JP2014046352A - Manufacturing facility of hot rolled steel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a position adjustment mechanism of a crosshead for making work rolls be roll-crossed from being exposed to cooling water.SOLUTION: A manufacturing facility of a hot rolled steel sheet includes a cooling device 3 for cooling a rolled material 1 immediately after rolling. A rolling mill 2 has: work-rolls 10a, 10b; work-roll chocks 11a, 11b for supporting the work-rolls 10a, 10b; backup rolls 20a, 20b; backup roll chocks 21a, 21b for supporting the backup rolls 20a, 20b; and a roll cross mechanism for moving the work-roll chocks 11a, 11b and the backup roll chocks 21a, 21b in a horizontal plane. The roll cross mechanism has a position adjustment mechanism provided at the inlet side in a sheet passing direction of the rolling mill and a pressing mechanism provided at the outlet side in the sheet passing direction of the rolling mill. The work-rolls 10a, 10b are installed more on the inlet side in the sheet passing direction from the backup rolls 20a, 20b.

Description

  The present invention relates to a production facility for hot-rolled steel sheets provided with a cooling device in the immediate vicinity of the exit side in the sheet feeding direction in a roll cloth rolling mill.

  In rolling hot-rolled steel sheets, rolling conditions such as rolling force and rolling speed by a rolling mill, cooling conditions such as cooling power and cooling speed by a cooling device, etc. affect the characteristics of the hot-rolled steel sheets to be produced. That is, the characteristics of the hot-rolled steel sheet that is the material to be rolled can be changed by changing the setting conditions of the rolling mill, the cooling device, and the like.

  For example, immediately after rolling a hot-rolled steel sheet under a high pressure of 20% or more in each stand from the latter stage to the final stage of a finish rolling mill of a hot rolling facility, when the hot-rolled steel sheet is rapidly cooled by a cooling device, It is known that a high-strength steel sheet with a small amount of addition and fine crystal grains can be produced (Non-Patent Document 1). As a rolling mill capable of rapid cooling immediately after high-pressure rolling, there is a rolling mill in which a miniaturized cooling device is installed in the immediate vicinity of the sheet feeding direction exit side of the work roll of the rolling mill (Patent Document 1).

  In the production of the high-strength steel sheet, since the rolling is performed under a high pressure of 20% or more in each stand from the latter stage to the last stage of the finish rolling mill of the hot rolling equipment, the elastic deformation of the work roll is large, Deformation is also added and deformed complicatedly. Therefore, the flatness of the material to be rolled is lowered. A material to be rolled having a low flatness is not only cooled uniformly, but also breaks and the operation tends to become unstable.

  As a technique for improving the flatness of a material to be rolled in high-pressure rolling, for example, there is a roll cloth mechanism that tilts a roll in accordance with elastic deformation of a work roll. The roll cross mechanism adjusts the gap between the upper and lower work rolls by crossing the axes of the upper and lower work rolls. By crossing the axes of the upper and lower work rolls, the gap between the upper and lower work rolls is small near the center in the width direction of the work roll, and the gap between the upper and lower work rolls is increased near both ends in the width direction of the work roll. . The flatness is improved by canceling the elastic deformation of the work roll by this mechanism.

  The roll cross mechanism presses a work roll chock and a backup roll chock that rotatably support the work roll and the backup roll, respectively, against a cross head that can be adjusted in the sheet passing direction provided on the exit side in the sheet passing direction in the rolling mill. is there. In the position adjustment of the crosshead, positioning accuracy and holding rigidity are required, so a mechanical position adjustment mechanism using a gear or the like is employed. As a technique related to a rolling mill having a roll cloth mechanism, for example, there is Patent Document 2.

