JPH01178302A - System for hot rolling - Google Patents

Abstract

PURPOSE:To prolong a service life of a finishing rolling roll by installing a bender for crown control at the outlet of a thin sheet continuous casting machine and a finishing tandem rolling mill in the downstream side of the machine, respectively. CONSTITUTION:A bender 4 controlling crows is installed at the outlet of a thin sheet continuous casting machine 3 consisting of a tundish 2, mold, and may pinch rolls 8, etc., and a cutter 5 and a finishing tandem rolling mill 6 are successively installed. A thin sheet slab 9 delivered from the outlet of the mill 3 enters the bender 4 and is subjected to crown control in accordance with wear of rolling rolls of a finishing mill 6. That is, a sectional shape of the slab 9 is corrected by the bender 4 in accordance with wear amounts and wear positions of finishing rolls. Thus, a service life of the finishing rolls is prolonged because progress of wear of the rolls is restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) This invention relates to a hot rolling system for manufacturing metal strips.

(Prior Art) In a hot strip steel rolling system that includes a continuous casting machine and a finishing tandem rolling mill that can continuously obtain a thin plate having a thickness of approximately 30 to 5 Qml at the exit, the service life of the rolls has been limited. A finishing tandem rolling mill is equipped with a bender for the purpose of enlarging the area and improving the cross-sectional shape of the plate, and the shape of the work roll is narrow in the center and open on both sides to control the cross-sectional crown of the plate.

This is because roll wear is unavoidable when rolling metal with rolls, and if rolling is continued with rolls that are particularly worn in the center, the cross-sectional shape of the rolled plate A will be as shown in Figure 2. This is because, as shown in the figure, the crown shape reflects the wear of the rolls and the deflection of the rolls, so it is necessary to control this crown and produce a plate with a cross-sectional shape as flat as possible.

In equipment such as a bender for controlling the cross-sectional shape, the bender of the finishing tandem rolling mill is operated in consideration of the degree of roll wear caused by rolling, the location of the wear, and the roll deflection caused by rolling, so that a flat plate material can be obtained. I have to.

However, if the rolls become excessively worn, the rolls will have to be replaced because the bender will exceed its ability to control the shape of the finished plate material. Therefore, there has been a great need to extend the life of the rolls as much as possible.

Therefore, if the cross-sectional shape of the thin plate slab entering the finishing tandem rolling mill is prepared in advance, the burden of cross-sectional crown control by the bender equipment in the finishing tandem rolling mill will be reduced, and the roll wear value can be reduced accordingly. It is thought that it can extend the lifespan.

On the other hand, the hot rolling system that directly connects a continuous thin plate casting machine to a finishing tandem rolling mill is a technology that has been developed very recently, and until then, thick plate slabs with a thickness of approximately 150 to 2501 mm at the exit were cast. A rough rolling mill was installed between the continuous sheet casting machine and the finishing tandem rolling mill, and the rough rolling mill rolled the sheet into a thin plate, which was then connected to the finishing tandem rolling mill.

In such conventional rolling systems, even if a bender is installed at the outlet of the continuous casting machine to control the cross-sectional crown of the slab, the slab is significantly rolled down by the rough rolling mill downstream of the bender, so the bender There is no point in providing this, and the life of the rolls used in finishing tandem rolling cannot be extended.

(Problems to be Solved by the Invention) As described above, the conventional hot rolling system has a problem in that it is not possible to extend the life of the rolls of a finishing tandem rolling mill.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a hot rolling system that can extend the life of the roll portion of a finishing tandem rolling mill.

[Structure of the Invention] (Means for Solving the Problems) The hot rolling system of the present invention includes a thin plate slab crown control bender provided at the exit position of a continuous thin plate casting machine, and a thin plate slab crown control bender downstream of the crown control bender. The mill is equipped with a finishing tandem rolling mill.

(Function) In the hot rolling system of the present invention, the slab on the exit side of a conventional rough rolling mill is continuously cast by a thin plate continuous casting machine to a thickness of about 30 to 50 mm, and the thin plate slab coming out from the continuous thin plate forming machine R is On the other hand, crown control is performed by passing the strip through a bender, and after the cross-sectional shape has been adjusted, the thin plate slab is passed through a finishing tandem rolling mill to obtain a final strip by hot rolling.

