TYPES OF ENVIRONMENTS

Chemical / Marine:
Offshore oil rigs and ships. Airborne salts and chemical pollutants may serve to stimulate corrosion. Humidity and seawater provide electrolytes, which also hasten the process.

Chemical / High Humidity:
Coastal oil refinery. Here gases, chemicals and high humidity stimulate corrosion.

Marine / High Humidity:
Splash zone platform piping. The presence of moisture and salt particles provide a very active electrolyte. The splash zone area (mid-tide level to 12 ft above high tide) suffers particular high corrosion.

Chemical / Low Humidity:
Inland oil refinery. Low humidity makes less corrosive environment than high humidity. But presence of gases and chemicals can stimulate corrosion.

Rural / Low Humidity: Inland rural railroad bridge, buildings. Least corrosive because clean air provides no airborne contaminants and moisture is not present to serve as an electrolyte.

Corrosion Environment – Generalizations:

• Moist air is more corrosive than dry air.
• Corrosion rate increase as temperature increases.
• Corrosion rate depends on specifics present – Chlorides.
• Polluted air is more corrosive than fresh water.
• Salt water is more corrosive than fresh water.
• No corrosion will occur in a vacuum.