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:
Aug. 14, 2018
Filed:
Jan. 22, 2016
Applicant:
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Inventors:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D 9/04 (2006.01); E01B 5/02 (2006.01); C22C 38/00 (2006.01); C22C 38/04 (2006.01); C22C 38/58 (2006.01); C22C 38/10 (2006.01); C21D 8/00 (2006.01);
U.S. Cl.
CPC ...
C21D 9/04 (2013.01); C22C 38/00 (2013.01); C22C 38/04 (2013.01); C22C 38/105 (2013.01); C22C 38/58 (2013.01); E01B 5/02 (2013.01); C21D 8/00 (2013.01); C21D 2211/009 (2013.01);
Abstract
The present invention relates to a rail which has a predetermined chemical composition and in which at least 90% of a metallographic structure from an outer surface of the rail bottom portion, as the origin, to a depth of 5 mm is a pearlite structure, a surface hardness HC of a foot-bottom central portion is in a range of Hv 360 to 500, a surface hardness HE of a foot-edge portion is in a range of Hv 260 to 315, and HC, HE, and a surface hardness HM of a middle portion positioned between the foot-bottom central portion and the foot-edge portion satisfy HC≥HM≥HE.