φ800 mm大断面连铸圆坯凝固传热和凝固组织模拟  

Simulation of heat transfer and microstructure during solidification of ϕ800 mm large section continuous casting round billet

作　　者：任春节 冷永磊 尹修刚 任立坤 邢伟 张英男 刘福斌 姜周华 REN Chunjie;LENG Yonglei;YIN Xiugang;REN Likun;XING Wei;ZHANG Yingnan;LIU Fubin;JIANG Zhouhua(School of Metallurgy,Northeastern University,Shenyang 110000,Liaoning,China;Chengde Jianlong Special Steel Co.,Ltd.,Chengde 067000,Hebei,China)

机构地区：[1]东北大学冶金学院,辽宁沈阳110000 [2]承德建龙特殊钢有限公司,河北承德067000

出　　处：《连铸》2024年第6期21-30,共10页Continuous Casting

基　　金：辽宁省科技计划联合计划资助项目(2023JH2/101700302)。

摘　　要：以钢厂断面尺寸为φ800 mm的圆坯42CrMo4钢为研究对象,结合ProCAST有限元法和CAFE法建立大圆坯模型,对比了过热度、拉速和二冷区比水量对大圆坯凝固行为和晶粒组织的影响。结果表明,拉速变化对铸坯凝固过程中的温度、凝固终点和凝固坯壳厚度的影响更大,而过热度对连铸过程的晶粒生长影响更大。拉速每提高0.02 m/min,凝固终点后移约3 m,过热度和二冷区比水量改变对温度和中心固相率影响不明显。当过热度从10℃增加到55℃时,等轴晶率从43.2%降低到9.2%,而拉速和二冷区比水量对等轴晶率的影响均不明显,变化都在8%以内。基于末端电磁搅拌位置,对现有工艺提出了优化方案,过热度降低至10℃,比水量降低至0.16 L/kg,可以有效提高等轴晶率,同时细化晶粒。Taking 42CrMo4 round billet with a section size ofϕ800 mm as the research object,a large round billet model was established with ProCAST finite element method and CAFE method.The effects of superheat,drawing speed and specific water volume in secondary cooling zone on solidification behavior and grain structure were compared.The results show that the influence of the drawing speed on the solidification temperature,solidification end point and the thickness of the solidified billet is greater,while the influence of superheat on the grain growth is greater.When the drawing speed is increased by 0.02 m/min,the solidification end point moves back about 3 m,and the change of superheat and specific water volume in the secondary cooling zone has no obvious effect on the temperature and central solid fraction.When the superheat is increased from 10℃to 55℃,the equiaxial crystal rate decreases from 43.2%to 9.2%,while the influence of pulling speed and secondary cooling zone specific water volume on the equiaxial crystal rate is not obvious,and the change is less than 8%.Based on the electromagnetic stirring position of the end,an optimization scheme was proposed for the existing process.The superheat was reduced to 10℃,the specific water volume was reduced to 0.16 L/kg,which could effectively improve the equiaxed crystal rate and refine the grains.

关 键 词：42CrMo4 CAFE 工艺参数 凝固传热 凝固组织 

分 类 号：TF777[冶金工程—钢铁冶金]