Filtern
Erscheinungsjahr
Dokumenttyp
- Zeitschriftenartikel (136)
- Beitrag zu einem Tagungsband (46)
- Beitrag zu einem Sammelband (15)
- Vortrag (14)
- Forschungsbericht (7)
- Buchkapitel (2)
- Corrigendum (2)
- Posterpräsentation (2)
- Sonstiges (1)
Sprache
- Englisch (225) (entfernen)
Schlagworte
- Welding (39)
- Residual stresses (31)
- Hydrogen (21)
- Residual stress (19)
- Restraint (17)
- High-strength steels (14)
- Phase transformation (14)
- Hydrogen embrittlement (12)
- Cold cracking (10)
- High-strength steel (10)
Organisationseinheit der BAM
- 9 Komponentensicherheit (62)
- 9.4 Integrität von Schweißverbindungen (59)
- 9.2 Versuchsanlagen und Prüftechnik (27)
- 9.0 Abteilungsleitung und andere (12)
- 8 Zerstörungsfreie Prüfung (5)
- 8.5 Röntgenbildgebung (4)
- 1 Analytische Chemie; Referenzmaterialien (1)
- 1.3 Instrumentelle Analytik (1)
- 5 Werkstofftechnik (1)
- 5.1 Mikrostruktur Design und Degradation (1)
Paper des Monats
- ja (5)
Eingeladener Vortrag
- nein (14)
Carrier gas hot extraction (CGHE) is a commonly applied technique for determination of hydrogen in weld joints using a thermal conductivity detector (TCD) for hydrogen measurement. The CGHE is based on the accelerated hydrogen effusion due to thermal activation at elevated temperatures. The ISO 3690 standard suggests different specimen geometries as well as necessary minimum extraction time vs. temperature. They have the biggest influence on precise hydrogen determination. The present study summarizes the results and experience of numerous test runs with different specimen temperatures, geometries (ISO 3690 type B and small cylindrical samples), and factors that additionally influence hydrogen determination. They are namely specimen surface (polished/as-welded), limited TCD sensitivity vs. specimen volume, temperature measurement vs. effects of PI-furnace controller, as well as errors due to insufficient data assessment. Summarized, the temperature is the driving force of the CGHE. Two different methods are suggested to increase the heating rate up to the desired extraction temperature without changing the experimental equipment. Suggestions are made to improve the reliability of hydrogen determination depended on the hydrogen signal stability during extraction accompanied by Evaluation of the recorded data. Generally, independent temperature measurement with dummy specimens is useful for further data analysis, especially if this data is used for calculation of trapping kinetics by thermal desorption analysis (TDA).
Up to the present, the thermomechanical loads during welding and subsequent cooling under design-specific shrinkage restraint resulting from the interaction between the materials and the structure have often not been taken into consideration approperiately for weldability assessment of components. As compared to previous investigations using small specimens this report presents component weld tests under varying intensities of restraint. Online records of the reaction forces and moments demonstrate in which way the intensity of restraint affects the reaction stresses and moments and their meaning for the evaluation of the load level in welded components.