SU899170A1 - Strip rolling method - Google Patents

Description

one

The invention relates to rolling production, in particular to the production of stripes on continuous and reversible plate rolling mills.

A known method of rolling strips in a line of a continuous sheet mill with a vertical stand, according to which, in order to reduce the end cut, the sheet is crimped with variable compression along the longitudinal axis of the finished roll by moving the vertical rolls when the front and rear ends are crimped. less than its middle part

However, this method can be carried out only on mills equipped with vertical stands, which limits its scope.

Closest to the invention to the technical essence and the achieved result is a method of rolling sheets, including a broadening passage in which various deformations of the ends and the middle part of slab 2 are carried out.

A disadvantage of the known method is the impossibility of separately forming a configuration. the front and rear ends of the rolls, which leads to increased edge trimming.

The purpose of the invention is to reduce the end edge of the strips when rolling in a mill line with horizontal rollers.

The goal is achieved by the fact that according to the rolling method, which includes a broadening passage, in which different deformations of the ends and the middle part of the slab are carried out, the broadening passage is carried out with different deformations along the length of the roll barrel,

The 20 values of the relative crimping of the edges of the slab corresponding to the front and rear ends of the finished roll are 1: (1.1-10). 3 In FIG. 1 and FIG. Figure 2 shows the configuration of the front and rear end sections of the rolls; in fig. 3 and FIG. t is the configuration of the mountaineers of the front and rear ends of the finished roll (top view). The method is carried out as follows. The initial slab is transported to the rolling stand with horizontal rollers, while the longitudinal axes of the slab and the finished roll coincide with the mill axis. After turning the slab on 90, it is set into a cage and compression is performed under the condition of non-uniform deformation along the length and width, while the relative deformation of the slab segment corresponding to the rear end of the finished one is 1.1-10.0 times greater than the strain of the slab segment, which corresponds to the front end of the finished roll, and the relative compression at the beginning and end of the passage is 0, less compression in rolling the middle part of the slab. Variable deformation is carried out by changing the gap between the rolls during the passage with the help of pressure devices. In this case, the right and left pressure devices change the gap between the rollers at different speeds. The higher rate of change of the gap leads to an increase in the strain, i.e. With greater speed, the pressure device moves where the section corresponding to the rear end of the finished roll is deformed. After the first pass, the roll rolls over 90. As a result of the variable deformation in the first pass along the length and width of the slab after turning over, the wide upper and lower faces have a wide shape along the entire length. In this case, the concavity of the wide faces increases from the front to the rear end of the roll. The subsequent rolling in horizontal rolls of rolls with concave wide edges leads to the fact that the extreme sections receive a large deformation and, accordingly, stretching, which ensures the equality of the total extracts of the middle and extreme sections of the finished roll. Enhance the concavity of the wide faces of the roll to the rear end of the compare; The front side helps to increase the stretching of the extreme sections of the rear end and thereby improves the shape of the end of the finished roll. An increase in the relative deformation along the length of the roll barrel of the slab section corresponding to the rear end of the finished roll, 1.1-10 times compared to the end of the roll, corresponding to the end of the finished roll, practically provides a rational form of the front and rear ends of the roll in different production conditions. . The lower limit (1.1) of the range corresponds to rolling on reversing mills. In this case, in each odd pass, the front and rear ends of the rolled stock correspond to the front and rear ends of the finished roll; in each even pass, the front end of the roll to be set corresponds to the rear end of the finished roll, and the rear end of the rolled stock corresponds to the front end of the finished roll, i.e. the difference in the shape of the front and rear ends on the finished roll is reduced, an odd total number of transitions, and consequently, the alignment of their configuration is provided with a smaller non-uniformity of deformation along the length of the roll barrel. Before longitudinal rolling to a predetermined thickness, one billet is rolled with variable deformation during rolling and the length of the roll barrel. During rolling, the relative deformation along the edges of the slab varies from 0 to 2.5 (in the area corresponding to the front end of the finished roll) and from O to 2.75 (in the section corresponding to the rear end of the finished roll). Those. The relative deformation along the length of the roll of the roll of the section that corresponds to the rear end of the finished roll is 2.75 / 2.5 1.1 times greater than the relative deformation of that section that corresponds to the front end of the finished roll. After rolling the slab with variable deformation, during rolling and the length of the roll barrel, it is turned 90 °. The broad faces of the slab have a variable concavity. The thickness of the extreme sections

58

equal to 20 mm. The thickness of the slab in the middle part at the front end is 19.5 and at the rear 19, / + 5 mm. The second billet has flat wide edges, since it was not rolled with variable deformation psr the length of the roll-a barrel. Rolling to final thickness was carried out in two reversing cages. Modes of reductions when rolling two blanks are the same and are given in table. one.

