Using EIS To Study The Corrosion Failure Behaviors Of High-temperature Coating

According to the system of Halfaya oilfield that high salinity,high H₂S, CO₂ and corrosion properties of high temperature,there are EIS?SEM and FTIR methods to test different phenol aldehyde-epoxy coatings by simulating the corrosive environment.It can analysis experimental data and get the result of the advantages and disadvantages about four kinds of coating,then gives the reasonable inference of the failure mechanism of coating.Through the modified SiO₂,we can modify the Titanium urushiol coating,and get the best formula of the coating by single factor experiment method. The main research contents are as follows:1.There are some experiments about phenol aldehyde-epoxy coatings at different temperatures under high salinity test.According to the electrochemical impedance,SEM and other data, we can get the advantages and disadvantages of the coatings.The order of the coating at protective performance is A1>D1>C1>B1.2.According to the corrosion behavior of four kinds of phenol aldehyde-epoxy coatings, and to compare with the date of FTIR,as the result that the characteristic peaks of the keys of CH with benzene,phenol hydroxyl have big changes.It shows that the protective performance of coatings have reducd,because the polymer chains have broke.3 .According to the performance of the coating under different temperature, it is concluded that the protective performance of coatings decline with the ascension of temperature in the experimental condition of this experiment ,but there is not a linear relationship with it.4. Through the single factor experiment method, it is concluded that the range of the best formula of the coating of SiO₂:5.6 to 6.1 %.After modification, the mechanical properties of the coating have bacome more excellent.According to the EIS,SEM and other data,it is obvious that the corrosion resistance and applicability of modified coating are better.