水素ステーション水素漏洩トラブルの解析とsus316lフレキシブルホースの疲労寿命予測

摘要

The fatigue failure analysis of SUS316L flexible hose of the hydrogen station which was demonstrated during EXPO 2005 in Nagoya was carried out. The fatigue fracture surface where hydrogen leakage was detected showed clear striations which revealed a unique evidence of hydrogen effect on the ratio of striation height and spacing. The number of striations observed on the leakage fracture surface was 270. Considering that the number of hydrogen supply to the fuel cell buses was 280, it can be concluded that the fatigue fracture process during the demonstration is completely controlled by microplasticity resulting ductile fracture contrary to the conventional concept expressed with a term of decohesion or hydrogen embrittlement. The striation data were used to make the fatigue crack growth rate equation which was applied to the life prediction and structural integrity assessment for a new hydrogen station. The fatigue crack growth data showed the evidence of a strong frequency effect of fatigue crack growth rate of SUS316L used in the hydrogen environment with 8 minutes hydrogen supply time at the hydrogen station.%地球環境問題の面から次世代ェネルギーとしてのrn水素利用が世界的に注目され，水素利用のための研究，rn開発が活発に行われるようになった．これは，地球温rn暖化の制約を逃れられない化石燃料に依存する世界経rn済を「炭素のサイクル」から「水素のサイクル」に転rn換する壮大な戦略でもある．水素を燃料とした燃料電rn他車や定置用燃料電池の開発・実用化が最重要課題とrnされている．2003年，IPHE（水素社会のための国際rnパートナーシップ）が創設されたが，日本政府は,rn2020年に500万台の燃料電池車の導入を目指してぃる．