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

Publikationen: Beitrag in FachzeitschriftKurzmitteilungForschung(peer-reviewed)

Autoren

  • Mahdieh Safyari
  • Thomas Willidal
  • Tomohiko Hojo

Externe Organisationseinheiten

  • voestalpine Böhler Welding Austria GmbH, Kapfenberg
  • Tohoku University

Abstract

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.

Details

OriginalspracheEnglisch
Seiten (von - bis)20676-20683
Seitenumfang8
FachzeitschriftInternational Journal of Hydrogen Energy
Jahrgang47.2022
Ausgabenummer1 June
DOIs
StatusVeröffentlicht - 18 Mai 2022