Corrosion Resistance of Steel in Ethanol Containing Ionic Liquid Salts

Room temperature ionic liquids (RTIL) were found to be a kind of versatile lubricant with excellent friction-reduction, anti-wear performance. However, our knowledge is insufficient for understanding their corrosive properties. In the present work, the effects of the alkylimidazolium tetrafluoroborates and hexafluorophosphates on the corrosion properties of AISI 52100 (UNS G52986) carbon steels were studied using potentiodynamic scanning, electrochemical impedance spectroscopy (EIS), and electrochemical noise (EN). The results show that the carbon steel had a lower corrosion rate in 1-methy-3-hexylimidazolium hexafluorophosphates ethanol solution than in 1-methy-3-hexylimidazolium tetrafluoroborates ethanol solution. Comparing with the latter, the uniform corrosion process was the main process for the steel ball in the alkylimidazolium hexafluorophosphates ethanol solution. Using Gumbel distribution, the maximum corrosion charge of the steel in alkylimidazolium tetrafluoroborates ethanol solution was larger than that in alkylimidazolium hexafluorophosphates ethanol solution.