Effect of moisture contents of bentonitic clay on the corrosion behavior of steel pipelines

Abstract Bentonite is a very important naturally occurring clay and it is used in many great commercial processes. Somehow it is sustained next to the mild steel in many industrial uses. The monitoring of corrosion of mild steel in different moisture contents is very important to avoid deterioration of metal surface of drilling equipment and pipelines. The electrochemical behaviors of mild steel in bentonite were investigated for a series of moisture content. The open circuit potential and potentiodynamic polarization curves proved that the corrosion rate is directly proportional to the moisture content till 40%. The corrosion rate is approximately constant in spite of increase of moisture content more than 40%. The weight loss measurements also proved that there was the same trend of mild steel in bentonite at different moisture contents. The mode of action of bentonite is considered, so the used sample was investigated according to engineering, mineralogical and chemical behaviors by X-ray diffraction, X-ray fluorescence, particle size distribution, natural moisture content, Atterberg limits and swelling shrinkage characteristics.