JPH07214117A - Rolling roll - Google Patents

Abstract

PURPOSE:To provide a rolling roll having a long life which is excellent in heat resistance, wear resistance and thermal shock resistance, has high strength and is not reacted with the metallic material to be worked such as iron and copper even at high temp. CONSTITUTION:The main body 5 of roll is a cylindrical body which consists of a ceramic sintered compact contg. by weight, >=60% Si3N4 of a main component and 0.1-20% of >=1 kind of Al2O3, MgO, Mg3N2, BeO, Be3N2, CaO, Ca3N2, FeO, WC, Mo2C. The rolling roll is provided with a driving shaft 8 which is inserted into the inside of this main body 5 of roll, tapered sleeve 9 which is forced into the annular clearance between the inside surface 5a of the main body of the rolling roll and the outside surface 8a of the driving shaft from the free end side of the main body 5 of roll, cross key 12 which is fit in the free end part of the main body 5 of roll respectively and one end part of the driving shaft 8 corresponding to the free end part and with which the main body 5 of roll is integrally revolved with the driving shaft 8 and fastening bolt 13 with which the forced state of the tapered sleeve 9 and the fit state of the cross key 12 are kept by being fastened on one end part of the driving shaft 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling roll used for hot rolling metal wires such as copper and copper alloys, iron and iron alloys.

[0002]

2. Description of the Related Art Conventionally, a continuous casting and rolling system in which a casting machine and a rolling machine are directly connected to each other has been mainly adopted as a production system for metal wire rods, particularly copper wire rods.

Generally, as a method of holding a rolling roll, there are a double-sided holding method shown in FIG. First, in the double-supported type of FIG. 4, the shaft portions 1, 1 of the roll A and the body portion 2 are integrated, and both shaft portions 1, 1 receive a rotational force from a drive motor (not shown) to cause the body portion 2 to rotate. The wire rod 4 is rolled by the caliber 3 formed in 1.

In the roll A, the body 2 to be rolled has a high hardness in order to have wear resistance and heat resistance, for example, a Shore hardness of 60 to 70. On the other hand, since the shaft portions 1 and 1 are driving force transmitting portions, it is necessary to have a toughness with a low hardness, for example, a Shore hardness of about 40 to 50 in consideration of embrittlement at a high temperature. Therefore, it is difficult to apply the ceramics roll with this double-sided type. However, it is applicable if only the processed groove portion, that is, only the caliber 3 portion is formed from the ceramics of the present invention, and is fitted into the body portion.

On the other hand, as shown in FIG. 5, a rolling roll used in a cantilever type rolling mill has a ring-shaped roll 5 on which a caliber 6 and a key hole 7 are formed. By adopting such a cantilever type basic roll structure, as shown in FIG.
As shown in FIG. 3, since the roll is composed of only the body portion and the driving force is transmitted to the inner surface of the roll under the condition that the sleeve 9 uniformly applies the internal pressure, the toughness of metal is not necessary.
Accidents such as breakage will not occur. In addition, the roll volume is small, manufacturing is easy, and especially when using expensive ceramics, the cantilever type is much more economical. On the other hand, the material of the roll has the following conventional background.

Conventionally, tool steel has been exclusively used as a material for hot rolling rolls of copper and copper alloy wire rods. This tool steel uses carbon steel with alloy elements such as Cr, Mo, V, W, and Mn in consideration of the alloy ratio, and by further optimizing heat treatment conditions such as quenching and tempering, the strength at high temperature is improved. , Hardness, toughness, wear resistance, etc. have been improved.

However, as described above, for example, in the rolling of copper wire, the rolling temperature is as high as 500 to 1000 ° C., and the strong working of reducing the surface area to 60% is performed at high speed. Limit temperature 300 ℃
However, even with various improvements, there was a limit in extending the life of the roll.

