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:
Dec. 12, 1989
Filed:
May. 20, 1988
Toyokazu Teramoto, Tokyo, JP;
Akio Fujibayashi, Tokyo, JP;
Kozo Fukuda, Tokyo, JP;
Mashiro Ueda, Tokyo, JP;
Shinichi Nagahashi, Tokyo, JP;
Yazuru Kataoka, Tokyo, JP;
Hiroaki Sato, Tokyo, JP;
Tsunemi Wada, Tokyo, JP;
Takao Gino, Tokyo, JP;
Yoshio Saito, Tokyo, JP;
Kiyotaka Morioka, Tokyo, JP;
NKK Corporation, Tokyo, JP;
Abstract
A method for heat-treating a steel rail head, which comprises: heating a steel rail head to the austenization temperature; then, cooling the rail head by means of a hot water jet until a surface temperature of the rail head decreases to a temperature not below 420.degree. C.; and then cooling the rail head by means of an air jet at least to the pearlite transformation temperature, thereby transforming the structure of a surface portion of the rail head into a uniform and fine pearlite structure. The above-described method includes a method in which the rail head is previously cooled by means of a water spray until the surface temperature of the rail head decreases to a temperature not below 530.degree. C. prior to the cooling of the rail head by means of the above-mentioned hot water jet.