Spalling / flaking
Material fragments break away from raceway or rolling-element surfaces after subsurface fatigue cracks reach the surface.
Probable causes
- Normal end of L10 fatigue life under the applied load
- Overload or shock beyond design duty
- Inadequate lubrication film (low κ)
- Contamination indentations acting as stress raisers
Corrective actions
- Verify equivalent load P and required C against ISO 281 life target
- Improve filtration / sealing; raise viscosity or change grease
- Check for misalignment and shaft deflection
- Replace bearing; inspect shaft and housing seats
References: ISO 15243 · ISO 281 · OEM failure analysis guides