The global annual demand for heavy rail (such as 60kg/m, 75kg/m) is about 5 million tons, mainly used in high-speed railways, heavy-duty railways and urban rail transit. China is the world's largest producer (accounting for 60% of the market), but the high-end market is still dominated by Japan's Nippon Steel, Europe's Tata Steel (formerly Corus) and Voestalpine.
Focus of technical competition
1. High-purity smelting
- European companies use LF+RH vacuum degassing process to control the hydrogen content in steel to ≤1.5ppm and reduce white spot defects.
- China Baowu and Anshan Iron and Steel have introduced ESR (electroslag remelting) technology to improve the internal density of rails.
2. Extra-long fixed-length rails
- Traditional fixed-length rails are 25 meters, while 36-meter and 50-meter extra-long rails can reduce welding joints and reduce high-speed rail wheel-rail noise.
- The continuous casting and rolling integration technology developed by Nippon Steel of Japan can produce 100-meter heavy rails, but the equipment investment cost is extremely high.
3. Corrosion-resistant coating technology
- The demand for zinc-aluminum-magnesium coated (ZM) rails in marine climate regions (such as Southeast Asia and the Middle East) is growing, and its corrosion resistance is 5 times that of ordinary rails.
- The organic-inorganic composite coating developed by USS (now Cleveland-Cliffs) in the United States can adapt to the temperature difference of -40℃~80℃.
