National Standard/International Standard Rail Core Specifications Selection and Material Compatibility Technology
What are the core applicable scenarios of each national standard rail specification?
National standard 43kg/m rails are suitable for factory branch lines and mine light-load tracks, meeting low-speed and small-tonnage driving needs with economical construction cost and easy maintenance. 50kg/m rails are the main force of ordinary railway trunks, suitable for ordinary railways within 120km/h, balancing bearing capacity and cost performance, and widely used in national ordinary railway lines. 60kg/m rails are suitable for high-speed railway connecting lines and heavy-haul freight lines, bearing 200km/h trains, with better wear and impact resistance than 50kg/m models. 75kg/m rails are dedicated to high-speed railway main lines and 10,000-ton freight, suitable for 350km/h high-speed railways, with the best tensile strength and wear resistance, being the core selection for high-grade lines. All specifications adopt 1435mm standard gauge, which can directly match national standard track accessories without additional gauge adjustment.
What are the mainstream models of foreign standard rails and corresponding engineering standards?
Foreign standard UIC60 rails are the core European standard model, suitable for cross-border railways of the Belt and Road in the EU, Middle East and Southeast Asia, and need to match European standard fastening systems and pressure plates. BS80A rails are special British standard models, mainly used for track projects in the UK and Commonwealth countries, with rail base size matching British standard fishplates and bolts. AREMA136RE rails are the main American standard model, suitable for North American heavy-haul freight lines in the US and Canada, with tensile strength meeting the needs of large-tonnage freight. JIS50N rails are Japanese standard models, used for Japanese and Southeast Asian Japanese-style track projects, with high dimensional accuracy requirements and the need to match Japanese standard accessories. Foreign standard rails are produced in strict accordance with corresponding international standards, with materials and dimensions strictly benchmarked, and cross-border projects need to be selected according to the host country's standards.
What are the performance differences between the two core materials of national standard rails?
National standard U71Mn rails are special materials for ordinary railways, with good plasticity and excellent welding performance, tensile strength ≥880MPa, yield strength ≥785MPa, meeting the impact needs of ordinary railway driving. U75V rails are special materials for high-speed railways/heavy haul, adding vanadium to improve wear resistance and fatigue resistance, tensile strength ≥980MPa, and wear resistance 30% higher than U71Mn. U71Mn rails have lower production cost, suitable for light-load and low-speed lines, with slightly higher later maintenance frequency than U75V models. U75V rails have strong rail head wear resistance, reducing track grinding frequency, and are mandatory for high-speed railway main lines and heavy-haul freight lines. Both materials comply with the national standard GB/T 2585-2018, and can be flexibly selected according to line grades.
What are the three core factors for key consideration in rail selection?
The primary factor for rail selection is driving speed and freight tonnage, high-speed/heavy-haul lines must select large-specification and high-material rails to avoid overload deformation. Secondly, it is necessary to match the accessory system, national standard rails with national standard fastening systems and fishplates, foreign standard rails with the same standard foreign standard accessories, and mixed matching will lead to excessive installation gaps. It is also necessary to combine the use environment, anti-corrosion rails for coastal humid areas, wear-resistant rails for mine dusty areas, and low-temperature resistant rails for severe cold areas. At the same time, refer to the line design life, high-grade lines prefer 75kg/m U75V rails to extend the overall service cycle of the track. Selection also needs to check rail straightness and surface finish to ensure no factory defects such as cracks and rust.
What are the core protection points for rail transportation and storage?
Special rail transport vehicles must be used for rail transportation, both ends are fixed to prevent sliding, and the rail surface is covered with a protective film to avoid collision and scratch on the rail head working surface, affecting driving smoothness. For long-distance transportation, the number of stacked rails shall not exceed 6 layers, and anti-slip pads shall be added between layers to prevent rail bending deformation during transportation and ensure installation accuracy. Rails shall be stored on flat hardened sites, stored overhead at least 15cm above the ground to avoid corrosion of the rail bottom and waist by ground moisture. The storage area shall be well rainproof and drained, anti-rust oil shall be brushed on the rail surface, and foreign standard rails shall be additionally covered with protective sleeves to protect dimensional accuracy. If stored for more than 3 months, regularly check the corrosion, replenish anti-rust oil in time, and polish rust on the rail surface before use to ensure laying quality.