Effect of oil and water mixtures on adhesion in the wheel/rail contact

Abstract

This article details the findings of a series of twin disc machine adhesion tests that investigated the effects of oil and water mixtures on adhesion at the wheel/rail interface. Oil was found to have a dominant effect on adhesion in the presence of water. Surfaces coated with oil at 4.7×10−3 g/cm2 and sprayed with water had levels of adhesion similar to those coated by a replenishing supply of oil. The tests showed that drying a wet contact can initially give a reduction in adhesion, that increased roughness results in increased adhesion in the presence of oil, and that increased contact pressure improves adhesion in the presence of oil.

Influence of Different Application of Lubricants on Wear and Pre-existing Rolling Contact Fatigue Cracks of Rail Materials

“…Furthermore, the leaf slurry due to the leaf residue film formation would cause low adhesion [20]. If oil and water are present together (regardless of amount), oil has the dominating effect and adhesion coefficient remains at low levels similar to having oil alone [21]. At present, many friction modifiers (FM) have been used to improve the friction level of the wheel/ rail interface [22,23].…”

Tribology of the wheel–rail contact – aspects of wear, particle emission and adhesion

“…The effects of oil and water mixtures were studied using a twin disc test rig [61] (shown in Figure 26) and a wheel-rail simulation facility [62] (shown in Figure 27). Both of them found that it is the oil in the mixture that has a dominating effect in reducing adhesion/friction.…”

“…Figure 26. Creep curves for oil and water mixture tests obtained from a twin-disc test rig [61] with rolling speed at around 1m/s Figure 27. Graphs of adhesion coefficient versus number of cycles obtained from a wheel-rail simulation facility [62] with rolling speed at around 90 km h -1…”

Application of Fastsim with variable coefficient of friction using twin disc experimental measurements

“…Two levels of pressure are considered for dry surfaces and with the presence of water and oil. The creep curves collected for a maximum Hertzian pressure of 1500 MPa are taken from the previous section; the creep curves for 900 MPa are extracted from [24].…”