JP2017030037A - Conditioning rolling method of steel plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conditioning rolling method of a steel plate capable of preventing the formation of a push flaw on a roll by foreign matter stuck on a steel plate when replacing the roll.SOLUTION: In a conditioning rolling method of a steel plate for drafting the carried steel plate by using a freely replaceable roll by attaching-detaching in the axial direction, the conditioning rolling method of the steel plate resumes draft to the steel plate while releasing carrying stopping of the steel plate after sending out the steel plate in the carrying direction, by sending out the carrying-stopped steel plate in the carrying direction, while releasing the draft to the steel plate, after replacing the roll, by replacing the roll, after releasing the draft to the steel plate, while stopping carrying of the steel plate.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a temper rolling method for steel sheets.

  The temper rolling is performed by subjecting the steel sheet to light reduction of, for example, a reduction rate of about several percent or less with a temper rolling mill. By applying this temper rolling, the steel sheet is uniformly stretched, the shape thereof is corrected, a predetermined flatness is obtained, mechanical properties such as yield point elongation, tensile strength, elongation, and surface roughness of the steel sheet are obtained. Properties such as degree are also improved (see, for example, Patent Document 1).

JP 2008-173684 A

In a temper rolling mill, for example, at the timing when a welded portion of a steel sheet is conveyed, a roll such as a work roll may be exchanged (an exchange from an old roll to a new roll).
As an example, the roll exchange temporarily stops temper rolling by releasing the reduction of the steel sheet while stopping the conveyance of the steel sheet by a looper or the like. Next, after the old roll is pulled out in the axial direction and removed from the conveying path of the steel sheet, the new roll is inserted. Then, temper rolling is resumed by resuming the rolling while releasing the conveyance stop of the steel sheet.
By the way, when pulling out the old roll or inserting the new roll, foreign matter such as wear powder or grease may fall and adhere to the steel plate that is not being transported. When rolling a steel sheet to which foreign matter has adhered, the foreign matter may form a pressing ridge (dent ridge) on the work roll. In the portion where the pressing bar is formed, the rolling of the steel sheet becomes insufficient, and convex wrinkles are formed on the surface of the steel sheet, which may be a problem.

  Then, an object of this invention is to provide the temper rolling method of the steel plate which can prevent that a pressing iron is formed in a roll by the foreign material adhering on the steel plate at the time of roll replacement | exchange.

As a result of intensive studies, the present inventors have found that the above object is achieved by the following configuration. That is, the present invention provides the following [1] to [4].
[1] A temper rolling method for a steel plate that uses a roll that can be exchanged by loading and unloading in the axial direction, and temper rolling the steel plate, while rolling the steel plate and stopping the steel plate After the roll is exchanged, after the roll is exchanged, the steel plate that has been transported is stopped in the transport direction while releasing the reduction on the steel plate, and the steel plate is fed in the transport direction. A temper rolling method for a steel sheet, wherein the rolling stop of the steel sheet is resumed while releasing the conveyance stop of the steel sheet.
[2] The temper rolling method for a steel sheet according to [1], wherein the distance for feeding the steel sheet in the transport direction is a distance of 190% or more of the diameter of the roll.
[3] The temper rolling method for a steel sheet according to [2], wherein the distance for feeding the steel sheet in the conveying direction is a distance of 500% or less of the diameter of the roll.
[4] When the steel plate is sent out in the transport direction, the speed difference between the transport speed of the steel plate and the rotational speed of the roll is determined when resuming the reduction of the steel plate while releasing the transport stop of the steel plate. The steel sheet temper rolling method according to any one of [1] to [3], wherein the steel sheet is 10 mpm or less.

  ADVANTAGE OF THE INVENTION According to this invention, the temper rolling method of the steel plate which can prevent that a pressing iron is formed in a roll by the foreign material adhering on the steel plate at the time of roll replacement | exchange can be provided.

