薄板坯连铸漏斗形结晶器内卷渣行为物理模拟  

Physical simulation of slag entrapment behavior in funnel-type mold of thin slab continuous casting

作　　者：刘鹏[1,2] 郑万[1,2] 王君驰 王春锋 高运明[1,2] 叶飞 LIU Peng;ZHENG Wan;WANG Jun-chi;WANG Chun-feng;GAO Yun-ming;YE Fei(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;Hubei Provincial Key Laboratory for New Process of Ironmaking and Steelmaking,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;CSP Hot Rolling Sheet Plant,Baosteel Wuhan Iron and Steel Co.,Ltd.,Wuhan 430083,Hubei,China)

机构地区：[1]武汉科技大学耐火材料与冶金国家重点实验室,湖北武汉430081 [2]武汉科技大学钢铁冶金新工艺湖北省重点实验室,湖北武汉430081 [3]宝钢股份武汉钢铁有限公司CSP厂,湖北武汉430083

出　　处：《中国冶金》2023年第2期80-88,128,共10页China Metallurgy

基　　金：国家自然科学基金资助项目(52174323);武汉科技大学科技创新团队资助项目(2018TDX08)。

摘　　要：针对高拉速下薄板坯连铸结晶器内的液面卷渣问题,建立了1∶1水力学模型,采用水/真空泵油模拟钢/保护渣介质,研究了连铸拉速、水口插入深度、保护渣黏度对漏斗形结晶器内液渣层变化及卷渣行为的影响。结果表明,随着拉速提高,结晶器内液面波高升高,液面高度自窄边向水口方向逐渐降低,液渣层厚度相应由薄变厚,导致结晶器窄边附近钢液裸露;结晶器内窄边至水口之间1/2处波高变化较大、液面流速最大、易发生剪切卷渣。在试验条件下,采用增加水口插入深度、降低最高拉速、适当提高保护渣黏度等方法,使液面速度小于0.486m/s的临界流速、液面波动指数F数小于5.45,可防止结晶器内产生剪切卷渣。然而,这些手段不能避免结晶器内水口附近的旋涡卷渣,这是因为薄板坯连铸钢通量大以及漏斗形结晶器和鸭嘴形水口容易形成负压旋涡造成的。Aiming to solve the problem of slag entrapment in thin slab continuous casting mold under high casting speed process,the effects of casting speed,nozzle insertion depth and mold flux viscosity on the change of liquid slag layer and slag entrapment behavior in funnel-type mold were studied by a 1∶1hydraulic model and using water/vacuum pump oil to simulate steel/mold flux medium.The results show that with the increase of casting speed,the wave height of liquid level in the mold rises,the liquid level height gradually decreases from the narrow side of the mold to nozzle,and the thickness of liquid slag layer changes from thin to thick correspondingly,which leads the molten steel near the narrow side of mold to expose.The wave height at 1/2between the narrow side of mold and the nozzle varies greatly,and the liquid velocity is the largest,which has contributed to shear slag entrapment.Under the experiment conditions,the measures such as increasing the nozzle insertion depth,reducing the maximum casting speed and properly increasing the viscosity of mold flux,can prevent the occurrence of shear slag entrapment in the mold by controlling the liquid level velocity to be less than 0.486m/s and the liquid level fluctuation index F value to be less than 5.45.However,these means can not avoid the occurrence of vortex slag entrapment near the nozzle in the mold because the flux of thin slab continuous casting steel is large and the funnel-type mold and duckbill shaped nozzle are easy to form negative pressure vortices.

关 键 词：薄板坯 漏斗形结晶器 剪切卷渣 旋涡卷渣 物理模拟 

分 类 号：TF777[冶金工程—钢铁冶金]