Global Harmonization of Fatigue Life Testing in Gaseous Hydrogen

Methods to qualify materials for hydrogen service are needed in the global marketplace to enable sustainable, low-carbon energy technologies, such as hydrogen fuel cell electric vehicles. Existing requirements for qualifying materials are not adequate to support growth of hydrogen technology as well as being inconsistent with the growing literature on the effects of hydrogen on fracture and fatigue. This report documents an internationally coordinated effort to develop a test method for qualifying materials for high-pressure hydrogen fuel system onboard fuel cell electric vehicles. In particular, consistency of fatigue life testing strategies is discussed. Fatigue life tests were conducted at three different institutes in high-pressure gaseous hydrogen (90 MPa) at low temperature (233K) to confirm consistency across distinct testing platforms. The testing campaign includes testing of both smooth and notched axial fatigue specimens at various combinations of pressure and temperature. Collectively these testing results provide insight to the sensitivity of fatigue life testing to important testing parameters such as pressure, temperature and the presence of stress concentrations.