(Example) Hereinafter, embodiments of the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which molten ferrous metal is contained.
A thin plate continuous casting machine 3 that continuously casts the lagoon supplied from the turn plate 2 to produce 1q of thin plate slabs with a thickness of about 30 to 50 mm, From the bender 4 installed at the exit of the continuous VL machine 3, the cutter 5 that cuts the thin plate slab to an appropriate length, the finishing tandem rolling machine 6 installed downstream of the cutter 5, and the finishing tandem rolling machine 6. The winding layer 7 winds up the finished steel strip.

Continuous thin plate casting! 13 is a large number of pinch rolls 8°8,・
Thin plate slabs 9 are continuously cast by .

The bender 4 forms the cross-sectional shape of the thin plate slab 9 sent out from the outlet of the continuous casting machine 3 so that the cross-sectional shape is flat.

Finishing tandem rolling type 6 is a process in which a steel strip 10 having a thickness of approximately 2 to 5 mm is continuously rolled and finished to a thin plate slab 9 having a thickness of approximately 30 to 50 mm.

The operation of the hot rolling system having the above configuration will be described next.

First of all, molten steel (lagoon) is put into dollar 1, and after passing through turn plate 2, the lagoon is cooled and there is no pinch.
-A group 8,8. ... is pulled out by the continuous casting machine 3, and the cutter 5 installed at the outlet of the continuous casting machine 3 cuts the cutter every fixed length.
and sent to the finishing tandem rolling mill 6. After being finish rolled by this finishing tandem rolling method 6, it is wound up by a winder 7, and the main rolling process is completed.

Here, the rolling rolls of the finishing tandem rolling mill 6 are worn mainly at the center of the roll, but if rolled as is, the plate A with a crown-shaped cross section as shown in FIG.
Since the roll is to be rolled, the crown control function of the bender equipment or the like provided in the finishing roll group is activated to form the cross-sectional shape.

At the same time, in order to reduce the burden on the crown control function of the bender equipment of the finishing tandem rolling mill 6, the shape of the thin plate slab 9 is controlled in advance by the bender 4 provided at the outlet of the R& continuous casting f113.

In other words, by operating this bender 4, the cross-sectional shape of the thin plate slab 9 is controlled to be optimal considering the amount of roll wear on the finishing tandem rolling R6 side and its location, and the thin plate slab 9 is sent to the finishing tandem rolling mill 6 side. be.

For example, if the roll wear area of the finishing tandem rolling mill 6 becomes large, the cross-sectional shape of the thin plate slab 9 is controlled by the bender 4 so that the cross-sectional shape is greatly concave in the center, and after passing through the finishing tandem rolling mill 6. On the contrary, when the wear amount of the roll group of the finishing tandem rolling mill 6 is small, the cross-sectional shape of the thin plate slab 9 is controlled by the bender 4 so that it has a substantially flat cross-sectional shape. That's what I do.

In this way, by controlling the shape of the thin plate slab 9 by the bender 4 in consideration of the progression of roll wear in the finishing tandem rolling mill 6 and the worn parts, the service life of the rolls on the finishing tandem rolling mill 6 side can be extended. It can be done.

[Effects of the Invention] As described above, according to the present invention, the bender is provided on the exit side of the continuous thin plate casting machine, and the finishing tandem rolling mill is provided downstream of this bender, so that the roll group of the finishing tandem rolling mill is The cross-sectional shape of the thin plate slab can be controlled by the bender by taking into account the degree of wear and the wear location of the finishing tandem rolling mill. Further rolling can be carried out even if the rolling distance is exceeded, and the life of the roll can be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a cross section of a slab. 1... Ladle 2... Turn date 3... Continuous thin plate casting machine 4... Bender 5... Cutter 6... Finishing tandem rolling machine 7... Winding machine 9... Thin plate Slab 10...Strip steel worker Konoji's plater Norichika Sosuke

Claims (1)

[Claims] A hot rolling system comprising a thin plate slab crown control bender provided at the outlet of a thin plate continuous casting machine, and a finishing tandem rolling mill provided downstream of the crown control bender.