What is Copper Strip Corrosion? The steps for conducting the test and various methods used
Copper Corrosion Test establishes the level at which a lubricant will corrode copper-containing materials (i.e., bronze, brass). The degree of corrosion is tested for many products like lubricating oil, petroleum products, aviation fuels, kerosene, automotive fuels, automotive gasoline, solvents, distillate fuels, diesel fuels and many other products.
At elevated temperature, a polished copper strip is dipped in 30 ml of sample and thereafter the copper strip is compared with the ASTM copper corrosion chart for the degree of corrosion which is shown below.
The steps for performing the Copper Strip Corrosion Test
Standardisation of the Copper Strip Corrosion Test is provided by IP 154 and ASTM D130. Other temperatures may be used if specified, although 100 °C is the usual temperature at which the test is conducted.
The steps for the Copper Strip Corrosion Test are summarised as follows:
- The test equipment consists of a glass test tube, a cork stopper, and a Prepare the test apparatus and copper strips. With an appropriate solvent, polish and clean the copper strips.
- Fill the test tube with 30 ml of
- The copper strip should be carefully inserted into the lubricant until it is fully
- The test tube should be heated by placing it in a heating bath and heating it for three hours at the desired temperature, typically 100 °C.
- In order to evaluate the corrosion’s severity, take the copper strip out of the test tube and let it Check the copper strip’s surface for deposits or discolouration. Compare the strip’s appearance to the expected classification.
| Class | Designation | Description | ||
1 | 1 | Slight Tarnish | 1a | Light orange, almost the same as a freshly polished strip |
1 | 1b | Dark orange | ||
2 |
2 | Moderate | 2a | Claret Red |
2 | 2 | Lavender | ||
| 2c | 2c | Multicoloured with lavender blue and / or silver overlaid on claret red | ||
2 | 2 | Silvery | ||
2 | 2e | Brassy or gold | ||
3 | 3 | Dark Tarnish | 3a | Magenta overcast on brassy strip |
3 | 3 | Multicoloured with red and green showing (peacock), but no grey | ||
4 | 4 | Corrosion | 4a | Transparent black, dark grey or brown with peacock barely showing |
| 4 b | 4 | Graphite or lusterless black | ||
| 4c | 4c | Glassy or jet black | ||
Atlas Lab uses the following methods for conducting copper corrosion test :
| Method | Description |
| ASTM D130 | Standard Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip Test |
| IP 154 | Petroleum products – Corrosiveness to copper – Copper strip test |
| ISO 2160:1998 | Petroleum products — Corrosiveness to copper — Copper strip test |
| DIN 51759-1 | Testing of liquid mineral oil products; method of test for copper corrosion; copper strip test |
| BIS 1448 : Part 51 | Corrosiveness to Copper – Copper Strip Test |
Interpreting the Copper Strip Corrosion Test Results
Based on the degree of corrosion visible on the copper strip, the findings of the copper strip corrosion test are interpreted. The term “non-corrosive” refers to lubricants that do not cause corrosion (Class 1), whereas “borderline” or “mildly corrosive” may refer to lubricants (Class 2) that produce only little corrosion. Highly corrosive lubricants are those that produce moderate (Class 3) or severe (Class 4) corrosion.
Atlas Lab uses the following test equipment to carry out copper corrosion test :
