JPH04274808A - Grinding device and method for circular member, columnar or cylindrical member and material to be rolled - Google Patents

Abstract

PURPOSE:To maintain specified cutting quality as grinding is executed by a slurry 4 contg. an abrasive and consequently to prevent working flaws, such as feed marks and to greatly enhance roundness. CONSTITUTION:This device has a driving device for rotating a cylindrical material 1 to be ground, a pad 3 to be pressed to this material to be ground, a pressing means for pressing this pad to the material to be ground, and a slurry supplying means 11 for supplying the slurry 4 contg. the abrasive between the material to be ground and the pad.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for polishing circular members such as rolling rolls, and also to circular members and rolled materials.

0002

2. Description of the Related Art Conventional polishing devices for circular members can be roughly divided into the following three types. One is lathe processing using a cutting tool whose main purpose is grinding. The second method is cylindrical grinding and cylindrical polishing using a rotating grindstone (Japanese Patent Application Laid-Open No. 61-7
1953, JP-A-1-199705). 3
The pawl is a centerless process that provides excellent roundness, especially for small items.

0003

[Problems to be Solved by the Invention] In all of the above-mentioned conventional techniques, backlash and vibration of the polishing device reduce machining accuracy.
In particular, it caused a decrease in roundness and machining scratches such as feed marks. Here, roundness refers to the difference between the outermost diameter and the minimum diameter of the circular outer surface of a circular member, and the smaller the difference, the better the roundness. That is, when the roundness is excellent, the circumferential waviness of the outer surface is small. When polishing a circular member using a rotary whetstone, which is the most commonly used method, both the workpiece to be polished and the shaft of the rotary whetstone are fixed. The play in the shaft bearing and the slide table reduce roundness and cause machining scratches such as feed marks.

[0004] Particularly when the object to be polished becomes hard, the polishing surface pressure increases, and the above-mentioned defective phenomena tend to increase. In addition, when polishing circular parts with a rotating whetstone,
As the polishing time becomes longer, the grindstone becomes harder to sharpen and wears unevenly, resulting in scratches caused by galling. Therefore, the grindstone has to be sharpened at predetermined intervals, and only skilled workers are required to process the grindstone, resulting in a decrease in work efficiency. For example, in conventional polishing using a rotating grindstone, the roundness is about 1 to 2 μm, and it is difficult to completely remove the feed marks.

[0005] The purpose of the present invention is to reduce backlash and vibration of polishing equipment,
In addition, it essentially improves the reduction in processing accuracy due to reductions in sharpness of the grindstone, etc., and has excellent roundness, i.e., small circumferential waviness on the outer surface of the circular member, and a polishing device for circular members with fewer processing scratches such as feed marks. The object of the present invention is to provide a method, a circular member, and a rolled material.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a drive device that rotates a cylindrical or cylindrical object to be polished in the circumferential direction, and a drive device that is pressed against the circumferential surface of the object to be polished. This is a polishing device for a circular member, comprising a pad, a pressing means for pressing the pad against the object to be polished, and a slurry supply means for supplying slurry containing an abrasive between the object to be polished and the pad. Here, the pad is preferably made of a material softer than the polished surface of the object to be polished.

The present invention also provides a drive device that rotates a columnar or cylindrical object to be polished in the circumferential direction and reciprocates it parallel to the axial direction, and A pad that contacts at least two places on the surface, a pressing means for pressing the corresponding object against the object to be polished, and a slurry supply means for supplying a slurry containing abrasive grains between the object to be polished and the pad. A polishing apparatus for a circular member is characterized in that it is equipped with the following features.

[0008] In the above-mentioned polishing apparatus, it is preferable that the pad is swingable to follow the radial movement of the object to be polished and is in contact with the object in a non-rotating manner. Further, it is preferable that the pad has a concave curved surface in contact with the object to be polished. Further, it is preferable that the pad has a structure in which it contacts at least two places on the same circumferential surface of the object to be polished.

In the polishing device, the pressing means includes a holding part that holds the pad, a support rod that rotatably supports the holding part at one end, and a load receiving part provided at the other end of the support rod. , and a fulcrum that supports the support rod in the middle. Further, the pressing means preferably includes a holding part that holds the pad, and an urging means that urges the holding part by a spring force or magnetic force.

[0010] In the polishing apparatus, it is preferable that the slurry supply means continuously passes the slurry between the object to be polished and the pad.

[0011] Further, in the present invention, while pressing a non-rotating pad against the circumferential surface of a cylinder or cylindrical object rotating in the circumferential direction, a slurry containing abrasive grains is applied between the object to be polished and the pad. This is a method of polishing a circular member by supplying and polishing it.

