Numerical Simulation for Two‐Phase Flow, Heat Transfer, and Inclusion Transport in Bloom Mold Considering the Effects of Argon Gas Injection and Mold Electromagnetic Stirring

Abstract

During the continuous casting process, the fluid flow is a critical factor that affects the heat transfer and the inclusion transport, which, in turn, determines the final quality of steel products. Argon gas injection (AGI) is widely employed to prevent submerged entry nozzle (SEN) clogging in the slab mold. [1,2] After entering the mold, argon bubbles alter the flow pattern, promote inclusion floating, and improve the melting of mold flux. [1][2][3][4] However, a large amount of argon gas can lead to increased level fluctuations, uneven distribution of mold flux, and even slag entrainment. [1,3,5] Moreover, argon bubbles may be captured by the solidified shell and become surface defects. [6,7] Fortunately, the aforementioned negative effects can be reduced by suitable operating parameters and electromagnetic technologies to meet quality requirements. [2,3,[8][9][10] Because of these beneficial effects, AGI is used in the bloom mold of Hebei Iron & Steel Group Hansteel Company, [11] Angang Steel Company Limited, [12] Nanjing Iron and Steel Company Limited [13] to improve the castability of alloy steels that are prone to clogging. However, due to the small cross-sectional area of the bloom mold, surface defects from captured bubbles are more serious. [12] As a widely used electromagnetic technology, mold electromagnetic stirring (M-EMS) can enhance molten steel flow, [14] promote superheat dissipation, [15] and improve the equiaxed crystals ratio, [16] more importantly, it can reduce bubbles captured by the solidified shell in the slab mold [17][18][19] and the bloom mold. [12] Despite these advantages of M-EMS, the double action of M-EMS and AGI may cause more level fluctuations, which has been reported in the slab mold [20] but not in the bloom mold. Therefore, to provide theoretical guidance for quality improvement and AGI application, it is essential to investigate the effects of AGI and M-EMS on fluid flow, temperature distribution, and inclusion removal in the bloom mold.Many experimental researches have been performed to investigate the two-phase flow of molten steel and argon gas in the SEN and mold regions using water models [21][22][23][24][25] and liquid metal models. [26][27][28][29] In the water model, it is easy to capture the twophase flow but difficult to consider the effect of the magnetic field because of the low electrical conductivity of water. Although the liquid metal model can apply the magnetic field, the two-phase flow in the mold is hard to visualize. Thus, numerical simulation is widely used to investigate the two-phase flow in the mold. Several studies investigated the effect of AGI on the flow field, [3,7,[30][31][32][33] temperature distribution, [3,30] initial solidification, [3] inclusion removal, [7,31,33] and slag-steel interfacial behavior, [1,4,5,32]

Numerical Investigation on Coalescence Behavior of Liquid Inclusion Particles in Argon Bubble Wake Flow

“…At present, the bottom air blowing of metallurgical reactor is an effective control method to promote the removal of nonmetallic inclusions from steel, and has been widely used in practical production. [16,17] This study focuses on the dynamic characteristics of bubble flotation and the collision behavior of inclusions within the bubble wake. The aim is to uncover the various factors that influence the coalescence of inclusions.…”

“…At present, the bottom air blowing of metallurgical reactor is an effective control method to promote the removal of nonmetallic inclusions from steel, and has been widely used in practical production. [ 16,17 ]…”

Effect of Permanent Magnet Stirring on Solidification of High‐Sulfur Micro‐Alloyed Steel under Different Magnetic Flux Densities

“…Jiang et al [ 11 ] confirmed that the solute segregation and solidification structure of casting steel bloom were improved by electromagnetic stirring. Xuan et al [ 12 ] found that electromagnetic technology was an effective approach to induce fluid flow and control the inclusions in the molten steel. Thus, it is feasible to introduce an external field to control the MnS precipitation during the solidification process of the steel.…”