2006 Volume 55 Issue 4 Pages 139-145
Highly pressurized hydrogen gas is one of the most effective media for storage and transport of hydrogen for fuel cells. Mechanical properties of an aluminum alloy and austenitic stainless steels were investigated by Slow Strain Rate Testing (SSRT) in hydrogen environment pressurized at 45MPa, for ensuring the safety of materials used for the compressed hydrogen system. A6061-T6 aluminum alloy and stable austenitic stainless steel 316L showed no evidence of embrittlement even at extremely low strain rates (3×10-7-3×10-6s-1). In contrast, metastable austenitic stainless steel 304L showed considerable degradation of ductility in the hydrogen environment due to strain-induced martensitic transformation. Susceptibility to hydrogen environment embrittlement (HEE) could be discussed based on hydrogen content absorbed into the materials and threshold stress.