JPH03169458A - Apparatus for continuously casting composite steel material - Google Patents

Abstract

PURPOSE:To continuously cast a cast strip having clear boundary by arranging a separating means for parting pouring basin part in the pouring basin part and pouring different molten metal into each pouring basin part parted with the separating means. CONSTITUTION:The continuous casting apparatus cast the strip (composite steel material) 11 composed of different metal layers by growing the solidified shell 11b of molten metal 9b, which has the solidified shell developing start point at the position just below the separating means 7, on the solidified shell 11a of molten metal 9a, which grows as the solidified shell developing start point at the contacting point of a fixed weir 6 and belt 1. Therefore, as the solidified timings of different metals 9a, 9b are not matched, the strip 11 having clear metal boundary can be continuously cast.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for continuously casting a metal slab (composite steel material) made of a plurality of layers having different chemical contents.

[Conventional technology]

Conventionally, methods for manufacturing composite steel materials that integrate metal plates with different chemical precepts include hot rolling of multiple metal plates with rolls (rolling method), explosion bonding method of integrating metal plates using explosive pressure, and melting. The casting method involves inserting another solidified metal plate into the metal and solidifying the molten metal to create a composite material. Two immersion nozzles of different lengths are inserted into the molten metal pool in the mold.
There is a vertical casting method, etc., in which the discharge holes of the respective nozzles are provided at different positions in the casting direction and various molten metals are injected (see Japanese Patent Publication No. 44-27361).

[Problem to be solved by the invention]

The rolling method and the explosion bonding method described above require heating equipment, rolling equipment, or a casing to seal the metal plates together, so both tend to increase production costs. The size is also limited and productivity is low.

Furthermore, in the casting method, oxides are likely to form at the boundary between the immersed metal plate and the molten metal, and defects are likely to occur on the joint surfaces. Therefore, from the viewpoint of improving productivity and preventing defects on joint surfaces, the above-mentioned vertical casting method, in which metal slabs (composite steel materials) are continuously manufactured from liquid metal, is currently most suitable. However, in this method, different metals solidify at approximately the same time, so as the injection of molten metal progresses, the different metals mix, and the concentration becomes uniform in the thickness direction from the surface layer to the inside of the produced slab. In addition, the molten metal is distributed so that the outer layer surrounds the inner layer, and the thickness of the multiple layers becomes symmetrical in the thickness direction of the slab. However, there is a problem in that it is not possible to obtain a composite steel material with an asymmetrical structure, such as a two-layer steel plate.

The object of the present invention is to provide a casting device that solves the above-mentioned problems.

[Means to solve the problem]

For the above purpose, according to the present invention, a continuous casting device continuously casts a metal ribbon by cooling and solidifying molten metal poured into a pool provided on a belt running at an angle. The method is characterized in that the molten metal is provided with an isolating member in the molten metal sump that divides the molten metal sump in the casting direction, and a different molten metal is poured into each molten metal that is partitioned by the molten metal sump. Provided is a continuous casting apparatus for composite steel materials.

[For production]

By forming each sump section separated in the casting direction by means of isolation means, the molten metal poured into the lowest corresponding sump section on the belt first solidifies, and then flows into the adjacent sump section. Since the molten metal poured into the area solidifies, the solidification times of different metals do not coincide, making it possible to continuously cast slabs with clear boundaries and reducing the number of separating hands. Since there are no restrictions on the number of tundish parts, it is also possible to cast a certain composite steel material from three or more types of layers that are not necessarily vertically symmetrical, depending on the number of pool parts to be formed.

〔Example〕

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

FIG. 3 shows a schematic structure of a continuous casting apparatus according to the present invention.

In this casting device, a metal belt 1 is connected to a pair of poo! It spans J2a and J2b and runs on an endless track. By holding the other pulley 2a higher than or at the same height as the pulley J2b, the belt 1 becomes inclined or horizontal, and its endless track follows the casting direction indicated by the arrow A. It will move upward or horizontally toward the surface. This belt 1
A plurality of heat-resistant blocks 3 connected by chains or the like are arranged on both sides of the belt 1, and these heat-resistant blocks 3 move in synchronization with the running of the belt 1.

