JPH04129556U - Mold for horizontal continuous casting - Google Patents

Abstract

(57) [Summary] [Purpose] A lubricating body to reduce friction with the slab is
To provide a mold having advantages such as being hard to break, having a long life, and being easy to install. [Structure] A metal plate 23 in which a large number of small cylindrical lubricating bodies 24 are embedded is attached to a part of the inner surface of the mold 1.
That is, it was attached to the part that contacts the slab 5 inside the cooling mold 21 in the latter part.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention solidifies molten metal to form a slab or further cools the slab. This relates to a horizontal continuous casting mold used for horizontal continuous casting.

0002

[Conventional technology]

In continuous casting, molten metal is injected into a cylindrical mold through a tundish. It is then cooled and molded into a circular or rectangular shape that follows the shape of the mold (the cross-sectional shape of the hollow shaft). The slab is made into a slab with a cross-section of , and is continuously pulled out using a drawing device.

0003 The inner surface of the mold that comes into contact with the slab (or unsolidified cast metal) is Usually, a mold made of copper (or copper alloy) with excellent heat conductivity is placed and the outside is water-cooled. However, sufficient lubrication must be provided between the inner surface and the slab. That's right Otherwise, friction may increase the pull-out resistance and cause slab sticking (seizing). This is because the mold may be damaged by For this reason, so-called vertical continuity In the casting method, powder, oil, etc. are released from the opening at the upstream end of the mold during casting. lubricant is added.

0004 However, the mold with its axis horizontal is connected directly to the tundish. In the horizontal continuous casting method, it is difficult to add such lubricant, so oscillator The slab is pulled out while applying motion (or intermittent motion), and the mold itself Provides lubricity. For example, when casting steel using the horizontal continuous casting method, a certain After the slab (solidified shell) has a certain thickness and strength, the frictional force against it is reduced. To ensure this, lubrication treatment is primarily applied to the downstream side of the mold. like this Regarding lubrication, conventional horizontal continuous casting molds, for example, It is configured as follows.

[0005] b) As described in Japanese Patent Publication No. 60-55212, solid lubricants are included. Apply metal plating (or thermal spraying) to the inner surface of the mold. Similar technology is It is also introduced in Publication No. 57-14258.

[0006] b) As shown in Figures 5(a) and (b), solid lubricants such as graphite A lubricating body 62 with a large area is attached to the inner surface of the mold 61. using bolts etc. If the lubricant 62 is fixed in the mold 61, it will easily break at that point. It is attached by shrink fitting into a rectangular recess. circular cross-section mold In this case, the cylindrical lubricating body is also attached to the inside of the mold by shrink fitting etc. Ru.

[0007]

[Problem that the idea aims to solve]

The conventional molds described above each have the following problems.

[0008] First of all, molds with plating applied to the inner surface of the mold as shown in a) have a plating layer etc. Because the area containing the lubricant is thin (generally less than 0.5 mm), its effectiveness does not last long. It's hard to continue. In particular, repair the inner surface that has been damaged due to several uses by grinding. If you try to remove it, most of the same part will be lost during grinding, and you will need to plate it again. There are many things that must be done. Additionally, in general, plating containing solid lubricants is It's not something that can be done easily.

[0009] On the other hand, in a mold with a lubricant attached as in (b) above, the lubricant may be damaged. Cheap. Solid lubricants, which are much more brittle than metals, can be applied to large-area plates or hollow Because the lubricating body is formed in a cylinder, the lubricating body like the one above will not be affected by local force. It breaks easily. Also, each time a lubricant is damaged, a lubricant of the same size is required. This increases operating costs. Furthermore, a mold equipped with a lubricating body as shown in FIG. Now, when grinding the inner surface roughened by use, not only the lubricating body but also the copper (copper alloy) ) will have to be ground, which will shorten its lifespan.

0010 The purpose of this invention is that the lubricating body is hard to break, has a long life, and is easy to install. Advantages include no need to reapply another lubricant (plated layer, etc.) during surface grinding. An object of the present invention is to provide a horizontal continuous casting mold having the following features.

[0011]

[Means to solve the problem]

The horizontal continuous casting mold of the present invention as described in claim 1 is characterized in that the mold for horizontal continuous casting of the present invention is A large number of lubricants (graphite, boron nitride, disulfide molybdenum, A solid material made of a self-lubricating material such as Livdene is embedded. child Here, "many lubricating bodies" refer to large-area (therefore a small number of) lubricating bodies as shown in Figure 5. Rather than pointing to the lubricating body, each ``Pieces'' means a large number of small areas scattered on the inner surface of the mold. Ru. In addition, "a part of the inner surface" refers to the inner surface of the mold (the inner surface of the cooling mold and other inner surfaces). For example, among the surfaces surrounding the hollow shaft part of the mold to be in contact with the slab, The part on the downstream side (near the exit) along the single drawing direction and the lower surface that receives the weight of the slab As expected, the lubricant is scattered throughout the entire inner surface of the mold, including these parts. This also includes cases where it is embedded. Needless to say, the lubricating body is not shrink-fitted or adhesive. Fix it to the inner surface of the mold by using

0012 In the mold of claim 2, a metal plate in which a large number of lubricating bodies are embedded is cooled and cast. It is attached to the inside of the mold in contact with the slab.