JP 2012-66266 A JP 2003-12211 A

Iron and Steel Society Exhibited Literature 125th Rolling Theoretical Subcommittee "Development of Super Fine Grain Hot Rolled Steel Sheet Technology SSMR Method and Its Material Properties"

  However, in a rolling mill capable of rapid cooling immediately after high-pressure rolling in order to produce the high-strength steel sheet described above, the cooling water is filled on the exit side in the sheet passing direction in the rolling mill, so that the position adjustment of the crosshead is performed. The mechanical position adjusting mechanism that performs the above is exposed to a large amount of cooling water.

  Therefore, it is conceivable to provide a mechanical position adjustment mechanism on the entry side in the sheet feeding direction in the rolling mill. However, when the material to be rolled exits the preceding rolling mill, a force is generated in the rolling mill on the exit side in the sheet passing direction. Therefore, it is necessary to prevent the rolling roll from moving by pressing with a large force. . In order to suppress the above-mentioned force with a hydraulic cylinder or the like instead of a mechanical position adjustment mechanism with high positioning accuracy and holding rigidity, a larger hydraulic cylinder or the like must be installed compared to the outlet side installation.

  The present invention has been made in view of the above problems, and there is provided a crosshead position adjusting mechanism for roll-crossing a work roll while minimizing an increase in size of a hydraulic cylinder or the like that is a pressing mechanism for pressing the work roll chock against the crosshead. The purpose is to prevent exposure to cooling water.

  A hot-rolled steel sheet manufacturing facility according to a first aspect of the present invention for solving the above problems includes a rolling mill for rolling the material to be rolled, and a heat provided with a cooling device for cooling the material to be rolled immediately after rolling by the rolling mill. The rolling mill has a roll cloth mechanism that moves the work roll chock in a horizontal plane, and the mechanical roll cloth mechanism is provided on the entry side in the sheet feeding direction of the rolling mill. A position adjusting mechanism that adjusts the position of the pressing portion against which the work roll chock is pressed, and a pressing mechanism that is provided on the exit side in the sheet feeding direction of the rolling mill and presses the work roll chock against the pressing portion of the position adjusting mechanism. The work roll is installed so that the axis of the work roll is located on the entry side in the sheet passing direction with respect to the axis of the backup roll.

  A hot-rolled steel sheet manufacturing facility according to a second invention that solves the above-mentioned problems is the hot-rolled steel sheet manufacturing facility according to the first invention, wherein the position adjusting mechanism has a pair of upper and lower work roll axes in a horizontal plane. When the cross angle intersecting is increased, the pressing portion of the position adjusting mechanism is operated to move to the entrance side in the plate direction.

  According to the hot-rolled steel sheet manufacturing facility according to the first aspect of the invention, since the position adjustment mechanism of the roll cloth mechanism is provided on the entrance side of the rolling plate in the sheet feeding direction, the position adjustment mechanism is exposed to cooling water and deteriorated. There is no fear of doing it. Since the flatness of the material to be rolled is improved by compensating for the elastic deformation of the work roll by the roll cloth mechanism, the instability of the operation such as sheet cutting is reduced. Furthermore, since the flatness of the material to be rolled is improved, the degree of cooling in the material to be rolled can be made uniform and uniform rapid cooling can be performed, so that the amount of alloy elements added is small and the crystal grains are refined. A high strength steel sheet having a uniform surface can be manufactured. Moreover, since the work roll is installed on the entry side in the plate direction with respect to the backup roll, the work roll is generated by the force on the exit side in the plate direction generated in the rolling mill when the material to be rolled passes through the preceding rolling mill. Does not move.

  According to the hot-rolled steel sheet manufacturing equipment according to the second aspect of the invention, by moving the pressing portion of the position adjustment mechanism to the plate direction entry side, the cross angle at which the axes of the pair of upper and lower work rolls intersect in the horizontal plane is set. Since it increases, the installation space of the cooling device installed immediately in the sheet-feeding direction exit side in a rolling mill will be expanded, and the restrictions of movable space and interference will become loose. Therefore, the cross angle of the work roll can be increased without restriction while ensuring the space on the exit side in the sheet feeding direction in the rolling mill.

