WO2013046345A1

WO2013046345A1 - Hot rolling facility

Info

Publication number: WO2013046345A1
Application number: PCT/JP2011/072141
Authority: WO
Inventors: 亮平木ノ瀬
Original assignee: 三菱日立製鉄機械株式会社
Priority date: 2011-09-28
Filing date: 2011-09-28
Publication date: 2013-04-04

Abstract

In order to provide a hot rolling facility with which the manufacturability of a thin plate material can be effectively increased with little facility investment, this hot rolling facility is equipped with a first rolling line (A), which directly performs finishing rolling with a multi-stage rolling mill (12) on a thin slab (Wa) cast with a continuous-casting machine (10), and a second rolling line (B), which is arranged parallel to the first rolling line (A) and, with a roughing mill (21), reversibly rolls a thick slab (Wb) heated in a batch-type heating furnace (20), with an intermediate material (Wc) that has been rolled with the second rolling line (B) being transported to the first rolling line (A) and undergoing finishing rolling at the first rolling line (A) to produce a final product (S). A slab sizing press (24) that reduces the width of the thick slab (Wb) heated in the batch-type heating furnace (20) is installed in the second rolling line (B).

Description

Hot rolling equipment

The present invention relates to a highly versatile hot rolling facility that can increase the productivity of thin sheet materials more effectively with less capital investment.

Conventionally, a thin slab cast by a continuous casting machine is directly rolled by a plurality of rolling mills, and the first rolling line is arranged in parallel with the first rolling line and heated by a batch heating furnace. A second rolling line for rolling the thick slab with a roughing mill, and transferring the intermediate material rolled in the second rolling line to the first rolling line to finish the final product in the first rolling line. For example, Patent Document 1 discloses a hot rolling facility for rolling.

According to this, by transferring slabs having various slab thicknesses from the second rolling line to the first rolling line, the rear part (soaking furnace, multiple rolling mills, coiler in the first rolling line) Etc.) and can improve the productivity of sheet metal with little capital investment. In the second rolling line, a thick slab is rolled to a slab thickness that can be finished and rolled in the first rolling line with a roughing mill, so that a high-quality sheet material according to demand can be obtained. It is done.

Japanese Patent No. 4001617

However, in the hot rolling facility disclosed in Patent Document 1, various slab thicknesses from the second rolling line to the first rolling line are obtained by the rough rolling line provided with the edger in the second rolling line. However, the second rolling line does not have means for reducing (changing) the width of the slab, so it is necessary to prepare a number of slabs with different widths depending on the plate width of the final product. There was a problem that there was.

That is, the arrangement for each width of the various slabs to be prepared is complicated, and it is troublesome to store the prepared various slabs by the width of the board, and there is a difficulty in versatility.

In addition, when the thick slab is reversibly rolled by the roughing mill in the second rolling line, the temperature of the front and rear ends of the intermediate material is lowered, and shape defects such as fishtail and tongue are generated at the front and rear ends of the intermediate material. There was also a problem that the stability at the final rolling and winding in the rolling line of 1 was lacking and the quality was impaired.

In addition, the rolling of the intermediate material in the second rolling line rolls the material heated in the batch-type heating furnace, so the time from the exiting furnace to the rough rolling varies depending on the position in the longitudinal direction of the material, and the first rolling line There is also a problem in that the stability of the rolling in the first rolling line and the quality of the final product are impaired because the difference occurs in the temperature in the longitudinal direction of the intermediate material transferred to the first rolling line.

The present invention has been proposed in view of such circumstances, and an object thereof is to provide a hot rolling facility that can increase the productivity of a thin plate material more effectively with a small amount of capital investment.

