| 摘要 |
<p>Provided are a method and a device for detecting the defects of a welded-portion, which can detect the defects of not only the surface but also the inside or deep portion of the welded portion and the defects of a mother material near the welded portion, without subjecting the welded portion to a pretreatment. The defects of the welded portion are detected by applying an AC magnetic field from an exciting coil to the welded portion to be detected on its defects, by generating an induced electromotive force in an induction coil by an AC magnetic field to pass through that welded portion, and by determining the variation of at least one of the amplitude and phase of the induced electromotive force generated in the induction coil, with respect to at least one of the amplitude and phase of a reference induced electromotive force.</p> |
