JPH06315712A - Hot rolling equipment - Google Patents

Abstract

PURPOSE:To sufficiently descale a stock only in front of a finishing mill and to obtain a product excellent in quality without generating indentation flaws by scales. CONSTITUTION:A descaling device 20 composed of a group of rolls 30 and a nozzle 40 is equipped on the upper stream of a finishing mill F1 of a hot rolling equipment 10 which rolls directly a bar stock W cast continuously into <=100mm thickness by heating it in an insulating and heating furnace H to a prescribed temperature through a finishing mill train F. Bending force and tensile force are given by the rolls 31, 32, 33 of this roll group 30 to the bar stock W to make scale easily peeled off and high pressure water is ejected from nozzles 41, 42, 43 to remove scale. In this way, descaling capacity can be increased and a rolled product excellent in quality free from indentation flaws by scale, etc., can be obtained in a hot rolling equipment wherein a thin slab continuous casting machine and a finishing mill are both included.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of hot rolling equipment for directly finish rolling thin slabs of 100 mm or less.
It is designed to be able to perform sufficient descaling upstream of the finishing rolling mill train where there is only a chance of turning.

[0002]

2. Description of the Related Art A hot rolling facility is mainly composed of a rough rolling mill train R (R2, R4) and a finish rolling mill train F (F1, F2, F3, F4) as shown in FIG. It is optimal that the temperature of the strip on the output side of the finishing rolling mill train F is slightly higher than the temperature of the A3 transformation point in the Fe-C equilibrium diagram, and each rolling mill is set to such a temperature. R2, R
The rolling schedule of 4, F1, F2, F3, F4 is determined and hot rolling is performed.

Rough rolling mill train R constituting this hot rolling facility
Has a thickness of 200-250 mm made by a continuous casting machine.
The continuous cast material (slab) of No. 1 is heated to about 1250 ° C. in a heating furnace, and then roughly rolled by a row of rough rolling mills R to a rough bar of 30 mm or less according to the final product thickness of 2 to 5 mm. There are continuous type, fully continuous type, three-water type, etc.

In these rough rolling mill trains R, since it is necessary to remove the scale generated in the slab, descaling devices A, B, C, D, E for injecting high-pressure water for each pass, a pair of horizontal rolls, or A pair of vertical rolls are installed and mechanical descaling with reduction is performed to improve the quality of the final product.

On the other hand, as shown in FIG. 4, a thin slab continuous casting machine TSC, which is an improved continuous casting machine, is used to obtain a thin slab of 100 mm or less as a continuous casting material, and a row of rough rolling machines is omitted, and a heat retaining furnace is provided. Alternatively, after heating to about 1100 to 1050 ° C. in the heating furnace H, the finishing rolling mill train F (F1, F2, F3, F
Hot rolling equipment is being developed to send the product to 4) and roll it to a product thickness of 2 to 5 mm.

By constructing a hot rolling facility by combining such a thin slab continuous casting machine TSC and a heat-retaining furnace or a heating furnace H and a finishing mill train F, it is possible to make the facility significantly compact. There are advantages such as being able to.

[0007]

However, the thin slab continuous casting machine TSC and the finishing rolling mills F1 to F having four to five stands are required.
In the hot rolling equipment in which No. 5 is combined, the bar temperature on the inlet side of the finishing rolling mill train F is higher than the bar temperature of the rough bar sent after being rolled by the roughing mill, and the rolling speed is reduced accordingly.
Due to these, the generation of scale increases.

Therefore, it is necessary to sufficiently perform the descaling, but when there is a rough rolling mill, as shown in FIG. 3, for example, the descaling devices A and B before and after the stands of the rough rolling mills R2 and R4 are used. , C, D have many opportunities for descaling, and there is an opportunity for descaling by the descaling device E even before the finish rolling mill F1, but in the above hot rolling equipment without the rough rolling mill installed, The only opportunity for scaling is the opportunity for descaling by the descaling device E installed in front of the finish rolling mill F1, and since the rolling speed is slow, the temperature drop becomes large if descaling is performed by jetting high-pressure water. Product quality will be reduced.

Further, in the facility in which the thin slab continuous casting machine TSC and the finishing rolling mill train F are combined, the time required for maintaining a uniform temperature in the heat retaining furnace or the heating furnace H is about 5 to 20 minutes. Therefore, the scale layer generated in the thin slab becomes thin, but the mechanical properties of the scale layer are affected by the thickness,
In general, it is known that the thinner the thickness, the stronger and adheres to each other. From this point as well, there is a problem in that sufficient descaling cannot be performed and product quality is significantly deteriorated.

