JPH062911B2 - Steel strip support roll - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention is related to AP (Continuous Annealing and Pickling).
The present invention relates to a steel strip supporting roll such as a hearth roll and a bottom roll incorporated in a vertical furnace of a continuous annealing furnace such as a furnace and a BA (Bright Annealing) furnace.

<Prior Art> As a steel strip supporting roll conventionally incorporated in a continuous annealing furnace, for example, there is a hearth roll having a structure shown in FIG.
This roll can be used for example when the strip is heated
As shown in FIG. 6A, the furnace temperature T _F is made higher than the temperature T _{S of the} strip 3 by some heating device (not shown) to heat the strip. The roll 1 is rotating in the continuous annealing furnace 2 as the strip 3 moves, and a portion 11 where the strip 3 is in contact with the roll and a portion 12 where the strip 3 is not in contact at all exist in the axial direction of the roll. .

In FIG. 2 (a), the part partitioned by the broken line 1A shows the roll shape at the temperature during roll processing, and in the figure, the roll shape is a straight roll (cylindrical roll). . And the furnace temperature T _F is strip 3
When the temperature is higher than the temperature T _{S of} , the entire circumference of the roll is heated to that temperature in the portion 12 not in contact with the strip.
In addition, the roll in the portion 11 in contact with the strip is heated over substantially the half circumference of the roll, and is cooled by the strip in the portion in contact with the strip.

As a result, the temperature of the roll portion where the strip is in contact is lower than that of the portion 12 where the strip is not in contact, and the roll shape is from the straight roll shape at the beginning of processing to the shape 1A having a recess in the central portion. Thermal deformation (so-called thermal crown).

In this state (roll with a concave central part), there will be problems on the strip passing plate as will be described later, so during roll processing, the roll is provided with an initial crown (solid line) as shown in Fig. 2 (b) 1B beforehand. If so, the high shape 1BB at the center of the roll can be maintained even during thermal deformation.

<Problems to be solved by the invention> However, the relationship between the roll shape and the stress in the strip during thermal deformation of the roll with the initial crown shown in FIG. It becomes like the figure. That is, as shown in FIG. 3 (a), the thermal deformation of the roll when the initial crown is too large is large in the central portion even after the thermal deformation. Therefore, when the strip 3 is wound around the roll 1 in such a state, a tensile stress 30 is generated in the strip contacting the roll 1 and a compressive stress as a reaction force is generated in the strip immediately before contacting the roll 1.
31 occurs. When the strip 3 buckles due to this compressive stress 31, it becomes a protrusion as shown by 34, and this is squeezed on the surface of the roll 1 to form "wrinkles" 32, so-called heat buckle, which results in defective products. turn into.

Figure 3 (b) shows that if the initial crown is too small,
Alternatively, in the case of a straight roll, the state of the roll during operation is shown, and the central portion of the surface of the roll 1 is dented and concave. When the strip is wound around the roll in this state, the strip moves toward the roll, either left or right side 33, a so-called meandering phenomenon occurs, and in extreme cases, the strip 3 rubs the furnace wall, which makes operation difficult. It will be broken or will break and you will have to stop the operation.

The present invention is made to eliminate the above-mentioned drawbacks of the conventional steel strip supporting roll incorporated in a continuous annealing furnace, and when a strip having a temperature different from the temperature inside the furnace is wound around the roll and conveyed. To heat or cool the roll,
It is an object of the present invention to provide a steel strip supporting roll that does not cause a thermal crown on the roll.

<Means for Solving Problems> The inventors of the present invention have conducted various studies to achieve the above-mentioned object, resulting in a temperature distribution in the roll, and causing the strip to be unsuccessfully conveyed due to the temperature in the continuous annealing furnace. When a metal strip with a different temperature from
It has been found that the thermal deformation caused by heating or cooling the roll and caused by the temperature distribution of the roll varies depending on the width of the metal strip. Therefore, in order to reduce the influence of the ambient temperature in the continuous furnace on the temperature of the roll wound around the roll, a radiation plate is adopted, and the shielding range of the radiation plate is adjusted according to the change of the strip width. I knew what to do.

That is, in the steel strip supporting roll according to the present invention, in the strip conveying steel strip supporting roll provided in the continuous annealing furnace, a portion where the strip does not come into contact with the roll can be adjusted in a shielding range according to the width of the strip to be threaded. It is characterized in that a radiation shielding plate is arranged.

