KR20110071135A - Method and device for descaling a metal strip - Google Patents

Abstract

The present invention relates to a method for producing a flat product of a steel material from thin strands which are subjected to upsetting and subsequently through roughing and finishing rolling trains, or from continuous casting slabs having a very thick or medium thickness. The manufacturing method is characterized in that the product is descaled at its strip edge prior to the upsetting process. The production method of the present application is carried out in a rolling sequence including at least one first upsetting device 1, rough rolling sequence, and finishing rolling sequence. The rolling train is characterized in that a first descaling device 2 is arranged in front of the first upsetting device 1 for descaling at the strip edge of the flat product.

Description

METHOD AND DEVICE FOR DESCALING A METAL STRIP}

The present invention relates to a flat product of steel material from thin strands which are upset and subsequently passed through a roughing and finishing train, or from a continuous cast slab with a very thick or medium thickness. It relates to a method for producing the.

Through the process for manufacturing flat products of steel or other metal materials, thin strands or very thick or medium width continuous cast slabs transfer and reverse single or multi-stand rough rolling, flat products. Is processed in the roller table. The method cools the flat product through an induction heating device for heating the crude rolling strip to a predetermined temperature over a crude rolling strip length and its width over a roller table section with tiltable thermal insulation lids. It is carried out not only in a multi-stand finishing mill comprising an outflow roller table with units for the purpose, but also in a winder arranged rearward to wind the final strip.

From EP 1 305 122 B1, a thin slab of carbon steel, alloy cemented steel or alloyed steel is subjected to two stages in which a pause process for intermediate cooling takes place through reversal on a roller table. It is known to allow rolling into one or more rough rolling strips. The rough rolling strip is heated to a predetermined temperature over length and width through the combined action of the lids and the heating unit and rolled into a thin, high strength final strip in the two phase region (austenite-ferrite) in a multi-stand finishing mill. , By the rolling temperature located in the upper austenite region as the rolling temperature of the first forming step in the rough rolling heat, when the total shrinkage ratio is 40 to 70%, the continuous casting structure is converted into the rolling structure through complete recrystallization. . The conversion start temperature converted to the two phase region is increased by the particulate and partially solidified structure so as to reduce the molding resistance which shortens the conversion time. Depending on the thickness and layer of the rough roll strip, the thickness of the final strip, the rate of entry into the finish rolling sequence, and the cooling action of the descaler in front of the finish rolling sequence, the rough rolling strip has closed caps over its length and width. And through the combined action of the induction heating unit, the rolling process is carried out in a two-phase region in every pass in the finishing rolling train to be uniformly adjusted to the desired temperature. The descaler is mounted to the rear of the roughing mill in the rolling direction and just before the finishing mill, and serves to remove the scale from the surface of the slab, not the edge of the slab.

From JP 07 047 419 A a hot rolling method is known, in front of the rough rolling stand, which is provided with an upsetting device for the side upsetting treatment of the rolling strip. In this case a descaling device is provided between the upsetting device and the rough rolling stand, by which the continuous casting slab is descaled by a jet of water on its surface. The two side upsetting rolls in the upsetting apparatus are therefore equipped with shielding plates which must prevent the water of the descaling apparatus from cooling the side strips sideways. The shields are mounted on the side guides, whereby the spacing of the shields relative to the rolling strip also changes when the strip width is changed.

It is an object of the present invention to provide such a method which is improved over methods known from the prior art in a method for cleaning a metal strip during manufacture.

This object is achieved with respect to the first mentioned method according to the invention, in which the flat product is descaled at its strip edge prior to the upsetting process.

If the scale is not removed at the edge of the strip, there is a risk that the scale is pressed in during the upsetting process and therefore the quality of the rolling strip is degraded. The above disadvantages for strips rolled according to the prior art are thus solved by the present invention.

Advantageous refinement embodiments of the invention are taught from the dependent claims.

