Viscosity detection and the estimation model of fluorine-containing mold flux for continuous casting
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摘要: 采用旋轉柱體法對不同類型的含氟連鑄保護渣黏度進行檢測,并基于Arrhenius方程通過非線性回歸分析建立了新的黏度預測模型,分析了組分變化對黏度的影響。結合模型計算和實驗檢測,建立了CaF2?Na2O?Al2O3?CaO?SiO2?MgO渣系的等黏度圖。結果表明,與傳統的含氟連鑄保護渣黏度預測模型相比,該模型計算的偏差在10%以內,當渣中w(CaF2)超過20%時,偏差逐漸增大,主要由于氟化物揮發造成爐渣成分變化,最終黏度實測值與爐渣初始成分不符,造成模型無法對黏度有效預測。此外,研究發現,CaF2的增加能顯著降低爐渣黏度,而Al2O3和Na2O對黏度的影響受CaF2含量的限制。當w(CaF2)>17%,爐渣黏度隨Al2O3含量增加而減小,當w(CaF2)<17%,Al2O3的增加使爐渣黏度顯著增大;當w(CaF2)>11.5%,爐渣黏度隨Na2O含量增加顯著下降,當w(CaF2)<11.5%,Na2O含量變化對黏度的影響并不明顯。此外,該等黏度圖表明低黏度區w(CaF2)接近14%。通過調整等黏度圖中各組分比例,可以改善保護渣的黏度和流動性,供鋼鐵工業應用。Abstract: Mold flux plays a significant role in the continuous casting of steel. Especially, the viscosity (or its inverse, fluidity) of mold flux is a key parameter for industrial applications to aid in product quality. In this paper, viscosities of different types of fluorine-containing continuous casting mold fluxes were first measured by the rotating cylinder method, and then a new viscosity estimation model was established based on the Arrhenius equation combined with nonlinear regression analysis to analyze the influence of component changes on the viscosity. Combining model calculation and experimental measurement, an iso-viscosity diagram of the CaF2–Na2O–Al2O3–CaO–SiO2–MgO slag system was also created. It is found that deviation within 10% is calculated using the model in this study compared with the traditional viscosity estimation models of different types of fluorine-containing continuous casting mold fluxes but gradually increases when the w(CaF2) of slag exceeds 20%, mainly due to the change of slag composition caused by fluoride volatilization. Finally, the measured value cannot correspond to the composition of the initial slag, and the model cannot give an accurate estimated value. It is also found that an increase of CaF2 can significantly reduce viscosity, whereas, the effect of Al2O3 and Na2O on viscosity is restricted by CaF2 content. When w(CaF2) > 17%, the viscosity of slag decreases with increasing w(Al2O3), and when w(CaF2) < 17%, the viscosity of slag increases significantly with increasing w(Al2O3). When w(CaF2) > 11.5%, the viscosity of the slag system decreases significantly with increasing w(Na2O) mass. When w(CaF2) < 11.5%, the effect of Na2O on viscosity is not obvious. In addition, the diagram shows that the mass fraction of CaF2 in the low viscosity area is nearly 14%. This shows that the viscosity and fluidity of mold flux can be improved by adjusting the component ratio in this iso-viscosity diagram for applications in the steel industry.
