ULTRASONIC FLAW DETECTION METHOD AND APPARATUS

PROBLEM TO BE SOLVED: To provide an ultrasonic flaw detection method and an apparatus, capable of accurately detecting even defects present in the vicinity of the bottom surface of the object material of flaw detection. SOLUTION: The ultrasonic flaw detection apparatus 100 is provided with a wide-band ultrasonic probe 1, arranged in such a way as to make the ultrasonic waves be incident perpendicularly on the surface of the object material of flaw detection; a high-pass filter 2 for cutting off a low-frequency components, by setting a prescribed cut-off frequency that is higher than the lower limit of the frequency band of ultrasonic waves oscillated by the wide-band ultrasonic probe 1 and is lower than its center frequency, from among frequency components of reflected echoes from the object material of flaw detection received by the wide-band ultrasonic probe 1; and a defect detection circuit 3 for detecting defects present in the object material of flaw detection, by comparing the amplitude of output signals of the high-pass filter 2 with a prescribed threshold. COPYRIGHT: (C)2007,JPO&INPIT