Effects of MoO3 + C on Crystallization and Radiative Heat Transfer of CaO–SiO2–B2O3-Based Glassy Fluoride-Free Mold Fluxes

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. MoO&l...

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Main Authors:	Qifeng Shu, Qiangqi Li, Timo Fabritius
Format:	Article
Language:	English
Published:	MDPI AG 2019-05-01
Series:	Metals
Subjects:	fluoride-free mold fluxes radiative heat transfer crystallization particles in glass
Online Access:	https://www.mdpi.com/2075-4701/9/5/516

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spelling	doaj-1e89c9e7aec7435ea40e6eb7a0fbb22e2020-11-25T01:34:05ZengMDPI AGMetals2075-47012019-05-019551610.3390/met9050516met9050516Effects of MoO<sub>3</sub> + C on Crystallization and Radiative Heat Transfer of CaO–SiO<sub>2</sub>–B<sub>2</sub>O<sub>3</sub>-Based Glassy Fluoride-Free Mold FluxesQifeng Shu0Qiangqi Li1Timo Fabritius2Process Metallurgy Research Unit, University of Oulu, FI-90014 Oulu, FinlandUniversity of Science and Technology Beijing, Beijing 100083, ChinaProcess Metallurgy Research Unit, University of Oulu, FI-90014 Oulu, FinlandThe 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. MoO<sub>3</sub> and C mixtures (mass ratio: 4:1) were added into CaO−SiO<sub>2</sub>−B<sub>2</sub>O<sub>3</sub>-based mold fluxes and produced MoB, Mo<sub>2</sub>CB and Mo<sub>2</sub>C foreign particles. The influences of foreign particles on the radiation of glassy CaO−SiO<sub>2</sub>−B<sub>2</sub>O<sub>3</sub>-based mold fluxes were investigated by 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−SiO<sub>2</sub>−B<sub>2</sub>O<sub>3</sub>-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 MoO<sub>3</sub>% = 2% changed into bulk crystallization.https://www.mdpi.com/2075-4701/9/5/516fluoride-free mold fluxesradiative heat transfercrystallizationparticles in glass
collection	DOAJ
language	English
format	Article
sources	DOAJ
author	Qifeng Shu Qiangqi Li Timo Fabritius
spellingShingle	Qifeng Shu Qiangqi Li Timo Fabritius Effects of MoO<sub>3</sub> + C on Crystallization and Radiative Heat Transfer of CaO–SiO<sub>2</sub>–B<sub>2</sub>O<sub>3</sub>-Based Glassy Fluoride-Free Mold Fluxes Metals fluoride-free mold fluxes radiative heat transfer crystallization particles in glass
author_facet	Qifeng Shu Qiangqi Li Timo Fabritius
author_sort	Qifeng Shu
title	Effects of MoO<sub>3</sub> + C on Crystallization and Radiative Heat Transfer of CaO–SiO<sub>2</sub>–B<sub>2</sub>O<sub>3</sub>-Based Glassy Fluoride-Free Mold Fluxes
title_short	Effects of MoO<sub>3</sub> + C on Crystallization and Radiative Heat Transfer of CaO–SiO<sub>2</sub>–B<sub>2</sub>O<sub>3</sub>-Based Glassy Fluoride-Free Mold Fluxes
title_full	Effects of MoO<sub>3</sub> + C on Crystallization and Radiative Heat Transfer of CaO–SiO<sub>2</sub>–B<sub>2</sub>O<sub>3</sub>-Based Glassy Fluoride-Free Mold Fluxes
title_fullStr	Effects of MoO<sub>3</sub> + C on Crystallization and Radiative Heat Transfer of CaO–SiO<sub>2</sub>–B<sub>2</sub>O<sub>3</sub>-Based Glassy Fluoride-Free Mold Fluxes
title_full_unstemmed	Effects of MoO<sub>3</sub> + C on Crystallization and Radiative Heat Transfer of CaO–SiO<sub>2</sub>–B<sub>2</sub>O<sub>3</sub>-Based Glassy Fluoride-Free Mold Fluxes
title_sort	effects of moo<sub>3</sub> + c on crystallization and radiative heat transfer of cao–sio<sub>2</sub>–b<sub>2</sub>o<sub>3</sub>-based glassy fluoride-free mold fluxes
publisher	MDPI AG
series	Metals
issn	2075-4701
publishDate	2019-05-01
description	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. MoO<sub>3</sub> and C mixtures (mass ratio: 4:1) were added into CaO−SiO<sub>2</sub>−B<sub>2</sub>O<sub>3</sub>-based mold fluxes and produced MoB, Mo<sub>2</sub>CB and Mo<sub>2</sub>C foreign particles. The influences of foreign particles on the radiation of glassy CaO−SiO<sub>2</sub>−B<sub>2</sub>O<sub>3</sub>-based mold fluxes were investigated by 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−SiO<sub>2</sub>−B<sub>2</sub>O<sub>3</sub>-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 MoO<sub>3</sub>% = 2% changed into bulk crystallization.
topic	fluoride-free mold fluxes radiative heat transfer crystallization particles in glass
url	https://www.mdpi.com/2075-4701/9/5/516
work_keys_str_mv	AT qifengshu effectsofmoosub3subconcrystallizationandradiativeheattransferofcaosiosub2subbsub2subosub3subbasedglassyfluoridefreemoldfluxes AT qiangqili effectsofmoosub3subconcrystallizationandradiativeheattransferofcaosiosub2subbsub2subosub3subbasedglassyfluoridefreemoldfluxes AT timofabritius effectsofmoosub3subconcrystallizationandradiativeheattransferofcaosiosub2subbsub2subosub3subbasedglassyfluoridefreemoldfluxes
_version_	1725073767623819264

Effects of MoO<sub>3</sub> + C on Crystallization and Radiative Heat Transfer of CaO–SiO<sub>2</sub>–B<sub>2</sub>O<sub>3</sub>-Based Glassy Fluoride-Free Mold Fluxes

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