Core Differences and Selection Logic Between Chinese National Standard and International Standard Rails
What are the core differences in material selection between national standard and foreign standard rails?
National standard rails mainly use U71Mn and U75V materials, emphasizing a tensile strength of not less than 880MPa, balancing strength and toughness, and adapting to conventional railways and heavy-haul lines. The American AREMA standard mostly adopts 1080/1100 grade high-carbon steel with higher hardness to meet the needs of heavy-haul freight transportation. European EN standard rails focus on fatigue performance, suitable for long-term operation of high-speed railways. Russian GOST standard rails add alloy elements such as chromium and nickel, with excellent low-temperature toughness, capable of resisting extreme low temperatures of -60℃. The selection of different materials is essentially to adapt to the dominant operating scenarios and climatic conditions in respective regions.
What are the differences in dimensional tolerance requirements between national standard and foreign standard rails?
National standard rails have strict control over dimensional tolerances such as rail height and base width. The rail height tolerance of 60kg/m rails is only ±0.5mm, and the base width tolerance is ±0.6mm, ensuring the geometric accuracy of high-speed railway tracks. British standard rails have a rail height tolerance of ±0.7mm and a base width tolerance of ±0.8mm, with relatively loose precision requirements. American AREMA standard rails have slightly larger rail height and base width than national standard rails, capable of withstanding a larger axle load of over 36 tons. European EN standards have strict requirements for the thickness and symmetry tolerances of the rail web to ensure stability during high-speed operation. Differences in dimensional tolerances directly affect track assembly precision and component compatibility.
What are the focuses of national standard and foreign standard rails in environmental adaptability design?
National standard U75V rails undergo special heat treatment to cope with the risk of brittle fracture in areas with large temperature differences such as the Qinghai-Tibet Railway. Russian GOST rails have passed the -60℃ low-temperature impact test, suitable for extremely cold regions like Siberia. The Middle East market prefers European EN standard rails, which add elements such as vanadium and niobium for stronger high-temperature oxidation resistance. American AREMA standard rails focus on wear resistance, adapting to high-frequency friction scenarios of heavy-haul lines. Environmentally adaptive design is key for different standard rails to fit regional climates.
What direct impacts do international certifications have on rail selection?
The European market requires rails to obtain mandatory CE certification, meeting both EN standards and factory production control system requirements. The North American market mostly recognizes AREMA certification to ensure rails comply with local heavy-haul transportation technical specifications. Transnational railway projects often need to meet both UIC and EN standards to pass joint acceptance. Domestic projects prioritize rails complying with GB/T51263-2017 standard to ensure compatibility with domestic supporting components. International certification is a necessary condition for rails to enter the target market, directly determining the selection direction.
How to select national standard or foreign standard rails for different line types?
Domestic high-speed railways prioritize national standard rails such as U71MnG and U75VG, whose dimensional accuracy and welding performance meet the requirements of high-speed operation. Transnational railway projects need to select rail types compatible with the technical standards of the countries passed through. For heavy-haul freight lines located in North America, AREMA standard rails can be selected to adapt to large axle load transportation. Lines in extremely cold regions should choose Russian GOST standard rails to resist low-temperature erosion. Urban light rail lines prefer national standard rails of not less than 50kg/m, and grooved rails can be used for embedded structures.