Hydrogen embrittlement testing facilities deliver impact together

Hydrogen embrittlement is an effect which may reduce the ductility, toughness and fatigue life of certain steels when hydrogen is present – this could potentially cause a pipeline containing hydrogen to fail under conditions where it otherwise would not.

For steel pipelines in the gas transmission sector to be used for the transportation of hydrogen, the problem of hydrogen embrittlement needs to be understood and quantified. One of the challenges in quantifying the impact of hydrogen on material properties is that it is heavily dependent on the material in question – including the manufacturing process, the presence of defects, and the welding procedure.

This means that hydrogen may have a large impact on a particular pipeline steel, and negligible impact on another. Therefore, testing must be performed on samples of pipe from real pipelines to understand the impacts for existing infrastructure.

Future Fuels CRC Research into hydrogen embrittlement

Within the Future Fuels CRC, amongst a wide range of research efforts across the hydrogen value chain, five research streams were developed to understand the impact of hydrogen on the material properties of steel pipelines:

1. Hydrogen diffusion
2. Fatigue crack growth
3. Crack formation and fracture initiation
4. Propagating fracture
5. Pipeline welds

These five topics were investigated with a combination of laboratory-scale and full-scale experiments. The aim of the research was to develop models that would predict the performance of pipeline steels and can be used in pipeline design and calculation of the safe operational envelope. The research programme focused on enabling hydrogen injection in lean blends, higher hydrogen blends and pressures, and pure hydrogen service.

The Future Fuels CRC funded the University of Wollongong to establish Australia’s only facility to characterise line pipe steels exposed to high-pressure, gaseous hydrogen. The H2SAFE(TI) Lab (the Hydrogen Structural Assessment of Future Energy Transport Infrastructure Laboratory) has been established at the University of Wollongong and is currently one of the few facilities in the world to have this capability.

The laboratory centralises testing of hydrogen’s effect on steels, including permeation testing, high strain rate testing and fatigue testing of pipe samples from existing pipelines in Australia’s transmission network. Researchers and industry can explore the limits of existing pipeline networks for their maximum potential to transport pressurised hydrogen/methane blends.

The laboratory has also served as a springboard for new projects requiring mechanical testing of specimens exposed to hydrogen gas and is also critical to the development of fracture control models which will be incorporated in future revisions of the Hydrogen Pipeline Systems Code of Practice (and ultimately Australian Standards).

Pressurised hydrogen laboratory testing undertaken in the laboratory was instrumental in providing the basis for the APA Group’s announcement confirming the technical feasibility of converting a 43-kilometre section of the Parmelia Gas Pipeline in Western Australia to carry 100% hydrogen.

In addition to the H2SAFE(TI) lab, a parallel research programme was established at the University of Queensland to perform similar testing on pipe samples, using an alternative method of introducing hydrogen into the steel material. This method uses an electro-chemical ‘hydrogen charging’ technique as a proxy for high-pressure gaseous hydrogen, which has the potential to simplify and reduce the cost of testing but comes with different challenges and uncertainties to the testing in gaseous hydrogen.

The Future Fuels CRC has facilitated testing of samples from the same pipeline at both the University of Queensland and the University of Wollongong H2SAFE(TI) lab. As at March 2025, the results from the two laboratories are in the process of being compared, to address any uncertainties in translating the results of small-scale testing to real-world pipeline conditions.

Research Impact

The work streams have delivered first-of-a-kind capabilities for Australia:

• Deployment of a universal testing machine capable of deforming specimens at very slow strain-rates in a high-pressure hydrogen environment.

• Design and fitting of a pressure vessel capable of creating a hydrogen environment with partial pressures up to 137 bar in a laboratory setting

Case study: March 2025

 

HyResearch record: University of Wollongong
Deployment of the SAFE(TI) Lab for characterising the mechanical properties of line-pipe steels exposed to high-pressure gaseous H2
Development of a new fracture propagation model – HyResearch: Australian Hydrogen R&D Portal

HyResearch record: University of Queensland:
Hydrogen embrittlement of pipeline steels, subcritical crack growth and critical crack growth – HyResearch: Australian Hydrogen R&D Portal
Hydrogen and pipeline steels: orientation dependence of fracture toughness – HyResearch: Australian Hydrogen R&D Portal
Feasibility of the use of gas phase inhibition of hydrogen embrittlement in gas transmission pipelines carrying hydrogen – HyResearch: Australian Hydrogen R&D Portal