EP 0252895 B1 19921021 - METHOD AND APPARATUS FOR PRODUCING HIGH RESISTANT RAILS
Title (en)
METHOD AND APPARATUS FOR PRODUCING HIGH RESISTANT RAILS
Publication
Application
Priority
LU 86510 A 19860710
Abstract (en)
[origin: US4810311A] Starting from a temperature at or above the A3 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.
IPC 1-7
IPC 8 full level
CPC (source: EP US)
Citation (examination)
PATENT ABSTRACTS OF JAPAN vol. 11, no. 315 (C-451)(2762) 14 octobre 1987; & JP-A-6299438 NIPPON KOKAN) 08.05.1987; & US-A-47 67475
Designated contracting state (EPC)
AT BE DE ES FR GB IT
DOCDB simple family (publication)
EP 0252895 A2 19880113; EP 0252895 A3 19900718; EP 0252895 B1 19921021; AT E81676 T1 19921115; CA 1307723 C 19920922; DE 3782280 D1 19921126; JP 2716127 B2 19980218; JP S6328824 A 19880206; LU 86510 A1 19880202; US 4810311 A 19890307
DOCDB simple family (application)
EP 87870094 A 19870707; AT 87870094 T 19870707; CA 541732 A 19870709; DE 3782280 T 19870707; JP 17271387 A 19870710; LU 86510 A 19860710; US 7168987 A 19870709