Use and replacement of rails

Why should the rails be laid with rustable steel? Many people have a misunderstanding about steel rails. Steel rails are actually just short for railway tracks. Its raw materials are not pure iron but made of high-hardness and high-toughness steel. In order to improve the degree of compression and wear resistance, more than 13% manganese and a certain amount of carbon are added to the rail during smelting, and another metal indium is added to the surface layer in contact with the wheel. It is able to maintain hardness while being tough.

Steel smelting When the steel rails are laid on the road surface and cooperate with the sleepers below, they can continue to withstand the repeated pressure of the train. Even if the wind and rain are exposed to the sun, only the surface will rust, and the internal structure will still be intact. To ensure the safe operation of the train.

Why don’t rusted rails use stainless steel? In contrast to stainless steel, it is not easy to rust, but its thermal expansion coefficient is relatively large, and its resistance is not enough. Whether it is high cold or hot weather, or the extrusion of wheels, it is easy to deform stainless steel, which undoubtedly will bring a great threat to the safety of train operation, and naturally, it is not suitable for making steel rails. Since the performance of manganese steel is so superior, how many years can the rails make of it last?

The life of the rail mainly depends on the wear of the wheel and rail. In general, after the rail is worn, it is only necessary to use a rail grinding car or a grinding tool to grind the section normally. Of course, the rail cannot be unrestricted. When the critical point is reached, it can only be scrapped. The annual gross weight of the line is different, and the loss of the rails will also be different. For heavy-duty lines like the Daqin Railway, as a major channel for my country’s west-to-east coal transportation, its annual transportation volume can reach 400 million tons. The lifespan will definitely be greatly reduced under the rolling, and generally, it will be scrapped in less than a year.

The service life of rails on the Daqin Railway and ordinary railways is about ten years. For example, the Wuhan Yangtze River Bridge is completely replaced every seven or eight years on average. Since it was opened to traffic on October 15, 1957, the rails have been replaced eight times so far. The latest comprehensive replacement was on June 13, 2018. How to deal with scrap rails? Some steel rails with less damage can be installed on low-standard railways to continue to exert waste heat, or they can be sold to companies that need to lay tracks in roadways. For example, in the installation of gantry cranes and cranes, compared with new rails, these enterprises can not only save a lot of costs but also achieve the same effect when used.

For gantry cranes, those non-reusable steel rails can be sold to large heavy industry companies for use as dunnage. Compared with wood, steel rails are not only strong but also have a certain weight, and the goods will not fall like logs after being put on them. In the end, it is used as heavy scrap steel to regenerate resources and then process it into useful steel.