Study On PPS-SiO₂ Superamiphiphobic Coating Preparation On X80 Steel And Corrosion Resistance

As the mainstream pipeline steel,X80 steel has an significant role in the oil and gas transportation industry.With the increase of service life span,its corrosion problem is increasingly serious.Due to their excellent hydrophobic and oleophobic properties,corrosion resistance and drag reduction propertie,superamiphiphobic materials have booming market application.In this paper,X80 steel was used as the main experimental material to study its electrochemical corrosion behavior,and PPS-SiO2 superamiphiphobic coating was prepared on it.Firstly,the electrochemical behavior of X80 steel in three corrosive media was studied by electrochemical method,the electrochemical impedance spectrum and polarization curve of X80 steel were obtained,and the corrosion products were analyzed.The results showed that 3.5%NaCl solution was the most corrosive to the samples.EDS,XRD and other characterization behaviors showed that the main electrochemical corrosion products were FeOOH,Fe2O3 and Fe3O4.Secondly,by means of substrate treatment,coating deposition and sintering,PPS-SiO2 superamiphiphobic coating was prepared on X80 steel surface,and the contact angle of water and ethylene glycol was measured.The electrochemical corrosion behavior of the coated samples was compared.The results show that the coatings deposited on the surface of X80 steel substrate after various treatment methods have certain properties of superhydrophobic and superhydrophobic.By comparing the electrochemical behavior coating and without,it is found that the electrochemical impedance and polarization impedance of the samples are significantly improved after coating,among which the corrosion resistance of the samples obtained by polishing,acid corrosion and coating is the most significant.The analysis showed that the surface of the samples coated with SiO2 reduced the conductivity of the samples and inhibited the electron escaped in the electrochemical corrosion process.At the same time,electrolysis and acid corrosion formed a protective layer on the surface,which further delayed the occurrence of corrosion and significantly improved the corrosion resistance of the sample.Finally,the wear resistance of the coating on 800#sandpaper and its durability in 3.5%NaCl solution were tested.The results showed that:in the wear resistance experiment,the contact angle of water and ethylene glycol decreased significantly when the sliding relative distance exceed 20cm of the untreated sample,and the relative sliding distance reached 60cm after the three treatment methods,it means that the three treatment methods could significantly improve the wear resistance of the sample coating.Coating in 3.5%NaCl solution immersion experiment showed that the treatment for coating samples soaked in 3.5%NaCl solution could keep superamiphiphobic ability more than 70 min,and untreated coating samples after soaking time more than 20 min,water,ethylene glycol contact angle were dropped to below 150 °,and decline rate to accelerate.In this paper,the electrochemical corrosion behavior of X80 steel was studied,and PPS-SiO2 coating was prepared.The three substrate treatment methods were evaluated,and some foundation work of the PPS-SiO2 superamiphiphobic coating has done,so as to have practical application value in corrosion resistance,scale prevention and drag reduction.