That is, due to the microscopic non-uniformity of the structure of the roll surface and the fluctuation of processing conditions, local cracks are generated on the roll surface at around 900 ° C., and the iron pieces peel off.
At around 00 ° C., the film is locally worn to generate linear scratches and roughens the roll surface.

As a result, the iron powder may be mixed into the steel wire and the wire may be broken in the drawing process, and the surface of the roll is roughened due to the rough surface of the roll, which leads to the deterioration of the quality of the wire. For this reason, the service life of a normal roll is as short as 5 to 8 hours, and it is necessary to stop the line and replace it with a new roll. This roll exchange requires 0.5 to 1 hour, during which the continuous casting and rolling line must be stopped. Thus, in the production of wire rods, roll defects are the biggest factor in forcing the rolling line to stop.

In addition, there is also a problem that a portion separated due to wear of the roll or generation of cracks is press-fitted into the wire material to cause foreign matter disconnection during wire drawing of the wire material.

Therefore, from the viewpoint of improving the wear resistance, the use of a high hardness cemented carbide roll has also been investigated. As a general cemented carbide, there is a WC-Co system, but such cemented carbide exhibits excellent wear resistance in cold working and is widely used for rolls, dies and the like. However, in hot rolling rolls, copper and binder C
O reacts and the reaction product is fragile and falls off to generate particle drop holes on the roll surface, which rather reduces the roll life.

[0012] Cr ₇ to this reason, mainly of Stellite (Cr ₇ C ₃₎ as a lower cemented carbide reactivity with copper
Improvement of Carbide roll by varying the various alloying components, such as C ₃ -Ni-W system was performed.

However, even in this case, although the reactivity with copper is slightly reduced and improved, the alloy components become brittle due to oxidation at high temperatures, resulting in a markedly rough surface of the roll and a wear resistance. It was not so much improved, and therefore was ineffective in improving the life. It is ceramics that have low reactivity with copper at high temperatures, and those containing Al ₂ O ₃ or ZrO ₂ as the main component have been investigated, and it is generally considered to use alumina-based ceramics containing Al ₂ O ₃ as the main component. Has been. However, since this alumina-based ceramic has low strength and toughness, it has a drawback in that it is easily broken under conditions of high stress and high impact, such as the rolling roll shown in FIG. 4, and cannot be used.

The present invention has been made in order to solve the above-mentioned conventional problems, and is excellent in heat resistance, wear resistance and thermal shock resistance, has high strength, and is capable of working with a metal work material such as copper iron and hot work. However, the object is to provide a long-life rolling roll that does not react. Here, hot means a temperature of 300 ° C. or higher.

[0015]

Means for Solving the Problems The present inventors have earnestly studied and, as a hot rolling roll for metal wire rods such as copper and copper alloys, iron and iron alloys, the following characteristics are required. It was confirmed.

That is, (1) it does not react with a metal workpiece such as copper at high temperature, (2) its strength does not decrease at high temperature,
(3) High wear resistance at high temperature, uniform even if wear occurs (scratch resistance), (4) Small thermal expansion coefficient and strong against heat shock.

The inventors of the present invention have conducted various studies on ceramics such as ZrO ₂ system and Si ₃ N ₄ system as raw materials for hot rolling rolls satisfying all of these characteristics, and as a result, silicon nitride (Si ₃ N ₄ ) It has been found that a particular composition of ceramics is most suitable. That is,
(1) Low reactivity with wire material such as copper, 1100 ℃
Does not react with copper at all. Therefore, the maximum rolling temperature for copper is 1.
Since it is about 000 ° C, there is no problem at all. The same points have been confirmed for steel and aluminum materials. (2)
The hot strength is high and hardly decreases up to 1000 ° C. (3) High wear resistance. Si ₃ N ₄ has a higher hardness than a super hard roll and has a unique property that it exhibits lubricity at high temperatures, and therefore has high wear resistance at high temperatures. (4) The coefficient of thermal expansion is as small as 3.2 × 10 ⁻⁶ / ° C., which is about 15 × 10 of the Ni—Co—Fe alloy known as a low expansion coefficient alloy.
It is about ⅕ of ^-6 (at 350 ° C or higher).

