The main purpose of this study is to develop a method to characterize and classify the atmospheric corrosivity of the Sao Luis City, located at the Brazilian North coast, establishing 15 atmospheric corrosion sites (ACS), in different environments. These sites were monitored on a monthly basis to determine the deposition rates of atmospheric contaminants, such as airborne salinity, represented by chloride ions (Cl_), sulfur-containing substances, represented by SO2 and dustfall. These parameters were correlated to meteorological data and both were used to classify the atmospheric corrosivity. At the same time, metallic samples such as low carbon steel, galvanized steel, aluminum and copper, which are commonly used in transmission and distribution power lines, were exposed to the environment in four of these 15 sites, in order to qualify the environmental aggressiveness according to the corrosion rate of these materials. Based on the mapping results, it was possible to determine the materials which are more proper to be used in those specific areas, which could result in the cost reduction due to a span-life extension of such structures.
atmospheric corrosion; metals degradation; corrosion mapping
