JPH06198397A - Method and device of continuous casting of thin thickness dual layer sheet - Google Patents

Abstract

PURPOSE:To easily produce a high quality dual layer sheet without modifying an existing twin roll caster by dipping a parting plate at the center of a molten metal pool, charging a different molten metal on each roll surface and rolling to clad the shell solidified/formed at the kissing point of a roll. CONSTITUTION:At the approximate center part of a molten metal pool, which is formed by facing cooling rolls 1a, 1b and side weirs, molten metal pool parts 4a, 4b are formed by dividing the molten metal pool into two in the direction of roll axis by dipping a parting plate. The different kinds of molten steels are supplied from tundishes 2a, 2b placed above each molten metal pool 4a, 4b, forming solidified shells 8a, 8b on each roll, a thin dual sheet of one body is obtained by rolling to clad force at the kissing point 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for casting a multi-layer thin plate in a twin-drum casting apparatus for producing thin metal slabs.

[0002]

2. Description of the Related Art Recently, a method for directly cold-rolling a slab by omitting the hot rolling process by producing a thin slab of metal by, for example, a twin drum continuous casting method has been developed and put into practical use. ing. Since the slab is rapidly solidified by this method, it is expected that the quality will be considerably improved. In the field of sheet materials, development of multi-layer steel sheets with different material properties on the front and back sides is also active. The conventional multi-layered steel sheet is mainly produced by stacking different steel sheets and welding the peripheral edges thereof, followed by explosion welding or hot rolling. However, in this method, the production and the cost were actually applied to those with many restrictions and limited production on a commercial basis. From this point of view, the technique of applying the thin cast slab continuous casting method to the production of multi-layer steel sheet has been studied and reported so far, but none has yet reached an actual machine.

Regarding a method for producing a multi-layer thin plate by a twin-drum type casting method, for example, Japanese Unexamined Patent Publication No. 4-52052 discloses a slab cast by an upper drum by arranging a pair of drums in two upper and lower stages. A method and apparatus for producing a three-layer clad plate by casting between a solidified shell of a slab cast by a lower drum is disclosed. However, in this method, it is difficult to match the speeds of the upper drum and the lower drum, and it is difficult to center the slab coming out of the upper drum, so that shearing force acts on the interface and the pressure bonding at the interface becomes insufficient. On the other hand, Japanese Patent Application Laid-Open No. 4-138845 discloses a method in which different kinds of molten metal (aluminum) are jetted onto the surfaces of a pair of drums, and the solidified shell is crimped by the drums. This method has a problem that an oxide is mixed at the interface between both materials, and there is a problem in the characteristics as a multilayer steel sheet, and improvement has been desired.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional method. In the twin-drum casting method, an existing casting machine is used to manufacture thin plate clads having different front and back surfaces. The purpose is to simplify and improve the quality. That is, molten steel of different steel types is simultaneously rapidly solidified and pressure-bonded at the kissing point of the drum, and its thickness can be freely adjusted during casting by controlling the rotation speed of the drum and the height of the pool and the interval between the drums. Provided are a continuous casting method for layered thin plates and an apparatus therefor.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the gist thereof is to provide a twin-drum type continuous casting machine for thin-walled metal slabs with a pair of cooling drums and a pair of cooling drums facing each other. A partition plate that divides the pool of water into two spaces in the drum axial direction is provided in the vicinity of the center of the pool of water formed by the side weir, and molten steel of a different type is injected into each of the divided two spaces. A continuous thin-walled thin plate characterized by forming a solidified shell on each cooling drum surface by pressing each other at the drum kissing point to form a multi-layered slab with different materials on the front and back sides. It is a casting method.

Further, in a twin-drum type continuous casting machine for thin-walled metal slabs, the molten metal pool is formed near the center of the molten metal pool formed by a pair of opposing cooling drums and a pair of side dams. A continuous casting device for thin-walled multi-layer thin plates, characterized in that a partition plate that divides into two spaces is provided in the hot water pool portion, the lower end portion of the partition plate being 50 mm or more and 100 mm or less above the drum kissing point. The partition plate side end is separated from the side weir by 3 mm or more, and the partition plate is a continuous casting device for a thin multi-layer thin plate made of a refractory material having a thickness of 10 mm or more.

[0007]

That is, in the present invention, a partition plate made of refractory is immersed in the center of the molten metal pool, and different kinds of molten steel are poured into each drum surface. Can be manufactured. Further, surface oxidation at the interface between both materials of the multi-layer and inclusion of inclusions and bubbles are small, and the quality is improved.

As a method for producing a thin multi-layer thin plate of the present invention,
As the combination of front and back metals, for example, a combination of high carbon steel and low carbon steel, a combination of alloy steel and ordinary steel, and a combination of some non-ferrous metals and iron alloys are possible. Further, when a combination of metals having extremely different solidification temperatures and viscosities is used, it is necessary to change the setting to more appropriate conditions when carrying out the method of the present invention. However, basically any combination can be implemented.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention. As shown in FIG. 1, substantially at the center of the molten metal pool formed by the cooling drums 1a, 1b and the side dams 6 facing each other,
The partition plate 3 is dipped to divide the molten metal pool portion into two in the axial direction of the drum to form the molten metal pool portions 4a and 4b. Tundishes 2a, 2 arranged above the respective pools 4a, 4b
The molten steel is supplied from b, and the cast slab 5 of a thin multi-layer thin plate is obtained. The slab has a thickness of 2 to 5 mm, and is made of a combination of steels having different materials on the front and back surfaces as described above.

