Passivity of 316L stainless steel in borate buffer solution studied by Mott-Schottky analysis, atomic absorption spectrometry and X-ray photoelectron spectroscopy

The passivity of 316L stainless steel in borate buffer solution has been investigated by Mott-Schottky, atomic absorption spectrometry (AAS) and X-ray photoelectron spectroscopy (XPS). The results indicate that the polarization curve in the passive region possesses several turning potentials (0 V-SCE, 0.2 V-SCE, 0.4 V-SCE, 0.6 V-SCE and 0.85 V-SCE). The passive films formed at turning potentials perform different electrochemical and semiconductor properties. Further, the compositions of the passive films formed at turning potentials are investigated. The results reasonably explain why these potentials appear in the passive region and why specimens perform different properties at turning potentials. (C) 2010 Elsevier Ltd. All rights reserved.