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Solidification Behavior of CaO–SiO 2 –Al 2 O 3 Mold Fluxes Containing MgO and Low TiO 2 Content Using Single Hot Thermocouple Technique (SHTT): Continuous‐Cooling‐Transformation (CCT) and Viscosity Analysis
Author(s) -
dos Reis Silva Daniel,
Vilela Antônio Cezar Faria,
Heck Nestor Cezar,
Heller HansPeter,
Volkova Olena
Publication year - 2018
Publication title -
steel research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.603
H-Index - 49
eISSN - 1869-344X
pISSN - 1611-3683
DOI - 10.1002/srin.201700246
Subject(s) - melilite , crystallization , materials science , thermocouple , scanning electron microscope , analytical chemistry (journal) , viscometer , mold , viscosity , cooling curve , continuous cooling transformation , titanium , mineralogy , metallurgy , chemical engineering , composite material , microstructure , chemistry , martensite , chromatography , engineering , spinel , bainite
The effect of MgO and low TiO 2 content on the solidification of CaO–SiO 2 –Al 2 O 3 based mold fluxes is investigated. The crystallization and viscosity behaviors are analyzed using single hot thermocouple technique (SHTT) and rotating viscometer, respectively. Continuous‐cooling‐transformation (CCT) results point to an increase of critical cooling rate (CCR) with increasing MgO content. Conversely, the presence of TiO 2 seems to mitigate the effect of MgO on the crystallization due to the strong glass former characteristic of titanium dioxide. Viscosity measurements show an increase with increasing MgO content in slags containing TiO 2 . Break temperatures ( T br ) are compared to the onset crystallization temperatures from CCT experiments. Scanning electron microscopy (SEM) and X‐ray diffraction (XRD) analysis results indicate the presence of melilite (Al 2 Ca 2 Mg 0.5 O 7 Si 1.5 ) for all samples of mold flux containing both MgO and TiO 2 .