[0012] Further, the present invention provides a method of bringing a pad into contact with and pressing at least two places on the circumferential surface of a columnar or cylindrical object to be polished that reciprocates in parallel with the axial direction while rotating.
The polishing is performed by making the pad freely movable in the pressing direction according to the movement of the object to be polished in the radial direction, and supplying slurry containing abrasive grains between the object to be polished and the pad. This is a method of polishing a circular member. Here, it is preferable to use coarse abrasive grains at the initial stage of polishing, and then use finer abrasive grains in sequence. Further, it is preferable to continuously pass a slurry containing an abrasive between the object to be polished and the pad. Further, it is preferable to shave the surface of the object to be polished by 1 to 5 μm.

The present invention also provides a cylindrical or cylindrical member made of a ceramic sintered body, characterized in that the outer surface has a circumferential waviness of 0.3 μm or less. The present invention also provides a cylindrical or cylindrical member made of a metal member, characterized in that the outer surface has a circumferential waviness of 1 μm or less. Here, it is preferable that the polishing surface be approximately the same over the entire length. Further, the ceramic or metal member is preferably a rolling roll. Further, it is preferable that the grinding marks on the roll surface be random and have no directionality.

The present invention also provides a composite roll for metal rolling in which the outer periphery of a core material is covered with an outer layer material, wherein the core material is made of low alloy steel having a shore hardness of 35 or more and lower hardness than the outer layer material. , the outer layer material has a martensitic structure with a Shore hardness of 80 or more and a residual austenite content of 15% by volume or less, has an outer surface circumferential waviness of 1 μm or less, has compressive residual stress on the outermost surface, and has a compressive residual stress in the roll axis direction. This is a composite roll for metal rolling, characterized by being made of solidified high-alloy steel.

The present invention also provides a composite roll for metal rolling in which the outer periphery of a core material is covered with an outer layer material, wherein the core material has a weight of C.
0.5-1.0%, Si 1% or less, Mn 1% or less, Cr
1 to 5%, and less than 0.5% of Mo, and has a lower hardness than the outer layer material, and the outer layer material has a C content of 0.5% or less by weight.
0.5-1.5%, Si0.5-3.0%, Mn1.5
% or less, Cr2~10%, Mo1~12%, V0.5~
A composite roll for metal rolling, characterized by a weld layer solidified in the axial direction of the re-roll made of high alloy steel containing 2.0% and W0.1 to 20% or less, and an outer surface circumferential waviness of 1 μm or less. be.

The present invention also provides a rolled metal material, characterized in that the surface of the rolled metal material has waviness of 0.3 μm or less.

[0017] The present invention also provides a rolling mill in which a work roll is rotated sub-rotated by the rotational drive of an intermediate roll or a reinforcing roll, wherein the work roll is a ceramic roll in the shape of a long round bar, and the outer surface of the roll is The circumferential waviness of the work roll is 0.3 μm or less, bearings are disposed in contact with each end surface of the work roll to restrain the axial movement of the work roll, and the work roll has a circumferential waviness of 0.3 μm or less, The rolling mill is characterized in that a support roll is disposed in contact with the work roll to restrain movement of the work roll in the rolling direction. Here, it is preferable that at least one of the intermediate roll, reinforcing roll, work roll, and support roll is provided with a crown.

The present invention also provides a molten metal plating apparatus equipped with a roll that rotates in molten metal while being supported by a bearing, wherein the shaft sliding part of the roll and the sliding part of the bearing are made of a ceramic sintered body, Continuous molten metal plating characterized in that the roll is made of metal, a cylindrical ceramic sintered body is fitted on the outer circumference of the shaft, and the outer surface waviness of the sintered body is 0.3 μm or less. It is a device.

The present invention also provides a molten metal plating apparatus equipped with a sink roll and a support roll that rotate while being supported by bearings in the molten metal, wherein at least one of the sink roll and the support roll is made of metal; A continuous hot-dip metal plating apparatus, characterized in that a cylindrical ceramic sintered body containing a solid lubricant is fitted on the outer periphery of the shaft, and the outer surface waviness of the sintered body is 0.3 μm or less. be.

[0020]

[Operation] Polishing is performed by passing a slurry containing an abrasive between the rotating workpiece and the abutment, that is, the abrasive is in a fluid state and is not fixed, so the abrasive is spread in multiple directions. It can move with a degree of freedom, and grinding marks are less likely to occur. Therefore, it is possible to prevent the occurrence of polishing scratches in the circumferential direction as seen with conventional rotary grindstones. In addition, the sharpness does not deteriorate with the passage of polishing time, and a constant sharpness can be maintained at all times, and the occurrence of uneven polishing and scratches depending on the location can be prevented. Examples of the abrasive material contained in the slurry include ceramic powders such as SiC, Al2O3, and silicon carbide, and diamond, but any material having a hardness that can polish the object to be polished may be used. Particle size is 100
The thickness is preferably 20 μm or less, preferably 20 μm or less. Water is a good solvent for making a slurry. A rust preventive dispersant may be added.

