【作者】 王玮；

【导师】 汪厚植；

【作者基本信息】 武汉科技大学 ， 材料学， 2009， 硕士

【摘要】 本论文首先采用刚玉、电熔镁砂、α-氧化铝微粉、镁铝尖晶石等为原料,分别以纯铝酸钙水泥、硅微粉、ρ-氧化铝微粉、铝凝胶粉为结合剂制成铝镁浇注料,对比四种结合剂所制得浇注料的物理性能,以及对攀钢转炉钒钛渣和武钢转炉渣与铝镁浇注料抗渣性之间的关系进行研究。结果表明,四种结合系统中,铝凝胶粉结合铝镁浇注料具有优良的体积稳定性、较高的耐压强度和合适的高中低温强度比。不论是攀钢钒钛渣还是武钢渣,凝胶结合和ρ-氧化铝微粉结合浇注料抗渣性能都较好,其次是硅微粉结合的浇注料,水泥结合浇注料抗渣性能最差。试样的显微结构分析显示,铝凝胶粉结合和ρ-Al₂O₃微粉结合浇注料渣蚀后蚀变层中多形成MA、CA2、CA6等高熔点相和C2AS低熔点相,它们互相交错分布。相比之下,武钢渣侵蚀后的铝凝胶粉结合和ρ-Al₂O₃浇注料试样中形成的高熔点相数量多,而且结合相对致密。铝镁浇注料具有优异的抗渣性能和良好的抗热震性,其中镁铝尖晶石组分起着十分重要的作用。镁质结合剂主要由MgO、SiO₂组成,中位粒径小于10μm,。采用镁质结合剂取代上述结合剂,细小的MgO与Al₂O₃高温下原位反应生成的镁铝尖晶石,活性高,分布均匀,因此,铝镁浇注料抗渣性能和抗热震性更加优越。同时,由于镁质结合剂具有双峰结构,所以,可以防止镁铝尖晶石的生成速度过大引起的快速膨胀导致浇注料结构破坏。实验结果表明,镁质结合剂结合铝镁浇注料具有与ρ-Al₂O₃或铝凝胶粉同样的“自结合”的效果,不但强度大,而且抗渣性能好,特别是热震稳定性高。但是,镁质结合剂的加入量过高或过低,铝镁浇注料的性能都会降低。对比了分别以白刚玉、板状刚玉、棕刚玉为骨料、镁质结合剂结合的铝镁浇注料物理性能及其对攀钢钒钛渣的抗渣性,结果显示,三种刚玉骨料的铝镁浇注料,强度较高,抗渣性能良好,白刚玉、板状刚玉骨料的铝镁浇注料高温烧后线变化率为微膨胀,棕刚玉骨料的铝镁浇注料高温烧后收缩较大,白刚玉骨料的铝镁浇注料热震稳定性较板状刚玉、棕刚玉骨料的强。比较了镁质结合剂、铝凝胶粉、镁铝尖晶石微粉及镁质结合剂与凝胶粉复合结合剂制成的铝镁浇注料性能,其中镁铝尖晶石微粉及镁质结合剂与铝凝胶粉复合结合剂制成的铝镁浇注料性能不具优势,镁质结合剂的铝镁浇注料尽管常温抗折强度和耐压强度不及铝凝胶粉结合剂的铝镁浇注料,但是,中温、高温烧后强度大,抗热震性和抗渣性优于铝凝胶粉结合剂的铝镁浇注料。更多还原

【Abstract】 In this artical, corundum, fused magnesia,α-alumina powder and Magnesia-Alumina spinel were used as raw material. And pure calcium alumina cement, silica powder,ρ-alumina powder and Alumina-gel powder were used as different bonder agents. On the basis, the physical properties of castable using different conjugation agent were compared, and the relationships between bonder agent and slag resistance of alumina-magnesia castable, the slags refer converter vanadium-titanium slag and converter slag.The results show that alumina-magnesia castable bonded by Alumina-gel powder have excellent volume stability, higher cold compressive strength and suitable strength ratio in high, medium and low temperature. And either the vanadium-titanium slag from PANZHIHUA IRON & STEEL （GROUP） CO. or the slag from WUHAN IRON & STEEL （GROUP） CO., the slag resistance of alumina-magnesia castable that combined with gel orρ-alumina powder is better, the second is bonded with silica powder, the worst is the castable combined with cement. The analysis of sample microstructure exhibit that high and low melting point phase were formed which staggered distribution of each other in the slag corrosion layer of the castable bonded by Alumina-gel powder orρ-alumina powder, such as MA, CA2, CA6 and C2AS etc. In contrast, the number of high melting point phase is more in the castable samples combined with Alumina-gel powder orρ-alumina powder eroded by the slag from WUHAN IRON & STEEL （GROUP） CO., and has a relatively dense combination.Alumina-magnesia castable has excellent slag resistance and good thermal shock resistance, and mgnesia-alumina spinel plays a very important role as one of the components. Magnesia binder was the median particle size under 10μm and mainly composed of MgO and SiO₂. In the paper, magnesia binder was used instead of above mentioned to get more excellent slag resistance and thermal shock resistance for mgnesia-alumina spinel got in situ reaction by MgO and Al₂O₃ in high temperature. At the same time, for the bimodal particle size distribution of the magnesia binder, the rapid expansion of castable lead to structural damage caused by generate excessive speed was prevented. The results show that the magnesia combined castable have the same combined effect as bonded by Alumina-gel powder orρ-alumina powder, not only has great strength, but also has good slag resistance, and special the high thermal shock resistance. But the addition of magnesia binder is too much or too little, the performance of aluminum-magnesium casting material will be reduced.Compared the physical properties and the slag resistance to slag from PANZHIHUA IRON & STEEL （GROUP） CO. of the Alumina-magnesia castable combined by magnesia, and in the castable, white corundum, tabular alumina, or corundum were used for the aggregate respectively. The results show that the three different castable all have high strength, and good slag resistance. The line rate of change after high temperature of the castable made by white corundum or tabular aluminafiring has micro swell, while the castable made by corundum has greater contraction. Thermal shock resistance of alumina-magnesia castable made by white corundum is the best.The performances of castable combined by magnesite-alumina spinel powder or magnesia and Alumina-gel powder composite binder did not have advantages compared the other binders. Although the breaking strength and compressive strength at room temperature of the alumina-magnesia castable combined by magnesia is lower than the castable combined by Alumina-gel powder, the strength after sintering in medium and high temperature is greater, slag resistance and thermal shock resistance was better than that.更多还原