JP2002035801A - Charging method of continuously casting hot slab into heating furnace for hot rolling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means to lower a fuel standard physical unit of a heating furnace for hot rolling in 'a straight forward rolling for a hot cast slab' hot rolled after charging the hot slab continuously cast without being cooled into the heating furnace for hot rolling. SOLUTION: Each hot slab cast by plural group of continuous casters flows into each other in the optimized.transfer line of the hot east slab joining a slab caster and the heating furnace for hot rolling, and concurrently the transfer order control of the hot slab is performed in the optimized pretreatment and transfer line in accordance with the rolling schedule (preferably performed at the meeting point of the hot slab) and the charging of the hot cast slab into the heating furnace for hot rolling is executed in the transfer order of the control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for charging a continuously cast hot slab into a hot rolling furnace for reducing the fuel consumption rate of the hot rolling furnace.

[0002]

2. Description of the Related Art Conventionally, in order to reduce the unit fuel consumption of a heating furnace in a hot rolling line, a continuously cast slab has been conventionally sent directly to a heating furnace for hot rolling without cooling in a high temperature state. So-called "direct charging" is performed. However, the slab supply capacity per unit of continuous casting equipment is smaller than the hot rolling capacity, so that the shortage of slab supply capacity must be compensated for by cold slabs. (Ratio of direct charge to hot rolling) was limited.

[0003] In recent years, in order to solve the shortage of hot slab supply capacity, a large number of slabs are manufactured in parallel by a plurality of continuous casting facilities, and these are directly sent to a heating furnace for hot rolling. Efforts have been made to increase the direct charge ratio. However, when a plurality of continuous casting facilities are used, it is difficult to timely charge each of the hot slabs produced by each facility to the heating furnace for hot rolling. By this time, the amount of temporary placing in the waiting queue increased, and eventually the effect of reducing the fuel consumption per unit of heating furnace by direct feeding of hot slab could not be fully utilized.

Therefore, Japanese Patent Application Laid-Open No. 59-6324 discloses that a plurality of slab production facilities are installed on a line directly connecting a steelmaking factory as an upper step and a hot rolling factory as a lower step.
Along with operating these slab production facilities so that the slabs are produced by wrapping each other, the slabs produced by the plurality of slab production facilities are each heated to a specific heating furnace for each slab production facility. The hot slab is continuously charged (ie, the slab obtained in the slab manufacturing facility A is placed in the heating furnace a,
The slab obtained in the above is charged into the heating furnace b).

[0005] However, this method is characterized in that each slab obtained by a plurality of slab production facilities is charged into a specific heating furnace on a facility basis, so that the rolling order is maintained in the casting order. Although it is possible, the irregular rolling schedule cannot be properly dealt with, and in such a case, it is necessary to adjust the rolling order (extracting order) of the slab after charging the heating furnace. Therefore, there has been a problem that the heating furnace basic unit in hot rolling is worsened than the operation using a single-unit slab manufacturing facility.

In view of the above, an object of the present invention is to provide a "direct-charging" method in which a continuously cast hot slab is charged into a heating furnace for hot rolling without cooling and then hot-rolled. In the “rolling”, it was to establish a means for reducing the unit fuel consumption of the heating furnace for hot rolling as much as possible.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and has the following "method of charging a continuously cast hot slab into a heating furnace for hot rolling". To provide. Each of the hot slabs cast by the plurality of continuous casting facilities is joined by a slab refining / transport line connecting the slab casting facility and a heating furnace for hot rolling, and is combined with a rolling schedule. The transfer order control of hot slabs
Performed on a transfer line, characterized in that the charging of the hot slab to the heating furnace for hot rolling is carried out in the transfer order in which the above control was performed, to the heating furnace for hot rolling of continuous casting hot slab How to charge. The above-mentioned item, wherein the control of the transport order of the hot slabs according to the rolling schedule is performed at a point in time when the hot slabs cast by the plurality of continuous casting facilities are merged in the refining / transport line. For charging a continuous cast hot slab to a heating furnace for hot rolling.

