JP3340344B2 - Manufacturing method of short side weir in twin roll continuous casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a short side weir in a twin roll type continuous casting facility.

[0002]

2. Description of the Related Art When a thin plate having a thickness of about 3 mm is manufactured by continuous casting, a twin-roll type continuous casting facility is used.

In this twin-roll type continuous casting production, a pair of mold rolls arranged in parallel with each other are provided.
A mold is constituted by short side weirs arranged at positions corresponding to both ends of both mold rolls.

Conventionally, Tanhenseki constituting the mold, zircon refractories alone of (ZrSiO _4), or at a location in contact with the end surface of the mold roll, excellent wear resistance silicon nitride (Si ₃ N _An embedded ceramic piece consisting of ₄ ) was used.

[0005]

However, according to the above-mentioned zircon refractory simple substance, there is a problem that molten steel is stuck to the surface thereof and wear at a contact portion with an end face of a mold roll is remarkable.

When a ceramic piece is embedded in the surface of a short side weir, the place where the ceramic piece is embedded, that is, the groove, has a complicated shape, and this groove requires high-precision processing, so that the manufacturing cost is very high. There was a problem of being expensive.

Accordingly, an object of the present invention is to provide a short-side weir that can prevent abrasion at a portion where molten steel is stuck and in contact with an end face of a mold roll and can suppress an increase in manufacturing cost. I do.

[0008]

In order to solve the above-mentioned problems, a method of manufacturing a short side weir in a twin roll type continuous casting facility according to the present invention comprises a pair of mold rolls arranged in parallel with each other, and a pair of these mold rolls. A method of manufacturing a short side weir in a continuous casting facility in which a mold is formed by a short side weir formed of refractory and arranged at locations corresponding to both ends of a mold roll, first contacting end faces of both mold rolls The wear part to be made and the molten steel part that contacts the molten steel are each manufactured by a ceramic piece, and then these ceramic pieces are arranged in a mold for manufacturing a short side weir,
Next, a refractory is poured from above to produce a short side weir.

According to another aspect of the present invention, there is provided a method of manufacturing a short side weir in a twin roll type continuous casting facility, wherein a wear resistant material is used as a material of a ceramic piece disposed in a wear portion. In addition, this is a manufacturing method using a material having resistance to molten steel adhesion as a material of ceramic pieces arranged in the molten steel portion.

[0010] In another method of manufacturing a short side weir in a twin roll type continuous casting facility according to the present invention, in each of the above manufacturing methods, the ceramic piece disposed at the wear portion may be
This is a manufacturing method in which any one of ZrO ₂ , Al ₂ O ₃ and Si ₃ N ₄ is used, and ZrO ₂ is used as a ceramic piece disposed in a molten steel portion.

Further, according to another method of manufacturing a short side weir in a twin roll type continuous casting facility of the present invention, in each of the above manufacturing methods, the thickness of a ceramic piece disposed at a worn portion is set to 1 mm or more, and This is a manufacturing method in which the thickness of the ceramic piece arranged in the portion is set to 5 mm or less.

According to each of the above-mentioned methods of manufacturing the short side weir, a ceramic piece manufactured in advance is placed in a mold on a wear portion in contact with an end face of a mold roll and a molten steel portion in contact with molten steel. Since the short side weir is manufactured by pouring the refractory material, a troublesome work is not required as compared with a case where a groove is formed in a wear-resistant portion and a ceramic piece is fitted into the groove.

Further, as a ceramic piece of a wear portion,
Wear resistant ZrO_Two , Al_Two O _Three , Si_Three N_Four No
Use a piece of ceramic and a piece of ceramic in the molten steel
As ZrO_Two Uses a long life
Can be achieved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a short side weir according to an embodiment of the present invention will be described with reference to FIGS.

First, the schematic configuration of the short side weir in the present embodiment will be described. This short side weir is used in a twin roll type continuous casting facility, and as shown in FIG.
The short side weir 1 is arranged so as to come into contact with the end faces of a pair of mold rolls 2 and 2 arranged in parallel with each other. The pair of mold rolls 2 and 2 and the pair of short side dams 1 constitute a mold.

As shown in FIGS. 2 and 3, the short side weir 1 is formed to have a predetermined thickness and an inverted triangular shape when viewed from the front, and has an end face (surface) on the mold roll 2 side.
Are worn portions (wear zones, which are indicated by oblique lines, which are in contact with the arc-shaped mold rolls 2 corresponding to the rotation trajectories of the edge end surfaces of the respective mold rolls 2; two types of directions opposite to each other). The hatched portion indicates an actual contact portion with the end face of the mold roll.) 4 and a molten steel portion (contact zone) that comes into contact with molten steel corresponding to the molten steel reservoir 3 above the worn portion 4.
And five.

