| Abstrakt: |
The hydrodynamic conditions and fluid flow are important factors that affect the corrosion of metals. They also influence the inhibition performance of different corrosion inhibitors. In this paper, the corrosion behavior of St52-3 rotating disc electrode, RDE, in NaCl solution containing ZnSO4 salt, as a cathodic inorganic corrosion inhibitor, has been studied under different hydrodynamic conditions. Two electrochemical methods, including potentiodynamic polarization and electrochemical impedance spectroscopy, have been used. The effects of solution hydrodynamic on the open Circuit potential, polarization curves and electrochemical impedance diagrams of the steel RDE in blank NaCl solution as well as in the solution containing ZnSO4 have been considered. It has been shown that ZnSO4 inhibits the corrosion of steel in NaCl solution. By increasing the rotational speed, in the absence and presence of inhibitor, the corrosion current density increased and charge transfer resistance decreased. ZnSO4 had relatively low efficiency in stagnant conditions but its influence improved significantly under hydrodynamic conditions. It was mainly attributed to an increase in Zn2+ ions mass transport towards electrode surface, which leads to the formation of more protective films and therefore, enhances the protection against corrosion. [ABSTRACT FROM AUTHOR] |
