JPH0244618B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The technical content described in this specification regarding an electromagnetic stirring continuous casting machine is to achieve an electromagnetic stirring mold capable of cutting a water-cooled copper plate using an assembled mold. .

In continuous casting, in-mold electromagnetic stirring is often used to improve surface quality by preventing bubble defects in the surface layer of slabs and to improve internal quality by increasing equiaxed crystallinity. In order to prevent the electromagnetic force acting from the outside from attenuating, electromagnetic stirring molds have thin copper plates and copper back-up plates to reduce the distance between the inside of the mold and the electromagnetic stirring device. The copper plate is integrally formed.

However, in the case of an integrated copper plate, if the inner surface of the copper plate is scratched or worn, it cannot be ground, and the copper plate becomes disposable, which increases the cost of the copper plate. An assembled type that can perform copper plate cutting is desirable.

(Conventional technology) As a conventional assembly mold, Utility Model 57-26949
There are techniques disclosed in Japanese Patent Application Laid-Open No. 57-31444.

In the former method, the backup plates are supported by a mold frame having a two-part structure, and the backup plates are fastened together with bolts, and the gap between the mating surfaces of the copper plates is adjusted using a liner.

The latter has a wedge mechanism added to the former liner.

(Problems to be Solved by the Invention) By the way, in order to employ these assembled molds in an electromagnetic stirring continuous casting machine, the copper plate and back-up plate must be made thinner to prevent the electromagnetic stirring force from attenuating. The problem remained that if it was made thinner, it would lack strength, making it impossible to secure the strength required for the mold.

This invention advantageously solves the above-mentioned problems, and not only improves the quality of slabs by electromagnetic stirring, but also reduces the cost of copper plates by using assembled copper plates. The purpose of this study is to propose an electromagnetic stirring continuous casting machine that is strong enough to withstand normal operation.

(Means for solving the problem) That is, the present invention forms a cooling passage for guiding a cooling water flow between a water-cooled copper plate and its backup plate, and defines a casting space by a combination of the water-cooled copper plates. A mold for electromagnetic stirring, comprising a mold assembly consisting of a mold assembly, a mold frame for supporting the mold assembly, and an electromagnetic stirring device for forcing stirring flow into molten metal introduced into a casting space of the mold assembly, (a) The mold frame is divided into upper and lower parts so that the inner space of the lower frame is large, and the mold assembly is attached to the upper frame, while the electromagnetic stirring device is held by the lower frame; (b) ) Fixing the mold assembly to the mold frame by pressing force from four sides using holding bolts installed at least above and below the lower frame; , a mold for electromagnetic stirring characterized by providing a cooling water supply and drainage passage to a cooling passage of a mold assembly.

The mold used for continuous bloom casting will be described in more detail below with reference to the drawings.

A preferred mold is shown in cross section in Figure 1a and Figure 1b.
shows the A-A arrow plane, respectively.

Numbers 1 and 2 in the figure are water-cooled copper plates (hereinafter simply referred to as copper plates) that constitute the peripheral wall of the mold.Backup plates 3 and 4 are applied to the back of each copper plate, and the backup plates 3 and 4 are connected with connecting bolts. 5, the inner copper plates 1 and 2 are connected to each other and integrated.
The ends of the copper plates 1 and 2 are fitted together to form a mold assembly. Here, the contact surfaces for joining the copper plates to each other are 1a and 2a, but since it is sufficient to fix only the copper plates, the tightening force by the connecting bolt 5 is small compared to the force for fixing the whole. Therefore, even if the copper plate is made thinner, 1a,
The hit surface of 2a is sufficient.

Also, copper plates 1 and 2 and backup plates 3 and 4
A cooling passage 7 for the cooling water 6 is formed between the A drain port 9 is provided.

Furthermore, as shown in FIG. 1b, the mold frame 10 surrounding the mold assembly consisting of the copper plates 1, 2 and the back-up plates 3, 4 is designed so that the internal space of the lower frame 10b is large. B-
It can be divided into an upper frame 10a and a lower frame 10b along the line B. Upper and lower frames 10
A and 10b are connected by attaching the upper frame 10a to a connecting bolt 11 fixed to the lower frame 10b and then fastening with a connecting nut 12. The inside of the upper frame 10a is a passage 10c for the cooling water 6, and the upper frame 10a has flanges 3a,
Cooling water 6 is supplied and discharged through holes provided on the lower surface of 4a that communicate with supply and drain ports 8 and 9, respectively.
The inside of the lower frame 10b is partitioned into two rooms, one of which is a water supply passage 10d for the cooling water 6.
Next, the other room is used as a place for installing an electromagnetic stirring device 13 (hereinafter simply referred to as stirrer 13).

The upper frame 10a of the mold frame 10 includes:
The mold assembly consisting of the copper plates 1 and 2 and the backup plates 3 and 4 is attached using the fixing bolts 14. Prior to this, the assembly is held down by the bolts 1.
5 to the mold frame. The presser bolts 15 are required at at least two locations above and below the stirrer 13, but it is preferable to arrange a presser metal fitting 16 at least at the lower portion. That is, both ends of this presser metal fitting 16 are fixed to two presser bolts 15 at the top and bottom of the mold frame 10.
It is inserted into the holder and held so that it can be moved horizontally. At this time, if a flat spring 17 is used as a pressing surface for the presser foot 16, the pressing force can be kept almost constant, and both ends of the presser foot 16 can be held by the presser bolts.
It is advantageous to clamp with a double nut engaged with 5 in order to prevent loosening. In particular, if there is not enough space on the upper side, the projecting portion of the back-up plate 3a may be directly pressed without using a presser as shown on the left side of FIG. 1a. Furthermore, the back surface of the backup plate 3a may be pressed directly.