A wear-resistant ceramic piece 6 is used for the wear portion 4 of the short side weir 1, and a ceramic piece 7 having adhesion to the molten steel is used for the remaining molten steel portion 5. You.

More specifically, any one of ZrO ₂ , Al ₂ O ₃ and Si ₃ N ₄ is used as a material of the ceramic piece 6 arranged in the wear portion 4, and the ceramic piece 6 is arranged in the molten steel portion 5. As the material of the ceramic piece 7,
ZrO ₂ is used.

When the short side weir 1 is manufactured, first, a ceramic piece 6 corresponding to the shape of the wear portion 4 which comes into contact with the end faces of the two mold rolls 2 and a ceramic piece 7 corresponding to the shape of the molten steel portion 5 are formed by: Each is manufactured from the above-mentioned materials (ceramic materials).

That is, these ceramic pieces 6, 7
First, after the metal mold is formed with a pressing force of 150 kg / cm ² , cold isostatic pressing is performed at a pressure of 2000 kg / cm ² (C
(IP molding), and baked under normal pressure.

Next, the ceramic pieces 6, 7 thus obtained are placed on the bottom of the mold 11 shown in FIG.
A zircon (ZrSiO ₄ ) refractory 8 was poured at a predetermined height from the top, molded integrally with each other, and further dried at 200 ° C. for 20 hours.

Here, the results of an experiment conducted to select the above-mentioned materials as the materials of the ceramic pieces 6 and 7 will be described. In this experiment, first, the ceramic material and thickness were variously changed to obtain a predetermined size (50 mm × 5 mm).
0 mm), and a test piece relating to a short side weir in which a refractory was integrally formed with the ceramic piece using a mold was actually immersed in molten steel.

Note that the ceramic piece was first weighed 150 kg /
After molding with a pressure of ² cm2, 2000 kg
/ Cm ² , which is obtained by cold isostatic pressing (CIP molding) and then sintering under normal pressure. The ceramic piece thus obtained is placed on the bottom of the mold. A zircon refractory was poured from above, molded integrally with each other, and dried at 200 ° C. for 20 hours to obtain a test piece.

The size of this test piece is, for example, 50 mm × 5
The size was 0 mm x 100 mm (height), and two of each were manufactured. Next, one of the two test pieces was made 1
10 ° C in 500 ° C stainless steel (SUS304)
The immersion was carried out for a minute (the immersion depth was 75 mm), and the adhered state of the molten steel on the surface portion of the ceramic piece and the presence or absence of cracks were examined.

The remaining one test piece was used for a wear resistance test. In addition, the test method, on the end face of the mold roll of the twin mold thin sheet continuous casting machine,
It was pressed with a pressing force of 100 kg / cm ² for 10 minutes, and its abrasion state was examined. The absence of the ceramic layer was used as a criterion for quality.

The results are shown in Table 1 below.

[0027]

[Table 1]

As can be seen from Table 1, as a result of the immersion test, no sticking of molten steel was found on the ZrO ₂ ceramics (Document Nos. 1, 2, 3, 4). But,
When the thickness of the ceramic piece to be embedded was increased, cracks occurred (Document No. 4).

Therefore, it has been found that a ZrO ₂ ceramic material is good for the molten steel portion. However, from the viewpoint of cracking, a thickness of 5 mm or less is suitable. Note that ceramics of Al ₂ O ₃ quality and Si ₃ N ₄ quality are not suitable.

Further, as a result of the abrasion resistance test, ZrO ₂ quality,
Although the Al ₂ O ₃ quality and the Si ₃ N ₄ quality are good, if the thickness of the ceramic piece is small, the portion of the ceramic layer immediately appears due to abrasion, which is not suitable for use. Therefore, a thickness of 1 mm or more is suitable.

From the above results, the molten steel portion is made of ZrO ₂ material with no sticking of molten steel, and the wear portion in contact with the mold roll is made of ZrO ₂ material having wear resistance, Al ₂ O _3.
Quality, Si ₃ N ₄ quality.

The shape of the ceramic piece was adjusted to a size suitable for the actual machine, and the same procedure as that for the above-described test piece (after performing die molding with a pressing force of 150 kg / cm ² , and then 2,000 kg / cm ² ). Cold isostatic pressing at a pressure of ² cm2
Then, it was fired under normal pressure). This ceramic piece was placed in a mold, and a zircon refractory was poured from above onto the mold to make a thickness of 30 mm.
The material dried at 20 ° C. for 20 hours was applied to an actual machine.

