·20· 工程科学学报，第41卷，第1期 长大于1200nm的红外光的反射率随着晶体粒度的 [4]Zhang P,Wei O C,Wang J Y,et al.Present state of research on 增加而增加，而透过率随晶体粒度的增加而减小，但 heat transfer of casting flux film in continuous casting mold.I fron 是对于含有铁氧化物的保护渣，晶体粒度对光学性 Steel Res,1995,7(4):74 (张平，魏庆成，王家荫，等.连铸结品器中保护渣渣膜传热的 质的影响不大.除了晶体外，固态渣膜中的气孔同 研究现状.钢铁研究学报，1995,7(4)：74) 样对光学性质有影响，Rousseau等发现多孔材料的 [5]Meng Y,Thomas B G.Simulation of microstructure and behavior 光学性质不仅与孔隙度有关[别)，还与气孔尺寸有 of interfacial mold slag layers in continuous casting of steel.ISI 关.在孔隙度一定的情况下，气孔的索特平均直径 mt,2006,46(5):660 越小，多孔介质对中红外光（波长在3~50μm范围 [6]Kashiwaya Y,Cicutti C E,Cramb A W,et al.Development of 内)的反射率越大，这意味着固态渣膜中尺寸分布 double and single hot thermocouple technique for in situ observa- tion and measurement of mold slag crystallization.IS//Int,1998, 均匀的小孔可能会对控制辐射传热起到一定的 38(4):348 作用. [7]Zhou L J,Wang W L,Liu R,et al.Computational modeling of temperature,flow,and crystallization of mold slag during double 3渣膜形成及传热研究的展望 hot thermocouple technique experiments.Metall Mater Trans B, (1)利用双丝法和水冷铜探头法已经可以模拟 2013,44(5):1264 [8]Li J,Wang W L,Wei J,et al.A kinetic study of the effect of 出渣膜的形成过程，但是关于实际结晶器内固态渣 NaOon the crystallization behavior of mold fluxes for casting me- 膜的形成过程和运动情况的研究还不完善.连铸过 dium carbon steel./S///nt,2012,52(12):2220 程中结品器内不同位置处固态渣膜表面微观结构的 [9]Lu B X,Chen K,Wang W L,et al.Effects of Li2O and Na2O on 变化还值得进一步研究. the crystallization behavior of lime-aliminum-based mold flux for (2)关于渣膜导热系数及界面热阻，国内外学 casting high-Al steels.Metall Mater Trans B,2014,45(4):1496 [10]Gao J X,Wen G H,Sun Q H,et al.The influence of Na,O on 者已经做了大量的研究，但不同的测试条件及实验 the solidification and crystallization behavior of CaO-Si02- 方法得到的结果并不完全一致.无论是导热系数还 Al2 0 based mold flux.Metall Mater Trans B,2015,46(4): 是界面热阻，测试原理都与傅里叶导热定律有关，但 1850 这两个量的测定都涉及到高温介质，因此在实验以 [11]Wen G H,Tang P,Yang B,et al.Simulation and characteriza- 及计算中须要设法排除辐射传热的影响. tion on heat transfer through mould slag film.IS//Int,2012,52 (3)现有关于渣膜辐射传热的计算方法没有考 (7):1179 [12]Wen G H,Zhu X B,Tang P,et al.Influence of raw material 虑三层介质内部的多重反射，并且忽略了渣膜传热 type on heat transfer and structure of mould slag.IS//Int,2011, 是传导与辐射的耦合这一条件.如果要准确计算通 51(7):1028 过渣膜的辐射热流，须要建立传导与辐射的耦合传 [13]Yang C L,Wen G H,Sun Q H,et al.Evolution of temperature 热模型，以便描述渣膜形成过程中导热热流及辐射 and solid slag film during solidification of mold fluxes.Metall 热流随时间的变化规律 Mater Trans B,2017,48(2):1292 [14]Mills K C.A short history of mould powders.fronmak Steelmak, (4)目前关于渣膜光学性质的测试都是在常温 2017,44(5):326 下进行的.高温下液渣光学性质的研究，尤其是液 [15]Cho J,Shibata H,Emi T,et al.Thermal resistance at the inter- 渣中微小粒子及气泡对光学性质的影响还不完善， face between mold flux film and mold for continuous casting of 结晶器弯月面处渣膜的传热机理还不清楚.