Wear, plastic deformation and friction of two rail steels—a full-scale test and a laboratory study

• Published in: Wear Vol. 254; no. 1; pp. 80 - 93
• Main Authors: Olofsson, U., Telliskivi, T.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 2003; Amsterdam Elsevier Science; New York, NY
• Subjects: Applied sciences; Contact of materials. Friction. Wear; Exact sciences and technology; Friction; Friction, wear, lubrication; Lubrication; Machine components; Mechanical engineering. Machine design; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Plastic deformation; Rail; Wear; Plastic deformation; Lubrication; Rail; Friction; Wear; Service life; Ratchetting; Inelasticity; Sliding wear; Rail transportation; Rail steel; Experimental study; Tribology
• ISSN: 0043-1648; 1873-2577; 1873-2577
• DOI: 10.1016/S0043-1648(02)00291-0

Form change due to wear and plastic deformation on a rail can reduce the service life of a track. The purpose of this investigation was to study the development of these damage mechanisms on new and 3-year-old rails in a commuter track over a period of 2 years. The experimental results from the form measurements show that there was a significant change in rail profile due to wear as well as to plastic deformation. Plastic deformation and wear was a continuing process even for rail that had been in service for 5 years. The plastic deformation mechanism was plastic ratchetting. Compared with the UIC 900A grade rail, the form change was less for the UIC 1100 grade rail. However, the contact situation in terms of sliding velocity and contact pressure had more influence on form change than the change of material. The results from 3D surface measurement showed that there were different wear mechanisms involved at different parts of the rail. Mild wear dominated at the rail head, but at the rail edge severe wear clearly influenced the amount of wear. The severe wear showed traces of seizure. Material tests were performed on two different testing machines: a two-roller and a pin-on-disk machine. On the basis of results from the material testing, a simple wear map was constructed. In the wear map, the wear coefficient is presented as a function of sliding velocity and contact pressure. The results from laboratory tests showed that wear coefficient depended strongly on sliding velocity. The increase in the wear coefficient when increasing sliding velocity was due to a change of wear mechanism from mild wear to severe wear.