The heat-resistant block 3 serves as a side weir 5 that partitions the side of the sump 4 at the upper portion where the belt 1 runs linearly. On the other hand, at the rearmost part of the water reservoir 4, a fixed weir 6 that slides into contact with the running bell 1 is fixed by a support mechanism (not shown). As a result, a pool 4 is formed which is open only in the direction in which the belt 1 moves.

In the casting direction A, the tundish sump 4 has a
Isolation means 7 are provided which divide the water into sump portions 4a and 4b. This isolation means 7, like the fixed weir 6 mentioned above,
For example, it may be a solid float formed from a refractory material such as ceramic and suspended in the molten metal in the vicinity of the solidified shell lla that will be produced later, or it may be a solid float that is disposed opposite to each other with the belt 1 in between and perpendicular to the casting direction A. A static magnetic field is formed by generating lines of magnetic force in the separation means 7, and the flow of metal poured into the pool portion 4b located eight downstream in the casting direction from the separating means 7 is caused to flow toward the upstream side in the casting direction, that is, the mixing of different metals. An electromagnetic brake may also be used to stop this. Alternatively, an electromagnetic brake may be used that generates lines of magnetic force from the outside of the side weirs 5 on both sides in the width direction of the slab (in the direction perpendicular to the plane of the paper in FIG. 1).

Molten metals 9a and 9b having different chemistries are respectively poured into the pool portions 4a and 4b separated by the isolation means 7 from the respective pouring devices 8a and 8b. The poured molten metals 9a and 9b are then heat removed by a cooling device IO disposed on the back surface of the belt 1, cooled and solidified, and become solidified shells lla's and llb, respectively. The solidified shells lla and llb are transported rightward in the figure as the belt 1 moves. Since heat continues to be removed during this conveyance process, the solidified shell 11a. 1
lb is lengthened into a thin ribbon l1 having a predetermined thickness, and sent out from the sump portion 4b.

The thin ribbon 1l is finally wound up as a thin plate coil 13 by a winding device 12. Alternatively, it is cut into a predetermined length by a cutting device (not shown) and taken out as a cut plate.

FIG. 2 is an enlarged view of the vicinity of the sump 4 where the isolation means (for example, a solid float) 7 is located in FIG. 1.

As shown in the figure, the continuous casting apparatus according to the present invention has a fixed weir 6
The separator hand 7 is placed on the solidified shell 11a of the molten metal 9a extending from the point of contact with the belt 1 as the solidified shell formation or starting point.
A certain ribbon (composite steel material) 11 is cast from different metal layers by lengthening the solidified shell 1lb of the molten metal 9b with the solidified shell forming or starting point being approximately directly below the molten metal layer. Since the solidification times of the metals 9a and 9b do not coincide, it becomes possible to continuously cast the ribbon 11 with clear boundaries between the metal layers. Further, in this casting method, since two solidified shells are joined in a liquid, an oxide film is less likely to be formed at the boundary thereof, and therefore a composite steel material with few interface defects can be provided.

Note that in the embodiment described above, the pool is divided into two in the casting direction by one separating means, and a composite steel material consisting of two layers is cast, but the number of separating means is limited to this. It is also possible to increase the number of pools as required and to cast a multilayer composite steel material from a plurality of divided tundish parts.

〔Effect of the invention〕

As explained above, according to the present invention, in order to solidify different molten metals from pool portions whose positions are different in the casting direction, it is possible to cast a composite steel material with clear boundaries due to mismatched solidification times, and By joining different layers in liquid, it is possible to provide a composite steel material with fewer defects at the interface. In addition, by changing the number of isolation means, the number of partitioned sump sections can be changed, and thus a composite steel material can be made from any number of different metals.

[Brief explanation of the drawing]

Fig. 1 is a schematic structural diagram of a continuous casting apparatus according to the present invention;
The figure is a partially enlarged view of FIG. 1... Belt, 4... Hot water reservoir, 4a
・4b... Hot water pool part, 7... Isolation means, 9a, 9
b... Molten metal, 11... Ribbon (composite steel material), ] Fig. 2

Claims (1)

[Claims] 1. A continuous casting device that continuously casts a metal ribbon by cooling and solidifying molten metal poured into a sump provided on a belt that runs at an angle. A composite steel material, characterized in that an isolation means for dividing the molten metal pool in the casting direction is provided in the molten metal sump, and a different molten metal is poured into each of the molten metal pools partitioned by the isolation means. continuous casting equipment.