曼尼希碱与硫脲在气井采出水腐蚀体系中的缓蚀协同作用  

Synergistic Inhibition Mechanism of Mannich Bases and Thiourea in Corrosion System of Gas-field Wastewater

作　　者：孟凡宁[1] 李谦定[1] 李善建[1] 

机构地区：[1]西安石油大学化学化工学院,西安710065

出　　处：《表面技术》2014年第3期90-94,110,共6页Surface Technology

基　　金：西安石油大学全日制硕士研究生创新基金资助(2013cx120734)~~

摘　　要：目的寻找新型缓蚀剂,以解决碳钢在气井采出水中的腐蚀问题。方法以N80钢在80℃气井采出水中的腐蚀为研究对象,通过极化曲线和电化学阻抗谱,研究曼尼希碱与硫脲进行复配的缓蚀效果,并探讨缓蚀协同作用机理。结果硫脲是一种混合型缓蚀剂,对N80钢的阴极过程和阳极过程都有强烈的抑制作用;曼尼希碱是一种以抑制阴极为主的混合型缓蚀剂。二者复配后,对N80钢在气井采出水中的腐蚀表现出优异的缓蚀协同效应,当曼尼希碱添加量为0.75%,硫脲的质量浓度为2.5 mg/L时,缓蚀效果最好。结论曼尼希碱与硫脲二者复配使用时,在N80钢表面可能形成一种双层结构的吸附膜,内层以硫脲为主,外层以曼妮希碱为主。Objective To find new inhibitors of carbon steel corrosion in gas-field wastewater. Methods The synergistic inhibi- tion effect of mannich （MABS） and thiourea （TU） on N80 carbon steel in corrosion system of gas-field wastewater was investigated by using polarization curves and electrochemical impedance spectroscopy （EIS）. Results The results showed that TU had strong in- hibition effect on the anodic and cathodic processes of N80 steel corrosion, while MABS acted as mixed-type inhibitor preferentially restraining the cathodic process of metal. The combination of MABS and TU showed excellent synergistic inhibition effect in gas- field wastewater. When the Mannieh and thiourea concentration was 0.75 % and 2.5 mg/L, respectively, the inhibition effect was the best. Conclusion When using the combination of MABS and TU, a hi-layer inhibitor film with the inner layer of TU molecules and the outer layer of mannich molecules was formed on the N80 steel surface.

关 键 词：缓蚀剂 协同作用 曼尼希碱 硫脲 

分 类 号：TG174.42[金属学及工艺—金属表面处理]