Material and structural integrity assessment for safe Nordic hydrogen transportation infrastructure

The MatHias project addresses technological and safety barriers to transport and storage of hydrogen via pipeline infrastructure in the Nordic countries This is a key challenge in the emerging hydrogen economy. A key threat to the safety of hydrogen pipelines is the so-called hydrogen embrittlement phenomenon, caused by atomic hydrogen ingress into the steel making the pipelines prone to brittle fracture. Low (freezing) temperatures that prevail in the Nordic region may further increase the embrittlement. Therefore, the project aims to provide a collection of databases for material selection and development against low temperature and hydrogen embrittlement. The research questions that will be addressed are: 1) Mapping the mechanism(s) of low-temperature hydrogen embrittlement in pipeline steels, 2) experimental and numerical assessment of the phenomenon and its use in pipeline design, and 3) Validation of design protocols for hydrogen pipelines. The research organizations VTT (F), Oulu University (F), Uppsala University (S), SINTEF (N) and NTNU (N) will work together with the industry companies SSAB (F), Equinor (N), Gasgrid Finland (F) and Nordion Energi (S).

Pipelines provide the most feasible option for regional and inter-regional large-scale transport and storage of pressurized hydrogen gas. A key threat to the safety of hydrogen pipelines is the so-called hydrogen embrittlement phenomenon, caused by hydrogen ingress into the steel making the pipelines prone to brittle fracture. Low (freezing) temperatures that prevail in the Nordic region may further increase the embrittlement. It remains a scientific challenge to understand the combined influence of low temperature and hydrogen on the mechanical properties and fracture resistance of pipeline steels. This knowledge is required for safe design of hydrogen pipeline infrastructure in the Nordic countries. In close cooperation with industrial partners in the Nordic hydrogen value chain, the Norwegian part of the MatHias project will contribute to: 1) Identifying, and bench marking a matrix of vintage and modern pipeline steels, 2) characterize the steels by applying state-of-the-art test methods in relevant environmental conditions, 3) build a material database with mechanical properties and microstructural features as a function of hydrogen and temperature and 4) develop a predictive structural integrity assessment tool that will assist pipeline operators to select appropriate steels, assess lifetime and schedule maintenance for Nordic hydrogen pipelines. The research activities will be kept record of, and the outcome monitored constantly and verified where applicable. By the end, a joint review of the project work will be performed by all participants, and a common testing and modelling protocol for Nordic hydrogen pipelines will be drafted. The protocol will provide a basis for a Nordic design and maintenance standard for hydrogen pipelines and provide reference for research-based policy making for Nordic hydrogen valleys in the future (by 2030 and 2040).