【摘要】 分析了热风管用莫来石-红柱石砖在服役不同年限后的性能与显微结构,对结构和组成的变化进行了研究和对比。结果表明:H21砖服役27年后,其基质中二次莫来石生长发育好,致密,结合相中Al₂O₃含量高,对抗热震性能有利,但不同方向生长的莫来石形成的孔洞会增加气孔率。合适的基质组成,利于二次莫来石的适度生长。而基质中SiO₂含量高对二次莫来石的生长不利。在长期服役的热风管内衬的选择上,需要考虑组成与结构的匹配问题,以应对高温长久服役条件下的显微结构变化,在风温普遍提高的形势下,需要根据风温的高低,适当提高热风管砖的档次,以提高其使用寿命。利用长时间服役后材料的结构与组成分析反向推断材料的合适匹配,是耐火材料研究的一个方向。更多还原

【Abstract】 The properties and microstructure of mullite-andalusite bricks used in hot blast pipes for different years were analyzed. The changes in structure and composition were studied and compared. The results show that in the brick H21 used in hot blast pipes for 27 years,the secondary mullite grows well and densely in the matrix,and the bonding phase has high Al₂O₃ content,which is conductive to the thermal shock resistance of the brick,but the holes created by the different growth directions of mullite increase the porosity; suitable matrix composition benefits the growth of mullite,but the high content of SiO₂ is harmful to it.Thus,as for the selection of lining materials for hot blast pipes,the matching of structure and composition should be considered to cope with the microstructure evolution during long-time high temperature service.Considering that the hot blast temperature keeps increasing,it is necessary to enhance the grade of the refractory materials based on the hot blast temperature in order to prolong the service life. It is also a direction for refractory researchers to study the microstructure and the composition of the used refractories to reversely deduce the matching of the refractories.更多还原