Furthermore, by changing the particle size and hardness of the abrasive used, the surface roughness of the polished surface can be changed as appropriate. Further, since the pad is made of a softer material than the object to be polished, a concave portion is naturally formed in the initial stage of polishing, and it is evenly pressed against the object to be polished, thereby preventing polishing scratches due to uneven contact or the like.

Furthermore, the pad has a structure that allows it to follow the axial displacement due to vibrations generated during rotation and axial traverse of the polished object with a constant pressing pressure, so that the roundness is improved. It is possible to prevent the occurrence of polishing scratches such as feed marks.

Furthermore, when the circular member according to the present invention is used as a rolling roll, since the circumferential waviness of the outer surface is small, the waviness is hardly transferred to the surface of the material to be rolled, resulting in so-called chatter marks. It is possible to finish the rolled material without any cracks.

[0024] As rolling rolls, sialon, zirconia, silicon carbide (SiC) and silicon nitride (Si3N4) are used.
There are ceramic rolls made of such materials, and metal rolls made of hard-to-grind metals such as carbide rolls and high-speed steel rolls.

[0025] As a core material, C0.5 to 1.0%, Si≦
1%, Mn≦1%, Cr1-5%, Mo≦0.5%, and an outer layer material having the following components is formed by electroslag welding, centrifugal casting, thermal spraying, etc. C is necessary for forming carbides to improve wear resistance and ensuring base hardness. When the amount is less than 0.5%, the amount of carbide is small and the wear resistance is not sufficient. On the other hand, if C exceeds 1.5%, network carbides precipitate at grain boundaries increase, resulting in poor roughness resistance and toughness. In particular, 0.8 to 1.2
% is preferred. Si is an element necessary as a deoxidizing agent,
It has 0.5% or more and also improves tempering resistance. However, if the amount exceeds 3.0%, embrittlement tends to occur. In particular, 1 to 3% is preferable, and 1.5 to 2.5% is more preferable. Mn has a deoxidizing effect and also removes S which is an impurity.
S has a fixing effect, but if its amount exceeds 1.5%, retained austenite increases, making it impossible to maintain stable and sufficient hardness, and reducing toughness. In particular, 0.2
-1.0% is preferable, and 0.2-0.5% is more preferable. If Cr is less than 2%, the hardenability is poor, and if it exceeds 10%, there will be too much Cr-based carbide, which is disadvantageous. In particular, 3 to 7% is preferable, and 3.5 to 5% is more preferable. Mo and W combine with C to form M2C or M5C carbides, and also form a solid solution in the matrix to strengthen the matrix and improve wear resistance and tempering resistance. However, when it is excessive, M6C carbides increase and toughness and roughness resistance decrease. The upper limits of Mo and W should be 12% and 20%, respectively, and the lower limits of W and Mo should be 1% or more. Mo is preferably 1.5 to 4.5% in semi-high speed steel or 7 to 10% in high speed steel, and W is preferably 0.1 to 1% in semi-high speed steel or 0.5 to 5% in high speed steel. V forms MC-based carbides and contributes to improving wear resistance, but
If it is less than 0.5%, there is no sufficient effect, and if it exceeds 5%,
Significantly inhibits grindability. In particular, 0.7 to 2.0% is preferable. Co is an element for obtaining high hardness by solid solution in the matrix and high temperature tempering, but if it is less than 5%, its effect is insufficient. If it exceeds 15%, toughness decreases. Especially 6-10%
is preferred. In particular, as the outer layer, semi-high-speed steel has the above-mentioned C,
Contains Si, Mn and Cr, W0.1-1%, V0.5
~2.0% and Mo1~5% or high speed steel W0.5~3
%, 5-11% or 12-20%, Mo4-12%, V
Co: 0.5 to 1.5% or 1.5 to 5%, or a combination thereof may contain Co: 4 to 20%. In a composition based on Hot, the amount of carbide is considered to be important for wear resistance and seizure resistance, so the amount of carbide is large. The larger the amount of carbide, the more difficult it is to finish by grinding, the lower the toughness, and the less able it is to withstand high local pressures like cold work rolls. Therefore, the alloy composition of cold work rolls is designed to reduce the amount of carbide (carbon content) to an extent that does not impair wear resistance, and strengthens the matrix (martensite, especially tempered martensite) to withstand local pressure (rolling pressure). That's what I do. Co is effective for reinforcing this matrix, and high hardness can be obtained. Note that the high alloy steel used for the outer layer of the present invention can contain 5% or less of Ni.

[0026]

EXAMPLES Example 1 Examples of the present invention will be described below with reference to the drawings. Figure 1
2 shows a schematic side view of the polishing device, and FIG. 3 shows a plan view thereof. A circular object 1 to be polished is held by a drive device (not shown) so that it can rotate and move back and forth in the axial direction. The drive device is configured so that the polishing time is approximately constant over the entire length of the object 1 by repeating the reciprocating movement. The circumferential speed during rotation is about 1 to 10 m/min. This object to be polished 1 is processed into a rolling roll or the like. This embodiment is a ceramic roll, and metal shafts 2 are fitted at both ends.