It is a longitudinal cross-sectional view which shows the manufacturing equipment of the hot-rolled steel plate which concerns on Example 1. FIG. It is a longitudinal cross-sectional view which shows the manufacturing equipment of the hot-rolled steel plate which concerns on Example 1. FIG. It is the schematic which shows the cross angle in the manufacturing equipment of the hot rolled sheet steel which concerns on Example 1. FIG. It is the schematic which shows the offset amount of the work roll in the manufacturing equipment of the hot-rolled steel plate which concerns on Example 1. FIG.

  Below, the Example of the manufacturing equipment of the hot rolled sheet steel which concerns on this invention is described in detail with reference to an accompanying drawing. Needless to say, the present invention is not limited to the following examples, and various modifications can be made without departing from the spirit of the present invention.

  The configuration of the hot-rolled steel sheet manufacturing facility according to the present embodiment will be described with reference to FIGS.

  As shown in FIG. 2, the production facility for hot-rolled steel sheets according to this example rolls a strip 1 that is a material to be rolled by a rolling mill 2, and the strip plate 1 in the rolling mill 2 exits in the sheet feeding direction ( It cools with the cooling equipment 3 installed in the downstream (left side in the figure). In addition, the tension | tensile_strength is controlled by the pinch roll apparatus 4 installed in the downstream of the cooling equipment 3 so that the strip 1 after the rolling by the rolling mill 2 may not be bent by its own weight. Guide of the plate to the pinch roll device 4 of the band plate 1 is performed by a side guide 5 installed on the upstream side of the pinch roll device 4.

  The rolling mill 2 is installed at the final stage in the hot rolling facility, and a pair of upper and lower work rolls 10a and 10b for rolling the strip 1 and work roll chocks 11a and 11b for rotatably supporting the work rolls 10a and 10b, A pair of upper and lower backup rolls 20a, 20b installed opposite to the work rolls 10a, 10b, backup roll chock 21a, 21b for rotatably supporting the backup rolls 20a, 20b, work roll chock 11a, 11b and backup roll chock 21a, And a housing 30 for supporting 21b.

  The work roll chock 11a, 11b and the backup roll chock 21a, 21b in the rolling mill 2 are movable in a horizontal plane by a roll cross mechanism described later together with the work rolls 10a, 10b and the backup rolls 20a, 20b.

  The cooling facility 3 is a water-injection type cooling facility that injects cooling water to cool the strip 1, and is a pair of upper and lower first cooling units that are installed on the downstream side of the work rolls 10 a and 10 b in the rolling mill 2. It consists of devices 40a, 40b, a pair of upper and lower second cooling devices 50a, 50b, and a pair of upper and lower third cooling devices 60a, 60b.

  The first cooling devices 40a and 40b are installed in a pair of upper and lower sides with respect to the band plate 1 inside the housing 30 adjacent to the downstream side of the work rolls 10a and 10b, and the cooling water of the work rolls 10a and 10b is supplied to the band plate 1. The stripper guides 41a and 41b that come into contact with the work rolls 10a and 10b and the cooling water are sprayed onto the band plate 1 in order to prevent the water from falling onto the work rolls 10a and 10b. 1st nozzle header 42a, 42b which attached many nozzles 70, and cools the to-be-rolled material 1 in the 1st cooling zone A. As shown in FIG. The upper cooler 40a of the first cooling device and the lower cooler 40b of the first cooling device are respectively connected to the upper cooler 50a of the second cooling device and the second cooling by the first hydraulic cylinders 80a and 80b. It slides in the plate passing direction with respect to the lower cooler 50b of the apparatus, and presses the work rolls 10a and 10b to follow the stripper guides 41a and 41b, thereby adjusting the force.

