SU588697A1 - Continuous ingot mill - Google Patents

Description

(54) MILLING FOR CONTINUOUS INGOT

The invention relates to metallurgy, to equipment for joint continuous casting and rolling of metals, mainly for rolling continuous ingot, the movement of which alternates with stops.

Known rolling mills, designed for the combined rolling of continuous ingot. Such mills include multicell continuous mills, manic and planetary mills.

These mills for the combined rolling of continuous ingot are widely used, provided that the ingot from the mold is drawn continuously. If rolling of a continuous ingot is necessary, the movement of which alternates with stops, then the application of the known becomes practically impractical. In this case, the power of the mill increases dramatically, and its utilization ratio turns out to be small (only 10-30%).

A rolling mill is known, primarily intended for rolling an ingot, the movement of which alternates with stops. The mill contains a rolling mill stand with profiled rolls; a predominantly hydraulic drive for rolling mill rolls located on a movable rolling stand; drive the reciprocating movement of the rolling mill stand; a platform with guides mounted on it along which the movable rolling stand moves.

Rolling a continuous ingot in a known mill is carried out with a reciprocating movement of the rolling mill stand with its displacement towards the non-rolled portion of the continuous ingot after each stroke until the sum of such displacements is equal to the length of the ingot drawn from the crystallizer during the drawing period. Then, the movable rolling stand is moved to the side of the rolled part of the ingot for a distance equal to the specified amount of displacements, and after the next extrusion of the ingot from the crystallizer, the rolling is continued.

This mill allows for the efficient rolling of a continuous ingot, the movement of which alternates with stops.

with relatively little rolling effort. This to some extent limits the mill's productivity. If the mill drive capacity and, consequently, the rolling force are increased, the capacity of the mill increases, but then there are difficulties in expanding the more powerful drive on the stands of the rolling mill stand. The mill also does not reduce the rolling forces and cannot operate without an additional drive for idling the moving rolling stand.

The purpose of the invention is to create a mill, in which, with a roll mill drive power similar to that of a known mill, it is possible to create a rolling force greater than that of a known mill, and with increased rolling force, reduce the strain resistance of the rolled ingot due to additional heating of the rolled ingot part and creating nat in the deformation zone, which ultimately allows a significant increase in the reduction of the continuous ingot for each work movement of the rolling mill stand; eliminating a separate drive for idling movement of the rolling mill stand; reduction of formation (including due to additional heating) of oxides on the surface of the continuous ingot in its rolling zone and in the areas adjacent to the rolling zone; performing special operations on the mill, such as partial or continuous melting of the surface of the non-rolled part of the ingot, simultaneous rolling with thermofilling of a defective place on a continuous ingot. This is achieved by the fact that the rolling mill stand is mainly equipped with two pairs of inductors, which are installed above and below the rolled ingot between the stands and fixed with their bodies on the lower traverse of the rolling mill stand on both sides of the rolls.

Using inductors in a rolled ingot, induction currents induce heating of the ingot and create electromagnetic forces in the ingot, the reaction of which transmits pushing forces to the moving rolling stand through the inductors case, which provides a significant reduction in the drive power of the rolling rolls, and also the possibility of idle movements of the rolling mill stand.

The removal of defective places in the mill is achieved by the fact that, at the rolling mill stand, the inductors from the non-rolled part of the ingot are made of two independent pairs, each pair of inductors having an independent power source, one of which is high-frequency, and also In the case of an extreme pair of inductors, a device is installed for treating a defective place on the ingot surface by mechanical means, for example, by thermoforming.

FIG. 1 shows the proposed rolling mill; in fig. 2 is the same, section A-A in FIG. one.

The mill has two guides 1, installed on the foundation parallel to the rolling axis. The movable rolling stand 2 is located on the platform 3, which is provided with two pairs of rollers 4. Through these rollers, the weight of the movable rolling stand and the platform is transferred to the guides 1.

5Moving roll stand 2 has two

beds 5 fixed on the lower cross bar 6. On top of the bed they are connected by an upper cross bar 7. Pillows of profiled rolls 8 are permanently installed in the openings. Necks of profiled rolls are in the bearings of the pillows. The tail of the two pairs of necks of the rollers protrude beyond the pads. On one side, the roll necks are connected to hydraulic motors 9, the shells of which are mounted on Stable 5 Ninah 5, and on the other hand, gear gears 10 that are in engagement with each other are mounted on the cheeks. The gears are closed by covers.

