JP6431657B2 - Width reduction press method and width reduction press apparatus - Google Patents

Description

  The present invention relates to a technique for significantly reducing camber of a rolled plate in a hot rolling process of a metal plate including a slab width reduction pressing process.

  There are two types of hot slab width reduction processes, a method using a roll rolling mill and a method using a width reduction press device equipped with a width reduction press tool. There is little width return by horizontal rolling. That is, since the width reduction efficiency is excellent, and the crop at the leading end is small and the yield is good, the width reduction press apparatus is often employed in recent years. The configuration of a hot rolling line having a width reduction press device is generally as follows. The width reduction press is installed on the outlet side of the heating furnace, and the hot slab after extraction from the heating furnace is first reduced in width by the width reduction press, and then the sheet thickness is reduced by rolling with a roughing mill having a horizontal roll. Then, it becomes a rough bar and is rolled to the product sheet thickness by a finish rolling mill. The following description of the present specification also describes such a hot rolling line.

  Now, when the width reduction press is performed with a width reduction press device, the bending of the rolled sheet after rough rolling and finish rolling, that is, the camber becomes large, which may cause a problem. . This is considered to be mainly due to the difference in deformation resistance due to temperature deviation between the hot rolling line work side and the drive side of the slab.

  For example, Patent Document 1 discloses a width reduction operation in which the temperature reduction of the slab is detected and the width reduction operation is performed by intentionally making a difference in the reduction phase of the width reduction press tool on the working side and the drive side of the width reduction press device. A pressing method is disclosed.

  Patent Document 2 discloses a width reduction press method in which a camber is detected from the load of a scissors roll arranged on the exit side of the width reduction press device, and the camber is controlled by inclining the press tool within the plate surface.

  Patent Document 3 discloses a method of detecting a temperature deviation of a slab, and spraying a refrigerant before a width reduction pressing operation to eliminate the temperature deviation.

  Patent Document 4 discloses a method of performing a width reduction press while constraining the end surface of a slab with a side guide installed on at least one of an entry side and an exit side of a width reduction press device.

JP 2001-113338 A JP-A-6-277717 JP-A-6-304601 Japanese Patent Laid-Open No. 10-94801

  Although the methods disclosed in Patent Documents 1 and 2 are effective in reducing the width reduction press device outlet camber, the camber generated in the process of sheet thickness reduction in the subsequent rough rolling cannot be suppressed. This is because when the slab has a temperature deviation, the plate thickness increase phenomenon caused by the width reduction press, that is, the dogbone shape has a deviation on the working side and the driving side. This is because a solution to this problem is not disclosed in Patent Documents 1 and 2.

  On the other hand, the elimination of the temperature deviation due to the spraying of the refrigerant in Patent Document 3 eliminates the root cause of the occurrence of camber and is effective in principle, but in reality it has a large heat capacity such as a slab. It is difficult to eliminate temperature deviations in a short time without impairing rolling efficiency, and it is even more difficult to implement cooling that accurately compensates for the temperature distribution in the width direction. It is difficult to put it into practical use.

The slab restraint by the side guide of Patent Document 4 is to reduce the width in a state where the slab is sandwiched between the side guides in order to exert the effect, but in this case, the friction acting between the slab and the side guides Due to the force, the work of sending the slab in the direction of travel becomes unstable, and eventually a clearance must be provided between the slab and the side guide, so that a sufficient effect cannot be expected. In addition, since it is difficult to install the side guide in the immediate vicinity of the press tool, it is a great disadvantage that the camber does not have an effect on the leading end of the slab where the problem arises.
Therefore, the present invention discloses a width reduction press method and a width reduction press apparatus that eliminates camber associated with the width reduction press work that could not be solved by the conventional technology as described above.

  In order to clarify the generation mechanism of camber accompanying the width reduction press operation, the present inventors have determined the temperature distribution of the slab on the inlet side of the width reduction press in the actual hot strip mill, the camber on the outlet side of the width reduction press device, and the width reduction. The camber on the exit side of the rough rolling mill, that is, the horizontal roll rolling mill following the press apparatus was measured, and the generation behavior of the camber accompanying the width reduction pressing operation was observed in detail. In addition, the width reduction press apparatus of the actual hot strip mill to be measured is a type having a pair of pinch rolls on the entry side and the exit side of the width reduction press tool. In the following description, the working side and the driving side in the width direction of the slab may be simply expressed as “left and right”.

