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| Periodic behavior and mechanism analysis of inflow of liquid flux around mold meniscus |
| WEI Zi-jian1,2, WANG Xu-dong1,2, YANG Zheng-xue1,2, LIN Guo-qiang1, YAO Man1,2 |
1. School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China;
2. Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province), Dalian University of Technology, Dalian 116024, Liaoning, China |
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Abstract Grasping the mechanism and control factors of the periodic inflow of liquid mold flux at the meniscus with the mold oscillation is the premise of stabilizing and improving the surface quality of continuous casting slabs. Considering the geometry, contact, and motion characteristics of the molten steel-slag-air three-phase in the meniscus region, a mathematical model coupling molten steel heat transfer, shell solidification, and liquid flux flow are established. The predicted results are consistent with actual measurements and related reports, and the transient periodic flow and inflow behavior of liquid flux are simulated and analyzed. Focusing on the main factors affecting the inflow and consumption of mold flux, the periodic behavior of liquid flux inflow is studied. The variation characteristics of liquid flux inflow, inflow velocity, and slag channel width in one oscillation cycle are discussed. The influencing factors and mechanism of dominant liquid flux inflow are analyzed by defining and analyzing the contribution and regular characteristics of liquid flux inflow from different area around the meniscus. The results show that in one oscillation period, the inflow process of mold flux into the slag channel is divided into two stages and two transition states. In the first stage, the inflowing liquid flux is mainly provided by the area close to the top of the molten steel on the meniscus. In the second stage, the inflowing liquid flux is provided by the area near the slag rim. In the transition state, the amount of liquid flux flowing into the slag channel in the two regions is a process of one ebbing and the other growing. In the meniscus area, the horizontal velocity is the main factor restricting the liquid flux flowing into the slag inlet or away from the slag inlet, and the vertical velocity is the key to affecting the liquid flux inflow region and the transient inflow, and the transient inflow is jointly affected by the vector velocity component and the width of the slag channel. Under this simulation condition, the liquid flux flows into the slag channel throughout the oscillation cycle, the peak value of inflow is in the middle of the positive strip, and the valley of inflow is between the middle of the negative strip and the end of the negative strip.
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Received: 12 October 2022
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2023, Vol. 58 