On the lower traverse of the mobile cage 2

0, on each side of the rolls 8 between pairs of stands or close to the stands, pairs of preferably flat inductors 11-13 are installed, between which longitudinal bars 14 are placed along the edges. Distance between inductors 11, 12 and bars 14 corresponds to the size of the non-rolled part of the continuous ingot and the distance between the bars and inductors is 13 to the size of the rolled ingot, taking into account the necessary clearance between the inductors and

bars and rolled ingot.

On the side of the non-rolled part of the ingot there are two pairs of inductors 11 and 12. The need for their separate implementation is caused by the fact that power is supplied to them from different sources. An alternating current of higher frequency is supplied to one of the pairs of inductors, which allows heating the metal of the surface layer of the ingot in different ways and, if necessary, melting the surface layer. In order to facilitate the removal of molten metal from the ingot surface, inductors, to which high frequency current is supplied, in some cases it is advisable to install so that with their help the molten metal is removed to the side faces of the ingot. If there is no need to vary the heating of the surface layer of the ingot, instead of two pairs of inductors 11 and 12 on the mill can be

one pair of inductors is installed. On top of the inductors 12 and 13 are pressed transverse beams 15, which are attached to the uprights of the bed 5.; .

Brackets 16 and 17 with rollers 18 and 19 are attached to the extreme end walls of the inductors to support and guide the rolled ingot, and the rollers 18 and 19 are placed in such a way that the necessary gap between the rolled ingot and the inductors is provided in the process of feeding the continuous ingot to the rolling rolls and during the ingot rolling.

On the end wall of the inductors located on the side of the non-rolled part of the ingot, if necessary, instead of the roller 18, install a device for machining the surface of the ingot. Such a device can be, for example, two milling heads located above and below relative to the continuous ingot with the possibility of movement in the vertical plane (the upper milling head is indicated by the position 20).

Platform 3 houses high and low pressure collectors 21. The manifolds are connected through hydraulic lines to the rolling rolls and to the cooling systems of individual mill components, for example rolls, inductor windings, etc. Transfer case 22 is attached to the end walls of the platform 3, through which the power supply to the inductors is supplied. The power supply to the transfer boxes is supplied via a flexible power cable or through the current collectors 23 of the power supply 24 (the design of the current collectors and the power supply is determined depending on the operating conditions of the rolling mill). A closed cavity can be formed in the mill in the area of rolling rolls and inductors by installing sealing elements 25 and 26 above the inductors 12 and 13 along the upper crosshead 7, as well as installing devices 27 and 28 on the end walls of the inductors to close the gaps between the rolled ingot, inductors 12 and 13 and parallel bars 14.

In the upper yoke 7, two holes 29 are made, which can be blocked with plugs or connected to gas or liquid supply systems in a closed cavity 30. A container 31 mounted on the lower yoke 6 into which the lower mill roll is placed is in contact with the shells with one pair of side walls inductors 12 and 13, and another pair of walls with cutouts for the cheek rolls - with pillows rolls; it can be inserted, if necessary, into the closed cavity 30 together with the mill roll assemblies.

In the steady state rolling of a continuous ingot, the movement of which alternates with stops, the mill operates as follows.

After the next period of the ingot extrusion from the crystallizer, the movable rolling stand 2 is set to the position corresponding to the preset compression of the ingot for the subsequent working stroke. This installation of the rolling rolling stand is carried out with the profiled rolling rolls 8 withdrawn from contact with the rolled strip due to the pulling or pushing force generated from the reaction of electromagnetic forces induced in the rolled ingot through the inductors 12. Then the hydraulic drive of the rolling rolls is turned on, making an idle turn rolls at a small angle and clamps5 roll the rolled strip with rolling rolls. Simultaneously with the capture of the strip (ingot) by the rollers, inductor II -13 is connected to the operating mode of the moving rolling stand. The further working stroke of the rolling rolling stand is realized during rolling of the ingot by rolling rolls, whereby the rolling force is created both by driving the rolling rolls and by drawing a force through the inductors 11 and 12 and the pushing force through the inductor 13.

After the ingot is rolled by rolling rolls, the power supply to the inductors II and 13 is cut off; In this case, the rolls are separated from the rolled ingot and, after a small idle turn, are stopped in the extreme fixed position, and the inductors 12 move the movable rolling stand towards the non-rolled part of the ingot for a distance corresponding to the amount of ingot reduction during the subsequent

35 working movement of the rolling rolling stand in the direction of the non-rolled part of the ingot. Then, the mill rolls are reversed by hydraulic drive and at first they make a small idle turn, and then the ingot is grabbed by mill rolls.

0 rolls and begin his next compression. Simultaneously with the gripper of the ingot, the mill rolls, through inductors II and 12, create a pushing force on the movable rolling stand, and through inductors 13 -

5 t bore effort.