Next, the mold assembly procedure begins with mold frame 1.
0, the stirrer 13 is fixed to the lower frame 10b with bolts 18, and then the upper frame 10a is fixed to the lower frame 10b. Note that the stirrer 13 is, for example, the lower frame 10b.
It is desirable that the bolt hole is made into a long hole so that the bolt 18 can move, and the position of the stirrer 13 can also be adjusted. Next, the backup plates 3 and 4 integrated with the copper plates 1 and 2 are inserted into the internal space of the assembled mold frame 10, and then horizontally positioned, preferably by the presser bolts 15 via the presser metal fittings 16. After fixing the
Attach the upper part of the backup plates 3 and 4 to the bolt 14.
It is fixed to the upper frame 10a by. The bolt holes in the back-up plates 3, 4 through which the bolts 14 pass are made elongated holes so that the plates 3, 4 can be moved, thereby making it possible to adjust the dimensions of the copper plates 1, 2 after grinding.

When the mold assembly is completed in this way, the supply/discharge passage for the cooling water 6 to the cooling passage 7 is also opened at the same time. Then, the cooling water 6 is sent from the oscillation table 19 to which the lower frame 10b is fixed to the water supply passages 10d and 10c through the water supply hole 20, and is supplied to the cooling passage 7 through the water supply hole 8. After making one cycle, it passes through the drain port 9 to the drain passage 10e, and is discharged to the outside via the oscillation table 19 through the drain hole 21. It is preferable that the joints between the upper and lower frames 10a, 10b and the backup plates 3, 4 and the upper frame 10a be hermetically sealed using a sealing material 22 such as an O-ring.

Note that Figures 1a and b above show the case where the presser metal fittings are placed on all four sides at the bottom of the assembly, but if it is not necessary to adjust the mold size for cutting the short side of the copper plate, , the presser foot only needs to be placed on the two long sides.

(Function) When molten steel is received into the assembled mold and continuous casting is performed, stirring occurs in the molten steel due to the action of the stirrer 13, but since the copper plates 1 and 2 and the back-up plates 3 and 4 are thinned, the molten steel On the other hand, the stirrer 13 can be moved close to each other, and since the inner space of the lower frame 10b is wide, the stirrer 13 is taller.
3, it is possible to provide a large electromagnetic stirring force. Furthermore, since the strength of the mold is provided by the presser metal fitting 16 and the presser bolt 15 that clamp the backup plates 3, 4, there is no adverse effect due to the thinning of the backup plates 3, 4.
Furthermore, changes in mold internal dimensions due to thermal expansion of the copper plates 1 and 2 that occur during continuous casting are dealt with by deformation of the bell springs 17.

After grinding the copper plates 1 and 2, the back-up plates 3 and 4 are moved inward, so the external dimensions c and d of the plates 3 and 4 change. adjust. At this time, it is desirable to also adjust the position of the stirrer 13.

Further, the supply and discharge of the cooling water 6 to the cooling passage 7 can be ensured by the seal mechanism 22 even if the backup plates 3 and 4 are moved after the copper plate is ground.

(Effects of the invention) The effects of this invention are summarized as follows.

(1) As it has become possible to apply assembled copper plates to electromagnetic stirring molds, which was previously difficult to apply, it is now possible to shave copper plates even in electromagnetic stirring continuous casting, reducing copper plate costs and manufacturing costs. can be achieved.

(2) Since the copper plate and backup plate can be made thinner and the stirrer can be made larger, the stirring capacity can be increased.

(3) Since the structure is divided into upper and lower parts, it is easy to assemble the stirrer, and the copper plate can also be integrated with the backup plate, so assembly is easy and maintenance is excellent.

[Brief explanation of the drawing]

FIGS. 1a and 1b are a cross-sectional view and a cross-sectional view taken along the line A--A of the mold according to the present invention, respectively. 1, 2... Copper plate, 3, 4... Backup plate, 5... Connection bolt, 6... Cooling water, 7...
Cooling passage, 8... Water supply port, 9... Drain port, 10...
...Mold frame, 11...Connecting bolt, 12...
Connection nut, 13... Stirrer, 14... Fixing bolt, 15... Presser bolt, 16... Presser hardware,
17...Flat spring, 18...Bolt, 19...Oscillation table, 20...Water supply hole, 21...
...Drain hole, 22...Sealing material.

Claims (1)

[Scope of Claims] 1. A mold assembly comprising a cooling passage for guiding a cooling water flow between a water-cooled copper plate and its backup plate, and a casting space defined by a combination of the water-cooled copper plates; An electromagnetic stirring mold comprising a mold frame for supporting a mold assembly, and an electromagnetic stirring device for forcing stirring flow into molten metal introduced into a casting space of the mold assembly, the mold comprising: (a) the mold frame; (b) the mold assembly is attached to the upper frame while the electromagnetic stirring device is held by the lower frame; The mold assembly shall be fixed to the mold frame by pressing force from four sides using retainer bolts installed at least in the upper and lower two locations of the frame; (c) The mold assembly shall be cooled within the upper and lower two-part mold frame. An electromagnetic stirring mold characterized by having a cooling water supply and drainage channel to the passage.