The current paper presents a new multi-layer model of low adhesion between railway wheel and rail. The model proposes that when leaves are crushed between railway wheels and rail, both a coated slippery layer and a chemically reacted, easily sheared surface layer are formed. Elemental depth profiling reveals that the chemically reacted, easily sheared surface layer contains substances such as P and Ca. Both the coated slippery layer and the chemically reacted, easily sheared surface layer must be removed to get proper adhesion between railway wheel and rail.
ForslövL. Wheel slip due to leaf contamination. Swedish National Rail Administration TM 1996 03 19, Borlänge, Sweden, published in Swedish, 1996.
7.
OlofssonU.SundvallK.Influence of leaf, humidity, and applied lubrication on friction in the wheel-rail contact: pin-on-disc experimentsProc. Instn Mech. Engrs, Part F: J. Rail Rapid Transit, 2004, 218, 235–242.
8.
LewisR.Dwyer-JoyceR.Wear at the wheel/rail interface when sanding is used to increase adhesionProc. IMechE, Part F: J. Rail and Rapid Transit, 2006, 220 (1), 29–41.
9.
HarrisonH.McCanneyT.CotterJ.Recent development in COF measurements at the rail/wheel interface. InContact mechanics and wear of rail/wheel systems, Tokyo, Japan, 25–27 July 2000.
10.
OlofssonU.TelliskiviT.Wear, friction and plastic deformation of two rail steels — full-scale test and laboratory studyWear, 2003, 254, 80–93.
11.
FulfordC. R.Review of low adhesion research. Report published by the Rail Safety and Standards Board, UK, 2004.
12.
OlofssonU.LewisR.Tribology of the wheel-rail contact In A handbook of railway vehicle dynamics (Ed. IwnickiS.), 2006, pp. 121–141 (Swets & Zeitlinger).
13.
BowdenF. P.TaborD.The friction and lubrication of solids, parts I and II, 1950 (Clarendon Press, Oxford).
ZhaoY. W.LiuJ. J.ZhengL. Q.The oxide film and oxide coating on steels under boundary lubrication. In Proceedings of the 16th Leeds-Lyon Symposium onTribology, Lyon, 1989, pp. 305–311.
