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Hydrogen trapping in T24 Cr-Mo-V steel weld joints - microstructure effect vs. experimental influence on activation energy for diffusion
- Hydrogen-assisted cracking is a critical combination of local microstructure, mechanical load and hydrogen concentration. Welded microstructures of low-alloyed creep-resistant Cr-Mo-V steels show different hydrogen trapping kinetics. This influences the adsorbed hydrogen concentration as well as the diffusion by moderate or strong trapping. A common approach to describe hydrogen traps is by their activation energy that is necessary to release hydrogen from the trap. In the present study, Cr-Mo-V steel T24 (7CrMoVTiB10-10) base material and TIG weld metal were investigated. Electrochemically hydrogen charged specimens were analyzed by thermal desorption analysis (TDA) with different linear heating rates. The results show two different effects. At first, the microstructure effect on trapping is evident in terms of higher hydrogen concentrations in the weld metal and increased activation energy for hydrogen release. Secondly, it is necessary to monitor the real specimen temperature. AHydrogen-assisted cracking is a critical combination of local microstructure, mechanical load and hydrogen concentration. Welded microstructures of low-alloyed creep-resistant Cr-Mo-V steels show different hydrogen trapping kinetics. This influences the adsorbed hydrogen concentration as well as the diffusion by moderate or strong trapping. A common approach to describe hydrogen traps is by their activation energy that is necessary to release hydrogen from the trap. In the present study, Cr-Mo-V steel T24 (7CrMoVTiB10-10) base material and TIG weld metal were investigated. Electrochemically hydrogen charged specimens were analyzed by thermal desorption analysis (TDA) with different linear heating rates. The results show two different effects. At first, the microstructure effect on trapping is evident in terms of higher hydrogen concentrations in the weld metal and increased activation energy for hydrogen release. Secondly, it is necessary to monitor the real specimen temperature. A comparison between the adjusted heating rate and the real specimen temperature shows that the calculated activation energy varies by factor two. Thus, the trap character in case of the base material changes to irreversible at decreased temperature. Hence, the effect of the experimental procedure must be considered as well if evaluating TDA results. Finally, realistic temperature assessment is mandatory for calculation of activation energy via TDA.…
Autor*innen: | Michael RhodeORCiD, Tobias MenteORCiD, E. Steppan, Thomas KannengießerORCiD, J. Steger |
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Dokumenttyp: | Zeitschriftenartikel |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | Welding in the World |
Jahr der Erstveröffentlichung: | 2018 |
Organisationseinheit der BAM: | 9 Komponentensicherheit |
9 Komponentensicherheit / 9.4 Integrität von Schweißverbindungen | |
Herausgeber (Institution): | International Institute of Welding |
Verlag: | Springer |
Verlagsort: | Berlin, Heidelberg |
Jahrgang/Band: | 62 |
Ausgabe/Heft: | 2 |
Erste Seite: | 277 |
Letzte Seite: | 287 |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten | |
Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Angewandte Physik | |
Freie Schlagwörter: | Creep-resistant steel; Diffusion; Hydrogen assisted cracking; Microstructure; Thermal desorption analysis; Welding |
Themenfelder/Aktivitätsfelder der BAM: | Chemie und Prozesstechnik |
Energie | |
Material | |
Material / Degradation von Werkstoffen | |
DOI: | 10.1007/s40194-017-0546-6 |
ISSN: | 0043-2288 |
ISSN: | 1878-6669 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 19.03.2018 |
Referierte Publikation: | Ja |
Datum der Eintragung als referierte Publikation: | 26.04.2018 |