TERM-OXIDATIVE-DEGRADATION
Oxidative Degradation
Chemical Degradation
Also: oil oxidation · lubricant degradation · oil aging · thermal oxidation
Canonical Definition
The chemical breakdown of lubricating or hydraulic oil through reaction with dissolved oxygen, generating oxidation byproducts including organic acids, aldehydes, ketones, and high-molecular-weight polymers (sludge precursors). Oxidation rate doubles for approximately every 10°C rise in oil temperature above 60°C (the Arrhenius rule for lubricant oxidation). Oxidation products increase oil viscosity and TAN, decrease TBN, reduce antioxidant additive content, and generate insoluble varnish deposits. Contamination by water and metallic catalysts (copper, iron) accelerates oxidation significantly.
Engineering Context
Oxidative degradation sets the fundamental limit on lubricant service life. All oil condition monitoring parameters — viscosity increase, TAN rise, TBN depletion, antioxidant depletion, and varnish potential — are direct indicators of oxidation progress. Oil temperature control below 80°C is the single most effective means of extending oil service life.
Related Technologies
Protection Systems
Knowledge Center Articles
KC-00 Governance Metadata
| Permanent ID | TERM-OXIDATIVE-DEGRADATION |
| Category | Chemical Degradation |
| Status | Published |
| Version | 1.0 |
| Last Reviewed | 2026-07-05 |