Thirty-Eight Years of Atmospheric Corrosivity Monitoring

The marine atmospheric test site at Kure Beach, North Carolina, has long been recognized for its corrosion severity. It represents a benchmark for testing materials' resistance to marine atmospheric corrosion. The two test areas at the site have often been referred to as the 80-foot and 800-foot test lots (or the 25-meter and 250-meter lots), respectively. For over 38 years the amount of airborne chlorides from the sea spray have been monitored monthly. Chloride deposition is only one of several environmental factors which can contribute to atmospheric corrosion. Some of the other important factors include relative humidity, time of wetness, temperature, prevailing wind direction, and rainfall—which are all also monitored routinely. Corrosivity is monitored more directly by determination of mass loss for two reference materials, carbon steel and zinc.

Because of a number of recent changes, the 25- and 250-meter test locations have now been designated as the “oceanfront” and the “near-ocean” lots. Continued monitoring of these sites will benefit existing and future marine atmospheric test programs, including those of various ASTM subcommittees. Examples of materials on continuous exposure in the “museum areas” of the oceanfront and the near-ocean lots are reviewed for the purpose of educating new corrosion engineers on the importance of long-term testing in natural environments.