  The second cooling devices 50a and 50b are installed in a pair of upper and lower sides with respect to the strip 1 adjacent to the downstream side of the first cooling devices 40a and 40b, and guide the strip 1 so that the strip 1 is correctly passed. It has 2nd nozzle headers 52a and 52b which attached many nozzles 70 which inject | pour the plate guides 51a and 51b and the cooling water into the strip 1, and cools the to-be-rolled material 1 in the 2nd cooling zone B. . The upper cooler 50a of the second cooling device and the lower cooler 50b of the second cooling device are slidable in the plate passing direction with respect to the housing 30 by the second hydraulic cylinders 90a and 90b. The first cooling devices 40a and 40b are installed in a nested structure in the second cooling devices 50a and 50b.

  The third cooling devices 60a and 60b are installed in a pair of upper and lower sides with respect to the band plate 1 outside the housing 30 adjacent to the downstream side of the second cooling devices 50a and 50b, and the band plate 1 is correctly passed. And the third nozzle headers 62a and 62b to which a large number of nozzles 70 for injecting cooling water onto the strip plate 1 are attached. Cool down. The upper cooler 60a of the third cooling device can be moved in the vertical direction perpendicular to the sheet passing direction by an elevating mechanism (not shown), and the lower cooler 60b of the third cooling device is fixed to a gantry (not shown). .

  As shown in FIG. 1, the roll cross mechanism provided in the rolling mill 2 includes position adjusting mechanisms 130a, 130b that adjust the positions of the cross heads 110a, 110b, 120a, 120b in the plate passing direction by the drive motors 100a, 100b, From the pressing mechanism (in this embodiment, pressing hydraulic cylinders 140a, 140b, 150a, 150b) that press the roll chocks 11a, 11b and the backup roll chock 21a, 21b against the corresponding cross heads 110a, 110b, 120a, 120b. Become.

  The position adjustment mechanisms 130a and 130b include drive motors 100a and 100b installed on the upper side of the housing 30 of the rolling mill 2 in the sheet feeding direction, worm gears 101a and 101b connected to the drive motors 100a and 100b, and worm gears 101a and 101b. Crossheads 110a, 110b, 120a, 120b attached to the head. When the drive motors 100a, 100b are operated to drive the worm gears 101a, 101b, the cross heads 110a, 110b, 120a, 120b move back and forth in the plate passing direction.

  On the outlet side in the sheet passing direction of the housing 30 of the rolling mill 2, pressing hydraulic cylinders 140a, 140b, 150a, 150b, which are pressing mechanisms in the roll cloth mechanism, are installed. By extending the pressing hydraulic cylinders 140a, 140b, 150a, 150b, the work roll chock 11a, 11b and the backup roll chock 21a, 21b are moved to the cross heads 110a, 110b, 120a, 120b which are pressing portions of the position adjusting mechanisms 130a, 130b. Pressed.

  That is, the positions of the work roll chock 11a, 11b and the backup roll chock 21a, 21b are determined by the positions of the cross heads 110a, 110b, 120a, 120b, and the upper work of the roll cross mechanism is determined by the positions of the work roll chock 11a, 11b and the backup roll chock 21a, 21b. An angle θ (cross angle θ, see FIG. 3) formed by the roll 10a and the upper backup roll 20a and the lower work roll 10b and the lower backup roll 20b in the horizontal direction is determined.

  By moving the cross heads 110a, 110b, 120a, 120b of the position adjustment mechanisms 130a, 130b from the position where the cross angle is not provided (θ = 0 °) to the entry side in the sheet passing direction, the axes of the pair of upper and lower work rolls are moved. The cross angle θ intersecting in the horizontal plane is increased. By doing in this way, work roll chock 11a, 11b and backup roll chock 21a, 21b do not move to the sheet feeding direction exit side with work roll 10a, 10b and backup roll 20a, 20b. Therefore, it is not necessary to predict the mechanical interference by the installation space and the movement of the cooling device 3 and to secure an extra space.

