N80油管钢CO_2腐蚀点蚀行为

BEHAVIOR OF CO_2 PITTING CORROSION OF N80 STEEL

在模拟油田CO2 腐蚀环境下 ,利用XRD、EDS和SEM研究了N80钢点蚀坑的形成与发展 .结果表明 ,Cl-会在腐蚀产物膜与金属界面处富积成核 ,加速该区域的阳极溶解 ,促使点蚀坑的形核 ;点蚀坑内也有Cl-富积 ,在膜与基体界面处形成厚度为 3 μm的富积层 ,加速点蚀坑内基体的腐蚀 ,使得点蚀坑进一步发展 .同时 。

In simulating the environment of CO_2 corrosion in oilfield,the XRD,EDS and SEM techniques were adopted to study the formation and development of CO_2 pitting corrosion on N80 steel.The results demonstrated that Cl - anions could be enriched and nucleated at the interface between corrosion scale and matrix,which subsequently catalyzed the formation of pitting.Whereas pits could also be enriched by Cl - forming approximately 3 μm enrichment layer at interface,thus leading to the further development of pitting.In present case,the relationship between mechanisms of anodic reaction and morphology of pitting was discussed.