  As a result of the above measurement, it is clear that the camber on the exit side of the width reduction press is very small, but the camber on the exit side of the rough rolling machine is particularly prominent at the tip and tail ends of the rolled material. It has been found that the camber produced by the horizontal rolling of the left-right asymmetric dogbone shape is a more serious problem than the camber produced during the width reduction press which is to be suppressed in Documents 1 and 2.

  Furthermore, the temperature distribution of the slab on the width-press press entry side was such that the drive side temperature was higher than the work side temperature in all slabs. This is presumed to be the result of heat deprived from the work side of the slab near the extraction port of the heating furnace. As a result, the deformation resistance of the slab is relatively higher on the working side and smaller on the driving side, and the width reduction amount on the driving side is larger than that on the working side during width reduction pressing, and the plate thickness on the driving side is larger than that on the working side. Asymmetry of the bone shape occurs. At this time, in the width reduction pressing operation, since the width reduction pressing tool is in contact with the slab in a wide area in the longitudinal direction (slab traveling direction), most of the metal squeezed in the sheet width direction flows in the sheet thickness direction. Since it does not flow in the direction, it is considered that almost no camber is generated immediately after the width reduction press.

  By the way, when the deformation resistance on the drive side of the slab is smaller than that on the work side, the following explanation is supplemented for the mechanism in which the width reduction amount on the drive side is larger than the width reduction amount on the work side. The movement accompanying the reduction of the width reduction press tool is always symmetrical with respect to the center line of the hot rolling line. At this time, if the deformation resistance on the driving side is relatively small, the pressing load on the width side on the driving side becomes smaller than that on the work side, and the force in the width direction acting on the slab cannot be balanced as it is. The slab moves to the drive side until the load is balanced between the drive side and the work side. As a result, the width reduction amount on the drive side is large and the width reduction amount on the work side is small.

FIG. 9 and FIG. 10 are views showing a state when the vicinity of the tip of the slab 2 is being pressed under a width, and FIG. 9 shows a virtual state in which the balance of forces acting on the slab 2 is ignored. As shown in FIG. 9A, since the slab exists at the center of the hot rolling line, the width reduction amount becomes equal to the left and right, and the exit cross section of the slab shown in FIG.
However, in this state, the force acting on the slab from the pressing tool under the width reduction causes the work-side force 15a to be greater than the driving-side force 15b due to the difference in deformation resistance, and the force acting on the slab cannot be balanced. Therefore, the slab 2 is slightly rotated by the unbalanced force in the direction in which the width reduction amount on the driving side is increased with the position of the entry side pinch roll 3 restrained in the width direction as a pivot. The force on the work side is increased and the force on the work side is reduced, so that the force is balanced. This is an actual phenomenon, and the width reduction amount on the driving side becomes larger than the width reduction amount on the working side due to the rotational movement of the slab. As shown in FIG. This is because the thickness is asymmetrical than the plate thickness on the working side.

FIG. 11 and FIG. 12 are views showing a state when the vicinity of the tail end portion of the slab 2 is being pressed under a width. FIG. 11 shows a hypothetical state in which the balance of forces acting on the slab 2 is ignored. As shown in FIG. 11A, the slab is present at the center of the hot rolling line, so the width reduction amount is equal to the left and right. As shown in FIG. 11B, the exit cross section of the slab is also substantially symmetrical.
However, in this state, the force acting on the slab 2 from the width reduction press tools 1a and 1b is such that the work-side force 15a is larger than the drive-side force 15b due to the lateral difference in deformation resistance (difference between the drive side and the work side). The force acting on the slab cannot be balanced. Therefore, the slab 2 slightly rotates in the direction in which the width reduction amount on the driving side increases with the position of the output side pinch roll 4 constrained in the width direction as a pivot due to the unbalance of the force. The force on the work side is increased and the force on the work side is reduced, so that the force is balanced. This is the actual phenomenon. Due to this rotational movement of the slab, the width reduction amount on the driving side becomes larger than the width reduction amount on the working side, and as shown in FIG. This results in a larger asymmetric shape.

