JP2001105008A - Built-up rolling roll using sintered hard alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a built-up rolling roll in which a complex sleeve made by metallically joining the outer layer of a sintered hard alloy and inner layer-of steel is fit and fixed on a shaft part and which is suitable for rolling a metal plate having a wide rolling part. SOLUTION: This roll is the built-up rolling roll using the sintered hart alloy in which a barrel part consisting of the complex sleeve 2 made by metallically joining the outer layer 3 of the sintered hard alloy and inner layer 4 of steel is fit on the outer periphery of the shaft part 1, an interior hole 5 which is coaxial with the axis of rotation is provided in an approximate position of the interior of the shaft part corresponding to the width of the rolling part in the direction of the axis of rotation of the barrel part, and a cooling medium is supplied (A) into the interior hole through a through hole 6 which is coaxial with the axis of rotation and communication to the interior hole from the end face of the shaft part and also discharged (B).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembling type roll in which a composite sleeve in which an outer layer of a cemented carbide and an inner layer of a steel material are metallically joined is fitted and fixed to a shaft, and in particular, a sheet material having a wide rolled portion. And a roll suitable for rolling.

[0002]

2. Description of the Related Art A sleeve made of a cemented carbide alone has been used for a long time in fields such as wire rod, bar and steel tube rolling by a special rolling mill such as a block mill. In recent years, various attempts have been made to apply cemented carbides to rolling mills for general wire rods, steel bars, flat bars, and the like, and they have been put to practical use in some applications and have exhibited excellent wear resistance.

For example, a cemented carbide having excellent wear resistance is used as an outer layer, and a steel material having excellent toughness is used as an inner layer, and both are sintered by hot isostatic pressing (hereinafter abbreviated as "HIP"). At the same time, there is an assembling type roll using a diffusion-bonded composite material structure sleeve. As an example, JP-A-10-8211
Japanese Patent Application Laid-Open No. H11-163,837 discloses a roll-type roll in which a composite sleeve in which an outer layer of various high-speed steels or cemented carbides is provided on the outer periphery of an inner layer made of cast steel or forged steel or graphite cast steel is fitted and fixed to a shaft portion. It is said that by forming the end portion in a specific shape described in the publication, breakage of the body end portion can be prevented even when subjected to rolling.

[0004] In the rolling roll, the temperature of the roll increases due to the heat of the plastic working by rolling, the frictional heat, the heat of the rolled material heated and heated, etc., being transmitted to the roll. In particular, when the width of the rolled portion is wide as in the case of plate rolling, the temperature of the roll at a position corresponding to the width of the rolled portion increases. In order to prevent the temperature of the roll from rising, the roll is generally cooled by spraying high-pressure cooling water onto the surface of the roll. This cooling suppresses a rise in the temperature of the roll, but the temperature distribution in the direction of the rotation axis of the roll is not uniform, and the temperature at a position corresponding to the width of the rolled portion increases. The body end that does not come into contact with the rolled material is effectively cooled from the surface, has no direct heat transfer from the rolled material, and has heat diffusion to the axle side, so that the temperature rise is small. If the temperature distribution in the rotation axis direction is non-uniform, the diameter of the roll becomes non-uniform due to thermal expansion, and the position corresponding to the width of the high-temperature rolled portion expands.

In order to control the shape to be deformed in this way,
Various means for providing a hollow hole coaxially with the rotation axis inside the roll and cooling the inside of the roll with cooling water are disclosed. For example, Japanese Utility Model Laid-Open No. 57-127302 discloses that a guide for changing a flow path is inserted into a cooling water guide hole sufficiently smaller than a roll diameter formed in the axial direction of a work roll for cold rolling. Further, a work roll for cold rolling that performs thermal crown control is disclosed. It is said that the guide causes a simple flow of the cooling water in the flow path to be in a turbulent state, thereby performing highly efficient cooling.

In summary, Japanese Utility Model Laid-Open Publication No. 3-57405 discloses that, in summary, a cylindrical hollow portion is formed along the axis of a roll main body from the shaft end on the non-drive side to below the barrel end on the drive side. A fixed pipe whose both ends are opened with a gap in the barrel area inside the hollow part is provided, and a movable pipe that can reciprocate in the axial direction is inserted through the non-drive side of the fixed pipe, and the position of the movable pipe is controlled. There is disclosed a cooling structure of a work roll for rolling which equalizes internal water cooling in an axial direction of a main body.

