摘要
连铸过程结晶器内保护渣的卷入是连铸坯大颗粒夹杂物的主要来源之一,也是造成连铸坯表面质量缺陷的重要原因。本研究基于某钢厂断面为1300 mm×230 mm的板坯连铸结晶器,建立了耦合大涡模拟湍流模型、VOF多相流模型和离散相模型的三维数值模型,研究了结晶器内钢液-渣相-空气相-氩气瞬态多相流动行为。并且通过用户自定义子程序定量预测了弯月面卷渣的发生以及卷入渣滴在结晶器内尺寸、个数以及空间位置随时间的变化。结果表明,在当前1.4 m/min拉速、160 mm水口浸入深度和6 L/min吹氩流量(塞棒加上水口)下流态为典型的双环流流态,钢液射流与氩气泡之间的相互作用使得结晶器内氩气泡的空间分布呈现扇形分布。弯月面净卷渣速率为0.00524 kg/s,且卷渣主要发生在结晶器宽度1/4及距水口中心结晶器宽度方向130 mm附近,分别由上环流对弯月面的剪切作用和水口附近复杂流动造成的漩涡引起。结晶器内卷入渣滴的个数呈现瞬态变化,大部分卷入渣滴的直径在2~5 mm之间,密度的差异使得大部分卷入的渣滴最终会重新上浮至渣层。
The slag entrainment during the continuous casting(CC)process is one of the primary sources of large inclusions in CC slabs,and it is also a significant factor causing surface quality defects.In the current study,a three-dimensional numerical model based on an actual 1300 mm×230 mm slab CC mold was established.The molten steel-slag phase-air phase-argon gas transient multiphase flow inside the mold was investigated by coupling the large eddy simulation turbulent model,VOF multiphase flow model,and discrete phase model.Moreover,the occurrence of the slag entrainment on the meniscus and the variation of the size,number,and spatial distribution of slag droplets were quantitatively predicted using a user defined function.The results indicate that the flow pattern in the mold was a typically double roll flow with the current 1.4 m/min casting speed,160 mm immersion depth of the submerged entry nozzle,and 6 L/min argon flow rate(stopper rod and upper nozzle)condition.The interaction between the jet flow and argon bubbles resulted in a fan-shaped distribution of argon bubbles inside the mold.The net slag entrainment rate on the meniscus was 0.00524 kg/s.The slag entrainment occurred primarily near the 1/4 width of the mold and 130 mm away from the nozzle center in width direction of the mold,which was induced by the shear effect of the upper circulation flow and the vortex generated by the complex flow,respectively.The number of entrained slag droplets inside the mold exhibited transient variations,with most droplets having diameters between 2-5 mm.Density differences resulted in most entrained droplets ultimately refloating to the slag layer.
作者
吕剑波
刘风刚
陈威
左康林
邓伟
王少义
张立峰
LÜJianbo;LIU Fenggang;CHEN Wei;ZUO Kanglin;DENG Wei;WANG Shaoyi;ZHANG Lifeng(Beijing Shougang Co.,Ltd.,Tangshan 063009,Hebei,China;School of Mechanical and Materials Engineering,North China University of Technology,Beijing 100144,China;Shanghai Meishan Iron and steel Co.,Ltd.,Nanjing 210039,Jiangsu,China;Nanjing Iron and Steel Co.,Ltd.,Nanjing 210035,Jiangsu,China;Wuyang Iron and Steel Co.,Ltd.,Wuyang 462500,Henan,China)
出处
《连铸》
北大核心
2025年第2期91-99,共9页
Continuous Casting
关键词
弯月面卷渣
卷渣速率
多相流动
数值模拟
板坯连铸
meniscus slag entrainment
slag entrainment rate
multiphase flow
numerical simulation
slab continuous casting
