Abstract
A potentiostatic polarization method is used to evaluate the corrosion behavior of SS316L in simulated
anode and cathode environments of polymer electrolyte fuel cells. A passive barrier oxide film is observed
to form and reach steady state withinw10 h of polarization, after which time the total ion release rates are
low and nearly constant at w0.4 mg cm2 h1 for all potentials investigated. The equilibrium film thickness,
however, is a function of the applied potential. The main ionic species dissolved in the liquid are
predominately Fe followed by Ni, that account for >90% of the steady-state corrosion current. The
dissolution rate of Cr is low but increases systematically at potentials higher than 0.8 V. The experimental
ion release rates can be correlated with a point defect model using a single set of parameters over a broad
range of potentials (0.2e1 V) on the cathode side. The interfacial contact resistance measured after 48 h of
polarization is observed to increase with increase in applied potential and can be empirically correlated
with applied load and oxide film thickness. The oxide film is substantially thicker at 1.5 V possibly because
of alteration in film composition to Fe-rich as indicated by XPS data.
