2.6. Potentiodynamic polarization studies
A bio-anatytical (Model 100 A) computerized electrochemical
analyser was used to perform potentiodynamic
polarization studies. The various corrosion kinetic parameters,
such as corrosion potential (Eeoc), cathodic and anodic
exchange-current densities (io.c and io,a) , cathodic and anodic
Tafel slopes (b~ and ba) , were derived from the resulting
polarization curves.
The working electrode was a rectangular strip with an
exposed surface area of 1 cm 2. Platinum foil of larger area
and a Hg/HgO/10 M NaOH system served as the counter
and reference electrodes, respectively [ 6]. The polarization
was carried out at a scanning rate of 10 mV/s. All experiments
were undertaken at a temperature of 30 _ 1 °C.