Umudike Journal of Engineering and Technology

Enormous funds are spent on the protection of engineering components annually as a result of corrosion. Degradation can set in, due to electrochemical reaction that takes place between materials and the environment leading to reduced performance. The associated downtime caused by replacement and maintenance of vessels and other equipment necessitated seeking for techniques and method to efficiently combat corrosion. This study evaluated the corrosion behaviour of brass, Coated Mild Steel (CMS) and Stainless Steel (SS) in sodium hydroxide (NaOH). Three samples (1 x 30 x 30 mm³) each were used for Potentiostatic Polarization Experiment (PPE). The samples were cleaned, and soaked in 1M NaOH solution. Open circuit potentials and current densities of the samples were obtained from PPE which were used to evaluate their corrosion rates. The pH of the media was recorded before and after each experiment. The results obtained using PPE in NaOH (in mm/y) were 0.057, 0.102 and 0.071; for brass, CMS and SS respectively. The pH of the medium was measured as 10.9.The results revealed that brass has least corrosion rate in Sodium Hydroxide. The highest corrosion rate was obtained for CMS. It can be concluded that brass and SS had very low corrosion rates in Sodium Hydroxide using PPE method.