JPH11269558A - Chill roll for metal strip - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To ensure more uniform cooling of a metal strip in the width direction of the metal strip, and to use the metal strip with excellent durability and stable for a long period of time without causing deterioration of the shape or flaws in the metal strip. The present invention provides a cooling roll for a metal strip which can be manufactured at a low cost. SOLUTION: In a cooling roll 1 of a metal strip 5 having a cooling medium flow passage therein, a soft layer 3 having high thermal conductivity is provided on an outer peripheral surface of the cooling roll 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling roll used in a surface treatment or a heat treatment step of a metal strip such as a steel strip or a stainless steel strip, and more particularly to a cooling roll capable of uniformly cooling a metal strip in a width direction. Things.

[0002]

2. Description of the Related Art Conventionally, in a continuous annealing process of a metal strip, for example, a steel strip, when a heating zone or a steel strip heated and soaked in a soaking zone is primarily cooled, a cooling pipe is provided inside the cooling pipe. There was a method in which a steel strip was wound around a roll and cooled while passing the steel strip. In this conventional cooling method, in order to rapidly cool the steel strip while passing the steel strip, it is necessary to improve the contact state between the cooling roll and the steel strip and cool the steel strip uniformly.

For this reason, for example, Japanese Patent Application Laid-Open No. Hei 2-19042
In the technology described in Japanese Patent Application Laid-Open No. 5 (1993) -1995, a plurality of circumferential grooves having a depth of 10 to 100 μm, a width of 以下 of the pitch and a rectangular cross section are provided on the outer surface of the water-cooled roll in the roll axial direction. Are known. In the technology described in this publication, since the ridges formed along the groove are continuous, the durability is excellent, and the cooling efficiency is improved by ensuring the contact with the steel strip for a long period of time. I can do it.

[0004]

However, in the above-mentioned prior art, since the cooling heat transfer from the ridge is larger than that of other portions, the contact portion of the ridge and the non-contact portion (groove) are not provided. ), The temperature difference increases, the uniformity of cooling is impaired, and the shape of the steel strip is likely to be deteriorated. Further, it is difficult to uniformly cool a steel plate having a poor shape. Furthermore, with the recent technological innovation, it is expected that the surface treatment or heat treatment process of the metal strip will be further accelerated,
In response to such speeding-up, development of a cooling roll capable of increasing cooling efficiency and ensuring sufficient cooling uniformity has been desired.

The present invention has been proposed in view of the above-mentioned circumstances, and is a cooling roll used in a surface treatment or heat treatment process of a metal strip, which ensures more uniform cooling of the metal strip in a sheet width direction. In addition, an object of the present invention is to provide a metal strip cooling roll that is excellent in durability, can be used stably for a long period of time, and is inexpensive, without causing deterioration in shape and scratches on the metal strip.

[0006]

Means for Solving the Problems (Features) The present invention has the following features in order to achieve the above object. The invention according to claim 1 is characterized in that, in a cooling roll of a metal strip having a cooling medium passage therein, a soft layer having high thermal conductivity is provided on an outer peripheral surface of the cooling roll. According to a second aspect of the present invention, in addition to the features of the first aspect, the soft layer has a thermal conductivity of 10 W / mK or more and an apparent Young's modulus of 0.01 to 0.01.
10 kg / mm ² , 10 to 1 of apparent Young's modulus
000 times.

According to a third aspect of the present invention, in addition to the features of the first or second aspect of the present invention, the soft layer is formed by including a high thermal conductive fiber in a soft rubber. It is assumed that. According to a fourth aspect of the present invention, in addition to the features of the first or second aspect of the present invention, a fiber material made of a high heat conductive fiber is provided as the soft layer. According to a fifth aspect of the present invention, in addition to the features of the fourth aspect, the fibrous material is disposed so as to be inclined in a circumferential direction of the cooling roll.

(Operation) The present invention has the above-described configuration, and thus has the following operation. According to the first aspect of the invention, when the metal strip passes while contacting the outer peripheral surface of the cooling roll, it is cooled by the cooling medium flowing through the flow passage provided inside the cooling roll. At this time, the metal strip is uniformly adhered to the roll in the width direction and efficiently cooled by the soft layer having high thermal conductivity interposed between the metal strip and the cooling roll. For this reason, the metal strip is uniformly cooled in the width direction of the plate, and the shape is not deteriorated and no flaw is generated. According to the second aspect of the invention, the surface of the cooling roll can be sufficiently cooled by setting the thermal conductivity of the soft layer to 10 W / mK. Further, by setting the apparent Young's modulus of the soft layer in the range of 0.01 to 10 kg / mm ² and the thickness in the range of 10 to 1000 times the apparent Young's modulus, the flexibility of the soft layer can be maintained. In addition, since the metal strip comes into uniform contact with the metal strip, the shape is not deteriorated, and no flaw is generated on the surface of the metal strip.

