抄録
In this paper, the performance of surface flaw detection by Magnetic Flux Testing (MFLT) using a Magneto-Impedance (MI) sensor is described. The MI sensor was used to measure the Magnetic Flux Leakage (MFL) that occurs near to flaws when the inspected material is magnetized. In order to develop a compact and handy MFL probe, a small-sized magnetic yoke was made and integrated with the MI sensor. Flat plate specimens of SS400 with artificial flaws or a fatigue crack on the surface were prepared and evaluated, first, for the relationship between artificial flaw depths and flaw signal amplitude. Secondly, the detection of the fatigue crack was attempted. The results show that the developed MFL probe can evaluate the artificial flaw depths quantitatively and detect the fatigue crack clearly. Furthermore, the developed MFL probe can measure flaws with a low excitation current, unlike a conventional MFLT. Accordingly, it is expected that a portable non-destructive inspection system with the developed MFL probe will be developed in the future.
