高酸性条件下S沉积对N80碳钢腐蚀的研究

Sulfur Deposition on Corrosion of N80 Carbon Steel in High Acid Environment

研究了在模拟普光气田高酸性环境中,沉积S对N80碳钢腐蚀的影响。用环境扫描电镜观察了碳钢表面腐蚀产物的形貌。采用失重法分析比较了不同形态的沉积S(悬浮S和涂S)对碳钢在模拟环境中腐蚀的影响,用电化学方法研究其腐蚀过程。结果表明:湿态S(液相条件下的涂S)以局部腐蚀为主,S与碳钢的直接接触会加速碳钢的腐蚀。电化学方法表明,S沉积层下在碳钢表面的产物与钢形成闭塞的电偶腐蚀原电池,促进阴极催化反应的极化过程。可能是S的存在催化酸腐蚀,从而加速碳钢腐蚀。

Sulfur deposition had the effect on corrosion of N80 carbon steel, which was studied in high acid environment of Puguang gas field, then the corrosion production was analyzed by E- SEM. The mass loss method compared the effects of sulfur in various forms （blank, sulfur powder and molten sulfur coverage on the carbon steel） for carbon steel corrosion in environment, and the electrochemistry method discussed the corrosion mainly for local corrosion, sulfur had the direct process. The results showed that： the wet sulfur is contact with steel which would accelerate carbon steel corrosion. The electrochemistry method showed that elemental sulfur deposition accelerated carbon steel corrosion by promoting cathode polarization reaction process. The possible reason is that the sulfur catalyzed acid corrosion, thus resulting in the carbon steel corrosion.