Further, since the rolling roll is used under the condition of heat cycle in which it is heated to a high temperature by the wire and cooled by cooling water, the smaller the expansion coefficient is, the more advantageous it is. In addition, the specific gravity is 3.2, which is less than half the weight of tool steel, so the burden on the worker for roll replacement work is reduced.

As described above, it is recognized that the ceramics roll containing Si ₃ N ₄ as the main component is excellent as a rolling roll for metals such as copper and copper alloys, iron and iron alloys. The present inventors were further faced with the purpose of significantly extending the life of the Si ₃ N ₄ ceramics roll, and used a Si ₃ N ₄ ceramics having a specific composition and excellent metal durability at high temperature as described later. Moreover, the excellent properties of the Si ₃ N ₄ ceramics were fully utilized by using the roll having the structure described below, and the desired properties could be obtained by their synergistic effect.

In fact, when the ceramics of the present invention containing Si ₃ N ₄ as a main component is set and used by the roll system having the structure of the present invention in the final stand of a rolling mill of a wire rod continuous casting and rolling line, it is used for 100 hours or more. However, the present invention has been completed by finding that there is no abnormality on the surface of the wire such as rough skin and abrasion of the wire, and that it has a life of 10 times or more that of the conventional tool steel roll.

That is, the present invention is a rolling roll used for hot rolling a metal wire rod, wherein the roll body is a cylindrical body made of ceramics as described above, and the drive shaft is provided inside the roll body. Through the free end side of the roll body, the tapered sleeve is press-fitted into the annular gap between the inner surface of the rolling roll body and the outer surface of the drive shaft, and the free end portion of the roll body and the corresponding drive shaft Fit the crosskey to one end (depending on the case,
2a and the hole 7 of the roll body may be removed) The roll body is compressed and fixed from the direction of its free end so as to rotate integrally with the drive shaft, and a fastening bolt fastened to one end of the drive shaft is provided. By using this, the press-fit state of the taper sleeve and the fitted state of the cross key are maintained.

According to the roll structure of the present invention, the shaft portion is not integrally formed with the cylindrical roll body (body) made of ceramics, but instead the drive shaft is inserted into the inside of the roll body and the taper sleeve is provided. Since the cross key is press-fitted between the roll body and the drive shaft and the cross keys are fitted to the respective ends of the roll body and the drive shaft, the roll body is driven from the inner surface of the roll via the taper sleeve to rotate the drive shaft. However, mainly by the pressure load from the roll free end surface by the cross key, the roll main body is fixed and rotates integrally with the drive shaft. Here, the driving force of the driving shaft is transmitted to the outer surface of the roll by the lateral pressure of the cross key while the weak inner pressure is additionally and uniformly applied to the inner surface of the roll by the taper sleeve. Toughness and strength are not required. Therefore, since it becomes possible to use ceramics having particularly excellent heat resistance as the roll material, there is no possibility that the roll will be broken or the like.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a rolling roll according to the present invention. In the figure, a cantilever type rolling roll of the present invention used for hot rolling a metal wire rod has a roll body 5, a drive shaft 8, a taper sleeve 9, a cross key 12, and a fastening bolt 13. And is characterized by the following mounting structure.

First, the roll main body 5 is a cylindrical body having an outer peripheral surface provided with a caliber 6, the inner end of which is supported by the machine body 21 through the turntable 20, and the outer end of which is a cloth to be described later. A key hole 7 (see FIG. 3) into which the key 12 fits is formed. As the roll material, Si ₃ N ₄ ceramics having a specific composition described later is used.

A drive shaft 8 which receives a rotational force from a drive motor (not shown) is inserted into the inside of the roll body 5. As shown in FIG. 2, a pair of semi-cracked roll shafts 14 are integrally formed at the free end of the drive shaft 8. As shown in FIG. 1, the fixing nut 2 is attached to the roll shaft 14.
3 is fixed by a screw 24, and the fastening bolt 13 is screwed into the fixing nut 23.

