Corrosion control by voltage scanning technique at potential of zero charge

Abstract

Corrosion protection at potential of zero charge, Epzc, technique is an effective method to control corrosion with low cost and more environmental friendly. Previously, cathodic protection is used to control corrosion but it consumes more current and potential zero charge method is studied to replace it. Epzc is a new method using small current to mutually neutralize the positive and negative charges electric double layer on metal-solution interface. This method reduces the electric current that need to supply in order to protect steel from corrosion damage. Potentiostat is used to determine voltage scanning and current density in 3.5 wt % of sodium chloride. In this research open circuit potential and Tafel was plotted to identify corrosion potential, Ecorr, and corrosion current density, Icorr, value of mild steel. Identification of PZC current supply, magnitude of voltage scanning towards Ecorr and voltage scan rate for -1 to 0mV was conducted as an experiment to prove it. Overall, it is proven that oxidation reaction was not take place at Epzc. Magnesium as a reactive metal also was tested under Epzc for 168 hours shows the positive result whereby at Epzc, the magnesium takes longer time to be corroded.