UA73985C2 - Rolling mill for production of thin hot-rolled strip - Google Patents

Abstract

Invention relates to machine building, in particular - to the construction of rolling mill for production of thin hot-rolled strip. Rolling mill for production of thin hot-rolled strip, comprising heating furnace, transport and working roller conveyers, rough reversible cage, rolling device, flying cutting shears, finishing continuous rolling group, consisting of several stands, group of winders for winding of strip into the cylinder. The table is also equipped with additional reversible roughing stand mounted between roughing reversible stand and rolling device with formation of continuous reversible rolling group with said roughing stand, in this case, the distance from additional reversible roughing stand to the rolling device is selected from the condition, that it is determined by the length of strip obtained in the first roughing cut through the continuous roughing reversible rolling group according to the formula: , where L - distance between the additional reversible roughing stand and rolling device, L??????. - length of strip in the first roughing pass, Vn - speed of the motion of strip at rolling, a - slowing of movement at braking of the strip. Invention provides for improvement of the quality of thin hot-rolled strips.

Description

Description of the invention

The invention relates to metallurgical machine building, namely to semi-continuous hot rolling mills, which are installed in rolling shops of metallurgical plants for the production of thin hot-rolled slabs from slabs.

Known semi-continuous state | Rolled production. Textbook for universities, 3rd edition, P. I. Polukhin,

Fedosov N.M., Korolev A.A., Matveev Yu.M., M., Metallurgy, 1982, p. 381-391), which contains: - furnaces for heating slabs; - rolling cage with vertical rolls; - the first draft reversible rolling cage; - universal draft reversible four-roll rolling cage; - flying scissors; - continuous net rolling group, which consists of six rolling cages; - two winders for winding the finished hot staff.

Production of thin hot-rolled slabs is carried out in the following technological sequence: the slabs, after heating in the furnace, are sent to a cage with vertical rolls and the first draft reversible cage. In the process of rolling, the staff moves in a reversible mode along the roller conveyor and after the last rough pass in the first cage is placed in a rough four-roll cage for reversible rolling in it. The distance between the cages is chosen in such a way that the tackle of the maximum length is placed between them. After rolling in the rough group of cages and trimming the defective ends of the staffs on the flying shears of the staff, it is transferred on roller conveyors to the continuous finishing group of cages, where it is rolled to the final thickness and wound on winders into a roll.

The disadvantages of the described state are as follows: - large distances between draft cages for placing between them a pad of intermediate length; c - large distances between the draft cage and the finishing rolling group for placing the maximum roll (3 lengths after the last rough pass; - the above-mentioned disadvantages, i.e. large technological distances between the rolling cages, lead to additional heat consumption during transportation of the staffs, which significantly affects the quality, and growth of state dimensions, which increases its metal content

As a prototype, a semi-continuous condition was chosen according to the US patent Mo3803891, B2181/32. with

The state includes the following equipment: - furnaces for heating slabs; Me. - transport and working roller gangways; so - reversible draft cage; 3o - intermediate winding device; c - flying scissors; - continuous net rolling group consisting of six rolling cages; - a group of winders for winding the finished hot staff. "

The technology of rolling on this condition includes: From 70 - draft reversible rolling of staffs in a draft cage; c - folding staffs on the intermediate folding device during the last draft pass; with" - the next deployment of the headquarters, trimming of the ends with flying scissors and the task in a non-stop cleaning group of cages; - rolling in a continuous finishing group of cages to the final thickness; - winding of the finished staff on winders.

In this method of rolling, unlike the analogue, the reversible rough cage is as close as possible to the 7th finishing group of cages due to the installation of a rolling device in front of them. Therefore, the tailings in the last draft pass are not laid out along the entire length on the intermediate roller conveyor, but are folded into a roll, from which the head is fed into the finishing cages. ee, Disadvantages of the condition: o 20 - low productivity of the rough rolling stage due to the presence of one rough cage, which leads to an increase in the processing time of rolled products at this stage and additional cooling of the bars before finishing rolling, which further reduces the quality of the finished bars; - an increased distance between the draft cage and the rolling machine, necessary due to the technological conditions of rolling, i.e. to place the undercut received in the penultimate odd draft pass, 29 for example, after the 3rd pass with a total number of them equal to 5; or after the 5th pass, with the general

GF) their number is equal to 7. The increased distance leads to additional cooling of the staff during transportation along the roller conveyor between the draft cage and the rolling machine, which negatively affects its quality. The basis of the invention is the task of improving the quality of thin staffs.

This task is solved due to the technical result, which consists in reducing the heat loss of the intermediate 60 pad during rough rolling.

In order to achieve the above result, a condition including a heating furnace, transport and worker roller gangways, a draft reversible cage, a rolling device, flying shears, a finishing continuous rolling group consisting of several cages, a group of winders for winding the staffs into a roll, according to the invention is supplied an additional reversible draft cage, installed between the said draft bo reversible cage and the collapsing device, forming a continuous reversible rolling group with the said draft cage, while the distance from the additional reversible draft cage to the collapsing device is chosen on the condition that it is determined by the length of the staff obtained in to the first draft pass Through a continuous draft reversible rolling group according to the formula:

That's hip.

Female: where I is the distance between the additional reversible draft cage and the collapsing device;

Her gender - the length of the staff in the first draft pass;

Ma - the speed of the staff during rolling; and - deceleration when braking the movement of the headquarters.