On the other hand, the taper portion 9a of the taper sleeve 9 is pressed into the annular gap between the inner surface 5a of the roll body 5 and the outer surface 8a of the drive shaft 8 from the free end side of the roll body 5. Also, the head portion 9 of the taper sleeve 9
A through hole 9c through which the fastening bolt 13 penetrates and a bolt receiving portion 9d are provided in b, and the fastening state of the taper sleeve 9 is maintained by tightening the fastening bolt 13.
10 is a nut and 11 is a lock nut.

Further, on the side surface of the taper sleeve 9,
Through holes 9e, 9e through which the cross key 12 penetrates are formed. The cross key 12 has a central portion between the roll shafts 14,
It is designed such that the roll main body is compressed between the free end portion and the projection portion 12 at both ends.
a is fitted in the key holes 7, 7 of the roll body 5. As a result, the roll body 5 is integrally rotated with the drive shaft 8. Further, the tip end portion of the fastening bolt 13 presses the cross key 12 toward the drive shaft 8 side, whereby the fitted state of the cross key 12 and the roll main body 5 is maintained.

As described above, the first feature of the cantilever type rolling roll according to the present invention is, as shown in FIG. 1, that the cantilever type rolling roll has a simple structure that makes use of the basic structure of the cantilever type. The shaft portion (corresponding to reference numeral 1 in FIG. 4) is not integrally formed with the cylindrical roll body 5 (body portion), but instead, the drive shaft 8 is inserted into the inside of the roll body 5 and the taper sleeve 9 is rolled. The point is that it is press-fitted between the main body 5 and the drive shaft 8 and the cross keys 12 are fitted to the respective ends of the roll main body 5 and the drive shaft 8. As a result, the roll body 5 has the inner surface 5 of the roll.
The rotational drive force of the drive shaft 8 is received from the a via the taper sleeve 9, and the roll key 5 is moved by the cross key 12.
Pressure is applied to the free end surface of the roll main body 5 so that the roll main body 5 is fixed on the same surface, and the roll main body 5 rotates integrally with the drive shaft 8. Here, since the driving force of the drive shaft 8 is transmitted to the inner surface 5a of the roll in a state where a weak inner pressure is uniformly applied by the taper sleeve 9, the roll main body 5 is not required to have the toughness, strength and the like of metal. Therefore, in the ceramic roll of the present invention, the use of ceramics having particularly excellent heat resistance as described below as a roll material prevents the occurrence of accidents such as cracking by the above structure. It has become possible to achieve a significantly longer life.

Next, a second feature of the present invention is that the roll body 5 is made of a ceramic having a specific composition. In particular, non-oxide type Si ₃ N ₄ ceramics is used as the ceramics. Here, Si ₃ N ₄ ceramic to be used as a roll material in the present invention, used as the Si ₃ N ₄ to 60 wt% or more main component as a raw material powder, this AlN, Al
₂ O ₃ , Y ₂ O ₃ , YN, MgO, CaO, ZrO ₂ , Ti
O ₂ , HfO ₂ , WC, Mo ₂ C, SiC, CeO ₂ , Be
It is a mixture of additives such as O, TiN, Be ₃ N ₂ and Al as a sintering aid.

The reason why the Si ₃ N ₄ powder content is 60% by weight or more is that if the content is less than 60%, the strength becomes brittle and the impact resistance decreases.

An example of the combination of additives used for 60 wt% or more of Si ₃ N _{4 is as} follows.
Al ₂ O ₃ , MgO, Mg ₃ N ₂ , BeO, B with respect to ₃ N ₄ .
_{e 3 N 2, CaO, Ca} 3 N 2, FeO, WC, ceramic sintered bodies containing 0.1 to 20% by weight of one or two or more of Mo ₂ C, especially the use of 900 ° C. or less Even under the conditions, there is little deterioration in strength, hardness, etc. Therefore, it is effective as a rolling roll for copper used under such conditions.

