| 摘要 |
PROBLEM TO BE SOLVED: To provide a repair method of a steel pipe capable of properly detecting a welding defect after welding.SOLUTION: In a repair method of a steel pipe 5 for repairing a damaged part caused on a surface of the steel pipe 5, the repair method of the steel pipe comprises a welding process of fillet-welding a part between a sleeve pipe 3 or a patch and the steel pipe 5, by arranging the sleeve pipe 3 or the patch for in which an inverse groove 1 is formed in the steel pipe 5 so as to cover the damaged part and an inspection process of executing a nondestructive inspection on a welding part formed by the welding process by ultrasonic flaw detection, in which a groove angle θ of the inverse groove 1 is set to an angle for satisfying y≤2 t/tanθ, when assuming a plate thickness of the sleeve pipe 3 or the patch as (t) and a diameter of a probe 9 used for the ultrasonic flaw detection as (y), a weld-penetration inspection of a root part is executed by a vertical flaw detection method by inspecting the welding part in the inspection process by combinedly using an oblique angle flaw detection method and the vertical flaw detection method.SELECTED DRAWING: Figure 1 |
