JPH07116704A - Manufacture of hot coil and apparatus therefor - Google Patents

Abstract

PURPOSE:To improve the quality of a coil product manufactured by a rolling mill directly linked to a continuous casting machine. CONSTITUTION:The casting machine 2 is linked to the continuous casting machine 1 and provided at its rear stage. After a slab 11 manufactured by the continuous casting machine 1 is cut off, it is inserted into a heating furnace 12 and the temperature of the slab 11 is adjusted while the moving speed of the slab 11 is increased. Then, the slab 11 is inserted into the rolling mill 2 at a speed 30m/min and rolled. In this way, it is possible to obtain the high- quality coil product free from overlap in of scaling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot coil manufacturing method and apparatus.

[0002]

2. Description of the Related Art As is well known, a typical hot coil manufacturing facility is called a hot strip mill, which has a unit weight of 15 to 50 manufactured by a continuous casting machine.
A facility for reheating a ton slab to about 1100 ° C to 1300 ° C to form a coil, and specifically, for reheating a cold rolled material (slab) manufactured by a continuous casting machine. A king beam heating furnace, a rough rolling mill for rolling the reheated rolled material into a rough bar, a finish rolling mill for rolling the rough bar into a thin plate, and a rolled thin plate (strip). The strip cooling device for cooling and a down coil for winding the cooled thin plate are roughly configured. The primary scale generated during reheating is blown away by the high pressure water spray scaler, and the secondary scale generated during rolling is controlled by the high pressure water spray scaler at the inlet of each rolling mill. It is blown away and removed.

By the way, recently, a facility called "near net shape system" which is an improvement of this hot strip mill and is excellent in yield and energy saving has been proposed and partially implemented (for example, Japanese Patent Publication No. 5-13722). (See Japanese Utility Model Publication No. 61-102301).

This is an equipment in which a continuous casting machine and a rolling mill are continuously provided. This conventional example will be described with reference to FIG. Reference numeral 1 is a curved continuous casting machine, 2 is a rolling machine, both of which are connected via a cutting device 3 and a heating and holding furnace 4. The continuous casting machine 1 is generally composed of a tundish 5, a mold 6 and a roll apron 7, and a rolling mill 2 is a high pressure water spray disker 8, a hot tandem quadruple rolling mill 9 and a coiler 10. It consists of And in such a continuous casting machine direct-connection type rolling mill, the line speed must be adjusted to the slower speed, and the casting speed of the slow continuous casting machine 1 (2 to 3 m / in thick plate slab).
min, about 5 to 6 m / min for a thin plate slab, which is extremely slower than the general rolling speed), and the insertion speed of the rolled material 11 into the rolling mill 2 is halved compared to the general hot strip mill. (Approximately 14m / min at best
).

By the way, the present inventors have conducted a multifaceted analysis of the quality of coil products produced by such a continuous casting machine direct-coupling type rolling mill in comparison with those produced by a general hot strip mill. , I found the following problems.

Generally, when iron comes into contact with oxygen or air at a high temperature, a film of a reaction product, that is, a scale is formed on the surface of the iron. First, oxygen is activated and adsorbed on the iron surface. , The iron surface becomes positive, and oxygen becomes negative ionized, and an extremely thin oxide film is immediately (several seconds) generated due to this potential difference. Therefore, this generated scale
Even if the scale can be blown away with a high-pressure water spray scaler, the internal heat of the rolled material returns to the surface and new scales are generated one after another. Temperature and the time during which the rolled material is in contact with oxygen are greatly affected.

However, as described above, in the continuous casting machine direct-coupling type rolling mill, the speed of insertion of the rolled material 11 into the rolling mill 2 is limited, so that the rolled material can be rolled with the high-pressure water of the high-pressure water spray-disqueler 8. Even if the surface of 11 is cooled, this rolled material 11
Then, the heat recovery to the surface due to the internal heat becomes large,
A new scale is created. As a result, it was found that the newly-formed thick scale layer is wound around the hot coil product itself by the rolling mill 2, and the plastic elongation property of the coil product is significantly deteriorated.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and its gist is as follows: 1) A continuous casting machine is connected to a rolling mill at the subsequent stage. After cutting the slab manufactured by the continuous casting machine, the slab is inserted into a heating furnace and the temperature of the slab is adjusted while increasing the moving speed of the slab in the heating furnace.
There is a hot coil manufacturing method characterized by being inserted into a rolling mill at a speed of n or more and rolling, and 2) directly connected to a continuous casting machine with a continuous casting machine and a rolling machine in the subsequent stage. In the form rolling mill, between the continuous casting machine and the rolling mill,
A hot coil manufacturing apparatus provided with a slab cutting machine and a walking beam heating furnace, and 3) the hot coil manufacturing apparatus according to claim 2, wherein: An apparatus for manufacturing a hot coil, characterized in that a scale breaker for repeatedly bending a plurality of rolls is provided at a subsequent stage.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to an embodiment device shown in the accompanying drawings. FIG. 1 shows an apparatus according to an embodiment of the present invention, and the same or equivalent parts as those of the conventional example shown in FIG.

