RU2609768C1 - Method of step-by-step rolling flat long billet - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: method relates to the pressure treatment of metal. It includes deformation of lengthy flat billet in the shaft with a smooth barrel. This deformation happens straightforward and backwards after the step movement of the billet during reciprocation of the shaft. The increase of billet deformation is ensured by the fact that deformation is carried by an upper shaft during its reverse rotation, the upper shaft is reciprocatingly moved across the billet along the work surface of the lower shaft, the stepwise movement of the billet is carried out in the extreme positions of the upper shaft after it goes outside the billet.

EFFECT: method can be used for rolling flat long billets like bands and strips made from hard wrought steels and alloys.

4 cl, 7 dwg

Description

The inventive object relates to the processing of metals by pressure and can be used for rolling long flat billets such as tapes and strips, mainly from hard to deform steels and alloys.

The closest in combination of features to the claimed object is the method of step rolling of tapes selected as a prototype, which is described in the description of the invention to the patent of the Russian Federation No. 2521764, published 10.072014. The known method involves the deformation of a flat lengthy workpiece in rolls with a smooth barrel, forward and reverse after stepwise movement of the workpiece during the reciprocating movement of the roll. The workpiece is deformed by direct and reverse when the axes of the rolls are reciprocated and the workpiece is freely moved along the rolling axis in the direction opposite to the direction of movement of the roll axes during workpiece deformation when the workpiece is forced to move towards the finished profile during the formation of the gap between the workpiece and the work surface rolls. The axial forces in the workpiece during its reverse deformation are reduced due to the fact that the forced movement of the workpiece before the reverse stroke is additionally carried out by the amount of free movement of the workpiece, while the free movement of the workpiece does not exceed the calculated value.

The claimed object and the prototype match the following essential features. Both methods of step rolling include the deformation of a flat long workpiece in rolls with a smooth barrel, forward and reverse, after stepwise movement of the workpiece during reciprocating movement of the roll.

When using the claimed object is expected to achieve a technical result, which consists in increasing the degree of deformation of a flat lengthy workpiece, mainly from hard to deform steels and alloys.

Analysis of the technical properties of the prototype, due to its features, shows that the following reasons hinder the receipt of the expected technical result when using the prototype. Hardly deformable steels and alloys with deformations of more than 50-55% are strongly “blown off,” and their further deformation in the longitudinal and especially in the transverse direction is impossible due to the very high loads on the rolls and the strength characteristics of the rolling stands. The deformation zone in the rolling rolls is localized only in the area of metal contact with the upper and lower rolls. When rolling a flat long workpiece, a deformation zone is formed along the entire width of the rolls, and for difficultly deformed alloys it is not possible to provide a high degree of deformation of a flat long workpiece due to the large forces on the rolls and large rolling moments. And to deform flat long workpieces in the transverse direction in the prototype is generally impossible.

The claimed object is based on the task of creating such a method of step rolling of a flat long billet, in which an improvement by introducing new elements would make it possible to achieve a technical result when using the inventive object, which is to increase the degree of deformation of a flat long billet of difficultly deformed steels and alloys.

The essence of the proposed facility is as follows. The step-by-step rolling method for flat long workpieces involves deforming a flat long workpiece in rolls with a smooth barrel with forward and reverse motion after stepwise moving the workpiece during reciprocating movement of the roll. A distinctive feature of the claimed object is the following. The deformation of a flat long workpiece is carried out by the upper roll with reverse rotation, while the upper roll is reciprocated across the workpiece along the working surface of the lower roll, and the stepwise movement of the workpiece is carried out in the extreme positions of the upper roll after it leaves the workpiece.

In special cases of use, the claimed object is characterized in that:

- in the extreme positions of the upper roll, after it leaves the flat long workpiece, the lower roll is rotated around its longitudinal axis by the step of moving the workpiece simultaneously with its movement;

- stepwise movement of a flat lengthy workpiece is carried out in pulling rolls with a smooth barrel, in which the workpiece is additionally crimped in thickness;

- the step of moving a flat long workpiece is 0.2-1.0 the length of the deformation zone of the workpiece on the lower roll.

When using the inventive object, it is expected to achieve a technical result, which consists in increasing the degree of deformation of a flat lengthy workpiece of difficultly deformed steels and alloys.