[0007]

Rolling rolls suffer from less wear and roughening due to rolling, and are less susceptible to heat cycling in which the heating during rolling affects the rolls, and rolling defects such as biting (stop rolling). It is required to have a strength against the resulting thermal crack. For rolls using cemented carbide,
It is desired to provide a roll that has improved its weak point, that is, heat crack resistance, by utilizing its excellent abrasion resistance and skin abrasion resistance. As an example of this, as in the above paragraph number 0003, an assembling rolling roll in which a composite sleeve made of a steel material is used as an inner layer, a compressive residual stress is applied to an outer layer of a cemented carbide, and the shaft is fitted and fixed to a shaft portion has been proposed. I have.

[0008] Even in the assembling type roll using a cemented carbide, there is a problem that the roll shape is deformed due to thermal expansion accompanying the rise in the roll temperature, as described in paragraph 0004. Another major problem is that cracks are likely to occur in the outer layer of the cemented carbide. Alternatively, a crack is generated and propagated to break the roll. That is, the coefficient of thermal expansion of a cemented carbide containing about 80% by weight of WC is approximately 7 × 10 ⁻⁶ / ° C.
The coefficient of thermal expansion of steel is approximately 12 × 10 ⁻⁶ / ° C., but due to this large difference in coefficient of thermal expansion, the inner layer and the shaft of the steel expand more as the roll temperature increases during rolling. Tensile stress acts on the outer layer of the hard alloy. Then, the compression stress applied to the bending angle is canceled out, so that a crack is easily generated. Alternatively, the tensile stress becomes excessive and a crack is generated to cause breakage. This tendency is particularly remarkable in the case of rolling a sheet material having a wide rolling portion, where the temperature tends to rise. The present invention
An object of the present invention is to solve these problems and to provide an assembling type roll using a cemented carbide that can be used safely.

[0009]

According to a first aspect of the present invention, a body made of a composite sleeve in which an outer layer of a cemented carbide and an inner layer of a steel material are metallically joined to the outer periphery of a shaft, An internal hole coaxial with the rotating shaft is provided at an approximate position inside the shaft portion corresponding to the width of the rolling portion in the direction of the rotating axis of the body, and a through hole is formed coaxially with the rotating shaft and passes from the end face of the shaft portion to the internal hole. This is an assembling type roll using a cemented carbide that supplies and discharges a coolant to the holes.

According to a second aspect of the present invention, a concave portion is provided along the circumferential direction on the inner periphery of the internal hole of the shaft portion corresponding to the central portion in the rotation axis direction of the body portion of the assembling roll of the first invention. It is an assembly type rolling roll using a cemented carbide.

According to a third aspect of the present invention, when the composite sleeve is fitted to the outer periphery of the shaft of the assembling roll of the first invention or the second invention, the contact between the outer peripheral surface of the shaft and the inner peripheral surface of the composite sleeve is established. To
The approximate portion corresponding to the width of the rolled portion is in metal contact, and the approximate portion corresponding to the remaining barrel end is an assembling roll using a cemented carbide in adiabatic contact.

According to a fourth aspect of the present invention, in order to supply the refrigerant to the internal hole of the assembled rolling roll according to the first to third aspects of the present invention, the supply pipe inserted into the internal hole through the through hole extends from the side surface to the internal surface of the internal hole. It is an assembly-type rolling roll using a cemented carbide using a supply pipe that injects a refrigerant toward the roll.

FIG. 1 shows a first invention, a third invention, and a fourth invention of the present invention.
It is sectional drawing of the rotation axis direction of an Example of invention. FIG. 2 is a sectional view of the first, second, and third embodiments of the present invention taken along the rotation axis. Below these figures, the positional relationship of the roll body in the rotation axis direction is additionally shown. The assembly type rolling roll using the cemented carbide of the present invention fits the composite sleeve 2 in which the outer layer 3 of the cemented carbide and the inner layer 4 of the steel material are metallically joined to the outer periphery of the shaft 1, Construct the trunk. An inner hole 5 coaxial with the rotating shaft is provided at an approximate position inside the shaft portion 1 corresponding to the width R of the rolling portion in the direction of the rotating shaft of the body, and the inner hole 5 is coaxial with the rotating shaft from the end face of the shaft neck 1b. The coolant is supplied to and discharged from the internal hole 5 through the through hole 6 communicating therewith.

