Surface treatment of rail to enhance rolling contact fatigue and wear resistance: Combined spot laminar plasma quenching and tempering method

Abstract

The railway industry faces the challenge of improving the fatigue and wear resistance of rails simultaneously. Laminar plasma quenching (LPQ) can enhance wear resistance but may result in severe rolling contact fatigue (RCF) damage. This study proposes a combined LPQ and tempering method to address this issue and evaluates its effect on rail RCF damage and wear resistance using twin-disc tests. The findings demonstrate that tempering diminishes the grain density and mitigates the lattice distortion in the quenched zone of LPQ rails, thereby enhancing the RCF resistance in that zone. This treatment leads to a substantial reduction in surface fatigue cracks and spalling of the rails and a wear resistance improvement of over one-fold compared to ordinary rails. Thus, this rail surface treatment approach effectively improves both the fatigue and wear resistance of rails simultaneously.