Structures
Steel is widely used across various industries such as infrastructure, transport, construction, oil and gas, and petrochemicals. It is produced by removing oxygen and impurities from iron ore, and combining it with carbon and other elements to create steel. However, when steel comes in contact with water and oxygen, it undergoes a chemical reaction and reverts to its original form, iron oxide.
To protect steel from corrosion, various measures are taken. Protective coatings are applied to steel surfaces to protect the steel from the onset of corrosion. Cathodic protection is also utilised for immersed and buried steel surfaces. The speed at which steel deteriorates depends on the specific environment it is exposed to. Steel structures in wet and damp environments experience faster rusting compared to those in warm and dry environments.
The corrosivity of different environments to steel structures is classified in ISO 12944-2, which provides detailed information on these environments.
| Corrosivity Category | Examples of Typical Environment | |
|---|---|---|
| Exterior | Interior | |
| C1 Very Low | Heated buildings with clean atmospheres, e.g. offices, shops, schools, hotels | |
| C2 Low | Atmospheres with low level of pollution: mostly rural areas | Unheated buildings where condensation can occur, e.g. depots, sports halls |
| C3 Medium | Urban and industrial atmospheres, moderate sulfur dioxide pollution; coastal areas with low salinity | Production rooms with high humidity and some air pollution, e.g. food-processing plants, laundries, breweries, dairies |
| C4 High | Industrial areas and coastal areas with moderate salinity | Chemical plants, swimming pools, coastal ships and boatyards |
| C5 Very High | Industrial areas with high humidity and aggressive atmosphere and coastal areas with high salinity | Buildings or areas with almost permanent condensation and with high pollution |
| CX Extreme | Offshore areas with high salinity and industrial areas with extreme humidity and aggressive atmosphere and sub-tropical and tropical atmospheres | Industrial areas with extreme humidity and aggressive atmosphere |
To ensure a long-lasting service life, coating systems need regular maintenance, especially when used in various corrosive environments. Conducting coating surveys is crucial for verifying and maintaining accurate and consistent data. Coatings Radar offers the necessary tools to accomplish this goal.