Two surfaces of the V-shaped pad 3 are in contact with the lower surface of the object 1 to be polished. This V-shaped pad 3 is made of a material softer than the object 1 to be polished. As a result, a concave portion 5 having a concave curved surface shape is naturally formed, and it is evenly pressed against the object to be polished 1, thereby preventing polishing scratches due to uneven contact or the like. Note that the recess may be formed in advance. The pad 3 is held in a holding part or support block 6 of the pressing means.

The pressing means includes a holding portion, that is, a support block 6 that holds the pad 3, a support rod 8 that rotatably supports the support block 6 at one end, and a support rod 8 provided at the other end of the support rod 8. It consists of a receiving part for the load 10 and a fulcrum 9 that supports the support rod 8 in the middle. Therefore, since the support rod 8 can swing around the fulcrum 9, the contact pressure between the pad 3 and the workpiece 1 remains almost constant even if the workpiece 1 vibrates minutely during polishing. In addition, as a means for making this contact pressure constant, the support block 6 may be directly biased by a spring force or magnetic force instead of the load 10, the support rod 8, etc. The support block 6 is connected to a support rod 8 by a rotating shaft 7, so that the support 3
is adapted to swing to follow the movement of the object 1 to be polished during polishing. Therefore, the pad 3 freely moves in the pressing direction according to the unevenness of the object 1 to be polished, and comes into contact with the object 1 without rotation.

A slurry supply means 11 for supplying a slurry 4 containing an abrasive is provided between the object to be polished 1 and the pad 3. In this embodiment, the slurry 4 can be dripped from a tank and continuously supplied. Since the conventional device can also finish the roundness to about 3 μm, the device according to the present invention preferably cuts the roundness by about 1 to 5 μm. By grinding to this extent, it is possible to manufacture a ceramic roll whose outer surface has an average circumferential waviness of 0.3 μm or less. If this circumferential waviness is 0.3 μm or less,
Since only grinding scratches of 0.3 μm or less are transferred to the surface of the rolled material rolled by the rolls, so-called chatter marks are not generated. Preferably, the waviness is 0.1 μm or less. A rolled material with surface waviness of 0.3 μm or less has excellent surface properties because it has almost no grinding marks.

A method of cylindrical polishing of a sialon ceramic roll (hereinafter referred to as sialon roll) will be explained based on FIG. 3. This roll was manufactured by the following method. The starting material was 85wt% Si3N4,
7wt% Y2O3, 5wt% Al2O3 and 3wt
% AlN. Add to this 1.4wt% based on the raw material powder.
PVB (polyvinyl butyral) and 40 wt % of industrial methanol were added, wet mixed for 4 hours in a pot mill, and then a granulated powder with an average particle size of 65 μm was obtained using a centrifugal spray dryer. The molding was performed using a cold isostatic press at a pressure of 100 MPa. Then 500℃
After removing the resin in the molded body using a degreasing furnace and pre-firing,
Primary cutting is performed to obtain a surface roughness of approximately 3 μm, and then suspended in the axial direction in a graphite induction heating type firing furnace.
．． Firing was performed at 1750° C. in pressurized nitrogen gas of 9 MPa. Sialon after firing is Si5.5Al0.5O0.5
It has a composition shown by the chemical formula N7.5. Finally, the sintered body was ground and polished to the desired roll dimensions. A sialon roll 1 having an outer diameter of 40 mm and a length of 500 mm, which has been ground and polished to a roundness of approximately 3 μm, is set in an ordinary cylindrical polishing device with both centers fixed. Next, a width 5 that is softer than this roll
Two aluminum nitride pads 3 having a diameter of 0 mm, a length of 40 mm, and a thickness of 10 mm are fixed to a metal support block 6 at an angle of 90°. The support block 6 includes a support rod 8 and a rotating shaft 7.
are connected by. Further, the support rod 8 is fixed at a fulcrum 9. The hardness of the sialon roll is 16 GPa, the hardness of the pad is 13 to 14 GPa, and the hardness of the abrasive silicon carbide powder is 24 GPa. For polishing, first use the Sialon roller.
After rotating the wheel 1 at a circumferential speed of 2 m/min, the weight 10
, and press the pad 3 against the Sialon roll 1. Further, a slurry 4 of silicon carbide powder having a particle size of 15 to 20 μm and water is continuously dripped into the contact area between the sialon roll 1 and the pad 3. Furthermore, the sialon roll is traversed left and right. Traverse speed is 10
Approximately 0 mm/min is preferable. Silicon carbide slurry used
are made finer in order according to the desired surface roughness. In this example, the particle size of silicon carbide powder was 15 to 20 μm.
, 10 to 15 μm, 5 to 8 μm, and 1 to 2 μm, and polishing was performed for about 10 minutes each. Further, the peripheral speed was increased as the particle size became finer, and for example, in the case of a particle size of 1 to 2 μm, the peripheral speed was set to 7 m/min. As a result, it was possible to obtain a sialon roll with a circularity of 0.1 μm or less and no processing flaws such as feed marks. In the above description, the outer surface of the circular member is polished, but the inner surface of the cylindrical member can also be polished in the same manner by pressing a pad against the inner surface.

