White etching cracks and other microstructural features have been investigated in two 100Cr6 steel bearings failed after several years of service in wind turbines. It is found that cracks in these bearings propagate predominantly through prior austenite grains in the tempered martensite structure. Both sharp and gradual transitions between the tempered martensite structure and white etching matter adjacent to the cracks are observed. Carbide particles in the transition regions are found to be finer than those in tempered martensite. It is suggested that structural refinement of these particles in the wind turbine bearings occurred at a late stage of white etching matter formation.
- White Etching Cracks
- Deformation and Fracture