JPS61216802A - Width reduction method of hot slab - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The technical content described in this specification regarding the width reduction of a hot slab is to convey the hot slab based on the amount of thickness increment of the hot slab due to the width reduction. The present invention relates to a method and apparatus for adjusting the pass level of a roller to prevent warping of a hot slab.

In recent years, studies and improvements have been made to the manufacturing and rolling processes from the viewpoint of continuous and synchronized logistics and energy saving.In the field of hot rolling, high-temperature slabs produced by continuous casting are being processed directly or in high-temperature conditions. After charging into the heating furnace, it is rolled to ensure continuity.

A method for smoothly achieving continuity and synchronization from continuous casting to hot rolling is to integrate the casting width of the slab in continuous casting, or to create a slab before hot rolling that corresponds to the integration of the casting width. There is a width change.

(Prior art) Conventionally, a method for changing the width of hot slabs (hereinafter referred to as slabs), especially for significantly reducing the width, is the so-called VH method using sizing equipment that combines a vertical rolling mill and a horizontal rolling mill.
The sizing method was common, but a sizing technique was introduced as a more effective method in which the slab is pressed down in the width direction over its entire length (Japanese Patent Application Laid-Open No. 10120-1983).
Publication No. 1).

By the way, it is known that when a slab is subjected to width reduction, the area covered by the reduction becomes non-uniform, resulting in a change in the cross-sectional shape of the slab and an increase in thickness. This thickness increment due to width reduction (hereinafter referred to as thickness increment) occurs almost equally on the top and bottom surfaces of the slab, but when sizing with conventional vertical rolling mills and horizontal rolling mills, due to capacity issues, the width reduction per bath is The amount is about 150
The thickness increment that occurs is only a small amount as it is as small as mm, but in sizing by press reduction, width reduction of hundreds of dimensions is performed at a time, so the amount of thickness increment also increases.

In conventional sizing equipment, the roller table on the slab output side is fixed, and when a large thickness increment like the one shown above occurs, the slab is pushed up from the roller table due to the thickness increment, causing warpage in the slab. This was a big problem.

(Problem to be Solved by the Invention) By adjusting the level of the slab conveying line according to the estimated amount of thickness increase that will occur in the slab due to width reduction,
It is an object of this invention to prevent slab warping.

° (Means for solving the problem) This invention provides a method for estimating the amount of thickness increment caused by the width reduction of the press from the amount of width reduction when a hot slab being conveyed is continuously reduced in width by a press. The pass line level on the conveyance rollers on at least one of the slab entry side and the slab exit side of the press is adjusted according to the estimated or measured thickness increase amount, and the hot slab on the conveyance rollers is actually measured. This is a method for reducing the width of a hot slab, which is characterized by preventing push-up due to thickness increments.

The apparatus used to carry out the above method includes a press that continuously reduces the width of the hot slab, and conveyor rollers that convey the hot slab at the input and exit sides of the press. The present invention is characterized in that the position of the conveyance roller on at least one of the entry side and the exit side can be adjusted.

Note that the above conveyance roller is a general term for pinch rollers and table rollers.

Now, with reference to FIG. 1, the method of this invention will be explained in conjunction with its apparatus.

In the figure, 1 is a press that rolls down the width of the slab 2, 3 is a table roller, and 4 is a table frame on the slab exit side, to which the pinch roller 11 and the table roller 3 are fixed. Furthermore, a pinch roller 12 and a table roller 5 are installed on the slab entrance side of the press 1. These pinch rollers 11 and 12 and table rollers 3 and 5 serve as transport rollers.

These conveyor rollers are operated intermittently in synchronization with the continuous rolling operation of the press, and sequentially move the slab to the rolling position of the anvil.

Further, one end of the table frame 4 is rotatably fixed to a support base 9, and the other end is fixed to the upper end of an adjustment screw 6 that moves up and down via a worm type transmission 7 driven by a motor 8. ! By vertically moving J and -6, the inclination of the table frame 4 is adjusted and the positions of the table roller 3 and the pinch roller 11 are adjusted.

The position adjustment of the table roller 3 and the pinch roller 11 can be easily determined from the relationship between the amount of width reduction to the slab and the amount of thickness increment that occurs, once the material slab and the amount of width reduction are determined. For example, in Figure 2, the dimension of the slab is 220 m.
This shows the relationship between the amount of width reduction and the amount of thickness increment that occurs in the case of m1l x 1500o++n width, and the positions of the table roller 3 and pinch roller 11 can be adjusted according to the amount of thickness increment relative to the amount of width reduction.

