RU1782682C - Method of rolling rectangular blanks - Google Patents

Abstract

Usage: rolling billets of rectangular cross section from billets of large sizes, for example, continuous ingots in the form of wide slabs or hollow ingots. SUMMARY OF THE INVENTION: the compression of the initial preform is carried out from two opposite surfaces at angles of 45 °; to them. The compression in each of the two plastic deformation zones is one-way. Plastic deformation is carried out with the mutual displacement of two deformation zones. As a result of the deformation, the workpiece is formed and separated from the rest of the metal volume. 1 wpp, 5 ill.

Description

The present invention relates to ferrous metallurgy and can be used in the rolling of billets of rectangular cross section from initial billets of large sizes, for example, ingots, continuous casting in the form of wide slabs or hollow ingots.

There is a method of rolling a wide slab with compression and separation of cross-section blanks of uneven width, which allows to increase productivity, casting a large cross-section workpiece by continuous casting, and then dividing it by uneven width by crimping in calibrated rolls, to obtain several rectangular blanks special case of square cross-section. The disadvantage is that the quality of the workpieces is poor due to uneven compression and the presence near the corners of metal sections with a very small degree of deformation achieved during the rolling process.

The closest analogue of the claimed technical solution, both in terms of technical nature and the achieved result, is a method comprising sequential deformation of the initial workpiece in pairs of calibrated rolls with uneven compression and the formation of workpieces separated by a jumper. Further, during the mutual rotation of the blanks, while turning them around the longitudinal axes, the bridge is destroyed and the blanks are separated. The disadvantage is poor quality due to uneven deformation. The angles at the tops of the gauges are formed

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from the first pass, and the metal near the corners of the workpiece always remains in this (corner) zone and has a lower temperature, since it cools faster. The degree of deformation and, consequently, the development of the cast structure is much less than in the deformation zones by the protrusions of the rolls, where jumpers are formed.

The present invention aims to provide improved metal quality. This goal is achieved due to the fact that the compression is carried out from two opposite surfaces of the original workpiece at angles of 45 ° to them. In this case, the reduction in each of the two zones of plastic deformation is one-sided. In addition, the deformation is carried out with the mutual displacement of two zones of plastic deformation.

The common features with the prototype are the operations of crimping rolls that are uneven in width of the initial billet, as well as the separation from the initial section of the rectangular billet formed during plastic deformation.

Distinctive, in comparison with the prototype features is the implementation of the compression at angles of 45 ° from two opposite surfaces of the original workpiece, with unilateral compression in each of the two zones of deformation. In addition, it is contemplated that two zones of plastic unilateral deformation are displaced relative to each other. It is precisely due to these distinguishing features that the goal is achieved, since the casting structure of shear deformation is intensively worked out, and the corner zones of the profile are formed only in the last pass.

Figure 1 shows a diagram of the deformation of an annular hollow ingot in the first pass; in FIG. 2 - in the last pass; in FIG. 3 is a diagram of two zones of unilateral plastic deformation with a displacement of these zones one relative to the other; Fig. 4 is a rolling diagram with a jumper medium separating a rectangular profile from an initial billet; in FIG. 5 is a rolling embodiment in which the axes of two work rolls are mutually perpendicular. The following notation is accepted. The work roll 1 has cylindrical sections of smaller diameter 2 and larger 3, and the conical section 4 serves to support the surface of the ingot 5. The conical section 6 of the second roll maintains the second surface of the workpiece, while its intense one-sided deformation

cylindrical sections of the roll of smaller diameter 7 and larger diameter 8 are realized. The second work roll 9, like the first, is connected to the drive. Last pass

is carried out with plastic deformation of the rectangular profile by the roll 10 with cylindrical sections 11 and 12. The conical section 13 is a reference. Cylindrical sections 14 and 15 of the roll 16

provide the formation of the final cross section of the workpiece 17. Here is an operational description of the method.

The first step is to feed the original workpiece, for example, the resulting

continuous casting, in exposed work rolls. Continuous casting produces either a wide slab or an annular hollow ingot with an axis O2 (see Figs. 1, 2). After separation of the seed and its removal

the ingot is fed into the rolls (perpendicular to the plane of the drawing, Fig. 1; 2), at a temperature (for steel ingots) of 850-1150 ° C. The second operation — compression of the ingot in the first pass — is carried out at a temperature

