热轧薄带钢层流冷却边部遮蔽模拟及分析  

Simulation and analysis of edge shielding in laminar cooling of hot rolled thin gauge strip

作　　者：廖钢 余伟[2] 夏梓崴 LIAO Gang;YU Wei;XIA Ziwei(Valin Lianyuan Iron and Steel Co.,Ltd.,Loudi 417000,China;National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]湖南华菱涟源钢铁有限公司,湖南娄底417000 [2]北京科技大学高效轧制与智能制造国家工程研究中心,北京100083

出　　处：《轧钢》2024年第3期119-126,共8页Steel Rolling

摘　　要：针对卷取温度为660~680℃的Q235B热轧薄带钢在层流冷却过程中由于边部过冷易出现板形缺陷的问题,建立了2 250 mm热轧生产线边部低温区宽度SC预测模型,预测误差控制在±6 mm,建立了热轧薄带钢层流冷却有限元模型,对比模拟了层流冷却和等宽边部遮蔽策略下冷却过程中带钢宽度方向的温度场、相变比例和残余应力分布。结果表明:层流冷却过程中,带钢边部与中部存在300℃温差,低温快冷使得边部出现体积分数约33.48%的贝氏体,并同时产生拉应力与压应力;应用等宽边部遮蔽后,将带钢边部和中部温差控制在±15℃内,消除了边部贝氏体组织,同时将边部和中部的铁素体相变体积分数差值由18.6%降低到5.11%,使得相变比例和残余应力分布更加均匀,改善了冷却板形,消除了带钢边浪缺陷。Aiming at the problem of shape defects due to overcooling at the edges during laminar cooling of Q235B hot rolled thin gauge strip at coiling temperatures between 660-680℃,a predictive model for the width Sc of the low-temperature zone along the edges of a 2250 mm hot rolling production line was developed,with a prediction error controlled within±6 mm.A finite element model of laminar cooling for hot rolled thin gauge strip was established to compare and simulate the temperature field across the width of the strip,the proportion of phase transformation,and the distribution of residual stresses under conditions of laminar cooling and uniform edge shielding strategies.The results indicate that during laminar cooling,a temperature difference of 300 C between the edges and the middle of the strip causes rapid cooling at low temperatures,leading to the formation of bainite structure with a volume fraction of approximately 33.48%at the edges,accompanied by the generation of tensile and compressive stresses.By applying uniform edge shielding,the temperature difference between the edges and the middle of the strip was controlled within±15 ℃,eliminating edge bainite structure while reducing the difference in the volume fraction of ferrite phase transformation between the edge and middle from 18.6%to 5.11%,thereby making the phase transformation proportion and residual stress distribution more uniform,improving the cooling strip shape,and eliminating wave defects at the edges of the strip.

关 键 词：热轧薄带钢 层流冷却 低温区宽度预测模型 边部遮蔽 有限元模拟 

分 类 号：TG335.56[金属学及工艺—金属压力加工]