Atmospheric corrosion study in a harbor located in a tropical island

Abstract

Atmospheric corrosion level in tropical coastal zones is usually very significant. Corrosion control and preservation of infrastructure in these regions is very important to increase durability. Atmospheric corrosion of carbon steel, copper, galvanized steel, and aluminum was evaluated in a coastal industrial port zone located in a tropical island during 1 year. Samples were exposed at seven outdoor corrosion sites located at different distances from the sea. Main atmospheric pollutants, relative humidity, and air temperature were monitored during the exposure time. The existence of a combination between two of the most aggressive atmosphere types was determined (coastal‐industrial and industrial‐coastal). Changes in RH and temperature influenced significantly the chloride deposition. A new statistical model to explain the influence of time of exposure for all metals tested was developed. A possible antagonist effect between pollutants on corrosion may be possible. Acceleration of corrosion rate vs time is observed in the site close to the shoreline. Significant differences between corrosivity categories determined and those calculated by ISO standard dose response functions were found. The narrow entrance of the harbor with low movement of the inner water causes a decrease in salinity in the port zone.