Corrosion of stainless steel
ISO 9223 provides a general guideline for corrosion classes in relation to stainless steel. Please consult us for specific guidance before starting a project.
| Corrosivity category | Corrosivity | Typical indoor environments | Typical outdoor environments | Alloys |
| C1 | Very low | Offices, schools and museums. | Certain deserts, Central Arctic and Antarctica. |
430/4016 |
| C2 | Low | Storage rooms/premises and sport halls. | Rural areas and small towns, deserts and subarctic regions. | 430/4016 304L/4307 Duplex 2101 |
| C3 | Medium | Food processing plants, laundries, breweries and dairies. | Urban areas and a few coastal areas with low effect from the sea. Subtropical and tropical zones with low pollution in the atmosphere. |
316L/4404 Duplex 2205 |
| C4 | High | Industrial processing plants and swimming pools*. | Contaminated urban areas, industrial areas, certain coastal areas, areas exposed to strong de-icing salts. Subtropical and tropical zone, atmosphere with medium pollution. |
316L/4404 |
| C5 | Very high | Mines, caverns for industrial purposes, unventilated sheds in subtropical and tropical zones. | Industrial areas, coastal areas in general, sheltered positions on coastlines. | 904L/4539 254 SMO Duplex 2507 |
| CX | Extreme | Unventilated sheds/buildings in humid tropical zones exposed to outdoor factors to an extent that is particularly corrosion-stimulating. | Extreme industrial areas, coastal and offshore areas, areas often exposed to contact with salts. | 254 SMO Duplex 2507 |