  Further, as shown in FIG. 4, the work rolls 10 a and 10 b are passed through the backup rolls 20 a and 20 b so as to suppress the force applied to the exit side in the sheet passing direction when the strip 1 is bitten into the rolling mill 2. Installed with offset amount d on the direction entry side. Since the force applied to the exit side in the threading direction acts in a distributed manner on the backup rolls 20a, 20b and the pressing hydraulic cylinders 140a, 140b, 150a, 150b, the pressing hydraulic cylinders 140a, 140b, 150a, 150b are enlarged. It can be suppressed (see FIG. 1).

  Next, the operation of the hot-rolled steel sheet manufacturing facility according to the present embodiment will be described with reference to FIGS.

  The drive motors 100a and 100b are operated, the worm gears 101a and 101b are driven, and the cross heads 110a, 110b, 120a and 120b are moved to predetermined positions. The work roll chock 11a, 11b and the backup roll chock 21a, 21b are pressed against the cross heads 110a, 110b, 120a, 120b moved to predetermined positions by the extending operation of the pressing hydraulic cylinders 140a, 140b, 150a, 150b.

  As shown in FIG. 3, due to the horizontal movement of the work roll chock 11a, 11b and the backup roll chock 21a, 21b, the upper work roll 10a and the upper backup roll 20a are inclined by an angle θ, and the lower work roll 10b and the lower backup roll 20b are angle θ. Just lean.

  The work rolls 10a and 10b are elastically deformed by high-pressure rolling, and the gap between the upper work roll 10a and the lower work roll 10b is increased near the center in the width direction of the strip 1. In order to compensate for this, the upper work roll 10a and the lower backup roll 20b are crossed at a cross angle θ by the roll cross mechanism so that the upper work roll 10a and the upper backup roll 20a intersect the lower work roll 20b. The gap with 10b becomes small near the center in the width direction of the strip 1. The flatness of the strip 1 rolled by the rolling mill 2 is improved by both actions.

  As shown in FIG. 2, the strip 1 with improved flatness is immediately rolled in the first cooling zone A by the work rolls 10a and 10b in the rolling mill 2 (in this embodiment, within 0.2 seconds after rolling). ) Is cooled by the first cooling devices 40a and 40b. Next, in the second cooling zone B, the strip 1 is further cooled by the second cooling devices 50a and 50b without leaving the cooling by the first cooling devices 40a and 40b. Next, in the third cooling zone C, the strip 1 is sufficiently cooled by the third cooling devices 60a and 60b.

  By forming the first cooling devices 40a and 40b with a simple structure and reducing the size, the stripper guides 41a and 41b come close to the exit side in the sheet feeding direction of the rolling mill 2 so as to contact the work rolls 10a and 10b. The 1st cooling device 40a, 40b can be arrange | positioned and the cooling of the strip 1 can be started immediately after rolling. Therefore, it is possible to manufacture a high-strength steel sheet with a small amount of alloy elements added and crystal grains refined.

  By reducing the size of the second cooling devices 50a and 50b with a simple structure, the second cooling devices 50a and 50b can be arranged between the first cooling devices 40a and 40b and the third cooling devices 60a and 60b. The strip 1 can be continuously cooled even after cooling by 40b. Therefore, the strip 1 can be sufficiently cooled together with the first cooling devices 40a and 40b. In addition, the cooling capacity as the whole cooling equipment 3 can be improved by providing the 2nd cooling device 50a, 50b with a cooling capability higher than the 1st cooling device 40a, 40b. Since the second cooling devices 50a and 50b are installed not on the work rolls 10a and 10b but on the downstream side of the first cooling devices 40a and 40b, the second cooling devices 50a and 50b are allowed to increase in size as the cooling capacity is improved.

  By providing the third cooling device 60a, 60b with a higher cooling capacity than the first cooling device 40a, 40b and the second cooling device 50a, 50b, the rolled strip 1 can be wound around a coil (not shown). Sufficient cooling can be performed. Since the third cooling devices 60a and 60b are installed not on the work rolls 10a and 10b or the first cooling devices 40a and 40b but on the downstream side of the second cooling devices 50a and 50b, the cooling capacity is improved. Further increase in size associated with is allowed.