Further, the powder of oxide, carbide, nitride, boride or silicide of the group IIIB element of the periodic system such as Y ₂ O ₃ and YN with respect to Si ₃ N ₄ is 0.1 to 25% by weight. Al
A ceramics sintered body containing 0.1 to 25% by weight of ₂ O ₃ , AlN, and Al is suitable for a rolling roll used under conditions of 1100 ° C. or lower.

Further, for Si ₃ N ₄ , AlN, Zr
A ceramic sintered body containing 1 to 20% by weight of one or more kinds of O ₂ , TiO ₂ , HfO ₂ , SiC, CeO ₂ , and TiN is effective for a rolling roll used under a condition of 800 ° C. or lower.

As a method for producing such Si ₃ N ₄ ceramics, a known atmospheric pressure sintering method, HIP method, hot pressing method or the like may be used.

Moreover, in this embodiment, since the rolling roll used for hot rolling is only the roll body (body) and the shaft is not integrally formed, the roll volume is small and the manufacturing is easy as described above. In addition, the material cost of expensive Si ₃ N ₄ can be small, so that the cost is much lower than that of the double-support type and it is economical.

Here, hot rolling means 300 as described above.
Although it indicates a temperature of ℃ or more, even in cold working, the wear resistance of Si ₃ N ₄ is superior to that of tool steel. However, the difference in life is greater at higher temperatures, that is, ceramics have a longer life and are more cost effective, so they are limited to hot use. In the roll of the present invention, as described above,
It is advantageous when the material to be rolled is hot worked at a temperature of 00 to 1000 ° C., but particularly when the material to be rolled is a wire, by cooling the roll with cooling water having a flow rate of 0.4 m ³ / hr or more. , Stable rolling at a feed speed of 1 m / sec or more is possible.

As described above, the Si ₃ N ₄ ceramics roll of the present invention has higher quality and longer life than the conventional roll, and has excellent performances such as improvement of the operation rate of the continuous casting and rolling line and improvement of the quality of the manufactured wire rod. It turned out to have.

An experimental example of the present invention will be described below.

(Experimental Example 1) In a continuous casting and rolling line for producing a copper wire containing 0.3% Sn, a conventional tool steel roll, a cemented carbide roll, and Si ₃ were used as the rolling rolls of the final stand.
N ₄ -Y ₂ O ₃ based ceramics roll and Si ₃ N of the present invention
₄ Ceramics roll (AlN 1.5% by weight-Al ₂ O ₃
4.0 wt% -Y ₂ O ₃ 3.0 wt% -Si ₃ N ₄ 9
1.5% by weight) for comparison. The rolling roll is a cantilever holding type rolling mill of FIG. 1 in which a ring-shaped rolling roll is fitted into a tapered sleeve. Casting machine temperature is 70
The surface reduction rate was 0 ° C. and 20%.

The results are shown in Table 1. Both conventional tool steel rolls and cemented carbide rolls were worn for 5 to 6 hours, surface scratches and spot peeling occurred, the surface of the wire was roughened, and the quality was deteriorated. Was not escaped. Further, in the conventional Si ₃ N ₄ —Y ₂ O ₃ based ceramic roll, the fracture of the wear was observed on the roll surface after rolling for 50 hours.

On the other hand, in the Si ₃ N ₄ ceramics roll of the present invention, the surface of the roll was not roughened or worn even after being rolled for 100 hours, and the surface of the rolled wire was smooth. The roll was usable even after 100 hours.

[0043]

[Table 1]

(Embodiment 2) By the setting method of FIG. 1 which is the same as the embodiment 1, and by the setting method of FIG. 6 for comparison separately,
A rolling experiment was conducted under the same other conditions. Ten roll materials were used in the experiment. Table 2 shows the difference between the set methods of FIG. 1 and FIG.

