Removal Mechanism of Microscale Non-Metallic Inclusions in a Tundish with Multi-Hole-Double-Baffles

Abstract

To effectively remove microscale inclusions in the tundish, the Multi-Hole-Double-Baffles (MHDB), a novel flow control device in the tundish for continuous casting, was developed. The hole array mode of the MHDB will directly affect the trajectories of the inclusions. The effect and removal mechanism of the inclusions with sizes of 1 µm to 50 µm in the tundish with MHDB were studied by numerical simulation. The hole array mode of MHDB could affect the inclusions' trajectories and distribution, and the mechanism underlying the effect of the MHDB was investigated using the discrete phase model (DPM). A 1:2.5 physical model was built to verify the accuracy of numerical simulation. The results showed that micro-inclusions were primarily driven by the drag force exerted by the molten steel flow, micro-inclusion trajectories followed the molten steel streamlines almost exactly, but buoyancy still played a role in the removal of the micro-inclusions near the molten steel surface; the hole array mode affected the trajectories of the micro-inclusions and controlled and decelerated the flow of molten steel, increasing the residence time of the molten steel flow a the value that is 15 times larger than the theoretical value; and "upper-in-lower-out" type MHDB showed the most efficient removal of micro-inclusions, with the removal rate being increased by 13-49% compared to the removal rates for the other type MHDB. The results of numerical simulation were well verified by physical simulation.

A Simulation Study on the Flow Behavior of Liquid Steel in Tundish with Annular Argon Blowing in the Upper Nozzle

“…where C is the concentration of the tracer, in kg•m 3 ; D eff is the effective diffusion coefficient, in m 2 •s −1 ; D 0 is the molecular diffusion coefficient in m 2 •s −1 , and its value is 0; and Sc t is the turbulent Schmidt number and its value is 0.7.…”

“…It also distributes liquid steel and, more importantly, facilitates the removal of inclusions and then purifies the liquid steel. Many techniques have been adopted in the tundish to remove inclusions such as retaining walls and dams, diversion walls, tundish filtering, and electromagnetic stirring [1][2][3][4]. Moreover, the argon blowing in the tundish could effectively reduce the amount of the inclusion and purify the liquid steel.…”

Numerical Analysis of RTD Curves and Inclusions Removal in a Multi-Strand Asymmetric Tundish with Different Configuration of Impact Pad

“…The last point where the amount of non-metallic inclusions in the steel melt can be modified during continuous casting is mainly the tundish. Therefore, a number of studies are devoted to the optimization of the flow in the tundish using different weirs and dams [17][18][19][20][21][22][23][24][25], impact pads (e.g., [26,27]), ladle shroud [28], or argon injection [29][30][31]. To study the steel flow, the authors usually utilize the knowledge of experimental measurements or modelling methods, both physical and numerical (e.g., [32]).…”

Numerical Simulation of an Industrial‐Scale Prototypical Steel Melt Tundish Considering Flow Control and Cleaning Strategies

“…Reviews summarizing the physical and mathematical modeling of continuous casting systems show the importance of numerical simulation in this research field . Further publications study different aspects concerning tundish or flow‐controlling designs and inclusion behavior …”