As part of Task 2.2 and 2.3 of CANDHy Work Package 2 (WP2) a full review of the state of the art of the standards, codes but also a literature review on testing of non-steel metallic material in hydrogen environment was performed.
Current standards cover steel materials and there is a need to provide additional information for non-steel metallic materials and components of the distribution grid. Screening tests are the most common tests to evaluate the behaviour of materials in hydrogen and mainly tensile and SSR tests were performed on non-steel metallic materials. Therefore, fracture and fatigue tests providing data on crack initiation and growth quasi-static or cyclic loading would be necessary to completely understand the effect of hydrogen gas.
Following this work, fracture tests such as KIH test, fracture toughness, SSR and C-ring and fatigue test such FCGR should be conducted on materials such as ductile and gray cast iron, copper, aluminium, brass and lead. Due to the small material thicknesses of the non-steel pipes used in the distribution gas grid, testing like KIH test, fracture toughness and FCGR might not be possible because bigger specimens are needed to obtain valid results; therefore, C-ring and SSR on notched specimens could be performed to study the material behavior and the sensitivity to hydrogen in presence of a notch in H2.