FIG. 4 shows the measurement results of the waviness of the ceramic roll surface 12 manufactured by the polishing apparatus according to the present invention. FIG. 5 shows the waviness of the surface 12 of the conventional example. It can be seen that the roll surface according to the present invention has extremely small waviness,
It was the same polished surface throughout its entire length. Furthermore, even if there were grinding marks, they were random and had no directionality.

Next, a rolling mill equipped with rolling rolls according to the present invention will be explained based on FIGS. 8 and 9. In the figure,
Reference numeral 13 denotes a work roll made of high-strength sialon with a bending strength of 80 kgf/mm2, and is in the shape of a round bar with a diameter of 20 mm and a length of 100 mm. The work roll 13 is a round bar shape with metal caps fitted at both ends (bonded with adhesive) and manufactured by the method described above. The dimensional accuracy and surface accuracy of the work roll 13 are equivalent to those of a metal roll. A reinforcing roll 14 consisting of a shaft portion and a body portion is pressed against the work roll 13, and the work roll 13 is rotated by rotation of the reinforcing roll 14. The shaft portion of the reinforcing roll 14 is rotationally driven by an electric motor (not shown) via a universal joint (not shown) and a reduction gear (not shown). Further, the shaft portion of the reinforcing roll 14 transmits rolling reaction force to a bearing (not shown) provided on the shaft portion. Work roll 13
A steel ball 18 is arranged on each end face of the steel ball 18 so as to be in contact with the center of the end face, and the steel ball 18 is rotatably supported by a steel ball support 19. Therefore, the movement of the work roll 13 in the axial direction is restricted. Also, work roll 13 and steel ball 1
The sliding speed with respect to No. 8 is low, so that burning etc. does not occur. A support roll 15a is disposed in contact with the work roll 13 before and after the work roll 13 in the rolling direction, and another support roll 15b is further disposed in contact with the support roll 15a. Another support roll 15b serves to reinforce support roll 15a. Support roll 15a and another support roll 15b are supported by bearings 17. The bearing 17 is housed in a bearing box 16. Since support rolls 15a are disposed in contact with the work roll 13 before and after the work roll 13 in the rolling direction, movement of the work roll 13 in the rolling direction is restrained. 20 is a rolled material rolled by the work rolls 13, which is a stainless steel plate (SUS3) with a width of 50 mm and a thickness of 0.2 mm.
04) is used.

[0033] As a result of conducting a rolling experiment with the reinforcing roll 14 rotated at a speed of 30 revolutions per minute, the rolled material 20 was sufficiently rolled. FIG. 6 shows the surface of a rolled material of SUS304 with a thickness of 0.2 mm, which was rolled by a rolling mill shown in FIGS. 8 and 9 described later and equipped with a rolling roll according to the present invention shown in FIG.
This is a 0x enlarged view, and FIG. 7 is a 50x enlarged view of the surface of a rolled material rolled by the conventional rolling roll of FIG. In the case of the conventional example, grinding marks are transferred, but in the case of the present invention, there are almost no such marks. In this case, a rolled material with good gloss could be obtained without damaging the ceramic work roll 13.

Example 2 In the case of a metal roll, the circumferential waviness may be 1 μm or less. In the case of a metal roll, the waviness is reduced and transferred to the surface of the material to be rolled, so this level is sufficient. The thickness is preferably 0.5 μm or less. An example of the structure and manufacturing method of the metal roll will be specifically shown below. Body diameter 750mm
An ingot for a composite roll having an outer diameter of 850 mm was manufactured by electro-remelting a roll having a body length of 1480 mm and a shaft member having a diameter of 665 mm as follows.

The apparatus for manufacturing a composite roll by the electroslag overlay method includes a welding machine, an amplifier, current supply wiring, a carbon brush, a thermocouple for temperature measurement, a DC motor, and a manipulator. The manipulator is moved by a DC motor such that a tubular consumable electrode, a consumable electrode made of high speed tool steel, supported by the arm of the manipulator is moved upwardly. A core shaft made of low-alloy steel is installed on a rotating surface plate. A water-cooled mold is installed concentrically with this core shaft, and an annular ignition plate (i.e., mold bottom) is installed close to the lower end of the core shaft in the space between the two. The core shaft and water-cooled mold were rotated at 5 rpm in the circumferential direction. A tubular electrode supported by a manipulator is inserted into the space defined by the core shaft and the water-cooled mold, that is, the melting chamber, and an alternating current is supplied between the core shaft and the tubular electrode via wiring. As a result, the tubular electrode is melted and consumed. Five carbon brushes are placed evenly around the surface plate, and multiple wires are placed on the tubular electrode so that the current flows evenly through each part.When an arc is generated due to energization, the slag is heated by the resistance. As it melts, molten metal is formed, which is cooled and solidified by contact with the water-cooled mold, and a uniform build-up layer is formed on the surface of the core shaft. During this time, the water-cooled mold is moved upward coaxially with respect to the core axis. The slag is always adjusted to a thickness of 50 to 60 mm. Furthermore, the annular bottom plate prevents the molten metal from dripping downward. The current and voltage are controlled to be kept constant during melting, and the thickness of the overlay layer and the depth of penetration into the core material are controlled to be constant.

