GB 50KG heavy rails are usually made of manganese-containing alloy steels such as U71Mn, and their main components include:
Carbon (C): The content is generally around 0.65% - 0.75%. Carbon is an important element that affects the strength and hardness of steel. An appropriate carbon content can improve the strength and wear resistance of the rail.
Manganese (Mn): The content is about 1.10% - 1.50%. Manganese can improve the strength and toughness of steel, increase the wear resistance and fatigue resistance of rails, and also improve the welding performance of steel.
Silicon (Si): The content is usually 0.15% - 0.35%. Silicon can enhance the strength and hardness of steel, improve the elastic limit and yield strength of rails, and help improve the bearing capacity of rails.
Phosphorus (P): The content generally does not exceed 0.035%. Phosphorus is a harmful element. Too high a content will cause cold brittleness in steel and reduce the toughness and welding performance of steel. Therefore, its content needs to be strictly controlled.
Sulfur (S): The content is usually not higher than 0.035%. Sulfur is also a harmful element. It can cause hot brittleness in steel and reduce the mechanical properties of steel, especially toughness and fatigue strength. Therefore, its content must be strictly limited.
