Atmospheric Corrosion Behavior of Carbon Steel and Galvanized Steel after Exposure in Eretan and Ciwaringin, West Java']Java Province, Indonesia

The investigation of corrosion for carbon steel and galvanized steel has been conducted in the marine atmosphere of Eretan and Ciwaringin Districts, West Java Province. The exposure time of the field test was up to 200 days, and their corrosion rates are determined according to the weight loss method. The objective of the work is to elucidate the corrosion behavior of those alloys, which is affected by distances from the coastline and environmental conditions. The magnitude of the corrosion rate for carbon steel was 20 times as high as that for galvanized steel in both districts. The distance from coastline has significantly affected the magnitude of corrosion rate, where that both alloys in Ciwaringin are lower than that in Eretan. The deposition of chloride ion in Eretan and Ciwaringin Districts were 4.305 mg/m(2) day and 1.863 mg/m(2) day, respectively, where the higher chloride ion can tend to increase the corrosion rates. Relative humidity (RH), which is over 60%, has an essential role in the corrosion process as well as rainfall. The uniform corrosion attack was observed both alloys after exposure. The corrosion product phases of galvanized steel exhibit zincite, hydrozincite, and simonkolleite as the typical coastline atmosphere phases in Eretan, but not in Ciwaringin. The formation of rust product for both metals lead the decrease of further corrosion attack due to the barrier between metal and environment. The usage of galvanized steel is remarkable to minimize corrosion attack compared to that of carbon steel in the tropical coastline.