The hot rolling equipment according to the present invention for solving the above problems is as follows.
A slab cast by a continuous casting machine is directly finished and rolled by a plurality of rolling mills, and a slab heated in a batch furnace is arranged in parallel with the first rolling line and heated by a batch heating furnace. A second rolling line that is rolled by a rolling mill, and the intermediate material rolled in the second rolling line is transferred to the first rolling line and hot rolled to finish rolling to the final product in the first rolling line. In rolling equipment,
A slab sizing press for reducing the width of the slab heated in the batch heating furnace is installed in the second rolling line.

Also,
The second rolling line is provided with a crop shearing device for trimming the leading and trailing ends of the intermediate material rolled by the rough rolling mill.

Also,
The plurality of rolling mills in the first rolling line include an upstream rolling mill and a downstream rolling mill each composed of at least one stand rolling mill, and these upstream rolling mill and downstream rolling mill, A crop shearing device that cuts and aligns the front and rear ends of the slab rolled by the upstream rolling mill is installed on the intermediate table.

Also,
The plurality of rolling mills in the first rolling line include an upstream rolling mill and a downstream rolling mill each composed of at least one stand rolling mill, and these upstream rolling mill and downstream rolling mill, A material temperature adjusting device for adjusting the temperature of the slab rolled by the upstream rolling mill is installed on the intermediate table between the two.

According to the hot rolling facility according to the present invention, the maximum utilization of the rear part of the continuous casting machine in the first rolling line can be achieved, and the productivity of the thin plate material can be improved with less equipment investment. In the second rolling line, a thick slab can be rolled to a slab thickness that can be finished and rolled in the first rolling line with a roughing mill, so that a high-quality sheet material according to demand can be obtained. By adding a slab sizing press to the rolling line, the coil width produced in the first rolling line can be changed in various ways with the minimum slab width type, which can further improve the productivity of thin plate materials and versatility. High-quality equipment can be realized.

In addition, since a crop shearing device is installed in the second rolling line to cut the leading and trailing ends of the intermediate material reversibly rolled by the roughing mill, the leading and trailing end shapes of the intermediate material rolled in the second rolling line are installed. Defects and temperature-decreasing parts can be cut before being transferred to the first rolling line, stability in the final rolling and winding in the first rolling line is ensured, and quality and productivity are impaired. Can be prevented.

The rolling mill in the first rolling line is composed of an upstream rolling mill and a downstream rolling mill each composed of at least one stand rolling mill. Since the crop shearing device that cuts and aligns the leading and trailing ends of the slab rolled by the upstream rolling mill is installed in the intermediate table in the middle, even if there is no crop shearing device in the second rolling line, the intermediate material is the first material. After transfer to the rolling line, the leading and trailing edge shape defects and the temperature drop part can be cut, the stability in the final rolling and winding in the first rolling line is ensured, and the quality and productivity are impaired. Can be prevented.

The rolling mill in the first rolling line is composed of an upstream rolling mill and a downstream rolling mill each composed of at least one stand rolling mill. Since the material temperature adjusting device for adjusting the temperature of the slab rolled by the upstream rolling mill is installed in the intermediate table, the temperature difference in the longitudinal direction of the intermediate material produced in the second rolling line is Rolling at a more uniform temperature can be carried out with a material temperature control device in one rolling line, the stability of the final rolling in the first rolling line can be ensured, and the loss of quality and productivity can be prevented. .

It is a schematic structure side view of the hot rolling equipment showing Example 1 of the present invention. It is a schematic structure side view of the hot rolling equipment showing Example 2 of the present invention. It is a schematic structure side view of the hot rolling equipment showing Example 3 of the present invention. It is a schematic structure side view of the hot rolling equipment which shows Example 4 of this invention.

Hereinafter, the hot rolling equipment according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic side view of a hot rolling facility showing Example 1 of the present invention.

As shown in FIG. 1, molten steel is poured from a ladle (not shown) into the tundish, and from the tundish to the continuous casting machine 10. The molten steel is solidified in the continuous casting machine 10 and becomes a high-temperature thin slab Wa (for example, about 70 to 100 mm). The thin slab Wa proceeds to a soaking furnace (continuous casting machine outlet furnace) 11, where the temperature drop of the thin slab Wa is suppressed, and the temperature distribution in the thin slab Wa is made uniform. . Further, on the exit side of the continuous casting machine 10, a shear (not shown) is provided for cutting when the slab reaches a desired length.