  When a slab having a large thickness on the drive side is horizontally rolled by a subsequent roughing mill after the width reduction press, the reduction rate on the drive side is increased, resulting in a camber on the work side. In the horizontal roll mill, the contact arc length in the longitudinal direction (slab traveling direction) is short, and most of the metal squeezed in the plate thickness direction flows in the longitudinal direction, so uneven rolling in the plate width direction appears as camber. Will do.

  On the other hand, at the front end and tail end of the slab, remarkable camber to the working side occurred after rough rolling, but the camber was very small at the middle portion. This is because the work side deformation resistance is large even in the middle part, and the work side width reduction load is larger than that on the drive side, and the slab is shifted to the drive side. Since the slab is restrained in the width direction by the pinch rolls on the entry side and exit side of the width reduction press tool, even if such a force acts from the width reduction press tool, the front and rear pinch rolls exert their horizontal force. As a result, the slab does not move in the width direction, and as a result, the width reduction on the drive side does not increase as in the case of the slab tip or tail, and the generation of asymmetric dog bones is suppressed. is there.

  The present inventor has invented the following width reduction pressing method and width reduction pressing apparatus for preventing the occurrence of camber, based on the elucidation of the camber generation mechanism accompanying the width reduction pressing operation as described above. And the summary of this invention is as follows.

(1) A width reduction press method using a pair of press tools for reducing the width of a slab and a width reduction press device having a pair of upper and lower pinch rolls on the entry side and the exit side of the press tool,
One set or more that restrains the displacement in the width direction of the slab composed of a pair of vertical rolls that sandwich the width direction of the slab or a pair of pinch rolls that sandwich the thickness direction of the slab, further upstream of the line on the entry side pinch roll The entry side restraint mechanism of
One set or more that restrains displacement in the width direction of a slab composed of a pair of vertical rolls that sandwich the width direction of the slab or a pair of pinch rolls that sandwich the thickness direction of the slab, further downstream of the line on the outlet side pinch roll Has an output side restraint mechanism,
When the length of the shortest slab that performs width reduction by the width reduction press device is L,
The distance from the entrance side restraint mechanism closest to the entrance side pinch roll among the entrance side restraint mechanisms to the exit side restraint mechanism nearest to the exit side pinch roll of the exit side restraint mechanism is longer than L, and < The distance from the entrance side restraint mechanism closest to the entrance side pinch roll among the entrance side restraint mechanisms to the exit side pinch roll is L or less,
Furthermore, the distance from the entry side pinch roll to the exit side restraint mechanism closest to the exit side pinch roll among the exit side restraint mechanisms is L or less,
Even when that width reduction any position to the tail portion from the longitudinal direction of the distal end portion of the slab, at two or more positions in the longitudinal direction of the slab other than the position of the press tool, the said slab width reduction press how, characterized in that to carry out width rolling while constraining the width direction displacement.
(2) A width reduction press device having a pair of press tools for reducing the width of a slab and a pair of upper and lower pinch rolls on the entry side and the exit side of the press tool,
Further line upstream of the inlet side pinch roll, one or more sets for restraining the widthwise displacement of the formed slab with a pair of pinch rolls sandwiching the plate thickness direction of the pair of the vertical roll or slab sandwiching the width direction of the slab The entry side restraint mechanism of
Further line downstream of the outlet side pinch rolls, one or more sets for restraining the widthwise displacement of the formed slab with a pair of pinch rolls sandwiching the plate thickness direction of the pair of the vertical roll or slab sandwiching the width direction of the slab Has an output side restraint mechanism,
When the length of the shortest slab that performs width reduction by the width reduction press device is L,
The distance from the entry side restraint mechanism closest to the entry side pinch roll among the entry side restraint mechanisms to the exit side restraint mechanism nearest to the exit side pinch roll of the exit side restraint mechanism is longer than L and distance to the outlet side pinch roll closest inlet side restraining mechanism before entry side pinch roll of the entry-side restraining mechanism becomes less L,
Furthermore the width reduction press equipment, characterized in that the distance to the nearest exit side restraint mechanism to the outlet side pinch roll is configured to be equal to or less than L of the exit-side restraining mechanism from entering-side pinch rolls.

