新型2Cr1Mo2Ni钢在含二氧化碳油田采出液中的腐蚀行为

Corrosion behavior of novel 2Cr1Mo2Ni steel in the oil field formation water containing CO_2

为弄清Mo和Ni元素在低Cr钢耐蚀方面所起的作用,炼制了新型2Cr1Mo2Ni钢,研究其在模拟油田采出液中的腐蚀行为,实验条件为80℃,0.8 MPaCO2分压.利用扫描电镜和能谱分析研究了2Cr1Mo2Ni钢和3Cr钢的腐蚀产物膜微观形貌和成分,测试了高温高压极化曲线和电化学阻抗谱,分析了腐蚀产物膜的生长过程.实验结果表明,Mo和Ni元素在提高抗CO_2腐蚀性能方面的作用不及Cr元素.2Cr1Mo2Ni钢腐蚀164 h后,中低频感抗弧消失,腐蚀产物膜开始完全覆盖基体表面;腐蚀240 h后,生成的腐蚀产物膜具有较好的保护性.

The corrosion behavior of the new 2Cr1Mo2Ni steel in the oil field formation water containing CO2 at 80 ℃ and 0.8MPa was studied herein to clarify the role of Ni and Mo in the corrosion resistance of low-Cr steel.The surface morphology and the chemical composition of the corrosion scales were analyzed by scanning electron microscopy and energy dispersive spectroscopy（EDS）.The polarization curves and the electrochemical impedance spectroscopy spectra were also obtained to explore the growth process of the corrosion scale.The results indicate that Mo and Ni are not as efficient as Cr in enhancing the corrosion resistance of the low-Cr steel.The low-frequency inductance loop disappears after 164 h immersion.Moreover,the corrosion scale completely covers the substrate surface.In addition,the protective corrosion scale forms after 240 h immersion.