公开(公告)号：US10125405B2

公开(公告)日：2018-11-13

申请号：US14407141

申请日：2013-06-07

Applicant: PRIMETALS TECHNOLOGIES ITALY S.R.L.

Inventor： Alberto Gioachino Lainati ,  Luigi Langellotto ,  Andrea Mazzarano ,  Federico Pegorin ,  Alessio Saccocci ,  Augusto Sciuccati

IPC: C21D11/00 ,  C21D1/18 ,  C21D9/04 ,  C21D1/20 ,  C21D1/667

Abstract: A method thermally treats hot rails to obtain a desired microstructure having enhanced mechanical properties. The method includes an active cooling phase where the rail is fast cooled from an austenite temperature and subsequently soft cooled, to maintain a target transformation temperature between defined values. The cooling treatment is performed by a plurality of cooling modules. Each of the cooling modules has a plurality of devices spraying a cooling medium onto the rail. The method is characterized in that during the active cooling phase, each cooling device is driven to control the cooling rate of the rail such that the amount of transformed austenite within the rail is not lower than 50% on the rail surface and not lower than 20% at a rail head core.