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连铸结晶器中形成的保护渣膜在润滑与传热方面起重要作用,但渣膜的厚度和结构还没有完全被人们所了解。本次研究中,保护渣膜试样是取自浇铸结束后连铸结晶器内,保留浇铸期间所处位置的渣膜。通过此次试验,清楚了结晶器内弯月面处保护渣膜的厚度。根据显微镜下对渣膜截面的观察,研究了渣膜的结构,即渣膜的结晶情况。此外,基于上述观察结果,研究了结晶器内通过渣膜的传热现象,得出以下结论:(1)确认结晶器内保护渣膜的厚度约为1mm。玻璃层为连铸中钢水顶部的熔融保护渣,浇铸结束后成为薄膜,将其假定为浇铸期间的保护渣膜。(2)按结晶器保护渣消耗量可估算出浇铸期间渣膜中的液渣层厚度。(3)弯月面处渣膜约1mm厚时,辐射及传导的总热阻与渣膜和结晶器之间的界面热阻相等。(4)文中提到的界面热阻可能大于实际浇铸中结晶器的热阻。原因可能是由于这些热阻是在无钢水压力情况下测得的,实际结晶器内的界面热阻似乎较小。
The flux film formed in the continuous casting mold plays an important role in lubrication and heat transfer, but the thickness and structure of the slag film have not yet been fully understood. In this study, the protective slag sample was taken from the continuous casting mold after the casting was completed, and the slag film remained during casting. Through this test, clear the mold at the meniscus mold flux film thickness. According to the observation of the cross section of the slag film under the microscope, the structure of the slag film, ie, the crystallization of the slag film, was studied. In addition, based on the above observations, the phenomenon of heat transfer through the slag film in the mold was studied. The following conclusions were drawn: (1) The thickness of the mold powder in the mold was confirmed to be about 1 mm. The glass layer is the molten mold flux on the top of the molten steel in the continuous casting and becomes a film upon completion of the casting, which is assumed to be the protective film during casting. (2) according to the consumption of mold flux can be estimated during casting slag layer in the slag layer thickness. (3) When the meniscus slag film is about 1mm thick, the total thermal resistance of radiation and conduction is equal to the thermal resistance of the interface between the film and the mold. (4) The thermal interface resistance mentioned in the text may be greater than the thermal resistance of the mold in actual casting. The reason may be that these thermal resistances are measured in the absence of molten steel pressure and the thermal interface resistance in the actual mold seems to be small.