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.