Transient Thermo-fluid and Solidification Behaviors in Continuous Casting Mold: Oscillation Behaviors

Abstract

A computational model of the continuous casting process has been developed, which includes transient heat transfer, multiphase flow, solidification, and mold oscillation. Succeeding the previous report on the evolution phenomena in the mold, this article describes fluctuations in the pressure, heat flux, and slag films during the oscillation cycle and the coupling effect of these variables on slag flow and shell growth. The results show that the predicted flux pressure is decided by the combined effect of mold velocity and liquid film thickness. The presence of slag rim enhances the nonuniform pressure flow near the meniscus during mold oscillation. Increases in pressure and heat flux occur in the negative strip time while the mold and slag rim move downwards approaching the lowest position, which squeezes the slag flow to be divided into two tributaries, promoting the slag infiltration and the initial shell solidification. Negative consumption rate is identified partly in the cycle based on the velocity distributions of liquid slag. The model provides quantitative analysis regarding the influence of meniscus shape and slag films related to the casting speed on slag consumption and oscillation mark formation.

Numerical Simulation on Multiple Physical Fields Behaviors in Billet Continuous Casting with Different Stirrer Positions

“…The air part is divided into tetrahedral meshes, and the rest into hexahedral meshes. [10,11,13,15,21,25] To investigate the influence of the stirrer position on multiple physical fields behaviors in billet continuous casting process, the stirrer center position is moved from Y ¼ 515 to Y ¼ 815 mm, as shown in Figure 1b.…”

Prediction Model for Degree of Solid-shell Unevenness during Initial Solidification in the Mold

“…[18][19][20] However, the solid-shell unevenness may not precisely coincide with Φ q of the mold, 21) because both phenomena are also affected by other factors including casting speed 21,22) superheat, 4,23) mold lubricant, 3,18,24,25) oscillation conditions and moldlevel fluctuation. 3,21,26,27) Some researchers have attempted to quantify the unevenness of solid-shell by measuring the solidification profile of steel according to the carbon concentration ([C]). Many studies showed that the degree of solid-shell unevenness was large at [C] ≈ 0.1 wt%, [28][29][30][31][32] but some studies showed large solid-shell unevenness even at ultra-low [C].…”

An Approach for Modelling Slag Infiltration and Heat Transfer in Continuous Casting Mold for High Mn–High Al Steel

“…The casting parameters used in this calculation are listed in Table 1. The multiphysics behaviors were solved simultaneously for a period of time to obtain the steady shell growth and slag infiltration [14]. Slag properties are determined by the combinations of individual components, and these properties evolve during the continuous casting process, especially the casting for high Mn-high Al steel due to the steel/slag reaction.…”

“…In our previous work, a numerical model that addresses the limitations of concurrent phenomena in the continuous casting mold, including fluid flow, heat transfer, shell solidification and mold oscillation, was developed [13,14]. The model was successfully used to characterize the slag infiltration phenomena and initial shell solidification during the casting process from cast-start to steady-state.…”