【作者】 毛雪松；

【导师】 顾华志；

【作者基本信息】 武汉科技大学 ， 材料学， 2007， 硕士

【摘要】 本论文从MgO-Al₂O₃-SiO₂系相图出发,研究了添加熔融石英、ρ-Al₂O₃对镁质中间包挡渣墙性能影响研究。第一部分研究以硅微粉为结合剂通过添加具有低热膨胀系数的不同粒度熔融石英来提高镁质浇注料的抗热震稳定性。添加熔融石英后提高了镁质浇注料的热震稳定性,添加熔融石英颗粒效果更好。随着熔融石英加入量的增加对c/s比高的渣抗渣渗透能力逐渐增强,抗渣侵蚀能力逐渐减弱,添加熔融石英颗粒的效果好于添加熔融石英细粉。第二部分在第一部分的基础上,利用ρ-Al₂O₃作结合剂取代部分硅微粉来降低基质部分中硅含量,添加一定量的熔融石英颗粒后,对c/s比高的中间包钢渣抗侵蚀和渗透深度分别降低了2.84mm和3.44mm;而对c/s比低的中间包钢渣抗侵蚀和渗透效果不理想。第三部分为了进一步提高抗渣性能,用棕刚玉细粉取代镁砂细粉并引入少量MA细粉促进MA的生成后,对c/s比低的中间包钢渣具有良好的抗渣侵蚀和渗透性能,而对c/s比高的中间包钢渣抗渣侵蚀和渗透性能稍差。第四部分对抗渣机理进行了SEM研究:通过M2S和MA的生成而产生体积膨胀,一方面可以封闭气孔,另一方面可以形成一定数量、大小适当的微裂纹能阻止裂纹扩展,提高其热震稳定性。MA可以吸收渣中的FeO、MnO形成无限固溶体提高了熔渣的粘度,同时Al₂O₃可以吸收渣中的CaO进一步提高渣的粘度,能更好的抑制中间包钢渣对试样的侵蚀和渗透。更多还原

【Abstract】 The effect of addition of fused silica, andρ-Al₂O₃ on magnesia tundish weir was investigated through the MgO-Al₂O₃-SiO₂ phase diagram in this paper. In the first part, fused silica of different grain size with low thermal expansion coefficient was added into the magnesia material to improve its thermal shock resistance using the micro powder silica as the binder. The thermal shock resistance of magnesia castables is able to be improved by adding fused silica, the effect of adding fused silica particle is significantly better than that of fused silica powder. With the increase of the melting quartz content, the slag corrosion resistance to high CaO/SiO₂ ratio capacity gradually increases. And capacity of slag penetration resistance gradually diminishes, the effect of addition fused silica particles are better than that of adding fused silica powder. On the base of the former research, the second part in this paper usesρ-Al₂O₃ as a binder to replace part of micro silica in order to reduce the silicon content of host material. Addition of suitable fused silica particles help to improve the capability of penetration resistance and corrosion resistance of higher CaO/SiO₂ ratio, the erosion and penetration depth decreased by 2.84mm and 3.44mm after experimentation; but the effect of capability of penetration resistance and corrosion resistance of lower CaO/SiO₂ ratio is not obvious. In the third part, in order to improve corrosion resistance, the author uses brown corundum powder replacing magnesia powder and adds some magnesia-alumina fined powder to generate MA. It is more effective on the lower CaO/SiO₂ ratio tundish slag than that of the higher CaO/SiO₂ ratio tundish slag about performance of penetration resistance and corrosion resistance. In the fourth part, the slag penetration resistance is analyzed by SEM, its conclusion is: the volume increased following the produce of M2S and MA, on the one hand it may seal up the blowhole, on the other hand it may form the micro crack with properly quantity and size. The micro crack can prevent the crack expanding and enhance its thermal shock resistance stability. The magnalium spinel may massively absorb FeO, MnO in the dregs to form the unlimited solution to enhance the slag viscosity, Al₂O₃ can absorb CaO in the dregs to further enhance the viscosity of the dregs, it is better to suppress tundish steel corrosion and permeating to the samples.更多还原