| 摘要 |
PURPOSE:To accurately detect the presence and size of a defect while holding detecting sensitivity of the defect high by providing an ultrasonic probe for a transmission on the opposite side of a wheel to be detected for the flaw of an ultrasonic probe for reception. CONSTITUTION:An ultrasonic probe 27 is so set at a predetermined tilting angle radially of a wheel 3 as to receive ultrasonic wave in an oblique direction to a defect 8 in the axial direction generated in a blade implanted part 5, and the other ultrasonic probe 27' is so set at a predetermined tilting angle to the radial direction of the wheel 3 as to receive its reflected ultrasonic wave. In order to detect the flaw of the part 5, the probes 27, 27' are sequentially operated in the circumferential direction while bringing them into close contact with one another whole holding a predetermined tilting angle and probe positions at the surface of the wheel 3 by a probe holding mechanism. Simultaneously, an ultrasonic beam gamma is made incident from the one probe 27 on the wheel 3. If a defect 8 in the axial direction exists at the part 5, the transmitted ultrasonic beam gamma is reflected by the defect 8 to generate a reflected ultrasonic beam beta, and the probe 27' detects a defect echo. |