According to the third aspect of the present invention, the heat conductivity between the metal strip and the cooling roll can be obtained by the high heat conductive fibers contained in the soft rubber constituting the soft layer, and
The flexibility of the rubber makes the cooling of the metal strip in the width direction more uniform. In the invention according to claim 4,
The heat conductivity between the metal strip and the cooling roll is further enhanced by the fibrous material made of the high heat conductive fiber disposed as the soft layer, and the cooling in the width direction of the metal strip becomes more uniform. According to the fifth aspect of the present invention, since the fiber material is inclined in the circumferential direction of the cooling roll, the apparent Young's modulus of the fiber material is reduced, and the flexibility of the soft layer is not impaired.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 4 show a cooling roll of a metal strip according to the present invention. FIG. 1 is a cross-sectional view of the cooling roll, and FIGS. 2 and 3 show high heat conductive fibers arranged in a brush shape as a soft layer. FIG. 4 is an explanatory view showing an example of the arrangement of cooling rolls.

A cooling roll 1 according to the present invention is used for cooling a metal strip 5 in a continuous heat treatment step. As shown in FIG. 1, a soft layer 3 is formed on a peripheral surface of a roll body 2 made of an iron core. And a cooling pipe 4 for circulating a cooling medium inside the soft layer 3 is provided. Although not shown, a cooling medium is circulated in the cooling pipe 4 by a cooling medium supply device, and the metal strip 5 can be cooled via the soft layer 3 by the action of the cooling medium. When the cooling rolls 1 are used in a continuous heat treatment step, as shown in FIG. 4, a plurality of cooling rolls 1 are arranged at predetermined intervals, and a metal strip 5 is wound around the outer peripheral surface of each cooling roll 1. And the metal strip 5 is cooled.

The soft layer 3 has a thermal conductivity of 10 W / mK.
As described above, the apparent Young's modulus is 0.01 to 10 kg / m.
It is preferable that m ² and the thickness are 10 to 1000 times the apparent Young's modulus. That is, the thermal conductivity is 10 W / mK
If it is less than the above, the surface of the cooling roll 1 cannot be sufficiently cooled. The apparent Young's modulus is 0.01 to
When the thickness exceeds the range of 10 kg / mm ² or the thickness exceeds the range of 10 to 1000 times the apparent Young's modulus, the flexibility cannot be maintained, and the shape of the metal strip 5 deteriorates. Or a flaw occurs on the surface of the metal strip 5. The soft layer 3 is made of, for example, styrene-butadiene rubber (SBR), nitrile rubber (NB
R) and other soft rubbers with polybenzobisoxazole (P
(BO) fiber, carbon fiber, nickel, chromium fiber and the like.

When the high thermal conductive fibers are arranged in a brush shape as the soft layer 3, as shown in FIG.
A fiber material 6 made of high heat conductive fiber is disposed to be inclined in the circumferential direction of the cooling roll 1. The inclination angle of this fiber material 6 is
It is preferable that the angle is 30 to 90 degrees in the circumferential direction of the cooling roll 1. In this way, by tilting the fiber material 6 in the circumferential direction of the cooling roll 1, the apparent Young's modulus can be reduced. The fiber material 6 is made of the same material as the high heat conductive fiber contained in the soft layer 3, and for example, polybenzobisoxazole (PBO) fiber, carbon fiber, nickel, chromium fiber or the like is used.

As shown in FIG. 3, for example, the fibrous material 6 is formed by bundling a plurality of high heat conductive raw fibers having a length of about 100 mm and folding the fiber half in such a manner that the core wire 7 faces substantially in the middle in the length direction. Then, the folded side is sandwiched between metal fittings 8 to form a bundle of fiber materials 6. The bundle of the fiber material 6 is wound around the surface of the cooling roll. At this time, the fiber material 6 is inclined by 30 to 90 degrees in the circumferential direction of the cooling roll 1.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete embodiment of the cooling roll 1 according to the present invention will be described with reference to FIG. FIG. 5 is an explanation showing the evaluation of the material of the soft layer 3, the apparent Young's modulus, the thickness, the thermal conductivity, the shape of the metal strip 5, and the like for the cooling roll 1 according to Examples 1 to 5 and the conventional cooling roll. FIG. In Examples 1 to 5, as shown in FIG.
Are provided with six cooling rolls 1 each having a cooling pipe 4 disposed therein, and a steel strip (metal strip 5) having a thickness of 1 mm and a width of 1200 mm is wound around the peripheral surface of each cooling roll 1 and passed therethrough. An experiment of cooling was performed.

