JPS6356301A - Equipment for hot production of steel strip - Google Patents

Abstract

PURPOSE:To suppress the generation of a camber and to improve the dimensional accuracy of a product by providing side guides to one or both on the inlet or outlet side of a surface light draft mill disposed to continuous casting equipment, thereby guiding the progression of a thin slab strand. CONSTITUTION:The side guides 16 are installed on the front of the surface light draft mill and the similar side guides 17 on the rear thereof. These side guides 16, 17 are connected to driving devices which can move the side guides back and forth in the direction orthogonal with the progressing direction of the thin slab. While the side guides are moved back and forth, the side guides are pressed to both sides of the strand of the slab 6 to guide the progression. The dimensional accuracy of the product is improved by he device constituted in the above-mentioned manner.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to hot steel strip manufacturing equipment that is advantageous for directly hot finish rolling a thin slab cast to a thickness of 20 to 50 mm. It is.

(Prior art) In general, the process of manufacturing hot steel strip involves reheating a slab with a thickness of 100 to 300 mm produced by a continuous casting machine, and then rolling it into a rough bar of 20 to 50 mm in a hot rough rolling mill. Roll. And 1.2~ with 6~7 finishing rolling mills
The process consists of finishing it to a thickness of 20 mm, spray cooling it, and winding it up with a down coiler.

On the other hand, in recent years, a new continuous casting machine has been developed to manufacture sheet bars having a thickness of about 20 to 50 mm by continuous casting. The sheet bars manufactured with this equipment are at high temperatures and contain a large amount of thermal energy, so by directly finishing rolling them, there is no need to reheat them (a large reduction in thermal energy and the slab can be made to a rough par thickness). It is possible to drastically reduce the electric power required for rolling to a maximum of 1000 yen.In addition, due to the complete continuous synchronization of the continuous casting process and hot rolling process, delivery times can be shortened, equipment costs can be significantly reduced, and the number of required personnel can be reduced. This is a great advantage.

With recent developments in continuous casting equipment for thin slabs,
However, in order to realize the continuous process of continuous casting lines and hot rolling lines, there are many problems other than the new continuous casting machine itself as mentioned above, and it is necessary to add new functions that were not available before. In addition, it was necessary to develop a line of equipment that could realistically be produced.

In an attempt to achieve complete continuous synchronization between the continuous casting process and the hot rolling process, for example, Japanese Patent Laid-Open No. 55-133803 discloses that there is Providing a temperature control device and a coil box,
Further, Japanese Patent Application Laid-Open No. 108101/1983 discloses that a thin cast piece is formed into a coil, held in an insulated and soaked furnace, and the coil is unwound and hot rolled.

Also, JP-A-55-147402 and JP-A-58-1
In addition to the continuous process of continuous casting and hot rolling, Publication No. 12603 proposes installing a width reduction device downstream of the continuous casting equipment in order to change the thickness of the thin slab obtained in the casting process. has been done.

(Problems to be Solved by the Invention) By the way, the continuous casting equipment for thin slabs currently under development, as proposed in JP-A-58-32551, applies static pressure to the back of the metal belt. Many of them are equipped with a type of mold that forms a supporting water film and solidifies molten steel through this metal belt.

For this reason, the obtained thin slab has irregular thickness deviations in the middle direction, and when this is directly hot rolled,
There are problems such as camber occurring during rolling, leading to deterioration of product quality, and currently there remains a major obstacle to establishing a continuous process from continuous casting to hot rolling.

An object of the present invention is to propose a hot steel strip production facility that is advantageous in solving the conventional problems that have been an obstacle when establishing the above-mentioned continuous process.

(Means for Solving the Problems) The present inventors conducted an experimental study on the camber of the rolled material at the entrance and exit sides of the mill using a 1/10 model machine using lead as the material to be rolled. It has been found that by restraining the side edges of the rolled material at the entrance and exit sides of the mill, cross flow due to metal flow is generated during rolling, and the camber can be easily corrected.

That is, the present invention provides hot steel strip manufacturing equipment that combines a continuous casting equipment for manufacturing thin slabs and a rolling equipment for directly hot rolling the obtained thin slabs. This hot steel strip production equipment is characterized in that side guides are provided on the entry side, the exit side, or both sides of a surface light reduction mill to abut on both sides of the thin slab strand and guide the progress of the strand.

The present invention will be described in detail below based on the drawings.

FIG. 1 shows the most realistic equipment configuration for continuous casting and hot rolling of thin slabs.

First, this diagram will be explained.

In the figure, 1 is a continuous casting device for thin slabs, 2 is a forced guide roll, 3 is a surface light reduction mill, 4 is an ethosier for medium change,
5 is a presser roll, and the surface light reduction mill 3 is an etching roller 4.
It also serves as a pinch roll and is a tension-applying type.

In addition, 6 is a thin slab, 7 is a heat retention furnace, 8 is a running cutting shear,
9 is a winding machine. Further, 10 is a Hasofa furnace for maintaining the thin slab 6 wound into a coil at a high temperature and uniformizing the temperature of the coil, 11 is a coil unwinding machine, 12 is an edge heater, and 13 is a finishing mill. 14 is a cooling zone, and 15 is a winder for winding the hot steel strip.

The processing system for the thin slab 6 in the above-mentioned hot steel strip production equipment is shown as an example of two strands in the continuous casting equipment.

Further, FIG. 2 schematically shows a belt caster provided in the thin slab continuous casting apparatus 1.

In the process of directly supplying the thin slab 6 obtained by continuous casting to the rolling process, a production system reducing device is essential.

