摘要
针对不锈钢板坯轧材经常出现的夹渣和表面翘皮现象,以实际生产条件为背景,对其连铸结晶器内钢液流动行为与水口工艺的相关性进行了试验研究。基于相似原理建立了相似比0.65∶1的物理模型,对不同浸入式水口结构和浇注工艺参数下的结晶器液面状态进行了流体动力学行为评价与比较优化。其中,主要研究了拉速、浸入深度、水口倾孔倾角(4°、8°、15°)、侧孔形状(矩形、倒梯形)等对结晶器内液面波动和表面流速的影响。结果表明,连铸拉速和水口浸入深度对液面波动的影响比水口结构显著;水口上倾角由4°增大到8°、15°,结晶器表面流速有减小趋势,但因流股冲击深度减小,导致在结晶器弯月面处的波高增大。综合表明,针对实际连铸拉速1.10 m/min的需要,其适宜的水口结构为倒梯形水口侧孔、上倾8°,其在水口浸入深度110~120 mm范围内,液面平均波高为1.1~1.2 mm,平均表面流速约为0.103 m/s。同时用数值模拟方法比较了优化方案和原方案,同样表明优化方案液面较平稳,剪切卷渣概率较低。
Aiming at the phenomena of mold powder involvement and warping defects in the surface of stainless steel strip products, the correlation between the flow behavior of molten steel in the continuous casting mold and the involved process parameters of submerged entry nozzle was experimentally studied based on the actual production conditions. A water model of geometrical ratio 0.65∶1 was set up based on similarity principle, and the hydrodynamic behavior of mold liquid level under different submerged entry nozzle structures and casting process parameters was evaluated and optimized. The effects of casting speed, nozzle immersion depth, side port upward angle(4°, 8°, 15°) and nozzle port shape(rectangular and inverted trapezoid) on the mold level fluctuation and surface velocity were studied experimentally. The results show that the influence of casting speed and immersion depth on liquid level fluctuation is greater than that of nozzle structure. The increase in casting speed and the decrease in nozzle immersion depth aggravate the fluctuation of liquid level in the mold obviously. With the nozzle upward angle increasing from 4° to 8° and 15°, the flow velocity on the mold surface tends to drop, and the jet flow impact depth decreases, which results in an increasing mold level fluctuation at the meniscus. It has been revealed that the appropriate nozzle structure is an inverted trapezoidal one with upward angle of 8°. At casting speed of 1.10 m/min and nozzle immersion depth of 110-120 mm with the recommended nozzle, its measured wave height of mold liquid level is 1.1-1.2 mm and the average surface velocity is around 0.103 m/s. Meanwhile, the optimized scheme is compared with the original scheme by numerical simulation, showing that the liquid level of the optimized scheme is relatively stable and the probability of the shearing slag entrapment is low.
作者
刘颜彬
唐海燕
王凯民
马钰
尚广浩
张力萍
张家泉
LIU Yan-bin;TANG Hai-yan;WANG Kai-min;MA Yu;SHANG Guang hao;ZHANG Li ping;ZHANG Jia-quan(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Henan Xinjinhui Stainless Steel Industry Co.,Ltd.,Xuchang 461000,Henan,China)
出处
《连铸》
2022年第3期1-10,17,共11页
Continuous Casting
关键词
板坯结晶器
物理模拟
浸入式水口
液面波动
表面流速
数值模拟
slab mold
physical modelling
submerged entry nozzle
level fluctuation
free surface velocity
numerical simulation
