SERVICE LIFE CHART FOR HOT-DIP GALVANIZING COATINGS

Source: American Galvanizers Association
* Service life is defined as the time to 5% rusting of the steel surface.
 

Rural

   Suburban
  Temperate Marine   Tropical Marine
  Industrial   ASTM Coating
Thickness
     
The Service Life Chart (SLC) was developed based on decades of corrosion rate data collected from galvanized steel samples exposed to the five defined environments in cities all over the world, and a corrosion prediction model based on statistical methods and neural network technology.
The data points of the SLC are based on macroscopic environmental data and, thus, may vary from the actual corrosion rate observed due to site-specific environmental conditions.
Atmospheric levels of relative humidity, sulfur dioxide, airborne salinity, precipitation, and temperature influence actual corrosion rates in a specific geographic location.
Parameters such as wind direction, frequency drying, alloying composition, and surface orientation may also affect corrosion rates, but because of their variable and usually minor nature, are not included in the SLC model.