In order to suppress a rise in the temperature of the portion of width R of the rolled portion that comes into contact with the rolled material, in the first invention, the inner hole 5
And is cooled from the inner surface by a refrigerant. In order to enhance the cooling efficiency, according to the second invention, a concave portion 7 is provided on the inner surface 10 of the inner hole 5 along the circumferential direction. Further, according to the third aspect of the present invention, an approximate portion corresponding to the width R of the rolled portion on the fitting surface 8 is brought into metal contact to improve the heat transfer to the inside and cool from the inside, and the body end E which originally has a small temperature rise. The temperature distribution in the direction of the rotation axis is made uniform by making the approximate portions corresponding to the above adiabatic contact.

The cooling from the inside of the roll of the present invention is performed by supplying the refrigerant from the direction of arrow A by the supply pipe 9 inserted into the internal hole 5 through the through hole 6 and the arrow B from the gap between the through hole 6 and the supply pipe 9. Discharge as follows. It is preferable that the supply pipe 9 is inserted coaxially with the roll rotation axis, and is freely supported by the support member 11 disposed inside the cylindrical member 1c against the roll rotation. In this case, the support member 11 is provided with a passage for the refrigerant to be discharged. The refrigerant is injected from the end of the supply pipe 9 in the direction of the rotation axis, and according to the fourth invention,
It is preferable that the fuel is injected toward the inner surface 10 of the inner hole 5 by the injection port 9b directed to the side of the tip 9a. A strong flow occurs in the layer of the refrigerant attached to the inner surface 10 due to the centrifugal force,
Cooling efficiency increases. In FIG. 1, the portion of the supply pipe 9 on the side connected to the refrigerant supply device is omitted. Although the supply pipe 9 is omitted in FIG. 2, it is preferable to arrange the supply pipe 9 in the same manner as in FIG.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The shaft portion 1 of the roll of the present invention is made of a steel material having a composition such as carbon tool steel or alloy tool steel manufactured by forging or casting, for example, as shown in FIG. 1 or FIG. I do. First, an inner surface hole is formed in the shaft portion 1 in which the drive-side DS shaft neck portion 1a, the body portion, and the operation-side WS shaft neck portion 1b are integrated. Next, a cylindrical member 1c having a hollow hole serving as a through hole 6 is fitted and fixed by interference fitting from the operation-side WS shaft neck portion 1b to the body portion to complete the internal hole 5. The reason why the inside from the trunk to the drive-side DS shaft neck 1a is hollow is to make the heat capacity equal to the operation side WS as much as possible.

The composite sleeve 2 is made of a WC-based material containing 50 to 90% by weight of WC on the outer periphery of a hollow cylindrical inner layer 4 material such as carbon steel, carbon tool steel, or alloy tool steel manufactured by forging, casting, rolling, or the like. The outer layer 3 of a cemented carbide is formed by HIP processing. The shaft portion 1 and the composite sleeve 2 are fitted and fixed by an interference fit or the like to form an assembling rolling roll using the cemented carbide of the present invention.

Although the fitting surface 8 is a metal contact, an approximate position corresponding to the width R of the rolled portion is a metal contact and an approximate position corresponding to the barrel end E is adiabatic as in the third invention. It may be contact. Means for making adiabatic contact is to make the fitting surface roughness rough or to cover with a heat insulating material and fit. For cooling the inside of the roll of the present invention, the refrigerant may be sent to the internal hole 5 using a simple straight pipe as the supply pipe 9, but it is preferable to inject the refrigerant toward the inner surface 10 as in the fourth invention. . Water or water containing rolling oil is used as the refrigerant.

[0019]

【Example】Example 1  1. An assembling type rolling row for a rolling mill before finishing a steel strip in the mode shown in FIG.
Prototype. The dimensions of the torso are 310mm in outer diameter and 500m in length
m, dimensions of operation side WS shaft neck 1b are outer diameter 170mm, length
 668 mm, the dimensions of the drive side DS shaft neck 1a are the same as the operation side WS.
It is almost the same. Body 310 mm outside diameter, 250 mm inside diameter, long
500 mm composite sleeve 2 with shaft part 1 outer diameter 250 mm,
0.8 / 1000 shrink fit to 500mm length corresponding to body
And fitted and fixed.

