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:
Mar. 31, 1998
Filed:
Mar. 25, 1996
Yutaka Kurebayashi, Handa, JP;
Sadayuki Nakamura, Mie-ken, JP;
Masao Goto, Yao, JP;
Atsuhiko Ohta, Kashiwara, JP;
Daido Tokiushuko Kabushiki Kaisha, Osaka, JP;
Koyo Seiko Co., Ltd., Osaka, JP;
Abstract
Bearing steel materials that are superior in cold workability, machinability, hardenability and rolling contact fatigue life are provided. During the processing of steel materials, the generation of large carbides, that detrimentally affect the rolling contact fatigue life of the steel, is inhibited, thereby obviating the necessity of a heat treatment for dissolving the carbides. The present steel material contains the following alloy elements in percentage by mass: 0.55% to 0.82% of carbon; 0.05% to 0.20% of silicon; 0.50% or less of manganese; 0.90% to 1.30% of chromium; 0.05% to 0.30% of molybdenum; and the remaining percentage substantially of iron. After the spheroidizing annealing of the steel material, the total cross-sectional area rate of carbide is 25% or less.