Simulation of Inclusion Particle Motion Behavior under Interfacial Tension in Continuous Casting Mold

Abstract

Inclusions entrapped by the solidifying front during continuous casting adversely affect the properties of the final steel products. In this study, we investigated the effect of the interfacial tension due to surfactant concentration, particularly sulfur, on alumina inclusion motion behavior during molten steel solidification in a continuous casting mold. A two-dimensional numerical model was developed in Ansys Fluent software to simulate the inclusion motion in a continuous casting mold. Further, the impacts of different values of the alumina inclusion diameter, sulfur concentration, and melt temperature were studied to understand the inclusion motion behavior. The inclusion diameter affected the inclusion distribution throughout the domain. The alumina inclusion entrapment percentage varied in the case of sulfur mixing (using an empirical relationship for modeling). It was found that the removal percentage varied according to the sulfur concentration. The addition of sulfur at concentrations from 10 ppm to 70 ppm resulted in a 4% increase in the removal of alumina inclusions (trapped in the solidifying shell), except for the 100-ppm case. Smaller-sized inclusion particles had a 25% higher chance of entrapment at the top level of the mold. Under the effect of a higher surface tension gradient between inclusions and the melt, the predicted findings show that inclusions were vulnerable to engulfment by the solidification front.

Assessment of Inclusion Removal Ability in Refining Slags Containing Ce2O3

“…For step (1), a great number of studies have focused on the nucleation, motion, collision, and transport of inclusions in secondary refining units by using fundamental water models [37][38][39][40][41][42], mathematical models [43][44][45][46][47], and Computational Fluid Dynamics (CFD) models [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66]. Both the Eulerian approach (the statistical evaluation of inclusion species) and the Lagrangian approach (the evaluation of particles) were used in the models.…”

Physical Model of Inclusions Removal at Static Steel–Slag Interface

“…Inclusion removal is a crucial step in the steelmaking process, and the removal effect directly affects steel quality [1][2][3][4]. At present, the main methods of inclusion removal include gas stirring in ladles [5][6][7][8][9][10], Ruhrstahl-Heraeus treatment [11][12][13][14], slag washing [15][16][17], bubble flotation [18], removal in tundishes [19][20][21][22], and continuous casting mold [23][24][25][26], among others. These methods promote inclusions to float to the slag-steel interface so that the inclusions are more easily removed by refining slag absorption.…”

Advancements in the Understanding of Single‐Bubble Dynamics: Integrated Experimental and Simulation Studies

“…Ladle bottom argon blowing, [9] tundish with gas curtain, [10] and SEN argon blowing are typical applications in this field. However, argon blowing may bring the following problems: 1) large bubbles float near the SEN and push away the slag layer, forming slag eyes; and 2) small bubbles are captured by the solidified billet shell deep into the mold along with the molten steel, [11,12] leading to subcutaneous bubble defects in the casting billet; and 3) small bubbles with inclusions adhering to them flow with the molten steel flow strands and are then captured by the solidified billet shell, [13][14][15][16][17] leading to cracks in the final product. Therefore, an in-depth understanding of the size distribution and spatial distribution of bubbles will help to improve the surface and internal quality of steel.…”