JPH0230310A - Built-up roll using sleeve and device using above mentioned roll - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sleeve assembly type roll, and particularly to a sleeve assembly type roll suitable for use at high temperatures and equipment using the same.

[Conventional technology]

It is well known that it is effective to use materials with excellent corrosion resistance and wear resistance for the body and shaft portions of rolls used in high-temperature and corrosive environments. For example, a ceramic sleeve is fitted to the shaft of a roll used in an electrolytic plating tank (Japanese Patent Application Laid-Open No. 60-208626), and a ceramic sleeve is fitted to the body of a roll that conveys high-temperature materials. (Japanese Unexamined Patent Publication No. 61-55409).

[Problem to be solved by the invention]

When assembling the sleeve to the arbor,
No. 208626 describes that the sleeve is loosely fitted to the arbor, but there is no quantitative description, and it is unclear what the dimensional relationship between the sleeve and the arbor will be during use. Furthermore, in JP-A No. 61-55409, when cracks occur in the sleeve due to the difference in thermal expansion coefficient between the sleeve and the arbor, a different material such as metal is interposed between the sleeve and the taber as an expansion absorbing material. However, there is no mention of the stress generated in the sleeve, and the quantitative effect is unknown.

On the other hand, in order to prevent the sleeve from cracking, a structure has been proposed in which the sleeve is separated from the sleeve instead of being integrated into one body (Utility Model Applications No. 58-170156, No. 58-170157, No. 59-10958, No. 59-10958). No. 59-25360). Furthermore, a roll with a part of the surface made of ceramics has also been proposed (Utility Model Application Publication No. 58-152356, Utility Model Application Publication No. 1986-152-
No. 58560). However, if the sleeve is divided or a material with strong wear and corrosion resistance, such as ceramics, is used in parts, the gaps between them will corrode, making it impossible to fully achieve the purpose. In addition, discontinuities may occur and smooth rotation may not be obtained, which may adversely affect the product.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sleeve-assembled roll that does not apply stress to the sleeve when not in use and has a long life.

[Means to solve the problem]

As described above, various problems have occurred in the conventional technology. In order to solve these problems, the present invention has a single sleeve structure, and the sleeve and arbor are designed to have the necessary fitting force during operation.

In other words, select an appropriate interference so that the stress generated in the sleeve during operation is smaller than the strength of the sleeve material, and the sliding resistance is greater than the sliding force that acts between the arbor and the sleeve by driving the rolls. The object of the invention is thus achieved.

In the present invention, a sleeve is attached to an arbor, and the thermal expansion coefficient of the arbor is larger than that of the sleeve.
Moreover, in rolls used at high temperatures, the sleeve is characterized in that it has a gap between the sleeve and the taber when installed at room temperature, and eliminates the gap between the sleeve and the taber at the operating temperature so that the sleeve is in close contact with the arbor. It is in a prefabricated roll.

The present invention makes the circumferential stress generated on the inner circumferential surface of the sleeve at operating temperature smaller than the tensile stress of the sleeve material, and also smaller than the sliding force generated between the sleeve and the taber by driving the rolls. The radial dimensions of the sleeve and arbor must be accurately selected so as to increase the sliding resistance between the tabers.

Drill at least one hole in the radial direction of the sleeve and fix it to the arbor in a flexible structure using a bolt. Cut a groove in the end face of the sleeve and use a block to fix it in a flexible structure to the arbor. Both ends of the sleeve should be fixed to the arbor in a flexible structure. Flexible structure fixing is used to hold the sleeve to the arbor with flanges with a diameter larger than the diameter of the arbor.Flexible structure fixation is used to hold the sleeve to the arbor with flanges, hollow discs or blocks attached to both ends of the arbor.The arbor is made of metal and the sleeve is It is composed of a composite member of metal and ceramics or ceramics.

The sleeve assembly type roll in the present invention is used by keeping the sleeve and the arbor horizontal in the axial direction until the temperature at which the entire inner circumferential edge of the sleeve comes into contact with the arbor.

The sleeve assembly type roll of the present invention is used as a rolling roll in a rolling mill, a roll for conveying a heat-treated material in a heat treatment furnace, a sink roll in continuous hot-dip metal plating equipment, and the like.

[Effect]

FIG. 1 is a sectional view for explaining the present invention.

That is, there is a gap 3 between the arbor 1 and the sleeve 2 at room temperature. In the present invention, by controlling the gap 3, cracks do not occur in the sleeve, and furthermore, no burrs occur during movement between the sleeve and the arm.

