焦宝石基结构梯度耐火材料的设计及热应力分析  

Design and thermal stress analysis of structural gradient flint clay based refractories

作　　者：刘巍 曹喜营[1] 冯海霞[1] 陈建军 Liu Wei;Cao Xiying;Feng Haixia;Chen Jianjun

机构地区：[1]中钢集团洛阳耐火材料研究院有限公司先进耐火材料国家重点实验室,河南洛阳471039

出　　处：《耐火材料》2018年第5期347-353,共7页Refractories

摘　　要：为了改善耐火材料的抗热震性能,从梯度耐火材料的性能梯度和结构梯度出发,以焦宝石、α-Al_2O_3微粉和SiO_2微粉为原料,磷酸二氢铝溶液为结合剂,混练后的泥料分别在20、60、100和140 MPa的压力下成型,再于600℃保温3 h热处理制成焦宝石基黏土砖,然后检测不同成型压力试样的热膨胀性、显气孔率、热导率和弹性模量,并利用ANSYS有限元法对不同成型压力试样的性能渐变梯度(自身温度场原位形成)和结构梯度(气孔结构)进行叠加,在热面温度和冷面温度分别为1 300和500℃的边界条件下,对叠加前后的结构进行温度、应力、变形量的模拟分析研究。结果表明:1)试样的热膨胀系数随温度升高而逐渐降低,在设定边界条件下的温度场作用下,可以形成较适宜的性能渐变梯度;不同结构试样的热膨胀曲线有一定差异,可用于结构梯度耐火材料的设计。2)在性能渐变梯度与结构梯度叠加作用下,结构梯度D1(从高温面到低温面成型压力增加)与结构梯度D2(从高温面到低温面成型压力降低)相比,结构梯度D1的最大应力较小,沿Y轴负方向的最大变形量显著降低;与均一结构相比,结构梯度D2的最大应力与最大变形量显著增加,结构梯度D1的最大应力与成型压力为60、100、140 MPa的均一结构相比明显改善。3)成型压力对试样结构的改变有限,需要对其性能梯度和结构梯度进行进一步优化,使试样热膨胀曲线与理想曲线接近或一致。This work aims at improving the thermal shock resistance of refractories from the aspect of gradient refractories with property gradient and structural gradient. Flint clay, α-Al2O3 micropowder,and SiO2 micropowder were used as starting materials,and aluminium dihydrogen phosphate solution as the binder to prepare flint clay based brick. The materials were shaped （20,60,100 and 140 MPa） ,and fired at 600℃ for 3 h to obtain the specimens. The thermal expansibility, apparent porosity,thermal conductivity and elastic modulus of the specimens were measured. The property gradient （ in situ formation by the self temperature field） and structural gradient （pore structure） of the specimens shaped under different pressures were superimposed using ANSYS finite element method. Numerical simulation analysis on the temperature field, stress field and structure deformation before and after the superimposition was carried out with the boundary conditions： the hot surface temperature of 1300 ℃ and the cold surface temperature of 500 ℃. The results show that ：1 ）the thermal expansion coefficient of the specimens decreases gradually with the increase of the temperature;and with the boundary condition of the temperature field,suitable property gradient can be formed. The thermal expansion curves of specimens with different structures are different,which can be used for the design of structural gradient refractories. 2） Under the superimposition of property gradient and structural gradient,structural gradient D1 （molding pressure increasing from high temperature face to low temperature face） has smaller maximum stress than D2（molding pressure decreasing from high temperature face to low temperature face） ;and the maximum deformation along the negative direction of Y axis decreases significantly. Compared with the uniform structure, structural gradient D2 has significantly larger maximum stress and deformation. Compared to the uniform structure with molding pressure of 60 MPa,100 MPa and 140 MPa, D1

关 键 词：梯度耐火材料 抗热震性 结构梯度 成型压力 温度场 有限元分析 

分 类 号：TQ175[化学工程—硅酸盐工业]