Two-phase analysis of interface level fluctuation in continuous casting mold with electromagnetic stirring

Abstract

Purpose This investigation aims to analyze the steel-flux interface level fluctuation because of electromagnetic stirring and its process parameters in a continuous casting billet mold. Design/methodology/approach An un-coupled numerical model for electromagnetic field generation and a coupled numerical model of electromagnetic field and two-phase fluid flow have been developed. The two-phase fluid flow has been modeled using volume of fluid method, in which externally generated time-varying electromagnetic field is coupled and analyzed using magnetohydrodynamic method. Top surface standing wave stability criteria are used to study the criticality of interface stability. Findings Results show that application electromagnetic field for stirring increases the interface level fluctuation, specifically at the mold corners and near the submerged entry nozzle. The increase in current intensity and stirrer width barely affect the interface level. However, interface level fluctuation increases considerably with increase in frequency. Using stability criteria, it is found that at 20 Hz frequency, the ratio of height to wavelength of interface wave increases much above the critical value. The iso-surface of the interface level shows that at 20 Hz frequency, mold flux gets entrapped into the liquid steel. Practical implications The model may be used during optimization of in-mold electromagnetic stirrer to avoid mold flux entrapment and control the cast quality. Originality/value The study of mold level fluctuation in the presence of in-mold electromagnetic stirrer has rarely been reported. The criticality of stirrer process parameters on level fluctuation has not been yet reported. This study lacks in experimental validation; however, the findings will be much useful for the steelmakers to reduce the casting defects.

Influence of M-EMS on Fluid Flow and Initial Solidification in Slab Continuous Casting

“…Wang et al [15] developed a 3-D coupled model considering electromagnetic field, flow field, heat transfer and level fluctuation under different EMS positions in continuous billet mold, and found that the velocity and wave height at steel/slag interface decreases under lower stirrer position. Maurya et al [16][17][18] analyzed the influence of EMS on flow and solidified shell under different EMS currents and frequencies. However, little research considered the influence of EMS on the flow and initial solidification on slab.…”

Effect of casting speed on solidification and inclusion motions in bloom mold caster under the influence of in-mold electromagnetic stirring

“…This is so because EMS drastically alters the molten steel flow pattern inside the mold at low and medium casting speeds. When EMS is used at a higher casting speed, the meniscus level fluctuations are more significant (Maurya and Jha, 2018), decreasing the removal of low-density inclusions from the mold. However, the removal rate for high-density inclusions is seen to increase compared to without EMS cases.…”

“…The fluid flow in the mold rotates as a result of the Lorentz force, which is a rotational force. Maxwell’s equations are used to simulate the EM field expressed as (Lax and Nelson, 1976; Maurya and Jha, 2018): …”

Online tool based on Tundish steel CFD model to monitor and minimise steel intermix in CC slabs

“…Different approaches are used and detailed in literature to minimize intermixing effects [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. They have been targeted at improving operating conditions and/or layout, even with suitable tools (e.g., particular ladle shroud geometry).…”