Effects of pH on Electrochemical Properties of 316L Stainless Steel

The electrochemical behaviors of 316L stainless steel in H2SO4 and NaOH solutions were discussed by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and Mott-Schottky curves. The results show that 316L stainless steel has a wide passive anodic region in the two solutions. EIS results indicat that the impedance value of the passive film in NaOH solution was higher than that in H2SO4 solution. Dynamic electrochemical impedance spectroscopy results demonstrate that variation trends of the EIS with the increase of potential in the two solutions were different. Mott-Schottky results show that the passive films of 316L stainless steel in H2SO4 solution and NaOH solution were all composed of p-type and n-type oxides.