Metal tube defect inspection method, metal tube manufacturing method, metal pipe defect inspection apparatus and metal pipe defect inspection program

摘要

PROBLEM TO BE SOLVED: To provide a defect inspection device of a metal pipe and a defect inspection method of a metal pipe which can suppress erroneous recognition of a defect of a metal pipe.SOLUTION: A defect inspection method of a metal pipe comprises: an arrangement process for arranging a transmission part which transmits an ultrasonic wave to a metal pipe at a transmission position separated by a prescribed distance from the outer periphery of the metal pipe and having a prescribed transmission angle with respect to the radial direction of the metal pipe, and arranging a reception part which receives the ultrasonic wave transmitted from the transmission part and propagated in the metal pipe to convert it into an ultrasonic signal at a reception position separated by a prescribed distance from the outer periphery of the metal pipe and having a prescribed reception angle with respect to the radial direction of the metal pipe; and a flaw detection process for detecting a defect of the metal pipe on the basis of change in the amplitude of the ultrasonic signal by transmitting the ultrasonic wave to the metal pipe delivered in the axial direction with the transmission part and by receiving the ultrasonic wave propagated in the metal pipe to convert it into the ultrasonic signal with the reception part. In the flaw detection process, the transmission part and the reception part are made to follow the metal pipe delivered in the axial direction respectively at the transmission position and the reception position.