Between the totality of the essential features of the claimed object and the achieved technical result, there is the following causal relationship. The deformation of a flat lengthy workpiece by the upper roll with reverse rotation, while the upper roll is reciprocated across the workpiece along the working surface of the lower roll, and the stepwise movement of the workpiece is carried out in the extreme positions of the upper roll after it leaves the workpiece, provide deformation at each stroke of the upper roll billets in the transverse direction with the flow of metal in the broadening of the flat long billets in the transverse, and not in the longitudinal direction, as in the prototype e. Moreover, in the axial section of the rolls, deformation is currently not carried out over the entire width of the rolls, as in the prototype, but only locally on a part of the width of the flat workpiece. The flat long workpiece is periodically moved forward by a step equal to 0.2-1 the size of the deformation zone, and then the direction of rotation and the direction of movement of the upper roll are switched in the opposite direction and the flat long workpiece is deformed in the opposite direction. The reciprocating movement of the upper roll across the flat lengthy workpiece with an adjustable stepwise feed forward provides the deformation of the flat workpiece in the transverse direction with the flow of metal in broadening. Local deformation of a flat long billet along its width allows working hard to be deformed steels and alloys in the transverse direction at very high compression ratios, since the rolls do not experience heavy loads.

Turning the lower roll around its longitudinal axis by the step of moving the workpiece at the same time as it moves in the extreme positions of the upper roll, after it leaves the flat long workpiece, allows for each deformation of the upper roll to deform the workpiece locally on a new section of the lower roll, which prevents an increase in the radius the curvature of the working surface of the lower roll as a result of its premature wear and helps to increase the uniformity of deformation of the workpiece along its length.

The stepwise movement of a flat lengthy workpiece in pulling rolls with a smooth barrel, in which the workpiece is additionally squeezed in thickness, provides for step-by-step movement of the workpiece by the stand rolls while compressing the workpiece in thickness to remove waves generated during its local deformation in the rolls of the previous stand.

The installation of the lower roll with the possibility of adjustable rotation relative to the longitudinal axis, which is parallel to the longitudinal axis of this lower roll, allows you to change the distance between the working surface of the lower roll and the working surface of the upper rolls, change the length of the deformation zone and allows you to adjust the degree of compression of a long flat workpiece in one pass of the upper roll .

Depending on the amount of compression and the pitch of the flat long workpiece, periodic small waves are formed on its lower surface from the side of the lower roll, located across the flat workpiece. These waves during subsequent rolling of a flat long workpiece in smooth rolls are smoothed over the entire length of the workpiece. The maximum wave height is formed at a step equal to the length of the deformation zone. The minimum wave height is formed at a step equal to 0.2 of the length of the deformation zone. It was experimentally determined that the regulation of the step of moving a flat long workpiece within 0.2-1.0 of the length of the deformation zone of the workpiece on the lower roll allows you to adjust the height of the waves located across the flat workpiece, which are smoothed during subsequent rolling of the workpiece. By deforming a flat lengthy workpiece from difficultly deformed steels and alloys in the transverse and longitudinal direction, isotropy of the properties of a flat long workpiece in two directions is ensured.

The essence of the claimed object is illustrated by illustrative materials, which depict:

in FIG. 1 is a front view of the mill stepping rolling of long lengthy blanks;

in FIG. 2 is a view along arrow “C” in FIG. one;

in FIG. 3 is a side view of the mill stepping rolling of a long lengthy workpiece when performing the device for the stepwise movement of the flat workpiece on the basis of the rolling mill.

in FIG. 4 is a top view of the upper roll and lower roll of the mill when rolling a flat lengthy workpiece;

in FIG. 5 is a side view of the upper roll and the lower roll, which is rotated relative to the longitudinal axis, which is parallel to the longitudinal axis of the lower roll, in a position corresponding to the minimum deformation;

in FIG. 6 is a side view of the upper roll and lower roll, which is rotated relative to the longitudinal axis, which is parallel to the longitudinal axis of the lower roll, in a position corresponding to the maximum deformation;

in FIG. 7 is a side view of the upper roll and lower roll, which is made with a variable radius and rotated by a predetermined angle around its longitudinal axis;

In the drawings, the following notation is used:

1 - bed;

2 - upper roll;

3 - lower roll;

4 - clip;

5 - lead screw;

6 - gear;

7 - gear;

8 - gear;

9 - reversible electric drive;

10 - reversible electric drive;

11 - a guide;

12 - guide;

13 - a device for the stepwise movement of a flat workpiece;

14 - the upper roll of the device for the stepwise movement of the flat workpiece;

15 - lower roll of the device for stepwise movement of a flat workpiece;

16 - drive incremental rotation of the lower roll 3;

17 - the longitudinal axis of rotation of the lower roll 3;

18 - the longitudinal axis of the lower roll 3;

19 - guide rollers;

20 - feed drum;

21 - receiving drum;

22 - flat long workpiece.

