RU2528601C1 - Asymmetric metal rolling - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: proposed method comprises rolling with mismatch of rolls speed at three-roll gage. Better processing of metal at higher shear strain is ensured owing to peripheral speeds v₁…v_n of all rolls, 1…n respectively are set to be increased clockwise and in compliance with the relationship: v₁<v₂<…<v_i<…<v_n. At rolling, metal surface sections in contact with rolls of lower speed are decelerated to down the metal rolling-out. Sections in contact with rolls of higher peripheral speed are accelerated for metal larger rolling-out.

EFFECT: irregular distribution of rolling-out over strained blank cross-section.

4 dwg

Description

The invention relates to the processing of metals by pressure, in particular to the production of long products in multi-roll calibers.

A known method of rolling metal in a four-roll caliber using tension or pressure. The method involves the forced reporting of the peripheral speed to one pair of rolls of a four-roll caliber, not less than the speed at the exit of the caliber, and to the other pair, the message of speed not exceeding the speed of the metal at the entrance to the caliber (see AS USSR No. 261344, class B21B 1 / 00, published in BI No. 34, 1973).

The disadvantage of this method is the insufficient degree of redistribution of hoods compared with the claimed method.

The closest analogue is the method of rolling metal in a four-roll gauge, which involves rolling with a mismatch of the speeds of the pairs of rolls lying in different planes to slip the pair of rolls having a lower speed (see AS USSR No. 610581, class B21B 37/02 B21B 1/00, published in BI No. 22, 1978).

The disadvantage of this method is the relatively insufficient degree of shear deformation occurring in the volume of the metal when rolling in a multi-roll caliber.

The objective of the present invention is to provide such a method of rolling a section metal in which a high degree of uneven deformation in the volume of the metal and redistribution of the hoods over the cross section of the metal is achieved, which will allow for a more complete study of the metal due to large shear deformations.

The problem is solved in that in the known method of rolling metal in a multi-roll caliber formed by at least three rolls, including rolling with a mismatch of speed of the rolls, according to the invention, the peripheral speeds v ₁ ... v _{n of} all rolls, respectively, 1 ... n in caliber set with their increase in the direction of clockwise movement in accordance with the ratio: v ₁ <v ₂ <... <v _i <... <v _n .

A known method of rolling metal in a four-roll caliber using tension or pressure. The method involves the forced reporting of the peripheral speed to one pair of rolls of a four-roll caliber, not less than the speed at the exit of the caliber, and to the other pair, reporting the speed not exceeding the speed of the metal at the entrance to the caliber (see AS USSR No. 261344, class B21B 1 / 00, published in BI No. 34, 1973). The method is carried out with the rectilinear movement of the workpiece through the deformation zone and is intended to reduce the working forces during metal deformation in the four-roll stand gauge, while during the rolling process no significant shear deformation occurs in the metal.

A known method of rolling metal in a four-roll gauge, which involves rolling with a mismatch of the speeds of the pairs of rolls lying in different planes, to slip the pair of rolls having a lower speed (see AS USSR No. 610581, class B21B 37/02 B21B 1 / 00, published in BI No. 22, 1978). The method is carried out with the rectilinear movement of the workpiece through the deformation zone and is intended to ensure the regulation of the profile size during rolling in a four-roll caliber, while the rolling process does not cause significant shear deformation in the metal.

In the inventive method, the distinguishing features characterizing the inclusion of rolling with a mismatch of roll speeds in such a way that the peripheral speeds v ₁ ... v _{n of} all rolls, respectively 1 ... n in caliber are set with their increase in the direction of clockwise movement in accordance with the ratio: v ₁ <v ₂ <... <v _i <... <v _n . This allows you to create a new technical effect, which consists in a more complete study of the metal due to large shear deformations occurring in the volume of the metal during rolling due to a more uneven redistribution of the hoods over the cross section of the workpiece, which will allow to obtain a smaller grain score.

Based on the analysis of known sources of information, we can conclude that for a specialist the inventive method of rolling metal does not follow explicitly from the prior art, and, therefore, meets the condition of "inventive step".

The invention is illustrated by drawings, where:

- figure 1 shows the work rolls (1-3) located in the same plane and forming a three-roll caliber;

- figure 2 shows the work rolls (1-4) located in the same plane and forming a four-roll caliber;

- figure 3 shows a pair of horizontal rolls (1, 3) four-roll caliber;

v ₁ , v ₃ - peripheral speed of the rolls (indexes correspond to the positions of the rolls);

- figure 4 shows a pair of vertical rolls (2, 4) four-roll caliber;

v ₂ , v ₄ - peripheral speed of the rolls (indexes correspond to the positions of the rolls).