[0008] That is, the present invention provides a hot rolling mill in which a plurality of dedicated slab production facilities for hot rolling are installed on a line directly connecting a steelmaking factory as an upper step and a hot rolling factory as a lower step. In the method for directly feeding and supplying the hot slab produced by the slab production facility, a refining / conveying line (connected by a roller table) located between the casting facility and a hot rolling heating furnace. Sizing mill, hot scarfer, shear,
When a hot slab passes through a measuring / engraving device, a trolley, etc.), more preferably, when the hot slabs cast by a plurality of slab slab manufacturing equipment are joined by a refining / transport line. It has a great feature in that "rolling schedule (rolling schedule)" is adjusted by means of a slab transfer / placement device such as a crane to "control the order of transport of hot slabs". .

[0009]

According to the method of the present invention, each hot slab which has been cast by a plurality of continuous casting facilities and cut to a predetermined size is passed through a "refining / transfer line directly connected to a hot rolling mill". The transfer order control according to the rolling schedule in the cold rolling mill is performed, and they are merged into one. And
The hot slabs, which have been controlled in the transfer order, are transferred to a heating furnace for hot rolling in a hot rolling factory via a slab transfer device (roller table, cart, etc.), and the controlled transfer is performed. It is charged into a heating furnace in order. Therefore, the hot slabs in the heating furnace for hot rolling are arranged in accordance with the rolling schedule.
And the deterioration of the heating furnace fuel consumption rate does not occur.

Further, according to the method of the present invention, the hot slab is conveyed to the heating furnace for hot rolling in an order conforming to the rolling schedule, so that the method described in the above-mentioned JP-A-59-6324 is used. As described above, there is no need to specify a heating furnace by individual continuous casting equipment, no time loss at the time of charging the heating furnace, and no problem of heat loss due to temporary placement. Therefore, from this point as well, the heating furnace fuel consumption rate of the hot rolling factory is reduced, and the productivity of the hot rolling factory is also improved.

It is to be noted that the transfer order control of the hot slabs according to the rolling schedule is preferably performed at the time when the hot slabs cast by a plurality of continuous casting facilities are merged in a refining / conveying line. good. Because, at this point, if the transport order control is performed, it is possible to simultaneously perform “merging of the slabs manufactured in the respective continuous casting facilities” and “arranging in the transport order”. After the merging, the slabs are moved again and arranged. This is because there is no need to change them.

Next, the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of the present invention. In this embodiment, two dedicated slab production facilities (one-strand continuous casting facilities A and 2) for hot rolling are provided on a line directly connecting a steelmaking factory as an upper step and a hot rolling factory as a lower step. An equipment arrangement with a continuous strand equipment B) is employed.

[0013] Note that one slab cutting device in a slab production line of continuous casting equipment A strand (cut bets - h) 1 _1,
The 2 strands of the slab cutting device in a slab production line of continuous casting equipment B (cut bets - h) 1 ₂ and 1 ₃ are arranged, also 2 strands of continuous casting facilities B
A cradle for transferring the “hot slab produced by the slab production equipment” to the slab refining and conveying line
(Not shown). Then, the finishing line and conveying line of the slab manufacturing facilities and hot rolling heating furnace 7 ₁ and 7 ₂ connecting slab, sizing mill 2, Hottosuka - fa -3, Shah -4, weighing and stamping device 5, dolly 6 ₁
6 ₃ and the like are arranged.

[0014] Now, in the equipment shown in FIG. 1, first heat slab cut by the cast strip cutting device 1 ₁ out of the continuous casting facilities A strand, 2 strands of continuous casting facilities B
Kure disposed in the line of - the "slab of finishing line-transfer line" heat slabs cut by 2 continuous casting equipment out to cast strip cutting device from B 1 ₂ strands, 1 ₃ by emissions And join them.

