Corrosion Engineering Laboratory, Department of Petrochemical Engineering, Basra Engineering Technical College, Southern Technical University Basra / Iraq
Abstract
Storage tanks made from mild steel are always subject to corrosion when the conditions are permitting. Industrial water storage tanks located in Al-Shaiba, Basra, Iraq are suffering from severe corrosion, and research on the mitigation of this problem is underway. In this study, Nitrogen, Phosphorus and Potassium (NPK) fertilizer was added to the water stored in such tanks to study its effect as corrosion inhibitor. The material of the selected tank’s wall is mild steel (0.18% C). NPK fertilizer was prepared as electrolyte solution at different concentrations (0.1, 0.2, 1 and 2 g/l), and the study was conducted at 25 °C. The corrosion rate and the penetration rate of the mild steel are measured by electrochemical measurements.
The study showed that mild steel possesses a good resistance to corrosion at 0.2 g/l of the NPK inhibitor, in comparison to other concentrations of NPK. Above this concentration, the resistance to corrosion was found to be decreasing. This inhibitor could be recommended as good, cheap, and non-toxic material used to decrease the risk of corrosion in industrial processes.