含Cr油套管钢CO_2腐蚀产物膜特征

CHARACTERISTICS OF CO_2 CORROSION SCALES ON Cr-CONTAINING N80 STEEL

在模拟油田CO2 腐蚀环境下 ,利用XRD、EDS、XPS和SEM研究了含Cr的N80钢腐蚀产物膜的特征 .结果表明 ,本试验条件下Cr在腐蚀产物膜中富积 ,形成非晶态物质Cr(OH) 3 ,使得腐蚀产物膜具有阳离子选择性 ,阳极反应受到抑制 ,腐蚀速率降低 .

While simulating the CO 2 corrosion environment in oilfield,the XRD,EDS,XPS and SEM techniques were adopted to study the characteristics of CO 2 corrosion scales on N80 steel containing Cr.The results demonstrated that Cr could be enriched in corrosion scales forming amorphous compound Cr(OH) 3,which made the corrosion scale has the character of cation-selectivity.This cation-selective scale could block anions such as Cl -,CO 2- 3 and HCO - 3 penetrating the corrosion scale and decrease the anionic concentration at the interface between matrix and corrosion scale.As a result,the anodic reactions could be suppressed and corrosion rate be reduced.