Role of Oxygen in Localized Corrosion and Stress Corrosion Cracking of Carbon Steel in Fuel Grade Ethanol

摘要

Stress corrosion cracking (SCC) of carbon steel has been observed in fuel grade ethanol (FGE). Electrochemical behavior of carbon steel and thus the role of localized corrosion in SCC has not been adequately studied due to the difficulty of performing electrochemical experiments in resistive environments such as FGE. A microelectrode technique was used in this work to conduct electrochemical studies in simulated FGE (SFGE). It was found that oxygen likely played multiple roles: it participated in the passive film formation in addition to its more commonly observed role in aqueous environments of changing the open circuit potential (OCP). A model, based on this dual role of oxygen, was proposed to explain the SCC mechanism of carbon steel in SFGE.