Atmospheric Corrosion of Metals in Urban Area

Abstract

Atmospheric corrosion rate depends on the content of the individual components in atmosphere, temperature of air,and  refers primarily on the moisture content, the content of the various particles and the SOx and NOx gases. Washing out the pollutants from the atmosphere creates strong acids, bases and salts that can corrode various metal and non – metallic structures. The analysis of certain precipitation parameters, analysis of metal and alloy samples exposed to the atmosphere in Sarajevo and Kiseljak, and analysis of metal and alloy samples without atmospheric influence were carried out. The methods used for sample analysis are linear voltammetry and cyclic voltammetry. An iron plate, chrome coated iron plate with worn out surface, zinc coated iron plate with worn out surface and brass plate were used as a samples. It was observed that the corrosion of samples in Sarajevo is more intensive as compared to the corrosion of samples tested in the area of Kiseljak. Linear voltammetry measurements in a given range of potentials gave more pronounced corrosion currents in the samples from urban area. Cyclic voltammetry measurements gave pronounced reduction peak at -0.25 V for brass, and for chrome coated iron plate at -0.05 V. For the zinc coated iron plate sample, potentials were shifted to negative values that are characteristics of   zinc pair. For chrome coated iron plate, reduction peak was detected at -0.75 V. The cyclic voltammogram for zinc coated iron plate with worn out surface is similar to the cyclic voltammogram for zinc coated iron plate. Urban area of Sarajevo is heavily polluted by different pollutants which can affect all aspects of life and environment. The occurrence of acid rains is intensified, which increases the corrosion of material of which the constructions are made.