ULTRASONIC FLAW DETECTION DEVICE, ULTRASONIC FLAW DETECTION METHOD, AND ULTRASONIC FLAW DETECTION PROGRAM

摘要

The purpose of this invention is to enhance the reliability of inspection in ultrasonic flaw detection using a phased-array ultrasonic-flaw-detection probe. A flaw detection probe is placed such that the center of curvature of the flaw detection probe coincides with a reference center of curvature that is the center of curvature of the curve of the outline of a cross section of a subject at a reference scan position of the subject. Next, while this orientation is maintained, the flaw detection probe is translated along a scan direction. At a given scan position, the flaw detection probe emits an ultrasonic beam such that the position upon which the ultrasonic beam converges coincides with the center of curvature of the curve of the outline of the cross section of the subject at the scan position, receives the resulting reflected beam, and estimates the length of a flaw in the circumferential direction of the subject on the basis of the reflected beam. In addition, the estimated length of the flaw is corrected using a correction coefficient corresponding to the distance between the center of curvature of the reference scan position and the center of curvature of the scan position in the thickness direction of the subject.