Effects of Ethanol Chemistry on the Stress Corrosion Cracking and Passivation Characteristics of X65 Pipeline Steel in Ethanol Fuel Environments

摘要

The demand for renewable alternative fuels has led to an increase in production of fuel gradernethanol (FGE), which in turn necessitates development of an efficient mode of transportation forrnthis fuel. Pipelines, made of carbon steel, are being explored for compatibility with FGE.rnOccurrences of stress corrosion cracking (SCC) of carbon steels in FGE have spurred studies onrnthe mechanism of this corrosion phenomenon, and have shown that water, chloride ions,rndissolved oxygen, and acidity are all major factors in the promotion of SCC of pipeline steel. Inrnthis study, passivation kinetics and corrosion behavior of X65 pipeline steel as a function ofrncompositional variations in FGE environments are investigated. Effects of changes in waterrncontent and pH of FGE (pHe) on the electrochemical characteristics of steel in FGErnenvironments are reported. Changes in crack mode and severity induced by introduction of ppmrnlevels of dissolved chloride ions are also evaluated.