海管X70钢海底服役环境下CO2腐蚀的临界温度的研究.pdfVIP

海管 X70 钢海底服役环境下 CO 腐蚀的临界温度研究 2 * 李少飞 柳伟 张晶 李函 路民旭 北京科技大学新材料技术研究院，北京 100083 摘要 利用电化学技术分别测量了海管用 X70 钢在不同服役温度条件下的 CO2 腐蚀电化学阻抗谱、线性极化电阻 和自然腐蚀电位，并对 X70 钢进行了不同温度条件下的高压 CO2 模拟实验。结果表明： 随着海管服役温度的升 高，腐蚀电流密度先增大后减小，30 ℃时出现较大增加，在 70 ℃达到极大值；电化学阻抗谱的电荷传递电阻 Rt 减小，腐蚀阻力降低，阳极溶解得到促进；X70 钢的平均腐蚀速率随温度的升高先增大后减小，30 ℃时突然增 大，70 ℃为极大值；70℃以下发生全面腐蚀，80 ℃发生局部腐蚀。 关键词 X70 钢；临界温度；电化学性能；腐蚀速率 Research on the Critical Temperature of CO2 Corrosion on Subsea Pipeline Steel X70 in Subsea Service Environment LI Shao-fei, LIU Wei*, ZHANG Jing, LI Han ， LU Min-xu Institute of Advanced Materials, University of Science and Technology Beijing, Beijing 100083, China Abstract In order to investigate the effect of servicetemperature on CO2 corrosion behavior of subsea pipeline steel X70, electrochemical measurement techniques were employed to determine the electrochemical impedance spectra (EIS) ，linear polarization resistance (LPR) and corrosion potential(Ecorr ) under different temperature. Corrosion experiments of X70 steel were conducted by a high pressure autoclave. The results show that with the increase of sevice temperature, corrosion current density increases at first and then decrease, and the corrosion current density inceases quickly at 30 ℃, and reaches the maximum value at 70 ℃; The charge transfer resistance of electrochemical impedance spectra (EIS) shows the decrease tendency, which means the corrosion resistance become lower and anodic dissolution increases; The average corrosion rate of X70 steel increases with the rising of temperature and then reduces. It h