JPH1157949A - Mold for continuous casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold for continuous casting which obtains long service life by forming hard and dense thermal sprayed film on the inner surface of long sides and short sides thereof. SOLUTION: In the mold for continuous casting, having one pair of long sides 11 and one pair of short sides arranged between one pair of long sides 11, the first thermal-sprayed film layers 13, 14 of autogeneous alloy, are formed on both inside side parts 12a of the long sides 11 slidingly abutted on the short sides and the inside lower parts 12b of the long sides 11 contacting with solidified cast slab shell, respectively. Further, the second thermal-sprayed film layers of the autogeneous alloy are formed on the inside lower parts of the short sides contacting with the cast slab shell, too.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting mold for continuous casting in which the inner surfaces of long and short pieces are hardened by thermal spraying to extend the life.

[0002]

2. Description of the Related Art Conventionally, a curved continuous casting machine G shown in FIG. 16 has been widely used as one form of a continuous casting machine for continuously casting molten steel. The curved continuous casting machine G is a two-strand type continuous casting machine in which two continuous casting molds H are arranged between a pair of back frames 80 supported in parallel. As shown in FIG. 17, each mold H has a pair of long pieces 81, 81a and a pair of short pieces 82, 82a arranged between the pair of long pieces 81, 81a.
It is provided with.

[0003]

However, in the conventional mold H, when molten steel is continuously cast, powder is interposed between the inner surface of the mold H and the slab 83. At the bottom of the mold H where the shell becomes thicker,
The inner surface of the soft mold H is worn by the thick and hard slab shell. For this reason, the dimension of the mold H changes, and the slab 8
In addition to the decrease in dimensional accuracy of No. 3, an air gap is generated between the mold H and the slab 83, the thickness of the slab shell becomes nonuniform, and the slab 83 tends to be vertically cracked. Further, when the molten steel is continuously cast, the long pieces 81, 81a and the short pieces 82, 82a of the mold H are each thermally expanded (particularly, in a portion near the meniscus of the molten steel (see FIG. 18E)). . At this time, for example, as shown in FIG.
A corner overhang portion 84 occurs in which the inner portions of both ends of each short piece 82, 82a overhang, and after continuous casting,
This corner overhang portion 84 is called "caulking hammer"
It is necessary to perform the operation of undoing by tapping with etc.

Further, as shown in FIG. 18 (b), the short pieces 82, 82a are thermally expanded, and the inner portions at both ends bite into the inner surfaces of the long pieces 81, 81a, and the pressing flaw 85 is formed. As shown in FIG. 18 (c), when the amount of molten steel in the mold H decreases and the short pieces 82 and 82a thermally shrink at the end of continuous casting or during the ladle exchange period of continuous casting, , A corner gap g occurs. Therefore, at the time of the next continuous casting, molten steel or the like is inserted into the corner gap g, and stable operation cannot be performed. That is, each of the long pieces 81, 8
If the slits for passing cooling water are not provided inside both sides of 1a, the cooling capacity at the corners in the mold will be low, and the molten steel inserted into the corner gap g will not be easily solidified, and the slab shell will be formed thick. And restrictive breakout is more likely to occur.

Recently, each of the short pieces 82, 8
A variable width mold that slides 2a along the longitudinal direction of each long piece 81, 81a is becoming mainstream. However, in this case, as shown in FIG. 18D, scratches h occur on the inner surfaces of the long pieces 81 and 81a. For this reason, even if the above-mentioned powder tries to flow downward, it enters the abrasion flaw h and cannot be evenly interposed between the mold H and the slab 83. Therefore, the slab shell is welded to the inner surface of the mold to cause a breakout, and the cooling ability of the mold H becomes non-uniform. In addition, there is also a problem that the inner surface of the mold is significantly worn due to the corner gap g and the abrasion f described above. Then, the present inventors, as shown in FIGS. 19 (a) and (b), use Ni plating 88 on the entire inner surface of the base material 87 of each long piece 86.
Is formed, and C is formed on the entire upper surface of the Ni plating 88.
A mold having r plating 89 formed thereon was proposed.

Japanese Patent Publication No. 60-39654 discloses that, in a base material of a long piece, Ni is provided on both inner side portions where the short pieces are in sliding contact with each other and on an inner lower portion where the slab shell contacts.
In addition to forming the plating, a Ni alloy plating is formed on the entire inner surface of the base material so as to cover the Ni plating.
A mold in which Cr plating is formed on the entire upper surface of i-alloy plating has been proposed. However, in this case, FIG.
(B) As shown in FIG.
Occurs, between the surface Cr plating 89 and the underlying Ni plating 88, and in the mold described in the above publication, the surface Cr plating and the underlying Ni plating 88
A potential difference is generated between the plating and the alloy plating to form a local battery (see FIG. 19 (c)), and the pitting corrosion p proceeds (FIG. 19).
(See (d) and (e)). Therefore, the present inventors have further proposed a mold shown in FIGS.

That is, this mold is obtained by removing the above-mentioned Cr plating on the surface layer.
As shown in FIG.
1 on the upper surface of the Ni plating 91, and Ni-C on the inner lower portion 91a touched by the slab shell, and Ni-C
o plating 92, 92a is formed, and in the short piece 97,
As shown in FIG. 21, Ni plating 95 is formed on the entire inner surface of the base material 94, and Ni plating 95 is formed on the inner lower portion 95a.
-Co plating 96 is formed. However, in this case, although the problem of the pitting corrosion is solved, the above-mentioned problem of the corner gap g, the scratches h, and the problem of shortening the life of the mold caused by these problems cannot be solved.
It was necessary to replace it with about 00 charges. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a continuous casting mold in which a hard and dense sprayed coating layer is formed on the inner surface of a long piece or a short piece to extend the life.

[0008]

According to the present invention, there is provided a semiconductor device comprising:
The continuous casting mold according to the present invention is a continuous casting mold having a pair of long pieces and a pair of short pieces disposed between the pair of lengths, wherein each of the short pieces is in sliding contact with each other. A first thermal spray coating layer of a self-fluxing alloy is formed on both inner side portions and a lower inner portion of the long piece contacted by the solidified slab shell, and the inside of the short piece touched by the slab shell. A second thermal spray coating layer of a self-fluxing alloy is also formed on the lower portion. In addition, only the inner side and lower side of the long piece are the first.
It is also possible to form the thermal spray coating layer of the above, or conversely, to form the second thermal spray coating layer only on the lower inside of the short piece.