FIG. 1 is a schematic configuration diagram illustrating an example of a continuous annealing line. FIG. 2A is a schematic diagram showing a state where the steel sheet is not being crushed by the temper rolling mill, and FIG. 2B is a schematic diagram showing a state where the steel sheet is being crushed by the temper rolling mill. is there. FIG. 3 is a side view schematically showing an example of the configuration of the work roll. FIG. 3 (a) shows a state where the rail and the wheel are separated from each other, and FIG. 3 (b) shows that the rail and the wheel are separated. The contact state is shown. 4 (a) is a plan view of FIG. 3 (a), and FIG. 4 (b) is a front view of FIG. 3 (a). FIG. 5A is a schematic diagram illustrating a state in which foreign matter adheres to the steel plate that is not being transported, and FIG. 5B illustrates a state in which pressing iron is formed on the work roll by the foreign matter that has adhered to the steel plate. FIG. 5C is a schematic diagram showing a state in which convex wrinkles are formed on the steel sheet by rolling with a work roll on which pressed wrinkles are formed. 6A is a schematic diagram illustrating a state in which foreign matter adheres to the steel plate that is not transported, and FIG. 6B is a schematic diagram illustrating a state in which the steel plate to which foreign matter has adhered is delivered. (C) is a schematic diagram which shows the state which resumed temper rolling after sending out the steel plate which the foreign material adhered.

  The temper rolling method of the present invention is a temper rolling method for a steel sheet, which uses a roll that can be exchanged by loading and unloading in the axial direction to reduce the conveyed steel sheet, and stops the conveyance of the steel sheet. Meanwhile, after releasing the reduction on the steel plate, the roll is exchanged, and after the roll change, the steel plate on which the conveyance is stopped is sent out in the conveyance direction while the reduction on the steel plate is released, and the steel plate is removed. It is a temper rolling method for a steel sheet in which after the sheet is fed in the conveying direction, the rolling of the steel sheet is resumed while releasing the conveyance stop of the steel sheet.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. The following embodiment is an application example to a continuous annealing line for continuously annealing a steel sheet (cold rolled steel sheet) after cold rolling. However, the present invention is not limited to the following embodiments.

  FIG. 1 is a schematic configuration diagram illustrating an example of a continuous annealing line. In FIG. 1, the direction (conveying direction) in which the steel sheet S is conveyed is indicated by a white arrow. The continuous annealing line shown in FIG. 1 cleans a steel plate S, a payoff reel 2 that pays out a coil around which the steel plate S after cold rolling is wound, a welding machine 3 that welds and joins the steel plate S along the conveying direction. Cleaning equipment 4 for annealing, annealing furnace 1 for annealing steel sheet S, temper rolling mill 7 to be described later, inspection chamber 9 for inspecting steel sheet S, shear 10 for cutting steel sheet S, and tension reel 11 for winding steel sheet S Have. A looper 5 and a looper 6 are arranged on the entry side and the exit side of the annealing furnace 1, respectively, and a looper 8 is also arranged on the entry side of the inspection chamber 9.

FIG. 2A is a schematic diagram showing a state where the steel sheet is not being crushed by the temper rolling mill, and FIG. 2B is a schematic diagram showing a state where the steel sheet is being crushed by the temper rolling mill. is there.
As shown in FIG. 2A and FIG. 2B, the temper rolling mill 7 is a work roll 12 that is a pair of rolls that are rotatably disposed at least at a position sandwiching the conveyance path of the steel sheet S. (12a, 12b).
More specifically, the temper rolling mill 7 includes a pair of work rolls 12, a backup roll 14 (14 a, 14 b) that is a pair of rolls that support the work roll 12, and between the work roll 12 and the backup roll 14. It is a 6-roll mill comprised with a total of 6 with the intermediate | middle roll 13 (13a, 13b) which is a pair of roll arrange | positioned. However, the type of the temper rolling mill 7 is not limited to a six-fold rolling mill, and may be a total of four quadruple rolling mills excluding the intermediate roll 13 or a rolling mill with a large number of rolls.

  In the present embodiment, the work roll 12a and the work roll 12b have the same shape, and the same applies to the intermediate roll 13 and the backup roll 14.

