【作者】 郭丽娟；

【导师】 吴芸芸；

【作者基本信息】 武汉科技大学 ， 材料学， 2004， 硕士

【摘要】 本文对提高连铸用塞棒性能的因素进行了研究。全文分为铝碳质和镁碳质两个系列。分别研究了结合剂用量，颗粒粒度分布、添加剂对材料性能的影响规律。重点研究了抗氧化添加剂的种类和加入量对材料性能的影响。 在结合剂用量方面，本文在前人研究的基础上，结合塞棒体系自身的特性，选取一定范围的结合剂加入量进行单因素试验。通过对试样物理性能的检测和对树脂碳化机理的研究，可以得到下面结论：对于临界粒度为1mm的Al₂O₃-C体系，在外加6％左右的酚醛树脂时，可以使物料颗粒得到充分的润湿并且与细粉充分的结合，可以使制品的各项性能达到最佳；对于临界粒度为2mm的MgO-C体系加入4％左右的酚醛树脂较为合适。 在颗粒粒度分布研究方面，根据Andreassen颗粒密堆理论公式，选取一定的q值范围进行单因素试验。对于临界粒度为1mm的铝碳质体系，无论是从物理性能检测方面看还是从电子显微图片方面分析都可以得到以下结论：当粒度分布系数在0.44左右，可达到较合理的粒度分布，并获得较好的性能。对于临界粒度为2mm的镁碳质体系，q=0.40时，试样则结合较为紧密。同时发现，在铝碳体系中，通过降低临界粒度和调整颗粒粒度组成不但不能提高强度，相反试样强度有所降低。 在添加剂研究方面，对锆刚玉和SiC的加入量进行了研究，结论如下：在铝碳体系中加入锆刚玉可以提高试样的强度。加入量在10％时，试样结合致密，强度最高。加入量超过10％时，由于改变了体系的颗粒级配，造成原结构骨架不完整，不连续，而新的结构骨架还未形成，试样气孔增多，强度降低。当SiC加入量小于9％时，在基质中的交错穿插未能连成一体，破坏了原有的整体，致使气孔率增加，强度降低。加入量在6％时，破坏作用最大。 最后对单种添加剂和复合添加剂的使用效果进行了研究。试验证明添加B₄C对提高试样的常温和高温强度、抗氧化性能有利，但降低材料的耐蚀性能，故加入量要适当。具体试验结果如下：对于铝碳体系，添加2％Si+2％B₄C的试样常温和高温强度较高，抗氧化性能较好。而单独加4％Si的试样具有良好的抗渣性和抗钢水侵蚀性能。对于镁碳体系，添加3％Al+1％Si+1％B₄C时，试样常温和高温强度较高，抗氧化性能较好。而同时加入金属Al和BN的试样具有较好的抗钢水侵蚀性能。同时加入金属Al和金属Si的试样具有较好的抗渣侵蚀性能。更多还原

【Abstract】 Some factors affecting properties of stopper for con-casting system are studied in this paper. This paper is divided into two series:Al2O3-C system and MgO-C system. The relationship between amounts of binders, grain granularity distribution, additives and properties of samples are studied respectively. Effect of amounts of different anti-oxidants on properties of samples are studied emphatically.In the view of amounts of binders, amounts of binders are studied, on the basis of work done and combing with the self characteristics of stopper. Through detecting physical properties of samples and studying the carbonization mechanism of resin, the following conclusions can be drawn. For the Al2O3-C system what critical granularity is 1mm, when the amounts of resin are 6%, grain can be surrounded sufficiently by resin and can combine together more compactly with fine powder and the sample has optimal properties. For the MgO-C system what critical granularity is 2mm, the fittest amounts of resin is 4%.In the regard of the experiment of grain granularity distribution, on the basis of the Andreassen formula, through changing the distribution condition of the particle size, it is concluded that grain and matrix combine together more compactly and the sample has higher cold crushing strength, when distribution coefficient equal 0.44 and 0.40 respectively in the Al2O3-C system and in the MgO-C system. Meanwhile, It shows that higher intensity can not be gotten through diminishing critical granularity or adjusting granularity distribution.As for the study on additives, the amounts of zirconia-corundum and SiC added are studied. It indicates that zirconia-corundum added can enhance the intensity of samples in the A12O3-C system. The grain granularity distribution of system is changed when the amounts added is above 10%, this results in the imperfect and noncontinuous structure, meanwhile, new structure has not formed, the porosity of sample increases, intensity decreases. When the amounts of SiC added is below 9%, the original structure is destroyed, result in porosity increases, intensity decreases. Attacking is the most when the amounts of SiC added are 6%.The effects of single additive and multiple additives are studied at the end. Experimental results show that additive of B4C is beneficial for improvement of sample’s intensity at room and elevated temperature , oxidation prevention, but the erosion prevention is decreased, so the amount added should be appropriate. Specific experimental results are as follow: for A12O3-C system, samples added 2%Si+2%B4C have higer intensity at room and elevated temperature, better oxidation resistance. Samples added 4%Si have well corrosion resistance by slag and molten steel. For MgO-C system, samples added 3%Al+l%Si+l%B4C have higher intensity at room and elevated temperature, oxidation resistance. The samples added Al and BN at the same time have well corrosion resistance by molten steel. The samples added Al and Si at the same time have well corrosion resistance by slag.更多还原