这方面 steels.IS/J Int,1998,38(5):440 内容一方面可以通过对设备的改进实现高温光学性 [16]Park J Y,Sohn II.Evaluating the heat transfer phenomenon and 质的测试，另一方面可以借助相关的光学理论进行 the interfacial thermal resistance of mold flux using a copper disc mold simulator.Int J Heat Mass Transfer,2017,109:1014 定量描述 [17]Tsutsumi K,Nagasaka T.Hino M.Surface roughness of solidi- 参考文献 fied mold flux in continuous casting process.IS//Int,1999.39 (11):1150 [Mills K C,Fox A B,Li Z,et al.Performance and properties of [18]Shibata H.Kondo K,Suzuki M,et al.Thermal resistance be- mould fluxes.fronmak Steelmak,2005,32(1):26 tween solidifying steel shell and continuous casting mold with in- [2]Mills K C.Fox A B.The role of mould fluxes in continuous cast- tervening flux film.ISI/Int,1996,36(Suppl):$179 ing-So simple yet so complex.IS/J Int,2003,43(10):1479 [19]Long X,He P,Wang Q,et al.Structure of solidified films of [3]Mills K C,Courtney L,Fox A B,et al.The use of thermal analy- mold flux for peritectic steel.Metall Mater Trans B,2017,48 sis in the determination of the crystalline fraction of slag films. (3):1652 Thermochim Acta,2002,391(1-2)175 [20]Mill K C.Structure and properties of slags used in the continuous工程科学学报,第 41 卷,第 1 期 长大于 1200 nm 的红外光的反射率随着晶体粒度的 增加而增加,而透过率随晶体粒度的增加而减小,但 是对于含有铁氧化物的保护渣,晶体粒度对光学性 质的影响不大. 除了晶体外,固态渣膜中的气孔同 样对光学性质有影响,Rousseau 等发现多孔材料的 光学性质不仅与孔隙度有关[37] ,还与气孔尺寸有 关. 在孔隙度一定的情况下,气孔的索特平均直径 越小,多孔介质对中红外光(波长在 3 ~ 50 滋m 范围 内)的反射率越大,这意味着固态渣膜中尺寸分布 均匀的小孔可能会对控制辐射传热起到一定的 作用. 3 渣膜形成及传热研究的展望 (1)利用双丝法和水冷铜探头法已经可以模拟 出渣膜的形成过程,但是关于实际结晶器内固态渣 膜的形成过程和运动情况的研究还不完善. 连铸过 程中结晶器内不同位置处固态渣膜表面微观结构的 变化还值得进一步研究. (2)关于渣膜导热系数及界面热阻,国内外学 者已经做了大量的研究,但不同的测试条件及实验 方法得到的结果并不完全一致. 无论是导热系数还 是界面热阻,测试原理都与傅里叶导热定律有关,但 这两个量的测定都涉及到高温介质,因此在实验以 及计算中须要设法排除辐射传热的影响. (3)现有关于渣膜辐射传热的计算方法没有考 虑三层介质内部的多重反射,并且忽略了渣膜传热 是传导与辐射的耦合这一条件. 如果要准确计算通 过渣膜的辐射热流,须要建立传导与辐射的耦合传 热模型,以便描述渣膜形成过程中导热热流及辐射 热流随时间的变化规律. (4)目前关于渣膜光学性质的测试都是在常温 下进行的. 高温下液渣光学性质的研究,尤其是液 渣中微小粒子及气泡对光学性质的影响还不完善, 结晶器弯月面处渣膜的传热机理还不清楚. 这方面 内容一方面可以通过对设备的改进实现高温光学性 质的测试,另一方面可以借助相关的光学理论进行 定量描述. 参 考 文 献 [1] Mills K C, Fox A B, Li Z, et al. Performance and properties of mould fluxes. Ironmak Steelmak, 2005, 32(1): 26 [2] Mills K C, Fox A B. The role of mould fluxes in continuous cast鄄 ing鄄鄄 So simple yet so complex. ISIJ Int, 2003, 43(10): 1479 [3] Mills K C, Courtney L, Fox A B, et al. The use of thermal analy鄄 sis in the determination of the crystalline fraction of slag films. Thermochim Acta, 2002, 391(1鄄2): 175 [4] Zhang P, Wei Q C, Wang J Y, et al. Present state of research on heat transfer of casting flux film in continuous casting mold. J Iron Steel Res, 1995, 7(4): 74 (张平,魏庆成,王家荫,等. 