The present invention has been made in view of the above-mentioned problems of the prior art. It is possible to perform sufficient descaling only in front of the finishing rolling mill, to prevent scale indentation scratches, and to improve the quality. It is intended to provide a hot rolling facility capable of obtaining a good product.

[0011]

In order to solve the problems of the prior art, the hot rolling equipment of the first invention is 10
In a hot rolling facility that heats or heats continuously cast material continuously cast to a thickness of 0 mm or less in a furnace and rolls it in a finishing rolling mill train, a bending force or a bending force is applied to the rolled material upstream of the finishing rolling mill train. A descaling device comprising a roll group that applies a bending force and a tensile force and a nozzle that jets high-pressure water is provided in the vicinity of at least one roll of these roll groups.

The hot rolling facility of the second invention is the first rolling mill.
According to the present invention, a rolling roll for applying a light rolling force is provided in place of the roll group provided upstream of the finishing rolling mill train.

[0013]

According to the hot rolling equipment of the first invention, 100 mm
A descaling device consisting of rolls and nozzles should be provided upstream of the finishing rolling mill of the hot rolling facility that directly rolls the continuously cast continuously cast material at a predetermined temperature in the furnace at the finishing rolling mill row. Therefore, a roll group applies bending force or bending force and tensile force to the rolled material to facilitate peeling of the scale, and high-pressure water is jetted from a nozzle to remove the scale.

As a result, the descaling ability can be strengthened as compared with the conventional one, and in a hot rolling facility in which a thin slab continuous casting machine and a finish rolling machine are combined, good quality with no indentation of scale and the like is obtained. Rolled products can be obtained.

Further, according to the hot rolling equipment of the second invention, a rolling roll for applying a light reduction is provided in place of the roll group of the constitution of the first invention, and the light rolling is applied by the rolling roll. Immediately after that, high pressure water is jetted from the nozzle to remove the scale.

Also by doing so, the descaling ability can be strengthened as compared with the conventional one, and in a hot rolling facility in which a thin slab continuous casting machine and a finish rolling machine are combined, there is no indentation of scale. It is possible to obtain a rolled product of good quality.

[0017]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic configuration diagram of only a main part according to an embodiment of the hot rolling facility of the first invention.

This hot rolling equipment 10 comprises a thin slab continuous casting machine TSC (see FIG. 4), a heat retaining furnace or a heating furnace H,
The descaling device 20 and the finish rolling mill train F are configured as main constituent equipment.
It is characterized by the configuration of 0.

That is, the descaling device 20 of the hot rolling equipment 10 is provided with a finishing rolling mill train F downstream of the heating furnace H.
Is installed upstream of the roll bar 30, which is configured to apply a bending force and a tensile force to the rough bar W that is a rolled material, and a nozzle 40 that injects high-pressure water.

As shown in FIG. 1, for example, the roll group 30 is composed of three rolls 31, 32, 33, and the bottom of the roll 32 in the middle is lower than the line connecting the roll tops of the rolls 31, 33 at both ends. It is located so that
A bending force or a bending force and a pulling force can be applied to the coarse bar W passing through the roll group 30.

On the other hand, the nozzle 40 is composed of three nozzles 41, 42 and 43, for example, as shown in FIG. 1, and is coarsely wound around each roll 31, 32 and 33 of the roll group 30 and bent. It is arranged so that high-pressure water can be jetted toward the surface of the bar (rolled material) W.

The descaling device 2 configured as described above
In the hot rolling equipment 10 provided with 0, bending force or bending force and tensile force are applied to the rough bar W passing through the descaling device 20 by the three rolls 31, 32, 33 of the roll group 30, and 150 kg from each of the nozzles 41, 42, 43 of the nozzle 40 in the vicinity where the peeling of the scale generated on the surface of W is promoted and the bending force and the tensile force are applied.
Since high-pressure water of about / cm 2 is jetted, the peeled scale is completely removed from the surface of the rough bar W.

Therefore, as compared with the conventional descaling in which high-pressure water is sprayed from the nozzle, the descaling ability is significantly improved, and the rolled product of good quality can be obtained without causing the scale biting scratches. it can.

As a result, even in a compact hot rolling facility 10 in which a thin slab continuous casting machine and a finish rolling machine are combined, a good quality rolled product can be obtained by descaling upstream of the finish rolling machine.

Next, an embodiment of the hot rolling equipment of the second invention will be described with reference to FIG.

