采用动电位极化和交流阻抗技术研究了NS4溶液中的溶解氧对X80管线钢在该溶液中耐蚀性的影响,通过SEM、XRD等对X80管线钢的腐蚀形貌和腐蚀产物进行了分析.结果表明,随着NS4溶液中溶解氧含量的减少,X80钢的腐蚀电位升高,腐蚀电流密度降低,腐蚀产物的致密性逐渐提高,XS0钢的耐蚀性增加;氧含量较高时,腐蚀产物表面高低不平,表面存在大量裂缝、孔洞等缺陷,表面致密性较差,氧含量减少后,腐蚀产物平整致密;随着溶解氧含量的不同,腐蚀后生成了不同的腐蚀产物.
Potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS) were employed to study the effect of dissolved oxygen (DO)on the corrosion behavior of X80 pipeline steel in NS4 solution at 20℃. The corroded surface and the composition of the corrosion products were examined by SEM and XRD. The experimental results of potentiodynamic polarization curves and EIS showed that with the decrease of dissolved oxygen in NS4 solution, the corrosion potential(E ) ennobled, corrosion current density (icorr)reduced and the corrosion resistance became larger. SEM observation indicated that the surface of corrosion products formed in solutions with high concentration of DO, had a lot of macro- cracks and cavities, and when the DO was decreased, the corrosion products became more consistent. XRD results indicated that the corrosion products formed during the experiments were varied corresponding to the content of DO in the solutions.