熔铸AZS耐火材料冷却过程的热应力研究

摘要

熔铸AZS材料是一类非常重要的耐火材料,在其制备过程中常常因为热应力过大而损坏.运用有限元法模拟AZS铸件冷却过程中的热应力场,分别研究了加设保温层、铸模材料的热导率以及热对流系数对热应力的影响.计算结果表明:在铸模与砂箱之间加设保温层能够有效降低铸件本身的热应力;改变铸模材质的热导率不仅影响热应力的峰值,而且影响峰值出现的早晚以及高应力水平维持的时间长短;热对流系数对应力峰值以及峰值出现时间早晚的影响都不明显,只影响高应力水平维持的时间长短.%Al2O3-ZrO2-SiO2 material (known as AZS) is an important kind of refractories.High stress always damages AZS during preparation.The thermal stress field of the AZS cast during cooling was simulated by finite element method.The influences of setting an insulating layer,the thermal conductivity of the mold material,and the heat convection coefficient on thermal stress were studied.Calculation results indicate that setting an insulating layer between the casting mold and the sand box can lower the thermal stress of the cast;the thermal conductivity of the mold material not only affects the peak value of the thermal stress but also influences the time that peak appears and the high stress lasting time;the heat convection coefficient has no obvious influence on the stress peak value and the time the peak appears, but influences the high stress lasting time.