University of Oulu

Shu, Q., Li, Q., & Fabritius, T. (2019). Effects of MoO3 + C on Crystallization and Radiative Heat Transfer of CaO–SiO2–B2O3-Based Glassy Fluoride-Free Mold Fluxes. Metals, 9(5), 516.

Effects of MoO₃ + C on crystallization and radiative heat transfer of CaO–SiO₂–B₂O₃-based glassy fluoride free mold fluxes

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Author: Shu, Qifeng1,2; Li, Qiangqi2; Fabritius, Timo1
Organizations: 1Process Metallurgy Research Unit, University of Oulu, FI-90014 Oulu, Finland
2University of Science and Technology Beijing, Beijing 100083, China
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 3.6 MB)
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Language: English
Published: Multidisciplinary Digital Publishing Institute, 2019
Publish Date: 2019-09-18


The fluorine in traditional mold fluxes could be harmful in steel-plant environments. Accordingly, fluoride-free mold fluxes have received great attention in recent years. In this work, a method to adjust the crystallization and radiative heat transfer of fluoride-free mold fluxes is proposed. MoO₃ and C mixtures (mass ratio: 4:1) were added into CaO–SiO₂–B₂O₃-based mold fluxes and produced MoB, Mo₂CB and Mo₂C foreign particles. The influences of foreign particles on the radiation of glassy CaO–SiO₂–B₂O₃-based mold fluxes were investigated measuring the transmissivity of a glassy disk for light in the wavenumber range of 300 to 2500 nm. It was found that transmissivity in all wavenumber ranges were reduced and extinction coefficients were enhanced by the scattering of foreign particles. The effect of foreign particles on crystallization (devitrification) of bulk glassy CaO–SiO₂–B₂O₃-based mold fluxes was also investigated. The crystallization mechanism of glassy mold fluxes disks is mainly surface crystallization. The introduction of foreign particles induced heterogeneous nucleation and the crystallization mechanism of the bulk sample with MoO₃% = 2% changed into bulk crystallization.

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Series: Metals
ISSN: 2075-4701
ISSN-E: 2075-4701
ISSN-L: 2075-4701
Volume: 9
Issue: 5
Article number: 516
DOI: 10.3390/met9050516
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
Funding: Financial support from the Academy of Finland for Genome of steel grant (No. 311934) and Natural Science Foundation of China (NSFC contract no.51774026) is gratefully acknowledged.
Copyright information: © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (