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:
Apr. 23, 2002
Filed:
May. 17, 2000
Applicant:
Inventors:
Hiroyasu Yokoyama, Fukuyama, JP;
Shinji Mitao, Fukuyama, JP;
Assignee:
NKK Corporation, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
C22C 3/812 ; C22C 3/826 ; C22C 3/848 ;
U.S. Cl.
CPC ...
C22C 3/812 ; C22C 3/826 ; C22C 3/848 ;
Abstract
A pearlitic steel railroad rail which comprises 0.75 to 0.84% C, 0.10 to 1.0% Si, 0.4 to 2.5% Mn, 0.035% or less P, 0.035% or less S, and 0.05 to 0.6% Nb, by weight. This rail has better wear resistance than the heretofore used pearlitic steel rail and sufficient ductility so cracks do not appear due to thermal dilation and contraction caused by a change of temperature. The rail is consequently very suitable for the use in a mine railroad.