In the continuous casting machine 1 of the apparatus of this embodiment, the slab as the rolled material 11 has a unit weight of about 50 tons, and the casting speed is about 5 to 6 m / min. The continuous casting machine 1 is not limited to the curved type and may be a twin roll or twin belt type continuous casting machine.

In FIG. 1, the continuous casting machine 1 and the rolling machine 2 are connected via a torch type cutting device 3 and a walking beam type heating furnace 12. This walking beam type heating furnace 12 is a kind of so-called continuous furnace similar to the equipment arranged in the conventional hot strip mill, and is a moving beam that repeats a cycle of rising, traveling, descending, and reverse feeding. The rolling mill 2 is composed of a combination of a beam and a fixed beam, or a combination of moving beams, and a rolling mill 2 at a predetermined speed while laterally feeding a rolled material 11 stored in a heating furnace in a predetermined amount. It is designed to be supplied to. In this example,
A carrier chain may be used in this continuous furnace, in short, as long as the moving speed of the rolled material 11 to the rolling mill 2 can be increased and the rolled material 11 can be supplied to the rolling mill 2 at a desired speed. In FIG. 2, the rolling material 11 manufactured by another continuous casting machine arranged in parallel is stored in another woking beam type heating furnace 12 ′ and is alternately supplied to the same rolling machine 2. Shows.

Further, this walking beam type heating furnace 1
Next to 2, a scale breaker 13 which is repeatedly bent by a plurality of rolls having the same mechanism as the roll leveler is arranged so as to peel off the scale, and then the rolling mill 1
The high-pressure water spray-scaler 8 is arranged in front of the first stand of the above. Further, induction heaters 14, 14 are arranged between the stands of the rolling mill 1 to improve heat retention.

Therefore, according to the apparatus of this embodiment, the rolled material 11 produced by the continuous casting machine 1 at a relatively slow casting speed is cut into a predetermined length by the torch type cutting device 3, and the It is sent to the king beam heating furnace 12. In this woking beam type heating furnace 12, the rolled material 11 is adjusted to a temperature required for rolling as in a normal hot coil mill and is accelerated to a predetermined insertion speed.
For example, increase the insertion speed to at least 30 m / min. In the rolled material 11 thus adjusted, the scale adhered thereto is peeled off by the scale breaker 13, and then the rolled material 11 is removed by the high-pressure water sprayer scaler 8. Immediately thereafter, it is inserted into the rolling mill 2 and formed into a coil. In this embodiment, the rolled material 11 is expressed as a slab, but it goes without saying that this includes billets and blooms.

[0014]

As described above, according to the present invention, since the continuous casting machine and the rolling machine are directly connected and the cast slab is immediately rolled, the yield and the energy saving can be improved as compared with the conventional hot strip mill. Together with improving productivity,
It is possible to obtain coil products of the same quality as or better than those of conventional hot strip mills.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrows a to a in FIG.

FIG. 3 is a conceptual diagram of a conventional continuous casting machine direct connection type rolling mill.

[Explanation of symbols]

1 ... Continuous casting machine, 2 ... Rolling machine, 3 ... Cutting device, 11, 1
1 '... rolled material, 12 ... walking beam type heating furnace, 1
3 ... Scale breaker

Claims (3)

[Claims] 1. A continuous casting machine is provided, and a rolling mill is provided at a subsequent stage of the continuous casting machine. After cutting the slab produced by the continuous casting machine, the slab is inserted into a heating furnace, and the moving speed of the slab is changed in the heating furnace. Adjusting the temperature of the slab while improving, 30m / mi
A method for manufacturing a hot coil, which comprises inserting into a rolling mill at a speed of n or more and rolling. 2. A continuous casting machine direct-coupling type rolling machine which is continuous with the continuous casting machine and is provided with a rolling machine in the subsequent stage, and a slab cutting machine and a walking beer are provided between the continuous casting machine and the rolling machine. An apparatus for manufacturing a hot coil, which is provided with a vacuum heating furnace. 3. The hot coil manufacturing apparatus according to claim 2, wherein a scale breaker for repeatedly bending a plurality of rolls is provided at a subsequent stage of the heating furnace. .