Heretofore, conventionally, the hot slabs produced by the slab production equipment have been transported as they are to the heating furnace for hot rolling or the temporary yard in the order of production. A
And the hot slab from the continuous casting equipment B
When the slabs are merged at the "slab sizing / transportation line" by means of a roll or the like, "transport order control according to the rolling schedule" is performed. The transfer order control of the hot slabs according to the rolling schedule may be performed after the hot slabs from the respective continuous casting facilities are merged, but in this case, a slight reduction in workability cannot be denied.

Then, the hot slabs, which have been joined and controlled in the transfer order according to the rolling schedule, are passed through a "slab refining / transfer line" leading to a hot rolling mill, and are used as a heating furnace for hot rolling. It is conveyed to 7 ₁ and 7 ₂ , and is directly loaded into the hot rolling heating furnaces 7 ₁ and 7 _{2 in the} order of conveyance.

As described above, according to the method of the present invention, the hot slab from the continuous casting facility is charged into the heating furnace for hot rolling via the "slab refining / conveying line" following the hot rolling mill. Until this is done, the "conveying sequence control of hot slabs according to the roll schedule" is performed, so that the heating furnace for hot rolling is transferred to the heating furnace one after another without specifying it. Even after loading the hot slab, it is possible to sequentially take out and roll it after a specified time, perform the selection of the hot slab to be taken out of the heating furnace at the time of rolling, or heat the hot slab before loading it into the heating furnace. There is no need to temporarily store the files. Therefore, the hot slab does not have to be heated and held for an unnecessary time in the heating furnace, and the temperature of the hot slab does not have to be unnecessarily lowered due to the temporary placement. Furnace fuel intensity is greatly reduced.

FIG. 2 shows the "Example of the present invention" in which the transfer order control of the hot slab was performed as described above and the "Comparative Example in which the transfer order control was not performed (see Japanese Patent Application Laid-Open No. 59-6324). 2) is a graph comparing the fuel consumption rate of the heating furnace for hot rolling with “Method)”. The “heating furnace fuel consumption rate index” in FIG. 2 is a ratio of the heating furnace fuel consumption rate when the heating furnace fuel consumption rate in “Comparative Example” is set to “1”. As can be seen from FIG. 2, according to the method of the present invention, it is possible to reduce the fuel consumption index by more than 0.2 as compared with the comparative example.

[0019]

As described above, according to the present invention, it is possible to greatly reduce the unit fuel consumption of the heating furnace for hot rolling in hot slab direct rolling, without requiring a large-scale equipment change. And other industrially useful effects.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a graph comparing heating furnace fuel consumption for hot rolling in an example of the present invention (an example in which transport order control is performed) and a comparative example (an example in which transport order is not controlled).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ₁ Slab cutting device 1 ₂ Slab cutting device 1 ₃ Slab cutting device 2 Sizing mill 3 Hot scarfer 4 Shar 5 Weighing and marking device 6 ₁ truck 6 ₂ truck 6 ₃ truck 7 ₁ Heating for hot rolling Furnace 7 ₂ Heating furnace for hot rolling

Continued on the front page. (72) Inventor, Misao Kumasaka, 3 Oaza, Kashima-shi, Ibaraki Prefecture Sumitomo Metal Industries, Ltd. Kashima Works F-term (reference) 4E002 AA05 BD02 CB07 CB08 4K034 AA12 BA08 CA01 CA02 DA08 DB05

Claims (2)

[Claims] 1. A hot slab cast by a plurality of continuous casting facilities is joined by a slab refining / transfer line connecting a slab casting facility and a heating furnace for hot rolling, and rolling is performed. The transfer order control of the hot slabs according to the schedule is performed on this refining and transfer line, and the charging of the hot slabs to the heating furnace for hot rolling is performed in the transfer order in which the above control is performed. A method for charging a continuously cast hot slab to a heating furnace for hot rolling. 2. The method according to claim 1, wherein the control of the transport order of the hot slabs according to the rolling schedule is performed at a point in time when the hot slabs cast by the plurality of continuous casting facilities are merged in a refining / transfer line. A method for charging a continuously cast hot slab according to claim 1 into a heating furnace for hot rolling.