Test Methods for Evaluating Materials for High-Pressure Hydrogen Gas Applications

The clean nature of hydrogen as an energy source is propelling the rapid development of applications and infrastructure for its production, storage, and distribution. One of the challenges for the widespread adoption of hydrogen as a fuel is identifying materials that can safely handle high pressures of hydrogen. Hydrogen Embrittlement is a well-known but not very well-understood mechanism of material failure in such applications. This paper gives a literature review of hydrogen embrittlement and the test methods that can be employed for measuring and qualifying materials for hydrogen applications. Slow Strain Rate Testing (SSRT) and fractography results for three austenitic steel grades performed at 85-87.5 MPa hydrogen pressure are described. Grade Alleima HP160 showed good resistance against hydrogen embrittlement despite its low Ni content compared to the two UNS 31603 alloys with different Ni contents. The results are interpreted in light of the Nickel equivalent of the alloys.