The thin slab Wa exiting from the soaking furnace 11 is finish-rolled by a plurality of rolling mills 12 (six (6 stands) in the illustrated example) to form a strip S having a desired thickness (for example, about 1 mm to 10 mm). After being rolled, it is wound up alternately by downcoilers 13 arranged in a plurality (two in the illustrated example) through a cooling device (not shown). A first rolling line A is constituted by the continuous casting machine 10, the soaking furnace 11, a plurality of rolling mills 12, a downcoiler 13, and the like. A carousel coiler may be used instead of the plurality of down coilers 13.

Then, a second rolling line B is arranged in parallel with the first rolling line A. In the second rolling line B, a thick slab Wb (for example, about 200 to 250 mm) heated in a batch-type heating furnace 20 such as a walking beam furnace is applied to a desired thickness (for example, the first rolling) by a roughing mill 21. Rough rolling is carried out reversibly up to a thickness equivalent to the thickness of the thin slab Wa in the line A).

The intermediate material Wc rolled in the second rolling line B is transferred (transversely fed) to the soaking furnace 11 of the first rolling line A by a transfer furnace (transfer) 22 and multistage in the first rolling line A. The rolling mill (row) 12 is finished and rolled to the final product strip S. The transfer furnace 22 is also a part of the heating furnace. Further, the transfer furnace 22 may be in a form other than the lateral feed, for example, a rotary type. Further, an edger mill 23 for adjusting the width of the thick slab Wb is installed in the vicinity of the upstream side of the rolling line of the roughing mill 21.

In this embodiment, the second rolling line B is heated between the batch heating furnace 20 and positioned between the batch heating furnace 20 and the roughing mill 21 (strictly, the edger mill 23). A slab sizing press (SSP) 24 for reducing the width of the thick slab Wb is installed.

The slab sizing press 24 is capable of rolling down a width of about 350 mm at maximum in one pass by intermittently rolling the slab with a trapezoidal mold. By the way, it is known that a general vertical roll (VSB) that performs width reduction using a roll having a diameter of about 1000 mm can only perform width reduction of about 100 mm / pass due to biting restrictions.

Since it is comprised in this way, the intermediate raw material Wc rolled by the 2nd rolling line B is transferred to the 1st rolling line A, and it is a final product with the several rolling mill 12 of the said 1st rolling line B. Since the finish rolling is performed up to the strip S, the maximum utilization of the rear part (the soaking furnace 11, the plurality of rolling mills 12, the downcoiler 13, etc.) behind the continuous casting machine 10 in the first rolling line A can be achieved. The productivity of the strip S (thin plate material) can be improved with a small capital investment.

Further, in the second rolling line B, the thick slab Wb can be rolled to a slab thickness (for example, about 70 to 100 mm) that can be finished and rolled in the first rolling line B by the rough rolling mill 21. The casting machine 10 can obtain a high-quality strip S (thin plate material) according to demand, for example, by procuring a thick slab of a steel type that is difficult to cast from the outside.

Further, by adding the slab sizing press 24 to the second rolling line B, the intermediate material Wc supplied to the first rolling line A is optimized according to the width of the strip S as the final product. Can be produced in the second rolling line B, and the coil width produced in the first rolling line A can be changed in various ways with the minimum slab width, which further increases the productivity of the strip S (thin plate material). As well as highly versatile equipment.

