Atmospheric corrosion of carbon steel under field exposure in the southern part of Vietnam

The corrosion behavior of carbon steel with and without shelter at four test sites (four cities) in the south of Vietnam was investigated in terms of the environmental factors such as average relative humidity, rainfall, sulphur dioxide and chloride depositions, and various exposure periods. The mass losses of the specimens with shelter at four test sites were related to SO2 concentration at each site. Without shelter, the mass loss at HoChiMinh was lower than that with shelter, whereas those of the other sites were higher without shelter than with shelter. Although the corrosion behavior at HoChiMinh was difficult to explain based on the environmental factors, it was estimated from a protective corrosion products caused by a synergistic effect among SO2 concentration, rain and sunlight.