Role of Sulfide Ion on Corrosion Performance of Pipeline Steel in Simulated Inner-seeper Environment

摘要

The role of sulfide ion on corrosion performance of pipeline steel (Q235B) is studied in simulated inner-seeper environment by electrochemical methods. Results show that the corrosion of Q235B steel is promoted with low sulfide ion concentration. The Q235B steel has the maximum corrosion rate when the concentration of sulfide ion is 20mg/L, but passivation effect is found with the time prolongation. High concentration of sulfide ion has obvious corrosion inhibition effect to Q235B steel. The concentration of sulfide ion greatly affects the surface morphology of Q235B steel. The pitting corrosion is more obvious with low sulfide ion concentration. General corrosion happens with the increase of sulfide ion concentration, while the compact passive Fe3S4 corrosion product film is found with higher sulfide ion concentration, which has certain protection on Q235B steel matrix.