The assignment of a steel component to a corrosivity category according to DIN EN ISO 12944-2 indicates the type and extent of the corrosion-relevant influences from the environment on the component and the mass loss (in g/m2) to be expected due to corrosion after one year. Based on the examples in Tables 1 and 2 of DIN EN ISO 12944-2, the assignment can also be made as an estimate depending on the respective installation environment. It forms the basis for determining the type and extent of the necessary corrosion protection measures on the component.
Categories for components in contact with air:
- C1 (insignificant load): Heated indoor spaces without increased condensation, e.g. offices, schools, shops.
- C2 (low pollution): Outdoor: (predominantly rural) environments with low air pollution. Indoors: Unheated indoor spaces with increased condensation, e.g. warehouse buildings, sports halls.
- C3 (moderate pollution): Outdoor: urban and industrial atmosphere with moderate air pollution. Indoors: Production rooms with high humidity and low air pollution, e.g. breweries, dairies, laundries.
- C4 (heavy load): Outdoor areas: industrial areas and coastal areas with moderate salt pollution. Indoor areas: Chemical plants, swimming pools
- C5-I (very heavy exposure to industrial influences): Outdoor: Industrial areas with high humidity and aggressive atmospheres. Interior: Buildings with almost permanent condensation and heavy air pollution.
- C5-M (very heavy exposure to marine influences): Outdoor: Coastal and off-shore with high salt pollution in the air. Interior: Buildings with almost permanent condensation and heavy air pollution.
Categories for components in water and soil:
- Im1 components in freshwater, e.g. structures in rivers and lakes
- Im2 components in sea or brackish water, e.g. lock gates, structures in port areas and off-shore.
- Im3 components in the ground, e.g. sheet piling, tanks and pipes made of steel.
Source: bauwion
