温度对N80钢在饱和CO2地层水中腐蚀电化学性能的影响

EFFECT OF TEMPERATURE ON THE ELECTROCHEMICAL PROPERTIES OF N80 STEEL CO_2 CORROSION IN STRATUM WATER

利用交流阻抗技术研究了温度对N80油套管钢在模拟地层水中CO2腐蚀过程的影响。结果表明,低温下阻抗谱出现了高频容抗弧、中低频感抗弧和低频容抗弧3个时间常数,其中高频容抗弧与双电层电容和传递电阻有关,感抗弧对应膜的活性溶解,低频容抗弧与试样表面膜的生成有关。随着温度的升高,感抗弧逐渐缩小,直至消失,而低频的容抗弧则逐渐扩大,表明温度的升高有利于腐蚀膜的生成。随着浸泡时间的延长和温度的升高,腐蚀过程的传递电阻增加,这与高温下生成腐蚀膜的致密性有关。

The effect of temp detected using electrochemical erature on CO2 corrosion process of N80 steel in simulated stratum water was impedance spectroscopy （EIS）.The results showed that in the spectroscopy appeared three time constants,i.e.,the capacitance of high frequency,the inductance of middle and low frequency,the capacitance of low frequency. The capacitance appearing at high frequency is related to the capacitance of the double layer and transfer resistance, the inductance is attributed to the dissolution of the film, and the capacitance of low frequency is related to the formation of the film. With the temperature increasing, the inductance shrank, and the capacitance in low frequency enlarged, these indicated that increas temperature may accelerate the formation of the corrosion film. The transfer resistance of corrosion process increased with the increment of temperature and prolonging the immersion time,this is related to the compact property of the corrosion film.