稳态导热下连铸保护渣固态渣膜有效导热系数的研究
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摘要
现有关于连铸保护渣导热系数的测量方法主要有瞬时热线法和激光脉冲法两种,而实际连铸生产过程中既有传导传热也有辐射传热,导热系数无法评价坯壳向结晶器的综合传热,需要用有效导热系数来计算通过渣膜的综合传热。通过热流模拟仪及激光共聚焦显微镜对固态渣膜的有效导热系数进行了研究。结果表明:随着碱度从1.1增加到1.4,连铸保护渣的结晶性能增强,固态渣膜表面粗糙度逐渐增大,拟合得到的有效导热系数从1.20 W/(m·K)增大到2.46W/(m·K)。
It has been reported that two methods could be used to measure the thermal conductivity of mold flux,including the instantaneous hot-wire method and the laser pulse method.However,during continuous casting process,the heat transfer between the shell and the mold involves conduction and radiation.Therefore,the thermal conductivity could not be used to evaluate the total heat flux in the mold.Thus,it is necessary to use the effective thermal conductivity to calculate the total heat flux through the slag film.In this paper,the effective thermal conductivity of the solid slag film was investigated through heat flux simulator and laser confocal microscope.The results show that,with the increase of the basicity from 1.1 to1.4,the crystallization capability of mold flux increases,which leads to the increase of the surface roughness of the solid slag film.Meanwhile,the effective thermal conductivity of the flux increases from 1.20 W/(m·K)to 2.46 W/(m·K).
It has been reported that two methods could be used to measure the thermal conductivity of mold flux,including the instantaneous hot-wire method and the laser pulse method.However,during continuous casting process,the heat transfer between the shell and the mold involves conduction and radiation.Therefore,the thermal conductivity could not be used to evaluate the total heat flux in the mold.Thus,it is necessary to use the effective thermal conductivity to calculate the total heat flux through the slag film.In this paper,the effective thermal conductivity of the solid slag film was investigated through heat flux simulator and laser confocal microscope.The results show that,with the increase of the basicity from 1.1 to1.4,the crystallization capability of mold flux increases,which leads to the increase of the surface roughness of the solid slag film.Meanwhile,the effective thermal conductivity of the flux increases from 1.20 W/(m·K)to 2.46 W/(m·K).
引文
[1]郑伟栋,盖领军,张春杰,等.保护渣对结晶器热流的影响[J].连铸,2007,4(2):40.
[2]倪有金,庞炜光,孙彦辉,等.包晶钢板坯表面纵裂纹的形成与防止[J].连铸,2010,24(4):1.
[3]于雄,文光华,唐萍,等.连铸结晶器保护渣渣膜结晶特性的研究进展[J].材料导报,2010,24(5):101.
[4]Andersson S P,Eggertson C.Thermal conductivity of powders used in continuous casting of steel[J].Ironmaking&Steelmaking,2015,42(6):465.
[5]Waseda Y,Masuda M,Watanabe K et al.Thermal diffusivities of continuous casting powders for steel at high temperature[J].High Temp Mat Pr-Isr,1994,13(4):267.
[6]朱立光,金山同.连铸结晶器内保护渣渣膜状态的数学模拟[J].北京科技大学学报,1999,21(1):13.
[7]Karina Assis.Heat transfer through mould fluxes:a new approach to measure thermal properties of slags[D].Pennsylvania:Carnegie Mellon University,2016.
[8]杨波,唐萍,文光华,等.结晶器保护渣渣膜结构的模拟研究[J].过程工程学报,2011,11(2):349.
[9]孙大乐,吴琼,刘常升,等.激光共聚焦显微镜在磨损表面粗糙度表征中的应用[J].中国激光,2008,35(9):1409.
[10]Shibata H,Kondo K,Suzuki M,et al.Thermal resistance between solidifying steel shell and continuous casting mold with intervening flux film[J].ISIJ international,1996,36(Sl):179.
[11]于雄,文光华,唐萍,等.连铸结晶器保护渣渣膜结晶特性的研究进展[J].材料导报,2010,24(5):101.
[12]Nakada H,Susa M,Seko Y,et al.Mechanism of heat transfer reduction by crystallization of mold flux for continuous casting[J].ISIJ international,2008,48(4):446.
[13]Mills K C,Hayashi M,Wang L,et al.Chapter 2.2.The structure and properties of silicate slags[M].Treatise on Process Metallurgy.Elsevier Ltd,2014:149.
[14]Ozawa S,Susa M,Goto T,et al.Lattice and radiation conductivities for mould fluxes from the perspective of degree of crystallinity[J].ISIJ international,2006,46(3):413.
[2]倪有金,庞炜光,孙彦辉,等.包晶钢板坯表面纵裂纹的形成与防止[J].连铸,2010,24(4):1.
[3]于雄,文光华,唐萍,等.连铸结晶器保护渣渣膜结晶特性的研究进展[J].材料导报,2010,24(5):101.
[4]Andersson S P,Eggertson C.Thermal conductivity of powders used in continuous casting of steel[J].Ironmaking&Steelmaking,2015,42(6):465.
[5]Waseda Y,Masuda M,Watanabe K et al.Thermal diffusivities of continuous casting powders for steel at high temperature[J].High Temp Mat Pr-Isr,1994,13(4):267.
[6]朱立光,金山同.连铸结晶器内保护渣渣膜状态的数学模拟[J].北京科技大学学报,1999,21(1):13.
[7]Karina Assis.Heat transfer through mould fluxes:a new approach to measure thermal properties of slags[D].Pennsylvania:Carnegie Mellon University,2016.
[8]杨波,唐萍,文光华,等.结晶器保护渣渣膜结构的模拟研究[J].过程工程学报,2011,11(2):349.
[9]孙大乐,吴琼,刘常升,等.激光共聚焦显微镜在磨损表面粗糙度表征中的应用[J].中国激光,2008,35(9):1409.
[10]Shibata H,Kondo K,Suzuki M,et al.Thermal resistance between solidifying steel shell and continuous casting mold with intervening flux film[J].ISIJ international,1996,36(Sl):179.
[11]于雄,文光华,唐萍,等.连铸结晶器保护渣渣膜结晶特性的研究进展[J].材料导报,2010,24(5):101.
[12]Nakada H,Susa M,Seko Y,et al.Mechanism of heat transfer reduction by crystallization of mold flux for continuous casting[J].ISIJ international,2008,48(4):446.
[13]Mills K C,Hayashi M,Wang L,et al.Chapter 2.2.The structure and properties of silicate slags[M].Treatise on Process Metallurgy.Elsevier Ltd,2014:149.
[14]Ozawa S,Susa M,Goto T,et al.Lattice and radiation conductivities for mould fluxes from the perspective of degree of crystallinity[J].ISIJ international,2006,46(3):413.