Influence of atmospheric pollution on corrosion of materials in Saudi Arabia

Research has been carried out for 7 years in eight marine atmospheres with annual average chloride deposition rates of 63-704 mg Cl-/m(2) day and sulphur dioxide deposition rates of 6.851-10.887 mg SO2/m(2) day. A study of environmental parameters: temperature, relative humidity, airborne chloride and SO2 on the site have been accomplished. Apart from this, the paper also considers the corrosion rates of carbon steel, stainless steel (AISI 304) and galvanised steel and the resulting corrosion products and layers, and their dependence of atmospheric salinity of the site. X-ray diffraction analyses were carried out in order to understand the lepidocrocite and goethite, high akaganeite and magnetite contents of corrosion products. Corrosion rates were determined by weight loss. The aggressive classification was made as per the ISO 9223. Moreover, a technique for calculation of coefficients in the power-linear function for long-term prediction of metal corrosion losses of exposed metals and alloy are presented.