Atmospheric corrosion accounts for more failures on both a tonnage basis and cost basis than any other type of environmental corrosion. Tremendous amounts of steel in automobiles, bridges ad buildings are exposed to the atmosphere and attacked by oxygen and water. The corrosion severity is increased when salt, sulfur compunds and other atmospheric contaminants are present.

Atmospheric environments can be classified as:

• Industrial
• Marine
• Rural
• Indoor

Industrial environments contain sulfur compounds, nitorgen compounds, and other acidic agents that can promote the corrosion of metals. In addition, industrial environments contain a heavier loading of airborne particles, which also contribute to corrosion. Marine environments are characterized by the presence of chloride, an ion that is particularly detrimental to the corrosion behavior of many metals systems. Rural environments are the least corrosive of the atmospheric environmets, being characterized by lower levels of acidic compounds and other aggressive species.

Factors Affecting Atmospheric Corrosion

The principal factors influencing atmospheric corrosion for a given metal are moisture, temperature amd the presence of contaminants in the environment.

• Moisture
• Temperature
• Contaminants
• Corrosion Control