Here, when the above-described camber generation mechanism is arranged in time series, the following progress is followed.
(A) A left-right temperature deviation of the slab at the time of heating furnace extraction occurs.
(B) A left-right difference in press tool load during width reduction pressing occurs.
(C) The slab moves to the high temperature side.
(D) The width reduction amount on the high temperature side increases.
(E) The plate thickness on the high temperature side is larger than the plate thickness on the low temperature side.
(F) The rolling reduction on the high temperature side in rough rolling increases.
(G) As a result, camber is generated on the low temperature side.

  The width reduction pressing method (1) always performs width reduction in a state where displacement in the width direction of the slab is constrained at two or more locations in the longitudinal direction of the slab. Therefore, (c) in the camber generation process, that is, the slab has a high temperature. Can be prevented from moving to the side. As a result, the phenomenon after (d) does not occur and camber generation can be prevented. As described above, even if there is a left / right difference in the load acting from the width reduction press tool due to the left / right difference in deformation resistance corresponding to the left / right temperature deviation of the slab, the displacement in the width direction is at two or more points in the longitudinal direction of the slab. This is because the width reduction can be performed without translation or rotation of the slab within the plate surface. Here, in order to smoothly move the slab in the line direction even when the width direction restraining force is applied, the width direction displacement restraint is a pair of pinch rolls sandwiching the plate thickness direction of the slab at each restrained place, or It is preferable to carry out with a pair of vertical rolls sandwiching the width direction of the slab (the method of (2) width reduction pressing).

  The width reduction press apparatus of (3) discloses a width reduction press apparatus capable of realizing the width reduction press method of (1). In the width reduction pressing method (1), it is necessary to always restrain the displacement in the width direction at two or more positions in the longitudinal direction of the slab. When the width of the middle part of the slab is reduced, there are pinch rolls for slab feed and slab restraint on the entry side and exit side of the width reduction press device, so the slab can be restrained by these entry and exit side pinch rolls. The movement of the slab in the width direction can be prevented, and an increase in the width reduction amount on the high temperature side can be avoided.

  However, at the time when the slab tip does not reach the exit pinch roll position while the width of the slab tip is being reduced, it is impossible to restrain displacement in the width direction by the exit pinch roll. At this time, when the mechanism for restraining the displacement in the width direction of the slab is only the entry side pinch roll, if there is a temperature deviation of the slab, a lateral difference is caused in the width reduction press load, and as shown in FIG. The slab rotates with the roll position as a fulcrum, and as a result, the width reduction amount on the high temperature side increases relatively, and the plate thickness on the high temperature side becomes relatively large on the exit side of the width reduction press device. The tip camber is generated by rolling at.

  In order to prevent such a rotational movement of the slab, the width reduction press device of the above (3) is provided with an entry side restraining mechanism for restraining the displacement in the width direction of the slab on the upstream side of the line of the entry side pinch roll. This entry side restraint mechanism smoothly moves in the line direction of the slab even in the state where the restraining force in the width direction is applied. Therefore, the pair of pinch rolls sandwiching the thickness direction of the slab or the width of the slab at each restraint point. It is desirable to comprise a pair of vertical rolls that sandwich the direction (the width reduction press device of (4) above).

  Further, when the slab is being reduced in width, the slab is restrained in the width direction at two or more positions in the slab traveling direction. Therefore, when the tail end of the slab comes out of the entry side restraining mechanism, at least the slab tip is It must be restrained in the width direction by the exit side pinch roll. That is, when the length of the shortest slab among the slabs subject to width reduction is L, the distance from the entry side restraint mechanism to the exit side pinch roll needs to be L or less.

  In addition, when the slab tail end part is removed from the entry side pinch roll while the width of the slab tail end part is being reduced, it is impossible to restrain displacement in the width direction by the entry side pinch roll. At this time, when the mechanism for restraining the displacement in the width direction of the slab is only the output side pinch roll, if there is a temperature deviation of the slab, a lateral difference is generated in the width reduction press load, as shown in FIG. The slab rotates with the roll position as a fulcrum, and as a result, the width reduction amount on the high temperature side increases relatively, and the plate thickness on the high temperature side becomes relatively large on the exit side of the width reduction press device. The tail end camber is generated by rolling at.