In the equipment shown here, light surface reduction mills 3 are installed on the outlet and inlet sides of the evaporator 4, and the thin slab 6 is subjected to buckling under medium pressure while being subjected to appropriate tension under the reduction by the mill 3. It was configured to expand the limits and change the width.

The present invention is designed to prevent the progress of the slab strand by contacting the middle end of the thin slab 6 obtained from the continuous casting device 1 on the entry side, exit side, or both sides of the surface light reduction mill 3 in such manufacturing equipment. A side guide is provided to guide the movement.

FIG. 3 is an enlarged view of the main parts of the hot steel strip manufacturing equipment according to the present invention.

In the figure, 16 is a side guide on the front side of the surface light reduction mill 3, and 17 is a side guide on the rear side of the surface light reduction mill 3. Although not shown, these guides reciprocate in a direction perpendicular to the direction of movement of the thin slab 6. It is connected to a movable drive device, and has a mechanism that abuts both sides of the strand of the slab 6 to guide its progress.

Note that the medium reduction device for the thin slab 6 is placed on the rolling equipment side and is provided for each strand of the casting equipment, because before the running cutting shear 8, the slab being poured is connected seamlessly. This is because it is advantageous to apply medium pressure to the slab 6 except for its leading and trailing ends.

(Function) FIGS. 4(a) and 4(b) are diagrams schematically showing the solidification process of molten copper in the belt caster 1a provided in the continuous casting apparatus 1. As shown in the figure, the belt caster 1a is supported by the cooling water supplied from the water cooling pad 1g via a water film flow, while the slab 6 in the solidification process is supported by this belt. Therefore, thin slab 6
The cross-sectional shape of the thin slab 6 obtained by such a device 1 is determined by the water film, the flexible bell) If, and the pressure balance with the molten steel. However, there is. In other words, in extreme cases, the cross-sectional shape may become uneven (see Figure 4(b)).
. Further, this shape is not necessarily constant in the longitudinal direction of the thin slab 6, and tends to have a random cross-sectional shape in both the longitudinal direction and the width direction.

The thin slab 6 having such a shape is processed by a surface light reduction mill 3.
Alternatively, in the case of rolling with the hot rolling mill 13, the profile of the obtained product may become random, especially if the thickness deviation in the middle direction of the thin slab 6 is large.
Since the longitudinal elongation of the thin slab 6 due to rolling is not uniform across the width, large lateral bending occurs. As a result, there is a significant defect in the width accuracy of the product, and the occurrence of this lateral bending may cause the material to be rolled to meander, making rolling virtually impossible.

On this point, in the case of conventional hot rolling equipment, the slab obtained by continuous casting is first fed to the rough rolling mill, so the temperature non-uniformity of the slab and subtle changes in rough rolling can cause the slab to roll in the mid-direction, longitudinal direction, etc. Even if non-uniformity occurs in the direction, it will not change randomly like in the case of the thin slab targeted this time, so it will be possible to make a thorough prediction and feed bank control, and use rolling equipment that can perform single-rolling control, for example. Although we were able to deal with this problem, there are disadvantages as mentioned above when directly hot rolling a thin slab obtained by continuous casting, so it is necessary to correct the thickness deviation of the thin slab in advance before finishing rolling. There is.

In this invention, when continuously casting thin slabs and directly hot rolling them, on the inlet side or the outlet side of the surface light reduction mill 3 disposed downstream of the continuous thin slab casting apparatus 1, or on both sides thereof,
By providing the side guides, the progress of the thin slab 3 is guided, so that the occurrence of camber caused by deviations in the thickness of the slab can be reduced as much as possible.

Although FIG. 3 shows an example in which side guides 16 and 17 are provided on the inlet and outlet sides of the light reduction mill 3 on the inlet side of the evaporator 4, in a steady state, the camber due to the reduction of the evaporator 4 Although it is possible to omit the side guide 17 on the exit side of the light reduction mill 3 in hopes of suppressing the effect, it is possible to omit the side guide 17 on the outlet side of the light reduction mill 3, but this may prevent the occurrence of camber at the leading edge of the casting of the thin slab 6 or the occurrence of camber at the leading edge of the casting due to the reduction of the light reduction mill 3. In order to smoothly insert the thin slab 6 into the ethosher 4 without generating camber, it is desirable to install a side guide also on the exit side of the surface light reduction mill 3.

In addition, if the thickness deviation of the thin slab 6 is particularly large,
It is also possible to install a side guide on the inlet side, the outlet side, or both sides of the surface light reduction mill 3 located on the outlet side of the esoager 4, and in particular, the side guide can be used only for the light reduction mill 3 on the inlet side of the esoager 4. It is not limited to this.

(Effects of the Invention) According to the present invention, it is possible to reduce as much as possible the occurrence of galling caused by thickness deviation of thin slabs, which has been a problem in establishing continuous processes from continuous casting to hot rolling. It has become possible to easily prevent quality deterioration due to product dimensions.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing hot-worked steel strip production equipment, Fig. 2 is a perspective view of a heald caster equipped in a continuous casting device, and Fig. 3 is an enlarged view of the main parts of the hot-worked steel strip production equipment according to the present invention. , FIGS. 4(a) and 4(b) are diagrams illustrating the solidification process of molten steel within the belt caster.

Claims (1)

[Claims] 1. A hot steel strip production facility comprising a combination of a continuous casting facility for producing thin slabs and a rolling facility for directly hot rolling the obtained thin slabs, wherein said continuous casting facility A hot-worked steel strip, characterized in that a side guide is provided on at least one or both of the entry side or exit side of a surface light reduction mill disposed on the surface of the steel strip, the side guides coming into contact with both sides of the thin slab strand and guiding the progress of the strand. manufacturing equipment.