate surface. The bigger the angle becomes, the smoother the welding bead 10 gets. In the case of the welding joint requiring multi-pass welding, at a final pass for forming the welding toe part, similar effects can be expected by applying the oxide and the like.;COPYRIGHT: (C)2000,JPO