标题：Effects of hydrogen on current oscillations during electro-oxidation of X70 carbon steel in phosphoric acid
作者：L. Li;J. L. Luo;J. G. Yu;Y. M. Zeng;B. T. Lu;S. H. Chen
作者机构：[Li, L] Department of Chemical Engineering, University of Alberta, Edmonton, Alta. T6G 2G6, Canada, Department of Chemistry, Shandong University, Jina 更多
通讯作者地址：[Luo, JL]Univ Alberta, Dept Chem & Mat Engn, Edmonton, AB T6G 2G6, Canada.
关键词：hydrogen;passive film;carbon steel;oscillatory electrodissolution;SRET
摘要：It is the first time that the oscillatory electrodissolution of metals is used to study hydrogen-promoted corrosion, and the primary results prove that it is an effective method for investigating the effect of hydrogen on both the formation and dissolution of a passive film. Effects of hydrogen on the electrochemical oscillations of X70 carbon steel are investigated in 5.0 M H_3PO_4 solution. During the oscillatory electrodissolution of X70 steel electrode, the chemical environment near the surface of the electrode is changed artificially by the oxidation of hydrogen diffused from X70 electrode to surface. With increasing hydrogen pre-charging current density, both the induction time and the ratio of active time to passive time of the current oscillations increase, and the Flade which retards the formation of a passive film and subsequently promotes its dissolution. This investigation provides further understanding of the effect of hydrogen on the formation and dissolution processes of passive films. It is the first time to observe the periodical changes in the potential at the electrode/electrolyte interface during current oscillations by using scanning reference electrode technology. The scanning reference electrode technology is also used to verify the effect of hydrogen on the current oscillations.