Further, the continuous casting mold according to claim 2 is
2. The continuous casting mold according to claim 1, wherein at least a portion adjacent to the first sprayed coating layer on an inner upper portion of the long piece and at least an inner upper portion of the short piece, at least on the second sprayed coating layer. 3. Ni or Ni alloy plating is formed on adjacent portions, respectively. Note that at least a portion adjacent to the first sprayed coating layer on the inner upper portion of the long piece is N
It is also possible to form the i or Ni alloy plating, or conversely, to form the Ni or Ni alloy plating only on the inner upper portion of the short piece and at least the portion adjacent to the second thermal spray coating layer. The Ni alloy plating includes Ni-Co plating, Ni-Fe plating and the like.

Further, the continuous casting mold according to claim 3 is
In the continuous casting mold according to claim 1 or 2, the inner upper portion of the long piece, and the surface layer of the inner upper portion of the short piece,
Cr plating is formed respectively. It is also possible to form Cr plating only on the upper surface layer of the inside of the long piece, or conversely, to form Cr plating only on the upper surface layer of the inside of the short piece. The Cr plating may be formed directly on the surface of the base material of the mold, or may be Ni or Ni formed on the surface of the base material.
It may be formed on alloy plating.

Here, both inner side portions of the long piece refer to a portion where the short piece abuts in a fixed width mold and a portion where the short piece abuts in a variable width mold. In addition, when the molten steel is continuously cast, it may be slightly wider (for example, about 10 to 20 mm) in consideration of the case where the inner portions of both ends of the short piece protrude inward (see FIG. 18A). is there. In addition, the inner lower part of the long piece or the short piece is not particularly limited as long as it is a part that the slab shell (may be a slab) touches during continuous casting of molten steel. Of course, if the range of the inner lower portion is lower than the meniscus of the molten steel stored in the mold during the continuous casting of molten steel, the first and second portions are affected by the heat near the meniscus where the temperature becomes the highest. 2
In the worst case, the first and second sprayed coating layers can be prevented from generating heat cracks in the sprayed coating layer.

[0012] Specifically, the length piece and the lower end of the short piece of about 1 / 5-3 / 5 of about the total height (L _1), preferably about 2
It is desirable to be about ５〜 to ／. This is because, when the range of the “inner lower portion” is less than ／ of the total height from the lower end, the effect of preventing the mold from being worn by the first and second sprayed coating layers is reduced, and particularly, 1 / の of the total height. If it is less than 5,
This is because the tendency becomes remarkable. Conversely, if it exceeds 3/5 of the total height, the production cost rises, and as described above, heat cracks are easily generated in the first and second sprayed coating layers. In addition, as a method of forming the first and second sprayed coating layers on the above-described portions, a flame spraying method, an arc spraying method, a plasma spraying method, a high-speed flame spraying method, or the like can be applied. desirable. The flame (flame) speed of high-speed flame spraying is normal flame spraying (about 300 m /
Second) and plasma spraying (about 800 m / sec) (about 2000 to 2700 m / sec), so that a hard and dense sprayed coating layer can be formed on the above-mentioned portion, and the life is extended. This is because

In addition, the Ni or Ni alloy plating is formed not only on the inner upper portion of the long piece and adjacent to the inner lower portion, but also on the inner upper portion of the short piece and adjacent to the inner lower portion. It may be formed on the inner upper part of the piece, or over the entire inner upper part of the short piece. At this time, Ni or N
When the i-alloy plating is formed, it is possible to prevent local abrasion due to the difference in hardness from occurring at the boundary between the inner upper part of the long piece or the short piece and the thermal spray coating layer. When Ni or Ni alloy plating is formed on the base material, the copper or copper alloy base material can be prevented from being oxidized and brittle.
It is also possible to form a Cr plating on the Ni or Ni alloy plating formed on the adjacent portion. Also, when the thickness of the thermal spray coating layer or the Ni or Ni alloy plating is increased from the upper part to the lower part of the long piece or the short piece, the wear resistance to the cast piece can be improved.

Therefore, in the continuous casting mold according to claims 1 to 3, the inner lower part of the long piece and the inner lower part of the short piece are
Since the first and second sprayed coating layers of a dense and hard self-fluxing alloy are formed, wear due to the cast piece can be prevented, the life of the mold can be extended, and the dimensional accuracy of the cast piece due to the wear can be improved. The yield can be improved by preventing a decrease in cast iron slab quality. In addition, since the first sprayed coating layer of a dense and hard self-fluxing alloy is formed on both inner side parts of the long piece, the occurrence of press flaws and abrasion flaws due to expansion and contraction of the short piece during continuous casting is prevented. In addition to this, it is possible to prevent the occurrence of restraint breakouts or the like due to the pressing flaws and the rubbing flaws, thereby enabling stable operation, and also prevent the slab quality from lowering and the yield from lowering. In addition, when the above-mentioned portion is subjected to an appropriate roughening process in advance,
It goes without saying that the first and second thermal spray coating layers have good adhesion and are hard to fall off.

