Method for continuously casting steel
View Patent ↗A primary object of the present invention is to provide a technique of avoiding occurrence of surface defects caused by an electromagnetic brake while checking internal defects with this electromagnetic brake, so that cleanliness of a cast steel can be improved compared with prior arts, and the present invention provides a method for continuously casting steel, the method comprising supplying molten steel into a mold while applying an electromagnetic brake to an outlet flow discharged from an outlet port of an immersion nozzle, wherein magnetic flux density (B) of the electromagnetic brake is within a range of the following (Formula 1): B min ≤ B ≤ B max , B min = 800 · ( D max D 0 ) 3 · ( H SEN H 0 ) ( v · sin θ ) , and B max = 3000 · ( D max D 0 ) 3 · ( H SEN H 0 ) ( v · sin θ ) 2 . ( Formula 1 )
1. A method for continuously casting steel, the method comprising supplying molten steel into a mold while applying an electromagnetic brake to an outlet flow discharged from an outlet port of an immersion nozzle,
wherein magnetic flux density (B) of the electromagnetic brake is within a range of the following (Formula 1):
B
min
≤
B
≤
B
max
(
Formula
1
)
wherein
B
min
=
800
·
(
D
max
D
0
)
3
·
(
H
SEN
H
0
)
(
v
·
sin
θ
)
,
B
max
=
3000
·
(
D
max
D
0
)
3
·
(
H
SEN
H
0
)
(
v
·
sin
θ
)
2
,
D 0 = a mold thickness (m) of the mold having short sides and long sides on a horizontal cross-sectional shape, the mold thickness measured as a distance between the long sides facing each other in the mold at ends of the long sides,
D max = a maximum value of a mold thickness (m) of the mold having the short sides and the long sides on the horizontal cross-sectional shape, the maximum value measured as a distance between the long sides facing each other in the mold at a middle of each long side,
H 0 = a distance (m) between a surface of the molten steel and a center of an electromagnetic brake coil in a vertical direction,
H SEN = a distance (m) between a bottom surface of the immersion nozzle and the center of the electromagnetic brake coil in the vertical direction,
v = a flow velocity (m/s) of the molten steel discharged from the immersion nozzle, and
θ= an outlet flow angle(°) of the molten steel, wherein the flow velocity v of the molten steel is 0.685 m/s to 0.799 m/s.
2. The method for continuously casting steel according to claim 1 , wherein a rectangular mold that has short sides and long sides on a horizontal cross-sectional shape is used as the mold.