Aging apparatus “RapidOxy
In this process, the oxidation process is significantly accelerated by increasing the temperature and an excess of pure oxygen. In addition, the grease sample is spread on a catalyst plate (steel or copper) in the draft standard according to DIN 51830-2. This ensures that the test is particularly close to the application.
The device documents the pressure curve over time. From the RapidOxy aging results at two temperatures, the Aarhenius activation energy can be calculated.
A new approach is that a so-called “furnace aging” with regular flow curve measurement is carried out in parallel. The grease to be tested is applied thinly to a catalyst plate. A sample is taken from the furnace at regular intervals and the flow behavior is documented by means of rheometer measurements (see DGMK Project 820 and activities in DIN-AK 51830).
Using these results, statements can be made about the grease service life in a specific application.
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Parameter |
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Temperature range |
Up to 180°C |
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Test duration |
Until pressure drop is 30% or buckling point is reached (usually 8 h to 500 h) |
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Sample quantity |
Typically 1 g or 4 g |
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Catalysts |
Sheets of any material (typically copper, steel) |
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Up to 1800 kPa (typical 8 bar oxygen) |
Standard tests
- DIN 51808 – Determination of oxidation resistance of lubricants – Oxygen method
- DIN 51830-1:Testing of lubricants – Determination of oxidation stability of greases – Part 1: Rapid method.
- mDIN 51830-2: Aging resistance of greases
- ASTM D 8206 Oxidation Stability of Lubricating Greases – Rapid Small Scale Oxidation Test (RSSOT)