The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 01, 2005
Filed:
Sep. 05, 2001
Keisuke Fujisaki, Futtsu, JP;
Kazuomi Tomita, Muroran, JP;
Keisuke Fujisaki, Futtsu, JP;
Kazuomi Tomita, Muroran, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
A flaw detection device for a steel bar enabling inspection of a high temperature steel bar at a high temperature. A pre-treatment unit, detection unit, and post-treatment unitare arranged along a running direction of a steel bar. The pre-treatment unit and post-treatment unit have the same structure. Direct current coilsandare wound around the outside of the sleevesand. The steel bar is magnetically saturated by the direct current magnetic field. An eddy current is generated at the surface of the steel bar by an alternating current coilof a detection unit. The change in the magnetic field caused by the eddy current is detected by the detection windingsand. The sleeves are made of nonmagnetic materials, so the strength of the direct current magnetic field becomes flat along the running axis of the steel bar. Even when moving the steel bar at a high speed, the occurrence of noise due to changes in strength of the direct current magnetic field is suppressed.