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表 1 含氟保護渣成分范圍(質量分數)
Table 1. Composition of fluorine-containing mold flux
% CaF2 M Na2O Al2O3 MgO 4–20 0.6–1.2 3–12 2–12 0–12 表 2 連鑄保護渣組成(質量分數)
Table 2. Components of mold fluxes for continuous casting
% Slag CaO SiO2 Al2O3 CaF2 Na2O MgO M Slag CaO SiO2 Al2O3 CaF2 Na2O MgO M C1 24.6 22.3 11.2 19 11.7 11.2 1.1 C24 33.7 37.4 7.2 12.4 3.1 6.2 0.9 C2 34.0 30.9 10.5 17.8 4.7 2.1 1.1 C25 27.6 30.7 7.6 13 8.1 13 0.9 C3 35.1 32.0 11.2 7.8 11.7 2.2 1.1 C26 33.8 37.5 7.6 13 8.1 0 0.9 C4 35.1 31.9 10.5 7.3 4.7 10.5 1.1 C27 30.7 34.1 7.6 13 8.1 6.5 0.9 C5 32.8 29.8 4.5 19 11.7 2.2 1.1 M1 23.4 38.3 6.2 12.9 18.8 0.5 0.6 C6 32.9 29.9 4.2 17.8 4.7 10.5 1.1 M2 17.5 40.0 5.2 14.5 21.5 1.3 0.4 C7 33.9 30.9 4.5 7.8 11.7 11.2 1.1 M3 20.1 34.4 4.8 14.3 26.4 0 0.6 C8 42.8 38.9 4.2 7.3 4.7 2.1 1.1 M4 19.4 36.6 18.0 17.2 8.8 0 0.5 C9 23.0 32.9 11.2 19 11.7 2.2 0.7 M5 32.6 31.2 5.3 8.0 22.9 0 1.0 C10 23.3 33.2 10.5 17.8 4.7 10.5 0.7 M6 22.5 42.2 10.4 10.7 13.0 1.3 0.5 C11 23.9 34.2 11.2 7.8 11.7 11.2 0.7 M7 21.5 33.2 3.7 15.4 25.7 0.5 0.6 C12 31.0 44.4 10.5 7.3 4.7 2.1 0.7 M8 22.7 38.6 6.3 13.5 18.9 0 0.6 C13 22.1 31.5 4.5 19 11.7 11.2 0.7 M9 22.3 35.0 8.9 16.5 17.3 0 0.6 C14 29.3 41.9 4.2 17.8 4.7 2.1 0.7 M10 20.4 34.0 4.3 17.9 23.4 0 0.6 C15 30.4 43.4 4.5 7.8 11.7 2.2 0.7 M11 13.8 32.0 3.5 20.2 27.1 3.5 0.4 C16 30.2 43.1 4.2 7.3 4.7 10.5 0.7 P1 39 39 0 13 8.4 1.6 1.0 C17 35.3 29.5 7.6 13 8.1 6.5 1.2 P2 39 39 0 13 3.6 6.4 1.0 C18 24.3 40.5 7.6 13 8.1 6.5 0.6 P3 41 41 0 13 3.6 1.6 1.0 C19 28.1 31.3 13 13 8.1 6.5 0.9 P4 39 39 0 7 8.4 6.4 1.0 C20 33.3 36.9 2.2 13 8.1 6.5 0.9 P5 42 42 0 7 8.4 1.6 1.0 C21 26.6 29.6 7.6 21.6 8.1 6.5 0.9 P6 42 42 0 7 3.6 6.4 1.0 C22 34.8 38.7 7.6 4.3 8.1 6.5 0.9 P7 44 44 0 7 3.6 1.6 1.0 C23 27.5 30.5 8.0 13.6 13.6 6.8 0.9 P8 30 42 0 13 8.4 6.4 0.7 P9 34 48 — 13 3.6 1.6 0.7 S1 33.5 53.0 — 13.5 — — 0.6 P10 34 41 — 15 6 4 0.85 S2 32.9 47.8 — 19.3 — — 0.7 P11 35 41 — 10 10 4 0.85 S3 33.1 46.9 — 20.0 — — 0.7 P12 39 45 — 10 6 0 0.85 S4 30.8 37.8 — 31.4 — — 0.8 P13 35 41 — 10 6 8 0.85 S5 27.0 30.4 — 42.6 — — 0.9 P14 37 43 — 10 6 4 0.85 S6 33.0 39.6 — 27.4 — — 0.8 P15 42 38 — 10 6 4 1.1 S7 33.2 38.6 — 28.2 — — 0.9 表 3 黏度參數分析
Table 3. Viscosity controlling parameters
Slag lnA B Slag lnA B Slag lnA B C1 ?12.1166 16750.76 C10 ?11.1663 15523.76 C19 ?11.6419 16899.20 C2 ?11.1521 15331.25 C11 ?11.4069 16399.51 C20 ?10.5736 14696.67 C3 ?11.4827 16323.80 C12 ?11.9045 19019.28 C21 ?9.26063 11473.14 C4 ?11.2338 16106.31 C13 ?10.7114 13670.59 C22 ?11.3388 18048.45 C5 ?10.9666 13904.19 C14 ?11.1896 15932.56 C23 ?10.4814 13697.65 C6 ?11.1806 14859.89 C15 ?11.4391 17000.89 C24 ?17.2362 25991.79 C7 ?11.3522 15328.48 C16 ?11.1312 16491.46 C25 ?10.5812 14320.87 C8 ?11.3635 16421.96 C17 ?14.9610 21103.44 C26 ?13.0682 18316.60 C9 ?10.9992 14722.03 C18 ?12.8972 19711.71 C27 ?10.7828 13602.93 259luxu-164 -
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