STUDY OF STRUCTURE OF PHOSPHATE FILM ON CARBON STEEL

A phosphate protective film was prepared on carbon steel. The structure of the film was analyzed with X-ray photoelectron spectra (XPS) and atomic is force microscope (AFM). AFM observed the full process of film formation clearly. XPS with rotation etch displayed multilayer structure of nanometer phosphate film. During film formation, small insoluble particles (ZnCa2(PO4)2) deposit on the carbon steel surface and grew up gradually, until cover the surface entirely.