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:
Jan. 28, 2020
Filed:
Apr. 06, 2015
Nippon Steel Corporation, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
An object of the present invention is to provide a heat treatment device, a heat treatment method, and a rail steel which are suitable for preventing the occurrence of brittle fractures which originate in a base portion of a weld of the rail steel. A heat treatment device of the present invention includes a coil and heats a bottom surface of the base portion of the weld of the rail steel by induction heating. When a region in the weld which is heated to an Ac1 point or higher during welding is represented by HAZ, and the length of the HAZ in a length direction of the rail on the bottom surface of the base portion is represented by Lh, and a width of the rail steel is represented by W, the length of an outer region of the coil in the length direction of the rail is 1.2 times or more Lh and the length of the outer region of the coil in a width direction of the rail is 1.1 times or more W when viewed from opposite the bottom surface of the base portion.