O_2/CO_2共存环境下缓蚀剂抑制碳钢腐蚀的机理研究  

Corrosion Inhibition Mechanism of Carbon Steel in O_2/CO_2 Coexisting Environment

作　　者：王贝[1] 许立宁[1] 李东阳[1] 路民旭[1] WANG Bei XU Li-ning LI Dong-yang LU Min-xu(Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China)

机构地区：[1]北京科技大学新材料技术研究院,北京100083

出　　处：《材料工程》2017年第5期38-45,共8页Journal of Materials Engineering

基　　金：国家科技重大专项资助项目(2011ZX05056)

摘　　要：利用旋转圆盘电极(RDE)研究O_2/CO_2共存环境下,碳钢管线在不同浓度缓蚀剂中的腐蚀电化学行为。通过与CO_2环境中进行对比,研究得到O_2对缓蚀剂抑制碳钢CO_2腐蚀的影响。采用极化曲线测试不同浓度缓蚀剂下的缓蚀效率及阴、阳极行为,利用交流阻抗技术(EIS)监测缓蚀剂的吸附行为及腐蚀过程,并通过EIS拟合出的数据计算并绘制吸附等温线,利用扫描电镜观察含氧条件下的腐蚀形貌,利用XRD分析腐蚀产物膜的成分。结果表明:O_2导致缓蚀剂分子吸附能力减弱,在碳钢表面的吸附量减少,吸附膜覆盖度变小,缓蚀效率明显降低。同时,在有O_2环境下,腐蚀产物主要为疏松多孔的Fe_2O_3和FeO(OH)。由于含氧条件下腐蚀速率增大,腐蚀产物膜生成速率加快,导致缓蚀剂吸附能力进一步减弱,缓蚀剂有效作用时间变短。The electrochemical behavior of carbon steel pipeline in simulated solutions containing different concentrations of inhibitor saturated with O2/CO2 was studied by rotating disk electrode （RDE）. After comparison with the results tested in CO2 environment, the effect of O2 on the inhibition performance of inhibitor A on the carbon steel was obtained.Potentiodynamic polarization was used to test the inhibition efficiency of inhibitor A. The EIS was used to study the adsorption behavior of the inhibitor and the corrosion process. The data calculated from the EIS fitting were used to study the adsorption behavior of the inhibitor. The morphology and the compositions of the corrosion product were observed by using SEM and XRD respectively. The results indicate that oxygen weakens the adsorption capacity of the inhibitor, which results in less adsorption film coverage ratio of the inhibitor on the steel surface and decreases corrosion inhibition efficiency. The corrosion products are loose and porous Fe2O3 and FeO（OH） in the environment of O2 and CO2 coexisting. The effective acting time of the inhibitor is shortened owing to the increasing corrosion rate and fast growth of the corrosion products in O2/CO2 environment, which results in more weakened adsorption capacity of the inhibitor.

关 键 词：碳钢  O2/CO2腐蚀  缓蚀剂  旋转圆盘电极  吸附等温线  腐蚀电化学 

分 类 号：TG174[金属学及工艺—金属表面处理]