That is, conventionally, in the second rolling line B, there is no width changing means, or one having a small width reduction capability such as a vertical roll is installed. Further, since the first rolling line A is directly connected to the continuous casting machine 10, it is difficult to change the width. Therefore, it is necessary to prepare a thick slab Wb having the same kind of width as the strip S as the final product, and the arrangement of the various slabs to be prepared is complicated, and the prepared various slabs are stored by type. However, it was troublesome and there was a difficulty in versatility, but it was solved. Furthermore, the product of the most widely produced sheet width is rolled exclusively in the first rolling line A, and the products of various other sheet widths are rolled in the second rolling line B. The productivity of A can be improved.

FIG. 2 is a schematic side view of the hot rolling equipment showing Example 2 of the present invention.

In this embodiment, as shown in FIG. 2, the intermediate material rolled on the second rolling line B in the first embodiment is located in the vicinity of the downstream side of the rolling line of the roughing mill 21 and rolled by the roughing mill 21. (Slab) This is an example in which a crop shearing device 30 </ b> A for trimming the front and rear ends of Wc is installed. Since other configurations are the same as those of the first embodiment, the same members as those in FIG.

According to this embodiment, in addition to the same effects as those of the first embodiment, the leading and trailing edges of the intermediate material Wc rolled in the second rolling line B have poor shape (fishtail, tongue, etc.) and the temperature drop at the leading and trailing edges. The portion can be cut before being transferred to the first rolling line A so that the planar shape is rectangular, whereby the final rolling by the multi-stage rolling mill (row) 12 in the first rolling line A Stability in winding by the downcoiler 13 is ensured, and there is an advantage that it is possible to prevent the quality and productivity from being impaired.

FIG. 3 is a schematic side view of a hot rolling facility showing Example 3 of the present invention.

In this embodiment, as shown in FIG. 3, a plurality of rolling mills 12 in the first rolling line A in the first embodiment are divided into upstream rolling mills 12a and 1 each composed of one or more stands (two stands in the illustrated example). The upstream rolling mill 12a is divided into a downstream rolling mill 12b composed of the above stands (5 stands in the illustrated example), and the upstream rolling mill 12a is arranged on an intermediate table between the upstream rolling mill 12a and the downstream rolling mill 12b. This is an example in which a crop shearing device 30B for cutting and aligning the front and rear ends of the slab roughly rolled in step (thin slab Wa or intermediate material Wc) is installed.

Other configurations include a scale removing device 31A for removing the oxide scale on the surface of the slab (thin slab Wa or intermediate material Wc) in order from the upstream side of the rolling line on the entrance side of the upstream rolling mill 12a and a longitudinal as a width changing means. While installing the roll 32, the scale removal apparatus 31B which removes the oxide scale of the surface of the slab (thin slab Wa or intermediate material Wc) by which the front-and-rear end was cut | disconnected by the crop shear apparatus 30B at the entrance side of the downstream rolling mill 12b. Since it is the same as that of Example 1 except having installed, the same code | symbol is attached | subjected to the same member as FIG. 1, and the overlapping description is abbreviate | omitted.

According to this embodiment, in addition to the same effects as those of the first embodiment, the front and rear end shape defects (fishtail, tongue, etc.) of the thin slab Wa rolled in the first rolling line A and the temperature drop of the front and rear ends are reduced. Cut the portion and the leading and trailing end shape defects (fishtail, tongue, etc.) of the intermediate material Wc rolled in the second rolling line B and the temperature decreasing portion of the leading and trailing ends at the inlet side of the downstream rolling mill 12b. The planar shape can be made rectangular, which ensures stability in the final rolling by the downstream rolling mill 12b in the first rolling line A and the winding by a plurality of downcoilers 13, and the quality and productivity. Can be prevented.

FIG. 4 is a schematic side view of a hot rolling facility showing Example 4 of the present invention.

In this example, as shown in FIG. 4, instead of the crop shear device 30B, an intermediate table between the upstream rolling mill 12a and the downstream rolling mill 12b of the first rolling line A in Example 3, This is an example in which a material temperature adjusting device 40 for adjusting the temperature of the slab (thin slab Wa or intermediate material Wc) rolled by the upstream rolling mill 12a with cooling water, a heating device or the like is installed. Since other configurations are the same as those of the third embodiment, the same members as those in FIG.