[0015] In particular, in the continuous casting mold according to the second aspect, a portion adjacent to the first sprayed coating layer (that is, both inner side portions and the inner lower portion) on the inner upper portion of the long piece, On the inner upper portion of the short piece and at a portion adjacent to the second sprayed coating layer (that is, the inner lower portion), the surface hardness of the base material of the long piece or the short piece and the first and second sprayed coating layers Since Ni or Ni alloy plating having a surface hardness in the middle of the surface hardness is formed, when continuously casting molten steel, when the solidified slab shell is continuously pulled down, the base material and the first and second thermal spraying are performed. Due to the difference in hardness of the coating layer, it is possible to prevent the occurrence of local wear in the above-described adjacent portion. Further, in the continuous casting mold according to the third aspect, since the Cr layer is formed on the upper inner surface of the long piece or the short piece, it is possible to prevent the base material from being oxidized and brittle, and The service life can be extended.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. Note that the same reference numerals are given to the same components in each embodiment, and the description will be omitted. (First Embodiment) First, a continuous casting mold A according to a first embodiment of the present invention will be described with reference to FIGS. The continuous casting mold A according to the present embodiment,
The difference from the conventional continuous casting mold H is that, as shown in the figure, the inner side portions 12a of the long pieces 11, 11a on which the short pieces 15, 15a slide and abut, and the solidified slab shell (shown in the figure). the inner lower 12b not) are in contact with the sliding person, respectively, Ni, Cr, Si, B, etc. of one or more kinds of self-fluxing alloy powder formed by spraying the thickness (t _3, t ₄₎ 0.1~
2 mm, first thermal spray coating layer 1 having a surface hardness of Hv 600 or more
3 and 14, respectively, and each short piece 15, 15a
Is formed by spraying one or more self-fluxing alloy powders of Ni, Cr, Si, B, etc.
₇ ) The second spray coating layer 17 having a thickness of 0.1 to 2 mm and a surface hardness Hv of 600 or more is formed. In the present embodiment, the width (L ₄ ) of the first sprayed coating layer 13
Is the sliding range of each of the short pieces 15 and 15a, and the vertical width (L ₅ , L ₆ ) of the first and second sprayed coating layers 14 and 17 respectively.
Was set to ５〜 to 全 of the total height (L ₁ ) of each of the long pieces 11, 11a and each of the short pieces 15, 15a.

Next, a method of manufacturing the continuous casting mold A having the above-described structure will be described with reference to FIGS. First, a method for manufacturing the long piece 11 will be described. First, both inner side portions 1 of a copper or copper alloy base material 12 are formed.
2a and the inner lower portion 12b are scraped off by about 0.1 to 2 mm using a surface grinder (not shown), degreased using an organic solvent, and then subjected to a blasting-based roughening treatment. At this time, the surface roughness Rz is selected in the range of 50 to 150 μm. This is because if the surface roughness Rz is less than 50 μm, the surface is too smooth and the adhesion of the sprayed coating is 10 kg /
cm ² or less and decreases, the surface roughness Rz is more than 150 [mu] m, because releasability and surface roughness of the thermal spray coating is increased is deteriorated. In this case, as the blast material (grid), alumina, steel, sand or the like can be used, and among them, alumina is preferable. This is because the effect of anchoring the sprayed coating can be increased. Then, as shown in FIG. 4, the first self-fluxing alloy powder is preferably applied to the portion subjected to the surface roughening treatment by using a high-speed flame spraying machine 18 so as to be flush with the inner upper portion 12c. Thermal spray coating layers 13, 14
To form

At this time, the high-speed flame spraying is performed by using kerosene (kerosene) as a fuel and combining it with oxygen to obtain 2400 to 2400.
At a high temperature of 2700 ° C., a high-speed gas jet of 2500 to 2700 m / sec is made, and the self-fluxing alloy powder is put on the jet and melted, and the sprayed material is mixed with the base material 12 at a high speed (for example, about 750 m / sec). It is solidified and joined by spraying the inner side portion 12a and the inner lower portion 12b. In this case, the particle size of the self-fluxing alloy powder to be sprayed is selected in the range of 10 to 50 μm.
This is because, for example, when the particle size of the self-fluxing alloy powder is less than 10 μm, the manufacturing cost rises and the momentum of the sprayed self-fluxing alloy powder becomes small, so that the self-fluxing alloy powder is easily flowed into the airflow. Conversely, if it exceeds 50 μm,
This is because the thermal sprayed coating tends to be coarse and the strength tends to be substantially reduced. When manufacturing the short piece 15, first,
After the inner lower part 16a of the base material 16 is scraped off by about 0.1 to 2 mm using a surface grinder (not shown), the ground lower part 16a is subjected to a surface roughening treatment. And
Similarly to the above, the second thermal spray coating layer 17 is formed under the same thermal spraying conditions as described above, preferably using a high-speed flame spraying machine 18 (see FIG. 4) so as to be flush with the inner upper portion 16b.
The manufacturing method of the long piece 11a and the short piece 15a is the same as that of the long piece 11 and the short piece 15, and the description thereof will be omitted.

As described above, according to the continuous casting mold A according to the present embodiment, both inner side portions 12 of the long pieces 11 and 11a are formed.
a and the lower inner portion 12b, first spray coating layers 13, 14 of a self-fluxing alloy are formed,
Since the second sprayed coating layer 17 of the self-fluxing alloy is also formed on the inner lower portion 16a of the 5a, it is possible to prevent the occurrence of press flaws and scratches, and to extend the life of the continuous casting mold A. Can be. Further, for example, when high-speed flame spraying, which has a higher flame speed than plasma spraying or the like, is applied, the first and second sprayed coating layers 13, 14,
17 can be increased, and the service life can be further extended.

(Second Embodiment) Next, FIGS.
A continuous casting mold B according to a second embodiment of the present invention will be described with reference to FIG. The continuous casting mold B according to the present embodiment is different from the continuous casting mold A as shown in FIG.
2c, the surface hardness (approximately Hv100) of the base material 21 is formed on the strip-shaped portion 12e adjacent to the first sprayed coating layer 14.
And the surface hardness of the first sprayed coating layers 13 and 14 (Hv600
Surface hardness (Hv 200 in the present embodiment)
Thickness having a _{degree) (t 8, t 5)} 0.1~2mm of N
The point where each of the i-plates 22 was formed and the short pieces 23, 2
3a, and the second sprayed coating layer 17
Also, the belt-like portion 16c adjacent to the surface hardness of the base material 24 (about Hv100) and the surface hardness of the second sprayed coating layer 17 (Hv600 or more) are intermediate (about Hv200 in the present embodiment). Having a thickness (t ₉ ) of 0.1 to 0.1
The point is that 2 mm of Ni plating 25 was formed.
In the present embodiment, the vertical width (L ₇ , L ₈ ) of each of the Ni platings 22, 25 is determined by the vertical width (L ₇ , L ₈ ) of each of the long pieces 20, 20 a and the inner upper portions 12 c, 16 b of each of the short pieces 23, 23 a. L ₂₀ , L ₂₁ ).

