20#钢在含饱和CO2的离子液体醇胺溶液中的腐蚀行为研究

Corrosion Behavior of 20# Steel in Alkanolamine Solution Mixed with Ionic Liquid Containing Saturated CO2

利用腐蚀失重实验研究了20#钢在含饱和CO2的离子液体醇胺混合溶液中的腐蚀行为,并结合SEM和EDS等技术研究了腐蚀产物膜及金属表面的形态。利用EIS拟合等效电路分析了电极表面状态,利用动电位扫描法分析了钝化区的钝化规律。结果表明,单乙醇胺(MEA)易与CO2发生降解反应,生成的降解产物在实验条件下会导致极严重均匀腐蚀;添加[Bmim]BF4离子液体后,对20#钢的腐蚀有抑制作用,使得均匀腐蚀速率减小;但由于混合溶液中BF4-的存在,使得钝化区范围变窄,从而诱发20#钢产生点蚀。

The corrosion behavior of 20#steel in CO2 saturated mixture liquor of alkanolamine solution with ionic liquid([Bmim]BF4)was studied by means of weight loss measurement,electrochemical impedance spectroscopy(EIS)and SEM equipped with EDS.The results showed that monoethanolamine(MEA)was easy to degrade with CO2,and the formed degradation products would lead to severe corrosion of 20#steel in experimental conditions.When the[Bmim]BF4 was added,the corrosion of 20#steel was inhibited and hence its uniform corrosion rate was reduced.Besides,due to the existence of BF4-in[Bmim]BF4,the range of passivation zone is narrowed,which is an important cause for pitting corrosion of20#steel.