The 75kg heavy rails adopt an I-shaped cross-section design, which consists of three parts: the rail head, the rail waist, and the rail bottom to form a rigid whole. The size and shape of each part are optimized for heavy-load scenarios to ensure force transmission efficiency and structural stability.
The rail head is the core area of the bearing wheel-rail contact, and adopts a "hat-shaped" design with arc transition. The top width is 73mm, which is 8mm wider than the 60kg heavy rail, increasing the contact area with the wheel tread and reducing the pressure per unit area. There is a 1:4 slope on both sides of the rail head to form a smooth contact with the wheel rim and reduce wheel-rail wear in the curved section. The top quenching layer is 10-12mm deep, and the hardened layer and the matrix are in a gradient transition to avoid peeling cracks due to sudden hardness changes, and adapt to high-frequency wheel-rail impact.
The rail waist is a load-bearing structure connecting the rail head and the rail bottom. It adopts a variable thickness design. The thickness of the middle section reaches 16mm, and the upper and lower ends gradually change to 18mm, forming a mechanical support similar to an "I" steel. This form makes the stress distribution of the rail waist more uniform when it is subjected to vertical bending moment, and the bending section coefficient reaches more than 3000cm³, which is 25% higher than that of 60kg heavy rails. Symmetrical bolt holes are set on both sides of the rail waist, with a hole spacing of 100mm and a hole diameter of 31mm, which accurately matches the installation requirements of 10.9 grade high-strength bolts to ensure the rigid fixation of the fastener system.
The rail bottom is a flat plate structure with a width of 150mm, which is the basis for the contact between the heavy rail and the sleeper. The flatness error of its bottom surface is controlled within 0.5mm/m to ensure full fit with the pad and disperse the vertical load transmitted by the rail head. The edge of the rail bottom is rounded with a radius of 5mm to avoid stress concentration when contacting the sleeper. In the seamless line, welding grooves are reserved at both ends of the rail bottom, with a groove angle of 45°, which is convenient for forming equal-strength joints during thermite welding or flash welding to ensure the longitudinal continuity of the track.
The three parts are formed in one piece through hot rolling process, and the center of gravity of the section is located 38mm below the rail head, forming the best force arm with the wheel load action point, so that the transmission efficiency of wheel-rail force through the rail head and rail waist to the rail bottom reaches more than 90%, providing a structural foundation for heavy-load transportation.
GNEE RAIL focuses on the import and export of GB standard rails. In addition to heavy rails, our main products include light rails, QU crane rails and various railway fasteners, which are widely used in railways, rail transit, port machinery and other fields.
Relying on a stable supply chain and strategic cooperation steel mills, we export our products to more than 30 countries and regions including Southeast Asia, Africa, the Middle East, and South America with competitive prices, efficient logistics and high-quality services.
We adhere to quality first, provide flexible trade solutions, and provide reliable rail products and technical support for global infrastructure.