JPH1019552A - Shape sensor roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a sleeve 12 which is used by shrink-fitting a core shaft 20 of a shape sensor roll 10 so as to bend when subjected to a load of a rolled material so as to bend when subjected to a load of a rolled material. Provided is a sleeve capable of eliminating or simplifying a straightening operation during a process. SOLUTION: A sleeve 12 is formed by sintering a high-speed metal powder by hot isostatic pressing, and after the entire sleeve 12 is annealed, only the outer surface side of the sleeve is subjected to high frequency induction heating. Hardened and hardened. The outer surface of the sleeve has a surface hardness of Hs 65 to 90, and the inner surface has a surface hardness of Hs 55 to 65.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape sensor roll which is arranged at least on one side of a rolling mill, particularly a hot rolling line, on an inlet side or an outlet side, and detects a shape of a rolled material to be rolled. It is.

[0002]

2. Description of the Related Art It is important to ensure a uniform shape of a rolled material rolled by a hot rolling mill in a hot rolling line in order to ensure product quality. In this case, since the shape change of the rolled material cannot be visually determined while the rolled material is running, the shape of the running rolled material is inspected by the shape detecting device.

As shown in FIG. 5, this shape detecting device detects the tension of each part in the width direction of a rolled material (30) on a looper roll provided between finishing rolling stands (32) arranged in a line direction. The roll is a shape sensor roll (10) incorporating a detector configured as described above, and the shape of the rolled material is detected by measuring the tension distribution in the width direction of the rolled material (30).

Conventionally, as this shape sensor roll, there is a roll adopting a hollow split roll method as shown in Japanese Utility Model Publication No. 3-11691. As shown in FIGS. 6 and 7, a plurality of rotors (42) divided in the axial direction are fitted around the outer periphery of a hollow fixed shaft (40), and the fixed shaft is
A nozzle (44) for supplying compressed air from the hollow portion to the gap between the fixed shaft (40) and the rotor (42) is provided on the peripheral wall of the (40).
(40) are bored so as to be located at predetermined intervals in the axial direction and the circumferential direction, and furthermore, detection for air pressure measurement which is communicated with a detection pipe (46) at the upper and lower peripheral wall portions of the fixed shaft (40). A port (48) is provided, and the pressure difference of the air generated when the rotor (42) is displaced with respect to the fixed shaft is detected from the upper and lower detection ports (48) through the detection pipe (46), and the detected pressure difference of the air is detected. Is converted by the static electricity converter (50), and the tension distribution in the width direction of the rolled material (30) is obtained by an arithmetic unit (not shown).

Further, as shown in Japanese Utility Model Publication No. 3-11692, a rotatable shaft is used in place of a fixed shaft, and sensors are embedded in the outer peripheral surface of the shaft so as to correspond to each rotor. In some cases, the tension distribution in the width direction of the rolled material can be measured based on the value detected in (1).

[0006]

However, in the case of these conventional shape sensor rolls, the rotor on the roll surface has an axially multi-divided structure. Therefore, when the tension of the rolled material becomes high, the divided portions of the rotor are divided. Therefore, there is a possibility that the rolled material may be damaged.

For this reason, the applicant has considered using a sleeve having an axially integrated structure instead of the rotor having a multi-split structure. As shown in FIGS. 2 and 4, a shape sensor roll (10) using the sleeve (12) having the axially integral structure has a cutout portion parallel to the axis at a part of the outer periphery of the core shaft (20). (22) is formed, and the detecting portion (28) slightly protrudes from the surface of the notch (22) at a predetermined interval in the axial direction of the core shaft in the notch (22). A sensor (26), a sleeve (12) is fitted around the outer periphery of the core shaft (20), and a gap (22) is formed between the sleeve (12) and the cutout portion (22) of the core shaft (20). 24) is formed. The sleeve (12) bends into the gap (24) when subjected to the load of the rolled material (30), so the amount of bending deformation of the sleeve is detected by the sensor (26), and the tension distribution in the width direction of the rolled material is detected. Can be detected.