Below, we will discuss how to determine an appropriate gap.

(1) When the temperature increases by ΔT, the diameter of the arbor is 2R
r'=(1+α1・ΔT) 2 Rt...(
1) where α1 is the linear expansion coefficient of the near bar R1: the radius of the arbor at room temperature (2) the diameter of the inner surface of the sleeve when the temperature increases by ΔT.

2Rz'=(1+α2・ΔT)2R2...(2) where α2 Linear expansion coefficient of the sleeve R2: Inner radius of the sleeve at room temperature (3) Gap between the arbor and the sleeve when the temperature increases by ΔT= δ= C2Rs'2R2' )-δo=2(axRz
-a2Rx) ΔT-δo - (3) Here, 60: If we set the gap between the arbor and the sleeve at room temperature as 2Ro = 2R1 = 2R2, then δ = 2 (αl-αz) Ro・ΔT-δo - (3) '
(4) Radial stress generated at the contact surface between the arbor and the sleeve Here: E1 Young's modulus of the near bar ν1 Poissonization of the near bar Ez Young's modulus of the sleeve ν2 Poisson's ratio of the sleeve R3: Outer radius of the sleeve at room temperature (5) Circumferential stress generated at the inner peripheral edge of the sleeve (6)
Condition σ1 for preventing the sleeve from cracking. 〈σB...(6
) Here, σB Tensile strength of the sleeve (7) Conditions for preventing slippage between the sleeve and the arm Tμp・2πRo−L−Ro Here, T: Torque μ The sliding friction coefficient between the near bar and the sleeve L of the sleeve length, that is, the gap δo between the sleeve and the arm at room temperature so as to satisfy equations (6) and (7) at the operating temperature.
By determining =2 (R1-R2), it is possible to obtain a sleeve assembly type roll in which cracks do not occur in the sleeve and slippage does not occur between the sleeve and the arm.

〔Example〕

[Example 1] Fig. 2 shows a sleeve assembly type roll manufactured according to the present invention. Arbor 1 uses JIS standard SCM 440
H steel (chromium molybdenum steel) is heated to 850°C and then oil quenched.

The material used was tempered at a temperature of 550° C. and had a Vickers hardness of 360. Also, the sleeve has S
A β-sialon ceramic sintered body of ie-zA Q zozNa-z was used. 2 is O~4.2. The hardness is 1800 Vickers hardness and has excellent wear resistance, about 1
It is a material with no decrease in hardness up to 000'C.

This roll is used for rolling difficult-to-process materials such as W and Mo at a temperature of about 450 m.

Hereinafter, a method for assembling a sleeve according to the present invention will be described quantitatively.

The dimensions of the arbor are the outer diameter (2Rz) of 160m and the total length of 5.
50mm, sleeve dimensions are inner diameter (2Rz) 160.
5nn, outer diameter (2Ra) of 200m, length (L) of 30
It was set to 0 mm. Further, the linear expansion coefficient, Young's modulus, and Poisson's ratio of the arbor and sleeve are as follows.

αt=12X10-6/℃ αz=3.2×10-6/℃ E1=2, I×10'kg/an2Ez
=3. lX10'kg/aa2 vr=yz=0.28 Furthermore, the sliding friction coefficient (μ) between the arbor and the sleeve is 0.15 from experimental results. In addition, the tensile strength (σB) of Sialon ceramics used for the sleeve is 40 kg.
/nuz. ΔT at the operating temperature of the roll from the operating conditions
is 450℃, torque (T) is 2.5 x 10'kg-
It is m.

By substituting these values into equations (3)', (4), and (5), the gap (δ) between the arbor and sleeve at room temperature can be calculated.
The third
Shown in the figure. Furthermore, the range of δ0 according to the present invention is shown in FIG. 3 under the conditions shown in Equation 1 (6) and Equation (7). Third
As shown in the figure, 60 may be selected within the range of 0.363<60<0.6296 m, but in this embodiment, δo'' is set to 0.5 mm.

Substituting δo = 0.5m into equation (3)', the interference during operation becomes δ = 0.13mm, and the contact stress between the arbor and sleeve is calculated from equation (4) as p = 4.28kg/
臘2. The stress in the circumferential direction on the inner circumferential edge of the sleeve is calculated from equation (5) by c
r tt = 19, 5 kg/cr2.