The results of measurements of the length of the uneven ends of the finished rolls are given in table. 2

As can be seen from the table. 2, the application of the invention makes it possible to reduce the length of the front and rear uneven ends, respectively, 6.1 and 6.5 times.

When rolling on an irreversive mill, the shape of the roll is deteriorated due to a significant increase in the length of the uneven butt end of the rear cock

An example. Rolling on a non-reversible sheet mill of two initial billets 20x90x120 mm.

Before passes, in which the roll was rolled in horizontal rollers to obtain the final thickness, one pass with variable deformation was made during the rolling and the length of the roll barrel. The longitudinal axis of the original blank in this passage is perpendicular to the longitudinal axis of the finished roll. In the course of rolling, the relative deformation changed from O in the extreme areas with the capture and release of metal from the rolls to 2.5 and 2, in the middle part of the original billet in the areas corresponding to the front and rear ends of the finished roll, i.e. along the length of the roll barrel, the strain increases by 5 times.

After turning over to 90, the wide faces of the slab have a full length. The thickness of the extreme sections is 20 mm, and the average thickness is 19.5 and 17.5 n. From the front and rear ends of the workpiece, respectively. After the passage with variable deformation, the billet is rolled on an irreversive mill to a final thickness.

The second blank has a flat

706

wide edges. Compression modes are given in table. 3

The results of measurements of the length of the uneven ends of the finished rolls are given in table. k,

The invention makes it possible to reduce the length of the front and rear uneven ends by 5.9 and 7.2 times, respectively.

The adverse rolling conditions of the sheets are created when rolling with a large total stretch of convex starting billets (with transverse thickness variation) on an irreversible mill. In this case, in order to reduce the length of the uneven ends, an uneven deformation along the length of the roll barrel should be applied, corresponding to the upper limit of the range indicated in the materials of the application.

Example. Rolling on non-reversible mill convex source blanks.

The dimensions of the original blanks 25x90x120 mm. In this case, the blanks have a transverse thickness variation equal to O, mm.

In the first pass, the workpiece is rolled with variable deformation during rolling and the length of the roll barrel in a direction perpendicular to the longitudinal axis of the finished p-roll. The strain distal carrier changes from O in the extreme sections during rolling to 2 and 2QZ in the areas corresponding to the front and the rear ends of the finished roll, i.e. the relative deformation at the rear end is 10 times greater than the deformation at the front end of the roll.

After turning to 90, the billet has concave wide edges. The thickness of the workpiece is 25 mm at the extreme areas and, 5 and 20 mm at the middle areas, respectively, at the front and rear ends. Modes of reductions subsequent non-rolling rolling are given in table. 5 The results of measuring the length of uneven ends are given in Table. 6

8991708

Table 1

Front (1)

39.7

Rear (I-)

51.2

1About 2

83.8 (6.1 times)

84.9 (6.5

times)

Table 3

C

7 5 3,5

five

6

II

i Length of uneven torus- Reduction

Ends

Front 1,) 32.5 5., 5 Rear (C) 73i5 10.2

25

20

15 10

7

five

3.5 2.5

89917010

Continued table. 3

28.6

thirty

28.6

Table

83 (5.9 times) 86 (7.2 times)

T-face 5

20

25

33.3

thirty

28.6

thirty

28.6

2U

89917012

n

Ends

The length of the rough ends of the finished rolls, mm

Preferred Guy

Front

Claims (2)

1. Steel, M., Metallurgists, 1975, ff 3, p. aitZ-ZifS. 2. USSR author's certificate number 716653, cl. B 21 B 1/38, 1980. . with:; about -X.Vik. llhhh U : x f % "