Brinelling
How does true brinelling differ from false brinelling in root cause?
True brinelling is a force problem (overload/impact) causing plastic deformation without material loss; false brinelling is a vibration problem causing fretting wear with material loss (magnetite).
Can brinelling be detected via vibration analysis?
Yes; true brinelling creates periodic impacts at the rolling element passing frequency, while false brinelling manifests as high-frequency noise from fretting wear.
Is brinelling a fatigue failure?
No; it is a threshold failure where yield strength is exceeded, distinct from fatigue cracks or abrasive wear.
Brinelling is the permanent indentation of a bearing raceway or rolling element surface caused when contact stress exceeds the material’s yield strength, resulting in irreversible plastic deformation. Named after the Brinell hardness test, it includes true brinelling from static overload or impact and false brinelling from micro-vibrations causing fretting wear.
In shop floor maintenance, brinelling is a critical failure mode identified during vibration analysis or visual inspection of non-rotating assets. Technicians log it in CMMS as a threshold failure requiring immediate replacement. True brinelling results from improper installation (e.g., hammering) or transport impacts, while false brinelling arises from vibration on stationary bearings. Preventive measures include using hydraulic presses for installation, securing assets against vibration during storage, and ensuring dynamic lubrication in oscillating applications.
Hammer installation: Direct impact during mounting creates immediate true brinelling indentations.
Vibration on stationary assets: Storing bearings or machinery in vibrating environments without dithering protection causes false brinelling corrosion and fretting.
Debris contamination: Hard particles entering the bearing act as localized load points, exceeding yield strength and causing false brinelling-like pits.