Next, with reference to FIGS. 1, 5, and 6, a method of manufacturing the continuous casting mold B having the above-described configuration will be described. First, a method for manufacturing the long piece 20 will be described. First, both inner side portions 12a and inner lower portion 12 of the base material 21 are formed.
After the b and the band-shaped portion 12e are scraped off by about 0.1 to 2 mm using a surface grinder (not shown), Ni plating is formed on the portion 12e so as to be flush with the non-ground portion (upper portion inside). As plating conditions at this time, for example, 350 liters of S-Ni (Ni sulfamate) in 1 liter of water is used.
g, 5 g of Ni chloride and 30 g of boric acid are used at an electrolyte temperature of 45 to 60 ° C. and a current density of 3 A / dm ² . Then, both or both of the inner side portions 12a and the boundary portion or the entirety of the inner lower portion 12b with the Ni plating 22 are
In the same manner as described above, a surface grinder not shown
Grind about 2 mm. As a result, an interface between the Ni plating 22 and the thermal spray coating described later is formed. Next, after roughening the ground portion, similarly to the above, preferably using the high-speed flame spraying machine 18 (see FIG. 4), the same spraying conditions as above are used, so that the surface becomes flush with the inner upper portion 12c. First thermal spray coating layers 13 and 14 are formed. And finally after spraying 12
The entire surface including a, 12b, 12c, and 12e is ground and ground. In the case of manufacturing the short piece 23, first, the inner lower part 16a of the base material 24 and the strip-shaped part 16c are scraped off by about 0.1 to 2 mm by a plane grinder (not shown).
At the portion 16c, Ni plating is formed under the same plating conditions as described above so as to be flush with the non-ground portion (upper portion inside).

Then, the Ni plating 25 on the inner lower portion 16a is formed.
Or the whole of the boundary portion is ground by about 0.1 to 2 mm from the surface by a surface grinder in the same manner as described above. This allows Ni
An interface between the plating 25 and the thermal spray coating described later is formed. Next, after roughening the ground portion, similarly to the above, preferably using a high-speed flame spraying machine 18 (see FIG. 4), the same spraying conditions as above are used, so as to be flush with the inner upper portion 16b. The second thermal spray coating layer 17 is formed. 16a, 16 after thermal spraying
The entire surface including b and 16c is ground. In addition, since the manufacturing method of the long piece 20a and the short piece 23a is the same as that of the long piece 20 and the short piece 23, the description is omitted. As described above, according to the continuous casting mold B according to the present embodiment, the same effect as that of the first embodiment of the present invention can be obtained, and the inner upper portion 12c of each of the long pieces 20, 20a, and The strip portion 12e adjacent to the first sprayed coating layer 14, the short piece 23,
The base material 2 is formed on the inner upper portion 16b of the base member 23a and on the strip-like portion 16c adjacent to the second sprayed coating layer 17, respectively.
Ni platings 22 and 25 having a surface hardness intermediate between the first and second spray coating layers 13, 14 and 17 are formed on the inner upper portions 12 c of the long pieces 20 and 20 a and the short pieces 23 and 23 a. From 16b, it is possible to prevent the occurrence of local wear due to the discontinuity in hardness over the inner lower portions 12b and 16a.

(Third Embodiment) Next, a continuous casting mold C according to a third embodiment of the present invention will be described with reference to FIGS. The continuous casting mold C according to the present embodiment is different from the continuous casting mold A, as shown in the drawing, in the upper inner portion 12c of each of the long pieces 26, 26a,
Moreover, the I-shaped portion 1 adjacent to the first thermal spray coating layer 13
2f, the surface hardness of the base material 27 (about Hv100
Degree) and the surface hardness (Hv) of the first sprayed coating layers 13 and 14.
600 or more (in this embodiment, Hv
Thickness with about _{200) (t 10, t 5} ) 0.1~2m
This is the point where m Ni plating 28 was formed. In the present embodiment, the width (L ₉ ) of each Ni plating 28 is set to 1/10 to 3/10 of the width (L ₂₂ ) of the inner upper portion 12c of each of the long pieces 26, 26a. The short pieces are the same as the short pieces 23 and 23a of the continuous casting mold B, and the description thereof will be omitted.

Next, a method of manufacturing the long piece 26 of the continuous casting mold C having the above-described configuration will be described with reference to FIG. First, the inner side portion 12a, the inner lower portion 12b, and the I-shaped portion 12f of the base material 27 are scraped off by about 0.1 to 2 mm with a plane grinding machine (not shown), and then the non-ground portion ( Ni plating is formed under the same plating conditions as described above so as to be flush with the upper part (inner side). And Ni plating 2 of both inner side parts 12a and inner lower part 12b
8 or about 0.1 to 2 mm from the surface by a surface grinder (not shown) in the same manner as described above. As a result, an interface between the Ni plating 28 and the thermal spray coating described later is formed. Next, after roughening the ground portion, similarly to the above, preferably using the high-speed flame spraying machine 18 (see FIG. 4), the same spraying conditions as above are used, so that the surface becomes flush with the inner upper portion 12c. First thermal spray coating layers 13 and 14 are formed.
Finally, after thermal spraying, 12a, 12b, 12c, 12
Grind the entire surface including f. The long piece 26a
The manufacturing method is the same as that described above, and the description is omitted.

As described above, according to the continuous casting mold C of the present embodiment, the same effects as those of the first embodiment of the present invention can be obtained, and the inner upper portion 12c of the long pieces 26, 26a can be obtained.
And the I-shaped portion 1 adjacent to both inner side portions 12a.
2f, the base material 27 and the first sprayed coating layer 13,
Since the Ni plating 28 having an intermediate surface hardness of 14 is formed, the base material 27 and the first material 12 are formed at the boundary between the inner upper part 12c and the inner side parts 12a, that is, the I-shaped part 12f.
In this case, it is possible to prevent heat cracks due to the difference in thermal conductivity between the thermal spray coating layers 13 and peeling of the first thermal spray coating layer 13.

