Effect of Tropical Atmosphere on Corrosion of Different Metals

Abstract

Atmospheric corrosion is clearly the most noticeable of all corrosion processes. A tremendous amount ofeconomic losses are caused by atmospheric corrosion. Thus, it is imperative to know the level of atmosphere’saggressiveness or in other words “corrosivity”, before designing or planning any corrosion prevention strategy. In Singapore, corrosivity values were not recorded earlier though the process of measurement and recordingwas prevalent in other countries. With an aim of filling this gap, three test sites were setup at three locationsin Singapore to represent marine, industrial and urban atmospheres or their mixtures. Subsequently, corrosivityreadings were measured and recorded according to ISO 9223:2012 for the first time in Singapore. Salientatmospheric constituents or parameters like time of wetness (TOW), Cl-, SO2, NO2, O3, and HNO3 weremeasured at all sites over a period of time to categorize corrosivity of particular atmosphere. The effectof the atmosphere on corrosion of steel, Cu, Al, and Zn has also been investigated and quantified. “Estimated”and “determined” corrosivities were quantified and compared according to ISO 9223 standard. The studydata along with final corrosivity measurements will be presented and discussed in the present work.