Effect of normalisation on the microstructure and wear resistance of U75V rail welded joints in desert service environments

To elucidate the wear mechanism of rail steel welded joints in desert environments, we investigated the high- temperature friction and wear performance of U75V flash-butt welded rails across weld joints (normalised and non-normalised) as well as the base material at temperatures of 60, 200, and 300 degrees C. Owing to debris accumulation and the oxidised lubricating layer produced by the frictional process, all specimens exhibited elevated wear volumes accompanied by reduced friction coefficients with increasing temperature. The wear mechanism transitioned from adhesive wear to intense adhesive wear and ultimately delamination wear. Notably, owing to an optimised grain structure, the normalised joint demonstrated superior resistance against wear compared to its non-normalised counterpart under high-temperature conditions. These findings are anticipated to enhance rail quality within desert environments.