A new CaO–Al₂O₃–Ce₂O₃–MgO–SiO₂ tundish flux for rare earth steel has been presented in the current study based on the phase diagram and iso-activity diagram. The effect of Ce₂O₃ content and w(CaO)/w(Al₂O₃) on the melting temperature, viscosity, and crystalline phase was investigated. Results indicated that with the increasing Ce₂O₃ content and w(CaO)/w(Al₂O₃), the viscosity and melting temperature decreased, whereas the breaking temperature exhibited the opposite tendency. When the Ce₂O₃ content increased from 5 to 9 wt%, the crystalline phase began to precipitate. The Ce₂O₃ content further increases to 17 wt%, the crystalline phase changed from CaCeAl₃O₇ to CaCeAl₃O₇ and CeAlO₃. The crystalline phase changed from CaCeAl₃O₇ to Ca₃Al₂O₆, CaCeAl₃O₇, and MgO as the w(CaO)/w(Al₂O₃) increased from 0.9 to 1.3. The best range of the compositions of the low-reactivity tundish flux was w(CaO)/w(Al₂O₃) = 1–1.3, MgO = 5 wt%, SiO₂ = 5 wt%, Ce₂O₃ = 0–10 wt%. The melting temperature was in the range of 1300–1320 °C, and the viscosity at 1500 °C was in the range of 0.18–0.45 Pa·s. The compositions were suitable for the development of sustainable metallurgy.

Graphical Abstract

中文翻译：

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一种新型稀土钢中间包助熔剂的设计与流动性研究

基于相图和等活度图，本研究提出了一种新的稀土钢CaO-Al ₂ O ₃ -Ce ₂ O ₃ -MgO-SiO _{2中间包熔剂。}研究了Ce ₂ O ₃含量和w (CaO)/ w (Al ₂ O ₃ ) 对熔融温度、粘度和晶相的影响。结果表明，随着 Ce ₂ O ₃含量和w (CaO)/ w (Al ₂ O ₃)，粘度和熔融温度降低，而断裂温度则呈现相反的趋势。当 Ce ₂ O ₃含量从 5 wt% 增加到 9 wt% 时，结晶相开始沉淀。Ce ₂ O ₃含量进一步增加到17 wt%，晶相由CaCeAl ₃ O ₇变为CaCeAl ₃ O ₇和CeAlO ₃。晶相由 CaCeAl 3 _O 7_转变为 Ca ₃ Al ₂ O ₆、CaCeAl ₃ O ₇和 MgO(CaO)/ w (Al ₂ O ₃ ) 从 0.9 增加到 1.3。低活性中间包熔剂的最佳组成范围为w (CaO)/ w (Al ₂ O ₃ ) = 1-1.3, MgO = 5 wt%, SiO ₂  = 5 wt%, Ce ₂ O ₃  = 0 –10 重量%。熔融温度在 1300-1320 ℃范围内，1500 ℃时的粘度在 0.18-0.45 Pa·s 范围内。该组合物适用于可持续冶金的发展。

图形概要