The sleeve has, for example, an outer diameter of about 190 mm,
Although it is a hollow tube with a length of about 2000 mm, to obtain the desired sensitivity with the sensor, the wall thickness must be thin (usually about 10 m).
m or less) so that appropriate bending deformation occurs. When this thin-walled sleeve is produced by casting, there is a problem that cracks are likely to occur from the porosity as a starting point when the sleeve is fitted to the core shaft by shrink fitting due to the existence of porosity peculiar to the cast product.

In the case of a shape sensor roll used in a hot rolling line, the sleeve is formed of a material having heat resistance, abrasion resistance, corrosion resistance, high strength, etc., because it comes into contact with a high-temperature rolled material. I have to. However, when the sleeve is fitted to the core shaft by shrink fitting,
Since a large residual stress remains after shrink fitting, it is desirable that the inner surface side of the sleeve has excellent toughness.

Therefore, as shown in FIG. 4, the applicant made the inner layer (14) a SCM440 steel pipe having excellent toughness,
A high-speed metal powder having excellent heat resistance, abrasion resistance, etc. is coated on the outside of the inner layer (14) by HIP (hot isostatic pressing).
As (18), a two-layered sleeve (12) coated and applied was proposed (Japanese Patent Application No. 6-337425). However, in the production of the sleeve, bending deformation occurs due to a difference in cooling rate depending on the position of the sleeve at the time of cooling after HIP sintering or at the time of cooling by quenching heat treatment. In the case of the sleeve, the thickness of the outer layer and the inner layer varies, and the amount of deflection of the sleeve with respect to the rolling load varies, which may adversely affect the measurement accuracy of the sensor. For this reason, it is necessary to perform a bending correction operation to a state close to a perfect circle before cutting or grinding, and the operation requires a large number of man-hours.

An object of the present invention is to provide a sleeve which is shrink-fitted to a shape sensor roll and which can omit or simplify a bending correcting operation during a manufacturing process.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a sleeve made of a single material, and by devising a heat treatment, the outer surface of the sleeve has high wear resistance and the inner surface has a high wear resistance. It has high toughness. The sleeve was formed by sintering high-speed metal powder by hot isostatic pressing to form a cylinder, annealing the entire sleeve, and then applying only the frequency 1 to the outer surface of the sleeve.
Hardened and hardened by induction heating at 10 kHz.

The outer surface of the sleeve has a surface hardness of Hs 65-
Hs is preferably 90 to 85. The surface hardness of the inner surface is set to Hs 55 to 65, and preferably Hs 55 to 60.

[0014] The high-speed metal powder is preferably prepared by a rapid solidification method. The reason is that crystal grains are refined, and rapid cooling and solidification methods include an atomizing method, a melt spinning method, and a melt extraction method.

[0015]

Since the sleeve is formed by HIP, it is very dense and has no porosity unlike a cast product. Although the sleeve is made of a single material, the inner surface side has low hardness and excellent toughness, and does not generate cracks etc. at the time of shrink fitting of the sleeve to the core shaft, It can be integrally attached, and can sufficiently cope with a reduction in the thickness of the sleeve. Further, the outer surface side of the sleeve is high in hardness and excellent in wear resistance, so that the life of the shape roll sensor can be extended.

[0016]

1 and 2 show an embodiment of a shape sensor roll according to the present invention. Shape sensor roll (10)
Has a hollow core shaft (20) rotatably supported by bearings (not shown) at both shaft ends. The core shaft (20) has a cutout (22) having a flat surface parallel to the axial direction at a part of the outer periphery. Holes are formed at predetermined intervals in the notch portion (22), and a sensor (26) is embedded in each hole. The sensor may be a load cell. The sensor (26) has the detection unit (28) slightly projecting from the flat surface, and when a force is applied to the detection unit, a detection value is output according to the force and transmitted to the detector. it can.
When a load cell is used as a sensor, a voltage corresponding to a force is generated and measured by a detector.

