JPS5832551A - Method and mold for continuous casting of thin walled ingot - Google Patents

Abstract

PURPOSE:To cast an extra thin walled ingot continuously without undergoing the stage of rough rolling in continuous casting by casting said ingot in such a way that the heat radiation from short side walls is decreased and the solidified shell on both sides of the shoft sides of the ingot grow near the discharging port of the mold. CONSTITUTION:Short side walls 11, 12 of an upwardly expanding and downwardly convergent shape are formed of refractories having an excellent heat insulating property in retarding the solidification of the molten metal in contact therewith, and are provided continuously with quick cooling plates 13, 14 made of metals at the bottom ends thereof. The solidified shell of the parts in contact with the short side surface of an ingot grows in the places corresponding to the quick cooling plates in the end period of casting, whereby the thin walled ingot of a good shape is produced smoothly. Since the ingot is drawn continuously, the extra thin walled ingot having beautiful surface characteristics is produced without need for oscillation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous casting method and a casting mold for thin-walled cast slabs, and relates to a continuous casting method and a casting mold for thin-walled cast slabs, and includes ultra-thin slab ingots and blooming rolling processes of < K 100■ or less, especially up to 30■. We propose an advantageous manufacturing method.

Conventionally, to manufacture thin metal sheets, a steel ingot is made by one-mass ingot processing, and then it is bloomed and rolled to a thickness of /θ0 to 3θO.
After forming the slab into a 3 oz. u slab, it was further rolled into a 3 oz. 4 degree thin steel slab, which was then pot-striped into a 108 mm or less thin I4 slab.

In contrast, there has conventionally been a method shown in FIG. 1 in which thin-walled slabs are produced by continuous casting. This)-i method is
Inject the molten metal into the water-cooled mold through the nozzle and start casting! After generating the solidified shell 3 along the line 41, the solidified shell 3
This is a method in which a thick slab is continuously pulled out through a guide rail 1, etc., and then rough rolling is performed to form a thin slab.However, there are the following problems. In other words,
In this method, the thickness of the strip is determined by the diameter of the nozzle l, so the smaller the nozzle diameter is, the better. However, in order to prevent the molten metal from coagulating or solidifying inside the nozzle during injection, the nozzle diameter must be at least 100 ins, and generally the nozzle diameter is between /30 and /70 cm. using something. Therefore, the thickness of a piece that can be cast is /30M at the bottom, and usually -〇θ~260M.
It will be as thick as a parrot. In this sense, it is extremely difficult to directly manufacture thin-walled pieces using the conventional continuous casting method described above.

Therefore, in order to improve the drawbacks of the conventional continuous casting method mentioned above, especially the type 1, a pair of circulating belts as shown in Fig. A method has been proposed in which the above-mentioned bottleneck is solved by forming a triangular l1Al space. Although this method was able to cast slabs with a thin wall of 1η, its effectiveness was low, and it was difficult to cast slabs with a thickness of less than /θQ ms, which is the object of this invention. I am very good at IT. In this method, the narrowing ii' (ratio of the difference between the mold length Vc and the width of the upper and lower parts of the mold)
However, natural shrinkage due to solidification, shrinkage region (max /, 3%)
Since the upper limit is , the difference in the thickness direction of the slab is limited to several dragons, and the squeeze lid is 1. Since the width of the upper part of the cast piece is iso am, the width of the lower part is l da O, and the length is 1 ooo, it is considered as an object of non-invention.
It was difficult to manufacture the following extremely thin hook pieces.

The present invention solves the drawbacks of the above-mentioned continuous casting of thin-walled slabs, and directly produces ultra-thin slabs with a thickness of 30 degrees or more, without going through the rough rolling process. This paper proposes an advantageous manufacturing method using a continuous casting method along with a mold used in the method. The details of the configuration of the present invention 1 will be explained below.

The first figure in Figure 1 is an embodiment of the method of the present invention, and is an inkstone drawing of continuous casting equipment. First, to explain the outline of this equipment, a pair of circulating endless belts are placed below the injection nozzle l and facing each other with a predetermined gap (becomes a free space): namely, the circulation long side wall 5 for regulating the slab width direction. , 6 are arranged. This circulating long side wall 3.6 has a plurality of guide rolls 7.
, ri/, g, gl, 9.9′, 10′, 10′, while maintaining the gap for holding one bag over a certain distance 1lIl,
The casting space formed by 4IJt of the circulating long side walls S and l is an inverted triangle that is wide at the top and narrows downward. Fixed short side walls //, /co that regulate the thickness direction of a piece corresponding to such an inverted triangle are placed on both side edges of the long side walls S and 6 of the 1n ring, and by enclosing them, the shape shown in FIG. 3 is formed. A suitable casting hole 1 is used to produce such thin-walled cast slabs.

The % enemy of the method of the present invention is the above-mentioned casting void 1! The point of casting is that the gold pA molten metal injected with VC is poured into a furnace and the heat is removed so that the solidification growth progresses to @, #.

When such #ryu is carried out, the solidified shell 3 generated in the mold 2' (obtained by the combination of the tsubaki and the chibe wall) is
However, it is possible to increase the ratio of the difference in the width of the part and the lower part to the length of the casting space (mold 0). Ultra-thin slabs as thick as 30 mm can be drawn directly from the slab extraction side KN without having to reduce the diameter of the injection nozzle (K11+11) or being limited to 6 degrees of oscillation. According to the embodiment, in the case of the present invention, the short side of the hook piece is defined by 71111
The short side wall l/, /ko's 10 mli・-2a, the lower width,
The mold length is t, and the narrowing is ll(a-b)/z>
0.0/jmKf>f-harattf I found out that I can do kotoka.

