Corrosion behavior of oxide films on AISI 316L SS formed in high temperature water with simultaneous injection of zinc and aluminum

Oxide films were formed on AISI 316L SS in high temperature water of 553.15 K with simultaneous injection of zinc and aluminum (S (zinc + aluminum)) and with injection of zinc (S (zinc)), respectively. Corrosion behaviors of the oxide films were studied by electrochemical potentiodynamic polarization, scanning electron microscope (SEM), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS) and photocurrent measurement. Compared with that of the oxide films on S (zinc), the polarization plot of the oxide films formed on S (zinc + aluminum) showed lower corrosion current density. And the EIS results indicated that the resistance of the oxide films on S (zinc + aluminum) was much larger than that of the oxide films on S (zinc). Meanwhile, the SEM images presented that more protectively compact oxide film was formed on S (zinc + aluminum). The XPS results indicated that zinc element was detected on the surface of S (zinc), while both zinc and aluminum elements were detected on the surface of S (zinc + aluminum). Moreover, the photoelectrochemical response results suggested that compared with that of the oxide films on S (zinc), additional phases alpha-FeOOH and ZnAl2O4 were contained in the oxide films on S (zinc + aluminum). The solubility of ZnAl2O4 in water was calculated. (C) 2017 Elsevier B.V. All rights reserved.