[0036] The overlay layer of the thus obtained composite roll was forged at 1100°C to have an outer diameter of 780 mm and an outer layer thickness of 42.5 mm. Furthermore, the built-up layer is subjected to quenching and tempering heat treatment, thereby making it possible to obtain a surface hardness of Hs90 or more of the built-up layer. After heat treatment, it is finished by cutting and polishing to have an outer diameter of 750mm.
It was cut to 3 mm and then similarly polished using the equipment described above. It was polished to an average surface roughness of about 0.5 μm.

[0037] The chemical composition of the outer layer material is shown in Table 1 below (wt%).
Shown below. This roll was further heat treated by quenching at 1000-1200°C and tempering at 120-520°C for 10-20 hours. Heat treatment was carried out in a manner appropriate for this material. The shaft material of the roll of the present invention contains 0.9% and 3% C.
Cr forged steel was used, and its hardness was HS40.

[0038]

[Table 1]

Example 3 In a continuous hot-dip plating apparatus, a steel strip, which is a material to be plated, is wound around a payoff reel, and a leveler,
After passing through a shear and a welder, it passes through an electrolytic cleaning tank, a scraper, and a rinsing tank before entering an annealing furnace, where it is annealed and then plated in a hot-dip plating tank. The dip-plated strip travels directly upwards at high speed, passes through a surface conditioning device, bridle roll device, skin pass mill, tension leveler, chemical conversion treatment device, etc., and then passes through a looper and is wound onto a tension reel. The tension applied to the strip is controlled by a roll device and tension bridle.

The magnitude of this tension is determined by the strip 21
It is provided immediately after passing through the wiping nozzle 27, and is controlled to be constant based on the magnitude of the amplitude measured by a vibration detector. Tension bridles are provided at each processing stage. FIG. 10 shows an enlarged view of the plating apparatus. The strip 21 fed through the snout 31 is deflected in the plating bath 30 by a sink roll device 24, and the movement of the strip is stabilized by a support roll device 25. The strip 21 is run at a high speed of 50 to 100 m/min. Furthermore, the strip drawn out from the plating bath 26 is passed through wiping nozzles 27 provided on both sides of the strip.
Gas is sprayed at a higher velocity, and the plating thickness is adjusted by adjusting the gas pressure and spray angle. Rolls and roll bearing shells 29 of support roll apparatus 25 and sink roll apparatus 24 used in hot dip metal plating baths
is lubricated by molten metal, so the roll bearing shell 2
9 has a sliding bearing structure. In Fig. 10, it is observed that the wear of the roll bearing progresses in the direction indicated by the arrow, that is, in the vector direction of the force generated when the strip 21 is bent by the sink roll device 24. I found out by doing this.

FIG. 11 shows a sectional view of a sink roll according to the present invention. 4 attached to the roll shaft 33
As the divided ceramics 32, Sialon ceramics were selected which exhibited excellent corrosion resistance against molten metal and had high strength and high hardness characteristics. The chemical formula of Sialon ceramics is expressed by the following formula.

[0042]

[Chemical formula 1]

[0043] Here, z can be any value between 0 and 4.2, and this is called β-sialon. In this example, SiAlON powder having a composition of Z=0.5 was used, and after adding a small amount of binder, it was wet mixed in methanol and granulated by a spray drying method. Next, using a cooling isostatic press method, the outer diameter was 210 mm, the inner diameter was 145 mm,
Four cylindrical molded bodies each having a length of 50 mm were molded. The firing temperature was 1750°C, and the firing was performed in a nitrogen atmosphere in the same manner as described above. Furthermore, the sintered body was finished to an outer diameter of 150 mm and an inner diameter of 1.
The length was 18 mm and the length was 40 mm. Note that the surface roughness of the outer diameter sliding surface was Rmax 0.8 μm. This material was polished in the same manner as described above by fitting a metal rod inside.

