Microinclusion and Fatigue Performanceof Bearing Rolling Elements

Many phenomena are involved in damage of rolling elements of bearings. Rolling contact fatigue is the main cause of failure, along with contact pressure related fatigue and dimensional instabilities effect. Most of those are well known, and are described by wide experimental, analytical and numerical literature. Damage phenomena are related to material properties and manufacturing processes, respectively. Particularly, the damage evolution might be affected by some microinclusions present in thematerial. This influence is related tomechanical properties, dimension, composition, shape and location of inclusions. This research activity is focused on the 100Cr6 steel alloys. Relation between microinclusions and fatigue life is here investigated. Results of experimental testing run on some test bench are compared to some analytical models for given set of operation conditions. Failures are then analysed to relate life of rolling elements to the microinclusion parameters. The research activity is aimed to investigate whether a microinclusion threshold parameter could be defined, to be related to the life bearing requirements. This analysis is performed by comparing analytical and experimental results of several models and different alloys.