Abstract
To commercialize fuel cell vehicles and hydrogen filling stations, and to achieve a reliable and economical “hydrogen society”, international accordance of the material usage standard for high pressure gaseous hydrogen equipment is regarded as an important issue. Therefore, a precise method to evaluate the effect of gaseous hydrogen on structural metallic materials is required to qualify the materials compatibility for high pressure gaseous hydrogen equipment. For this purpose, our research group developed testing facilities such as slow strain rate tensile test, fracture toughness test, and delayed fracture test up to 120 MPa of gaseous hydrogen. We acquired operation expertise of the facilities and testing data of commercialized metallic materials. In particular, fracture testing methods of Cr-Mo standard steel in Japan and USA were compared in an international collaborative study between Sandia National Laboratories, Livermore and our research group. We concluded that estimating fracture toughness with a rising displacement is essential for testing method in a high pressure gaseous hydrogen environment.