  When the strip 1 passes through a preceding rolling mill (not shown), a force is generated in the rolling mill 2 toward the exit side in the sheet passing direction. In the production equipment for hot-rolled steel sheets of the present embodiment, as shown in FIG. 4, the work rolls 10 a, 10 b are installed on the entry side with respect to the backup rolls 20 a, 20 b. 10b does not move.

  As described above, the flatness of the strip 1 is improved by compensating for the elastic deformation of the work rolls 10a and 10b by the roll cross mechanism, and the possibility that the operation becomes unstable due to the occurrence of plate breakage or the like is reduced. Furthermore, since the cooling level in the strip 1 can be uniform and uniform rapid cooling can be performed, it is possible to manufacture a high-quality steel sheet with a small amount of alloy elements added and a fine crystal grain. it can.

  In the present invention, even in the case of cooling immediately after rolling, the mechanical structure of the roll cloth mechanism is not exposed to cooling water and is not deteriorated. Therefore, manufacturing in hot rolling for the purpose of refining crystal grains in a steel sheet It is suitable as equipment. Of course, the present invention is not limited to the rolling mill at the final stage, and the hot rolled steel sheet in which the cooling equipment 3 is installed on the exit side in the sheet passing direction of the rolling mill installed at a position other than the final stage, and the roll cloth mechanism as in this embodiment is provided. It is good also as manufacturing equipment in continuous casting rolling which can change rolling conditions during rolling.

DESCRIPTION OF SYMBOLS 1 Strip 2 Rolling machine 3 Cooling equipment 4 Pinch roll device 5 Side guide 10 Work roll 20 Backup roll 30 Housing 40 First cooling device 41 Stripper guide 42 of the first cooling device Nozzle header 50 of the first cooling device Second cooling device 51 Second cooling device passage guide 52 Second cooling device nozzle header 60 Third cooling device 61 Third cooling device passage guide 62 Third cooling device nozzle header 70 Nozzle 80 First hydraulic cylinder 90 Second hydraulic cylinder 100 Drive motor 101 Worm gear 110 Cross head 120 corresponding to work roll chock Cross head 130 corresponding to backup roll chock Position adjusting mechanism 140 Hydraulic cylinder for pressing 150 corresponding to work roll chock Backup roll chock Corresponding pushing hydraulic cylinder

Claims (2)

A rolling mill for rolling a material to be rolled, and a manufacturing facility for a hot-rolled steel sheet comprising a cooling device for cooling the material to be rolled immediately after rolling by the rolling mill,
The rolling mill includes a pair of upper and lower work rolls for rolling the material to be rolled, a pair of upper and lower work roll chock that rotatably supports the work roll, and a pair of upper and lower backup rolls opposed to the pair of upper and lower work rolls. A pair of upper and lower backup roll chock that rotatably supports the backup roll, and the work roll chock and the backup roll chock in the horizontal plane so that the axes of the upper and lower pair of work roll and the upper and lower pair of backup rolls intersect in the horizontal plane. A roll cross mechanism to be moved,
The roll cloth mechanism is provided on the entry side of the rolling mill in the sheet feeding direction, a position adjusting mechanism for adjusting the position of the pressing portion to which the work roll chock and the backup roll chock are pressed, and the sheet rolling direction exit side of the rolling mill A pressing mechanism that presses the work roll chock and the backup roll chock against the pressing portion of the position adjustment mechanism,
The said work roll is installed so that the axial center of the said work roll may be located in the sheet-passing direction entrance side rather than the axial center of the said backup roll. The manufacturing equipment of the hot-rolled steel plate characterized by the above-mentioned.   The position adjusting mechanism operates to move the pressing portion of the position adjusting mechanism to the inboard direction when the cross angle at which the axes of the pair of upper and lower work rolls intersect in a horizontal plane is increased. The manufacturing equipment for hot-rolled steel sheets according to claim 1.

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