Thermal nitridation of chromium electroplated AISI316L stainless steel for polymer electrolyte membrane fuel cell bipolar plate

The electrical and corrosion properties of surface-nitrided AISI316L stainless steel are evaluated to assess the potential use of this material as a bipolar plate for a polymer electrolyte membrane fuel cell. Chromium is electroplated on the surface of the AISI316L stainless steel before nitridation. The nitriding condition is selected so as to form Cr2N nitride only and the result is compared with that of a CrN + Cr2N nitride coating. The stainless steels with the Cr2N nitride protective coating layer exhibit better interfacial contact resistance and corrosion resistance than the as-rolled or (CrN + Cr2N)-coated AISI316L stainless steels.