1. Different rail types and operating conditions around the world

1.1 Description

The rail is a rolled product of pearlitic steel (carbon content between 0.5 and 0.85%) with HB (Brinell hardness) hardness ranging from 200 to 440, with or without the addition of alloying elements and with or without heat treatment, having a rolled structure with an index grain of 7 to 9, corresponding to an average grain diameter of between 18 and 36 μm.

Geometrically, it consists of a massive "mushroom" tread at the top, up to 75 mm wide, with a transverse radius of 300 mm on the central major part, completed by two symmetrical radii of 80 mm and then 13 mm in connection with the vertical walls (figure 1 ). This quasi-horizontal surface supports all rail-wheel contact...