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Unveiling the effect of MnO/SiO2 ratios on the viscosity and structure of mold fluxes for high-Mn cryogenic steels.
- Source :
-
Ceramics International . Sep2023:Part B, Vol. 49 Issue 17, p29308-29316. 9p. - Publication Year :
- 2023
-
Abstract
- The serious reaction between Mn in molten steel and SiO 2 in calcium silicate-based mold flux during continuous casting of Al-free high-Mn cryogenic steels could change the mold flux properties and in-mold performance. In this study, the combination of rotating viscometer, FTIR spectroscopy, Raman spectroscopy and O 1s X-ray photoelectron spectroscopy (XPS) was employed to get a deep insight into the effect of the reaction levels characterized by MnO/SiO 2 ratios on the viscosity and structure of mold fluxes. The results exhibit that the transformation of mold flux from Newtonian fluid to non-Newtonian fluid can be reflected by viscosity change with varying rotation speeds. The viscosity decreases continuously with increasing MnO/SiO 2 ratio but the temperature dependence of viscosity decreases at high MnO/SiO 2 ratio. Structural information from FTIR revealed the slag system is mainly a silicate structure. The deconvoluted results of Raman spectra show an increase in NBO/Si, amounts of Q0 ([SiO 4 ]4–) and Q1 ([Si 2 O 7 ]6–) units with increasing MnO/SiO 2 ratio, whereas a decrease in amounts of Q2 ([SiO 3 ]2–) and Q3 ([Si 2 O 5 ]2–) units in the meantime, this indicates the depolymerization of the silicate structure with proceeding of the slag/steel reaction. According to semiquantitative analysis of XPS spectra, the relative proportion of bridge oxygen (O0) decreases at the cost of non-bridged oxygen (O–), which suggests that the silicate structure gradually depolymerizes. The structural analysis supports the change of viscous behavior of mold flux with slag/steel reaction. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02728842
- Volume :
- 49
- Issue :
- 17
- Database :
- Academic Search Index
- Journal :
- Ceramics International
- Publication Type :
- Academic Journal
- Accession number :
- 166740390
- Full Text :
- https://doi.org/10.1016/j.ceramint.2023.06.225