Hydrogen trapping and desorption affected by ferrite grain boundary types in shielded metal and flux-cored arc weldments with Ni addition

Masoud Moshtaghi, Bernd Loder, Mahdieh Safyari, Thomas Willidal, Tomohiko Hojo, Gregor Karl Mori

Publikation: Beitrag in FachzeitschriftArtikelForschungBegutachtung


Hydrogen trapping behavior and diffusion induced by the microstructure of shielded metal and flux-cored arc weldments (SMAW and FCAW) were characterized using a combination of high-resolution microstructural characterization methods, hydrogen trap site studies, and a modeling technique. H trapping by HAGBs that was found by TDS was confirmed by NanoSIMS with a cryogenic stage. Cellular automaton modeling results showed that in grain sizes smaller than a critical grain size, the hydrogen diffusion coefficient decreases with decreasing grain size, indicating that H trapping dominates short-circuit diffusion mechanism along high-angle grain boundaries (HAGBs). These results firstly show that smaller grain size and high HAGB density in the FCAW specimen results in a lower H diffusion coefficient and higher density of relatively strong HAGB traps, and a lower total desorbed hydrogen content in the FCAW specimen. Also, it was suggested that the fraction of acicular ferrite grains can define the HAGB content in the alloy, and can be a determinant factor in the behavior of weldments in H-containing media.
Seiten (von - bis)20676-20683
FachzeitschriftInternational Journal of Hydrogen Energy
PublikationsstatusVeröffentlicht - 18 Mai 2022

Bibliographische Notiz

Funding Information:
This study was supported by the grant with a number of P012-01-065 under the Industry-Academia Collaborative R&D Program. The authors would like to appreciate voestalpine Böhler Welding Austria GmbH for support and resources. M.M. appreciates Prof. S. Kuramoto, and F. Abbasi for their help with the resources and discussion.

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