Influence of carbon layer hardness characteristics on RCF performance of carburized bearing steel and optimization of heat treatment process.

• Coupled rolling contact fatigue elastic-plastic damage model for carburized bearing steel. • Characterization of rolling contact fatigue with different thicknesses of carburized layer. • Relationship between the number of load cycles and the degree of subsequent material damage. • Optimization of carburizing heat treatment process for bearing steel. Being a pivotal element within high-speed train transmission systems, the mechanical attributes of bearings are of great significance to ensure the quality and safety of train operation. In this study, the rolling contact fatigue performance of bearing materials was tested to investigate the effects of different carbon layer characteristics on the rolling contact fatigue behavior. Combined with the thickness of carburizing layer, the elastoplastic coupling model of rolling contact fatigue damage of G20CrNi2MoA carburizing bearing steel was established. The model revealed the relationship between the number of load cycles and the degree of subsequent material damage. The model was used to calculate and predict the loading frequency of G20CrNi2MoA carburized bearing steel with excellent fatigue characteristics, which was 2.02 × 108 times before spalling. In addition, the carburizing heat treatment process for bearings was optimized based on the hardness gradient curves obtained, which provided valuable insights for improving the actual production process. [ABSTRACT FROM AUTHOR]