It is usually made of carbon steel or medium manganese […]
It is usually made of carbon steel or medium manganese steel. Its cross section is I-shaped to bear the wheel load of rolling stock and transmit the load to the sleepers. At the same time, it provides a continuous and smooth surface for the rolling of the wheel and guides the wheel to run. Such rail components are called steel rails. On electrified railways and automatic blocking signal lines, steel rails can also double as circuit conductors. The type of rail is usually expressed as the weight per meter of rail. There are 75, 60, 50, 45, and 43 kilograms of steel rail per meter in China.
National rails in British units are available in sizes 132, 112, and 90 pounds. Different types of rails are suitable for different railway lines. They are mainly selected based on the axle weight, speed, and line traffic of rolling stock on the line. For example, light rails can use steel rails with a lower weight per meter, and some light rails. Rails of more than 10 kilograms per meter are used; heavy rails can use heavy rails per meter, and the American Pennsylvania Railroad uses 155 pounds per yard.