Zinc–cobalt alloy plating (ZnCo) was successfully deposited on carbon steel (CS) applying current of
2 mA with galvanostatic technique. Polyaniline film (PANI) was synthesized with cyclic voltammetry
technique from 0.20 M aniline containing 0.20 M sodium tartrate solution on zinc–cobalt plated carbon
steel (CS/ZnCo) electrode. PANI film characterized by scanning electron microscopy (SEM), was covered
with a dark green-brown homopolymer film of strongly adherent homogeneous characteristic while the
other one was plated with a porous light ZnCo one. The corrosion behaviour of zinc–cobalt deposited
carbon steel electrodes with and without polyaniline (PANI) film in 3.5% NaCl solution was investigated
with AC impedance spectroscopy (EIS) technique and anodic polarization curves. The results showed that
PANI coating led to decrease of the permeability of metallic plating. The PANI homopolymer film provided
an effective barrier property on zinc–cobalt coating and a remarkable anodic protection to substrate for