The roll shaft 33 is made of relatively corrosion-resistant stainless steel AISI316, and has an outer diameter of 111mm.
15mm finished. The buffer material 34 is tempered,
A copper plate having a yield point of about 5 kgf/mm2 was used, the plate thickness was 3.2 mm, and slits 40 and protrusions 41 were formed as shown in the plan view. Furthermore, the copper buffer plate 34 is attached to a roll shaft 33 corresponding to each cylindrical ceramic as shown in FIG.
wrapped around. Next, a cylindrical sialon sintered body is inserted into the roll shaft, and as shown in FIG. 11, the ceramics 2 is pressed in the axial direction with a force of about 600 kgf using a holding plate 35, a cap 36, an Inconel spring 37, and a bolt screw 38. By fixing the ceramics 32 and the roll shaft 33
This prevents molten Zn from entering between the two.

By the way, sialon ceramics, copper,
The coefficient of thermal expansion of each stainless steel roll shaft is 3.2×
10￣6/℃, 13×10￣6/℃, 18×10￣6/
11 is immersed in molten Zn with a molten metal temperature of 450°C, the inner diameter of the sialon ceramic 32 is 118.17 mm, the outer diameter of the stainless steel roll shaft 33 is 112.05 mm, and the gap is 3. .0
It will be 6mm. On the other hand, since the intermediate material 34 made of a copper buffer plate is 3.22 mm, the difference with the gap is 0.16 mm.
This is the plastic deformation allowance. Since the amount of plastic deformation is approximately 5%, slits or the like corresponding to at least 5% of the volume were provided. As a result, at the operating temperature, the buffer material 34 was plastically deformed, and the roll shaft 33 and the ceramics 32 came into close contact with each other, and no cracking of the ceramics 32 occurred due to the fitting. This seems to be because there is a space in the gap where the cushioning material 34 can be deformed even at the operating temperature. If the buffer plate 34 between the cylindrical ceramic 32 and the roll shaft 33 is made of copper, it is likely to get wet with Zn, and if Zn enters the gap and fills the space, there is a risk that the ceramic 32 will crack. It is preferable to use a buffer material at the end to prevent Zn from entering. It is better to use stainless steel wire. SiC-C composite ceramics, which has excellent solid lubricity and corrosion resistance against molten Zn, was attached to the inner peripheral surface of the stainless steel bearing.

[0046]

[Effects of the Invention] According to the present invention, since the polishing is performed using a slurry containing an abrasive, the sharpness can be kept constant, and processing scratches such as feed marks can be prevented, and the roundness can be greatly improved. Can be done. Furthermore, by changing the particle size of the abrasive, the surface roughness of the polished surface can be easily changed.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged side view of a polishing apparatus according to the present invention.

FIG. 2 is a schematic side view of the polishing apparatus.

FIG. 3 is a schematic plan view of the polishing apparatus.

FIG. 4 is a diagram showing measurement results of waviness on the surface of a roll manufactured by the polishing apparatus according to the present invention.

FIG. 5 is a diagram showing waviness on the roll surface of a conventional example.

FIG. 6 is a 50 times enlarged view of the surface of a rolled material rolled by the rolling roll according to the present invention.

FIG. 7 is a 50 times enlarged view of the surface of a rolled material rolled with a conventional rolling roll.

FIG. 8 is an explanatory diagram showing the arrangement of rolls of a rolling mill according to the present invention.

9 is a cross-sectional view taken along line AA in FIG. 8. FIG.

FIG. 10 is an enlarged sectional view of a continuous hot-dip plating apparatus.

FIG. 11 is a sectional view of a sink roll according to the present invention.

[Explanation of symbols]

1 Material to be polished 3 Guessing item 4 Slurry 5 Recess 6 Support block 7 Rotation axis 8 Support rod 9 Fulcrum 10 Weight 11 Tank 12 Surface

Claims (25)

