ULTRASONIC FLAW DETECTION AND INSTRUMENT THEREFOR

摘要

PURPOSE:To enable a defect produced in the circumferential direction of an object to be inspected by emitting ultrasonic waves deflected in a direction intersecting an emitting plane onto the object to be inspected and measuring reflected waves therefrom. CONSTITUTION:Ultrasonic waves emitted from an array type probe wherein a plurality of ultrasonic oscillators 11n(n=1-100) are arranged on the same circle are perpendicularly incident on an acoustic lens 14 via a position P1. The ultrasonic waves are deflected in a direction intersecting an emitting plane formed by the probe 12 to be emitted from a position P2 and incident on an object to be inspected, for example, a tubular material 6 via a position P3. The incident ultrasonic waves proceed in a direction shown by an arrow D and are reflected from a defect 6a produced on the tubular material 6 in its circumferential direction. By the method described above, the defect 6a in the circumferential direction of the tubular material 6 can be detected and the reliability of ultrasonic wave flaw detection is improved.