JPS5832552A - Mold for continuous casting of thin walled ingot - Google Patents

Abstract

PURPOSE:To cast a thin walled ingot continuously while preventing thermal deformation by constituting the short side walls of a mold of downwardly convergent refractories buried internally with heating elements, providing quick cooling plates thereunder in continuation with said refractories and enclosing these with full frames. CONSTITUTION:Short side walls 11, 12 of an upwardly expanding and downwardly convergent shape of a mold are constituted of refractories 3 having an excellent heat insulating property, and heating elements 14 are buried therein via castables 15. Quick cooling plates 16 of a width equal to the width of an ingot are provided below the areas in contact with the molten metal to be charged into the mold, in continuation with said refractories. The plates 16 are made of water-cooling type metals having water flow passages 17 in the inside, and the upper parts thereof have an upwardly expanding and downwardly convergent shape equal to the shape of the refractory parts 13 so as to cover the rear surfaces of the parts 13. Thus the refractory parts 16 are strapped by the extension of the plates 16 and the walls 11, 12 of the mold 2' are held by enclosing the outer sides of the plates 16 further with full frames 18 of the same shape, whereby the thermal deformation of the mold is effectively prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an am for continuous casting of thin slabs,
In particular, we propose a type A suitable for continuous casting of ultra-thin slabs with a thickness of less than 30 K without going through ingot making or blooming.

Conventionally, to manufacture thin metal sheets, steel ingots are made by mass ingot processing, and then rolled to a thickness of 100 to 300 mm.
After making it into a rough slab, it is further rolled by a process called rough rolling for about 30...? The steel was heated to 1rK and then hot-striped into 4 steel plates with a thickness of 10 degrees or less. ,
.

On the other hand, 1. Conventionally, there has been a method as shown in Figure 1, in which thin-walled slabs are manufactured using a continuous casting method. This method involves injecting molten metal into a water-cooled mold via nozzle l,
Along the wall? After producing a shell 3, the solidified shell 3 is continuously drawn out through a guide pipe, and in order to also draw out a thin slab σ), a rough slab is drawn. Do it in the row 5 method. There were the following problems. In other words, in this method, the thickness of the piece is determined by the diameter of the nozzle, so the smaller the nozzle diameter, the better. Metal σ) In order to prevent solidification, it is necessary to set the magnitude K to be greater than K 100 f1, and generally /! I use one with a thickness of 0-/70. Therefore, the thickness of a piece that can be cast is /30 m at the bottom, and usually -〇θ~24
It has a thickness of 0 cm. In this sense, the mold used in the conventional continuous casting method described above has a substantially rectangular parallelepiped shape as shown in FIG. 1, which makes it difficult to pull out thin slabs.

On the other hand, in order to further improve the above-mentioned continuous casting mold, a mold with the following characteristics has been proposed in addition to continuous casting equipment as shown in FIG. This mold is made by arranging a pair of circulating belts, which are placed opposite each other in a jam-like shape, to form a molding space with a triangular cross section, which allows the flaky slab to be pulled out from the bottom. However, even this type of mold had the following drawbacks.

That is, in the case of the above-mentioned mold, even if it is possible to obtain a buried-shaped space III, the width f is small, and for example, K is small because hot water (more than 300 t/Hr) is supplied using an injection nozzle in hot weather. At least the inner diameter cross section rkr product (' ”
/2) 2x x sn' or more (within 4100 am or more), therefore a nozzle with an outer diameter of 130&l1 or more is required. 300 t/H using such a large capacity nozzle
A thin-walled cast slab that can supply water of 7 rlu and less than 100 yen? In order to continuously cast VC, it is necessary to apply a reduction (f-par) in the mold that is greater than the natural solidification, contraction and healing. In this regard, as shown in Figure 1 above, the continuous casting mold according to the conventional method is surrounded by a water-cooled mold to create a solid number, so it is impossible to narrow the mold beyond the amount of natural shrinkage due to solidification. . In short, in the case of a mold like rJ', the drawing line (the ratio of the difference between the upper and lower widths to the mold length) to create the lower filling shape is limited to 1allll of mail, 54, which is extremely thin. Difficult to manufacture pieces.

The present invention was developed with the aim of overcoming the drawbacks of the conventional molds mentioned above.

The mold makes it possible to use ultra-thin slabs of less than 10θ■ and <K30nK. The details of the configuration will be explained below.

The first figure of the drawings shows one embodiment of the method of the present invention, and is a perspective view of a continuous casting mold. First, a general explanation of this template will be given. 5. Injection nozzle/lower part of the entrance belt facing oppositely across the gap (fs construction space 6) for circulation: one piece width direction regulating fan circulation long side wall 5. − is placed. This circulation long side wall j, 6+1. Multiple side rolls 7.7', r/.

9.9', 10', 10' gives a constant distance 1llI
The cast metal is ejected while maintaining the gap for holding the cast metal across the IK, and the casting space formed by the circulating long side walls r and 4V is wide at the top and narrows downward.
It becomes a triangle. In response to such a reverse triangulation, [6 to 1 piece of 4]
The fixed short side walls ll', i which restrict the direction of rotation are installed on both side edges #c of the circulation long side walls j, 4, and these σ')
By surrounding it, the ultra-thin stalk piece A1aV as shown in the wLJ diagram
Thus, the mold core of the present invention which provides a casting space with C through is obtained.