After the ingot is further reduced by the inductor 12, the movable rolling stand is again set in the position corresponding to the preset compression of the ingot during the operation of the movable rolling stand in the direction of

0 unrolled part of the ingot. Then everything is repeated until an ingot is rolled - a length equal to the length of the ingot drawn from the mold during the drawing cycle. After the ingot is reduced to the specified length, the movable stand with

5 inductors 12 and 13 are retracted to their initial extreme position in the direction of the rolled part of the ingot, and the rolling process is resumed after another ingot is drawn out of the crystallizer.

If it is necessary to prevent oxidation from being rolled by rolling my private ingot and the areas bordering on the rolling part of the ingot, rolling is carried out when fed to the closed section of 30 through the holes 29 of the non-oxidizing gaseous medium. At the same time, in order to reduce the flow rate of the gaseous medium through the gaps between the inductors, bars and ingot, devices 27 and 28 are put into operation, ensuring the prevention of leakage of the main part of the gas from the cavity 30 through the gaps indicated.

In the mill, the ingot can be rolled in a liquid protective medium supplied to the cavity 30. If the liquid medium is non-electrically conductive, leakage is prevented by devices 27 and 28, and if electrically conductive, leakage through the gaps between the inductors and the ingot is prevented by the electromagnetic inductors. In such a case, the ingot is rolled as follows.

When the movable stand moves in the direction of the non-rolled part of the ingot, its compression is carried out due to the tight force of the inductors 11 and 12 and the force from the hydraulic motor 9 of the rolls. The inductors 13 at this time create a slight pull of sufficient force to prevent the liquid phase from escaping through the gaps between the ingot, inductors, and the braids.

When moving the movable stand to the side of the rolled part of the ingot, compression is effected due to the pulling force of the inductors 13, pushing the force of the inductors II and the force from the drive of the mill rolls. The inductors 12 in this way create a small pulling force, sufficient to prevent liquid from flowing out through the gaps.

During idle movements of the movable rolling stand, inductors 12 and 13 create a pulling force on the movable rolling stand. Moreover, depending on the direction in which it is necessary to move the movable cage, the force may be different or of the same size, but the movable cage is then displaced by inductors II. In order to prevent the liquid medium from solidifying, especially during the initial rolling period, the liquid medium is heated in the vessel 31 in the lower mill roll zone.

The described mill can be used to remove some defects from the ingot surface. In this case, the ingot heating mode does not initially differ from the conventional one, but when it is necessary to remove the defect from the surface, the inductor is turned on at full power, to which a high frequency current is applied;

the inductor stops over the defective place and after the surface layer is melted with its help, the molten metal is removed from the surface of the ingot. If necessary, the melted or defective non-melted surface of the non-rolled part of the ingot is treated with a thermofreezing method.

The application of the proposed mill makes it possible to create a unit for combined casting and rolling, in which the equipment for heating a continuous ingot is excluded from the composition of the process equipment, while such heating will take place, since the heating function of the ingot before rolling takes on itself

j camp

At the mill being described, the quality of rolled products can be improved both by creating a special environment in the rolling zone and by possibly removing some defective spots from the surface of the continuous ingot.

In addition, there is a cost savings as a result of reducing the operating costs of rolling continuous ingot, and by reducing capital costs for the construction of a unit for the combined casting and rolling of metals. The capacity of the mill can be expressed in several hundreds of thousands of tons.

thirty.

Claims (4)

Invention Formula . A mill for rolling continuous ingot, mounted on guides along the rolling axis, a stand with driven rolling rolls, the supports of which are located in the projected racks of two cross-linked beds, and a drive of a reciprocating alternating rolling stand, different in that, for the purpose of unloading the main drive of the mill rolls and eliminating the separate drive of idle movement of the stand, the rolling stand of the mill is equipped with linear inductors installed in housings, 5 fortified between, stands of the cage, and located above and below the zone of passage of the rolled ingot, along it, in front of and behind the cage. 2. The mill according to claim I, characterized in that, Q, in order to ensure accurate movement of the rolled ingot through the cavity between the inductors, the end walls of the inductors housings, located on the inlet and outlet side of the rolled ingot to the rolling mill, are equipped with guide rollers, and support bodies the liners of which are provided with means for moving in a vertical plane relative to said end walls. 3. The mill according to claim 1, characterized in that, in order to create different intensity of heating of the surface layers of the continuous ingot, additional inductors with individual power supply are installed on the entrance side of the stand. W YU 4. A mill according to claim 1, characterized in that, in order to remove some surface defects from the non-rolled part of the ingot, a stripping device is installed on the end wall of the inductors located on the inlet side of the stand. 13 28