The composite sleeve 2 has a WC of 82% by weight,
Co 8%, Ni 8%, Cr 2% outer layer 3 and JIS SCM 440
And an inner layer 4 of a forged steel material. The outer layer 3 is formed on the outer periphery of the inner layer 4 by diffusion bonding at the same time as sintering by HIP processing. The position of the junction boundary between the outer layer 3 and the inner layer 4 is 275 m in diameter.
m position. The shaft portion 1 was machined from JIS SCM 440 forged steel to form a drive-side DS shaft neck portion 1a, a body portion, and an operation-side WS shaft neck portion 1b. The drive side D from the trunk in the shaft 1
A hollow hole having an inner diameter of 90 mm is formed on the S-axis neck portion 1a, and a cylindrical member 1c having a hollow hole with an inner diameter of 90mm is formed in the body portion and the operating side WS shaft neck portion 1b by forming an inner hole having an inner diameter of 130mm. It was fitted and fixed. Thus, the inner diameter is 90 m from the inner hole 5 to the drive-side DS shaft neck 1a.
m hollow hole, body diameter 130 mm, length in the rotation axis direction
A through hole 6 having an inner diameter of 90 mm was formed in the 300 mm internal hole 5 from the internal hole 5 to the operation side WS shaft neck 1b.

[0021]Example 2  The roll of the present invention prototyped in Example 1 was used for a steel band finishing stand.
Was used as a lower roll. Cold from the surface
In addition to cooling, it is cooled to a supply pipe 9 made of SGP steel pipe with a diameter of 38.1 mm.
Water was supplied to cool from the inside. Product width 250mm belt
I tried rolling 110 tons of steel,
No crack formation was observed. And the ma
There is almost no wear, and the rolling surface is beautiful,
It turns out that there is no problem and there is no problem with continued use
did.

[0022]

The assembly type rolling roll using the cemented carbide of the present invention has a problem in that the effect of tensile stress on the outer layer of the cemented carbide is small because the temperature rise of the shaft and the inner layer is small. There is no risk of breakage due to crack generation, and it can be used safely. In addition, the temperature distribution in the roll rotation axis direction tends to be equalized, and the thermal crown in the portion corresponding to the rolled material sheet width is small, so there is no disturbance of threading due to the progress of rolling, suitable for use in rolling of sheet material. It is. As a result, the excellent wear resistance and rough surface resistance of the cemented carbide can be sufficiently exerted, and the labor for changing the rolls and modifying the rolls can be omitted, thereby contributing to a reduction in man-hours and costs in the rolling process.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a first embodiment, a third embodiment, and a fourth embodiment of the present invention in a rotation axis direction.

FIG. 2 is a sectional view of a first embodiment, a second embodiment, and a third embodiment of the present invention in a rotation axis direction.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1; Shaft part 1a; Drive side shaft neck part 1b; Operation side shaft neck part 1c; Cylindrical member 2; Composite sleeve 3; Outer layer of cemented carbide 4; Inner layer of steel material 5; Internal hole 6; Through hole 7; Surface 9; Supply pipe 9a: Tip 9b; Injection port 10; Inner surface of internal hole 11; Support member Arrow A; Refrigerant supply direction Arrow B; Refrigerant discharge direction DS; Drive side WS; Operation side R; Rolling Part width E; trunk end

Claims (4)

[Claims] 1. A body made of a composite sleeve in which an outer layer of a cemented carbide and an inner layer of a steel material are metallically joined to the outer periphery of a shaft, and the width of a rolled portion in the rotation axis direction of the body is fitted. An internal hole coaxial with the rotating shaft is provided at a position inside the corresponding shaft portion, and a coolant is supplied to the internal hole and discharged through a through hole coaxial with the rotating shaft and leading from the end face of the shaft portion to the internal hole. An assembling type roll using a hard metal that is a feature. 2. A concave portion is provided along the circumferential direction on the inner periphery of the internal hole of the shaft portion at a position corresponding to the center portion of the body portion in the rotation axis direction. Assembling type roll using cemented carbide. 3. The fitting between the outer peripheral surface of the shaft portion and the inner peripheral surface of the composite sleeve and the portion corresponding to the width of the rolled portion are brought into metal contact with each other when fitting the composite sleeve to the outer periphery of the shaft portion. 3. The assembly type rolling roll using a cemented carbide according to claim 1, wherein a portion corresponding to the body end portion is adiabatically contacted. 4. A supply pipe for supplying the refrigerant to the internal hole, wherein the supply pipe is configured to inject the refrigerant from the side surface of the supply pipe inserted into the internal hole through the through hole toward the inner surface of the internal hole. An assembling type roll using the cemented carbide according to any one of claims 1 to 3.