(Invited) Passivity and Localized Corrosion of Stainless Steels in Energy-Related Applications

Abstract

In recent years, new types of environments related to energy technologies can provide new challenges for the passivity of traditional materials. Examples are different types of biofuels (ethanol, ethanol-gasoline blends, biodiesel). For instance, stress-corrosion cracking of steels can take place in ethanolic environments and Al alloys can show very fast degradation in ethanol-containing fuels at higher temperatures. This presentation will focus on passivity and localized corrosion of stainless steels in such new type of environments. Critical factors of localized corrosion were studied in different ethanol-gasoline blends, in presence of various corrosion-enhancing factors (such as H2O, chloride contamination). The influence of the different factors on occurrence of pitting corrosion and the morphology of growing pits was studied. In addition, XPS measurements were carried out, to explore the effect of the specific environment on the nature of the passive films. Other examples of the behavior of stainless steels in energy-related applications will be shortly discussed, such as passivity and localized corrosion in molten salts that can be used as heat transfer media in high temperarature applications.