Of course, the surface of this short side weir has a worn portion,
Although it is roughly divided into a molten steel part, each of these parts was evaluated. The results are shown in [Table 2] below. In this evaluation, a molten stainless steel (equivalent to SUS304) was used as a cast molten steel in an actual machine at 1500.
It is the one when casting at ℃.

[0034]

[Table 2]

In Table 2, data numbers 1 and 2 were obtained when ZrO ₂ (zirconium) was used for both the wear portion and the molten steel portion, and the evaluation was good. Further, with respect to the material No. 3, the wear portion was Al ₂ O ₃ ,
When the molten steel portion is ZrO ₂ is better in overall evaluation, and for the article number 4, the wear part is Si ₃ N
_{4. Even} when the molten steel portion was ZrO ₂ , the overall evaluation was also good.

Material No. 5 is a prior art, and an experiment was conducted for comparison. That is, when the entire short-side weir was made of a single refractory, that is, when both the wear portion and the molten steel portion were made of ZrSiO ₄ (zircon), both the wear resistance and the adhesion of the molten steel were poor.

As described above, after the ceramic piece formed in a predetermined shape is arranged in the mold, a refractory is poured from above the ceramic piece to manufacture the short side weir. The operation of accurately forming the groove in the portion and fitting the ceramic piece into the groove becomes unnecessary, and therefore, the manufacturing operation thereof becomes very easy.

The wear portion is made of ZrO having wear resistance.
₂ , a ceramic piece made of any material of Al ₂ O ₃ or Si ₃ N ₄ is used, and a molten steel portion is made of ZrO.
By using a ceramic piece made of ₂ (zirconium), it is possible to extend the life of the entire short side weir.

By the way, in the above embodiment, the ceramic piece embedded in the short side weir was described as being integrally molded.
It may be manufactured by pouring a zircon refractory in a mosaic shape in a mold.

Also in this case, as in the above-described embodiment, troublesome work such as conventional groove machining and fitting work can be omitted, so that the short side weir can be easily manufactured.

[0041]

As described above, according to the method of manufacturing a short side weir of the present invention, a ceramic piece prepared beforehand is placed in a formwork on a wear portion in contact with an end face of a mold roll and a molten steel portion in contact with molten steel. After placement, refractory was poured from above and the short side weir was manufactured, so a troublesome work such as forming a groove in the wear resistant part and fitting a ceramic piece into this groove as in the past was done Is not required, and the manufacturing cost can be reduced.

As a ceramic piece of the molten steel portion,
Wear resistant ZrO_Two , Al_Two O _Three , Si_Three N_Four No
Use a piece of ceramic and a piece of ceramic in the molten steel
As ZrO_Two Uses a long life
Can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a continuous casting facility according to an embodiment of the present invention.

FIG. 2 is a front view of a short side weir in the embodiment.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a cross-sectional view for explaining a manufacturing procedure of manufacturing in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Short side weir 2 Mold roll 3 Molten steel pool 4 Wear part 5 Molten steel part 6 Abrasion resistant ceramic piece 7 Molten steel adhesion ceramic piece 8 Refractory 11 Formwork

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-207554 (JP, A) JP-A-62-166054 (JP, A) JP-A-7-68353 (JP, A) 85152 (JP, U) Japanese Utility Model 63-94848 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B22D 11/06 330

Claims (4)

(57) [Claims] 1. A continuous mold comprising a pair of mold rolls arranged in parallel with each other, and short side dams formed of refractory and arranged at locations corresponding to both ends of these mold rolls. A method of manufacturing a short side weir in a casting facility, in which first, a wear portion that comes into contact with the end faces of both mold rolls and a molten steel portion that comes into contact with molten steel are made of ceramic pieces, respectively, and then these ceramic pieces are formed on the short side. A method for manufacturing a short-side weir in a twin-roll continuous casting facility, wherein the short-side weir is manufactured by disposing in a mold for manufacturing a weir, and then pouring a refractory from above. 2. A method of using a wear-resistant ceramic piece as a material of a ceramic piece disposed on a wear portion, and using a material of a molten steel adhesion-resistant material as a ceramic piece disposed on a molten steel portion. The method for producing a short side weir in a twin roll continuous casting facility according to claim 1. 3. A ceramic piece disposed on the wear portion is any one of ZrO ₂ , Al ₂ O ₃ and Si ₃ N ₄ , and ZrO ₂ is used as a ceramic piece disposed on the molten steel portion. The method for producing a short side weir in a twin roll continuous casting facility according to claim 1 or 2, wherein: 4. The method according to claim 1, wherein the thickness of the ceramic piece disposed in the wear portion is 1 mm or more, and the thickness of the ceramic piece disposed in the molten steel portion is 5 mm or less. A method for producing a short side weir in a twin roll continuous casting facility according to any one of the above.