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:
Mar. 07, 1989
Filed:
Jul. 09, 1987
Marios Economopoulos, Liege, BE;
Abstract
Starting from a temperature at or above the A.sub.3 transformation point of the steel of the rail, the head of the rail is cooled to a temperature not lower than the Ms point at a rate lower than the critical quenching rate so that the head acquires a fine perlitic structure. Simultaneously the web is superficially cooled to the Ms point or below, at a rate greater than the head, so as to obtain a surface layer of martensite and/or bainite, and the surface cooling is controlled so that, at the end of controlled cooling, internal portions of the web not transformed to martensite and/or bainite retain sufficient heat to temper the surface layer during subsequent cooling to ambient temperature. At the same time the flange of the rail is cooled at a rate ensuring straightness of the rail.