JP2000107837A - Short side weir for twin roll type thin plate continuous caster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a good slab even in the case of using gas for preventing the solidification of oil. SOLUTION: A short side weir 10 is formed by a main body 11 having a gas storage chamber 12 and an inside wall bodies 15 closing an opening part of the gas storage chamber 12 and fitted to the main body 1. In the inside wall body 15, lots of spouting holes 16 are formed along the inner part side of an outer peripheral edge 1b of a mold roll 1 and the gas spouting quantity from the spouting hole 16 is constituted so as to be much at the roll kiss part K and be gradually less as going upward. The gas in the gas storage chamber 12 can be spouted toward the inner part side of the outer peripheral edge 1b of the roll from the spouting hole 16 group to push back molten steel A tending to invade into the contacting portion S between the inner surface 10a of the short side weir and the end surface 1a of the roll. The molten steel A can be pushed back in good balance by spouting much at the roll kiss part K and less near the molten steel surface in the spouting quantities W1-Wn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short side weir in a twin roll type sheet continuous casting machine for casting molten steel between a pair of mold rolls to solidify and continuously cast a thin slab.

[0002]

2. Description of the Related Art In a conventional short-side weir, ceramics, a sintered alloy, or the like is fitted in a contact portion between an end of a mold roll and a short-side weir. However, erosion, wear, cracks, and the like occur. In addition, the quality of the product deteriorates due to the generation of the solidified shell.

As a countermeasure against this, Japanese Patent Laid-Open Publication No. 62-12405
No. 3 discloses an arrangement. That is,
Opposite to the roll end face including the roll kiss portion of the mold roll, a porous end face press placed in a non-contact state with the roll end face is provided, so that a gap is provided between the roll end face and the end face press. Have been. And for the gap,
Inert gas is ejected from the end face presser to form a gas film. At this time, the gap between the end face of the short side weir and the roll end face of the mold roll is adjustable (about 0.2 mm).

However, according to this conventional configuration, since the mold roll is cooled and the pool is heated by the molten metal, the gap between the end face of the short side weir and the roll end face of the mold roll cannot be adjusted. It is very difficult and it is difficult to push the molten metal back in a well-balanced manner because the molten metal that is about to enter the gap is a liquid. Further, the amount of the inert gas spouted was small at the roll kiss portion side due to the influence of the molten metal, and the amount was spouted much near the surface of the molten metal, so that a good cast slab (product) could not be obtained.

Therefore, as a new countermeasure, Japanese Patent Laid-Open No.
No. 05233 was provided. That is, the oil is ejected (injected) at a predetermined pressure through the porous member into the gap between the roll end face and the short side weir.

[0006]

However, in the above-described configuration in which oil is jetted into the gap, although there is a certain effect on the prevention of burr generation due to the formation of an oil film,
A problem has arisen in that the oil is seized on the sliding surface of the short side weir and solidifies, and the oil is not ejected uniformly on the entire sliding surface.

Accordingly, the invention according to claims 1 and 3 of the present invention provides a short-side dam for a twin-roll thin-sheet continuous casting machine capable of obtaining a good cast piece while using a gas capable of preventing solidification of oil. It is intended to provide.

[0008]

In order to achieve the above-mentioned object, according to the present invention, a short side weir for a twin roll type thin plate continuous casting machine according to the first aspect of the present invention has molten steel between a pair of mold rolls. In a twin-roll thin-sheet continuous caster that casts and solidifies and continuously casts a thin slab, the short-side dam disposed in contact with the roll end faces of both mold rolls is a gas reservoir that is open to the inner side. A main body having a chamber, and an inner wall body attached to the main body by closing an open portion of the gas reservoir chamber. The inner wall body extends along the inner side of the outer peripheral edge of the mold roll. A large number of ejection ports are formed, and the amount of gas ejected from these ejection ports is configured so that the number of roll kiss portions of the mold roll is large and the amount of the gas is gradually reduced toward the top.

Therefore, according to the first aspect of the present invention, the gas blown into the gas reservoir can be jetted from the jet port group toward the inside of the outer peripheral edge of the roll. Molten steel that tries to penetrate the contact portion with the end face can be pushed back. At this time, the amount of squirt is large at the roll kiss portion and reduced near the surface of the molten metal, so that the molten steel can be pushed back in a well-balanced manner.

According to a second aspect of the present invention, there is provided a short side weir for a twin roll type continuous sheet casting machine according to the first aspect of the present invention, wherein the jet port group is located at an upper portion with respect to a diameter on the roll kiss portion side. It is characterized in that the diameter is gradually reduced.

