In this work, hydrogen absorption and the permeation behavior of the passive layer formed on zircaloy-4 are in- vestigated. Potentiodynamic polarization, Mott-Schottky analysis, electrochemical impedance spectroscopy,...In this work, hydrogen absorption and the permeation behavior of the passive layer formed on zircaloy-4 are in- vestigated. Potentiodynamic polarization, Mott-Schottky analysis, electrochemical impedance spectroscopy, and Raman scattering spectroscopy are employed to characterize the passive defects before and after hydrogen permeation. It is found that the nanoscale passive ZrO2 films play an important role in the resistance against corrosion; hydrogen impingement, however, reduces the passive impedance towards hydrothermal oxidation. The increase of defects （vacancies） in passive film is probably attributed to the degradation. We believe that this finding will provide valuable insight into the understanding of the corrosion mechanism of zircaloys used in light water reactors.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2011CB610501)the Funds from the State Key Laboratory of Surface and Chemistry,China(Grant No.SPC 201102)the Reactor Fuel and Materials Laboratory,China(Grant No.STRFML-2013-05)
文摘In this work, hydrogen absorption and the permeation behavior of the passive layer formed on zircaloy-4 are in- vestigated. Potentiodynamic polarization, Mott-Schottky analysis, electrochemical impedance spectroscopy, and Raman scattering spectroscopy are employed to characterize the passive defects before and after hydrogen permeation. It is found that the nanoscale passive ZrO2 films play an important role in the resistance against corrosion; hydrogen impingement, however, reduces the passive impedance towards hydrothermal oxidation. The increase of defects （vacancies） in passive film is probably attributed to the degradation. We believe that this finding will provide valuable insight into the understanding of the corrosion mechanism of zircaloys used in light water reactors.