Therefore, the slip resistance is obtained from equation (7) with p>0.0
14kg/mm", and the cracking limit of the sleeve cr tt < cra = 40 kg/
σ and 1 are approximately 1/2 of l11112, and both values are safe.

To assemble the sleeve to the arbor, form a flange with a larger outer diameter than the body at one end of the body of the arbor, fit the sleeve at room temperature, and then attach a hollow disk with a diameter larger than the body to the other end. The flexible structure was fixed by bolting to the arbor. Although a hollow disk was used in this embodiment, blocks may be used instead of the hollow disk and partially fixed to the arbor.

The rolls assembled in this manner at room temperature were assembled into a rolling mill, and the entire rolling mill was heated to 450° C. while keeping the rolls horizontal. The heating time was long enough for both the arbor and sleeve to reach 450°C. Next, tungsten was rolled while keeping the entire roll at 450°C. the result.

There is no cracking of the sleeve or slippage between the arbor and the sleeve, and the roll speed is 20% lower than that of conventional high-speed steel rolls.
We were able to achieve a lifespan that is more than 0 times longer.

[Example 2] In Example 1, Sialon ceramics was used as the sleeve material, but in this example, WC-T, a type of cemented carbide, was used.
The results of applying the i C-T a C-Co sintered alloy (JISKIO equivalent product) will be described.

The coefficient of linear expansion, Young's modulus, and Poisson's ratio of this material are as follows.

αz=5.5X10-'/"C Ez=5.7 X 10'kg/nwm"乍2=0.2
2 Furthermore, the coefficient of slippage friction with steel was experimentally determined to be μ=0.17. Further, the tensile strength (σB) of the sleeve material was 125 kg/m2. The operating temperature and rolling torque are the same as in Example 1.

Arbor dimensions are outer diameter (2R1) 160mm, total length 550mm, sleeve dimensions are inner diameter (2Rz) 1160mm.
．． 3nn, outer diameter (2R3) of 200mm, and length (L) of 300n+n+.

Substituting these values into equations (3)', (4), and (5), the interference during operation is δ = 0.17 nya, the contact stress between the arbor and the sleeve is p = 9.0 kg/in2, and the inside of the sleeve is The circumferential stress at the periphery is σtt = 41, 7
kg/a2. Therefore, the slipping resistance is about 650 times the slipping force generated by torque, which is sufficiently large, and the safety factor against cracking of the sleeve is about 3.

To assemble the sleeve to the arbor, a flange is machined at one end of the body of the arbor, and two grooves are machined at one end of the sleeve, 20an in the circumferential direction and 5m in the axial direction, 180 degrees apart. The flexible structure assembly was carried out in the same manner as in Example 1, in which the blocks were bolted together using bolts.

The rolls assembled in this manner at room temperature were assembled into a rolling mill, and the entire rolling mill was heated to 450° C. while keeping the rolls horizontal. The heating time was long enough for both the arbor and sleeve to reach 450°C. Next, tungsten was rolled while keeping the entire roll at 450°C.

As a result, there were no cracks in the sleeve or slippage between the arbor and the sleeve, and the roll life was approximately four times longer than that of conventional rolls using high-speed steel.

[Example 3] Metals are subjected to various heat treatments during the manufacturing process to give them the required dimensions and properties. The temperature is 10 depending on the purpose
The treatment ranges widely from high temperatures of 00"C or higher to sub-zero treatments of 0C or lower. As a third embodiment of the present invention, the results of application to a roll used in a high-temperature heat treatment furnace will be described.

The roll dimensions are 160am in diameter and 700m in length.
It is. The roll is driven by a chain and is used in a continuous bright annealing furnace where the product is fed over the roll, and the roll temperature during operation is 920°C. Conventionally, Cr11. Ni-Cr steel or Ni-Cr-C
Heat-resistant steel such as o-based alloys was used, but oxidation, corrosion,
Transformations were often necessary due to deformation, alteration, etc.

Therefore, an attempt was made to assemble a ceramic sleeve to a steel arbor using the method of the present invention. The outer diameter (2Ra) of the sleeve is 160mm, the inner diameter (2R2) is 141,
Qma, the length (L) is 7ΦOIm, the outer diameter of the arbor (2R work) is 140 kan, and the total length is I C) OO fan.

The material of the sleeve was the sialon ceramic sintered body described in Example 1, and the material of the arbor was N.
i-Cr steel was used.

