著者

李 松杰 秋山 英二 篠原 正 松岡 和巳 押川 渡

出版者

一般社団法人 日本鉄鋼協会

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.99, no.11, pp.651-658, 2013 (Released:2013-10-31)

参考文献数

42

被引用文献数

5

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Electrochemical hydrogen permeation tests of pure Fe sheets rusted by cyclic corrosion test (CCT) and atmospheric exposure were carried out under controlled temperature and humidity to investigate the influence of atmospheric corrosion on the hydrogen entry behavior. The hydrogen entry into the Fe specimens rusted by CCT increased under wet condition, and the hydrogen entry was increased with the CCT cycle number. During drying process after the wetting, hydrogen entry was further enhanced and a peak of hydrogen current was observed. The peak hydrogen permeation current tended to increase with the growth of rust layer, and the peak value of the hydrogen permeation current became remarkably higher than that at the highest humidity when the rust layer was relatively thick. Similar enhancement of hydrogen entry into an outdoor-exposed specimen was also observed during drying. Drying process after CCT resulted in an increase in hydrogen content of 5 mm-thick steel specimens measured by means of thermal desorption analysis, indicating the enhancement of hydrogen entry during drying process and showing a good agreement with the electrochemical hydrogen permeation test results. It is required to take into consideration the enhanced hydrogen entry to estimate concentration of hydrogen from the environment.

著者

秋山 英二 李 松杰 片山 英樹 張 波萍 趙 楷 押川 渡

出版者

一般社団法人 日本鉄鋼協会

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.103, no.2, pp.93-100, 2017

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<p>Electrochemical hydrogen permeation tests were carried out under controlled temperature and humidity using pure Fe sheet specimens outdoor-exposed at Beijing and Chongqing, China and Okinawa, Japan in order to understand the effect of environmental factors on hydrogen uptake behavior. The maximum hydrogen permeation current densities of the exposed specimens were in the order of Beijing > Chongqing >> Okinawa, while the order of the degree of corrosion of the specimens was Okinawa > Chongqing >> Beijing. X-ray fluorescence analysis showed that the surface concentrations of sulfur on the Beijing- and Chongqing-exposed specimens were higher than that of the Okinawa-exposed specimens, whereas chlorine concentrations of the Beijing and Okinawa-exposed specimens were higher than that of the Chongqing-exposed specimen. Nitrate concentrations of Beijing- and Chongqing-exposed specimens evaluated using nitrate test strips were obviously higher than that of the Okinawa-exposed specimens. It is suggested that air pollutants such as SO₂ and NO₂ and particulate matters containing inorganic acid ions, likely sulfate and nitrate ions, and possibly organic acids contribute to acidification of rust layer leading to the enhanced hydrogen entry.</p>