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Metals and Materials International

, Volume 25, Issue 6, pp 1603–1615 | Cite as

Combined Study on Mold Taper and Corner Radius in Bloom Continuous Casting by FEM Simulation and Trial Experiment

  • Peng LanEmail author
  • Liang Li
  • Zhanpeng Tie
  • Haiyan Tang
  • Jiaquan ZhangEmail author
Article
  • 99 Downloads

Abstract

A plane stress model was developed to study the coupled effect of mold taper and corner radius on the thermal–mechanical behavior of a 250 mm × 280 mm continuously cast bloom for a given special steel. Good agreement was obtained in both shell thickness and the off-corner cracking location from modeling and trial experiment. The results show that increasing mold taper results in the obvious decrease of surface temperature near the corner, while enlarging mold corner radius makes the shell surface temperature at the corner region more even with the mold taper between 0 and 1.5% m−1. It is also found that both the mold corner radius and taper are the key factors influencing the shell crack sensitivity but with different mechanism. For the internal crack, the mold taper takes more dominant effect for its corner radius between 0–10 mm, as the hoop strain at the solidification front decreases with increasing mold taper. For the surface crack, more sensitivity is noticed to the mold corner radius. Increasing mold corner radius leads to the increase of the surface hoop strain in the corner region, almost regardless of mold taper. The proper mold taper and corner radius for the present bloom casting should be 1.0–1.5% m−1 and 15–25 mm respectively.

Graphical Abstract

Keywords

Bloom casting Mold corner radius Mold taper Off-corner crack 

List of Symbols

ρ

Density of steel (kg m−3)

Cceff

Equivalent specific heat (J kg−1 °C−1)

λ

Thermal conductivity (W m−1 °C−1)

T

Temperature (°C)

t

Time (s)

fs

Solid fraction

x

Coordinate along the width direction (m)

y

Coordinate along the thickness direction (m)

hW

Heat transfer coefficient of cooling water in the mold (W m−2 °C−1)

TMC

Temperature of the cold mold wall (°C)

TW

Temperature of the cooling water (°C)

hT

Heat transfer coefficient between the hot mold wall (W m−2 °C−1)

TMH

Temperature of hot the mold wall (°C)

TS

Temperature of the strand surface (°C)

D

Equivalent diameter of the water slot (m)

u

Average velocity of cooling water (m s−1)

μ

Dynamic viscosity (N s m−2)

c

Special heat of the water (J kg−1 °C−1)

hMold

Heat transfer coefficient between mold wall surface and the mold flux (W m−2 °C−1)

DAir

Thickness of air gap (m)

kAir

Thermal conductivity of the air (W m−1 °C−1)

DSol

Thickness of solid flux layer (m)

kSol

Thermal conductivity of the solid flux layer (W m−1 °C−1)

DLiq

Thickness of liquid flux layer (m)

kLiq

Thermal conductivity of the liquid flux layer (W m−1 °C1)

Dgap

Thickness of total flux film (m)

hShell

Heat transfer coefficient between the mold flux and the strand surface (W m−2 °C−1)

\(\dot{\varepsilon }\)

Strain rate (s−1)

α

Thermal liner expansion coefficient (°C−1)

E

Young’s modulus (GPa)

v

Passion’s ratio

ε

Hoop strain

σ

Hoop stress (Pa)

Notes

Acknowledgements

The authors express their thanks to the financial support by National Natural Science Foundation of China (No. 51604021, U1860111, 51874033).

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Copyright information

© The Korean Institute of Metals and Materials 2019

Authors and Affiliations

  1. 1.School of Metallurgical and Ecological EngineeringUniversity of Science and Technology BeijingBeijingChina
  2. 2.Center of Technology & QualityXining Special Steel Co. Ltd.XiningChina

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