2015-Sustainable Industrial Processing Summit
SIPS 2015 Volume 2: Gudenau Intl. Symp. / Iron and Steel Making
| Editors: | Kongoli F, Kleinschmidt G, Pook H, Ohno K, Wu K |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2015 |
| Pages: | 340 pages |
| ISBN: | 978-1-987820-25-6 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
< CD shopping page
Effect of Mold Flux Properties on the Thin Slab Continuous Caster of High Carbon Steel
Jun-Yong Park1; Il Sohn2;1YONSEI UNIVERSITY, Seoul, Korea (Republic of [South] Korea); 2YONSEI UNIVERSITY MATERIALS SCIENCE AND ENGINEERING, Seoul, Korea (Republic of [South] Korea);
Type of Paper: Regular
Id Paper: 468
Topic: 2
Abstract:
Mold flux is infiltrated between the solidified shell and the water-cooled copper mold and plays an important role in the continuous casting of steel. The mold flux can protect the molten steel surface from the atmosphere, absorb inclusions during the process, thermally insulate, control the heat transfer between the shell and the mold and provide sufficient lubrication between the solidified shell and the water-cooled copper mold. Controlling heat transfer through the mold flux is important since it has such a significant effect on the surface quality of the steel. The heat can be transported by two mechanisms; conduction and radiative heat transfers. The overall thermal resistance between the copper mold and the solidified steel shell consists of conduction and radiation resistances caused by infiltrated mold flux film and interfacial resistance between the mold and the flux. Because radiative heat transfer can be reduced by crystalline phase which lowers the transmissivity of the mold fluxes by scattering the radiation from the shell, crystallization behavior of fluxes is very important for heat transfer, and also, the interfacial resistance between the mold and the solidified slag can be increased with the formation of more air gaps during the solidification of the mold flux. In this study, therefore, crystallization behavior of mold fluxes was identified using the CLSM (confocal laser scanning microscope) and a CCT diagram. As for radiative heat transfer, UV-VIS-NIR spectrophotometer was introduced to analyze the transmissivity and the reflectivity of the fluxes. Also, the interfacial resistance between the copper mold and molten fluxes was studied using a copper disc mold simulator and thermal conductivity of the liquid fluxes was measured using a hot-wire method. In particular, crystallization behavior presented in the CCT diagram and the thermal conductivity were correlated with the molten flux structure using FTIR (Fourier transform infrared) analysis of the as-quenched flux specimens. Utilizing the fundamental properties of fluxes, trials in commercial thin slab casters with the modified mold flux were implemented with promising results.