Study on the fatigue and wear characteristics of four wheel materials

Abstract

The fatigue and wear characteristics of four different steel wheel materials are investigated in detail by using rolling contact fatigue and wear bench tests on a JD-1 apparatus, analyzing chemical composition and hardness, and performing profile analysis and micro-morphology analysis. The wear and fatigue behavior of one of the materials under different operation speeds is also investigated. The results show that the wear resistance of the materials has a positive correlation with their carbon content, while fatigue resistance has a negative correlation. Based on hardness analysis as a function of depth into the specimen, the thickness of layers with a steep hardness gradient has a negative correlation with the initial surface hardness in the tests using different materials. The hardness increments, however, have a positive correlation with initial surface hardness. The rolling tests on one material using different rotation speeds show that the hardness increments and the thickness of layers with a steep hardness gradient increase with the rotation speed. The analyses and experimental results demonstrate that two of the four materials exhibit good wear resistance and rolling contact fatigue resistance, making them suitable for either highspeed or heavy axle railroad operations.

Influence of thermal loading parameters and microstructure on the formation of stratified surface layers on railway wheels

“…39 A comparable effect is suggested for plastic deformation on the wheel treads in service, which leads to grain refinement of the near-surface microstructure. 26,[40][41][42][43] The chemical composition of the steel is expected to affect phase transformations [44][45][46] as it occurs when thermally inducing an SSL. Within this study the sample with the chemical composition of standard wheel steel grade ER7 shows an increased SSL thickness compared to the sample with the chemical composition of wheel steel ER-MA.…”

“…39 A comparable effect is suggested for plastic deformation on the wheel treads in service, which leads to grain refinement of the near-surface microstructure. 26,40–43…”

Fatigue damage mechanism of railway wheels under lateral forces

“…A DC motor drove the rail roller, and contact forces between rollers drove the wheel roller. Moreover, an opposing torque against the rotation direction was imposed on the axis of the wheel roller to generate a certain value of contact forces between wheel and rail rollers [30]. As the wheel roller is driven by contact forces, i.e.…”

“…In general, surface-initiated RCF depends on a number of interdependent parameters, such as the load [15], the slip ratio [27,28], the contact condition [29], the friction coefficient, the material defects [14], the wear and fatigue resistance of the material [30]. In practical cases, many factors affect the wear and fatigue behavior of the railway wheel, making it difficult to reliably quantify wheel and rail wear under a variety of operating conditions.…”