摘要 |
PROBLEM TO BE SOLVED: To provide an inspection method of high accuracy by correcting a scattering attenuation amount in an inspection by an ultrasonic inspection method for a defect which is generated in the jointed part of a metal pipe. SOLUTION: The inspection method is composed of a step in which the crystal particle size of the jointed part of the metal pipe or a thermally affected part near it is found, a step in which ultrasonic waves are made incident from both sides sandwiching the jointed part and which detects reflected waves from the jointed part, a step in which a detected reflection amount from the jointed part is sensitivity-corrected by a correction amount found based on the crystal particle size, and a process in which whether a jointed quality is proper or not is decided based on the sensitivity-corrected correction value. |