摘要
为了优化超大圆坯连铸结晶器的冶金效果,搭建了1∶1的超大圆坯(≥φ800 mm)结晶器水模拟平台。通过观测液面波高、监测表面平均流速、墨汁显示流场试验、水油模拟卷渣试验等手段,对不同浸入式水口结构和工艺参数导致的结晶器内流场和液面行为进行定量和定性评估。结果表明,随着水口侧孔倾角不断向下,自由液面流速逐渐减小,模拟卷渣情况也逐渐减轻,但侧孔倾角向下15°时自由液面过于平静。当侧孔倾角向上15°时,在结晶器中部到结晶器壁区域内的液面均较为活跃,同时也伴随着较为严重的液面裸露及卷渣状况。对侧孔跑道形、圆形、倒梯形和矩形外扩型对比分析可知,圆形侧孔会使流股集中导致自由液面流速和波高远大于其他侧孔形状的水口,也会导致十分严重的卷渣以及液面裸露现象,其卷渣时长所占比例可高达98%。而矩形外扩型侧孔使得流股较为发散,令自由液面流速较小且结晶器中部区域波高较高,可以使自由液面在较大区域内波动活跃同时不会出现液面裸露状况,其卷渣时长所占比例仅为27%。同时矩形外扩型水口的液面流速随着拉速的增大变化不明显。五孔矩形外扩型侧孔向上15°对于超大圆坯结晶器内的钢液流动状态控制效果远优于当前使用的五孔侧孔跑道形向上15°水口,更有利于铸坯的表面质量和内部质量控制。
In order to optimize the metallurgical effect of the super large round bloom continuous casting mold,a full-scale large round bloom(≥ϕ800 mm)mold water modeling platform was established.Under a fixed immersion depth,the flow field and liquid level behavior in the mold due to different submerged entry nozzle(SEN)structures were quantitatively and qualitatively evaluated by observing the liquid level fluctuation,monitoring the average surface velocity,and conducting ink display flow field and water-oil simulated slag entrapment experiments.The results show that the free liquid surface velocity decreases gradually with the SEN port angle continuously downward,and the simulated slag entrapment situation also decreases gradually,but the free liquid surface is too calm when the SEN angle is downward 15°.When the SEN angle is upward 15°,the liquid level in the area from the middle of the mold to the mold wall is more active,accompanied by more serious liquid surface exposure and slag entrapment situation.The SEN with runway,round,inverted trapezoidal and rectangular flared side port shapes were analysed.It can be seen that the SEN with round port shape will make the jet concentrated,resulting in the surface velocities and level fluctuations are much larger than the other SEN port shapes,but also lead to a very serious slag entrapment and liquid surface exposure phenomenon,the slag entrapment of the length of the time proportion can be as high as 98%.However,the rectangular flared shape makes the jet more dispersed so that the surface velocities are small,and the level fluctuations in the middle region of the mold are high.The free liquid surface can be active in a large area without liquid surface exposure,and the slag entrapment occurs only 27%of the time.At the same time,the liquid surface flow rate of the rectangular flared nozzle does not change significantly as the casting speed increases.The five-port rectangular flared shape with a 15°upwards are much better for controlling the flow of molten steel in a super large round bloom mold than the five-port runway shape with a 15°upwards currently in use.It is more conducive to the surface quality and internal quality control of the bloom.
作者
陈希青
白云
王璞
王鹏
肖红
沈毓
张家泉
CHEN Xiqing;BAI Yun;WANG Pu;WANG Peng;XIAO Hong;SHEN Yu;ZHANG Jiaquan(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Jiangyin Xingcheng Special Steel Co.,Ltd.,Jiangyin 214429,Jiangsu,China;Hunan Zhongke Electric Co.,Ltd.,Yueyang 414000,Hunan,China)
出处
《钢铁》
CAS
CSCD
北大核心
2024年第4期85-95,115,共12页
Iron and Steel
基金
国家自然科学基金资助项目(U1860111)
湖南省科技人才托举工程资助项目(2023TJ-Z14)。
关键词
超大圆坯
水模拟平台
侧孔角度
侧孔形状
流动状态
卷渣
结晶器
super large round bloom
water modeling platform
SEN port angle
SEN port shape
flow state
slag entrapment
mold