In a specific exemplary embodiment, the method of step rolling of flat long workpieces is as follows. The mill stepping rolling of flat lengthy workpieces contains (Fig. 1 and Fig. 2) installed in the frame 1 using vertical mounting mechanisms, the upper roll 2 with a smooth barrel and the lower roll 3 with a smooth barrel. The lower roll 3 is fixed from rotation around its axis. The upper roll 2 is mounted with the possibility of reciprocating movement along the working surface of the lower roll 3. The longitudinal axis O1-O1 of the upper roll 2 is located in a vertical plane that is perpendicular to the vertical plane in which the longitudinal axis O2-O2 of the lower roll 3 is located (Fig. 4 )

To ensure the reciprocating movement of the upper roll 2 (Fig. 2) along the working surface of the lower roll 3, the upper roll 2 is installed in a ferrule 4, which is connected through a spindle 5 and the gear system 6, 7 and 8 with a reversible electric drive 9 with an adjustable number speed, which is mounted on top of the bed 1. The rotation mechanism of the upper roll 2 is mounted on a cage 4 and contains a reversible electric drive 10 with an adjustable speed and with a gearbox. In parallel with the lead screw 5, guides 11 and 12 are fixed, on which, with the possibility of moving the lead screw 5, they can be fastened with a clip 4 with an upper roll 2 and an electric drive 10.

A device 13 for stepwise moving a long flat workpiece is made on the basis of a rolling stand in which an upper roll 14 with a smooth barrel and a lower roll 15 with a smooth barrel are installed for additional compression of the flat workpiece in thickness during its stepwise movement (Fig. 3).

The lower roll 3 can be equipped with a stepwise rotation drive 16, which is synchronized with the drive of the device 13 for stepwise movement of a flat lengthy workpiece (Fig. 1 and Fig. 3).

The lower roll 3 can be installed with the possibility of fixed rotation relative to the longitudinal axis 17, which is parallel to the longitudinal axis of this lower roll, to control the degree of compression of a flat long workpiece. In FIG. 5 shows the lower roll 3, which is rotated by a predetermined angle and fixed relative to the longitudinal axis 17, which is parallel to the longitudinal axis of the lower roll 3, in a position corresponding to the minimum deformation of a flat long workpiece characterized by a thickness h1. In FIG. 6 shows the lower roll 3, which is rotated by a predetermined angle and fixed relative to the longitudinal axis 17, which is parallel to the longitudinal axis of the lower roll 3, in a position corresponding to the maximum deformation of a flat long workpiece characterized by a thickness h2.

It is desirable that the radius of the lower roll 3 is 0.5-2.0 the radius of the upper roll 2, for example, in a specific example, the radii of the rolls are selected the same.

The lower roll 3 can be made with a variable radius, which varies from 0.5 to 2.0 of the radius of the upper roll along the length of the working surface and is equipped with a rotation drive at a predetermined angle around the longitudinal axis 19, which coincides with the longitudinal axis of the roll 3. In a specific example the lower roll 3 is rotated by an angle corresponding to the equality of the radii of curvature of the corresponding section of the lower roll 3 and the upper roll 2, and is fixed in this position (Fig. 7).

In the case of rolling strips, a long, lengthy billet is fed for rolling from the feed drum 20, which is located in front of the rolling device with the upper roll 2 and lower roll 3. After rolling, the tape is wound onto the receiving drum 21, which is located after the device 13 for stepwise moving the flat billet, made on the basis of a rolling stand (Fig. 3).

In a specific example, the inventive method of step rolling flat long workpieces is carried out during operation of the mill as follows. At the beginning of the process of rolling a long flat billet, the cage 4 with the upper roll 2 using a reversible electric drive 9, the gear system 6, 7, 8 and the spindle 5 are moved relative to the frame 1 in one of the extreme lateral positions.

From the feed drum 20, the long flat billet 22 is moved forward along the guide rollers 19 above the lower roll 3, passed through the device 13 for stepwise moving the flat billet, which is made on the basis of the rolling stand, and fixed on the receiving drum 21.

Using the vertical installation mechanism, the necessary clearance is established between the upper roller 2 and the lower roller 3 to realize the required compression of a flat long workpiece. They include a reversible electric drive 10, which rotates the upper roll, and a reversible electric drive 9, which through the screw 5 provides reciprocating movement of the upper roll 2 across the flat workpiece 22. The number of revolutions of the reversible electric drive 9 and the reversible electric drive 10 is set so that the linear rotation speed of the upper roll 2 was equal to the linear velocity of the upper roll 2 across the flat long workpiece 22.