Further, as shown above, the amount of thickness increment may be recorded in relation to the amount of width reduction for each dimension of the material slab, but for example, the amount of thickness increment D=f(Δw, t, '1'.

It can also be expressed as a mathematical formula. Here, ΔW: width reduction amount, t: slab thickness, T: temperature.

More precisely, the thickness increment can also be determined by actually measuring the thickness using an optical means or a mechanical measuring means provided on the exit side of the press.

By the way, in the apparatus shown in Fig. 1, an example was shown in which the position of the table roller or pinch roller on the press exit side was adjusted, but all the table rollers up to the next horizontal rolling mill (first
The position of the table roller 13) in the figure may be adjusted. However, the inventors' experiments have shown that if the distance between the end (downstream side) of the table roller to be adjusted and the press is 173 or more of the slab length, the adjustment shown in Figure 1 is sufficient to prevent warpage. has been confirmed.

Further, although Fig. 1 shows an example of adjusting the position of the conveyance roller on the exit side of the press, the conveyance roller on the input side of the press may also be adjusted to increase its level according to the amount of width reduction. Even if both the side and entry side conveyance rollers are adjusted, this invention is compatible and sufficiently effective.

Further, in the apparatus shown in FIG. 1, the position of the conveyance roller is adjusted using a motor, a worm type transmission, and an adjustment screw, but a hydraulic cylinder or a link mechanism may also be used.

(Function) As shown in FIG. 3, when the width of the slab 2 is reduced by the press 1, the thickness of the slab 2 increases. And as shown in Figure 4,
When the slab 2 with the increased thickness is transported on a normal transport line, the slab 2 is warped due to the increased thickness.

In order to prevent this warping, an adjustment may be made to provide a head on the conveyance line on the exit side of the 10 presses depending on the amount of thickness increment.

Incidentally, the amount of thickness increment changes depending on the width reduction amount of the slab. For example, slab width integration in continuous casting is
+n+++ pitch, the width reduction of the slab is 30
It will vary within a range of h+m.

Therefore, as the width reduction amount increases, the thickness increment also increases, and the warpage of the slab also increases.

Therefore, by adjusting the pass level of the conveying roller according to the amount of thickness increment, it is possible to prevent the slab from warping.

(Example) When width-reducing a slab with a thickness of 220 mm and a width of 1500 mm, the amount of thickness increment is estimated from the relationship between the amount of width reduction and the amount of thickness increment shown in Fig. 2, and east transport is carried out based on this estimated amount. Figure 5 shows the amount of warpage of the slab obtained as a result of adjusting the position of the rollers.

Further, FIG. 5 also shows the amount of warpage when a slab of the above dimensions was subjected to a similar width reduction and transported in the conventional manner as shown in FIG. 4.

As is clear from the figure, in the conventional example, the amount of warpage increases as the amount of width reduction to the slab increases, but in the embodiment, the amount of warpage of the slab hardly depends on the amount of width reduction and is a minute value.

(Effects of the Invention) As explained above, according to the present invention, it is possible to minimize the occurrence of warpage due to width reduction of the slab, thereby greatly contributing to improved operability.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the continuous width reduction device, Fig. 2 is a graph showing the relationship between width reduction amount and thickness increment, Fig. 3 is an explanatory diagram showing the shape of the thickness increment, and Fig. 4 is based on the thickness increment. FIG. 5 is a graph showing the relationship between the amount of width reduction and the amount of warpage of the slab.

Claims (1)

[Claims] 1. When a hot slab being transported is subjected to continuous width reduction by a press, the amount of thickness increment caused by the width reduction of the press is estimated or actually measured from the amount of width reduction, and the slab of the press is The pass line level on at least one of the conveying rollers on the entry side and the exit side is adjusted according to the amount of the estimated or measured thickness increment, thereby preventing the hot slab from being pushed up by the thickness increment on the conveying roller. Width reduction method for hot slab. 2. Equipped with a press that continuously reduces the width of the hot slab, and conveyance rollers that convey the hot slab on the entry and exit sides of the press, and at least one of the entry and exit sides of the press. A continuous width rolling device for hot slabs, characterized in that the position of the conveying roller is adjustable.