The Effect of TiO2 on Corrosion Resistance of Porcelain Enamels in Sour Water: A Feasibility Study for Application in Oil Pipes and Container

Porcelain enamels are widely used as coating on metals and alloys, because of their excellent corrosion resistance against different aggressive media with different pHs at high temperatures up to 600oC. In this regard, the chemical composition of the enamels is very important and TiO2 is introduced as additive to promote the corrosion resistance of the enamels. Therefore, corrosion resistance of TiO2 containing and TiO2 free enamels has been examined by applying standard test method ISO 2742. This test has been done in simulated sour water that is one of the most corrosive solutions which is produced during oil refining in refineries. The test has been performed three times on samples for 2.5h. Then, the attacked surfaces were studied by Scanning Electron Microscope (SEM) and then elemental distribution of surface was investigated by Energy Dispersive Spectroscopy (EDS). Finally, by applying Electrochemical Impedance Spectroscopy (EIS), Nyquist spectra of the samples were obtained and compared. The results showed that adding 3.20%wt TiO2 considerably enhanced the chemical and corrosion resistance of the enamel.