Further, the tundish 2a, 2b has a capacity of about 5t and is independently provided according to the number of layers (two layers in this embodiment), and the tundish nozzles 7a, 7b are provided for each tundish 2.
At least one is attached to a and 2b. In this embodiment, the width (upper surface position) of the upper part of the pool 4a, 4b is about 30 to 50 cm, the width on one side is 15 to 25 cm, and the length is 120 cm. The immersion depth of the partition plate is the pool. It is 30 to 40 cm from the upper part of the part. FIG. 2 is A-A of FIG.
FIG. 3 is a cross-sectional view showing an enlarged view of the pool of water.
The distance Y between the lower end of the partition plate 3 and the kissing point 9 which is the closest point of the cooling drums 1a and 1b is 50 mm or more, 100
It is necessary to provide a space below the partition plate to form a space at the lower end position of the partition plate, and a space of 5 mm or more between the lower end edge of the partition plate and the drum surface.

When the distance Y is 100 mm or less, the dissimilar molten steel is not mixed, and when the distance Y is 50 mm or more, the pressure bonding of the solidified shells 8a and 8b at the kissing point 9 is not hindered. The side end position of the partition plate 3 is separated from the side weir 6 by 3 mm or more. This is because when the thickness is less than 3 mm, the molten steel surface is solidified and solidified deposits are generated on the surface of the side dam 6. The partition plate 3 is made of a refractory material and is made of, for example, a material such as boron nitride, and its thickness is preferably 10 mm or more in order to secure the corrosion resistance and the damage resistance.

Under the above conditions, the molten steels 4a and 4b of different steel types divided into two by the partition plate 3 form solidified shells 8a and 8b on the respective drum surfaces, and are integrated by the crimping force of the drum at the kissing point 9. It is crimped to a thin multi-layer thin plate. The thickness of the thin multi-layer thin plate can be controlled by adjusting the casting speed, the molten metal surface level of the molten metal pool, and the distance between the drums during the pressure bonding. The crimping force of the drum is 0.2 t / cm ² , and since the crimping is performed in a clean state with no inclusions or bubbles entrapped on the crimping surface, this crimping force is sufficient for thin-walled multi-layer thin plates of different steel types. Can be manufactured. Further, when manufacturing a thin multi-layer thin plate having different wall thicknesses among different steel types, the position of the partition plate 3 may be moved in the plate thickness direction. In this case, it is desirable to make the cooling ability different between the cooling drums 1a and 1b, reduce the cooling ability of the cooling drum on the thin side, and reduce the thickness of the solidified shell.

[0013]

As described above, the present invention makes use of the advantages of rapid solidification casting to enable continuous casting of thin multi-layer thin plates which are clad without modifying existing twin-drum type casting equipment. In addition, since the plate thickness of the slab can be changed during casting by changing the drum interval, casting speed, and molten metal level, continuous operation can be performed stably and the surface at the interface between both materials can be changed. Oxidation, inclusions and bubbles are less entrained, and the quality is significantly improved over the conventional method.

[Brief description of drawings]

FIG. 1 is a schematic view of a twin-drum type continuous casting method according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG. 1 of the embodiment of the present invention.

[Explanation of symbols]

 1a, 1b ... Cooling drum 2a, 2b ... Tundish 3 ... Partition plate 4a, 4b ... Divided basin pool 5 ... Thin multi-layered thin plate 6 ... Side weir 7a, 7b ... Tundish nozzle 8a, 8b ... Solidification shell 9 ... Kissing point

Claims (4)

[Claims] 1. A twin-drum continuous casting machine for casting thin-walled metal slabs, wherein the molten metal pool portion is formed near the center of the molten metal pool portion formed by a pair of opposing cooling drums and a pair of side dams. A partition plate that divides into two spaces is provided,
By injecting different kinds of molten steel into the divided two spaces, and by pressing the shells formed by solidifying the molten steel on each cooling drum surface to each other at the drum kissing point,
A continuous casting method for a thin multi-layer thin plate, characterized by forming a multi-layer slab having different materials on both sides. 2. A twin-drum continuous casting machine for casting thin-walled metal slabs, wherein the basin is formed in the axial direction of the drum near the center of the basin formed by a pair of opposing cooling drums and a pair of side dams. A continuous casting device for a thin multi-layered thin plate, characterized in that a partition plate that divides into two spaces is provided in the hot water pool. 3. The thin multi-layer thin plate according to claim 2, wherein the lower end of the partition plate is spaced from the drum kissing point by 50 mm or more and 100 mm or less, and the partition plate side end is spaced from the side dam by 3 mm or more. Continuous casting equipment. 4. The continuous casting apparatus for thin multi-layer thin plates according to claim 2, wherein the partition plate is made of a refractory material having a thickness of 10 mm or more.