Die Existenz der nichtmetallischen Einschlüsse in der Metallschmelze führt zur Verschlechterung der physikalischen Eigenschaften des gegossenen Stahls. Die im Rahmen des SFB 920 entstandene Arbeit beschäftigt sich hauptsächlich mit der Untersuchung der reaktiven Reinigung und aktiven Filtration der Metallschmelze im Induktionsofen mithilfe der numerischen Strömungsmechanik. Dazu werden im Rahmen der Arbeit neue numerische Simulationsmodelle entwickelt. Die Ergebnisse zeigen, dass die reaktive Reinigung einen ausschlaggebenden positiven Einfluss auf die Entfernung der Einschlüsse aus der Metallschmelze hat, wobei der Reinheitsgrad der Metallschmelze innerhalb einer kurzen Eintauchzeit des kohlenstoffgebundenen Filters ansteigt.
Der in der reinen aktiven Filtration erzielte Reinheitsgrad ist deutlich niedriger als im Falle der reaktiven Reinigung. Des Weiteren befasst sich die Arbeit mit dem Effekt der Turbulenzmodellierung auf die Beschreibung der Schmelzeströmung und der Verteilung der Einschlüsse. Weiterhin stellt die Arbeit ein experimentelles Wassermodell zur Nachbildung der rezirkulierenden Schmelzeströmung im Induktionsofen vor.:Abstract
List of figures
List of Tables
Nomenclature
1 Introduction
2 State of the Art
3 Numerical Model
4 Results
5 Summary and Conclusion
6 Outlook
Bibliography / During the continuous casting, non-metallic inclusions such as deoxidation or reoxidation products may arise in steel melt due to different reactions. These inclusions have to be removed from the melt with the aim of improving the cleanliness of steel products. There are many approaches in continuous casting to enhance inclusion removal from the melt. However, this Phd thesis focuses particularly on inclusion removal by reactive cleaning and active filtration during the melt casting in an induction crucible furnace using ceramic foam filter developed in CRC 920. For this purpose, a numerical model is developed in OpenFOAM in order to simulate the melt flow and reactive cleaning as well as active filtration. Besides the numerical model, an experimental water model are created to validate the capability of the numerical model to predict the recirculating turbulent flow in the induction crucible furnace. The results show that reactive cleaning and the formation of carbon monoxide bubbles, which arise on the inclusions, have a positive impact on the melt cleanliness. Reactive cleaning can improve inclusion removal and enhance the melt cleanliness sufficiently. Based on the results, one can conclude that the rate of inclusion removal in case of reactive cleaning is considerably higher than that in case of active filtration. Furthermore, the results indicate the considerable influence of filter position and filter number on the flow field as well as on the cleaning efficiency in the induction crucible furnace. Moreover, the results shows that turbulence modeling has a considerable impact on the prediction of the melt flow and inclusion dispersion in the induction crucible furnace.:Abstract
List of figures
List of Tables
Nomenclature
1 Introduction
2 State of the Art
3 Numerical Model
4 Results
5 Summary and Conclusion
6 Outlook
Bibliography
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:72447 |
| Date | 15 October 2020 |
| Creators | Asad, Amjad |
| Contributors | Schwarze, Rüdiger, Volkova, Olena, Technische Universität Bergakademie Freiberg |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0022 seconds