Rail Core Specifications Compatibility and Material Selection
What are the core specifications of national standard rails and their applicable line scenarios?
National standard rails are mainly divided into four mainstream specifications: 43kg/m, 50kg/m, 60kg/m and 75kg/m, with bearing capacity increasing with rail weight. 43kg/m rails are suitable for factory branch lines and mine light-load tracks, meeting low-speed and small-load driving needs with economical construction cost. 50kg/m rails are the main model for ordinary railway trunk lines, suitable for ordinary railways within 120km/h, balancing bearing capacity and cost performance. 60kg/m rails are suitable for high-speed railway connecting lines and heavy-haul freight lines, bearing 200km/h trains and large-tonnage freight trains. 75kg/m rails are dedicated to high-speed railway main lines and ultra-heavy freight, adapting to 350km/h high-speed railways and 10,000-ton freight trains with optimal wear and impact resistance. All specifications have a standard gauge of 1435mm, which can directly connect with conventional track accessories.
What are the mainstream models of foreign standard rails and corresponding applicable countries/standards?
Foreign standard rails mainly include four models: UIC60, BS80A, AREMA136RE and JIS50N, corresponding to different international standard systems. UIC60 is European standard rail, suitable for railway projects in EU, Middle East, Southeast Asia and other the Belt and Road countries, matching European standard track accessories. BS80A is British standard rail, mainly used for track construction in the UK and Commonwealth countries, with rail base width precisely matching British standard pressure plates. AREMA136RE is American standard rail, suitable for railways in the US, Canada and other North American countries, with tensile strength adapting to North American heavy-haul freight needs. JIS50N is Japanese standard rail, used for Japanese and some Southeast Asian Japanese-style track projects with high dimensional accuracy requirements. Foreign standard rails are produced according to corresponding national standards, and materials and accessories must be matched with the same standard.
What are the core material differences and performance indicators of national and foreign standard rails?
The main materials of national standard rails are U71Mn and U75V high-strength alloy rails, U71Mn has good plasticity for ordinary railways, and U75V has wear resistance and fatigue resistance for high-speed/heavy-haul railways. U71Mn rail has tensile strength ≥880MPa and yield strength ≥785MPa, meeting the impact resistance requirements of ordinary railway driving. U75V rail has tensile strength ≥980MPa and wear resistance increased by 30%, which can reduce the grinding frequency of high-speed railway tracks and extend the service cycle. Foreign standard rail materials include UIC900A, Grade335, etc., UIC900A has tensile strength ≥900MPa, adapting to European standard high-load lines. Foreign standard materials all meet the mechanical requirements of corresponding international standards, and the alloy ratio is more suitable for local climate and load characteristics compared with national standard materials.
What are the core factors and matching principles for rail selection?
The primary factor for rail selection is line driving speed and freight tonnage, high-speed/heavy-haul lines prefer large-specification and high-material rails, and light-load lines select small-specification economical rails. Secondly, it is necessary to match the track accessory system, national standard rails with national standard fastening systems/fishplates, foreign standard rails with the same standard foreign standard accessories, avoiding mixing leading to 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. The selection must follow the principles of load matching, standard unification and environment adaptation, and refer to the line design life to reduce later replacement costs. In addition, cross-border projects need to be selected according to the standards of the project host country to ensure compliance with local track construction specifications.
What are the core specifications and protection points for rail transportation and storage?
Special rail transport vehicles must be used for rail transportation, both ends of the rail 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. The number of stacked rails shall not exceed 6 layers for long-distance transportation, and anti-slip pads shall be added between layers to prevent rail deformation during transportation affecting accuracy. Rails shall be stored on flat hardened sites, stored overhead at least 15cm above the ground to avoid corrosion of the rail bottom 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 rail surface accuracy. If the storage period exceeds 3 months, the corrosion shall be checked regularly, anti-rust oil shall be replenished in time, and rust on the rail surface shall be polished before use to ensure track laying accuracy and use safety.