物理化学学报 >> 2003, Vol. 19 >> Issue (05): 403-407.doi: 10.3866/PKU.WHXB20030505

研究论文 上一篇    下一篇

模拟冷却水中不锈钢的自钝化及硫离子的影响

葛红花;周国定;吴文权   

  1. 上海电力学院电化学研究室,上海 200090;上海理工大学动力学院,上海 200093
  • 收稿日期:2002-09-11 修回日期:2002-11-04 发布日期:2003-05-15
  • 通讯作者: 葛红花 E-mail:honghge@hotmail.com

The Spontaneous Passivation of Stainless Steel in Simulated Cooling Water and the Influence of Sulfide

Ge Hong-Hua;Zhou Guo-Ding;Wu Wen-Quan   

  1. Electrochemical Research Group, Shanghai College of Electric Power, Shanghai 200090;College of Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093
  • Received:2002-09-11 Revised:2002-11-04 Published:2003-05-15
  • Contact: Ge Hong-Hua E-mail:honghge@hotmail.com

摘要: 通过对316#不锈钢/模拟冷却水体系电化学阻抗谱(EIS)的测定和拟合,确定了合适的模型.根据此模型,膜电阻R2在电极浸泡过程中增大, 反映膜电容的Y02值则不断减小,显示钝化膜的增厚和致密.模拟冷却水中硫离子的加入使R2迅速降低.Mott-Schottky图测定显示,在模拟冷却水中浸泡65天的不锈钢钝化膜的施主密度ND和受主密度NA分别为1.47×1020和2.20×1020 cm-3,加入9 mg•L-1硫离子1 h后, ND和NA分别上升到4.52×1020和7.02×1020 cm-3.极化曲线测定表明9 mg•L-1硫离子使不锈钢钝态电流增大了近一倍.

关键词: Mott-Schottky图, 电化学阻抗谱(EIS), 钝化膜, 不锈钢, 硫离子

Abstract: The spontaneous passivation of 316# stainless steel in simulated cooling water is studied by electrochemical impedance spectroscopy, and a suitable model is chosen through fitting. It is shown that the film resistance R2 increases while the value of Y02 , which reflects the film capacitance decreases continuously in the course of immersion of the electrode, but R2 decreases sharply with addition of sulfide. The Mott-Schottky plots show that the donor and accepter densities of the passive films on stainless steel immersed in simulated cooling water for 65 days have the values of 1.47×1020 cm-3 and 2.20×1020 cm-3, respectively, but the values increase to 4.52×1020 cm-3 and 7.02×1020 cm-3 after the addition of 9 mg•L-1 sulfide for 1 h. The polarization curves indicate that the passive current rises in the presence of sulfide.

Key words: Mott-Schottky plot, Electrochemical impedance spectroscopy, Passive film, Stainless steel, Sulfide