Papers by Author: Xian Long Cao

Abstract: There were little works about electrochemical corrosion behaviors that appeared in high H₂S and CO₂ containing environment. In this work, the electrochemical behaviors of tubular steel API-P110 in buffered acidic NaCl solutions saturated with high H₂S and CO₂ containing gases, were investigated by potentiodynamic sweep technique. Analysis of the results shows corrosion density declines with increasing CO₂ content in H₂S/CO₂. The corrosion potential of steel moves towards more negatively with the increase of CO₂ content in H₂S/CO₂. In pH 2.9 solution, Passivity appears in high H₂S and CO₂, but no passivity shows in due to decreasing in high H₂S. In pH 5.3 solution, cathodic liming density comes out and increases with the increasing CO₂ content in H₂S/CO₂, however, no cathodic liming density comes out in H₂S.

Abstract: This present work investigated the corrosion behavior of AZ31 magnesium alloy substrates pre-treated with bis-[triethoxysilylpropyl] tetrasulfide silane modified with cerium nitrate. The corrosion behavior of the pre-treated substrates in 0.005M sodium chloride solutions was assessed by potentiodynamic polarization, open circuit potential and electrochemical impedance spectroscopy (EIS). The results showed that the silane pre-treatments improved the corrosion resistance of the AZ31 magnesium alloy substrates in the presence of chloride ions. Especially the addition of cerium nitrate played an important role in reducing the corrosion activity.