New insight on wheel flange/rail gauge lubrication: Effect of lasered microtexture shapes on the wear and fatigue behaviour of wheel/rail steels

• Published in: Wear Vol. 498-499; p. 204310
• Main Authors: Liu, Ji-hua, Yu, Pi-jie, Zhou, Yu-jun, Xu, Zhi-biao, Li, Yong-jian, Li, Peng, Zhao, Zheng, He, Cheng-gang, Shen, Ming-xue
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.06.2022; Elsevier Science Ltd
• Subjects: Coefficient of friction; Damage; Dynamic pressure; Fatigue failure; Friction reduction; Greases; Hot rolling; Laser surface texture; Lubricating greases; Microtexture; Plastic deformation; Rail steels; RCF; Rolling contact; Spalling; Storage capacity; Structural steels; Wear; Wear mechanisms; Wear rate; Wheel flange/rail gauge lubrication; Wheel flange/rail gauge lubrication; RCF; Storage capacity; Wear; Laser surface texture
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/j.wear.2022.204310

Three types of differently shaped lasered microtextures (microdimples) were produced on the surface of a U75V hot-rolled rail roller with a TY-FM-20S laser marking machine. Wheel flange/rail gauge lubrication starvation tests of four kinds of rail samples running against CL60 wheel samples were carried out, and the friction properties of the wheel/rail steels were studied. The results indicate that the injection of lubricating grease dominates the friction coefficient reductions and that the lubricating effects are closely related to the shapes of the lasered microtextures; for instance, the rectangular and rhombic textures show a better lubricating effect. Furthermore, the wear rates depend on the wear mechanism of the wheel/rail steel; for example, delamination and spalling always result in severe wear while peeling results in mild wear. The materials from the rolling-sliding surface to the matrix region of the wheel/rail materials can be divided into three parts: the plastic deformation region, transition region and undeformed matrix region. The average crack length and angle values of the textured rail and coupled wheel steels are much smaller than those of the untextured rail and coupled wheel steels; thus, the textured rail and coupled wheel steels exhibit better rolling contact fatigue (RCF) resistance. The effects of the lasered microtextures shapes on the wear and fatigue damage are determined based on the fluid dynamic pressure on the microtexture. Notably, rhombic lasered microtextures can be adopted to improve the grease storage capacity, thereby reducing wear and fatigue damage. •Three types of differently shaped lasered microtextures were produced on the rail surface.•Lubrication starvation tests of four kinds of rail samples were carried out.•Lubricating effect, wear and rolling contact fatigue behaviours were proposed and studied.•The textured rail and coupled wheel steels demonstrated better RCF resistance.•The lubricating and damage mechanism of textured rail were analysed and revealed.