Material Differences and Compatible Applications of Chinese Standard Rails and Foreign Standard Rails
What are the core chemical differences between Chinese standard (GB) and international standard (IAS) steel rails?
GB rails (such as U71Mn and U75V) use manganese as the main alloying element, with stricter control over sulfur and phosphorus content. European standard rails emphasize low carbon and high purity, while American standard rails adjust chromium and vanadium content according to strength grade. These differences in alloy ratios directly determine the wear resistance and fatigue resistance of the rails, adapting them to different operating environments.
What are the differences in their mechanical properties?
GB rails have a tensile strength concentrated between 880-1100 MPa, and their yield strength meets the requirements of heavy-load and high-speed railways. European standard rails are graded according to EN standards, with a wider strength range. American standard rails have differentiated hardness and impact toughness indicators for different rail types. These differences allow them to adapt to domestic and international standardized railway engineering projects, respectively.
What are the main differences in the dimensional specifications between GB and IS steel rails?
National standard rails primarily use 60kg/m and 50kg/m gauges, with fixed lengths of 25m/100m. Foreign standard rails, however, come in various gauges such as 30kg/m and 115RE, with significant deviations in length, rail head profile, and rail base width compared to national standards. Specialized fasteners are required during construction; otherwise, the stability of the track structure will be affected.
How should national or foreign standard rails be selected for domestic railway lines?
Domestic conventional, high-speed, and heavy-haul trunk lines must use national standard rails to comply with railway operation safety regulations. Only in international projects and overseas aid projects are corresponding foreign standard rails selected according to the owner's standards, and a customized fastener system must be used to avoid defects caused by specification mismatch.
What impact do differences in rail material have on the matching fastening system?
National standard rails have higher hardness and require high-strength elastic clips and bolts to provide sufficient clamping force; foreign standard rails have special contours and cannot be matched with conventional fastening systems. Custom-made pressure plates, rail spikes and other components are required. Improper matching can lead to rail displacement and loose fasteners, threatening traffic safety.