<Operation> Since the strip 3 is configured as described above,
As shown in the figure, when the radiation shield plates 35, 35 are wound around the center of the surface of the roll 1 incorporated in the continuous annealing furnace 2 and are not in contact with the strip, the radiation shield plates 35, 35 are arranged so that they can be pulled out freely. The heated strip 3 has a temperature lower than that of the atmosphere in the furnace and further lower than that of the roll 1 which is constantly rotating in the furnace.

Therefore, the roll portion 11 that comes into contact with the strip 3 has a lower temperature than the roll portion 12 that does not come into contact with the strip 3.

Therefore, by inserting or withdrawing the shielding plate 35 corresponding to the strip width of the strip 3, the radiation shielding portion can be changed from the vicinity of the end portion of the strip to the outer roll portion 12.

<Example> Next, a typical example of the present invention will be described.

FIG. 1 shows an example in which the present invention is applied to the first roll on the inlet side of the continuous annealing furnace 2.

The dimensions of roll 1 (hearth roll) shown in Fig. 1 are: roll diameter (φ): 800 mm, roll shell thickness (t): 30 mm, [dimension and structure of radiation shield plate 35] roll width direction: 300 mm (W) Dimension: Roll radial dimension: 650mm (L), Plate thickness: 250mm (t), Material: Refractory castable, Structure: Slidably formed on a pillar 37 installed between both walls of the continuous annealing furnace wall. The operation rod 36 is fixed to the groove 37a and each plate 35 so as to be freely inserted into and removed from the furnace wall.

[Radiation shield plate 35 set position] 50 mm inside from the end of the strip 3 on the roll to the strip 3 strip center side and 250 mm from the strip edge to the furnace wall side.

[Continuous annealing furnace operating conditions] Strip size: 0.6 ^t × 1250 ^W × 350 mpm Strip temperature: 80 ° C Temperature inside the furnace: 850 ° C The roll center temperature was 170 ° C. At the position: 360 ℃ On the furnace wall side from the radiation shield 35: 730 ℃.

(Comparative Example) An experiment was conducted using a continuous annealing furnace, roll 1 and strip under the same conditions, dimensions and operating conditions as the above example except that the radiation shield plate 35 was not used. Roll center temperature: 179 ° C (strip contact part) : Temperature of 100 mm from strip edge to furnace wall: 750 ° C.

From the final state of the rolls of the example and the comparative example, in the case of the comparative example, from the roll center portion and the strip edge to the furnace wall side
Compared to the temperature difference at the position of 100 mm reaching about 600 ℃,
In the case of the example, only a difference of about 280 ° C. occurred.

Therefore, in the case of the example, the situation in which the strip almost never contacts the inner wall of the furnace did not appear during the strip transportation, but in the case of the comparative example, the strip transportation was often unstable and the transportation speed was lowered. I had to deal with the situation.

<Effects of the Invention> As is clear from the above description, when the steel strip support roll according to the present invention is used, the steel strip support roll heated by the atmosphere in the furnace comes into contact with the strip at a temperature different from the atmosphere in the furnace. Since the influence of the heat deformation of the roll that occurs as a result can be reduced and the deformation of the strip and the meandering during conveyance can be prevented, the product yield can be improved and the stability of the operation can be contributed.

[Brief description of drawings]

FIG. 1 (a) is a partial sectional side view of a steel strip supporting roll according to an embodiment of the present invention, FIG. 1 (b) is a sectional view taken along the line XX of FIG. 1 (a), and FIG. FIG. 2 (a) is a side view of a main part showing a schematic configuration of a conventional steel strip supporting roll incorporated in a continuous annealing furnace, FIG.
(b) is a partial side view of a steel strip supporting roll having a thermal deformation preventing structure, and FIGS. 3 (a) and (b) are on a steel strip supporting roll having a thermal deformation preventing structure shown in FIG. 2 (b). FIG. 4 is an explanatory diagram showing tensile tension, compressive stress, and buckling state that occur on the strip surface of FIG. In the drawing, 1 ... Roll, 2 ... Continuous annealing furnace, 3 ... Strip, 11 ... A portion of the roll which the strip comes into contact with, 12 ... A portion of the roll surface where the strip does not come into contact, 35 ... A radiation shielding plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kuniaki Sato 1 Kawasaki-cho, Chiba-shi, Chiba Inside the Kawasaki Steel Co., Ltd. (72) Inventor Norio Noda 1 Kawasaki-cho, Chiba-shi Chiba Steel In-house

Claims (1)

[Claims] 1. A strip shielding steel strip supporting roll provided in a continuous annealing furnace, wherein a radiation shielding plate is arranged so that a portion where the strip does not come into contact with the roll can be adjusted in shielding range according to the width of the strip to be stripped. Steel strip support rolls.