Lokaler Wärmeübergang in der Kokille einer Brammenstranggießanlage auf Basis von Temperaturmessungen mittels Fiber-Bragg-Gitter

Translated title of the contribution: Local heat transfer in the mold of a continuous slab caster based on temperature measurements via a Fiber Bragg Grating

Julian Laschinger

Research output: ThesisMaster's Thesis

Abstract

The phenomena and processes in the mold of a continuous caster have a decisive impact on product quality. Depending on the chemical composition, the solidification behavior of the melt in the mold changes. Accordingly, the properties of the casting powder used must be adapted to ensure adequate lubrication and heat transfer for the respective melt. In order to be able to make qualitative statements regarding the processes in the mold and to ensure process monitoring in the mold, a comprehensive temperature measurement system is required in the mold. This also makes it possible to quantify the heat removed locally and to draw conclusions about the solidification behavior of the melt in question. In the course of this work, heat transfer coefficients (HTC) for various carbon equivalents are to be calculated on the basis of temperature measurements from the continuous casting process. These can be used as boundary conditions in numerical calculations. For this purpose, the broadside of a continuous slab caster of voestalpine Stahl GmbH in Linz was instrumented with a fiber-optic temperature measurement system called fiber Bragg grating. This provides a higher density of temperature measurement points than the thermocouples normally used, which is due to the simpler measurement setup. Based on these temperature measurement values, the locally removed heat was quantified using the calculation methodology recorded in the thesis. This distribution of dissipated heat flux densities over the entire broadside of the plant was then used as a boundary condition for the solidification calculation of selected melts. The software calcosoft-2D was used for this purpose. The thermophysical data for the chemical composition of the melts originated from in-house software. The heat transfer coefficients could be calculated from the heat flux densities, the mold surface temperatures and the strand surface temperatures. This showed that high-carbon melts have the highest heat transfer coefficients, especially below the meniscus. Hyper-peritectic grades show the lowest HTCs and the most uniform decrease over the mold height. These results are in good agreement with the expectations which can be met on the basis of the respective casting powder properties. This work lays a foundation for the determination of reliable heat transfer coefficients in the mold as a function of chemical composition.
Translated title of the contributionLocal heat transfer in the mold of a continuous slab caster based on temperature measurements via a Fiber Bragg Grating
Original languageGerman
QualificationDipl.-Ing.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Bernhard, Christian, Supervisor (internal)
Award date21 Oct 2022
Publication statusPublished - 2022

Bibliographical note

embargoed until 31-08-2027

Keywords

  • Continuous casting
  • Mold
  • Heat transfer
  • Heat transfer coefficient

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