  In order to prevent such a rotational movement of the slab, the width reduction press device of (3) is provided with an exit side restraining mechanism for restraining displacement in the width direction of the slab on the downstream side of the line of the exit side pinch roll. In order to smoothly move the slab in the line direction even in the state where the width direction restraining force is applied, it is desirable that the exit side restraint mechanism is constituted by a pinch roll or a heel roll (the width reduction press device of (5)). .

  Further, when the slab is being reduced in width, the slab is restrained in the width direction at two or more positions in the moving direction of the slab. Therefore, when the tail end of the slab comes out of the entry side pinch roll, at least the slab tip is It must be restrained in the width direction by the exit side restraint mechanism. That is, when the length of the shortest slab among the slabs subjected to width reduction is L, the distance from the entry side pinch roll to the exit side restraint mechanism needs to be L or less.

  With the width reduction press method and width reduction press apparatus of the present invention, even if there is a left-right temperature deviation in the slab, it is possible to prevent the occurrence of left-right deviation of the width reduction amount, and the camber caused by the width reduction can be substantially eliminated. Thus, the productivity and yield of the subsequent rolling process can be greatly improved.

It is a top view which shows the 1st form of the width reduction press method and width reduction press apparatus concerning this invention. It is a top view which shows the form which is implementing the width reduction press of the front-end | tip part of a short slab in the width reduction press apparatus of the 1st form concerning this invention. It is a top view which shows the form which is implementing the width reduction press of the middle part of a short slab in the width reduction press apparatus of the 1st form concerning this invention. It is a top view which shows the form which is implementing the width reduction press of the tail end part of a short slab in the width reduction press apparatus of the 1st form concerning this invention. It is a top view which shows the 2nd form of the width reduction press method and width reduction press apparatus concerning this invention. It is a top view which shows the 3rd form of the width reduction press method and width reduction press apparatus concerning this invention. It is a top view which shows the 4th form of the width reduction press method and width reduction press apparatus concerning this invention. It is a top view which shows the 5th form of the width reduction press method and width reduction press apparatus concerning this invention. The top view (a) which shows the virtual state which ignored the balance of force at the time of width-squeezing the slab front-end | tip part by the width reduction press method and the width reduction press apparatus of a prior art, and the exit side sectional view of the slab 2 (b) ). The top view (a) which shows the actual state which considered the balance of the force at the time of width-pressing the slab front-end | tip part by the width reduction press method and width reduction press apparatus of a prior art, and the exit side sectional view (b) of the slab 2 It is. The top view (a) which shows the virtual state which ignored the balance of the force at the time of width-squeezing the slab tail end part by the width-reducing press method and the width-reducing press apparatus of the prior art, and the exit side sectional view of the slab 2 ( b). The top view (a) which shows the actual state which considered the balance of the force at the time of width-squeezing the slab tail end part by the width reduction press method and the width reduction press apparatus of a prior art, and the exit side sectional view of the slab 2 (b) ).

Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS.
FIG. 1 is a view showing a first embodiment of a width reduction press method and a width reduction press apparatus according to the present invention. The pair of width reduction press tools 1a and 1b is a mechanism that periodically and continuously performs a reciprocating motion symmetrical with respect to the center line of the hot rolling line in the slab width direction. When the gap between the reduction press tools 1a and 1b becomes small, the slab 2 is reduced in the plate width direction. Further, while the gap between the width reduction press tools 1a and 1b is increased and the width reduction press tools 1a and 1b are separated from the slab 2, the pinch rolls 3 and 4 arranged before and after the width reduction press tools 1a and 1b are used. The slab is fed in the traveling direction 14, and the width reduction is performed when the gap between the width reduction press tools 1a and 1b becomes small again. The plate width reduction of the entire length of the slab is performed by repeating the above process.

  In addition to these, a pair of eaves rolls 8a and 8b and eaves rolls 9a and 9b, which are installed on the side guides 5a and 5b and sandwich the width direction of the slab, are arranged as an entrance side restraint mechanism in addition to these, and the exit side restraint is provided. As a mechanism, a pair of pinch rolls 7 that sandwich the thickness direction of the slab is provided. The heel roll is a set of a pair of left and right rolls, and has a restraining function in the width direction of the slab. In FIG. 1, it is comprised by 2 sets, the heel rolls 8a and 8b, and the heel rolls 9a and 9b.