Therefore, according to the second aspect of the present invention, the gas is blown into the gas reservoir with the set amount of gas, so that the change in the amount of jet in the vertical direction is automatically adjusted based on the change in the diameter of the jet port. obtain.

According to a third aspect of the present invention, there is provided a short roll weir for a twin roll type continuous thin plate casting machine, wherein molten steel is poured between a pair of mold rolls to solidify and continuously cast a thin cast piece. In the mold thin plate continuous casting machine, the short side weir arranged in contact with the roll end faces of both mold rolls closes the main body having the gas reservoir chamber opened to the inner surface side and the opening of the gas reservoir chamber. And a plurality of ejection ports formed along the inner periphery of the outer periphery of the mold roll, and the gas ejected from these ejection ports is formed on the inner wall body. Is characterized in that the blowout pressure of the mold roll is higher at the roll kiss portion of the mold roll and gradually lower at the upper portion.

According to the third aspect of the present invention, the gas blown into the gas reservoir can be jetted from the jet port group toward the inside of the outer peripheral edge of the roll. Molten steel that tries to penetrate the contact portion with the end face can be pushed back. At that time, the jet pressure is set high in the roll kiss portion and low near the surface of the molten metal, so that the molten steel can be pushed back in a well-balanced manner.

According to a fourth aspect of the present invention, there is provided a short side weir for a twin roll type continuous sheet casting machine according to the third aspect of the present invention, wherein the gas reservoir is provided in a vertical direction from a molten metal surface to a roll kiss. , And the gas pressure blown into each of the divided holes becomes higher as approaching the roll kiss portion.

Therefore, according to the fourth aspect of the present invention, the gas is blown into each hole at the set gas pressure, so that the jet pressure from the jet port in each hole becomes the same. It becomes low near the surface of the bath.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
This will be described with reference to FIGS. The twin-roll thin-sheet continuous caster is configured to rotate a pair of mold rolls 1 and 1 facing each other.
During this process, molten steel A is poured and solidified, and a thin cast piece B is continuously cast. Short side weirs 10 are arranged in contact with the roll end surfaces 1a, 1a of both mold rolls 1, 1, respectively.

The short side weir 10 is a main body 1 made of a refractory.
1 and an inner wall 15 provided on the inner side of the main body 11 and made of a refractory material such as ceramics or sintered metal. The main body 11 is formed with a concave gas reservoir 12 which is open to the inner surface side. At this time, the open portion of the gas reservoir 12 is provided with the outer peripheral edges 1b, 1b of the two roll end surfaces 1a, 1a. It is formed in a V-shape so as to include it. An outlet 13 for connecting a gas supply path (pipe, hose) 2 from a gas supply device (not shown) to the gas reservoir 12 is formed on the outer surface side of the main body 11.

The inner wall body 15 is also formed in a V-shape.
The opening of the gas reservoir 12 is closed and attached to the main body 11 by fitting it into a step 14 formed at the open edge of the gas reservoir 12. At that time, the main body 11
And the inner surface of the inner wall body 15 are continuous vertical surfaces, thereby forming the short side weir inner surface 10a. The short side weir 10 is disposed in a state where a contact portion S is generated between the short side weir inner surface 10a and the roll end faces 1a, 1a.

The inner wall body 15 has a large number of injection ports 16 formed along the inside of the outer peripheral edges 1b, 1b (near the boundary between the mold rolls 1, 1 and the molten steel A). The spouts 16 are formed by round holes. At this time, the spouts 16 are configured so that the diameter gradually becomes smaller toward the top of the roll kiss portion K side of the mold rolls 1 and 1. ejection amount of the gas blown from the ejection port 16 group, more ejection amount W ₁ many top of Rorukisu portion K (bath level a side more) gradually reduced, _{i.e., W 1> W 2> W} 3>
...> W _n .

The operation of the above embodiment will be described below. An inert gas (an example of a gas) such as argon or helium from the gas supply device is blown (injected) from the gas supply path 2 via the blow-in port 13 at a gas amount W set in the gas reservoir chamber 12. You. And gas reservoir 1
The inert gas in the nozzle 2 is supplied from the group of jet ports 16 to the outer peripheral edge 1 of the roll.
b, 1b is squirted toward the inner side.
Molten steel A that tries to enter the contact portion S between the short side weir inner surface 10a and the roll end surfaces 1a, 1a can be pushed back.

