Hundred-meter-long rails are widely used in local railway construction projects, greatly promoting the rapid development of the national economy and driving regional progress. The independently developed PG4 (U78CrV) rails are laid in the world's largest transportation lines such as Shuohuang and Shenhua. The lines have complex environments such as small curve radii, heavy vehicle axles, and harsh rail stress. It is the largest production base for heavy-duty railway rails in China and also an important heavy-duty railway rail supplier in the world.