Effect of Dissolved Oxygen on H₂S Corrosion Behavior of BNS Pipeline Steel

Based on a two-stage corrosion immersion test, the effect and mechanism of dissolved oxygen on H₂S corrosion behavior of BNS pipeline steel were studied. The results show that in H₂S environment, the mixture of oxygen could significantly promote the corrosion of BNS pipeline steel because of the formation of SO₄^2-, S₂O₃^2- and elemental sulfur in the reaction between O₂ and H₂S. Compared with the single H₂S environment, the corrosion product on BNS pipeline steel surface in the O₂/H₂S coexistence environment was much more and looser. The mixture of oxygen increased the localized corrosion sensitivity of BNS pipeline steel, which was contributed to dissolved oxygen, elemental sulfur and S₂O₃^2- generated by the reaction between H₂S and O₂.