(Fourth Embodiment) Next, a continuous casting mold D according to a fourth embodiment of the present invention will be described with reference to FIGS. The continuous casting mold D according to the present embodiment is different from the continuous casting mold A, as shown, in the inner upper portion 12c of each of the long pieces 30, 30a.
In addition, the surface hardness (about Hv100) of the base material 31 and the surface hardness (Hv6) of the first sprayed coating layers 13 and 14 are provided on the U-shaped portion 12d adjacent to the first sprayed coating layers 13 and 14.
00 surface hardness (Hv2 in this embodiment)
Thickness (t ₈ , t ₁₀ , t ₅ ) 0.1 to 0.1
The point is that 2 mm of Ni plating 32 was formed.
Note that, in the present embodiment, the vertical width (L
₇ ) is 1/10 to 3/10 of the vertical width (L ₂₀ ) of the inner upper portion 12c of each long piece 30, 30a, and the horizontal width (L ₉ ) of each Ni plating 32 is the inside of each long piece 30, 30a. It was 1 / 10-3 / 10 of the width of the upper 12c (L _22). Further, the short pieces are the same as the short pieces 23 and 23a of the continuous casting mold B, and thus the description thereof is omitted.

Next, a method of manufacturing the long piece 30 of the continuous casting mold D having the above-described configuration will be described with reference to FIG. First, both inner side portions 12a, the inner lower portion 12b, and the U-shaped portion 12d of the base material 31 are scraped off by about 0.1 to 2 mm with a plane grinding machine (not shown), and then the non-ground portion ( Ni plating is formed under the same plating conditions as described above so as to be flush with the upper part (inner side). And Ni plating 3 of both inner side parts 12a and inner lower part 12b
Similarly to the above, the boundary portion or the whole with 2 is ground about 0.1 to 2 mm from the surface by a surface grinder (not shown). As a result, a boundary surface between the Ni plating 32 and the thermal spray coating described later is formed. Next, after roughening the ground portion, similarly to the above, preferably a high-speed flame spraying machine 18 (see FIG. 4)
The first thermal spray coating layers 13 and 14 are formed under the same thermal spray conditions as described above so as to be flush with the inner upper portion 12c. And finally after spraying 12a, 12b, 12c,
The entire surface including 12d is ground and ground. In addition, long piece 3
Since the method of manufacturing Oa is the same as described above, the description is omitted.

As described above, according to the continuous casting mold D according to the present embodiment, the same effects as those of the first embodiment of the present invention can be obtained, and the inner upper portion 12c of the long pieces 30, 30a can be obtained.
And the U adjacent to the first sprayed coating layers 13 and 14
Since Ni plating 32 was formed on each of the letter-shaped portions 12d, hardening was performed from the inner upper part 12c of the long pieces 30, 30a to the inner lower part 12b, similarly to the second and third embodiments of the present invention. Generation of local wear due to the discontinuity of the thermal spraying, heat cracks due to the difference in thermal conductivity between the base material 31 and the first thermal spray coating layer 13, and peeling of the first thermal spray coating layer 13 can be prevented. Can be prevented.

(Fifth Embodiment) Next, FIGS.
A continuous casting mold E according to a fifth embodiment of the present invention will be described with reference to FIG. The continuous casting mold E according to the present embodiment is different from the continuous casting mold A as shown in FIG.
Thickness 2c entire (t _11, t ₅₎ Ni plating 36 so as to form respective 0.1 to 2 mm, the short side 37, 37
The thickness (t ₁₂ ) of the inner upper part 16b of the entire surface is 0.1 to 2 m.
This is a point that m Ni plating 39 was formed.

Next, a method of manufacturing the continuous casting mold E having the above-described configuration will be described with reference to FIGS. First, a method of manufacturing the long piece 34 will be described.
First, the entire inner surface of the base material 35 is scraped off by about 0.1 to 2 mm with a surface grinder (not shown), and the Ni plating with a thickness of about 0.1 to 2 mm Form plating. And both inner side portions 12
In the same manner as described above, the entirety of the boundary portion a and the inner lower portion 12b with the Ni plating 36 is ground about 0.1 to 2 mm from the surface by a surface grinder (not shown). This allows Ni
An interface between the plating 36 and the thermal spray coating described later is formed. Next, after roughening the ground portion, as described above,
Preferably, using a high-speed flame spraying machine 18 (see FIG. 4),
The first sprayed coating layers 13 and 14 are formed under the same spraying conditions as described above so as to be flush with the inner upper portion 12c. And
Finally, after the thermal spraying, the entire surface including 12a, 12b, and 12c is ground and ground.

When manufacturing the short piece 37, first,
The entire inner surface of the base material 38 is adjusted to about 0.
After shaving off by about 1 to 2 mm, Ni plating having a thickness of about 0.1 to 2 mm is formed on the portion 16b under the same plating conditions as described above. Then, the boundary portion or the entirety of the inner lower portion 16a with the Ni plating 39 is ground by about 0.1 to 2 mm from the surface by a surface grinder (not shown) in the same manner as described above.
As a result, a boundary surface between the Ni plating 39 and the thermal spray coating described later is formed. Next, after roughening this grinding part,
Similarly to the above, the second thermal spray coating layer 17 is formed under the same thermal spraying conditions as described above, preferably using a high-speed flame spraying machine 18 (see FIG. 4). Finally, after spraying, 16a, 1
The entire surface including 6b is ground. The long piece 34
a, the manufacturing method of the short piece 37a is the same as that described above, and the description is omitted.

As described above, according to the continuous casting mold E according to the present embodiment, the same effects as those of the first embodiment of the present invention can be obtained, and the inner upper portion 12 of the long pieces 34, 34a can be obtained.
c, and Ni platings 36 and 39 were formed on the inner upper portions 16b of the short pieces 37 and 37a, respectively.
5, 38 can be prevented from oxidizing and becoming brittle,
Further, the service life can be extended.

(Sixth Embodiment) Next, FIGS.
1, a continuous casting mold F according to a sixth embodiment of the present invention will be described with reference to FIG. As shown, the continuous casting mold F according to the present embodiment differs from the continuous casting mold A in that the Ni plating 42 (thickness (t ₁₃ , t ₁₄ ) 0.
1-2 mm) and Cr plating 43 (thickness (t ₁₅ ) 0.
02 to 0.1 mm), and each short piece 44, 4
Ni plating 46 (thickness (t)
₁₆ ) 0.1 to 2 mm) and Cr plating 47 (thickness (t
₁₇ ) 0.02 to 0.1 mm).

