Industry knowledge
Manufacturing materials and performance requirements of national standard rails
National standard rails are generally made of high-quality carbon steel or low-alloy steel, and the material codes are mainly U71Mn, U75V, U78CrV, etc. These steel grades have good toughness, tensile strength and wear resistance, and are suitable for long-term use needs of high-speed trains, large-tonnage freight and high-frequency operation lines.
China's national standards have strict requirements on rail performance. For example, U71Mn rails must have a tensile strength of not less than 880MPa, a yield strength of not less than 785MPa, and elongation and impact toughness indicators must also meet the standard standards. At the same time, for rails that are frequently used and severely worn, heat treatment processes such as quenching rails can also be used to improve hardness and durability.
In terms of manufacturing technology, national standard rails are hot-rolled and formed, and through automated straightening, cutting, ultrasonic flaw detection and other processes to ensure that the finished product has accurate size, smooth surface, and no internal defects. This series of performance control standards guarantees the service life and operation safety of the rails.
