Preparation And Performance Of Electronic Anti-corrosion Coated Titanium Anode

At present, metal tank of water heater on the market commonly be protected bysacrificial magnesium anode. There are some deafcts exsist in sacrificial magnesium anodeprotection such as short life, water pollution, consumption of metal, the protection of thewater heater is not adjustable, etc. Therefore, study on the mixed metal oxide coated titaniumanode electronic anti-corrosion was carried out to meet the need of protection of water heatertank.According to the principle of cathodic protection, the subject applied impressed currentcathodic protection method to protect the water heater and metal oxide coated titanium anodewas used in impressed current cathodic protection system as an auxiliary electronic anodes.The main study includes preparation and performance testing of mixed metal oxides oftitanium anode, the study of electrochemical parameters of cathodic protection and electronicanti-corrosion protection design parameters and the study of corrosion protection effect ofelectronic anti-corrosion protection to carbon steel and stainless steel tank.The Ru-Ir-Ti and Ru-Ir-Sn-Ti coated titanium anode was prepared by thermaldecomposition method, the performance of them were studied by SEM, XRD, polarizationcurves, and strengthen electrolytic life. It is found that the appropriate amount of Sn groupadded in the Ru-Ir-Ti coatings can improve the electrode performance and the coatingshowed the best electrochemical performance with10%molar content of Sn and thestrengthen electrolytic life is long to3times of sodium hypochlorite generator standards with30%molar content of Sn.The study of cathodic protection electrochemical parameters and the electronicanti-corrosion protection parameters shows that for steel materials, the minimum protectionpotential is-0.53V and hydrogen evolution potential is-1.15V. In order to protect materialscompletely, the protect potential should be controlled in-0.53V to1.15V and the middlepotential value-700mV to-900mV is the optimal potential. Polarization potential and the cellvoltage follow a linear relationship. The polarization potential and temperature, ratio ofelectronic anode surface area and protected materials surface area and the conductivity of theaqueous medium follow a positive correlation. The cathodic polarization potential is between -700mV～-900mV when the bath voltage is2.5V and the ratio of electronic anode surfacearea and protected materials surface area ratio is1:25. The polarization current andtemperature follow a linear relationship roughly. It meets the needs of the cathode materialpolarization at different temperatures.The result of protective effect of carbon steel by electronic anti-corrosion protectionshow that the results of the electronic anti-corrosion parameters determined by experimentare reliable and the protective effect is significant if select the appropriate protectionparameters. The result of constant cell voltage control electronic corrosion protection showthat the polarization voltage of stainless steel tank is corresponding with the experimentalresults of cathodic protection design parameters and keep long term stable during the testing,so that the water heater is in a good state of protection.