As a result of the comparative analysis of the proposed solution with the prototype, it was established that they have the following common features: - heating furnace; - Draft reversible cage; - folding device; - flying shears; - net continuous rolling group consisting of several cages; - transport and working roller gangways; - a group of winders for winding staffs into a roll; as well as distinctive features: - additional reversible draft cage forming a continuous reversible rolling group with the first draft cage; - the distance from the additional reversible draft cage to the collapsing device is chosen on the condition that it is determined by the length of the staff obtained in the first draft pass through the continuous draft reversible C rolling group according to the formula:

I, for: where I is the distance between the additional reversible draft cage and the collapsing device;

Her gender - the length of the staff in the first draft pass; i am

Ma - speed of movement of the staff during rolling; so a - deceleration of movement when braking staffs.

Thus, the proposed rolling mill has new component parts, a new form of execution of these parts, and a new arrangement of component parts relative to each other. co

There is a cause-and-effect relationship between distinctive features and the technical result achieved.

Due to the fact that the rolling mill is supplied with an additional reversible draft cage, which forms a non-stop - reversible rolling group with the first draft cage, it became possible to carry out rough rolling along Z draft passes through two cages, which reduces time and increases the productivity of rough rolling.

In addition, in the proposed state, it became possible to reduce by approximately 1.5 times the distance from the additional "reversible draft cage to the collapsing device, because the length of the undercut after the first rough pass through two cages is 1.5 times shorter than the length of the undercut on the prototype, determined by the third by passing through the Z s draft cage (in the rolling technology according to the prototype - 5 draft reversal passes). » Due to the increase in the productivity of rough rolling, the time of its implementation was reduced, which reduced the heat loss of the intermediate roll in this operation, as well as the heat loss of the roll when transporting it on intermediate roller gangways between the rough group and the rolling machine was reduced, because their length was significantly reduced in comparison with a prototype. Reducing the heat loss of the rolling stock at the above-described stages of its processing led to - an increase in the quality of the finished stock. 2) The exclusion of at least one from the above set of distinguishing features does not ensure the achievement of a technical result. se) The claimed technical solution is not known from the prior art, therefore it is new. o 50 The claimed technical solution has an inventive level, therefore the proposed construction of a state for the production of thin hot-rolled staff for specialists does not follow from the state of the art. sl The proposed technical solution is practically applied, because its technological and technical implementation does not present any difficulties.

According to this decision, a sketch project of the state of 1500 for the Novolipetsk metallurgical plant was completed.

Thus, the proposed decision can be given legal protection because it is new,

GF) has an inventive level and is industrially applied, that is, it meets all the criteria of the invention.

The claimed technical solution is explained by a drawing showing the location of the equipment in a semi-continuous state, side view.

The machine for the production of thin hot-rolled bars consists of a heating furnace (not shown in the drawing 60), transport and working roller conveyors 1, a draft continuous rolling group consisting of two cages 2 and 3, a wrapping device 4, located at a distance Y behind the additional draft cage 3, flying shears 5, finishing continuous rolling group b, which consists of 6b cages. The rolling mill also contains a group of winders for winding the hot stock into rolls (not shown in the drawing). Distance |. between the draft reversing cage C and the rolling machine 4 is determined taking into account the placement of the staffs between them in the first draft pass through the cages 2, C and the section of the roller conveyor, on which the staff slows down from the rolling speed to a complete stop before reversing. In an analytical form, this distance is expressed by the formula: I "and

E-dvdk t, where I is the distance between the additional reversible draft cage and the collapsing device;

Her gender - the length of the staff in the first draft pass;

Ma - the speed of the staff during rolling; and - deceleration of movement when braking staffs.

The rolling mill works as follows.

After heating in the furnace, the blank is fed through roller conveyors 1 for reversible rolling to the rough reversible rolling group and in the first pass is passed through cages 2, 3. Rolling is carried out simultaneously in two cages and after the first pass of the staff is placed between cage C and the rolling device 4 on the intermediate roller conveyor . The length of the roll after the first pass determines the distance Y by which the rolling machine 4 stands back 75 from the rolling cage 3. After the second reversible pass through the cages 3, 2 staffs are laid out on the roller conveyor between the first draft cage and the furnace.

In the third rough pass, the staff is passed through the cages 2, C and simultaneously rolled into an intermediate roll in the wrapping device 4. After the winding is finished, the roll is unrolled (at the same time, the rear end of the staff becomes the front), the defective ends of the staff are cut off with flying scissors 5, and the staff is set for rolling in the final continuous group of cages 6 for rolling to the final thickness and wound into a roll on the coilers of the hot staff.

The advantages of the proposed solution in comparison with the prototype are that, thanks to the installation of an additional draft cage, the productivity of the rough rolling stage increases, the distance between the initial draft cage and the rolling machine decreases. All of this in combination leads to a reduction in the time of rolling and the transportation of staffs, a reduction in losses of rolling temperature and an improvement in the quality of finished products. at

Claims (1)

Formulation of the invention IF) A rolling mill for the production of thin hot-rolled bars, containing a heating furnace, transport and co-working roller gangways, a draft reversible cage, a coiling device, flying shears, a clean continuous rolling group consisting of several cages, a group of winders for winding the bars in a roll, Ge"! which is distinguished by the fact that it is equipped with an additional reversible draft cage installed between the mentioned reversible draft cage and the collapsing device with the formation of a continuous reversible rolling group with the mentioned draft cage, while the distance from the additional reversible draft cage to O /-|cha of the collapsing device is selected by provided that it is determined by the length of the staff obtained in the first draft pass through a continuous draft reversible rolling group according to the formula: гра" И, -и зх е " - шля. ! - s where ГИ - the distance between the additional reversible draft cage and the collapsing device, I dol is the length of the staff in the first draft pass, Mi is the speed of movement of the staff during rolling, and is the deceleration of movement during "" braking of the staff. -and (95) se) (ee) sl name) 60 b5