At that time, the ejection amount W ₁ of the roll kiss portion K is large and gradually decreases toward the top, that is, W ₁ >
Since the configuration is such that W ₂ > W ₃ >... >> W _n , the amount of jet at the roll kiss portion K is large and the jet is small near the surface of the molten metal a. The mold rolls 1, 1 and molten steel A
Thus, the formation of a solidified shell can be prevented by stirring the boundary portion, and a good slab B without burrs can be obtained.

As described above, the inert gas is supplied to the gas reservoir 12.
By blowing with the gas amount W set inside, the ejection amount W _1-
Changes in the vertical direction of the W _n may automatically adjusted based on the diameter change of the ejection port 16 group. Further, since the inert gas is ejected, solidification due to oil baking can be prevented, and the molten steel A can be pushed back in a well-balanced manner, so that the adjustment of the gap of the contact portion S does not require much precision. , Easy to do.

Next, another embodiment of the present invention will be described with reference to FIGS.
A description will be given based on FIG. In this alternative embodiment, detailed description of the same components as those in the above-described embodiment will be omitted. That is, in another embodiment, 1 is a mold roll, 1a is a roll end face, 1b
Is a roll outer peripheral edge, 20 is a short side weir, 20a is a short side weir inner surface,
21 is a main body, 22 is a gas reservoir, 24 is a stepped portion, 25 is an inner wall, 26 is a spout, A is molten steel, a is a molten metal surface, B is a cast piece, S is a contact portion, and K is a roll kiss portion. , Respectively.

In this alternative embodiment, the gas reservoir chamber 22 is divided into four (plural) in the vertical direction by a partition body 27 integrated with the main body 21 from the molten metal surface a to the roll kiss portion K. Divided into four holes 22A,
22B, 22C and 22D are formed.

The main body 21 has four gas supply passages 2A, 2B, 2C and 2D from the gas supply device, and blow-in ports 23A for connecting the gas supply passages 2A, 2B, 22C and 22D to the respective holes 22A, 22B, 22C and 22D. 23B, 23C and 23D are formed. At that time, the gas supply paths 2A, 2B, 2C,
The gas pressure PA, PB, PC, PD blown from the 2D into each of the holes 22A, 22B, 22C, 22D becomes higher as approaching the roll kiss portion K, that is, PA>
It is configured so that PB>PC> PD. The outlets 26 are all formed with the same diameter.

Hereinafter, the operation of the above-described another embodiment will be described. Inert gas from the gas supply device side is supplied from the gas supply passages 2A, 2B, 2C, and 2D to the blow-in ports 23A, 2B.
3B, 23C, 23D, each hole 22A, 22
B, the gas pressure PA set in each of 22C and 22D,
It is blown by PB, PC, PD. And each hall 22
The inert gas in A, 22B, 22C, 22D is ejected from the group of ejection ports 26 toward the inside of the outer peripheral edges 1b, 1b, and the ejection pressure causes the short side dam inner surface 20a and the roll end surface 1a, The molten steel A trying to penetrate the contact portion S between the molten steel A and the first steel 1a can be pushed back.

At this time, the gas pressures PA, PB, PC, PD
Is configured so as to be higher as approaching the roll kiss portion K, that is, PA>PB>PC> PD. The jet pressure Pa on the part K side is high and the jet pressure Pd near the molten metal surface a is low, so that the molten steel A can be pushed back in a well-balanced manner, and the boundary between the mold rolls 1, 1 and the molten steel A is agitated and solidified. The formation of a shell can be prevented, and a good slab B without burrs can be obtained.

Further, since the inert gas is ejected, solidification due to oil burning can be prevented, and the molten steel A can be pushed back in a well-balanced manner.
The gap can be easily adjusted without requiring much precision. Furthermore, since the group of the ejection ports 26 has the same shape, the whole can be easily manufactured.

In the above-described embodiments, the ejection ports 16,
Although a round hole type is adopted as 26, this may be a square hole type such as a square or a slit type.

[0030]

According to the first aspect of the present invention, the gas blown into the gas reservoir is blown out, and the gas is blown into the contact portion between the inner surface of the short side weir and the roll end surface. Since the molten steel is pushed back, solidification due to oil baking can be prevented, and at this time, the amount of squirting is large at the roll kiss part and reduced near the molten metal surface, so that the molten steel can be pushed back in a well-balanced manner and the mold The boundary between the roll and molten steel can be agitated to prevent the formation of a solidified shell, to obtain a good slab without burrs, and to adjust the gap at the contact part without much precision, and easily. It can be carried out.