[0013]

[Effect]

In the horizontal continuous casting mold of the present invention (claim 1), The lubricating body may come into direct contact with the slab, or the powder of the lubricating body may spread to the inner surface of the mold. By doing this, the friction between the inside of the mold and the slab is reduced, and the gap between the two is reduced. Prevent ticking. If the inner surface of the mold is made of copper, etc., bury the lubricant. The amount of heat transferred per area from the slab is slightly lower than when it is not inset, but The cooling characteristics of a mold depend on the mold length, etc., as well as the density of lubricating bodies (embedding spacing). Since it can be adjusted anywhere, it can be set freely rather than in the mold shown in Figure 5. can.

[0014] In this mold, a large number of small lubricating bodies are placed on the inner surface of the mold. Because it is embedded, the lubricating body may crack during casting or mold maintenance. Even if the lubricating body breaks, which is rare, the replacement lubricating body is small and will not be necessary. Lubricant embedding, which requires little cost, can be achieved by using lubricant-containing plating or In-mold spraying is much easier and faster than spraying on the inside of the mold. The buried depth of the lubricant from the surface should be made sufficiently larger than the wear margin of the mold. This prevents the lubricating effect from being lost in a short period of time due to wear, and the molding This has the advantage that there is no need to reapply the lubricant when the inner surface of the blade is ground.

[0015] Also in the mold of claim 2, the lubricating body embedded in the metal plate has the above-mentioned Similarly, it provides lubrication between the inner surface of the mold and the slab. This mold uses a lubricating body. Since the slab is cooled through the metal plate that contains it, it is important to This depends on the material and thickness of the metal plate, as well as the state of contact between the plate and the cooling mold. It is necessary to consider both.

[0016] In the mold of claim 2, the metal plate is replaceably mounted on the inner surface of the mold. In addition to the above points, if the mold is used for a long period of time and The cooling mold does not wear out even if the inner surface is repeatedly ground, so the metal plate can be cooling mold (which is more expensive than a metal plate because it has cooling water passages) It has the advantage that it can be used permanently.

[0017]

【Example】

FIGS. 1(a), (b), and (c) show a mold 1 as a first embodiment of the present invention. figure As shown, mold 1 is for horizontal continuous casting, with the shaft center horizontal and the connection refractory It is used by directly connecting to the tundish 2 with the object 3 in between, and in this example, it has a rectangular cross section ( A steel slab 5 having a long side dimension of approximately 200 mm is cast. Inside tundish 2 The molten steel 4 flows into the water-cooled interior of the mold 1 (the hollow shaft part) and is cooled. As a result, it solidifies from the outside and becomes a slab 5, which is then transferred to a drawing device (not shown) on the downstream side. It is pulled out by.

[0018] As shown in FIG. 1(a), the mold 1 consists of a former mold 10 and a latter mold 20. It consists of two parts. The mold 10 in the front stage is the tundish 2. An initial solidified shell is formed at the outermost periphery of the molten steel 4 immediately after it flows into the mold. The mold 20 securely protects the surface of the slab 5, which tends to shrink and deform as the solidification thickness increases. This is the part that comes into contact with and advances its cooling. Therefore, the hollow shaft part with a rectangular cross section is While the mold 10 has a surrounding integral cylindrical mold 11, the mold 20 has As shown in FIG. 1(c), a plate-shaped movable mold 2 faces each of the four sides around the slab 5. It has a total of four pieces of 1. Each mold 21 has a fixed frame 2 as shown in FIG. 1(a). The slab is pressed against the slab 5 by the spring 25 provided in the slab 6. This maintains contact with the slab 5 and contributes to uniform cooling of the slab 5. These molds 11・ 21 is made of copper alloy, and a cooling water passage jacket 12, 2 is provided on the outside thereof. 2 are each equipped. The symbols 12a and 22a in the figure represent the respective jackets 12 and 22a. 22 main body, 12b and 22b are cooling water introduction pipes, 12c and 22c are the cooling water The discharge pipes 12d and 22d are also partition walls for cooling water. In addition, in Figure 1(c) As shown, grooves 21a are formed on the outside of the mold 21 to increase the cooling effect. The mold 11 is also provided with similar grooves and cooling water passages (not shown).

