| 摘要 |
PURPOSE:To detect the position of the end of a crack and the depth thereof by a method wherein scanning is performed by deflecting, in the direction of the crack, ultrasonic beams delivered from probes for transmission and reception, and detection points are averaged by altering the relative distance of the probes. CONSTITUTION:An array-type probe 1A for transmission and an array-type probe 1B for reception are arranged so that they hold the position of a crack 10a of a body 10 to be inspected between, and scanning is performed by deflecting ultrasonic beams (a) and (b) from these probes in the direction of the crack. Thereby a point whereat a scattering echo from the end of the crack is generated is detected, and thus the position of the end of the crack 10a is detected. In addition, the relative distance between the two probes 1A and 1B is altered by selecting groups of ultrasonic vibrators, the position of the end of the crack 10a is detected every time when the relative distance is altered, detection points are averaged, and thereby the depth of the crack from the surface is detected. Accordingly, the depth of the crack can be estimated by operation under the condition of highly sensitive flaw detection, and thus the precision of the flaw detection can be improved sharply. |