In the temper rolling mill 7, the backup roll 14 is disposed so as to be movable up and down by a mechanism or the like (not shown). As shown in FIG. 2A, in the state where the backup roll 14a is raised and / or the backup roll 14b is lowered, the reduction of the steel sheet S is released.
On the other hand, as shown in FIG. 2B, when the backup roll 14a is lowered and / or the backup roll 14b is raised, each roll is pressed and the steel sheet S is pressed down. And the temper rolling with respect to the steel plate S is performed by conveying the steel plate S in this state.

  In the temper rolling mill 7, a tempered liquid injection nozzle 15 is disposed on the entry side of the work roll 12 and the like. The refining liquid injection nozzle 15 injects a refining liquid (mineral oil frequently used for the purpose of lubrication, cleaning, etc.) mainly into the biting portion of the steel sheet S and the work roll 12 and is used on the outlet side. The material liquid is air-wiped. In this way, wear powder and the like generated during rolling are removed.

FIG. 3 is a side view schematically showing an example of the configuration of the work roll. FIG. 3 (a) shows a state where the rail and the wheel are separated from each other, and FIG. 3 (b) shows that the rail and the wheel are separated. The contact state is shown. 4 (a) is a plan view of FIG. 3 (a), and FIG. 4 (b) is a front view of FIG. 3 (a).
As shown in FIGS. 3A to 4B, a box-shaped roll chock 16 is mounted on both ends of the work roll 12a. Since the shaft of the work roll 12a and the roll chock 16 are mounted via bearings, the roll chock 16 can be freely rotated with respect to the work roll 12a.
The work roll 12a has a configuration in which rolls can be exchanged. Although the method of exchanging rolls is not particularly limited, FIGS. 3A to 4B show a method of using a rail as an example of a structure for exchanging.
A pair of wheels 17 are rotatably attached to each roll chock 16. The rotation axis (not shown) of the wheel 17 is a direction orthogonal to the axis of the work roll 12a.
The wheel 17 is disposed above the pair of rails 18. The pair of rails 18 are arranged so as to sandwich the work roll 12a along the longitudinal direction of the work roll 12a.
The rail 18 is disposed so as to be movable in a direction in which the rail 18 is in contact with or separated from the steel sheet S (the vertical direction in FIG. 3A). For this reason, as the rail 18 moves up and down, the wheel 17 and the rail 18 can be brought into contact with and separated from each other.
Then, when the wheel 17 and the rail 18 are in contact with each other, the wheel 17 travels on the rail 18, so that the work roll 12 a is loaded and unloaded (withdrawn or loaded) along with the roll chock 16 in the axial direction. )

  3 (a) to 4 (b), the work roll 12a has been described as a representative. However, the other work roll 12b, the intermediate roll 13 (13a, 13b), and the backup roll 14 (14a, 14b) are illustrated. ) Also has roll chock attached to both ends of each roll. Moreover, it has a configuration in which rolls can be exchanged. The method of exchanging the roll is not particularly limited, and as described above, a method of using a rail by attaching a wheel to a roll chock can be used, or it can be lifted by a crane or the like. Also, in the method using rails, if the rails can be moved freely, the rails can be shared for exchanging multiple rolls, and the rails can be installed when necessary, and one side can be installed without attaching wheels to the roll chock. It can also be pulled out with a jig.

  In such a configuration, in the continuous annealing line shown in FIG. 1, the steel sheet S is transported and continuous annealing is performed. Specifically, first, the steel plate S is discharged from the coiled steel plate installed on the payoff reel 2, and the rear end portion of the preceding steel plate S and the front end portion of the subsequent steel plate S are connected to the welding machine 3. Welded with. The welded steel sheet S is cleaned in the cleaning facility 4 and then annealed in the annealing furnace 1. The annealed steel sheet S is temper-rolled by the temper rolling mill 7, then inspected in the inspection chamber 9, cut by the shear 10, and wound on the tension reel 11 in a coil shape.

