U71Mn what does "U" mean in the rail?
U is the rail steel number.
With the increase of axle load and the increase of vehicle speed, the rail type of rail becomes more and more heavy, and the performance develops to high strength. In the manufacturing process, from hot rolling to full heat treatment after rolling.
Rail steel (rail, steel) is used for the manufacture of locomotives, cranes and other rail steel for professional use. Most of the rail steel by oxygen open hearth and oxygen converter smelting and rolling by. Rail used in the main wear and long-term repeated load, so the requirements of wear, pressure, fatigue, welding and good toughness.
