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.

Date of Patent:
Nov. 27, 2012

Filed:

May. 22, 2009
Applicants:

Takafumi Murakami, Tochigi-ken, JP;

Naoto Shibata, Utsunomiya, JP;

Shunta Osako, Utsunomiya, JP;

Inventors:

Takafumi Murakami, Tochigi-ken, JP;

Naoto Shibata, Utsunomiya, JP;

Shunta Osako, Utsunomiya, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C22C 38/36 (2006.01); C21D 9/36 (2006.01);
U.S. Cl.
CPC ...
Abstract

Disclosed is a ball for a constant velocity joint, and a method for producing the same. The ball for a constant velocity joint is produced via a quenching step for heating a spherical body consisting of a material corresponding to a high carbon chromium bearing steel regulated by Japanese Industrial Standards (JIS) to 840-900° C. and then cooling the spherical body under such a condition as 10-25 vol. % of austenite remains up to a first part where the depth from the surface is 0.1 mm, a step for tempering the spherical body at 150° C. or more, and a step for shot peening the spherical body and imparting a compression residual stress of −1000 MPa or more to a region reaching second part where the depth from the surface is 0.2 mm.


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