Ductility-driven ranking system for API-grade steels in high pressure gaseous hydrogen transmission pipelines
Douglas Stalheim, Andrew Slifka, Matthew Connolly, Enrico Lucon, Aaron Litschewski, Pello Uranga
There is strong economic and environmental interest in hydrogen as an energy source to contribute to combatting climate change. Hydrogen diffusion into the steel with assistance through various mechanisms of corrosion and pressure will degrade the mechanical properties, primarily critical ductility properties of fracture toughness and fatigue, through embrittlement or hydrogen induced cracking. Fracture toughness as a measure of crack arrest performance through required Charpy (TCVN) performance represents a principal mechanical property requirement of the pipeline. Ductility performance, regardless of the environment, which consists of % RA, fracture toughness, fatigue, etc. is driven primarily by metallurgical components of the through-thickness microstructure such as average high angle grain boundary (HAGB) unit cell size and homogeneity of the HAGB's. A relationship can perhaps be developed of ductility attributes such as TCVN performance in air vs. fracture toughness in hydrogen. This correlation between TCVN ductility performance, in conjunction with through-thickness microstructural components, and fracture toughness performance in hydrogen will be used to create a ranking methodology and perhaps propose an additional "Option C" qualification to the ASME B31.12 Code for Hydrogen Piping and Pipelines. This paper will present the background analysis, evaluation, development of the logic, proposed B31.12 code language and how to implement the logic.
Proceedings of the ASME 2022 14th International Pipeline Conference
, Slifka, A.
, Connolly, M.
, Lucon, E.
, Litschewski, A.
and Uranga, P.
Ductility-driven ranking system for API-grade steels in high pressure gaseous hydrogen transmission pipelines, Proceedings of the ASME 2022 14th International Pipeline Conference
, Calgary, Alberta, CA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935340
(Accessed December 3, 2023)