[Experimental conditions] Cooling roll Material: SCH22 Diameter: 1500 mm Effective width: 2200 mm Soft layer Material, apparent Young's modulus, thickness, thermal conductivity: Passing conditions shown in FIG. 5 Speed: 300 m / min and 400 m / min Tension: 1 kgf / mm Cooling start zone temperature: 650 ° C Target cooling temperature: 300 to 400 ° C Target cooling rate: 50 to 150 ° C / sec

Under the above-described experimental conditions, a steel strip (metal strip 5) was wound around each of the six cooling rolls 1 at a predetermined contact angle and cooled while passing the steel strip. In each embodiment satisfying the conditions specified in the present invention, the cooling rate was set to 150
Even when the temperature was increased to 400 m / min and the cooling speed was increased to 400 m / min, cooling was possible while securing sufficient cooling efficiency, and a highly uniform cooling with a temperature deviation in the plate width direction of ± 5% was realized. . Further, the shape of the steel strip (metal strip 5) after cooling was good, and no flaw was generated on the surface. On the other hand, when a conventional cooling roll having a surface material of Fe was subjected to an experiment under the same experimental conditions as described above, the cooling efficiency was slightly inferior to each of the examples, and the temperature deviation in the sheet width direction was reduced. Was as large as ± 30%, and good results could not be obtained.

[0018]

Since the present invention has the above-described configuration,
The following effects are obtained. According to the first aspect of the present invention, the cooling roll is in contact with the metal strip via the soft layer having high thermal conductivity. Therefore, since the cooling roll and the metal strip are uniformly in close contact with each other, the metal strip is uniformly cooled in the width direction of the sheet, and the shape is not deteriorated and no flaw is generated. In addition, since the structure is simple, it is excellent in durability, can be used stably for a long period of time, and can reduce the manufacturing cost.

According to the second aspect of the present invention, the metal strip can be more uniformly cooled in the width direction by setting the thermal conductivity, apparent Young's modulus, and thickness of the soft layer within predetermined ranges. . That is, by setting the thermal conductivity of the soft layer to 10 W / mK, the cooling efficiency is increased, and the metal strip can be sufficiently cooled. Further, the apparent Young's modulus of the soft layer is 0.01 to 10 kg / mm ^2.
By setting the range, the flexibility of the soft layer can be maintained and the cooling ability can be kept high, and the shape of the metal strip is not deteriorated and the surface of the metal strip is not flawed.

According to the third aspect of the present invention, the soft layer comprises:
It is constituted by including a high thermal conductive fiber in soft rubber. Therefore, the heat conductivity between the metal strip and the cooling roll is high, and the cooling in the width direction of the metal strip can be made more uniform.

According to the fourth aspect of the present invention, a fibrous material made of high heat conductive fiber is disposed on the surface of the cooling roll. Therefore, the heat conductivity between the metal strip and the cooling roll is further enhanced, and the cooling in the width direction of the metal strip is uniform.

According to the fifth aspect of the present invention, the fiber material is disposed so as to be inclined in the circumferential direction of the cooling roll. Therefore, the apparent Young's modulus of the fiber material is reduced, and the flexibility of the soft layer is not impaired.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a cooling roll according to the present invention.

FIG. 2 is a sectional view of a fiber material in a circumferential direction.

FIG. 3 is an axial sectional view of a fiber material.

FIG. 4 is an explanatory view showing an example of arrangement of a cooling roll according to the present invention.

FIG. 5 is an explanatory diagram showing evaluation of a material of a soft layer, an apparent Young's modulus, a thickness, a thermal conductivity, a shape of a metal strip, and the like in a specific example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooling roll 2 Roll main body 3 Soft layer 4 Cooling pipe 5 Metal strip 6 Fiber material 7 Core wire 8 Hardware

Claims (5)

[Claims] 1. A cooling roll for a metal strip having a cooling medium flow passage therein, wherein a cooling layer having high thermal conductivity is provided on an outer peripheral surface of the cooling roll. 2. The soft layer has a thermal conductivity of 10 W / mK.
As described above, the apparent Young's modulus is 0.01 to 10 kg / m.
^2. The cooling roll for metal strips according to claim 1, wherein m ² and thickness are 10 to 1000 times the apparent Young's modulus. 3. The cooling roll for a metal strip according to claim 1, wherein the soft layer is formed by including a high thermal conductive fiber in a soft rubber. 4. The cooling roll for a metal strip according to claim 1, wherein a fiber material made of a high heat conductive fiber is disposed as the soft layer on the outer peripheral surface of the cooling roll. 5. The cooling roll for a metal strip according to claim 4, wherein the fiber material is disposed to be inclined in a circumferential direction of the cooling roll.