The effect of partial replacement of nickel with nitrogen on the mechanism of localized corrosion resistance and repassivation for nitrogen-bearing stainless steel was investigated using anodic potentiodynamic polarization technique. The solutions used for this study contained 0.0, 0.05 and 0.33 M Fe 3+ for solutions I, II and III, respectively, in a total Cl À ion concentration 1 M. The pitting attack was found to be retarded by nitrogen addition and the samples were able to passivate as the nitrogen increase. Addition of nitrogen allows the decrease in the wt.% of Ni, but to a certain limit. Nitrogen is adsorbed on the interface of the metal oxide and results in the repulsion of Cl À ions. Moreover, it reacts with H + ions in the solution leading to higher pH, which explains the retardation effect of nitrogen to corrosion. D

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The kinetics of interaction of benzotriazole (BTAH) with the surface of copper were studied using an electrochemical quartz crystal microbalance (EQMB) and electrochemical impedance spectroscopy (EIS). Upon injecting BTAH into the electrolyte, three regions appear in the time response of the microbalance. Region I (at short time scale of few minutes) exhibits rapid linear growth of mass with time. This is attributed to the formation of a Cu(I)BTA film that is several hundred layers thick. Region II reveals adsorption of BTAH at a slower rate, on the inner Cu(I)BTA complex. Region III is a plateau indicating that the BTAH film attains an equilibrium thickness, which increases with the concentration of BTAH. The polarization resistance of the interface changes with time in a similar fashion while the double layer capacitance decreases. The results suggest that the thickness of the physically adsorbed film of BTAH increases with time and BTAH concentration while the thickness of the inner Cu(I)BTA remains constant. Two semicircles were obtained in the impedance spectra corresponding to the complex Cu(I)BTA and the physically adsorbed BTAH.

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