Corrosion Resistance in Steel Structures
Standard: EN ISO 12944-2:2001
Standard Information
- Standard Number: EN ISO 12944-2:2001
- Title: Paints and varnishes - Corrosion protection of steel structures by protective paint systems
- Part 2: Classification of environments
- Status: Current
Atmospheric Corrosivity Categories
The standard defines six atmospheric corrosivity categories:
- C1 (Very Low): Heated buildings with clean atmospheres
- C2 (Low): Rural areas with low pollution
- C3 (Medium): Urban and industrial atmospheres with moderate SO2 pollution
- C4 (High): Industrial areas and coastal areas with moderate salinity
- C5-I (Very High-Industrial): Industrial areas with high humidity and aggressive atmosphere
- C5-M (Very High-Marine): Coastal and offshore areas with high salinity
Durability Ranges
Expected durability of protection systems:
- Low (L): 2-5 years
- Medium (M): 5-15 years
- High (H): > 15 years
Environmental Factors
Key environmental factors affecting corrosion:
- Humidity and temperature
- Pollution levels
- Chemical exposure
- UV radiation
- Mechanical stress
- Salt concentration
Protection Requirements
Surface Preparation
- Cleaning and degreasing
- Removal of rust and scale
- Surface profile preparation
- Dust and contamination removal
Coating Systems
- Primer selection
- Intermediate coats
- Topcoat requirements
- Total system thickness
Application Guidelines
Critical application factors:
- Environmental conditions during application
- Application methods and techniques
- Drying and curing times
- Layer thickness control
- Quality control measures
Inspection and Maintenance
- Regular inspections
- Documentation of condition
- Touch-up procedures
- Maintenance planning
- Recoating schedules
Important Considerations:
- Correctly assess environmental conditions
- Choose appropriate protection system
- Ensure proper surface preparation
- Follow application specifications
- Maintain inspection records