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:
Nov. 12, 2019
Filed:
Aug. 19, 2015
Applicant:
Jfe Steel Corporation, Tokyo, JP;
Inventors:
Assignee:
JFE STEEL CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D 9/00 (2006.01); E01B 5/02 (2006.01); C22C 38/04 (2006.01); C22C 38/02 (2006.01); C21D 9/04 (2006.01); C22C 38/24 (2006.01);
U.S. Cl.
CPC ...
C21D 9/0062 (2013.01); C21D 9/04 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/24 (2013.01); E01B 5/02 (2013.01); C21D 2211/009 (2013.01);
Abstract
A manufacturing method and a manufacturing apparatus for a head hardened rail to which various alloy elements are added and which is excellent in hardness and toughness of a head portion surface layer. The method includes, when forcibly cooling at least a head portion of a hot-rolled rail or a heated rail, starting the forcible cooling from a state where a surface temperature of the head portion of the rail is not less than an austenite range temperature, and performing the forcible cooling at a cooling rate of 10° C./sec or more until the surface temperature reaches 500° C. or more and 700° C. or less after the forcible cooling is started.