Outdoor and indoor atmospheric corrosion of non-ferrous metals

In the present paper, a study of the atmospheric corrosion of copper, zinc and aluminium exposed on three test sites indoors and outdoors (coastal, urban-industrial and rural) under different exposure conditions up to 18 months is reported. Corrosion results are treated statistically and adjusted to a model previously proposed for steel [A.R. Mendoza, F. Corvo, Corrosion Science 41(1) (1999) 75-86.] based on the influence of environmental parameters and main pollutants (SO2 and chlorides) on the atmospheric corrosion of metals. The interaction between the chloride deposition rate with the time of rainfall (outdoors) and with the time of wetness at temperature between 5 degrees C and 25 degrees C (indoors) were found to be the most significant variables influencing the corrosion of the three metals investigated; although other variables appeared to be important in the corrosion process depending on the metal nature. The results obtained confirm and allow us to expand the model previously proposed for steel to non-ferrous metals. A classification of the atmospheric corrosion aggressivity of the test sites based both on environmental data and corrosion rate measurements was made according to ISO 9223. The corrosion aggressivity prognostic of this standard is not always in agreement with the results obtained in Cuban atmospheric conditions. (C) 2000 Elsevier Science Ltd. All rights reserved.