In the continuous casting method using a mold according to the present invention, the molten metal injected into the above-mentioned casting space comes into contact with the casting wall, and the solidified shell is
When producing , the short side wall l/· in the thickness direction of the slab
This method produces a solidified shell 5 adjacent to /7.

When such casting is carried out, the solidified shell 3 produced within the mold (obtained by a combination of long and short walls) is mainly formed by long walls. Since it is limited to llI+, it is possible to increase the amount of constriction of the casting space (the ratio of the difference between the upper and lower widths to the length of the mold), and the so-called injection nozzle l
It is possible to directly draw extremely thin slabs of up to 30 mm without being restricted by the diameter of the slab. According to the embodiment, in the case of the present invention, - the short side wall that restricts the width of one short side //, the upper width a, the lower width S, the mold length t
It has been found that it is possible to apply a narrowing amount of about one degree (a-b)/nO6θ/S.

Based on the above findings; as a template of the present invention,
Regarding the short side walls l/, /-, which have a concave shape at the top and bottom, are made of refractory material /3 which has excellent thermal insulation properties, and a heating element /+gastaple /S is buried inside it. In addition, we propose a structure in which the lower VC, which corresponds to the casting space and is in contact with the injected molten metal, is connected to a quenching plate 76 having a width (b) equal to the thickness of the slab. The quenching plate l≦ is made of water-cooled metal (preferably copper) having a passageway /7 in its inner mass, and the upper part is connected to the refractory part /3 in order to cover the back surface of the refractory part 13. The upper width and lower width are equal to the shape of . The reason why the refractory part 13 is pressed against the extension of the quenching plate 1 in this way is to prevent the mold from becoming distorted due to thermal deformation.

In this regard, the short side walls // and / of the casting mold according to the present invention further effectively prevent thermal deformation by surrounding and holding the outer edge of the quenching plate 76 with a metal frame /1 having the same shape. The structure is as follows.

The short side wall constructed as described above in the mold of the present invention-'//
, /2, the solidification of the so-called short side of the slab progresses with a delay, so the drawing process becomes more flexible, and (a - o )
The amount of solidification shrinkage can be far exceeded.

Actual example: It is possible to use a nozzle with an outer diameter of about 730. The upper length of the short side wall is a = mow, m, and the lower length is b = 25.
1. BN (borononitride) with mold length of 700 mm
A mold was prepared in which the molten metal contact surface was made of a large-sized product and a 17-unit conductor was sealed inside. By passing a current through the conductor, the surface tlS of the refractory part decreases to 0゛c.
heated to. In addition, on the back side of the refractory part, a quenching plate with a predetermined thickness determined by taking into account slab #2 etc. is added to 5 as shown in Figure 1, and the quenching plate and the refractory part are further held. Added a #metal frame for this purpose. (a-b) of the above mold
)7. b% 0.336, the coagulation system number of the Futurosa genus is 30
It was possible to narrow down the ratio by more than double. The circulating long side II, which constitutes the long side of the slab, is made of rolls and thin metal steel plates, and the metal steel plate is used to draw the slab by the rolls.
The spray was cooled and transferred endlessly at a speed that was synchronized with the blowing speed.

Using such a template, "'0./, 2', 8110.
024Mn10.334, AI/ 0, 026% remaining l'i'e j t) fx 6791miλj■, I!
As a result of continuously preparing a 100 m thin steel plate, a slab with extremely good surface quality was exposed.

[Brief explanation of drawings]

Figure 1 of the drawings is a perspective view showing a conventional continuous casting mold;
Fig. 11 is a perspective view showing an example of the mold for continuous #1 production according to the present invention, Fig. 3 is a perspective view of the short side wall of the mold according to the present invention, and Fig. 3 is a vertical sectional view of the short side wall of the mold. l... Injection nozzle, 2. 2'... Mold, 3... Solidified cod, j, A... # Long wall of the castle, 7. za, 9, 10
...ga1 troll, //, /ko...short side wall, /
J... Refractory part, /q... Heating element, lS... Castable, /4... Quenching plate, 17... Water passage, /l
...Gold frame. Patent applicant: Kawasaki Steel Corporation 2

Claims (1)

[Claims] t A pair of circulating Naganuma walls arranged opposite each other to hold the cast metal over a certain distance, and a short side wall of the slab extending between the 70 long side walls. A pair of shorts! In the casting machine Wl, which forms a casting space with the wall, the short side wall has a narrow lower part that gradually tapers downward against a wide upper part in which a heating element is embedded. According to the world objects, 1. Below the refractory wall formed facing the casting space, 5 quenching plates each having a passageway with a width 4 times wider than the slab thickness are installed in series, and the extension and length of these quenching plates Cover the back of the above refractory wall,
In addition, the outside of the quenching plate is further surrounded and held by a metal frame, and this is used as a hoe for continuous casting of thin slabs! Type/