压蠕变实验方法对硅砖蠕变结果的适应性探究  

Evaluation of Creep Results of Silica Brick by Creep Test Method

作　　者：张秀华[1] 李勇[1] 田志宏[2] 郑清瑶 邢东明 和弦 薄钧 ZHANG Xiuhua;LI Yong;Tian Zhihong;ZHENG Qingyao;XING Dongming;HE Xian;BO Jun(School of Material Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China;China Metallurgical Research Institute Co.,Ltd.Beijing 100088,China;Sinosteel refractory Co.,LTD,Luoyang,471039,Henan,China)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]中冶建筑研究总院有限公司,北京100088 [3]中钢耐火材料有限公司,河南洛阳471039

出　　处：《硅酸盐学报》2020年第9期1499-1504,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(51872023)。

摘　　要：以结晶硅石为原料、石灰乳及铁鳞为结合剂,成型后经隧道窑1 450℃烧成制得硅砖。取残余石英含量(按YB/T 172测量)不同的烧后砖7块,按照GB/T 5073-2005进行压蠕变实验。结果表明:样品的蠕变特性按形变率变化可分为3个阶段:分别为室温至900℃左右的明显膨胀,膨胀量与残余石英量呈正相关;900℃至1 450℃的明显收缩,收缩量与残石英量呈负相关;1 450℃恒温期间趋于稳态蠕变状态,残余石英量低的样品蠕变曲线变化较平缓。按照GB/T 5073得到的蠕变曲线与硅砖在整个加热升温过程的膨胀或收缩不一致,因蠕变温度≤1 470℃,方石英最终将向鳞石英转变,低残余石英量的样品可能为负值(收缩),高残余石英量的样品通常为正值(膨胀)。残余石英量对蠕变结果影响大,只是按GB/T 5073-2005压蠕变实验方法评述硅砖蠕变性能对准确评价硅砖的高温性能易产生歧义。Industrial silica bricks were obtained in tunnel kiln by sintering at 1 450 ℃ with crystalline silica as a raw material, and lime milk and iron scale as binders. The creep in compression tests was carried out on 7 fired bricks with different residual quartz contents according to the standard GB/T 5073-2005. The results show that the test can be divided into three stages from room temperature to the end of creep according to the change of deformation rate. The distinct expansion stage occurs from room temperature to 900 ℃, and the expansion is positively correlated to the residual quartz content. The distinct shrinkage stage appears from 900 to 1 450 ℃, and the shrinkage is negatively correlated to the residual quartz content. The creep tends to be steady at 1 450 ℃, and the samples with a low residual quartz content show a better stability. The creep curve of silica brick obtained based on GB/T 5073 is not consistent with the expansion or contraction during the whole heating process. At the creep temperature(i.e., ≤1 470 ℃), cristobalite will translate to tridymite, and the samples with a low residual quartz content tend to be negative(i.e., shrinkage), while those with a high residual quartz content are positive(i.e., expansion). The residual quartz content has an influence on the creep process. It could be questionable to evaluate creep high-temperature performance of silica brick just according to GB/T 5073-2005 creep test method.

关 键 词：硅砖 高温蠕变 残余石英 鳞石英 方石英 

分 类 号：TQ175[化学工程—硅酸盐工业]