Reduction of hydrogen permeation using irradiation defects prodeced by helium ionirradiation

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04718
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26030:Composite materials and interfaces-related
• Research Institution: Hokkaido University
• Principal Investigator: Nobuta Yuji 北海道大学, 工学研究院, 助教 (80446450)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 水素ガスバリア / ステンレス鋼 / 水素透過 / ヘリウムイオン照射 / 照射欠陥 / ヘリウム気泡

Outline of Final Research Achievements

Hydrogen isotopes can easily penetrate metal, which leads to leakage ofhydrogen from hydrogen container. Therefore, it is important to develop a method to prevent hydrogen permeation. In the present study, the effects of irradiation defects created by helium ion irradiation on suppression of hydrogen permeation in stainless steel were investigated. As the temperature of stainless steel during helium ion irradiation increased, larger helium bubbles were observed just beneath the surface and hydrogen permeation was reduced. These results suggest that hydrogen permeation was suppressed due to the compression field created by high-pressure helium bubbles.

Free Research Field

核融合炉工学

Academic Significance and Societal Importance of the Research Achievements

水素利用が広まる中で水素の漏洩を抑制する技術の需要が増している．このような技術として，水素が透過しづらい材料を薄膜として水素容器表面にコーティングする手法が主流となっている．いっぽう，コーティング膜は剥離やクラックなどの潜在的な弱点を有する．本研究は，ヘリウムイオン照射により形成される照射欠陥層を利用し，材料表面そのものを水素が侵入しづらい性質に変えることができる技術である．そのため，コーティング法と組み合わせて使うことでコーティング法の弱点を補完し，水素の漏洩をさらに抑制する技術として期待できる．