JPS6219921B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a slab rolling method, and more particularly to a slab rolling method provided with means for preventing fish tails generated at the ends of the slab during width rolling.

Generally, in the next step, a slab manufactured by continuous casting or the like is reduced in width using a width rolling mill having vertical rolls, and then rolled to reduce its thickness using a horizontal rolling mill. However, in the case of this width rolling, as shown in Figure 1, the influence of the width reduction process by the vertical rolls 2 and 2' does not easily penetrate into the inside of the material, and the degree of restriction of processing deformation is small at the ends of the slab. Indentations A are created at the leading and trailing ends of 1. This hollow part is called a fishtail, and its amount is the maximum depth l.
It is expressed as _T and _lB. The fishtail part becomes industrially unusable and must be discarded, which causes a decrease in product yield.

Recently, as a means to prevent this fish tail, after pressing the end part B of the slab 1 into a tapered shape so that the end part width of the slab 1 becomes smaller, as shown in FIG. Slab rolling equipment has been proposed that performs this and prevents fish tails that are generated during width rolling.

By the way, in this type of slab rolling equipment, the important issue is where to install the above-mentioned press processing machine, and the way of installation can greatly affect the rolling time, installation space, etc. found.

That is, generally speaking, due to the rolling time schedule, this press machine is placed near the heating furnace, and taper forming and width rolling operations are performed independently. However, in the above-mentioned type, a space is required before and after the press machine that can accommodate the length of the slab that is the workpiece.
Providing such extra space in the hot rolling equipment line requires not only the equipment but also the building and site to be considerably large-scale, and also has the drawback of causing a drop in the temperature of the slab.

The purpose of the present invention is to reduce the size of a hot rolling equipment line as a device for preventing the generation of fish tails generated in width rolling, and to prevent the temperature of the slab from decreasing to enable efficient width rolling of slabs. The object of the present invention is to provide a slab rolling method that makes it possible.

The gist of the present invention is that a press device that width-reduces the front and rear ends of the slab along the traveling direction of the slab coming out of the heating furnace, and a vertical rolling mill that rolls the slab in the width direction are installed in close proximity to each other. With the rolls of the vertical rolling mill open, both the front and rear ends of the slab led from the heating furnace are subjected to width reduction forming using the press device, and then this slab is placed at the rear end position. The slab is advanced through the roll device of the vertical rolling mill to a position on the opposite side of the press device, and then the first rolling of the slab in the width direction by the roll device of the vertical rolling mill is carried out by the press device. The slab rolling method is characterized in that rolling is carried out in passes in exactly the opposite direction so as to proceed from the rear end to the front end of the slab with the press opened.

In other words, in the present invention, both the front end and the rear end of the slab led from the heating furnace are pre-formed by a press device, but in this case, the width reduction molding of the slab by the press device is performed in a vertical shape. Compared to the case where the width of the slab is reduced using only the rolls of the rolling mill, the width of the slab can be reduced, so the effect of width reduction extends to the center of the width of the slab, making it difficult for fish tails to occur. Become. Furthermore, after the front and rear ends of the slab are subjected to width reduction preforming using the press device to suppress the occurrence of fish tails, the area from the rear end to the front end is subjected to rolls of a vertical rolling mill along the longitudinal direction of the slab. Since width reduction rolling is performed, the front and rear ends of the slab, where fish tails are likely to occur, can be reduced in width by the rolls of the vertical rolling mill, and fish tails occur when the slab is width reduced. Therefore, the above-mentioned purpose can be achieved.

FIG. 3 shows an embodiment of the slab rolling equipment according to the present invention.
is arranged between the heating furnace 3 and the width rolling mill 8, and the press working machine 7 is arranged close to the width rolling mill 8. The press machine 7 has a pair of press tools 1 that perform taper forming on the front and rear ends of the slab 1.
4,14'. The shape of the press tools 14, 14' includes a substantially symmetrical inclined part that is inclined with respect to the center line of the plate width so that taper forming can be performed on both the leading end and the rear end of the slab 1, and a sloped part that is approximately symmetrical with respect to the center line of the plate width. It has a parallel part parallel to the plate width center line located between the inclined parts. This press tool 14,1
4' are detachably attached to the tips of pistons 16, 16', respectively, and the pistons 16, 16' are housed in cylinders 15, 15' supported by a frame 17 and reciprocate in the plate width direction. The width rolling mill 8 has a pair of rolls 18, 18' for rolling the slab 5 tapered at its front and rear ends. The rolls 18, 18' are supported by jocks 19, 19', and reciprocate in the width direction within the frame 22 by screws 21, 21' provided on the jacks 20, 20'.

The slab 1 extruded from the heating furnace 3 and conveyed in the direction of the arrow a by the table 4 is first introduced into the press machine 7 with its tip and stopped at the position shown by the solid line, and the tip is inserted into the press tool of the press machine 7. 14,1
4' is tapered by a predetermined amount. Thereafter, the press tools 14, 14' are separated and the slab 1 is further moved in the direction of arrow a to the state of the slab 5 shown by the dashed line.
4 and 14', the rear end is tapered. Next, the press tools 14, 14' are opened and the slab 5 is pulled out in a direction in which it is removed from the position of the rolls 18, 18' of the width rolling mill 8 in the minimum amount of time. Usually, it is preferable to pull it out in the direction of arrow a. The reason for this is that while the total length of the slab is around 10 m, the distance between the centers of the press machine 7 and the width rolling mill 8 is around 2 m, so it takes less time to pull it out in the direction of arrow a.

Thereafter, the rolls 18 and 18' of the width rolling mill 8 are set to a predetermined rolling position, and the slab 5 whose front and rear ends are tapered is conveyed backward in the direction of arrow b to perform a predetermined width reduction. Normally, width rolling requires reversible rolling of about two passes, so the slab is conveyed in the direction of arrow b in the first pass and in the direction of arrow a in the second pass, and width rolling is performed over the entire length. Thereafter, the slab is conveyed by the table 6 in the direction of arrow a and subjected to a predetermined rolling process in a horizontal rolling mill 23. By setting such a path schedule, it is possible to eliminate wasted time due to empty paths and the like. In addition, horizontal rolling mill 2
3 is installed for the purpose of reducing the thickness of the slab, and usually consists of two or four stages of rolls.

As explained above, according to the present invention, it is possible to significantly improve the rolling yield by preventing the dead tail generated in width rolling, and also to downsize the hot rolling equipment that performs this width rolling. This has the effect of preventing temperature drop and realizing efficient width rolling.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the formation of fish tails during width rolling, Fig. 2 is an explanatory diagram of the width rolling method in which the plate ends are formed into a tapered shape, and Fig. 3 is a layout diagram of the slab rolling equipment according to the present invention. It is. 1, 5... Slab, 3... Heating furnace, 7... Press processing machine, 8... Width rolling mill, 23... Horizontal rolling mill.

Claims (1)

[Claims] 1. In a press device that width-reduces the front and rear ends of the slab along the traveling direction of the slab coming out of the heating furnace, and a vertical rolling mill that rolls the slab in the width direction, which are arranged close to each other, the vertical rolling mill With the rolls of the mold rolling mill open, both the front and rear ends of the slab guided from the heating furnace are subjected to width reduction forming using the press device, and then this slab is passed through the roll device of the vertical rolling mill, with the rear end position of the slab being reduced in width. The first rolling of the slab in the width direction on the roll device of the vertical rolling mill is carried out with the press of the press device being opened. A slab rolling method characterized by rolling in exactly the opposite direction passes so that the slab rolls from the rear end to the front end.