| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic flaw detection method capable of simply and accurately detecting a flaw existing on the surface of an object to be inspected of the inspection material by arranging a sensor coil to face a surface opposite to the inspection object surface.SOLUTION: A magnetic flaw detection method according to the present invention supplies an AC current to a sensor coil 3 by arranging the sensor coil 3 so as to face a surface S1 opposite to an inspection object surface S2 of an inspection material S, and the inspection material S is magnetized by direct current magnetization means 1 by arranging the direct current magnetizing means 1 such that the magnetic flux density of the surface S1 side (region A1) opposite to the inspection material S is less than the saturation magnetic flux density and becomes smaller than the magnetic flux density of the inspection object surface S2 side (region A2) in the inspection material S, and a flaw D existing on the inspection object surface S2 is detected based on the impedance change of the sensor coil 3.SELECTED DRAWING: Figure 2 |
