ANGLE BEAM FLAW DETECTING METHOD FOR HOLLOWED AXLE

PURPOSE:To surely separate a defect echo from a press-fit echo in a part easy to generate the press-fit echo in a fitting part between wheels such as a wheel seat at the time of detecting the flow of an axle by spiral scanning. CONSTITUTION:A flaw detecting method for hollowed axle comprises detecting the flaw of a hollowed axle 100 from the inner part by spirally scanning ultrasonic probes 1a, 1b in the hollowed part inner part 103 of the axle 100. In the flaw detection of a fitting part 102 in a wheel 101, the presence of continuity of the flaw detecting echo in the axle 100 circumferential direction is detected near this side of a flaw detecting gate in the longitudinal direction of the axle 100, and the presence of a harmful defect is judged.