According to the second aspect of the present invention,
By injecting the gas into the gas reservoir chamber with the set gas amount, the vertical change of the ejection amount can be automatically adjusted based on the diameter change of the ejection port.

[0032] According to the third aspect of the present invention, the gas blown into the pool chamber is blown out, and the blowout pressure causes molten steel to enter the contact portion between the inner surface of the short side weir and the end face of the roll. Is a form that pushes back
Solidification due to oil baking can be prevented, and at that time the jet pressure is high at the roll kiss part and low near the hot water surface,
In addition to being able to push back the molten steel in a well-balanced manner, the boundary between the mold roll and the molten steel can be agitated to prevent the formation of a solidified shell, and a good slab free of burrs can be obtained. The adjustment does not require much precision and can be easily performed.

Further, according to the fourth aspect of the present invention, the gas is blown into each of the holes at a predetermined gas pressure, so that the jet pressure from the jet port of each of the holes becomes the same. In this case, the height can be lowered near the surface of the molten metal. At this time, since the group of jet ports may have the same shape, the whole can be easily manufactured.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of the present invention, and is a front view of a short-side weir for a twin-roll thin-sheet continuous casting machine.

FIG. 2 is a front view of a main part of a short side weir for the twin roll type continuous sheet casting machine.

FIG. 3 is a vertical side view of the short-side weir for the twin-roll thin-sheet continuous casting machine.

FIG. 4 is a cross-sectional plan view of a main part of the short side weir for the twin roll type continuous sheet casting machine.

FIG. 5 shows another embodiment of the present invention and is a front view of a short-side weir for a twin-roll thin-sheet continuous casting machine.

FIG. 6 is a front view of a main part of the short side weir for the twin roll type continuous sheet casting machine.

FIG. 7 is a longitudinal sectional side view of the short-side weir for the twin roll type continuous sheet casting machine.

FIG. 8 is a cross-sectional plan view of a main part of the short side weir for the twin roll type continuous sheet casting machine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Mold roll 1a Roll end surface 1b Roll outer peripheral edge 2 Gas supply path 2A-2D Gas supply path 10 Short side weir 11 Main body 12 Gas storage chamber 15 Inner side wall 16 Spout port 20 Short side weir 21 Main body 22 Gas storage chamber 22A-22D Hole 25 Inner wall body 26 Spout port A Molten steel a Metal surface B Cast slab S Contact area K Roll kiss part W Gas amount W ₁ -W _n Jet amount PA-PD Gas pressure Pa-Pd Jet pressure

Claims (4)

[Claims] 1. A twin-roll type continuous sheet casting machine for casting molten steel between a pair of mold rolls to solidify and continuously cast a thin slab, and is disposed in contact with the roll end surfaces of both mold rolls. The short side weir is formed of a main body having a gas reservoir chamber opened to the inner surface side, and an inner wall body closed to an opening of the gas reservoir chamber and attached to the main body. A large number of ejection ports are formed along the inner side of the outer peripheral edge of the mold roll, and the ejection amount of gas ejected from these ejection ports is such that the number of roll kiss portions of the mold roll is large and the upper portion thereof is gradually reduced. A short side weir for a twin roll type continuous sheet casting machine, comprising: 2. A short side weir for a twin roll type continuous sheet casting machine according to claim 1, wherein the jet port group is configured to gradually become smaller in diameter toward an upper portion with respect to the diameter on the roll kiss portion side. . 3. A twin-roll type continuous casting machine for continuously casting a thin slab by pouring molten steel between a pair of mold rolls and solidifying the molten steel, and is disposed in contact with the roll end surfaces of both mold rolls. The short side weir is formed of a main body having a gas reservoir chamber opened to the inner surface side, and an inner wall body closed to an opening of the gas reservoir chamber and attached to the main body. A large number of ejection ports are formed along the inner side of the roll outer peripheral edge of the mold roll, and the ejection pressure of gas ejected from these ejection ports is such that the roll kiss portion of the mold roll is higher and gradually lowers toward the upper portion. A short side weir for a twin roll type continuous sheet casting machine, comprising: 4. The gas reservoir is divided into a plurality of portions in the vertical direction from the molten metal surface to the roll kiss portion, and a gas pressure blown into each of the divided holes is increased as approaching the roll kiss portion. The short-side weir for a twin roll type continuous sheet casting machine according to claim 3, characterized in that: