Effect of Expansion, Moisture on Fracture Toughness in High Pressure Hydrogen Environment

Abstract Hydrogen is considered one of the options to be used as an alternate fuel source to reduce carbon emissions. Towards this there is growing interest in using underground storage for hydrogen gas (H2) which can be stored in larger volumes, than surface storage options would allow for. While underground well storage of natural gas is widely understood; there is far less experience in storing H2 only or H2 in blend with natural gas. An area of knowledge gap is the compatibility of metallic materials that need to be used for well construction for underground storage as the assessment of risk for Hydrogen Embrittlement (HE) would need to be addressed. In this study, which is a continuation of work published in the last two years, effect of high-pressure H2 gas on in-situ expanded 4130 Modified (4130M) low alloy steel was studied.1,2 Additionally, effect of water-phase as moisture, fully wet conditions as an impurity with H2 gas on high strength low alloy steel, super martensitic stainless steel was evaluated. Testing was performed via Fracture Toughness testing in both inert and high pressure H2 gas environment per ASTM E1820.3 Details of this assessment and post testing evaluation of the specimens will be provided in this paper.