Pitting Corrosion of Carbon Steel in Fuel Grade Ethanolic Environment

Bioethanol is one of the major renewable biofuel considered as alternative energy source in transportation applications. However, there are some corrosion concerns related to the possible organic and inorganic contaminants in the fuel grade ethanol (FGE). One such possible corrosion concern is susceptibility of carbon steel to localized corrosion in chloride containing FGE. In this study, pitting of carbon steel was studied in chloride containing environment using immerse test as well as using electrochemical methods. Effects of chloride concentration, water, acidity, oxygen level on pit initiation and growth were evaluated. Detailed mechanisms of pitting corrosion, such as role of passivation, passive layer breakdown and inclusion effects were disclosed by electrochemical polarization, impedance measurement and surface analysis.