The sleeve (12) is a hollow thin-walled cylindrical body, the inner diameter of which is slightly smaller than the outer diameter of the core shaft, which is shrink-fitted to the core shaft (20) to be integral with the shape sensor roll (10). Configure. Although the illustrated core shaft is hollow, it may be solid if there is a hole for passing the sensor wiring.

The sleeve 12 is formed by sintering a high-speed metal powder by hot isostatic pressing (HIP). The HIP process is typically performed at a temperature of 1000-120.
The reaction is performed at 0 ° C., a gas pressure of 1000 to 1200 kgf / cm ² , and a time of ² to 3 hours. As a high-speed metal forming the sleeve, for example, C: 1.0% by weight.
２2.4%, Si: 0.6% or less, Mn: 0.6% or less,
Cr: 0.5 to 20%, 2Mo + W: 1.5 to 45%,
At least one of V, Ti, Nb, and Ta in total
12%, Ni: 3.0% or less as required, and the balance substantially consisting of Fe. In addition, C: 1.4 to 2.4%, Si: 0.4%
2 to 1.5%, Mn: 0.2 to 1.0%, Cr: 10 to 1
8%, Mo: 0.5 to 1.0%, V: 6% or less, with the balance substantially consisting of Fe.

The sleeve made by HIP is subjected to annealing, cutting, heat treatment of quenching and tempering, and cutting.
Through (grinding) processing, the inner diameter is finished to be slightly smaller than the outer diameter of the core shaft so that it can be shrink-fitted to the core shaft of the roll, but as described above, cooling after HIP sintering At the time of cooling during quenching, bending deformation occurs due to a difference in cooling rate at the position of the sleeve. However, the sleeve of the present invention is made of a single material, and it is not necessary to consider the variation in the thickness of the outer layer and the inner layer unlike the sleeve of the two-layer structure, so that the cutting allowance or the grinding allowance is within the design range. As long as there is some bending deformation, cutting or grinding can be performed immediately without performing bending correction work. If the bending deformation is so large that it exceeds the design range of the cutting allowance or grinding allowance, the bending correction work is performed, but even in that case, it is not necessary to correct it to a state close to a perfect circle like a two-layer sleeve, The task is very easy.

[0020]

EXAMPLE Fabrication of sleeve High-speed metal (1.3% by weight, 0.3% of Si,
Mn 0.3%, Cr 4.0%, Mo 5.0%, V 4.0%,
Atomized powder (W 6.0%, Fe balance) was HIPed in a HIP device to form a 15 mm thick sleeve by sintering. HIP conditions are 1100 ° C temperature, 1100kgf
/ Cm ² for 3 hours. The obtained sleeve is
After annealing (850 ° C. × 2 hours), quenching was performed by high frequency induction heating at 1180 ° C. and a frequency of 10 kHz.
Tempering treatment of heating and holding at 0 ° C. for 10 hours and allowing to cool was performed three times.

Hardness Measurement The hardness distribution in the radial direction of the test sleeve was measured. In addition,
The sleeve is machined after tempering and has a thickness of 9 mm.
, And the hardness measurement was performed on the finished sleeve. FIG. 3 shows the measurement results. The outer surface has a hardness of Hs70, and exhibits excellent wear resistance when brought into contact with a rolled material. Further, the hardness decreases substantially proportionally toward the inner surface, and the hardness on the inner surface is Hs5.
It is 8. By forming a hardness gradient in the radial direction of the sleeve in this manner, strength and toughness are imparted to the entire sleeve.

