X70管线钢在NaCl溶液中不同温度下的电化学腐蚀行为研究

Study of Electrochemical Corrosion Behavior of X70 Pipeline Steel in NaCI Solution at Different Temperatures

采用电化学极化曲线和交流阻抗测试方法，研究了不同温度下0．5％NaCl溶液中XTO管线钢的电化学腐蚀行为。结果表明，极化曲线测试中，随着温度的升高，自腐蚀电流密度增大，电化学反应速度加快；交流阻抗测试中，随着温度的升高，极化电阻值减少，反应速度加快。2种测试方法均证明了温度的升高可以促进点蚀的发生。

The electrochemical corrosion behaviors of X70 pipeline steel in 0. 5% NaCl solution at different temperatures have been studied by polarization curve and electrochemical impedance spectroscopy （EIS） tests. The results showed that in polarization curve test, when the temperature rised, the corrosion current density increased, the electrochemical reaction speed increased. In EIS test, with the temperature rised the polarization resistance decreased, the corrosion rate increased. Both tests proved that the rise of in temperature promoted the occurrence of pitting corrosion.