Microbiological Corrosion Rules of X80 Pipeline Steel in Three Simulated Soil Solutions

Immersion test for 14 days and electrochemical test were carried out in Yingtan, Shenyang and Dagang simulated soil solutions with sulfate-reducing bacteria(SRB), the microbiological corrosion rules of X80 steel in the three simulated soil solutions were studied. The results show that the corrosion rates of X80 steel in Dagang simulated soil solution was maximum, and the corrosion rate in Yingtan simulated soil solution was minimum. The combined action of SRB and Cl- promoted the formation of pits on X80 steel surface. The corrosion process of X80 steel in three simulation soil solutions was the same, the cathodic process was predominantly controlled by hydrogen reduction, the anodic dissolution generated the yellow loose corrosion products FeO(OH), and Fe2+ with SRB produced iron sulfur compounds. The hydrolysis reaction was inhibited in Yingtan soil with a lower pH. Due to the corrosion process was controlled by cathodic reduction, therefore FeS did not detect in corrosion products formed in Dagang simulated soil solution.