Solidification structure is critical in the control of the mechanical properties and quality during the continuous casting process. The thermo-physical properties of 13 Cr steel added some rare metals, such as Mo, V, ...Solidification structure is critical in the control of the mechanical properties and quality during the continuous casting process. The thermo-physical properties of 13 Cr steel added some rare metals, such as Mo, V, Nb, are measured to better understand the solidification structure of 13 Cr bloom. A computational model using CA-FE(cellular automation-finite element) method coupled with heat transfer model is developed to describe the solidification structure in continuous casting process. It is found that the calculated solidification structure is in good agreement with the observed data. The influence of casting speed and superheat on the solidification structure of the bloom is studied in detail. In order to obtain more equiaxed crystal ratio and low degree of the segregation in the bloom, the optimized casting speed 0.6 m/min and superheat less than 25 °C are determined for the caster. Using the optimized manufacturing parameters, these samples are 60% with the equiaxed zone ratio of 8%–10% and below the degree of segregation 1.05.展开更多
This paper aims to investigate thermal radiative characteristics of thermochrornic material La0.825Sr0.175MnO3（LSMO） with one-dimensional grating structured surfaces. The dielectric function of LSMO was calculated b...This paper aims to investigate thermal radiative characteristics of thermochrornic material La0.825Sr0.175MnO3（LSMO） with one-dimensional grating structured surfaces. The dielectric function of LSMO was calculated by K-K approach. Numerical calculation was conducted to obtain spectral emittance distribution of such surfaces with different structural parameters using the finite difference time domain （FDTD） method. It was found that the spectral emittance of LSMO structured surface exhib- ited the feature of selective enhancement due to the excitation of microcavity effect. The effects of structural parameters on spectral emittance indicated that the desired radiative enhancement could be achieved by the rational design of the structural parameters of grating. The temperature dependence of averaged emittance of LSMO was also calculated, The results showed that LSMO with grating structured surface had a better thermochromic performance compared with LSMO with smooth surface.展开更多
基金Projects(51274057,51474057) supported by the National Natural Science Foundation of ChinaProject(2012AA03A508) supported by the High-tech Research and Development Program of China
文摘Solidification structure is critical in the control of the mechanical properties and quality during the continuous casting process. The thermo-physical properties of 13 Cr steel added some rare metals, such as Mo, V, Nb, are measured to better understand the solidification structure of 13 Cr bloom. A computational model using CA-FE(cellular automation-finite element) method coupled with heat transfer model is developed to describe the solidification structure in continuous casting process. It is found that the calculated solidification structure is in good agreement with the observed data. The influence of casting speed and superheat on the solidification structure of the bloom is studied in detail. In order to obtain more equiaxed crystal ratio and low degree of the segregation in the bloom, the optimized casting speed 0.6 m/min and superheat less than 25 °C are determined for the caster. Using the optimized manufacturing parameters, these samples are 60% with the equiaxed zone ratio of 8%–10% and below the degree of segregation 1.05.
基金supported by the National Natural Science Foundation of China (Grant No.50936002,50876044)
文摘This paper aims to investigate thermal radiative characteristics of thermochrornic material La0.825Sr0.175MnO3（LSMO） with one-dimensional grating structured surfaces. The dielectric function of LSMO was calculated by K-K approach. Numerical calculation was conducted to obtain spectral emittance distribution of such surfaces with different structural parameters using the finite difference time domain （FDTD） method. It was found that the spectral emittance of LSMO structured surface exhib- ited the feature of selective enhancement due to the excitation of microcavity effect. The effects of structural parameters on spectral emittance indicated that the desired radiative enhancement could be achieved by the rational design of the structural parameters of grating. The temperature dependence of averaged emittance of LSMO was also calculated, The results showed that LSMO with grating structured surface had a better thermochromic performance compared with LSMO with smooth surface.
