Effects of lubrication on wear and rolling contact fatigue behavior of class B wheel steels against R350HT rail steels using a twin-disc wear simulator

Abstract

Wear and rolling contact fatigue (RCF) are major causes of delays and unavailability of rail systems. The presence of lubricants at the rail and wheel interface influences wear and RCF. Lubricants include naturally occurring types, such as water from rain and leaves from trees next to rail lines, and materials applied on purpose to help improve adhesion and friction, such as friction modifiers, greases, and traction gels. The aim of this work was to study the wear behavior of AAR class B wheel versus R350HT rail materials in the presence of water and oil in comparison with the dry condition. There is currently a lack of knowledge regarding the combination of these materials in a twin-disc simulator, and this work provides information on their impact on RCF and wear performance for use by the rail industries. It was found that wear was much lower when water or oil was introduced at the wheel–rail interface compared to dry conditions, for all slip ratios. When water was used, the main cause of RCF was found to be fluid crack pressurization. The RCF cracks were also observed under dry contact.