The interference at the operating temperature is δ" 0.137 mm, the contact stress between the arbor and the sleeve is p = 3.33 kg/m2. The circumferential stress generated at the inner peripheral edge of the sleeve is σtc = 2.
5.8 kg/mea2. The sliding force generated by the torque applied to the roll is sufficiently small compared to the sliding resistance and can be ignored. Further, the stress generated in the sleeve is small compared to the strength of the sleeve, so there is no problem.

Next, we will explain how to assemble the sleeve to the arbor.One sleeve was machined to the specified dimensions without any processing necessary for assembly.A flange with an outer diameter of 200 mm and a thickness of 30+ m was attached to one side of the arbor, and a flange was attached to the other side. After cutting the threads and assembling the sleeve into the arbor at room temperature, the outer diameter is 20 mm.
It was fixed with a 30m thick female screw. The rolls thus assembled were placed in the above-mentioned furnace, and after the temperature of the sleeve and arbor reached 920°C, continuous annealing was started. After one week of continuous work,
As a result of extracting the roll from the furnace and investigating the surface condition, no cracks were observed and there was no change at all from the state in which it was assembled. On the other hand, scratches and wear were observed on the Ni-Cr steel roll, confirming the effectiveness of the sleeve-type roll assembled by the method of the present invention.

Further, the sleeve-type roll according to the present invention can also be used as a roll for continuous casting or various rolls for conveying high-temperature materials.

[Example 4] The sink roll and support roll used in the continuous hot-dip metal plating bath shown in FIG. 5, particularly in the zinc or aluminum bath, are required to have corrosion resistance and wear resistance.

Conventionally, materials such as stainless steel and high chromium steel have been used in the form of overlays or sleeves. However, when these materials are used for a long period of time, corrosion and wear occur, making it necessary to replace the rolls. That is, the surface of the body of the roll becomes rough due to the erosion effect of the molten metal, which impairs the uniformity of plating. In addition, due to erosion caused by molten metal and abrasion damage caused by the load, the roll shaft becomes thinner and looseness occurs between the shaft and the bearing.
This may cause vibration and uneven bonding thickness.

This example describes the results of applying the method of the present invention to a sink roll for continuous hot-dip metal plating.

FIG. 4 shows a cross section of a roll according to the invention. Sunaochi,
It has a structure in which a sleeve 7.8 having excellent corrosion resistance and wear resistance is assembled on the surface of the roll shaft 4 and cylinder 5.

The manufacturing method of this roll will be described below. The diameter of shaft 4 is 1
30m5, length is 180an, outer diameter of shaft sleeve 7 is 1
50mm, inner diameter is 130.6 nm, length is 180mm
It is. Further, the diameter of the body 5 is 420 nm.

Length is 1160I excluding flange 6 and retaining ring 9
, the outer diameter of the trunk sleeve 8 is 450+m, the inner diameter is 422mm,
The length is 1160ai.

The material is axis 4. Copper 5, flange 6 and retaining ring 9 are made of Ni.
-Cr-Mo1l, also shaft sleeve 7 and trunk sleeve 8
was the sialon ceramic sintered body shown in Example 1.

JIS symbol for Ni-Cr-Mo steel is SNCM44.
No. 7 was selected and the heat treatment was performed by quenching in oil from 850'C and then tempering at 670C to achieve a Brinell hardness (Ha) of 320. It was then machined to the desired dimensions.

Sialon ceramics were formed into compacts by cold isostatic pressing, rough-processed leaving firing shrinkage and finishing allowance, fired at 1750° C., and then finished into predetermined dimensions.

As for assembly, first, the trunk sleeve 8 was inserted into the trunk 5 at room temperature and fitted with a gap, and then the retaining ring 9 was fixed to the flexible structure with screws 10. Next, after fitting the shaft sleeve 7 onto the shaft 5 at room temperature with a clearance, the hole 11 made in the shaft sleeve 7 is
A flexible structure was fixed to the shaft 5 using bolts through the shaft.

The usage conditions for this roll are for continuous use in aluminum plating at 650°C, and the gap between the arbor and sleeve at room temperature is (3)' when both the arbor and sleeve reach 650°C. (4) and (
It is determined that the value obtained from equation 5) satisfies equations (6) and (7). In other words, the shaft sleeve length is δ
=O, 145m, p=4.02kg/m'', σ
−t = 29, 2 kg/m”, for the trunk sleeve δ = 0.408 ma+, p = 1.84 kg/m
a+”.

