JP4853000B2 - Hot rolling method and hot rolling equipment used therefor - Google Patents

Description

The present invention relates to a hot rolling method and hot-rolling facility Ru use therein.

  For example, in thick plate rolling, an excellent steel material is built by performing controlled rolling (CR) during rolling.

  At that time, when the temperature at the time of controlled rolling (controlled rolling start temperature) is low and the plate thickness at the time of controlled rolling (controlled rolling start plate thickness) is thick, the rolled material becomes the controlled rolling start temperature. Since a considerable amount of time is required, the rolled material is kept on standby until the controlled rolling start temperature is reached on the conveyance table in the vicinity of hot rolling (reversible hot rolling mill). As a result, there is a problem that idle time is generated in the hot rolling mill due to the waiting for cooling, and the rolling efficiency is hindered.

In order to avoid that the idle time is generated in the hot rolling mill due to such cooling waiting and the rolling efficiency is hindered, for example, in Patent Document 1, transport is performed on the finishing rolling mill entrance side of the hot rolling line. There is disclosed a standby apparatus for a rolled material including a lifting device having a cantilevered fork-like arm that lifts a hot rolled material on a table to a height that allows the next rolled material to pass through and holds it in a standby state.
JP-A-4-274814

  However, although it has been suggested in Patent Document 1 that overtaking rolling can be performed using a standby device, if a controlled rolling material that requires waiting for cooling is included, how to perform rolling? It is not shown whether the rolling mill efficiency can be improved by reducing the idle time of the hot rolling mill.

The present invention has been made in view of the circumstances as described above, and reduces the idle time of the hot rolling mill and improves the rolling efficiency even when the control rolled material that needs to be cooled is included. it it is an object to provide a hot rolling method and hot-rolling facility Ru using it can.

  In order to solve the above problems, the present invention has the following features.

[1] A reversible heat rolling mill is provided on the upstream side of the reversible hot rolling mill with a holding device as a standby device for lifting the rolled material upward from the transfer table and waiting in a place where the subsequent rolled material can pass. It is a hot rolling method using a hot rolling facility equipped with a cooling device for cooling the rolled material on the conveyance table on the downstream side of the rolling mill,
The first slab is rolled to a predetermined plate thickness by the reversible hot rolling mill and then cooled to a temperature at which control rolling is possible by the cooling device. At the same time, the second slab is cooled by the reversible hot rolling. After rolling, the first slab is fed back to the reversible hot rolling mill at the same time as it is cooled to a temperature that can be controlled and rolled by the holding device as the standby device. Then, rolling to the finished sheet thickness is performed, and the third slab is sent to the reversible hot rolling mill to be rolled to the finished sheet thickness. After the rolling is completed, the second slab is rolled to the reversible hot rolling. A hot rolling method characterized by feeding to a machine and rolling to a finished plate thickness.

[2] A hot rolling facility used in the hot rolling method according to [1],
A reversible hot rolling mill equipped with a holding device as a standby device for lifting the rolled material upward from the transfer table and waiting in a place where the subsequent rolled material can pass on the upstream side of the reversible hot rolling mill. A hot rolling facility comprising a cooling device for cooling the rolled material on the conveying table on the downstream side.

  In the present invention, when a control rolled material that requires waiting for cooling is included, the cooling by the cooling device and the overtaking rolling using the standby device can be appropriately combined. The idle time can be reduced, the number of rolled materials to be rolled can be increased, and the rolling efficiency can be improved.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a layout of a hot rolling facility according to an embodiment of the present invention and a procedure of a hot rolling method using the hot rolling facility. In FIG. 1, 1 is a heating furnace, 2 is a holding device as a standby device, 3 is a reversible hot rolling mill, and 4 is a water cooling device.

  Here, the holding device 2 is provided on the upstream side of the reversible hot rolling mill 3 and holds the high-temperature rolled material by lifting it from the conveying table to a height at which the subsequent rolled material can pass, and reaches a predetermined temperature. It is for making it wait until. Moreover, the water cooling device 4 is provided in the downstream of the reversible hot rolling mill 3, and is for cooling a hot rolling material to predetermined temperature.

  In addition, when rolling the control rolling material in the reversible hot rolling mill 3, the rolling from the slab thickness to the control rolling start plate thickness is called rough rolling, and the control rolling start plate thickness to the finishing plate thickness (after the finish rolling) The rolling up to (sheet thickness) is called finish rolling.

  Then, using these hot rolling facilities, two control rolled materials (first slab A, second slab B) and one normal rolled material (third slab C) are rolled. In this case, the following steps (1) to (6) are performed. Here, the control rolled material is an example of a steel material that needs to wait for cooling, and the normal rolled material is an example of a steel material that does not need to wait for cooling.