[0019] Now, in this mold 1, a cylindrical (tablet-shaped) lubricating body 24 made of graphite A large number of are embedded in a copper plate 23 as shown in FIG. 1(b), and this plate 23 is The inner surface of the mold 20 in the latter stage, that is, the part on the inside of the mold 21 that contacts the slab 5, is stretched. It is attached. Each lubricating body 24 is located in a hole penetrating from the inner surface to the outer surface of the plate 23. It is fixed by shrink fitting (heating the plate 23 and fitting it in). Attach the plate 23 to the mold 21 with bolts 21b as shown in Figure 1(c). There is. Therefore, the above-mentioned mold 21 being pushed by the spring 25 is exactly For example, the plate 23 may be in contact with the slab 5 through a plate 23 provided with a large number of lubricating bodies 24. It becomes.

[0020] The lubricating body 24 keeps the slab 5 against the mold 1 due to the self-lubricating property of graphite. It facilitates movement (pulling out), but since each is small, it is highly rigid and the surrounding area is made of copper. Because it is held in place by a plate 23 made of aluminum, it is extremely difficult to break. So In addition, scratches caused by the slab 5 occurred on the inner surface of the plate 23 including the lubricating body 24. In such cases, the function of mold 1 can be completely restored by simply grinding its inner surface. Needless to say, attaching and removing the plate 23 before and after grinding requires bolts. It is also worth mentioning that this can be easily done by attaching and removing the cover 21b.

[0021] Regarding the size (surface area) of each lubricating body 24 on the plate 23, the burial interval, etc. In this case, the total surface area of the lubricating body 24 is about 20 to 60% of the entire surface area of the plate 23. It is preferable to keep it at a certain degree. If it is less than 20%, the lubricity will not be sufficient, This is because if it exceeds 60%, there is often little advantage in terms of strength. Also made of copper When embedding the graphite lubricant 24 in the plate 23, the embedding density ( The higher the surface area ratio (above), the more the heat transfer is suppressed and the slab 5 is cooled more slowly. Therefore, the burial density is determined by the cross-sectional dimension of the slab 5 as well as the length of the buried portion. It is best to determine it according to the method and steel type (cracking susceptibility, etc.).

[0022] As shown in FIG. 1(b), in this embodiment, each lubricating body 24 is exposed on the surface of the plate 23. Although the shape is circular, it goes without saying that the shape does not have to be circular. Ta For example, as shown in FIG. 2, a plate 33 in which a large number of oval lubricating bodies 34 are embedded. Even if it is used in place of the above plate 23, it will not affect the function and effect of the mold 1. Because there is no difference. In addition, in both the plates 23 and 33, the lubricating body 2 Holes for embedding 4 and 34 can be easily shaped by drilling or milling. Can be done.

[0023] Next, FIG. 3 shows a mold 40 which is a second embodiment of the present invention. First embodiment While the mold 1 of 1 was used to obtain a slab with a rectangular cross section, this mold 40 This is a horizontal continuous casting mold that produces slabs with a circular cross section.

[0024] The mold 40 is a movable (split type) mold like the latter part of the mold 1. Although the water jacket 45 is not equipped with a cold part, there are Two integral cylindrical molds 41 and 42 are assembled on the same axis. two Both molds 41 and 42 are made of copper alloy, but the upstream mold 41 is made of high-temperature molten steel. Because it comes into direct contact with the mold, it is a material with slightly better thermal properties than the downstream mold 42. It is formed.

[0025] Now, in this mold 40 as well, a cylindrical lubricant is provided inside the mold 42 on the downstream side. A plate 43 formed into a cylindrical shape (tube) in which a number of bodies 44 are embedded is attached. Ru. Similar to the first embodiment, the lubricating body 44 is made of graphite and the plate 43 is made of copper alloy. However, this plate 43 is shrink-fitted into the mold 42 (the mold 42 is heated up). It is fixed by fitting the plate 43.

[0026] Since this mold 40 is equipped with such a plate 43, the mold 40 also has friction between it and the slab. There is less friction and problems such as sticking are less likely to occur. Moreover, each lubricating body 44 It is difficult to break, and it is easy to attach and remove the plate 43 and re-grind its inner surface. It has the advantage that the same mold 42 can be used for a long period of time (semi-permanently) The mold 1 is also the same as the mold 1 of the first embodiment. Note that the lubricating body 4 on the plate 43 The burial density of No. 4 can also be determined based on the same consideration as above.

[0027] The mold of the third embodiment shown in Figures 4(a) and (b) (illustration of water jacket etc. is omitted) ), the inner surface of the mold 51 (but A lubricating body 52 is directly embedded in the inner surface of the mold. mold 51 The lubricating bodies 52 buried in the downstream part are each long in the casting direction, and the lubricating bodies 52 are buried in the downstream part. The end portion is rounded and the downstream end portion is a flat surface aligned with the downstream end surface of the mold 51. So In the thickness direction (radial direction in the mold 51), the lubricating body 52 extends inside the mold 51. ・It has dimensions that do not span the outer surface, and occupies only a part of the thickness (inner surface) of the mold 51. I'm looking forward to it.

