Defect detection method and scanning-type defect detector of metal body

摘要

PROBLEM TO BE SOLVED: To detect flaws of a magnetic metal body in a fully accurate manner, moreover, with proper workability, using a magnetic impedance effect type sensor by a leaking magnetic flux flaw detection test method.;SOLUTION: The surface of the metal body is scanned, by using a demagnetization/magnetization means for demagnetizing or magnetizing the metal body so as to uniformize the magnetized state of the metal body, a magnetization means for generating a leak magnetic flux at the flaw location of the metal body and a flaw detector, having a magnetic impedance effect type sensor for detecting the leaking magnetic flux at the flaw location of the metal body. During this scanning, the leaking magnetic flux is produced at the flaw location of the metal body in the magnetic field of the magnetize means by tracing the mark, wherein the demagnetization or magnetization is performed by the demagnetization/magnetization means and detected by the magnetic impedance effect type sensor.;COPYRIGHT: (C)2007,JPO&INPIT