Since the pinch rolls 3 and 4 also have a function of transporting the slab in the line direction, they are connected to a driving device (not shown). The pinch roll 7 may be non-driven. The pinch roll is a set of a pair of upper and lower rolls, and has a restraining function in the up-down direction, and further has a restraining function in the width direction through a frictional force. For this reason, before entering the slab, the pinch roll waits with the upper and lower roll gaps open. Hold the slab 2. In this invention, the width direction restraint function of a pinch roll is utilized effectively. Further, the distance L ₁ from the entrance side restraint mechanism closest to the entrance side pinch roll, that is, the saddle rolls 8a and 8b to the exit side pinch roll 4, is the length of the shortest slab among the slabs that perform the width reduction by the width reduction press device. L or less, that are arranged such that L ₁ ≦ L. Similarly, the distance L ₂ from the input side pinch roll 3 to the output side restraint mechanism, ie, the pinch roll 7 is also arranged so as to be L or less, that is, L ₂ ≦ L.

  In the embodiment of FIG. 1, the saddle rolls 8a and 8b and the saddle rolls 9a and 9b, which serve as entry side restraint mechanisms, are disposed on the side guides 5a and 5b, so that the position control mechanism in the width direction is shared with the side guides. Therefore, there is an advantage that modification from the existing width reduction press device is easy. Further, since two pairs of heel rolls are arranged in the longitudinal direction, centering of the slab before the width reduction pressing can be smoothly performed through these two pairs of heel rolls.

FIG. 2 is a diagram showing a state in which the width reduction press of the short slab 2 is performed by using the width reduction press apparatus shown in FIG. 1, and particularly shows a state in which the width of the slab tip is being reduced. As described above, the scissors rolls 8a and 8b, the entrance side pinch roll 3 and the exit side pinch roll 4 of the width reduction press device are arranged so as to satisfy L ₁ ≦ L. When the width of the slab is being reduced, the displacement in the width direction of the slab 2 is restricted at least in two longitudinal directions by the entrance pinch roll 3 and the scissors rolls 8a and 8b. However, the slab 2 does not move in the width direction, and as a result, there is no difference between the width reduction amounts.

FIG. 3 shows a situation in which the middle portion of the short slab 2 is being subjected to width reduction by the width reduction press device following the state of FIG. Because of the relationship of L ₁ ≦ L and L ₂ ≦ L, the displacement in the width direction of the slab 2 is always restrained by the input side pinch roll 3 and the output side pinch roll 4 during the width reduction pressing of the middle part. Even if there is a left-right temperature deviation, the slab 2 does not move in the width direction, and as a result, a left-right difference in the width reduction amount does not occur.

FIG. 4 shows a situation in which the tail end portion of the short slab 2 is width-reduced by the width-reducing press device following the state of FIG. Since the pinch rolls 3, 4 and 7 of the width reduction press device are arranged so as to satisfy L ₂ ≦ L, when the width of the slab tail end is reduced as shown in FIG. The displacement in the width direction is constrained by the pinch roll 4 and the pinch roll 7 at two locations in the longitudinal direction. Therefore, even if the slab 2 has a left-right temperature deviation, the slab 2 does not move in the width direction. There is no difference between left and right width reduction.

  As described above with reference to FIGS. 1, 2, 3, and 4, according to the embodiment shown in FIG. 1 of the present invention, even if there is a lateral temperature deviation in the slab, the width by the width reduction press It is possible to prevent the occurrence of camber due to subsequent rough rolling without causing a left-right difference in the reduction amount.

  In the embodiment in the present specification, the slab is fed in the traveling direction while the width reduction press tools 1a and 1b are opened by the pinch rolls 3 and 4 before and after the width reduction press tool. Explained. As another example, there is a width reduction press apparatus in which the slab is fed in the traveling direction when the width rolling press tools 1a and 1b swing in the traveling direction simultaneously with the operation in the width reducing direction. The feeding mechanism in the direction of slab travel is not particularly limited, and the present invention can be similarly applied to such a width reduction press apparatus.

