X80管线钢钝化膜电化学性能的EIS研究

EIS analysis on electrochemical properties of passive film formed on X80 pipeline steel

目的研究成膜电位、温度和氯离子等对X80管线钢在1 mol/L NaHCO3/0.5 mol/L Na2CO3缓冲溶液中所形成的钝化膜的电化学性能的影响。方法利用电化学阻抗谱技术研究了X80管线钢在1 mol/L NaHCO3/0.5 mol/L Na2CO3缓冲溶液中所形成的钝化膜的电化学性能。结果随着成膜电位的增加,传递电阻R1减小,而膜电阻R2和扩散阻抗YW增加,表明膜的致密性增加;成膜温度升高,传递电阻R1、膜电容Q2和膜电阻R2减小,说明膜的致密性减小;同一温度下增加溶液中的氯离子浓度,传递电阻R1、膜电容Q2和膜电阻R2均减小;在同一氯离子浓度下升高温度,传递电阻R1、膜电容Q2和膜电阻R2均减小。结论成膜电位、成膜温度和氯离子会对钝化膜的电化学性能产生显著的影响。

Aim To investigate electrochemical properties of passive film formed on X80 pipeline steel in 1 mol/L NaHCO3/0.5 mol/L Na2CO3 buffer solution.Methods The electrochemical properties of passive film formed on X80 pipeline steel in 1 mol/L NaHCO3/0.5 mol/L Na2CO3 buffer solution were investigated by electrochemical impedance spectra（EIS）.Results The transfer resistance R1 decreased,film resistance R2 and diffusion impedance YW increased with increasing the formation potential,which indicated the improvement of the compactness of the film;the transfer resistance R1,film resistance R2 and film capacitance Q2 decreased with increasing the formation temperature,which showed the compactness of passive film decreased;the transfer resistance R1,film resistance R2 and film capacitance Q2 decreased with increasing chloride ion concentration at the same formation temperature;while,in the solution containing the same chloride ion concentration,the transfer resistance R1,film resistance R2 and film capacitance Q2 decreased with the increasing of the formation temperature.Conclusion The results showed that formation potential,formation temperature and chloride ion can affect the electrical properties of the passive film.