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:
Jul. 27, 2010
Filed:
Apr. 14, 2004
Takashi Iwamoto, Kurashiki, JP;
Akihiro Matsuzaki, Kurashiki, JP;
Kazuhiko Ohno, Kurashiki, JP;
Masao Goto, Habikino, JP;
Hisashi Harada, Kashiwara, JP;
Hisato Nishisaka, Kashiwara, JP;
Takashi Iwamoto, Kurashiki, JP;
Akihiro Matsuzaki, Kurashiki, JP;
Kazuhiko Ohno, Kurashiki, JP;
Masao Goto, Habikino, JP;
Hisashi Harada, Kashiwara, JP;
Hisato Nishisaka, Kashiwara, JP;
JFE Steel Corporation, Tokyo, JP;
Koyo Seiko Co., Ltd., Osaka-Shi, JP;
Abstract
Provided are a steel having excellent rolling contact fatigue life and the manufacturing method thereof. The steel consists essentially of 0.7 to 1.1% C, 0.2 to 2.0% Si, 0.4 to 2.5% Mn, 1.6 to 4.0% Cr, 0.1% or more and less than 0.5% Mo, 0.010 to 0.050% Al, bymass, and balance of Fe and inevitable impurities, is treated by quenching and tempering, has residual cementite grain sizes ranging from 0.05 to 1.5 μm, and has prior-austenite grain sizes of 30 μm or smaller. When the steel is used to bearing steel, the bearing life extends even under service in more severe environments.