During such continuous annealing, in the temper rolling mill 7, for example, when the roll of the work roll 12 or the like is exchanged (exchanging from the old roll to the new roll) at the timing when the welded portion of the steel sheet S has been conveyed, There is.
As an example of roll exchange, first, the backup roll 14 is stopped while the conveyance of the steel sheet S in the temper rolling mill 7 is stopped (apparently) by the looper 6 and the looper 8 positioned before and after the temper rolling mill 7. To release the reduction of the steel sheet S. Thus, temper rolling is temporarily stopped. Next, the wheel (wheel 17 or the like) and the rail (rail 18 or the like) are brought into contact with each other and the wheel is caused to travel along the rail, whereby the old roll is pulled out in the axial direction and removed from the conveying path of the steel sheet S. And about a new roll, it mounts in the conveyance path | route of the steel plate S by putting a wheel on a rail and makes it run, and then makes a rail separate from a wheel. After that, while stopping the conveyance stop of the steel sheet S, the backup roll 14 is brought closer to resume the reduction of the steel sheet S. Thus, the steel sheet S is lightly reduced by the work roll 12 while being conveyed and temper-rolled.

  By the way, in such a roll exchange, problems as described below based on FIGS. 5A to 5C may occur.

FIG. 5A is a schematic diagram illustrating a state in which foreign matter adheres to the steel plate that is not being transported, and FIG. 5B illustrates a state in which pressing iron is formed on the work roll by the foreign matter that has adhered to the steel plate. FIG. 5C is a schematic diagram showing a state in which convex wrinkles are formed on the steel sheet by rolling with a work roll on which pressed wrinkles are formed.
As described above, when the roll is exchanged, the roll is released while stopping the conveyance of the steel sheet S, and then the old roll is pulled out or the new roll is inserted. At this time, as shown in FIG. 5A, foreign matter 21 such as wear powder accumulated on the rail or grease used in a roll chock or the like falls (drops) on the surface of the steel sheet S and adheres. There is a case.
As shown in FIG. 5B, when the temper rolling is resumed for the steel sheet S to which the foreign material 21 is adhered, the foreign material 21 may form a push rod 19 that is a dent in the work roll 12a.
And as shown in FIG.5 (c), in the part in which the pressing bar 19 in the work roll 12a was formed, rolling of the steel plate S becomes inadequate and the convex scissors 20 are formed on the surface of the steel plate S. Since such convex ridges 20 are formed on the surface of the steel sheet S with the diameter pitch of the work rolls 12a, the convex ridges 20 are confirmed in the inspection room 9 in distinction from other ridges.

Therefore, in the present embodiment, the above problem is solved as described below with reference to FIGS. 6 (a) to 6 (c).
6A is a schematic diagram illustrating a state in which foreign matter adheres to the steel plate that is not transported, and FIG. 6B is a schematic diagram illustrating a state in which the steel plate to which foreign matter has adhered is delivered. (C) is a schematic diagram which shows the state which resumed temper rolling after sending out the steel plate which the foreign material adhered.
Also in this embodiment, at the time of roll exchange, after releasing the reduction while stopping the conveyance of the steel sheet S, the old roll is pulled out and then the new roll is inserted. For this reason, as shown in FIG. 6A, foreign matter 21 such as wear powder may adhere to the surface of the steel sheet S.

  However, in this embodiment, before restarting the temper rolling after that, first, as shown in FIG. 6 (b), by the looper 6 and the looper 8 and the like positioned before and after the temper rolling mill 7, The steel plate S that is being transported is sent out in the transport direction by a predetermined distance.

  In FIG. 6B, the backup roll 14 is separated and the rail 18 and the wheel 17 are in contact with each other (see FIG. 3B), and the work roll 12a and the steel plate S are in contact with each other. When the steel sheet S is fed out, the foreign matter 21 on the surface of the steel sheet S does not contact the work roll 12a.

  After the steel plate S being stopped is sent out, the backup roll 14 is approached while releasing the transport stop of the steel plate S, and the steel plate S is brought down again as shown in FIG. Thus, the steel sheet S is lightly reduced by the work roll 12 while being conveyed, and the temper rolling is resumed.

