Tribological Properties of a New Alloy Laser Cladded on Hypereutectoid Rails

To overcome the previous limitations imposed by standard laser cladding alloys, a novel iron-based laser cladding alloy, SS415, is developed and investigated. The wear and rolling contact fatigue resistance properties of the novel SS415 laser cladded on a premium railway hypereutectoid rail are experimentally investigated using a custom-made roller-on-disc test machine. The obtained results are compared with our previously published results of non-clad rail and the standard iron-based cladding alloys, namely, 410L and SS420, specimens under the same conditions. The accumulated wear rate and the pileup area were quantified with the aid of an optical profilometer. The obtained results were correlated to in-depth wear surface characterization using optical microscopic images. The experimental results showed that the novel SS415 exhibits favorable hardness variation, more ductile behavior, promising work hardenability, and a 95% reduction in the wear rate, in comparison to the non-cladded samples. Moreover, the SS415 cladding resulted in less surface damage and the lowest degree of third-body abrasive wear modes, after the completion of the rolling contact cycles. Based on this investigation, the novel SS415 is a promising iron-based laser cladding alloy that offers the best wear and fatigue performance compared to both 410L and SS420 cladded samples. Additionally, this novel alloy offers significantly improved mechanical and tribological properties compared to the two standard alloys.