The selection of railway track materials is mainly based on the following criteria:
1、 Strength requirements
1. Bear the weight of the train
-The weight of trains is very large, especially heavy-duty trains. For example, a heavy-duty freight train may weigh tens of thousands of tons. The track must have sufficient strength to support the weight of the train and prevent deformation or breakage of the track when the train passes through. High strength steel, such as high manganese steel or alloy steel with added alloying elements (such as chromium, molybdenum, etc.), can meet this requirement. These steels have high yield strength and tensile strength, and can withstand tremendous pressure without deformation.
2. Resist dynamic loads
-During the operation of a train, the wheels apply dynamic loads to the track. This dynamic load will cause vibration and fatigue stress in the track. The material needs to have good fatigue resistance to ensure that cracks or fractures will not occur under long-term dynamic loads. For example, alloy steel tracks that have undergone special treatment have a uniform internal structure and can effectively resist the accumulation of fatigue stress.
2、 Wear resistance requirements
1. Reduce maintenance costs
-The friction between train wheels and tracks can cause wear on the surface of the tracks. If the wear resistance of the track is poor, frequent maintenance or replacement is required, which will increase operating costs. High manganese steel tracks, due to their surface hardening under pressure, have excellent wear resistance and can greatly reduce the frequency of maintenance and replacement.
2. Adapt to different traffic volumes
-For railway lines with large capacity, such as busy mainline railways or heavy-duty railways, the wear and tear of the tracks will be faster. Therefore, materials with higher wear resistance, such as steel containing special alloy elements, are usually chosen on these lines to ensure that the service life of the track can meet operational needs.
3、 Resilience requirements
1. Coping with impact loads
-When a train starts, brakes, or passes through a switch, it will generate impact loads on the track. The track material needs to have sufficient toughness to absorb these impact energies and prevent the track from suddenly breaking. For example, in mountainous railways, due to frequent undulations and bends encountered during train operation, the track needs to have good resilience to cope with the impact generated by train acceleration and deceleration.
2. Adapt to complex environments
-In some earthquake prone areas or areas with complex geological conditions, the track may be subjected to additional stress. Resilient track materials can adapt to these complex environmental conditions to a certain extent, reducing the risk of track damage.
4、 Corrosion resistance requirements
1. Special environmental requirements
-Railway tracks near the seaside or chemical enterprises are prone to corrosion from seawater, chemicals, and other substances. Choosing materials with corrosion resistance, such as alloy steel with added alloying elements such as chromium and nickel, can effectively resist corrosion and extend the service life of the track.
2. Reduce maintenance difficulty
-A track material with good corrosion resistance can reduce track damage caused by corrosion, reduce the difficulty and workload of maintenance personnel in anti-corrosion treatment of the track, and improve the efficiency of railway operation.