  FIG. 5 is a view showing a second embodiment of the width reduction press device according to the present invention. In the embodiment of FIG. 5, the arrangement of the entrance side scissors roll and the pinch roll is the same as that of the embodiment of FIG. 1, but the exit restraint mechanism is the same as the entrance side and the scissors arranged on the side guides 10 a and 10 b. Rolls 11a and 11b are provided. And since the distance from the entrance side pinch roll 3 to the eaves rolls 11a and 11b is L or less, as explained in FIG. 4, even when the tail end of the slab 2 is width-reduced, the slab 2 Since the displacement in the width direction is restrained by at least the pinch roll 4 and the scissors rolls 11a and 11b, the slab 2 does not move in the width direction even if the slab 2 has a lateral temperature deviation. There is no difference between left and right.

FIG. 6 is a view showing a third embodiment of the width reduction press device according to the present invention. In the embodiment of FIG. 6, the entrance side restraint mechanism is the entrance side pinch roll 6, and the exit side restraint mechanism is the exit side pinch roll 7. The distance L ₁ from the entry side pinch roll 6 to the exit side pinch roll 4 is equal to or less than the length L of the shortest slab among the slabs subjected to width reduction by the width reduction press device, that is, L ₁ ≦ L. Is arranged. Similarly, the distance L ₂ from the entrance side pinch roll 3 to the exit side pinch roll 7 is also set to be equal to or smaller than L, that is, L ₂ ≦ L. Therefore, even in the width reduction press apparatus of FIG. 6, the slab 2 is always subjected to width reduction with the displacement in the width direction being restricted at two or more positions in the longitudinal direction. The slab 2 does not move in the width direction, and as a result, there is no left-right difference in the width reduction amount.

FIG. 7 is a view showing a fourth embodiment of the width reduction press device according to the present invention. In the embodiment of FIG. 7, the entrance side restraint mechanism is the saddle rolls 8 a and 8 b independent of the side guide, and the exit side restraint mechanism is the exit side pinch roll 7. The distance L ₁ from the heel rolls 8a, 8b to the exit side pinch roll 4 is equal to or less than the length L of the shortest slab among the slabs to be subjected to width reduction by the width reduction press device, that is, L ₁ ≦ L. Has been placed. Similarly, the distance L ₂ from the entrance side pinch roll 3 to the exit side pinch roll 7 is also set to be equal to or smaller than L, that is, L ₂ ≦ L. Accordingly, even with the width reduction press apparatus of FIG. 7, the slab 2 is always subjected to width reduction with the displacement in the width direction constrained at two or more positions in the longitudinal direction. The slab 2 does not move in the width direction, and as a result, there is no left-right difference in the width reduction amount.

FIG. 8 is a view showing a fifth embodiment of the width reduction press device according to the present invention. In the embodiment of FIG. 8, the entrance side restraint mechanism is the saddle rolls 8a and 8b independent of the side guides, and the exit side restraint mechanism is the saddle rolls 11a and 11b independent of the side guides. The distance L ₁ from the heel rolls 8a, 8b to the exit side pinch roll 4 is equal to or less than the length L of the shortest slab among the slabs to be subjected to width reduction by the width reduction press device, that is, L ₁ ≦ L. Is arranged. Similarly, the distance L ₂ from the entry-side pinch roll 3 to the eaves rolls 11a and 11b is also set to be L or less, that is, L ₂ ≦ L. Therefore, even with the width reduction press apparatus of FIG. 8, since the width reduction is always performed in a state where the displacement in the width direction of the slab 2 is constrained at two or more positions in the longitudinal direction, even if there is a lateral temperature deviation in the slab 2. The slab 2 does not move in the width direction, and as a result, there is no left-right difference in the width reduction amount.

  In a hot rolling factory in which the width reduction press apparatus of the present invention is arranged upstream of the roughing mill, by carrying out the width reduction press method of the present invention, the occurrence of camber of the rolled plate, which was a drawback of the width reduction press process Can be significantly reduced, and productivity and yield improvement in a hot rolling mill can be achieved. In addition, because the ability of the width reduction pressing process can be utilized to the maximum, the plate width adjustment amount in the hot rolling mill is expanded, the productivity of the continuous casting equipment that is the upstream process is improved, and further, The direct feed rate of the slab to the rolling process is increased, and significant energy saving can be achieved.