Next, a method of manufacturing the continuous casting mold F having the above-described configuration will be described with reference to FIGS. First, a method of manufacturing the long piece 40 will be described. First, the entire inner surface of the base material 41 is scraped off by about 0.1 to 2 mm with a surface grinder (not shown), and a Ni plating having a thickness of about 0.1 to 2 mm is formed on the portion 12c under the same plating conditions as described above. To form And both inner side portions 12
In the same manner as described above, the entirety of the boundary portion a and the inner lower portion 12b with the Ni plating 42 is ground about 0.1 to 2 mm from the surface by a surface grinder (not shown). This allows Ni
An interface between the plating 42 and the thermal spray coating described later is formed. Next, after roughening the ground portion, as described above,
Preferably, using a high-speed flame spraying machine 18 (see FIG. 4),
The first sprayed coating layers 13 and 14 are formed under the same spraying conditions as described above. After the thermal spraying, the entire surface including the Ni-plated surfaces 13, 14, and 12c is ground and ground. And finally, N
After the upper surface of the i-plate 42 is further finished, a Cr plating 43 is formed on the upper surface by a known method.

When manufacturing the short piece 44, first,
The entire inner surface of the base material 45 is adjusted to about 0.
After shaving off by about 1 to 2 mm, Ni plating having a thickness of about 0.1 to 2 mm is formed on the portion 16b under the same plating conditions as described above. Then, the boundary portion or the entirety of the inner lower portion 16a with the Ni plating is ground about 0.1 to 2 mm from the surface by a surface grinder (not shown) in the same manner as described above. As a result, a boundary surface between the Ni plating 46 and the thermal spray coating described later is formed. Next, after roughening the ground portion, similarly to the above, preferably using the high-speed flame spraying machine 18 (see FIG. 4) under the same spraying conditions as above, the second sprayed coating layer 17 is formed.
To form After the thermal spraying, the entire surface including the Ni-plated surfaces 17 and 16b is ground and ground. And finally, after further finishing the upper surface of the Ni plating 46,
Under the same plating conditions as above, a Cr plating 47 is formed.
In addition, the manufacturing method of the long piece 40a and the short piece 44a is the same as that described above, and the description is omitted.

As described above, according to the continuous casting mold F according to the present embodiment, the same effects as those of the first embodiment of the present invention can be obtained, and the long pieces 40, 40a and the short pieces 44, 4
Since the hard Cr plating 43, 47 is formed on the surface layer of the inner upper portions 12c, 16b of 4a, the abrasion resistance can be further improved as compared with the fifth embodiment of the present invention.

[0037]

Next, the results of a test for confirming the wear resistance of the continuous casting molds A to F according to the present embodiment will be described with reference to FIGS. (Examples 1 to 7, Comparative Examples 1 to 3) First, continuous casting molds A to F (Examples 1 to 6) shown in FIGS. 1 to 12 are prepared. At this time, the longitudinal width (L ₁ ) of the long piece and the short piece, the lateral width (L ₂ ) of the long piece, the lateral width (L ₃ ) of the short piece, and the maximum thickness (t ₁ , t ₂ ) of the long piece and the short piece are shown in Table 1, The radius of curvature (φ) of the inner surface of the long piece and both side surfaces of the short piece is 10500 as shown in Table 2.
mm.

The width (L ₄ ) of the long thermal spray coating layer 13, and the thickness of the lower end (t ₃ , t ₄ ), and
The vertical width (L ₅ ) of the first sprayed coating layer 14, the thickness of the lower end (t ₅ , t ₆ ), and the short sprayed second sprayed coating layer 1
7 of the longitudinal width (L _6), on which a uniform thickness over the lower end (t ₇₎ also, Table 1, were as shown in Table 2.

The chemical compositions of the first and second thermal spray coating layers 13, 14, 17 of the long piece and the short piece are as shown in Table 3.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

Also, in the continuous casting mold B (Example 2) shown in FIGS.
The vertical width (L ₇ ) of the i-plate 22 is 50 mm, and the thicknesses (t ₈ , t ₅ ) of the upper and lower ends thereof are 0.5 mm, 0.
5 mm (see Table 2), the vertical width (L ₈ ) of the Ni plating 25 of the short pieces 23 and 23a was 50 mm, and the uniform thickness (t ₉ ) was 0.5 mm over the upper and lower ends.

In the continuous casting mold C (Example 3) shown in FIGS. 1, 6, and 7, the N of the long pieces 26, 26a
The width (L ₉ ) of the i-plate 28 is 50 mm, and the thicknesses (t ₁₀ , t ₅ ) of the upper and lower ends thereof are 0.5 mm and 0.5 mm, respectively.
5 mm (see Table 2). The vertical width (L ₈ ) and the thickness (t ₉ ) of the Ni plating 25 of the short pieces 23 and 23a are as follows:
Similar to the above, they were 50 mm and 0.5 mm.

In the continuous casting mold D (Embodiment 4) shown in FIGS. 1, 6, and 8, the N
The vertical width (L ₇ ), the horizontal width (L ₉ ) of the i-plate 32,
The lower end thickness (t ₈ , t ₁₀ , t ₅ ) is 50 m as described above.
m, 50mm, 0.5mm, 0.5mm, 0.5mm
(See Table 2). In this case as well, the short pieces 23, 2
The vertical width (L ₈ ) and the thickness (t ₉ ) of the Ni plating 25 of 3a were set to 50 mm and 0.5 mm as described above.

Further, in the continuous casting mold E (Embodiment 5) shown in FIGS. 1, 9 and 10, the thickness (t ₁₁ , t ₅ ) of the upper and lower ends of the Ni plating 36 of the long pieces 34, 34a. Is 0.
5 mm, 0.5 mm (see Table 2)
The uniform thickness (t ₁₂ ) over the upper and lower ends of the Ni plating 39 of 7a was 0.5 mm.

Further, in the continuous casting mold F (Embodiment 6) shown in FIGS. 1, 11 and 12, the long pieces 40, 40a
On the Ni plating 42, the thickness of the lower end (t _13, t ₁₄₎ is
Each has a uniform thickness (t ₁₅ ) of 0.03 mm over the upper and lower ends of 0.3 mm, 0.5 mm, and Cr plating 43.
The uniform thickness (t ₁₆ ) of the short pieces 44 and 44a over the upper and lower ends of the Ni plating 46 is 1.0 mm, and the Cr plating 4
The uniform thickness (t ₁₇ ) over the upper and lower ends of 7 is 0.03 m
m.

