利用射钉法测量240mm×240mm铸坯凝固坯壳厚度及工艺优化  

Measurement of Solidified Shell of 240mm×240mm Casting Bloom by Nail-Shooting Technique and Process Optimization

作　　者：秦凤婷[1] 刘宗辉 董战利 Qin Fengting;Liu Zonghui;Dong Zhanli(Metallurgy&Chemical Industry Department,Jiyuan Vocational Technical College,Jiyuan 459000;Metallugical School,Northeast University,Shenyang 110819;Steelmaking Plant,Henan Jiyuan Iron&Steel(Group)Co Ltd,Jiyuan 459000)

机构地区：[1]济源职业技术学院冶金化工系,济源459000 [2]东北大学冶金学院,沈阳110819 [3]河南济源钢铁(集团)有限公司炼钢厂,济源459000

出　　处：《特殊钢》2020年第1期51-54,共4页Special Steel

摘　　要：利用射钉法测定了连铸机生产240mm×240mm断面35CrMoA、20CrMoA、GCr15、60Si2MnA四个钢种的铸坯凝固坯壳厚度,并根据凝固定律计算了其液相穴长度和综合凝固系数;针对240mm×240mm方坯选择固相率0.70、0.75进行计算得出F-EMS在不同拉速条件下的电磁搅拌位置,分析了工艺参数对连铸机凝固系数的影响,提出的工艺优化措施为:改变电磁搅拌位置,F-EMS位置修正为根据高碳钢GCr15、60Si2MnA来安装,35CrMoA,20CrMoA,GCr15和60Si2MnA四钢种拉速值分别调整为0.80、0.81、0.78、0.80 m/min。工艺优化后铸坯质量得到明显改善,中心偏析级别≤0.5合格率由原来≤40%提高到100%,中心疏松级别≤1.5合格率由原来≤50%提高到≥90%。Nail-shooting technique is applied to measure shell thickness of 240mm×240mm bloom of steel 35CrMoA,20CrMoA,GCr15 and 60Si2MnA produced by the continuous caster.Length of the liquid core and solidification coefficient are calculated by using the solidification law.The electromagnetic stirring position of F-EMS at different drawing speeds is calculated by the solid phase ratio of 0.70 and 0.75 for the 240mm×240mm bloom.The relationship between solidification coefficient of continuous casting machine and each process parameter is analyzed.The process optimization measures are:changing the electric stirring position,and modifing the F-EMS position to install according to high carbon steel GCr15 and 60Si2MnA,and adjusting the casting speed value of four steel of 35 CrMoA,20CrMoA,GCr15 and 60Si2MnA to 0.80,0.81,0.78 and 0.80 m/min.The quality of billet is improved greatly after the process improvement,i.e.qualified ratio of center segregation rating≤0.5 increases from original≤40%to 100%and that of center porosity rating≤1.5 increases from original≤50%to≥90%.

关 键 词：射钉法 240mm×240mm方坯连铸 末端电磁搅拌 综合凝固系数 

分 类 号：TF777[冶金工程—钢铁冶金]