水轮机用45钢在模拟服役环境中的电化学腐蚀性能研究

针对四川水电站过流部件的腐蚀问题,采用动电位极化、电化学阻抗谱等方法研究了在不同阴离子浓度下模拟河水对45钢腐蚀电化学的腐蚀行为,运用SEM、EDS及XRD分析了腐蚀产物的形貌与成分。结果表明:随HCO3-及Cl-浓度由0.4 g/L增加至1.2 g/L,45钢在模拟溶液中的腐蚀速率增大;随着SO42-浓度由0.4 g/L增加至1.2 g/L,腐蚀速率减小。45碳钢的腐蚀速率可能与阴离子之间的催化或竞争吸附有关以及与腐蚀产物的保护膜层的完整性有关。

Study on Electrochemical Corrosion Properties of 45 Steel for Hydraulic Turbines in Simulated Operation Environment

For studying the corrosion problem of turbine components for hydropower station in Sichuan province,the electrochemical corrosion behavior of 45 steel in simulated river water containing different anions was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy,and the morphology and composition of corrosion products were characterized by SEM,EDS and XRD.Results showed that as the concentrations of HCO3-and Cl-increased from 0.4 g/L to 1.2 g/L,the corrosion rate of 45 steel in simulated solution rose.On the contrary,when the concentration of SO42-increased from 0.4 g/L to 2.0 g/L,the corrosion rate decreased.In general,the corrosion rate of 45 steel might be related to the catalyst reaction or competitive adsorption of various anions and the completeness of corrosion product protective films.