Method for manufacturing cast strip

Patent metadata

Field	Value
Publication number	US-11717883-B2
Application number	US-201917278964-A
Country	US
Kind code	B2
Filing date	Oct 3, 2019
Priority date	Oct 3, 2018
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

There is provided a cast strip manufacturing method including: supplying a molten steel stored in a tundish (18) to a molten steel pool portion (16) formed by a pair of rotating cooling rolls (11) and a pair of side dams via an immersion nozzle (20); and forming and growing a solidified shell on a circumferential surface of the cooling roll (11) to manufacture a cast strip (1), in which a Si additive is added to the molten steel in the tundish (18), a Si concentration of the molten steel is adjusted to be within a fixed range, and a temperature of the molten steel in the tundish (18) is controlled to be within a fixed range.

First claim

What is claimed is:

1. A cast strip manufacturing method comprising:
supplying a molten steel stored in a tundish to a molten steel pool portion formed by a pair of rotating cooling rolls and a pair of side dams via an immersion nozzle; and
forming and growing a solidified shell on a circumferential surface of the cooling roll to manufacture a cast strip,
wherein a Si additive is added to the molten steel in the tundish, a Si concentration of the molten steel is adjusted to be within a fixed range, and a temperature of the molten steel in the tundish is controlled to be within a fixed range,
wherein a plurality of Si-containing materials having different Si contents are prepared,
and to the molten steel in the tundish, a single Si-containing material or a plurality of the Si-containing materials of which a blending ratio is adjusted are added as the Si additive, and
wherein a difference between a Si concentration of the molten steel supplied to the tundish and a target Si concentration of the cast strip is set within a range of 0.5 mass % to 1.0 mass %,
wherein an addition rate of the Si additive is adjusted according to the blending ratio of the plurality of Si-containing materials so as to satisfy Expression (3),

100
×

Q
s

Q
m

=

ΔC
×

∑
í

(

m
⁡
(
i
)

1
⁢
0
⁢
0

×
Δ
⁢

Q
⁡
(
i
)

)

(
3
)

where
Qs: Addition rate (kg/min) of Si additive,
Qm: Molten steel throughput (kg/min),
ΔC: Difference (mass %) in Si concentration insufficient with respect to target Si concentration,
m(i): Blending of Si-containing material “i” in Si additive (mass %), and
ΔQ(i): Addition ratio (mass %) based on molten steel required for increasing Si concentration by 1 mass % by singly adding Si-containing material “i”.

2. The cast strip manufacturing method according to claim 1 ,
wherein the Si additive is added to the molten steel in the tundish after being heated to a temperature exceeding room temperature.

3. The cast strip manufacturing method according to claim 1 ,
wherein the Si additive is added to the molten steel in the tundish after being heated to a temperature exceeding room temperature.

Assignees

• Nippon Steel Corp

Inventors

• Yoshida Naotsugu

Classifications

• B22D11/108 Primary

  Feeding additives, powders, or the like · CPC title

• B22D11/0622 Primary

  formed by two casting wheels · CPC title

• B22D11/0682

  by cooling the casting wheel · CPC title

• B22D11/06

  into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars · CPC title

• B22D1/00

  Treatment of fused masses in the ladle or the supply runners before casting {(for continuous casting B22D11/10; metallurgical processing, e.g. refining of iron or other metal C21, C22, C25C)} · CPC title