Knowledge Base Menu

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