| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic flaw detection method and an ultrasonic flaw detection device capable of improving flaw detection sensitivity, and performing highly accurate flaw detection inspection. SOLUTION: A curved-surface vibrator 23 is set so that acoustic distances between each point on the output face of the curved-surface vibrator 23 and a convergent point (flaw 12X) of an ultrasonic beam on the surface of an axle 12 agree with each other. Namely, mesh M is cut on the inner face of the axle 12, and straight lines combining each point on the mesh M with the flaw 12X are assumed, and ultrasonic routes and propagation times to the curved-surface vibrator 23 are calculated from the straight lines, and the curved-surface shape of the output face of the curved-surface vibrator 23 is determined. Then, a propagation route until the ultrasonic beam is reflected by the flaw 12X is assumed, and the final curved-surface shape is calculated by correcting the shape of the vibrator so that the phases totally agree on the whole surface of the vibrator from the amplitude change following diffusion, and the difference of the amplitude change/phase change at the refraction time. An ultrasonic energy density can be heightened and the flaw detection sensitivity can be improved by using the curved-surface vibrator 23. COPYRIGHT: (C)2003,JPO
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