In addition, as distance which sends out the steel plate S to a conveyance direction, when refining rolling is restarted, if it is a distance which does not roll the foreign material 21, it will not specifically limit, For example, it is a distance of 190% or more of the diameter of a roll Is preferred.
Here, the “roll” refers to a roll to be exchanged in the present embodiment (the same applies hereinafter). When exchanging a plurality of rolls, the roll with the largest diameter among the rolls to be exchanged is pointed out. Moreover, when the diameter differs before and after roll replacement, the roll having the larger diameter is indicated (hereinafter the same).
Further, the upper limit of this distance is not particularly limited, but if it is too long, the yield may be unnecessarily deteriorated, so a distance of 500% or less of the diameter of the roll is preferable.

  Further, after the steel sheet S is sent out in the transport direction, when the reduction of the steel sheet S is resumed while releasing the transport stop of the steel sheet S, there is a speed difference between the transport speed of the steel sheet S and the rotational speed of the roll. However, from the viewpoint of the influence on the elongation and shape of the steel sheet S, it is preferable that the speed difference is small, specifically, 10 mpm or less is preferable, 2 mpm or less is more preferable, and there is no speed difference. More preferably (the speed difference is set to 0 mpm).

As described above, even if the foreign matter 21 adheres to the surface of the steel sheet S at the time of roll replacement, according to the present embodiment, the region where the foreign matter 21 adheres in the steel sheet S is sent to the downstream side. In order to avoid the region and resume the temper rolling, it is possible to prevent the pressing bar 19 from being formed on the work roll 12a or the like by rolling the steel sheet S to which the foreign matter 21 is adhered.
For this reason, since the roll replacement cost or roll processing cost caused by the formation of the pressing bar 19 can be reduced, a reduction in cost can be realized.

  In addition, since the area | region which the foreign material 21 adhered in the steel plate S is sent out as mentioned above, it becomes a part which is not rolled with the temper rolling mill 7, but originally, since it is an unused part cut | disconnected with the shear 10, It doesn't matter.

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.

  The steel sheet S was subjected to continuous annealing in the continuous annealing line described based on FIGS. Then, the rolls such as the work roll 12 were exchanged as appropriate (exchanging from the old roll to the new roll). The work roll 12 should be usable without being replaced while the surface roughness falls within a predetermined range. However, before the application of the present invention, the pressing roll 19 is pressed on the roll at the time of roll replacement at 10% of the roll replacement frequency. It was formed and it was necessary to replace the roll again. On the other hand, after the application of the present invention, the frequency of early roll exchange by pressing rods was improved to 0%.

1: Annealing furnace 2: Payoff reel 3: Welding machine 4: Cleaning equipment 5: Looper 6: Looper 7: Temper rolling mill 8: Looper 9: Inspection room 10: Shear 11: Tension reel 12 (12a, 12b): Workpiece Roll
13 (13a, 13b): Intermediate roll (roll)
14 (14a, 14b): Backup roll (roll)
15: Conditioning liquid injection nozzle 16: Roll chock 17: Wheel 18: Rail 19: Push rod 20: Convex rod 21: Foreign material S: Steel plate

Claims (4)

A temper rolling method for a steel sheet, using a roll that can be exchanged by loading and unloading in the axial direction, and rolling down the steel sheet to be conveyed,
After releasing the reduction on the steel plate while stopping the conveyance of the steel plate, the roll is exchanged,
After exchanging the rolls, the steel plate that has been transported is sent out in the transport direction while releasing the reduction on the steel plate,
A temper rolling method for a steel sheet, wherein after the steel sheet is sent out in a conveying direction, the reduction of the steel sheet is resumed while releasing the conveyance stop of the steel sheet.   The temper rolling method for a steel sheet according to claim 1, wherein a distance for feeding the steel sheet in a conveying direction is a distance of 190% or more of a diameter of the roll.   The temper rolling method for a steel sheet according to claim 2, wherein a distance for feeding the steel sheet in a conveying direction is a distance of 500% or less of a diameter of the roll.   When the steel plate is sent out in the conveyance direction and then the conveyance stop of the steel plate is released and the reduction of the steel plate is resumed, the speed difference between the conveyance speed of the steel plate and the rotation speed of the roll is 10 mpm or less. The temper rolling method for a steel sheet according to any one of claims 1 to 3.

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