Q235钢在三元复合驱溶液中电化学腐蚀研究

Electrochemical corrosion behavior of Q235 Steel in alkali-surfactant-polymer solutions

采用电化学综合测试系统对油田常用管线钢Q235在以碱(Alkali)、表面活性剂(Surfactant)和聚合物(Polymer)的三元复合驱(ASP)溶液中腐蚀电化学行为进行了测试。研究了不同温度和pH值对其腐蚀行为影响。用扫描电镜(SEM)对浸泡腐蚀后试件表面进行了分析。结果表明:随温度升高,Q235钢电化学阻抗谱容抗半径降低,腐蚀阻力降低,腐蚀速率加大,主要与腐蚀产物膜减薄有关。随pH值升高,腐蚀速率减小并趋于平稳,主要取决于OH-的放电电位。静态浸泡后主要发生均匀腐蚀,腐蚀产物膜疏松,无点蚀。

The corrosion behavior of Q235 oil pipeline steel in Alkali -Surfactant- Polymer （ASP） solution was investigated by electrochemical methods. The impacts of temperature and pH on corrosion behavior were also studied. The corroded surface of coupon was analyzed by Scanning Electron Microscope （SEM）. The results showed that the corrosion rate of Q235 steel gradually increased with rising temperature because of reduction of corrosion resistance and thinning of thickness of corrosive products film. The corrosion rate decreased wilh increase of pH and attained to a stabilized trend. This was related to the discharge potential of the OH -. After submersion, the Q235 steel exhibited uniform corrosion behavior with porous corrosive product film and no obvious pitting.