The proposed rolling method is implemented as follows.

In the work rolls 1-3 (figure 1), located in the same plane and forming a three-roll caliber, set the workpiece 4.

Three work rolls 1-3 (figure 1) set the peripheral speed, increasing in the direction of clockwise movement.

When rolling in a three-roll gauge (Fig. 1), where the peripheral speeds of all the rolls are set to increase in the clockwise direction, an accelerated metal flow zone is formed at the contact of the metal with the roller with the highest speed 3, and at the contact with the roller 1 having the lowest speed, a zone of slow flow of metal is formed. This leads to the possibility of a more uneven redistribution of the hoods over the cross section of the deformable workpiece and to obtain large shear deformations in the metal volume.

In the work rolls 1-4 (figure 2) located in the same plane and forming a four-roll caliber, set the workpiece 5.

Two horizontal work rolls 1 and 3 (FIGS. 2-3) and two vertical rolls 2 and 4 (FIGS. 2, 4) define peripheral speeds increasing in the clockwise direction.

When rolling in a multi-roll gauge (figure 2), where the values of the peripheral speeds of the rolls are set to increase in the clockwise direction, the zone of accelerated metal flow is formed at the contact of the metal with the roll 4 with the highest speed, and at the contact with the roll 1 having the lowest speed, a zone of slow flow of metal is formed. This leads to the possibility of a more uneven redistribution of the hoods over the cross section of the deformable workpiece and to obtain large shear deformations in the metal volume.

An example of a specific implementation 1.

For the manufacture of a bar of triangular section with rounded corners and an inscribed circle diameter of 6 mm with enhanced mechanical properties, a round billet with a diameter of 8 mm was used from steel of steel grade 45. Rolling was carried out in a stand with a three-roll caliber with all drive rolls. The peripheral speed of the first roll was 6.99 rad / s, the second - 7.06 rad / s, the third - 7.14 rad / s. As a result of uneven drawing over the metal section, the front end of the workpiece at the exit from the rolls bent in two directions: in the vertical and horizontal. At a length of 50 mm of the end of the workpiece emerging from the rolls, the bend in the direction of the positive z axis was 4 mm, and in the direction of the negative y axis, 2 mm.

Thus, in the caliber of the cage, including three rolls having different peripheral speeds, there is a significant shear strain, due to which the front end of the workpiece bends in two planes, mainly towards the roll with the lowest peripheral speed.

An example of a specific implementation 2.

For the manufacture of a square-sectioned bar with rounded corners and an inscribed circle diameter of 6 mm with enhanced mechanical properties, a round billet with a diameter of 8 mm was used from steel grade 45. Rolling was carried out in a stand with a four-roll caliber with all drive rolls. The peripheral speed of the first roll was 7.15 rad / s, the second - 7.87 rad / s, the third - 8.37 rad / s and the fourth - 8.94 rad / s. As a result of uneven drawing over the metal section, the front end of the workpiece at the exit from the rolls bent in two directions: in the vertical and horizontal. At a length of 50 mm of the end of the workpiece emerging from the rolls, the bend in the direction of the positive z axis was 4.4 mm, and in the direction of the positive y axis, 2.8 mm.

Thus, in the caliber of the stand, which includes four rolls with peripheral speeds, the magnitude of which increases in the clockwise direction, a significant shear deformation occurs, due to which the front end of the workpiece bends in two planes, mainly towards the roll with the lowest peripheral speed.

Thus, in the caliber of the stand, a more complete study of the metal is provided due to the significant unevenness of the redistribution of the hoods in two planes and, as a result, the creation of large shear deformations. At different ratios of the peripheral speed of the rolls in the caliber, various variants of the uneven distribution of hoods will be observed, which affect the degree of metal working due to large shear deformations, which will allow to obtain the required grain score.

Based on the foregoing, we can conclude that the claimed method is workable and eliminates the disadvantages that occur in the prototype, which is confirmed by an example implementation. Accordingly, the claimed solution may be applicable in the rolling industry, and therefore, meets the condition of "industrial applicability".

Claims (1)

The method of asymmetric rolling of long products in a multi-roll gauge formed by at least three rolls, including rolling with a mismatch of roll speeds, characterized in that the peripheral speeds v ₁ ... v _{n of} all rolls, respectively, 1 ... n in the gauge are set with their increase in the direction clockwise movements in accordance with the ratio: v ₁ <v ₂ <... <v _i <v _n .

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