The long piece 4 shown in FIGS.
A continuous casting mold (Example 7) having 0, 40a and short pieces 23, 23a was also prepared. At this time, on the Ni plating 42 of the long piece 40, 40a, the thickness of the lower end _{(t 13, t 14),} Cr
The thickness (t ₁₅ ) of the plating 43 is 0.3 m as described above.
m, 0.5 mm, and 0.03 mm.
The vertical width (L ₈ ) and thickness (t ₈ ) of the Ni plating 25 of 23a
₉ ) was set to 50 mm and 0.5 mm similarly to the above.

Further, as a comparative example, a long piece 5 shown in FIG.
0 and a short piece 52 (Comparative Example 1), a continuous casting mold having a long piece 55 and a short piece 60 shown in FIG. 14 (Comparative Example 2), and a long piece 65 and a short piece 67 shown in FIG. A casting mold for continuous casting (Comparative Example 3) was prepared.

The continuous casting mold (Comparative Example 1) shown in FIG.
To form a, obtained by forming a Ni plating 53 on the inner lower 52a of short piece 52, the dimensions of the long piece 50 and short strip _{52 (L 1 ~L 3, L} 5, L 6, t 1, t 2, t ₅ to
t ₇ ) was as shown in Tables 1 and 2. In addition, long piece 50
The radius of curvature (φ) of the inner surface and the both side surfaces of the short piece 52 was set to 10500 mm in the same manner as described above.

In the continuous casting mold (Comparative Example 2) shown in FIG. 14, a Ni-Co plating (Ni: Co = 1: 9) 56 is formed on an inner lower portion 55a of a long piece 55, and an inner upper portion thereof is formed. While Ni plating 57 and Cr plating 58 are laminated on 55b, Ni-Co plating (Ni: Co = 1: 9) 61 is formed on the inner lower part 60a of the short piece 60, and Ni plating 62 and Cr are formed on the inner upper part 60b. The plating 63 is laminated.

In this case, the thickness (t ₁₃ , t ₁₄ ) of the upper and lower ends of the Ni plating 57 of the long piece 55 and the Cr plating 58
The uniform thickness (t ₁₅ ) over the upper and lower edges is
0.3mm, 0.5mm, 0.03mm, and short piece 6
0 uniform thickness (t) over the upper and lower ends of the Ni plating 62
₁₆ ), uniform thickness over the upper and lower ends of the Cr plating 63 The thickness (t ₁₇ ) was 1.0 mm and 0.03 mm, respectively.

Also in this case, each dimension (L _{1 to} L ₃ , L ₅ , L ₆ , t ₁ , t ₂ , t ₅ to L _{5) of} the long piece 55 and the short piece 60 is also used.
t ₇ ) was as shown in Tables 1 and 2, and the radii of curvature (φ) of the inner surface of the long piece 55 and both side surfaces of the short piece 60 were also 10500 mm, similarly to the above.

In the continuous casting mold (Comparative Example 3) shown in FIG. 15, a self-fluxing alloy powder having a chemical composition shown in Table 3 is plasma-sprayed on an inner lower portion 65a of a long piece 65 to form a sprayed coating layer 6.
6 and the lower part 67a of the short piece 67
Is formed by spraying a self-fluxing alloy powder having the chemical composition shown in FIG.

In this case, too, the long piece 65 and the short piece 67
Of each dimension (L _{1 to} L ₃ , L ₅ , L ₆ , t ₁ , t ₂ , t ₅
To t ₇ ) are as shown in Tables 1 and 2, and the radii of curvature (φ) of the inner surface of the long piece 65 and both side surfaces of the short piece 67 are also 1 as described above.
It was set to 0500 mm.

Then, when each of the continuous casting molds A to F was mounted on an actual machine and used, as shown in Table 4, Comparative Example 1
Assuming that the lifetime was 1 (approximately 100 charges), in Comparative Examples 2 and 3, the lifetime could be extended somewhat, but in Examples 1 to 7
It was confirmed that the life could be extended much (about 3000 charges).

[0057]

[Table 4]

The embodiment of the present invention has been described above.
The present invention is not limited to the above-described embodiment, and all changes in conditions that do not depart from the gist are within the scope of the present invention. For example, in the first to sixth embodiments of the present invention, the molds A to F having variable widths have been described, but molds having a fixed width may be used. In this case, the first thermal spray coating layer may be provided on both inner side portions of the long piece with which each short piece contacts. Further, the first to sixth embodiments of the present invention are applied to a curved continuous casting machine, but may be applied to a vertical continuous casting machine. In this case, the inner surface of the long piece and both side surfaces of the short piece may be made flat. Further, in the first to sixth embodiments of the present invention, the molds A to F for continuously casting bloom have been described, but molds for continuously casting slabs may be used.
In this case, the size of the long piece or the short piece may be increased.

In the first to sixth embodiments of the present invention, the present invention is applied to a two-strand type continuous casting machine.
It may be applied to a continuous casting machine of a strand type, a three-strand type, or the like. In the second to sixth embodiments of the present invention, Ni plating 22, 25, 28, 32, 36,
Although 39, 42 and 46 are formed, a Ni alloy plating such as Ni-Co may be formed. In addition, the first to sixth aspects of the present invention
In the first embodiment, the thickness of the first sprayed coating layers 13 and 14 is gradually increased from the upper end to the lower end, but may be uniform from the upper end to the lower end. Conversely, the second thermal spray coating layer 1
7 may be gradually thickened from its upper end to its lower end.

[0060]

As is apparent from the above description, in the continuous casting mold according to the first to third aspects, the first and second inner side portions of the long piece and the inner lower portion of the short piece have the first, Second
Since the thermal spray coating layer is formed, the wear resistance to the slab shell (or slab, molten steel) can be improved, and a continuous casting mold having a long life can be provided. Especially,
In the continuous casting mold according to the second aspect, the hardness can be inclinedly changed from the upper end to the lower end of the long piece or the short piece, and peeling or local wear at an adjacent portion can be prevented. In the continuous casting mold according to the third aspect, oxidation of the base material can be prevented, and the life can be further extended.

[Brief description of the drawings]

FIG. 1 is a perspective view of a continuous casting mold according to first to third embodiments of the present invention.

