Effect of SEN immersion depth on mold flow profile and slag entrapment during continuous casting of steel

Mallikarjuna Rao P,Balachandran G,Vaibhav Vasantrao Chougale,Rajendra T,Satish Kumar D

doi:10.30544/653

Mallikarjuna Rao P, Balachandran G + Show 3 more

Open Access

https://doi.org/10.30544/653

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Abstract

Mold flux entrapment during continuous casting of steel contributes to both surface and sub-surface defects in the final product. Continuous casting operating parameters such as casting speed, SEN immersion depth, SEN port geometry, argon flow, and mold EMS significantly affect the mold flow conditions and flow profile. During continuous casting operation, SEN immersion depth is continuously varied to avoid localized erosion of SEN, and it impacts the flow dynamics in the mold. In the present work, water modeling studies were carried out for a wide range of mold widths (1200-1800 mm) and casting speeds (0.8-1.4 m/min) on a 0.5 scaled down water model to optimize casting speed for different combinations of SEN immersion depth and mold width. Results from water modeling were further validated using nail board studies in the actual plant. A safe operating matrix was identified from these experiments to avoid mold slag entrapment during continuous casting.

Highlights

Ultra-low carbon and interstitial free (IF) steels are widely used in automobiles and appliances due to their excellent deep drawability
Flow patterns obtained under all experimental conditions of water modeling exhibited typical double roll flow where liquid jet exiting submerged entry nozzle (SEN) strikes the narrow face of the mold and splits into two loops
A safe operating window to prevent mold slag entrapment during continuous casting was identified for mold widths 1200, 1400, 1600, and 1800 mm from the results of water modelling and nail board experiments and presented in Figs 15 & 16

Summary

Introduction

Ultra-low carbon and interstitial free (IF) steels are widely used in automobiles and appliances due to their excellent deep drawability. The effect of SEN immersion depth at different casting speeds and mold widths on mold flow profile and mold slag entrapment was investigated using laboratory water modelling studies and validated with nail board experiments at the plant continuous caster. For higher mold widths, surface velocity increased continuously with an increase in casting speed for all SEN immersion depths (Fig 6).

Results

Conclusion