DESCRIPTION OF SYMBOLS 1a, 1b Width reduction press tool 2 Slab 3 (entrance side) pinch roll 4 (exit side) pinch roll 5a, 5b (entrance side) side guide 6 (entrance side restraint mechanism) pinch roll 7 (exit side restraint mechanism) pinch roll 8a, 8b (entrance side restraint mechanism) scissors roll 9a, 9b (entrance side restraint mechanism) scissors roll 10a, 10b (exit side) side guide 11a, 11b (exit side restraint mechanism) scissors roll 12a, 12b (exit side restraint mechanism) ) vertical rolls 13a, a force L ₁ inlet side pinch acting on the slab from the width reduction press tool force 15b drive side acts from the width reduction press tool movement direction 14 the slab advancing direction 15a working side of 13b the width reduction press tool in the slab Distance from entry side restraint mechanism closest to roll 3 to exit side pinch roll 4 L ₂ Exit side restraint nearest to exit side pinch roll 4 from entrance side pinch roll 4 Distance to the mechanism L The length of the shortest slab among the slabs to be width-reduced by the width-reducing press

Claims (2)

A width reduction press method using a pair of press tools for reducing the width of a slab, and a width reduction press device having a pair of upper and lower pinch rolls on the entry side and the exit side of the press tool,
One set or more that restrains the displacement in the width direction of the slab composed of a pair of vertical rolls that sandwich the width direction of the slab or a pair of pinch rolls that sandwich the thickness direction of the slab, further upstream of the line on the entry side pinch roll The entry side restraint mechanism of
One set or more that restrains displacement in the width direction of a slab composed of a pair of vertical rolls that sandwich the width direction of the slab or a pair of pinch rolls that sandwich the thickness direction of the slab, further downstream of the line on the outlet side pinch roll Has an output side restraint mechanism,
When the length of the shortest slab that performs width reduction by the width reduction press device is L,
The distance from the entrance side restraint mechanism closest to the entrance side pinch roll among the entrance side restraint mechanisms to the exit side restraint mechanism nearest to the exit side pinch roll of the exit side restraint mechanism is longer than L, and < The distance from the entrance side restraint mechanism closest to the entrance side pinch roll among the entrance side restraint mechanisms to the exit side pinch roll is L or less,
Furthermore, the distance from the entry side pinch roll to the exit side restraint mechanism closest to the exit side pinch roll among the exit side restraint mechanisms is L or less,
Even when any position from the front end to the tail end in the longitudinal direction of the slab is being reduced in width, the slab has two or more positions in the longitudinal direction of the slab other than the position of the press tool. A width reduction pressing method, wherein the width reduction is performed in a state where displacement in the width direction is constrained. A pair of press tools for reducing the width of the slab, and a width reduction press device having a pair of upper and lower pinch rolls on the entry side and the exit side of the press tool,
One set or more that restrains the displacement in the width direction of the slab composed of a pair of vertical rolls that sandwich the width direction of the slab or a pair of pinch rolls that sandwich the thickness direction of the slab, further upstream of the line on the entry side pinch roll The entry side restraint mechanism of
One set or more that restrains displacement in the width direction of a slab composed of a pair of vertical rolls that sandwich the width direction of the slab or a pair of pinch rolls that sandwich the thickness direction of the slab, further downstream of the line on the outlet side pinch roll Has an output side restraint mechanism,
When the length of the shortest slab that performs width reduction by the width reduction press device is L,
The distance from the entry side restraint mechanism closest to the entry side pinch roll among the entry side restraint mechanisms to the exit side restraint mechanism nearest to the exit side pinch roll of the exit side restraint mechanism is longer than L and The distance from the entry side restraint mechanism closest to the entry side pinch roll among the entry side restraint mechanisms to the exit side pinch roll is L or less,
Furthermore, the width reduction press apparatus characterized by the distance from the said entrance side pinch roll to the exit side restraint mechanism nearest to the said exit side pinch roll among the said exit side restraint mechanisms being set to L or less.

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