Abstract
In the present study the characteristics of measured electrochemical noise (EN) influenced by different modes of electrolyte movement were studied. The measurements were performed in a still solution, as well as in movement of electrolyte: stirring, and laminar flow with different velocity. Electrolytes with different corrosivity were used. In order to relate measured EN to the development of corrosion processes, digitized images of the electrodes were recorded continuously during these measurements. After the tests were finished, the corroded electrode surfaces were examined also by the scanning electron microscope. In order to assess the general electrochemical characteristics of the investigated corrosion systems, the electrochemical impedance spectroscopy and the potentiodynamic polarization technique were used. It was found that the characteristics of EN, in general, change significantly with strong movement of the electrolyte. The results showed that the main source for this change is an enhancement or transformation of corrosion processes. It was indicated from the recorded digitized images that the low-frequency part of EN signals is generated by temporal non-equilibrium between the electrodes.
