Corrosion Mechanism Of Oil Water Tank And Optimization Of Anticorrosion Coating

Coating protection is the most effective and widely-applied anticorrosion way for storage tanks,In order to attain more effective anticorrosion effective for coating,this paper has analyzed components of corrosion outcomes of tanks through scanning electron microscope and made a judgment of corrosion types upon that.Meanwhile,corrosion potential-software fitting method is applied to study corrosion rate of tanks.Three coating materials(BPA,HY007 and ACME)are selected that referring to anticorrosion techniques of other oil fields and their adhesion,impact resistance and chemical resistance are tested.Finally,cathodic stripping resistance and electrochemical impendence methods are applied to investigate anticorrosion performance of the coatings.The research results show that:(1)Oxygen corrosion co-exists with sulfur corrosion.Corrosion rate of tank walls is about 1.0mm/a.All of the three types of coating materials have good cohesion,HY007 is best in compact resistance,followed by ACME and BPA is the poorest.Coatings are outstanding in chemical resistance except for HY007 who is sensitive to acids.(2)In temperature 65℃,BPA coating completely falls from the metal substrate after one-day cathodic stripping resistance;in terms of cathodic stripping resistance,ACME is obvious superior to HY007 and their average stripping value is 10.45 mm and 21.48 mm,respectively.(3)ACME is best in penetration resistance due to its unique scaly crystalloblastic texture.Electrochemical impendence of the coating is still about 1010?*cm2 after being soaked for 600 hours.Carbon steel where covered by HY007 coating begins to be corroded after being soaked for 360 hours.The impendence value of BPA declines with the prolonging of soaking time and the performance tend to poor.(4)Result of the immersion test indicates ACME coating has stable performance when there are corrosive mediums even worse in mediums with high content of sulfur,so there is huge potential field application for the coating.There is loss of color for HY007 coatings in oil,but it still have good protection for metal bases.