连铸结晶器中保护渣渣膜传热的 研究现状. 钢铁研究学报, 1995, 7(4): 74) [5] Meng Y, Thomas B G. Simulation of microstructure and behavior of interfacial mold slag layers in continuous casting of steel. ISIJ Int, 2006, 46(5): 660 [6] Kashiwaya Y, Cicutti C E, Cramb A W, et al. Development of double and single hot thermocouple technique for in situ observa鄄 tion and measurement of mold slag crystallization. ISIJ Int, 1998, 38(4): 348 [7] Zhou L J, Wang W L, Liu R, et al. Computational modeling of temperature, flow, and crystallization of mold slag during double hot thermocouple technique experiments. Metall Mater Trans B, 2013, 44(5): 1264 [8] Li J, Wang W L, Wei J, et al. A kinetic study of the effect of Na2O on the crystallization behavior of mold fluxes for casting me鄄 dium carbon steel. ISIJ Int, 2012, 52(12): 2220 [9] Lu B X, Chen K, Wang W L, et al. Effects of Li2O and Na2O on the crystallization behavior of lime鄄aliminum鄄based mold flux for casting high鄄Al steels. Metall Mater Trans B, 2014, 45(4): 1496 [10] Gao J X, Wen G H, Sun Q H, et al. The influence of Na2O on the solidification and crystallization behavior of CaO鄄鄄 SiO2 鄄鄄 Al2O3 based mold flux. Metall Mater Trans B, 2015, 46 (4): 1850 [11] Wen G H, Tang P, Yang B, et al. Simulation and characteriza鄄 tion on heat transfer through mould slag film. ISIJ Int, 2012, 52 (7): 1179 [12] Wen G H, Zhu X B, Tang P, et al. Influence of raw material type on heat transfer and structure of mould slag. ISIJ Int, 2011, 51(7): 1028 [13] Yang C L, Wen G H, Sun Q H, et al. Evolution of temperature and solid slag film during solidification of mold fluxes. Metall Mater Trans B, 2017, 48(2): 1292 [14] Mills K C. A short history of mould powders. Ironmak Steelmak, 2017, 44(5): 326 [15] Cho J, Shibata H, Emi T, et al. Thermal resistance at the inter鄄 face between mold flux film and mold for continuous casting of steels. ISIJ Int, 1998, 38(5): 440 [16] Park J Y, Sohn II. Evaluating the heat transfer phenomenon and the interfacial thermal resistance of mold flux using a copper disc mold simulator. Int J Heat Mass Transfer, 2017, 109: 1014 [17] Tsutsumi K, Nagasaka T, Hino M. Surface roughness of solidi鄄 fied mold flux in continuous casting process. ISIJ Int, 1999, 39 (11): 1150 [18] Shibata H, Kondo K, Suzuki M, et al. Thermal resistance be鄄 tween solidifying steel shell and continuous casting mold with in鄄 tervening flux film. ISIJ Int, 1996, 36(Suppl): S179 [19] Long X, He S P, Wang Q, et al. Structure of solidified films of mold flux for peritectic steel. Metall Mater Trans B, 2017, 48 (3): 1652 [20] Mill K C. Structure and properties of slags used in the continuous ·20·