σt+=27.7 kg/no”.

Evaluation of the present invention will be described below. As a result of using the sink roll manufactured according to the present invention for continuous plating work in an aluminum bath at 650°C, the shaft of the conventional gold am roll had severe wear and the roll had to be replaced every 4 days, but the present invention Even after using the roll for two consecutive months, there was no abnormal wear, the amount of wear was small, and uniform plating work was achieved. Moreover, no cracks or deviations occurred in the sleeve, and it was confirmed that the assembly method according to the present invention can effectively utilize the ceramic sleeve.

〔Effect of the invention〕

According to the present invention, in a sleeve assembly type roll used at high temperatures, an appropriate interference can be provided at the operating temperature even when the thermal expansion coefficient of the sleeve is smaller than that of the arbor. Therefore, a sleeve made of ceramics, which is a brittle material that is weak against tensile stress, can be effectively utilized. Ceramics have high-temperature strength, wear resistance, and corrosion resistance, so
As a roll for hot rolling, heat treatment furnaces, and hot-dip metal plating, it has a much longer lifespan than conventional metal rolls. Further, a sleeve made of cemented carbide, which is a cermet made of metal and ceramics, can be used at temperatures up to about 500'C, and a long life can be obtained.

Therefore, the sleeve assembly type roll according to the present invention is effective in improving productivity, reducing product cost, and improving quality.

[Brief explanation of the drawing]

FIG. 1 is a sectional view for explaining the present invention in detail, FIG. 2 is a perspective view of a rolling roll showing an embodiment of the present invention, and FIG.
The figure is an explanatory diagram showing the scope of the present invention according to one embodiment, FIG. 4 is a sectional view of a hot-dip metal plating roll showing another embodiment of the present invention, and FIG. 5 is a continuous molten metal. Light 30 Wood 4 Eyes Book 1 Figure 2 - Figure

Claims (1)

[Claims] 1. In a roll in which a sleeve is attached to an arbor, the coefficient of thermal expansion of the arbor is greater than that of the sleeve, and the roll is used at high temperatures, the gap between the sleeve and the arbor when attached at room temperature. A sleeve assembly type roll having a gap between the sleeve and the arbor, which is characterized by eliminating the gap between the sleeve and the arbor at the operating temperature and allowing the sleeve to adhere to the arbor. 2. The circumferential stress generated on the inner peripheral surface of the sleeve at the operating temperature is smaller than the tensile stress of the sleeve material, and the stress between the sleeve and arbor is smaller than the sliding force generated between the sleeve and arbor by driving the rolls. The sleeve assembly type roll according to claim 1, wherein the radial dimensions of the sleeve and the arbor are selected so as to increase the sliding resistance. 3. Drill at least one hole in the radial direction of the sleeve,
The sleeve assembly type roll according to claim 1 or 2, characterized in that the sleeve assembly type roll is fixed to the arbor in a flexible structure via bolts. 4. The sleeve assembly type roll according to any one of claims 1 to 3, wherein a groove is cut in the end face of the sleeve and the sleeve is fixed to the arbor in a flexible structure using a block. 5. The sleeve assembly type roll according to any one of claims 1 to 4, wherein both ends of the sleeve are fixed in a flexible structure held by flanges having a diameter larger than the diameter of the arbor. 6. The sleeve assembly type roll according to claim 5, characterized in that the flexible structure for holding the sleeve to the arbor is fixed by flanges, hollow disks or blocks attached to both ends of the arbor. 7. The sleeve assembly type roll according to claim 6, wherein the arbor is made of metal and the sleeve is made of ceramic. 8. The sleeve assembly type roll according to any one of claims 1 to 7, wherein the arbor is made of metal and the sleeve is made of cemented carbide made of a composite member of metal and ceramics. 9. A method of using a sleeve assembly type roll according to any one of claims 1 to 8, characterized in that the axial direction of the sleeve and the arbor are kept horizontal until the temperature at which the entire inner peripheral edge of the sleeve comes into contact with the arbor. 10. A rolling mill characterized in that the sleeve type assembly roll according to any one of claims 1 to 8 is used as a rolling roll. 11. A heat treatment furnace, characterized in that the sleeve-type assembly roll according to any one of claims 1 to 8 is used as a roll for conveying an object to be heat treated. 12. Continuous molten metal plating equipment, characterized in that the sleeve type assembly roll according to any one of claims 1 to 8 is used as a sink roll.