The deformation of the flat long workpiece 22 is carried out by the upper roll 2 when it is moved by the lead screw 5 in the guides 11 and 12 across the flat long workpiece 22 along the working surface of the lower roll 3. After the upper roll 2 has exceeded the limits of the flat long workpiece along its width, the limit switches are activated, which are electrically connected to the drive of the device 13 for the stepwise movement of a flat long workpiece, with a reversible electric drive 10, which rotates the upper roll, and with a reversible electric drive One 9, which through the screw 5 provides reciprocating movement of the upper roll 2 across the flat workpiece 22. When this flat long workpiece 22 moves relative to the lower roll 3 by a step, the direction of rotation of the upper roll 2 is reversed and the upper roll 2 begins to move across the workpiece in the opposite direction, returning to its original position, and again deforms the workpiece. In the extreme positions of the upper roll 2, after it leaves the flat long billet 22, everything is repeated. The step of moving a flat long workpiece is 0.2-1.0, for example, 0.5 of the length of the deformation zone on the lower roll 3.

The reciprocating movement of the upper roll across a flat lengthy workpiece with its adjustable feed step forward provides the workpiece deformation in the transverse direction with the metal flowing into broadening. Depending on the amount of compression of the flat workpiece and the step of its movement, periodic transverse waves are formed on its lower surface. After passing a long flat billet through the smooth rolling rolls 14 and 15 of the device 13 for stepwise moving the flat billet, these waves are smoothed out.

When supplying the lower roll 3 with a step-by-turn drive 16, which is synchronized with the drive of the device 13 for step-by-step movement of a flat long workpiece (Fig. 1 and Fig. 3), with each step of moving the flat workpiece 22, the lower roll 3 also rotates simultaneously with the movement of the flat long workpiece . At the next working stroke, the upper roll 2 will deform the flat long billet 22 in a new section of the lower roll 3, which prevents the radius of curvature of the working surface of the lower roll 3 from being prematurely worn and helps to increase the uniformity of deformation of the flat long billet along its length.

In some cases, when rolling strips from difficultly deformed alloys, it is necessary to select the optimal length of the deformation zone. If the lower roll 3 is mounted with the possibility of a fixed rotation about a longitudinal axis 17, which is parallel to the longitudinal axis of this lower roll, then to control the degree of compression of the flat long workpiece 22, it is sufficient to turn the lower roll 3 around the longitudinal axis 17 by a predetermined angle, providing a given length of the deformation zone, and fix it in this position.

If the lower roll 3 is made with a variable radius, which varies from 0.5 to 2.0 of the radius of the upper roll along the length of the working surface, and is equipped with a rotation drive for a given angle around the longitudinal axis 18, which coincides with the longitudinal axis of the lower roll 3, then for selection of the optimal length of the deformation zone when rolling strips of difficult to deform alloys, it is enough to turn the lower roll by a predetermined angle, which provides the specified length of the deformation zone, and fix it in this position.

The deformation of a long flat billet 22 during the rolling process between the upper roll 2 and the lower roll 3 is not carried out simultaneously over its entire width, but locally, sequentially in parts, in the transverse direction, which allows the processing of difficultly deformed steels and alloys with very large compression ratios, so as in this case, the upper roller 2 and the lower roller 3 do not experience heavy loads.

Claims (4)

1. The method of step rolling flat long billets, including the deformation of a flat long billets in rolls with a smooth barrel, forward and reverse after stepwise movement of the workpiece during the reciprocating movement of the roll, characterized in that the deformation of a flat long billets is carried out by the upper roll in the process of its reverse rotation and reciprocating movement across the workpiece along the working surface of the lower roll, while the stepwise movement of the workpiece is carried out in extreme positions of the upper roll after it leaves the workpiece. 2. The method according to p. 1, characterized in that in the extreme positions of the upper roll after it leaves the flat long workpiece, the lower roll is rotated around its longitudinal axis by the step of moving the workpiece simultaneously with its movement. 3. The method according to p. 1, characterized in that the stepwise movement of a flat lengthy workpiece is carried out in pulling rolls with a smooth barrel, in which the workpiece is additionally crimped in thickness. 4. The method according to p. 1, characterized in that the step of moving a flat long workpiece is 0.2-1.0 the length of the deformation zone of the workpiece on the lower roll.

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