In this hot rolling equipment 50, the roll group 30 of the descaling device 20 of the hot rolling equipment 10 is replaced with a rolling roll 60, and further nozzles 41, 42 are provided downstream of the rolling rolls. The other configurations are the same as those of the hot rolling equipment 10.

The rolling roll 60 of the descaling device 20 constituting the hot rolling equipment 50 is composed of, for example, a pair of upper and lower rolls 61, 62, and is capable of applying a light rolling force. In this case, the mild rolling force may be, for example, a rolling reduction rate of about 1 to 5%,
The value is not such that the coarse bar W is deformed.

A nozzle 40 for injecting high-pressure water is arranged on the outlet side of the rolls 61 and 62, and the rolling roll 6
Immediately after leaving 0, two nozzles 41, 4 are provided above and below the coarse bar W.
High pressure water can be jetted from 2.

The descaling device 2 thus configured
In the hot rolling equipment 50 equipped with 0, a slight reduction force is applied to the rough bar W passing through the descaling device 20 by the upper and lower rolls 61 and 62 of the rolling roll 60, and a scale generated on the surface of the rough bar W. Of each nozzle 41 of the nozzle 40 immediately after the peeling of the
Since high-pressure water of about 42 to 150 kg / cm2 is jetted,
The peeled scale will be completely removed from the surface of the rough bar W.

Therefore, as compared with the conventional descaling in which only high pressure water is jetted from the nozzle, the descaling ability is significantly improved, and biting scratches on the scale do not occur, and a rolled product of good quality can be obtained. it can.

As a result, even in a compact hot rolling facility 50 in which a thin slab continuous casting machine and a finish rolling machine are combined, a good quality rolled product can be obtained by descaling upstream of the finish rolling machine.

The present invention is not limited to the above embodiment,
It goes without saying that each constituent element may be changed without departing from the scope of the present invention.

[0033]

According to the hot rolling equipment of the first aspect of the present invention, as described in detail with reference to the embodiments, the continuous casting material continuously cast to 100 mm or less is heated to a predetermined temperature in a furnace and finished rolling mill. Since a descaling device consisting of rolls and nozzles was installed upstream of the finishing rolling mill of the hot rolling equipment for direct rolling in rows, the rolls apply bending force or bending force and tensile force to the rolled material. Make the scale easy to peel off,
High-pressure water can be jetted from the nozzle in the vicinity thereof to remove the scale.

As a result, the descaling ability can be enhanced as compared with the conventional one, and in a hot rolling facility in which a thin slab continuous casting machine and a finish rolling machine are combined, there is no indentation of the scale and good quality. Rolled products can be obtained.

Further, according to the hot rolling equipment of the second invention, since the rolling rolls for applying the light reduction are provided instead of the roll group of the constitution of the first invention, the light reduction is applied by the rolling rolls. Immediately after that, high-pressure water can be jetted from the nozzle to remove the scale.

Also by doing so, the descaling ability can be strengthened as compared with the conventional one, and in the hot rolling equipment in which the thin slab continuous casting machine and the finish rolling machine are combined, there is no indentation of scale. It is possible to obtain a rolled product of good quality.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of only a main part according to an embodiment of a hot rolling facility of the first invention.

FIG. 2 is a schematic configuration diagram of only a main part according to an embodiment of a hot rolling facility of the second invention.

FIG. 3 is a schematic configuration diagram of a hot rolling facility including a conventional row of rough rolling mills.

FIG. 4 is a schematic configuration diagram of a hot rolling facility including a thin slab continuous casting machine and a finishing rolling mill row to which the present invention is applied.

[Explanation of symbols]

 10 Hot Rolling Facility 20 Descaling Device 30 Roll Group 40 High Pressure Water Jet Nozzle 50 Hot Rolling Facility 60 Rolling Roll F Finish Rolling Mill Row R Crude Rolling Mill Row W Rough Bar (Rolling Material, Continuous Cast Material)

Claims (2)

[Claims] 1. A hot-rolling facility in which a continuous cast material continuously cast to a thickness of 100 mm or less is heat-retained or heated in a furnace and rolled in a finishing rolling mill train, and is rolled upstream of the finishing rolling mill train. A hot rolling characterized in that a descaling device comprising a roll group for applying a bending force or a bending force and a tensile force to a material and a nozzle for injecting high-pressure water in the vicinity of at least one roll of these roll groups is provided. Facility. 2. The hot rolling facility according to claim 1, wherein a rolling roll for applying a light rolling force is provided in place of the roll group provided upstream of the finishing rolling mill train.