Compared with 60KG and 50KG heavy rails, 75KG heavy rails have the following advantages in terms of load-bearing capacity, stability, wear resistance and service life:
Higher load-bearing capacity
The 75KG heavy rail has a higher weight per unit length, which means that it has a thicker rail head, rail waist and rail bottom, and can withstand greater pressure and impact. In heavy-duty railway transportation, such as the Daqin Railway Coal Transportation Line, 75KG heavy rails can withstand train loads with an axle weight of 30 tons or more, while 60KG and 50KG heavy rails may experience deformation, increased wear and other problems when subjected to such a large load for a long time.
Better stability
Due to the larger size and heavier weight of the 75KG heavy rail, it has better stability after track laying. When the train is running at high speed or frequently braking and starting, the 75KG heavy rail can better maintain the geometry of the track and reduce the lateral displacement and longitudinal creep of the track. For example, in the turnout area of high-speed railways, the use of 75KG heavy rails can improve the stability of the turnouts and ensure the safe and smooth passage of trains in the turnout area.
Stronger wear resistance
75KG heavy rails are usually made of high-performance alloy steel, such as U78CrV, etc., with higher surface hardness of the rail head and better wear resistance. On busy railway trunk lines, such as the Beijing-Guangzhou Line and the Beijing-Shanghai Line, the train operation density is high, and the 75KG heavy rails can withstand more wheel rolling, reduce the wear and fatigue cracks on the rail surface, and extend the service life of the rails. In contrast, under the same use conditions, 60KG and 50KG heavy rails may wear faster and require more frequent rail grinding and replacement.
Longer service life
Combining the above advantages, the 75KG heavy rail has a relatively long service life because it can withstand greater loads, maintain better stability and has stronger wear resistance. On some heavy-load railways and busy trunk railways, the service life of 75KG heavy rails can be extended by about 20% - 50% compared with 60KG and 50KG heavy rails. This not only reduces the number of rail replacements and maintenance costs, but also reduces the railway transportation interruption time caused by rail replacement, thereby improving the efficiency and economy of railway transportation.
