Nippon Steel Sumitomo Metal Corporation

Keisuke Komatsu

Makoto Sakamoto

Yoshiyuki Nakao

Takashi Fujimoto

Takashi Hibino

Makoto Takata

Shigeki Namekata

In an eddy current testing method which involves using a rotatable eddy current testing probe in which a detection coil is arranged within an exciting coil, a change in detection sensitivity (a deviation of detection sensitivity) which changes depending on the rotational position of the detection coil is reduced. The eddy current testing probe includes an exciting coil EC, a detection coil DC, an exciting coil ECand a detection coil DC, which are mounted on a disk DS. The eddy current testing probe is placed so as to face a circumferential surface of an object to be inspected T, which is in the shape of a circular cylinder, and the disk DS is rotated. Then, the distance (liftoff) between the detection coils DCand DCand an inspection surface changes. Therefore, also the detection sensitivity to a flaw signal changes. To reduce the change in detection sensitivity, the detection sensitivity is adjusted by detecting the rotational position (rotational angle) of the detection coils DCand DC

Eddy current testing method and apparatus for inspecting an object for flaws

A rotary eddy current flaw detection probe device has a plurality of &#x398;-shaped eddy current flaw detection probes attached in a rotating disc for detecting flaws in all directions regardless of the flaw direction. Four &#x398;-shaped eddy current testing probes Pto Pare arranged around the rotation center Dsof a rotating discand are embedded in the disc. The coil planes of detector coils Dsto Dsof the testing probes Pto Pare parallel with each other, and are perpendicular to the rotation plane of the rotating disc. The coil planes of the detector coils incline at an angle &#x3b8; relative to a line Y passing through the centers Psand Psof the probes Pand P. The detector coils Dcand Dcare cumulatively connected to each other and the detector coils Dcand Dcare differentially connected to each other.

Rotary eddy current testing probe device

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Narita, Japan

Keisuke Komatsu