Study On Inhibitors And Corrsion Behaviors Of L360 Steel In Vapor And Liquid Phases Containing H₂S/CO₂

The corrosion process of L360 steel in vapor and liquid phases containing H2S/CO2 was studied by dynamic weight loss method in this paper, the influence of temperature and pressure on corrosion is like this: in condition of H2S pressure was 1.6MPa, CO2 pressure was 1MPa, the temperature was 30～40℃, the corrosion rate of vapor phase was larger than the liquid phase, as the temperature rised to 50～60℃, the distance became small; when the temperature was 60℃, as the pressure of H2S,CO2 increases, the corrosion rate of vapor and liquid phases both increase; in condition of H2S pressure was 1.6MPa, CO2 pressure was 1MPa, the temperature was 40℃, the corrosion rate was basic same in H2S/CO2 systerm and H2S systerm, Analysis of the protective film layer on surface of L360 steel showed that the product was FeS.One type of quatemary ammonium salts inhibitor was synthetized in this paper, with the formulation of several chosen Gemini surfactants, several high effective inhibitors were obtained. To compare with the foreign inhibitors, the inhibition efficiency was studied by dynamic weight loss method, the results revealed that in experiment conditions, the quaternary ammonium salts performance well with the inhibition efficiency of 89%, and the inhibition efficiency of formulated inhibitor is 92%,which is equivalent to or beyond that of foreign inhibitor CI1204.The mechanism of corrosion inhibitor was studied by potentiody-namic polarization curves, electrochemical impedance spectroscopy, and X-ray diffraction. Analysis of the protective film layer on surface of L360 steel showed that the dense layer might be troilite. The function of inhibitors might let the layers dense.