| 摘要 |
PROBLEM TO BE SOLVED: To obtain an eddy current flaw detection method capable of expanding a phase difference between a flaw signal and a vibration noise even in the case of application to a non-magnetic material or a magnetic material heated to a temperature above its Curie point, to enhance the improving effect of an S/N ratio by phase detection. SOLUTION: In this eddy current flaw detection method, an eddy current is induced in a specimen 16 by flowing an alternating current through a solenoid- like test coil 10 with passing the specimen 16 made of a non-magnetic material or a magnetic material heated to a temperature above its Curie point through the test coil 10, and a change of the eddy current is detected. The frequency of the alternating current flowing through the test coil 10 is controlled to 200-1,000 kHz, preferably, 300-600 kHz.
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