在内衬材料中添加氢氧化铝提升长水口的抗热震性:内衬材料显微组织与性能及长水口颈部最大热应力数学模型  

Improving Thermal Shock Resistance of Long Nozzle by Adding Aluminum Hydroxide into Lining Material: Microstructure,Properties of Lining Material,and Mathematical Model for Maximum Thermal Stress of Long Nozzle Neck Portion

作　　者：田响宇 尚心莲 李红霞[1] 王新福[1] 刘国齐[1] 杨文刚[1] 于建宾[1] TIAN Xiangyu;SHANG Xinlian;LI Hongxia;WANG Xinfu;LIU Guoqi;YANG Wengang;YU Jianbin(State Key Laboratory of Advanced Refractories,Sinosteel Luoyang Institute of Refractories Research Co.Ltd.,Luoyang 471039;AVIC Manufacturing Technology Institute,Beijing 100024)

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,洛阳471039 [2]中国航空制造技术研究院,北京100024

出　　处：《材料导报》2019年第4期611-616,共6页Materials Reports

基　　金：国家自然科学基金(51772277;51372231);河南省科技创新人才计划项目(164100510023);河南省基础与前沿研究项目(162300410057)~~

摘　　要：本工作旨在通过向内衬材料中加入氢氧化铝来提升长水口部件的抗热震性。以氧化铝空心球、烧结刚玉为主要原料,配以不同含量的α-Al2O3微粉和干基氢氧化铝,经过预混、成型、热处理,制备了一系列长水口内衬材料。利用XRD和SEM进行显微组织分析,发现氢氧化铝含量的变化并未改变内衬材料的相组成,材料中氢氧化铝呈孤岛状分布。对内衬材料开展了若干力学及热学性能测试,结果表明,随氢氧化铝含量的增加,内衬材料体积密度降低,气孔率升高,常温抗折强度、弹性模量、热导率和热膨胀系数均降低。之后通过有限元法与回归分析,进一步建立了内衬材料热膨胀系数α、弹性模量E、热导率λ三种因素与复合长水口颈部最大热应力σmax之间的数学模型,在该模型中,σmax与α、E和λ之间呈交叉线性关系。结合力学、热学性能测试结果,借助所得数学模型,预测氢氧化铝含量与σmax呈负相关关系(即与长水口抗热震性呈正相关关系)。最后,对比了普通硅质长水口内衬与Al2O3-Al(OH)3体系内衬的实际使用效果,前者与后者的侵蚀速率分别为0. 049 mm/min和0. 032mm/min。The purpose of the present work is to promote thermal shock resistance of long nozzles by adding aluminum hydroxide into the lining mate-rial.A series of long nozzle lining materials differing in α-Al2O3 powder content and dried Al(OH)3 content were prepared,by using Al2O3 hollow spheres and sintered corundum as main raw materials,and through the processes of preblending,forming and heat treatment (at 950 ℃).Microstructure analyses based on XRD and SEM confirmed the same phase composition of the lining materials despite the variation of Al-(OH)3 content,as well as a discontinuous distribution of Al(OH)3 within the material.The mechanical and thermal properties tests showed that,the increase of Al(OH)3 could lead to the declines of bulk density (higher pore ratio),room temperature flexural strength,elastic modulus,and thermal conductivity and expansion coefficient,with respect to the lining materials.Furthermore,by applying finite element analysis and linear regression,we established a mathematical model for the maximum thermal stress of the neck portion of long nozzle (σ max ),in which σ max exhibited a ‘cross linear relationship’ with thermal expansion coefficient (α),elastic modulus ( E ) and thermal conductivity (λ) of lining material.Then combined the obtained mechanical & thermal properties and the proposed model,and as a result the inverse correlation between Al(OH)3 content and σ max (i.e.positive correlation between Al(OH)3 content and thermal shock resistance) could be revealed.Finally we fabricated long nozzles with the Al2O3-Al(OH)3 lining and the ordinary silica lining,respectively,and compared their practical operation performances.The erosion rate results of the former and the latter were 0.032 mm/min and 0.049 mm/min,which supported the proposed mathematical model.

关 键 词：连铸 长水口内衬 氢氧化铝 颈部最大热应力 数学模型 侵蚀速率 

分 类 号：TQ175[化学工程—硅酸盐工业]