Effect of Temperature on Corrosion Resistance of Three Kinds of Coatings Containing Defects

In 3.5% NaCl solution saturated with CO2 gas,the corrosion resistance of three kinds of coatings with defects was researched and analyzed by electrochemical polarization curves,electrochemical impendance spectroscopy (EIS) and SEM.The results showed that the surface of three kinds of coatings containing defects was flat and even,the order of their thickness from big to small was coating C,A and B.But the coatings A and B were relatively uniform.After electrochemical test,the damage of coating B was the most serious,coating C was the lightest,and coating A was between coating B and C.The results of EIS showed that the corrosion resistance of the coatings was corresponding to the thickness at lower temperature,the corrosion resistance was corresponding to the thickness uniformity at higher temperature.