63413 2025 eng 1 15 article Springer Berlin 1 -- -- -- Green hydrogen has become an essential energy carrier to achieve a climate-neutral economy. The production, storage, transport and usage of green hydrogen require safe and sustainable facilities and systems. The present contribution provides a procedure guideline to investigate the compatibility of steel welds for pressurised gaseous hydrogen applications under quasi-static mechanical loads, utilising the slow strain rate test and hollow specimen technique. Exemplarily, a weld of the low-alloyed steel P355NL1 was investigated and compared to an X65 weld. The results indicate that the base metal exhibits a higher ductility than the weld metal for both steels. Generally, hydrogen-exposed specimens exhibited a reduced strain, as compared to reference specimens. The hydrogen degradation, evaluated by the hydrogen embrittlement index, was more pronounced in the weld metal compared to the base P355NL1 material, whereas the X65 exhibited a larger hydrogen degradation of the base material than in the weld metal. Fractographic analysis of the test specimens revealed that hydrogen causes a transition from ductile to brittle features. Generally, the results of this study indicate a mild but significant degradation of the mechanical properties in terms of the ductility of the welds in the respective pressurised hydrogen atmosphere. Welding in the world 0043-2288 10.1007/s40194-025-02074-7 urn:nbn:de:kobv:b43-634138 true journal-article https://creativecommons.org/licenses/by/4.0 crossref doi-import 17.06.2025 https://nbn-resolving.org/urn:nbn:de:kobv:b43-634647 Creative Commons - CC BY - Namensnennung 4.0 International Nikanor Shikomba Thomas Böllinghaus Florian Konert Oded Sobol Sergio Blasón Gonzalez Idehai Olayemi Ohijeagbon Eike Krafft Thorsten Staudt eng uncontrolled Hydrogen-assisted cracking eng uncontrolled Welded joint eng uncontrolled Slow strain rate test eng uncontrolled Hollow Specimen eng uncontrolled Structural steel Angewandte Physik 9 Komponentensicherheit 9.1 Komponenten für Energieträger Energie Verlagsliteratur Datei für die Öffentlichkeit verfügbar ("Open Access") Wissenschaftliche Artikel der BAM 9.0 Abteilungsleitung und andere Wasserstoff Bundesanstalt für Materialforschung und -prüfung (BAM) https://opus4.kobv.de/opus4-bam/files/63413/s40194-025-02074-7 (2).pdf