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823 |
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Poster Presentation Funktionelle Oberflächen Functional surfaces |
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Hydrogen shielding film with self-healing function coated on stainless steel |
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Takahisa Yamazaki / Tokyo Institute of Technology, Japan Keisuke Shoji* / Tokyo Institute of Technology, Japan Toshi-Taka Ikeshoji/ Tokyo Institute of Technology, Japan Akio Suzumura/ Tokyo Institute of Tecnology, Japan Motoki Noko/ Tokyo Institute of Technology, Japan |
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In order to establish infrastructure for hydrogen energy resource, it is important to prevent hydrogen gas from permeating through stainless steel substances, and especially from penetrating into them. Characteristics of hydrogen permeation for the 316 stainless steel with different surface coating films are investigated. Examined surfaces are natural iron and chromium oxide films, chromium oxide films formed by low concentrated oxygen, and carbon films. The low concentrated oxide films and carbon films were deposited by glow discharge plasma after annealing and ion sputter cleaning. A stationary hydrogen flux from the stainless steel surface was measured by using a system with an orifice. The pressure difference of the specimen was maintained to be constant by controlling the gas flow rate from the orifice in low pressure vessel. The calculated value of hydrogen permeability, K, for natural oxide films on the 316 stainless steel substrate was 0.75×10-12. It was the least permeability compared to ones for other films, such as the chromium oxide films; 1.78×10-12. The natural oxide film is considered to play the desorption-role as a hydrogen shielding film rather than adsorption-role, since the specimen with carbon film on high pressure side and natural oxide film on low pressure side had lower hydrogen permeation than the inverted specimen setting. Throughout these experiments, it had come up that the hydrogenarated amorphous carbon (a-C:H) film would function as an effective hydrogen shielding film. It is also expected for the film to have a self-healing capacity when it is used under hydrogenous ambient. Small defects for hydrogen gas in the films might be healed promptly with replenishing hydrogen atoms from the atmosphere. We will report the performance of a-C:H films. |