[0045]

[Table 2]

The results of the experiment are shown in Table 3. As is clear from this result, in the set method shown in FIG. 6, the tensile stress in the radial direction on the inner surface of the roll becomes large, and although there is no fracture in tool steel and cemented carbide with high toughness, the conventional Si ₃ N ₄ − Y ₂
With O ₃ system ceramics, half of them have already been broken in 30 hours, and the ceramics of the present invention of the same set method have 100% damage.
Although it could be used for an hour, it still suffered a breakage with 10%.

When the set method is compared with the product of the present invention, the method of FIG. 1 does not cause any cracking, and the method of FIG. 1 is most effective for prolonging the roll life and maintaining the quality of the wire. all right.

[0048]

[Table 3]

(Experimental Example 3) In a continuous casting and rolling line
When manufacturing tough pitch copper wires,
Conventional tool steel rolls, carbide rolls, Si₃N_Four
-Y₂O₃-Based ceramics roll and Si of the present invention₃N_FourSE
Ramix Roll (AlN 3 wt% -Al₂O₃  6 weight
% -Y₂O₃ 4 wt% -Si₃N_Four 87% by weight)
As in Example 1, the roll characteristics are compared by the set method of FIG.
Compared.

The wire temperature was 950 ° C. and the area reduction rate was 50%. As is clear from Table 4, in all the conventional rolls, after 7 to 8 hours of use, surface roughness and cracks were generated on the roll surface, and foreign matter of the roll material was mixed into the wire to cause disconnection. Occurred. Further, the conventional Si ₃ N ₄ -Y ₂ O ₃
In the ceramic ceramic roll, wear damage was observed on the roll surface after rolling for 80 hours.

On the other hand, the Si ₃ N ₄ ceramics roll according to the present invention has a long life in which there is no abnormality in the roll even after 200 hours of use. Was given.

[0052]

[Table 4]

(Experimental Example 4) In a rolling line for producing aluminum wire, a conventional tool steel roll, a cemented carbide roll, and a conventional Si ₃ N ₄ -Y ₂ were used as the rolling rolls of the final stand.
A comparison was made between an O ₃ -based ceramic roll and the Si ₃ N ₄ ceramic roll of the present invention (Si ₃ N ₄ 90 wt% -Al ₂ O ₃ 5 wt% -MgO 5 wt%). The rolling roll is a cantilever holding type rolling mill of FIG. 1 in which a ring-shaped rolling roll is fitted into a tapered sleeve. The casting machine temperature was 500 ° C., and the area reduction rate was 20%.

The results are shown in Table 5. Both conventional tool steel rolls and cemented carbide rolls wear in 4 to 7 hours, surface scratches and overall wear occur, the surface of the wire rod becomes rough, and the quality is not deteriorated. I could not escape. Further, in the conventional Si ₃ N ₄ —Y ₂ O ₃ system ceramic roll, abrasion damage was found on the roll surface after rolling for 68 hours.

On the other hand, in the Si ₃ N ₄ ceramics roll of the present invention, the surface of the roll was not roughened or worn even after being rolled for 140 hours, and the surface of the rolled wire was smooth.

[0056]

[Table 5]

(Experimental Example 5) In a continuous casting and rolling line for producing iron wire, a conventional tool steel roll, a cemented carbide roll, and a conventional Si ₃ N ₄ -Y ₂ were used as the rolling rolls of the final stand.
O ₃ type ceramics roll and Si ₃ N ₄ ceramics roll of the present invention (Si ₃ N ₄ 93 wt% -AlN 3 wt%
-CeO2 ₂ wt% -TiN 2 wt%) for comparison. The rolling roll is a cantilever holding type rolling machine in which a ring-shaped rolling roll is fitted into a taper sleeve. The casting machine temperature was 800 ° C., and the area reduction rate was 15%.

