3.1. Potentiodynamic polarization method

The potentiodynamic polarization curves were recorded using a potentiostat PGZ101. The electrochemical measurements were performed in a conventional three electrodes electrochemical cell: Consisting of platinum electrode as Auxiliary electrode, saturated calomel electrode (SCE) as the reference and Brass alloy as the working electrode the form of a disc of the surface 0,78cm², the scanning speed of 1 mV/s, starting from the free potential of corrosion and moving in the cathode range towards more negative potentials until a surge of -1 V/Ag–AgCl and in the anodic domain by moving towards more and more positive potentials up to an overvoltage of 0.4 V/Ag–AgCl.

Before each measurement, the sample was polished with different grad abrasive paper (600; 1000; 1200), cleaned with acetone, washed with double distilled water and finally dried with hot air. These curves were obtained after one hour of immersion in the electrolytic solution with corrosion potential (Ecorr). Then the cathodic and anodic curves were recorded using independent plots.