Raman Spectroscopy of Passive Films Formed on Metal Surfaces in Corrosive Environments.

摘要

In situ Raman spectra were obtained of passive films formed on metallic lead surfaces under freely corroding conditions in dilute hydrochloric acid and sodium hydroxide solutions. The spectra identified the coating formed in HCl solution as PbCl2 and that formed in NaOH solution as PbO. Passive film Composition was the same in solutions containing dissolved oxygen as in deoxygenated solutions but the rate of film growth was much greater in the presence of oxygen. Spectra of the films immersed in solution were virtually identical to those of the same films in air. The experimental program for passive films on lead was successfully completed. Investigations on passive films on iron surfaces were initiated. (Author)