| 摘要 |
PROBLEM TO BE SOLVED: To prevent over-detection of a primary crack to reduce a noise level from crystal grain boundaries, and to improve flaw detecting performance, at the time of ultrasonic flaw detection using a surface wave. SOLUTION: At the time of ultrasonic flaw detection using a surface wave to a hot rolling roll, a surface wave probe 10, which transmits and receives the surface wave, is provided with a resin wedge 10C on an ultrasonic wave transmission/reception face of its ultrasonic vibrator 10A, and a damping material 10B on a rear face of the ultrasonic vibrator 10A, while a short pulse whose width is not more than 2.5 times a wave length of the surface wave is generated and transmitted from the surface wave probe 10. Further, a liquid medium is supplied according to a periphery speed of the roll. The roll is ground by a grinding amount which is decided according to a height of a reflected wave, while the roll is flaw-detected with the partial grinding so that an optimum value of the roll grinding amount is decided. |
