Effects of solid friction modifier on friction and rolling contact fatigue damage of wheel-rail surfaces

Abstract

In railway network, friction is an important factor to consider in terms of the service behaviors of wheel-rail system. The objective of this study was to investigate the effect of a solid friction modifier (FM) in a railway environment. This was achieved by studying the friction, wear, and rolling contact fatigue (RCF) damage on the wheel-rail materials at different slip ratios. The results showed that when a solid FM was applied, the friction coefficient decreased. After the solid FM was separated from the wheel-rail interface, the friction coefficient gradually increased to its original level. With the application of the solid FM, the wear rates of the wheel-rail decreased. In addition, the thickness and hardness of the plastic deformation layers of the wheel-rail materials were reduced. The worn surfaces of the wheel-rail were dominated by pits and RCF cracks. Without the FM, RCF cracks ranged from 84 to 120 µm, and subsurface cracks were generated. However, with the FM, RCF cracks ranged from 17 to 97 µm and no subsurface cracks were generated. These findings indicate possible methods of improving the performance of railway rolling stock by managing friction, and reducing wear and permanent RCF damage affecting both the wheels and rails.

Shear properties of top-of-rail products in numerical modelling

“…Compared to other studies on different scales 2,5,6 the coefficient of adhesion range between 0.1 and 0.2 seems to be very typical for rolling-sliding tests with moderate amounts applied. The results for SFM are in line with studies, 15,17 which suggest a coefficient of adhesion of around 0.3. Aside from the dry WFM, all these results can differ depending on the application amount, as was discussed with Figure 9.…”

“…14 Solid stick products for wheel tread have advantages in an easy application system and no liquid base that would be needed to spread the substance across the rail. The friction values for the solid stick are reported [15][16][17] to be around 0.3.…”

The effect of fine particle peening on aviation gear performance, part II: Rolling contact fatigue

“…In engineering, various surface strengthening technologies are commonly employed to improve the surface integrity of gears and enhance their rolling contact fatigue performance. 1 These technologies include surface coating, 2 shot peening, 3,4 and barrel finishing. 5 To achieve significant improvements in rolling contact fatigue performance of gear, it is essential to have a comprehensive understanding of the effects of surface integrity on their fatigue resistance after strengthening processes.…”

Effect of Heat Treatment Process on the Microstructure and Hardness of Train Wheel Material

“…Train wheel that are used for a certain time will experience wear because of the friction between the wheel and rail [4][5][6]. If it cannot be repaired, the wheel must be replaced.…”