In order to achieve the above-mentioned object of the method of the present invention, a mold consisting of a pair of circulating long side walls S, 6 and short sides @//, /ko is:
It has been found that the following structure is suitable.

, =4/[, the short side wall having a concave shape below the upper width //.

It was made of a refractory material with excellent heat insulation properties to delay the solidification of the molten metal in contact with it, thereby reducing the need for heat extraction molds and achieving the purpose. In this regard, with a conventional mold (as shown in Figure 1), the solidified shell 3 is generated along the inner surface of the mold, so there is a limit to forcibly narrowing it down, and generally -F part, lower part - difference (a-b
) is regulated by the solidification yield of the common money maple, and is usually about 7.54 or less per mold length t. In this point,
In the case of the mold of the present invention, there is no such restriction at all, and the so-called squeezing width can be made larger than /,j. This narrowing t/, 34 is the maximum value of the amount of shrinkage that can be expected during solidification, and is usually strict due to Vcd in the case of a nozzle diameter of 01g~/3 (/!; 0~/70m>). If the nozzle diameter is large in the axial direction due to mass production, as in the case of the conventional method, the aperture 1 will be even smaller.

In addition, the above-mentioned mold of the present invention has a short side wall made of the above-mentioned refractory material.
, /2' bottom - VRJ quenching plate /3, /4
It is a preferred embodiment to provide a continuous flow of 300 mm, which is convenient for solidifying the short sides of the slab by rapid cooling at the end of casting.

In addition, it has been found that the above-mentioned 111ii disease type of the present invention is also suitable for use as a 0#It structure which is further improved. In other words, as shown in the diagram, a structure in which heating can be achieved by embedding a heating element IS in a refractory with a short side of 12' is even more effective. . With such a mold structure, it is easy to cope with changes in the casting speed that occur in the lengthwise direction of the short side of the slab in ml, and is effective in achieving the infancy of the present invention without fail. In addition, /4t shown in the figure is a metal frame, and / is a lead wire.

Next, examples of the present invention will be described.

Example 1; Production of pieces for /4# plate KIIL, steel composition c: o, o
Dato MΩ: 0. Koro 4, st: o, ot 4. A
Using the equipment shown in Figure 2, the width of the circulation long side wall (#I single width) is set to iooowx,
Short-term memory % of molten steel pool: Horizontal BN (as the size of boron nitride refractory, upper part (a)
:2408, lower part 1bl: 30 pieces were used. Therefore, the d4 space has an upper part of 240 X/θθθ angle and a lower part of 3
It corresponds to the narrowing down of θX 1000-. In this 'J example, the vertical solid shell f'1, which corresponds to the short side of the slab, is generated in the quenching plate phase, and therefore has a good shape of 3θX1.
We were able to manufacture thin pieces for 00θ fighting without any problems. The casting speed at this time (the circulating long side wall transfer speed by the guide roll lj9) was 4"/in, and since the drawing was continuous, there was no need for oscillation (σ), and an ultra-thin piece with a beautiful surface texture was produced. Manufactured.

Example 2; Upper part a: 260 degrees as the short side wall composing the piece shape.

Lower gb:, yθm, height t: 7oo am BN
I used IILV refractory J"k. The squib is equivalent to 0.33.

A water-cooled steel quenching plate with a width of 30 square meters and a length of 500 square meters was installed below the short side wall. Using equipment with short walls like this, C: 0.03g Excellent, Mn: θ, 3/41.8i
: 0-024, At: 0.0324 steel, and despite the large amount of drawing, an extremely thin slab could be manufactured without any side problems.

Example 5: Using the same equipment as shown in Example 2, a similar short wall was constructed by embedding a heating element of Nirikonitsu in BN 1llj refractory W, and flowing the current through the lead wire. 153 on the short side wall before starting casting! When the - of Example 2 was heated to -C and cast at 6 m/min, a thin piece of dJR with good surface quality could be produced in order JK#.

As explained above, according to the present invention, it is possible to
By the casting described above, an ultra-thin slab could be manufactured at low cost and with a high raw material σ without going through the process of phase rolling.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a mold of a conventional continuous casting equipment, and FIG. 1 is a sectional view showing an example of the short side wall of the mold of the present invention. C... Injection nozzle, 2.2'... Mold, 3... Condensation 1
Shika, Yu, 6... Circulating long side wall, 7, g, 9
, 10... Guide roll, ii, /Cor V side wall,
/3..., @! , 1v0 patent sponsor Kawasaki Steel Corporation

Claims (1)

[Scope of Claims] 1. A pair of oppositely disposed long side walls for regulating the width direction, which circulate while maintaining a predetermined gap, and a short side wall for regulating the storage direction disposed between the long side walls. In the continuous casting method, in which molten metal is injected from one side into a casting space surrounded by side walls and solidified slabs are pulled out from the other side, the casting space is A continuous casting method for thin-walled pieces, characterized in that a solidified shell on one short side is formed near the mold outlet. 2. A pair of opposing circulating long side walls that circulate while maintaining a gap for holding the cast metal over a certain distance;
70 In a casting IJ in which a casting space is formed by a pair of short side walls for controlling the cleaning of the short side of the cast strip extending between the long side walls, the short side walls are tapered downward tK sequentially with respect to the wide upper part. Casting type #S for continuous casting of thin-walled slabs, characterized in that it is formed by a refractory material provided at a narrower lower part. 5. Constant distance 11! A pair of circulation long side walls arranged opposite each other to circulate while maintaining a gap for holding the cast gold mt, and a pair of short side walls for regulating the short side of the clam cast strip extending between the long side walls. In the hook shape that forms the casting space, the upper short side wall is made of refractory material with a narrow lower part that tapers downward to the wide upper part, and a heating element is buried inside it. A casting mold for continuous casting of thin-walled slabs.