FIG. 2 (a) is a perspective view of a long piece of a continuous casting mold according to the first embodiment of the present invention. (B) is FIG.
FIG. 4 is a sectional view taken along line WW of FIG.

FIG. 3A is a plan view of a short piece of the continuous casting mold. (B) is a front view of the short piece. (C) is FIG.
It is arrow XX sectional drawing of (b).

FIG. 4 is an explanatory diagram of a spraying state.

FIG. 5 (a) is a perspective view of a long piece of a continuous casting mold according to a second embodiment of the present invention. FIG. 5 (a) shows the state of FIG.
5 is a sectional view taken along the line QQ in FIG.

FIG. 6A is a plan view of a short piece of the continuous casting mold. (B) is a front view of the short piece. (C) is FIG.
It is arrow KK sectional drawing of (b).

FIG. 7A is a perspective view of a long piece of a continuous casting mold according to a third embodiment of the present invention. FIG. 7 (a)
It is RR sectional drawing of arrow. FIG. 8C is a sectional view taken along the line SS in FIG.

FIG. 8A is a perspective view of a long piece of a continuous casting mold according to a fourth embodiment of the present invention. FIG. 8 (a)
5 is a sectional view taken along the line YY in FIG. (C) is a sectional view taken along the line JJ in FIG. 8 (a).

FIG. 9 (a) is a perspective view of a long piece of a continuous casting mold according to a fifth embodiment of the present invention. FIG. 9B shows the state shown in FIG.
It is arrow NN sectional drawing of the arrow.

FIG. 10 (a) is a plan view of a short piece of the continuous casting mold. (B) is a front view of the short piece. (C) is FIG.
It is arrow PP sectional drawing of (b).

FIG. 11A is a perspective view of a long piece of a continuous casting mold according to a sixth embodiment of the present invention. (B) is FIG.
It is an arrow LL sectional view of (a).

FIG. 12A is a plan view of a short piece of the continuous casting mold. (B) is a front view of the short piece. (C) is FIG.
It is arrow MM sectional drawing of (b).

13A and 13B are perspective views of a long piece and a short piece of a comparative example of the continuous casting mold according to the first to sixth embodiments of the present invention, respectively.

FIGS. 14 (a) and (b) are perspective views of a long piece and a short piece of a comparative example of a continuous casting mold according to the first to sixth embodiments of the present invention, respectively.

FIGS. 15A and 15B are perspective views of a long piece and a short piece of a comparative example of the continuous casting mold according to the first to sixth embodiments of the present invention, respectively.

FIG. 16 is an explanatory view of a main part of a conventional curved continuous casting machine.

FIG. 17A is a perspective view of a continuous casting mold used in a conventional curved continuous casting machine. (B) is an exploded perspective view of the continuous casting mold.

FIGS. 18 (a) to (c) are enlarged perspective views of a main part of a defect near a meniscus of the continuous casting mold. (D)
FIG. 2 is a front view for explaining a problem of a long piece of the continuous casting mold. (E) is a main part perspective view of a defect near the meniscus of the continuous casting mold.

FIG. 19 (a) is an explanatory diagram of a defect of a long piece of the continuous casting mold. (B) is a sectional view taken along the line TT in FIG. 19 (a). (C) is explanatory drawing of the defect of the long piece of the casting mold for continuous casting. (D) is explanatory drawing of the defect of the same long piece.
(E) is a sectional view taken along the line U-U in FIG. 19 (d).

FIG. 20 is a perspective view of a long piece of a conventional continuous casting mold.

FIG. 21 (a) is a plan view of a short piece of a conventional continuous casting mold. (B) is a front view of the short piece. (C) is a sectional view taken along line VV in FIG. 21 (b).

[Explanation of symbols]

Reference Signs List A Continuous casting mold B Continuous casting mold C Continuous casting mold D Continuous casting mold E Continuous casting mold F Continuous casting mold 11 Long piece 11a Long piece 12 Base material 12a Inner side part 12b Inner lower part 12c Inner upper part 12d U-shaped part 12e Strip-shaped part 12f I-shaped part 13 First sprayed coating layer 14 First sprayed coating layer 15 Short piece 15a Short piece 16 Base material 16a Inner lower part 16b Inner upper part 16c Strip part 17 Second sprayed coating layer 18 High-speed flame spraying machine 20 Long piece 20a Long piece 21 Base material 22 Ni plating 23 Short piece 23a Short piece 24 Base material 25 Ni plating 26 Long piece 26a Long piece 27 Base material 28 Ni plating 30 Long piece 30a Long piece 31 Base material 32 Ni plating 34 Long piece 34a Long piece 35 Base material 36 Ni plating 37 Short piece 37a Short piece 38 Base material 39 Ni plating 40 Piece 40a length piece 41 preform 42 Ni plating 43 Cr plating 44 short pieces 44a short side 45 preform 46 Ni plating 47 Cr plating

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Masaharu Nozaki 1 Kimitsu, Kimitsu City, Chiba Prefecture Inside Nippon Steel Corporation (72) Inventor Kazuhiro Nibuya 21 Shinko Port, Kisarazu City, Chiba Prefecture Mishima Kosan Stock (72) Inventor Masaaki Tanabe 21st station, Shinko, Kisarazu-shi, Chiba Mishima Kosan Co., Ltd.Chiba branch office

Claims (3)

[Claims] 1. A continuous casting mold having a pair of long pieces and a pair of short pieces disposed between the pair of long pieces, wherein both short sides are in sliding contact with both inner sides of the long piece. The first part of the long piece that the solidified slab shell contacts with the solidified slab shell is formed with a first thermal spray coating layer of a self-fluxing alloy, and the inner lower part of the short piece that the slab shell touches. ,
A casting mold for continuous casting, wherein a second sprayed coating layer of a self-fluxing alloy is formed. 2. Ni is provided on an inner upper portion of the long piece at least in a portion adjacent to the first sprayed coating layer and on an inner upper portion of the short piece at least in a portion adjacent to the second sprayed coating layer. 2. The casting mold for continuous casting according to claim 1, wherein Ni plating is formed. 3. The continuous casting mold according to claim 1, wherein a Cr plating is formed on an inner upper surface of the long piece and on an inner upper surface of the short piece, respectively.