[Claims] 1. A drive device that rotates a cylindrical or cylindrical object to be polished in the circumferential direction, a pad that is pressed against the circumferential surface of the object to be polished, and a press that presses the pad against the object to be polished. An apparatus for polishing a circular member, comprising: a means for polishing a circular member; and a slurry supply means for supplying a slurry containing an abrasive between the object to be polished and the pad. 2. The polishing apparatus according to claim 1, wherein the pad is made of a material softer than the polishing surface of the object to be polished. 3. A drive device that rotates a cylindrical or cylindrical object to be polished in the circumferential direction and reciprocates in parallel with the axial direction; It is equipped with a pad that contacts the object at a certain point, a pressing means for pressing the corresponding object against the object to be polished, and a slurry supply means for supplying a slurry containing abrasive grains between the object to be polished and the object. Features: Polishing device for circular parts. 4. A polishing apparatus for a circular member according to claim 1, wherein the pad is swingable to follow the radial movement of the object to be polished and is in non-rotating contact with the object. 5. The polishing device according to claim 1, wherein the pad is a circular member whose contact surface with the object to be polished is formed into a concave curved surface. 6. An apparatus for polishing a circular member according to claim 1, wherein the pad has a structure in which the pad contacts at least two places on the same circumferential surface of the object to be polished. 7. In any one of claims 1 to 6, the pressing means includes a holding part that holds the pad, a support rod that rotatably supports the holding part at one end, and a support rod that rotatably supports the holding part at one end. A polishing device for a circular member, comprising a load receiving portion and a fulcrum that supports the support rod in the middle. 8. In any one of claims 1 to 7, the pressing means is used for polishing a circular member comprising a holding part for holding the pad and a biasing means for urging the holding part by a spring force or magnetic force. Device. 9. The apparatus for polishing a circular member according to claim 1, wherein the slurry supply means continuously passes the slurry between the object to be polished and the pad. 10. A non-rotating pad is pressed against the circumferential surface of a cylinder or cylindrical object to be polished that rotates in the circumferential direction, and a slurry containing abrasive grains is supplied between the object to be polished and the pad. A method for polishing a circular member, the method comprising polishing. 11. A pad is brought into contact with and pressed at least two places on the circumferential surface of a columnar or cylindrical object to be polished, which reciprocates in parallel with the axial direction while rotating, and the pad is moved to a radius of the object to be polished. A method for polishing a circular member, characterized in that the slurry is movable in the pressing direction according to the movement in the direction and is polished by supplying a slurry containing abrasive grains between the object to be polished and the pad. 12. The method of polishing a circular member according to claim 10, wherein the abrasive grains are coarsely used in the initial stage of polishing, and the abrasive grains are sequentially finely polished. 13. The method of polishing a circular member according to claim 10, 11 or 12, wherein the surface of the object to be polished is shaved by 1 to 5 μm. 14. A cylindrical or cylindrical member made of a ceramic sintered body, characterized in that the outer surface has a circumferential waviness of 0.3 μm or less. 15. A cylindrical or cylindrical member made of a metal member, characterized in that the outer surface has a circumferential waviness of 1 μm or less. 16. A cylindrical or cylindrical member according to claim 14 or 15, having substantially the same polishing surface over its entire length. 17. The columnar or cylindrical member according to claim 14 or 15, wherein the ceramic or metal member is a rolling roll. 18. The cylindrical or cylindrical member according to claim 17, wherein the roll surface has grinding scratches that are random without directionality. 19. A composite roll for metal rolling in which the outer periphery of a core material is covered with an outer layer material, wherein the core material has a shore hardness of 35.
The outer layer material is made of a low alloy steel having a hardness lower than that of the outer layer material, and the outer layer material has a martensitic structure with a Shore hardness of 80 or more and a retained austenite amount of 15% by volume or less,
A composite roll for metal rolling, characterized in that the outer surface has circumferential waviness of 1 μm or less, has compressive residual stress on the outermost surface, and is made of high alloy steel solidified in the roll axis direction. 20. A composite roll for metal rolling in which the outer periphery of a core material is covered with an outer layer material, wherein the core material has a weight of C0.5 to
1.0%, Si 1% or less, Mn 1% or less, Cr 1-5%
, is made of low alloy steel that contains Mo0.5% or less and has lower hardness than the outer layer material, and the outer layer material has a C0.5 to C0.5% by weight.
1.5%, Si 0.5-3.0%, Mn 1.5% or less,
Cr2~10%, Mo1~12%, V0.5~2.0%
, a weld layer solidified in the axial direction of the re-roll made of high alloy steel containing W0.1~20% or less, and the outer surface circumferential waviness is 1μ
A composite roll for metal rolling, characterized in that the roll is less than m. 21. A rolled metal material, characterized in that the surface of the rolled metal material has waviness of 0.3 μm or less. 22. A rolling mill in which a work roll is rotated sub-rotated by the rotational drive of an intermediate roll or a reinforcing roll, and the work roll is a ceramic roll in the shape of a long round bar, and the outer surface of the roll is rotated in the circumferential direction. Swell is 0
．． 3 μm or less, bearings are disposed in contact with each end surface of the work roll to restrain the movement of the work roll in the axial direction, and support rolls are provided in contact with the work roll before and after the rolling direction of the work roll. A rolling mill characterized in that movement of the work rolls in the rolling direction is restrained by arranging the work rolls. 23. The intermediate roll according to claim 22,
A rolling mill characterized in that at least one of a reinforcing roll, a work roll, and a support roll is provided with a crown. 24. A molten metal plating apparatus comprising a roll that rotates while being supported by a bearing in molten metal, wherein the shaft sliding part of the roll and the sliding part of the bearing are made of a ceramic sintered body, and the roll is 1. A continuous hot-dip metal plating device made of metal, having a cylindrical ceramic sintered body fitted to the outer periphery of its shaft, and having an outer surface waviness of 0.3 μm or less. 25. A molten metal plating apparatus comprising a sink roll and a support roll that rotate while being supported by bearings in molten metal, wherein at least one of the sink roll and the support roll is made of metal, and the shaft portion thereof A cylindrical ceramic sintered body whose outer periphery contains a solid lubricant is fitted, and the outer surface waviness of the sintered body is 0.3.
A continuous hot-dip metal plating device characterized by a plating thickness of μm or less.