Measurement of Mechanical Properties Since the sleeve of the present invention is a thin and long tube, it is difficult to directly determine mechanical properties such as tensile strength and elongation. For this purpose, a capsule of 60 mm in diameter and 60 mm in length is filled with a powder of high-speed metal, and this is HIPed to produce a sintered body, and the obtained sintered body is subjected to an appropriate heat treatment to form a sleeve. A test piece having the same hardness as the outer surface and the inner surface was prepared. Test No. 1 is a test piece that has been quenched and tempered, has a hardness of Hs76, and corresponds to the outer surface side of the sleeve (hardness Hs 65 to 90). Test
No. 2 was annealed and had a hardness of Hs57.
And a test piece corresponding to the inner surface side (hardness Hs 55 to 65) of the sleeve. Test No. 3 is a test piece as-HIPed, not subjected to annealing, quenching and tempering, and has a hardness of Hs64. For these three types of test pieces, the tensile strength, elongation, and mechanical properties of the drawing were measured. Table 1 shows the results.

[0023]

[Table 1]

Referring to Table 1, the test piece of No. 1 corresponding to the outer surface side of the sleeve has a large tensile strength, and the test piece of No. 2 corresponding to the inner surface side of the sleeve has a large elongation and a large drawing. It is presumed that the sleeve of the present invention is good in strength and toughness. When No. 2 and No. 3 are compared, it is found that the hardness of No. 2 is reduced by the annealing treatment, the elongation and the drawing are improved, and the toughness is improved as compared with No. 3. . This may be because the annealing reduces the residual stress and homogenizes the structure.

[0025]

According to the shape sensor roll of the present invention, since the sleeve is formed by HIP, it is very dense. Also, despite being formed of a single material, a hardness gradient is formed in the radial direction, the outer surface side has abrasion resistance,
The inner surface is excellent in toughness, and can be integrally attached to the core shaft without causing cracks or the like when shrink-fitting the sleeve to the core shaft, which can sufficiently cope with a reduction in the thickness of the sleeve. Therefore, the shape sensor roll of the present invention can obtain high reliability over a long period of time for detecting the shape of a rolled material in a hot rolling line.

[Brief description of the drawings]

FIG. 1 is a sectional view of a shape sensor roll of the present invention.

FIG. 2 is a perspective view of a shape sensor roll.

FIG. 3 is a graph showing a relationship between a layer thickness and a hardness of a sleeve.

FIG. 4 is a sectional view of a shape sensor roll provided with a sleeve having a two-layer structure.

FIG. 5 is a schematic view of a rolling stand.

FIG. 6 is a perspective view of a conventional shape sensor roll.

FIG. 7 is a cross-sectional view of a conventional shape sensor roll.

[Explanation of symbols]

 (10) Shape sensor roll (12) Sleeve (20) Core shaft

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hajime Ishii 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawashima-Harima Heavy Industries, Ltd. Yokohama Engineering Center (72) Inventor Hideo Fujita Nakamiya Oike, Hirakata-shi, Osaka 1-1-1 1-1 Kubota Hirakata Plant (72) Inventor Yoshio Katayama 1-1-1 Nakamiya Oike 1-1 Hirakata City, Hirakata City, Osaka Prefecture Kubota Hirakata Plant

Claims (3)

[Claims] 1. A notch (22) in a part of the outer periphery parallel to the axis.
A core shaft (20), a sensor (26) arranged at a predetermined interval in the notch at an axial direction, and a cylindrical sleeve (12) shrink-fitted to the core shaft. A gap (24) is formed between the sleeve (12) and the notch (22) of the core shaft (20),
By measuring the deflection generated when the sleeve (12) receives the load of the rolled material (30) with the sensor (26), the rolled material (30)
A shape sensor roll adapted to detect the shape of the sleeve, wherein the sleeve (12) is formed by sintering a high-speed metal powder by hot isostatic pressing, and the entire sleeve (12) is annealed. After being treated, only the outer surface of the sleeve is quenched and hardened by high-frequency induction heating. 2. The sleeve (12) has a surface hardness of Hs 65-90 on the outer surface side and a surface hardness of Hs 55-90 on the inner surface side.
The shape sensor roll according to claim 1, wherein the number is 65. 3. The shape sensor roll according to claim 1, wherein the high-speed metal powder is a powder prepared by a rapid solidification method.