Inclusion Motion under a Swirl Flow in the Continuous Casting Process and Wire Feeding in the Induction Furnace
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
The thesis includes the studies of two phenomena related to continuous casting. One subject is the inclusion motion in the submerged entry nozzle (SEN) and mold when using a swirl flow. The swirl flow is generated in a SEN by using an electromagnetic swirl flow generator (EMSFG). The other subject is focused on FeSiRE particles (powder) that are added into the molten steel by using a wire feeding method, which in the future could be used in a continuous casting mold.
Firstly, two kinds of a full type and a half type EMSFG were designed based on mathematical modeling. Then, the distributions of the magnetic flux intensity and the Lorentz force were obtained for two types of EMSFG devices. Based on the results of the Lorentz force, the flow field, temperature field and inclusion motion in the SEN and the mold were studied by using a full type and a half type EMSFG. Moreover, a comparison from the above aspects was investigated between a full type EMSFG and a half type EMSFG. In addition, the effect of different inclusion parameters such as the densities, sizes and boundary conditions, on the inclusion behavior was studied. It was found that light Al2O3 inclusion moves towards the rotational center by a centrifugal force and that a swirl flow prevents nozzle clogging. The heavy CeO2 inclusion more or less moves outwards towards the SEN wall and they may stick to the wall. It was also found that the inclusion separation to a mold meniscus increased and that the inclusions being trapped into a solidified shell decreased when using a swirl flow compared to when not using a swirl flow.
A study of a wire feeding into molten steel in an induction furnace was done to determine the potential to implement wire feeding into a mold in the future. A major difference compared to a traditional solid wire is that the wire contains particles (powder). Firstly of all, the wire melting behavior in the molten steel was studied. More specially, the influence of the different wire materials (aluminum, copper and 316L stainless steel wires) on the dissolution time in the molten steel was modeled. Moreover, these simulation results were compared to experimental results. In addition, the FeSiRE particle (powder) motion in the induction furnace was also simulated. The results showed that the copper wire is more suitable to apply in the continuous casting mold when a small addition and a lower wire feeding speed are used. Conversely, if a large amount and a higher feeding speed are needed, the aluminum wire may be recommended for injections in the mold. The results also indicated that the thermal properties of particle (powder) have an influence on the wire melting behavior in the molten steel.
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. , ix, 71 p.
inclusion motion, swirl flow, rotating magnetic field, electromagnetic swirl flow generator, full type, half type, submerged entry nozzle, mold, wire feeding, melting behavior, FeSiRE particle (powder) motion, induction furnace
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-175999ISBN: 978-91-7595-736-4OAI: oai:DiVA.org:kth-175999DiVA: diva2:865167
2015-11-27, Sal D3, Lindstedtsvägen 5, KTH, Stockholm, 10:00 (English)
Louhenkilpi, Seppo, Professor
Jönsson, Pär, Professor
QC 201501022015-11-022015-10-272015-11-02Bibliographically approved
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