Corrosion resistance
The concept of corrosion includes all chemical and electrochemical processes that result in the spontaneous and continuous degradation of metal and alloy surfaces. Some metals form a protective oxide layer on the surface that protects the rest of the metal from further corrosion. These are called protective films. Aluminum forms such a film, which, under the action of oxygen in the air, is covered even at room temperature with a thin layer of aluminum oxide, making it resistant to atmospheric agents.
| ALLOY | CONDITION | Corrosion resistance | |||||||
|---|---|---|---|---|---|---|---|---|---|
| COA | COIA | COMA | CORA | SCOA | EXCA | ICOA | PCA | ||
| 1050 | 0 | 6 | 6 | 5 | 6 | 6 | 6 | 6 | 6 |
| 1050 | Hx2 | 6 | 6 | 5 | 6 | 6 | 6 | 6 | 6 |
| 1050 | Hx4 | 6 | 6 | 5 | 6 | 6 | 6 | 6 | 6 |
| 1050 | Hx6 | 6 | 6 | 5 | 6 | 6 | 6 | 6 | 6 |
| 1050 | Hx8 | 6 | 6 | 5 | 6 | 6 | 6 | 6 | 6 |
| 2007 | T4 | 3 | 6 | 3 | 6 | 4 | 3 | 4 | 3 |
| 2011 | T6 | 3 | 3 | 3 | 4 | 5 | 4 | 3 | |
| 2014 | T4 | 3 | 3 | 3 | 4 | 4 | 3 | 4 | 4 |
| 2017 | T4 | 3 | 4 | 3 | 4 | 4 | 3 | 4 | 4 |
| 2024 | T3 | 3 | 4 | 3 | 4 | 4 | |||
| 2024 | T4 | 3 | 4 | 3 | 4 | 4 | |||
| 3003 | Hx2 | 6 | 4 | 5 | 6 | 6 | 6 | 6 | 6 |
| 3003 | Hx4 | 6 | 6 | 5 | 6 | 6 | 6 | 6 | 6 |
| 5005 | Hx2 | 6 | 5 | 6 | 6 | 6 | 6 | ||
| 5052 | Hx2 | 6 | 6 | 5 | 6 | 6 | 6 | 6 | 6 |
| 5083 | Hx2 | 6 | 6 | 5 | 6 | 5 | 6 | 5 | 6 |
| 5754 | Hx2 | 6 | 6 | 6 | 6 | 5 | 6 | 5 | 6 |
| 6060 | T6 | 6 | 5 | 5 | 6 | 6 | 6 | 6 | 5 |
| 6063 | T6 | 6 | 5 | 5 | 6 | 6 | 6 | 6 | 5 |
| 6082 | T6 | 5 | 5 | 5 | 5 | 6 | 5 | 5 | 5 |
| 7075 | T6 | 3 | 3 | 3 | 4 | 4 | 3 | 4 | 4 |
| Legend for Corrosion Parameters | |||
|---|---|---|---|
| COD | Meaning of Code | Value Scale | Possible Values |
| COA | Corrosion Index, General | Scale: 2-7 | Missing information |
| COIA | Corrosion Index in Industrial Atmosphere | Scale: 2-7 | Not applicable |
| COMA | Corrosion Index in Marine Environment | Scale: 2-7 | Inadequate |
| CORA | Corrosion Index in Rural Environment | Scale: 2-7 | Not recommended |
| SCOA | Corrosion Index under Stress | Scale: 2-7 | Acceptable |
| EXCA | Exfoliation Corrosion Index | Scale: 2-7 | Good |
| ICOA | Intergranular Corrosion Index | Scale: 2-7 | From good to very good |
| PCA | Operating Corrosion Index | Scale: 2-7 | Very good |
| Excellent | |||
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