Influences of plastic strain and strain rate on corrosion behavior of 316L stainless steel in simulated cathodic environment of proton exchange membrane fuel cell

The influences of the plastic strain and strain rate on the corrosion behaviours of 316L stainless steel (316L SS) in a simulated cathodic environment of proton exchange membrane fuel cells (PEMFCs) are investigated using potentiodynamic curves, electrochemical impedance spectroscopy (EIS), Mott-Schottky plots and X-ray photoelectron spectroscopy (XPS). The results demonstrate that 316L SS is in the passive state in the simulated cathodic environment of PEMFCs and that a passive film can be formed on the cathodic bipolar plate, which is composed of 316L SS, during PEMFC operation. The passive film can protect 316L SS from further corrosion, and the corrosion resistance of the passive film on 316L SS reaches a maximum at a plastic strain of 20%. The corrosion resistance increases with the strain rate; thus, the maximal corrosion resistance corresponds to a plastic strain of 20%, and the corrosion protection increases with the strain rate. The XPS results demonstrate that the Cr2O3 content in the passive film on 316L stainless steel reaches a maximum at a plastic strain of 20%, and the increased strain rate can increase the Cr2O3 content.