  (1) The first slab A extracted from the heating furnace 1 is transported on the transport table, passes through the holding device 2 as it is, and is sent to the reversible hot rolling mill 3. Then, rough rolling is performed by the reversible hot rolling mill 3.

  (2) Subsequently, in synchronism with the progress of the rough rolling of the first slab A in the reversible hot rolling mill 3, the second slab B is extracted from the heating furnace 1, and the holding device 2 is left as it is. It passes through and reaches the reversible hot rolling mill 3 when the rough rolling of the first slab A is completed. The first slab A after the rough rolling is sent to the water cooling device 4 and is temperature-controlled and cooled to a predetermined temperature range suitable for finish rolling. Meanwhile, the second slab B is roughly rolled by the reversible hot rolling mill 3.

  (3) Then, when the rough rolling of the second slab B is completed, the second slab B is sent to the holding device 2 and lifted from the transfer table, and temperature-controlled cooling to a temperature at which control rolling is possible is performed. Be started. At this time, the temperature adjustment cooling in the water cooling device 4 is completed for the first slab A, and the first slab A is fed back and finish-rolled in the reversible hot rolling mill 3.

  (4) When finishing rolling of the first slab A is completed, the first slab A passes through the water-cooling device 4 as it is and is sent to the subsequent refining process.

  (5) Subsequently, while finishing rolling of the first slab A proceeds, the third slab C is extracted from the heating furnace 1 and overwhelms the second slab B lifted to the holding device 2 so as to be reversible. It is sent to the hot rolling mill 3. When the finish rolling of the first slab A is completed, the rolling of the third slab C is started at the same time. When the rolling of the third slab C is completed, the third slab C passes through the water cooling device 4 as it is, It is sent to the refining process.

  (6) Then, when the rolling of the third slab C is completed, the second slab B lifted by the holding device 2 is returned to the transfer table, and the second slab B is transferred to the reversible hot rolling mill 3. Send to roll to finish plate thickness. When the finish rolling of the second slab B is completed, the second slab B passes through the water cooling device 4 as it is and is sent to the subsequent refining process.

  As described above, in this embodiment, when two controlled rolled materials that require cooling and one normal rolled material are rolled, the cooling by the cooling device 4 and the overtaking rolling using the holding device 2 are appropriately combined. Therefore, the idle time of the reversible hot rolling mill 3 can be further reduced, the number of rolled materials to be rolled can be increased, and the rolling efficiency can be further improved.

  In this embodiment, as a standby device for the rolled material, a holding device that lifts and holds the rolled material to a height at which the subsequent rolled material can pass from the transfer table is used. This is because, with such a holding device, it is easy to move the rolled material from the transport table or return the rolled material onto the transport table, but the present invention is not limited thereto. For example, a horizontally moving standby device that moves the rolled material in the horizontal direction from the transfer table so that the subsequent rolled material can pass therethrough may be used.

It is a figure which shows the procedure of the hot rolling method using the layout of the hot rolling equipment which concerns on one Embodiment of this invention, and the hot rolling equipment.

Explanation of symbols

1 Heating furnace 2 Holding device 3 Reversible hot rolling mill 4 Water cooling device

Claims (2)

A reversible hot rolling mill equipped with a holding device as a standby device for lifting the rolled material upward from the transfer table and waiting in a place where the subsequent rolled material can pass on the upstream side of the reversible hot rolling mill. Is a hot rolling method using a hot rolling facility equipped with a cooling device for cooling the rolled material on the conveyance table on the downstream side of,
The first slab is rolled to a predetermined plate thickness by the reversible hot rolling mill and then cooled to a temperature at which control rolling is possible by the cooling device. At the same time, the second slab is cooled by the reversible hot rolling. After rolling, the first slab is fed back to the reversible hot rolling mill at the same time as it is cooled to a temperature that can be controlled and rolled by the holding device as the standby device. Then, rolling to the finished sheet thickness is performed, and the third slab is sent to the reversible hot rolling mill to be rolled to the finished sheet thickness. After the rolling is completed, the second slab is rolled to the reversible hot rolling. A hot rolling method characterized by feeding to a machine and rolling to a finished plate thickness. A hot rolling facility used in the hot rolling method according to claim 1,
A reversible hot rolling mill equipped with a holding device as a standby device for lifting the rolled material upward from the transfer table and waiting in a place where the subsequent rolled material can pass on the upstream side of the reversible hot rolling mill. A hot rolling facility comprising a cooling device for cooling the rolled material on the conveying table on the downstream side.

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