Effect of Water on the Stress Corrosion Cracking Behavior of API 5L-X52 Steel in E95 Blend

摘要

The effect of water content (0.5%, 1%, 2%, 5%, 10% y 20 V%) in E95 blend (5 V% gasoline 95 V%ethanol) on the stress corrosion cracking (SCC) susceptibility of X-52 carbon steel was investigated.Slow strain rate tests (SSRT) coupled with electrochemical noise measurements (ECN) were carried-6 -1 out using a strain rate of 1 X 10 s . In general, scanning electron microscopy (SEM) observations onfracture surfaces showed a ductile behavior. However, secondary cracking was only observed forspecimens exposed to solution containing up to 2 V% water. ECN gave indication of a likely localizedcorrosion process occurring at low water concentrations, whereas for water content above 2 V%, auniform corrosion process seems more likely to occur. In addition, the material response immersedinto the various solutions was investigated by using linear polarization resistance (LPR) measurements,weight loss and pH measurements. Reasons to explain the behavior found are discussed.