[0028] In this mold, when the inner surface is damaged, each time it is ground again, the mold is Although it is inevitable that the mold 51 will wear out little by little and its life will be shortened, the lubricating body 5 2 is hard to break, and even if it does break, it can be easily repaired at low cost, and it is not plated. It has the advantage of having a much longer lasting effect.

[0029] Several examples have been introduced above, but regarding this invention, for example, the following Various embodiments are possible.

[0030] a) In addition to graphite, graphite fluoride, boron nitride, and molybdenum disulfide can be used as lubricants. Various self-lubricating solid materials can be used, such as.

[0031] b) The location where the lubricant is embedded in the mold is also not limited to the above example. Not possible. For example, a mold that receives the weight of the slab and tends to increase the frictional force with it. It is also a good idea to embed a lubricant only on the bottom surface of the Solidification temperature is slightly low, including non-ferrous metals. Casting metal materials (thus, the temperature of the molten metal flowing into the mold is not high) In some cases, it may be appropriate to embed a lubricant throughout the entire area from the upstream end.

[0032] c) A very common mold that is directly connected to the tundish in horizontal continuous casting. So-called cooling, which may be located downstream of the Plate (or support plate. Although the name is different, the function is very similar to that of a mold. The present invention can also be applied to This is explained in the first example above. A mold similar to the latter mold (number 20 in Figure 1) is used in a tundish or general mold. It is nothing but something placed downstream, separated from the field.

[0033] d) When a lubricating body is embedded in a metal plate as in claim 2, the metal plate Materials other than copper and copper alloys can also be used as the material. Especially under the mold. When applying only to the downstream part or when casting materials with a low solidification temperature, Saho Since very high thermal conductivity is not required, it is cheap and has some It is also advantageous to use metals that have self-lubricating properties.

[0034] e) Depending on the type of metal material to be cast, the mold of this invention may be used for vertical continuous casting. It is not impossible to apply it to construction.

[0035]

[Effect of the idea]

The horizontal continuous casting mold of the present invention has the following effects.

[0036] 1) Lubrication that facilitates the drawing of slabs and protects the inner surface of the mold. The body rarely breaks during casting or mold maintenance. Also, if Even if it is damaged, the cost of repair is low.

[0037] 2) There is no wear on the lubricating body, and the inner surface of the mold, which has become rough due to use, can be cleaned. The lubricant remains even after re-grinding, so the lubrication effect lasts for a long time.

[0038] 3) Attaching the lubricating body to the mold (in the mold of claim 2, the metal plate It is easy to attach the lubricant to the plate and attach the same plate to the mold. Ru.

[0039] In addition to the above-mentioned 1) to 3), the mold of claim 2 also has the following effects.

[0040] 4) Cooling must be relatively expensive due to the presence of cooling water passages and grooves. The mold can be used permanently.

[0041] 5) The metal plate containing the lubricant can be easily attached to the mold using bolts, etc. Can be attached.

[Brief explanation of drawings]

FIG. 1 is a drawing of a horizontal continuous casting mold 1 which is a first embodiment of the present invention, in which FIG. 1(a) is a cross-sectional view cut in the axial direction, and FIG. -b arrow view, same (c)
is a sectional view taken along line CC in FIG.

2 is a plan view (corresponding to FIG. 1(b)) showing another metal plate that can be applied to the mold 1 of FIG. 1. FIG.

FIG. 3 is a cross-sectional view in the axial direction of a horizontal continuous casting mold 40 according to a second embodiment of the present invention.

[Fig. 4] Regarding the horizontal continuous casting mold (partially not shown) which is the third embodiment of the present invention, Fig. 4(a) is a cross-sectional view in the axial direction, and Fig. 4(b) is a view from the downstream end. It is a front view.

[Fig. 5] A drawing showing a conventional horizontal continuous casting mold.
Figure 5(a) is a cross-sectional view taken perpendicular to the axis, and Figure 5(b) is the same.
It is a bb arrow view in (a).

[Explanation of symbols]

1.40 mold 5 Slab 11/21/41/42/51 Cooling mold 23・33・43 Metal plate 24・34・44・52 Lubricating body

Claims (2)

[Scope of utility model registration request] 1. A mold for horizontal continuous casting, characterized in that a plurality of lubricating bodies are embedded in a part of the inner surface in contact with the slab. 2. The horizontal continuous casting mold according to claim 1, wherein a metal plate is attached to a portion of the inside of the cooling mold that contacts the slab, and the plurality of lubricating bodies described above are embedded in the plate.