Abstract: During production of 150 ~ 180 mm casting slab of SS400, D36 and X70 steel with casting speed 0. 95 m/min by 1^# caster at steelworks the longitudinal crack at comer of slab easily occurs and the max occurrence rate of crack is up to 5%. The solidification and heat transfer model of two-dimensional slice type of slab casting mold has been established by using commercial finite element software ANSYS and the calculation of solidification and heat transfer in mold during casting process has been carried out by using heat transfer and stress/strain direct-coupling method to analyze the distribution of temperature in slab with casting rate 0. 95 ~ 1. 05 m/min of each steel and the thermal stress introduced by uneven temperature distribution. Commercial test results show that based on the calculation results, it is available to eliminate the longitudinal crack at comer of slab casting by 1^# caster by improving the slab mold narrow face taper coefficient from original 1.00% to 1. 10%.

Key words: Low Carbon Steels, 150 ~ 180 mm Casting Slab, Longitudinal Crack at Comer, Mold, Finite Element Model, Taper Optimization

摘要： 钢厂1^#连铸机以0.95 m/min拉速生产SS400,D36和X70钢150~180 mm连铸板坯时,易产生角部纵裂纹,发生率最高可达5%。利用商业有限元软件ANSYS,建立了板坯连铸结晶器二维切片式凝固传热数学模型,并采用传热和应力/应变直接耦合的方法对连铸过程结晶器内凝固传热进行计算,分析了各钢种在0.95~1.05m/min拉速下铸坯温度分布以及温度分布不均引起的热应力。工业试验结果表明,根据优化计算结果,将板坯结晶器窄面的锥度系数由原来的1.00%改进为1.10%后,有效地消除了1^#连铸机板坯的角部纵裂纹。

关键词: 低碳钢150 ~ 180 mm连铸板坯, 角部纵裂纹, 结晶器, 有限元模型, 锥度优化