CHEMICAL-COMPOSITION OF PASSIVE FILMS ON AISI-304 STAINLESS-STEEL

Chemical characterization of passive films formed on AISI 504 austenit ic stainless steel, in a borate/boric acid solution at pH 9.2, under v arious conditions of potential, temperature, and polarization time, wa s made by Auger electron spectroscopy combined with ion sputtering, an d x-ray photoelectron spectroscopy (XPS). The depth chemical compositi on, thickness, and duplex character of the passive layers were determi ned after processing AES sputter profiles by our quantitative approach based on the sequential layer sputtering model. Moreover, separated c ontributions of elements in their oxidized and unoxidized state could be disclosed from part to part of the oxide-alloy interface. The XPS s tudy specified the chemical bondings which take place inside the film, between Fe and oxygen (and water).