According to this example, in addition to the same effects as in Example 3, the temperature difference in the longitudinal direction of the intermediate material Wc produced in the second rolling line B is adjusted in the material temperature in the first rolling line A. Rolling at a more uniform temperature can be performed with the apparatus 40, the stability of the final rolling in the first rolling line A is ensured, and the advantage that the quality and productivity can be prevented from being lost is obtained.

That is, the rolling of the intermediate material Wc in the second rolling line B rolls the thick slab Wb heated in the batch-type heating furnace 20, so that the time from the furnace to the rough rolling in the rough rolling mill 21 is thick slab. Depending on the position in the longitudinal direction of Wb and the difference in the longitudinal temperature of the intermediate material Wc transferred to the first rolling line A, the rolling stability and final product quality in the first rolling line A can be improved. There was a problem of losing, but it was solved. Incidentally, since the thin slab Wa cast in the first rolling line A is heated in the soaking furnace 11, the temperature during rolling in the longitudinal direction is substantially uniform.

In the present embodiment, as in the third embodiment, the upstream rolling mill 12a is adjacent to the material temperature adjusting device 40 on the intermediate table between the upstream rolling mill 12a and the downstream rolling mill 12b. Needless to say, a crop shearing device 30B (see FIG. 3) for trimming the front and rear ends of the slab (thin slab Wa or intermediate material Wc) roughly rolled in step S1 may be installed.

The hot rolling facility according to the present invention can achieve the maximum utilization of the rear portion (the soaking furnace 11, the plurality of rolling mills 12, the downcoiler 13, etc.) behind the continuous casting machine, and therefore the manufacturing equipment for the thin plate material It is suitable for use.

10 Continuous casting machine 11 Soaking furnace (continuous casting machine outlet furnace)
12 Multi-stage rolling mill (row)
12a Upstream rolling mill 12b Downstream rolling mill 13 Downcoiler 20 Batch heating furnace 21 Rough rolling mill 22 Conveying furnace (transfer)
23 Edger Mill 24 Slab Sizing Press (SSP)
30A, 30B

Crop shear device

31A, 31B Scale removal device 32 Vertical roll 40 Material temperature control device A 1st rolling line B 2nd rolling line Wa Thin slab Wb Thick slab Wc Intermediate material S Strip

Claims

A slab cast by a continuous casting machine is directly finished and rolled by a plurality of rolling mills, and a slab heated in a batch furnace is arranged in parallel with the first rolling line and heated by a batch heating furnace. A second rolling line that is rolled by a rolling mill, and the intermediate material rolled in the second rolling line is transferred to the first rolling line and hot rolled to finish rolling to the final product in the first rolling line. In rolling equipment,
A hot rolling facility characterized in that a slab sizing press for reducing the width of the slab heated in the batch heating furnace is installed in the second rolling line.
2. The hot rolling facility according to claim 1, wherein a crop shearing device is provided in the second rolling line for trimming the leading and trailing ends of the intermediate material rolled by the roughing mill.
The plurality of rolling mills in the first rolling line include an upstream rolling mill and a downstream rolling mill each composed of at least one stand rolling mill, and these upstream rolling mill and downstream rolling mill, The hot rolling facility according to claim 1, wherein a crop shearing device is provided in an intermediate table between the two, wherein a crop shearing device that cuts the leading and trailing ends of the slab rolled by the upstream rolling mill is installed.
The plurality of rolling mills in the first rolling line include an upstream rolling mill and a downstream rolling mill each composed of at least one stand rolling mill, and these upstream rolling mill and downstream rolling mill, 4. The hot rolling facility according to claim 1, wherein a material temperature adjusting device for adjusting a temperature of a slab rolled by the upstream rolling mill is installed in an intermediate table.