锅炉酸洗过氧化氢钝化工艺的电化学实验研究

Electrochemical study on hydrogen peroxide passivation during boiler pickling

摘要: 采用线性极化电阻技术和交流阻抗技术研究了锅炉水冷管材在过氧化氢溶液钝化条件下的电化学特征,结合SEM电子扫描技术对不同钝化条件下的钝化膜成膜形貌进行观察测量.实验结果表明,在柠檬酸漂洗后采用过氧化氢钝化的过程中,当过氧化氢的质量分数为0.1%,溶液pH为9.5,亚铁离子的质量浓度为100 mg·L^-1且氯离子的质量浓度低于50 mg·L^-1时钝化效果最好,钝化膜成膜形貌较为完整,管材抵抗外界腐蚀的能力最强.

Abstract: The linear polarization resistance and AC impedance techniques were applied to test the electrochemical performance of boiler water-cooling pipe steel in hydrogen peroxide solution.The microstructures of the pipe steel passivated in different conditions were observed by SEM.The experiment results show that when the mass fraction of hydrogen peroxide is 0.1%,the pH of the solution is 9.5,the mass concentration of ferrous ions is 100 mg·L^-1 and the mass concentration of chlorine ions is less than 50 mg·L^-1,the better passivation with H₂O₂ can be achieved after pickling with citric acid. An intact passive film has formed on the pipe steel and the corrosion resistance of the pipe steel is optimal.