Numerical Simulation of the Growth and Removal of Inclusions in the Molten Steel of a Two-Strand Tundish

Abstract

In the current article, the growth of inclusions by turbulent collision and their removal in the molten steel of a two-strand tundish was calculated. The fluid flow was coupled with heat transfer and the concentration field of inclusions in the tundish. The weir and dam was effective to control the strong stirring energy within the inlet zone. The collision among inclusions in the inlet zone was far stronger than that in other zones. The rising velocity of 9.2-lm inclusions was far smaller than the flow velocity; thus, small inclusions followed the fluid flow well. The concentration of 4-lm, 5-lm, and 9.2-lm inclusions at the outlet were 9.9 ppm, 9.1 ppm, and 30.2 ppm, respectively. The concentration of other inclusions was within 2.0 ppm-6.0 ppm. The total oxygen of the molten steel at the outlet after reaching the steady state was 38.5 ppm assuming all inclusions were alumina. The removal fraction considering turbulent collision growth was 23.0% more than that without considering collision growth.

A Study on the Nonmetallic Inclusion Motions in a Swirling Flow Submerged Entry Nozzle in a New Cylindrical Tundish Design

“…For the inclusion motion in tundish, studies have been carried out to investigate the inclusion removal under the effects of various factors such as flow control devices, tundish geometries, gas bubbling rates, and inclusion sizes. [1][2][3][4][5][6][7][8] After inclusions move from the tundish into the SEN, their deposition on the SEN wall can lead to nozzle clogging. In order to understand the deposition location and mechanism, computational fluid dynamics (CFD) studies have been carried out to investigate the inclusion transport in turbulent steel flows and its deposition on the SEN walls.…”

Microstructure of Non‐Metallic Inclusions Identified in Cast Steel 42CrMo4 after Metal Melt Filtration by Novel Foam Filters

“…The axle fracture was associated to large agglomerated non‐metallic inclusions, which were probably formed during the casting process from smaller endogenous non‐metallic inclusions. Therefore, especially for long‐lifetime safety components it is crucial to improve the cleanliness of the steel melts …”

“…Therefore, especially for long-lifetime safety components it is crucial to improve the cleanliness of the steel melts. [13] Non-metallic inclusions are subdivided into exogenous and endogenous inclusions. According to Apelian and Choi [14] exogenous inclusions arise from, e.g., refractory linings, endogenous inclusions are introduced into the steel melt, e.g., by deoxidation or reoxidation.…”

Numerical Simulation of Transient Multiphase Flow in a Five-Strand Bloom Tundish during Ladle Change

“…During the ladle change of the continuous casting process, minimizing the negative effects at the transient casting stage is a challenge faced by the world's metallurgists [4,5]. At present, most numerical investigations of the tundish have only considered the steady casting process using flow field modeling.…”

“…The Computational Fluid Dynamics (CFD) results were verified using a water model experiment with Laser Doppler Anemometry (LDA) and Digital Particle Image Velocimetry (DPIV) measurements. Zhang et al [4,[9][10][11] studied fluid flow, heat transfer, and inclusion removal in a 2-strand 60 t slab tundish in the steady state and transient state by isothermal and non-isothermal numerical simulations . This study included cast start, sudden cast stop, ladle change, and the sudden closing of one strand, and gives us some valuable information on improving the cleanliness of molten steel.…”