The results are shown in Table 6. Both conventional tool steel rolls and cemented carbide rolls were worn in 5 to 9 hours, scratches and point-like peeling occurred on the roll surface, and the wire surface was markedly rough. It was Further, in the conventional Si ₃ N ₄ —Y ₂ O ₃ system ceramic roll, abrasion damage was observed on the roll surface after 90 hours of rolling.

On the other hand, in the Si ₃ N ₄ ceramics roll of the present invention, the surface of the roll was not roughened or worn even after rolling for 270 hours, and the surface of the rolled wire was smooth. Further, the roll was usable even after 270 hours.

[0060]

[Table 6]

[0061]

As described above, according to the present invention, the taper sleeve is press-fitted between the ceramic roll body and the drive shaft, and the cross keys are provided at the free ends of the roll body and the drive shaft. Since it is a rolling roll to be fitted, the roll body does not need toughness, strength and the like of metal. In addition to this, since Si ₃ N ₄ with a specific composition and excellent metal durability at high temperature is used as a roll material, the synergistic effect is excellent heat resistance, wear resistance, and impact resistance that have never been seen before. It is possible to obtain a rolling roll that has high strength and has a much longer life that does not react with a metal workpiece such as copper even at a high temperature, and as a result, it is possible to perform stable and highly efficient rolling. is there.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a state where a ceramic rolling roll according to the present invention is attached to a cantilever rolling mill.

FIG. 2 is an exploded perspective view of a rolling roll.

FIG. 3 is a perspective view of a roll body.

FIG. 4 is a side view of a conventional double-sided rolling roll.

5A is a front view of a cantilever type rolling roll, and FIG. 5B is a side view of the same.

6 is a vertical cross-sectional view showing another example of a state in which the ceramic rolling roll shown in FIG. 1 is attached to a cantilever rolling mill.

[Explanation of symbols]

 5 Roll main body 8 Drive shaft 9 Taper sleeve 12 Cross key 13 Fastening bolt

Continued Front Page (72) Inventor Matsuo Higuchi 1-1-1 Kunyo Kita, Itami City, Hyogo Prefecture Sumitomo Electric Industries, Ltd. Itami Works (72) Inventor Eiji Kamijo 1-1-1 Kunyo Kita, Itami City, Hyogo Prefecture Sumitomo Electric Industries, Ltd. Itami Works

Claims (3)

[Claims] 1. A rolling roll used for hot-rolling a metal wire rod, which contains 60 wt% of Si ₃ N ₄ as a main component.
Above, Al ₂ O ₃ , MgO, Mg ₃ N ₂ , BeO, Be
_A cylindrical roll body made of a ceramics sintered body containing 0.1 to 20% by weight of one or more of ₃ N ₂ , CaO, Ca ₃ N ₂ , FeO, WC and Mo ₂ C. A drive shaft inserted into the roll body, a taper sleeve press-fitted into the annular gap between the inner surface of the rolling roll body and the outer surface of the drive shaft from the free end side of the roll body, and the play of the roll body. One end of the drive shaft, and a cross key that is fitted to the end and one end of the drive shaft corresponding thereto and that compresses and fixes the roll main body from its free end direction to rotate the roll main body integrally with the drive shaft. A rolling roll, comprising: a fastening bolt which is fastened to hold the press-fitted state of the tapered sleeve and the fitted state of the cross key. 2. The roll main body according to claim 1
Si₃N_Four 60% by weight or more, Y₂O₃, YN and other elements
Periodic Group IIIB element oxides, carbides, nitrides, borides
Or 0.1 to 25% by weight of one or more of silicides
And Al₂O₃, AlN, one or more of 0.1 to 0.1
Characterized in that it is a ceramics sintered body containing 25% by weight
A rolling roll to do. 3. The roll main body according to claim 1
Si₃N_Four 60% by weight or more, AlN, ZrO₂, Ti
O₂, HfO₂, SiC, CeO₂, One of TiN
A ceramic sintered body containing 1 to 20% by weight of the above
A rolling roll characterized in that