960高强钢板坯凝固过程模拟与工艺优化

Solidification Process Simulation and Process Optimizationof 960 High Strength Steel Slabs

基于凝固传热模型,对断面尺寸为230 mm×1330 mm的960高强钢板坯的温度场进行了数值模拟,并通过射钉试验和表面温度测量试验对凝固传热模型进行验证和优化,分析了比水量、过热度和拉速对板坯温度场和凝固末端位置的影响。二冷区比水量每增加0.05 L/kg,铸坯的凝固终点位置前移0.376 m左右;过热度每增加10 K,铸坯的凝固终点位置后移0.82 m左右;拉速每增加0.1 m/min,凝固终点位置向后移动2.15 m左右。最后,对压下位置和压下量进行了调整,由3个扇形段压下改为2个扇形段压下,压下位置由第9#、第10#、第11#段改为第11#、第12#段,第11、第12#段压下量分别改为2.5、2.0 mm。工艺优化后,铸坯的中心偏析和中心疏松得到明显改善,二者评级结果均由优化前2.0降低为1.5。

Numerical simulations of the temperature field of an slab of 960 high strength steel with a cross-section size of 230 mm×1330 mm have been carried out based on a solidification heat transfer model.The solidification heat transfer model was validated and optimized by nail shooting and surface temperature measurement experiments,and the effects of specific water flow,superheat and casting speed on the temperature field and solidification end of slabs were analyzed.When the specific water flow in the second cooling zone increases by 0.05 L/kg,the solidification end position of the billet moves forward by about 0.376 m;when the superheat increases by 10 K,the solidification end position of the billet moves backward by about 0.82 m;when the pulling speed increases by 0.1 m/min,the solidification end position moves backward by about 2.15 m.The solidification end position of the billet moves backward by about 2.15 m.The solidification end position of the billet moves backward by about 2.15 m.Finally,the reduction position and amount were adjusted,from 3 segments to 2 segments,the reduction position was changed from 9th,10th,11th segment to 11th,12th segment,and the reduction amounts of 11th,12th segment were changed to 2.5,2.0 mm,respectively.After the process optimization,the center segregation and center porosity of the billet are obviously improved,and the rating results of the two are reduced from 2.0 to 1.5 before optimization.