Double layers of nickel and aluminum are electroplated on a 316L stainless steel (316L SS) plate, which is routinely used as a separator in molten carbonate fuel cell (MCFC) stacks, and then heat-treated at 650 or 800 o C for 1h. This results in the respective formation of a surface layer of Ni 2 Al 3 or NiAl intermetallic compound, which are known to be highly corrosion-resistant in molten carbonate electrolyte. The corrosion behaviour of each plate in a molten electrolyte of (Li 0 . 6 2 K 0 . 3 8 ) 2 CO 3 or (Li 0 . 5 2 Na 0 . 4 8 ) 2 CO 3 is evaluated through immersion tests and polarisation measurements. The surface layer of Ni 2 Al 3 or NiAl maintains good adhesion to the stainless steel substrate and no corrosion product is detected in any of the plates with a surface layer after immersion tests. Polarisation measurements reveal that, regardless of experimental conditions, the corrosion potentials of the plates with a surface layer shift to more positive values and the passive currents are lower than that for a bare SS plate. The corrosion rate of the NiAl surface layer is slightly lower than that of Ni 2 Al 3 .