According to the present invention, it is preferably provided that the flat product is further descaled at its strip edge after passing the rough rolling sequence and before passing the finishing rolling sequence. The flat product can then also be further set up.

Preferably the flat article is descaled by a fluid, in particular at least one high pressure water jet, at high pressure at its strip edge.

In order to achieve optimal descaling, the at least one high pressure water jet is oriented towards the flat product at an angle of 60 ° to 90 °, particularly preferably at an angle of 75 ° with respect to the side surface of the flat product. When the descaling station is arranged in front of the rough rolling train, the water jets are preferably oriented towards the strip edge from three nozzles arranged up and down.

The invention also relates to a rolling sequence for producing flat products of steel from thin strands or from continuous cast slabs of very thick or medium thickness, including upsetting devices, rough rolling sequences and finishing mill sequences. It is about.

According to the invention, the rolling train is characterized in that, in front of the first upsetting device, a first descaling device for descaling at the strip edge of the flat product is arranged.

In addition, according to an improved embodiment, a second upsetting device is provided in front of the finishing rolling train, and in front of the second upsetting device is provided a second descaling device for descaling at the strip edge of the flat product.

According to a preferred embodiment of the rolling train, the first descaling device comprises a plurality of nozzles, in particular three nozzles, each facing at the strip edge at both strip edges of the flat product. The second descaling device comprises at least one nozzle from each of the strip edges to each of both strip edges of the flat product corresponding to the thickness of the strip thinner by the rolling process, from which the fluid, in particular water, In the state is radiated to the edge of the strip.

Preferably, in particular, the nozzles are mounted at the side guides in the direction of the upsetting device as end of the side guides, in the side guides of the rolling train, in particular in the straight guides of the side guides, With this, the width adjustment can be made, in particular with straight guides. The fixing of the nozzles to the side guides or straight guides is specifically directed to the strip edge, provided that the side guides or straight guides are always drawn out to the strip edge surface (which is always the case in practice). The spacing of the nozzles has the advantage that it is always constant / same. The constant spacing of the nozzles with respect to the strip edge preferably provides a constant amount of impact (impact) of the jet of water radiated from the nozzles to the strip edge, and thus a uniform descaling action.

Likewise preferably the nozzles respectively radiate fluid toward the strip edge of the flat product at an angle of 60 ° to 90 ° with respect to the side surface of the flat product, in particular at an angle of 75 °.

In the following the invention is described in more detail according to one embodiment.

1 is a cross-sectional view showing a rough rolled strip and a guide thereof located in a rolling sequence for producing a flat product of steel with a plan view of a descaling apparatus for removing the scale from the side edge of the flat product.
FIG. 2 is a side view partially showing the rolling train according to FIG. 1 in the front region of the upsetting stand. FIG.

For example, a rolling train placed behind the casting machine to produce a continuous cast slab with a very thick or medium thickness heats a shear for separating the cast strand into slabs, and a continuous casting slab introduced at low or high temperature. Or a heating or compensating furnace for adjusting the thin strands to the rolling start temperature, and in front of the upsetting device 1 (FIG. 2) for side upsetting the flat product. A descaling device 2 (FIGS. 1, 2) for descaling at the side strip edge of the product, wherein the upsetting device 1 itself is arranged in front of the roughing row.

Flat products or strips are conveyed through the rollers 3. The flat products are guided by straight guides 4 and 5 at their both longitudinal edges, where the straight guides extend in various positions along the width of each of the flat products. Therefore, for this purpose, the two straight guides 4 and 5 should be arranged symmetrically about the center and displaceable in the direction of the two-way arrow A transverse to the rolling direction of the flat products.

At the front ends facing the upsetting device 1 as the ends of the straight guides 4, 5, three spray nozzles 6a, 6b, 6c for injecting a high pressure water jet to the strip edge of the rolling strip; , 7b and 7c are disposed respectively. Water nozzles are spun from each of the nozzles 6a, 6b, 6c; 7a, 7b, 7c, overlapping the water jets so that the scale can be removed while completely pressing the side edges of the flat products.

With regard to the conveying area of the rolling strip, in addition, the injection walls 8 which are preferably fixedly mounted as spray protection on both sides outside the position of the nozzles 6a, 6b, 6c; 7a, 7b, 7c. , 9) are provided respectively. Thus each flexible medium supply chain 10, 11, each comprising a high pressure hose 12, 13 for supplying water from a common supply line 14 therein, is provided with a spray wall 8, 9. Each passes through and extends. If the positions of the nozzles 6a, 6b, 6c; 7a, 7b, 7c change in correspondence with the width of the rolling strip, the medium supply chains 10, 11 and the corresponding hoses 12, 13 are also displaced. .

The nozzles 6a, 6b, 6c; 7a, 7b, 7c are respectively integrated into the injection bars 15, 17 forming the mechanical rigid end pieces of the hoses 12, 13 on both sides. The injection bars 15, 16 are fixed to the straight guides 4, 5 and can be conveyed with the straight guides. By doing so, a constant action of the water jet on the side edges of the rolling strip is ensured, so that the scale can be removed from the side edges of the rolling strip, so that the scale is in the upsetting device 1 It is not press-fitted together, thereby improving the quality of the rolled strip.

1: upsetting device
2: descaling unit
3: roller
4: straight guide
5: straight guide
6a: nozzle
6b: nozzle
6c: nozzle
7a: nozzle
7b: nozzle
7c: nozzle
8: spraying wall
9: spraying wall
10: media supply chain
11: medium supply chain
12: hose
13: hose
14: supply line
15: spraying bar
16: spraying bar
A: two way arrow

Claims (9)

A method for producing a flat product of steel material from thin strands which are upset and subsequently passed through roughing and finishing rolling trains, or from continuous casting slabs of very thick or medium thickness,
Wherein said flat product is descaled at its strip edge prior to the upsetting process. 2. A method according to claim 1, wherein the flat product is further descaled at its own strip edge after passing the rough rolling sequence and before passing the finishing rolling sequence. Method according to claim 1 or 2, characterized in that the flat product is descaled by a high pressure fluid, in particular at least one high pressure water jet, at its strip edge. The flat product according to claim 1, wherein the at least one high pressure water jet is directed to the flat product at an angle of 60 ° to 90 °, in particular at an angle of 75 ° with respect to the side surface of the flat product. A manufacturing method characterized in that the spinning. The first upsetting device 1, the rough rolling sequence and the finishing rolling sequence, from a thin strand or from a continuous cast slab with a very thick or medium thickness to a rolling sequence for producing a steel plate product. In
In front of said first upsetting device (1) a first descaling device (2) arranged for descaling at the strip edge of said flat product. 6. A device according to claim 5, wherein a second upsetting device is provided in front of the finishing rolling train, and in front of the second upsetting device, a second descaling device for descaling at the strip edge of the flat product. Rolling mill heat. The device according to claim 5 or 6, wherein the first descaling device (2) comprises a plurality of nozzles, in particular three nozzles 6a, 6b, 6c; 7b, 7c), wherein the second descaling device comprises at least one nozzle from each of the strip edges to each of both strip edges of the flat product, from which the fluid, in particular water, is at high pressure. Rolling columns, characterized in that that can be radiated to the strip edge. 8. The nozzles according to claim 5, wherein the nozzles 6a, 6b, 6c; 7a, 7b, 7c are arranged in the side guides of the rolling sequence, in particular in the straight guides 4, of the side guides. 9. In 5) it is mounted as end of the side guides towards the upsetting device 1, whereby a width adjustment is made with the side guides, in particular with the straight guides 4, 5. Rolling mill characterized in that it can. The fluid according to claim 8, wherein the fluid is from said nozzles 6a, 6b, 6c; 7a, 7b, 7c at an angle of 60 ° to 90 °, in particular at an angle of 75 ° with respect to the side surface of the flat product, respectively. A rolling mill, which can be spun onto a flat product.

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