850-1150 ° C. The axis of roll 1 is inclined at an angle of 45 ° to the surfaces of the original ingot (and the OlOa mow). The cylindrical section 2 of the roll 1 deforms the ingot in that part which is determined from the initial workpiece, and the section of the roll 3 deforms along the plane AB along the surface D (see Fig. 1,2), while section 4 supports the surface of the ingot 5. The second surface E

holds the conical section 6, and the cylindrical sections 7, 8 of the roll 9 deform the ingot. Surfaces C and D (Fig. 1, 2) are the main deforming surfaces. In fact, two zones of plastic deformation are realized: one between the surfaces D and E, and the second between the surfaces G and y, while the surfaces E and are fixed, i.e. in both zones the deformation is one-sided, and the directions

currents are opposite. The crimped zones in FIG. 1 (and FIG. 2) are shaded. Further, the third and subsequent operations consist in compressing the ingot with subsequent pairs of rolls, the number of which depends on the size of the initial ingot and the final rectangular section. The last pass, (see Fig. 2) provides the formation of a cross section of a rectangular billet 17, which near the point O can be connected to the ingot 5

thin jumper. The roller 10 has cylindrical sections 11 and 12, which form two adjacent, mutually perpendicular, faces of the workpiece.

One of the surfaces — the cylindrical surface D of the roll 12 part — undergoes active plastic deformation (the crimped portion near the cylinder 6 is shaded), and the second, the end surface of the roll 12 part, as well as the cylindrical part of the roll 11, provide the formation of a profile from the one already separated from the steel 5 metal. The conical section 13 does not undergo plastic deformation, it only supports the surface of the ingot and prevents the formation of local metal protrusions on this surface.

The section of the second roll 14 carries out active plastic deformation along the surface C, and the section 15 of the roll 16 forms one of the faces of the cross section of the workpiece 17. The top of the cross section angle F (see Fig. 2) is formed only in the last pass, and under conditions of intense deformation, - henna, which provides good properties of the metal.

intense separation rollers are realized only in the pinch zones of the cross section, where it is double-sided).

The deformation (see Figs. 1-3) is carried out in cylindrical rolls whose axes Oi02 and Oz04 (Fig. 3) are inclined at 45 ° angles to the surfaces of the initial workpiece (KDN and FAP). In FIG. Figure 3 shows only sections of rolls 3 and 7 that undergo active plastic deformation; from passage to passage, the surfaces of WFH and MDC (move to the axis of the ingot, tending to the lines О, ОК). In the last pass, it is possible (see Fig. 4) to increase the diameter of the roll-section 7 and reduce the diameter of the section 2, so that the roll 7 with the end surface (AB) will ensure the overlap of the entire section and the separation of the workpiece 17 (cut along AB), FIG. .Z. In the embodiment of FIG. The 5 axes of the rolls are not parallel, but perpendicular to each other, and the rolls can separate the workpiece 17 from the ingot 5 by a gap along the formed jumper.

The fourth operation consists in separating the formed workpiece from the ingot, which can be carried out in the rolls of the last rolling stand or by oxygen (plasma) cutting, after which the ingot, if it is curved, is unbent and straightened. If the rolling is carried out with the separation (sequential) of the workpieces from a wide slab (perpendicular to the plane of the drawing, Figs. 1, 2), then in this case, after the workpiece is separated, it is necessary to correct it. The fourth operation is carried out at a temperature (for steel) of 810-1010 °. The proposed method provides for the implementation of two zones of plastic deformation (see Fig. 3), wherein each of the zones is one-sided. In one of them (above the reference plane AOB - Fig. 3), the deformation is carried out by the surface EFH in the direction of 45 ° with the surface of the ingot 5EF - in the direction of the surface BN, along which there is no reduction (YOU only support if necessary, to avoid bending ingot). The second zone is below the BOA (see Fig. 3) and is carried out by the MDS surface towards the surface of AP. Here, the deformation is also one-sided (there is no reduction along the AR) and also at an angle of 45 ° to the surface of the ingot, but in both zones the directions of flow are opposite, and the deformation is carried out with the mutual displacement of both zones of plastic deformation (one of them is higher than AOW, and the second is lower than AOW ), provides intensive shear deformation over the entire thickness (along the AOB), (with known methods, we give a specific example of the method. Hollow steel ingots are cast with an inner diameter of 2000 mm and a thickness of 160-170 mm by pouring steel into istallizator with the mandrel. Here, the ingot is formed, with which the mold and the mandrel is rotated and simultaneously at a rate 0.2-0,4 m / min. is moved vertically. After completion of the crystallization, at a distance of at least 600-700 mm from the end of the liquid pool

there are three stands whose rolls are inclined to the vertical axis of the cylindrical ingot at angles of up to 1-4 °, i.e. perpendicular to the helix describing the trajectories of the ingot particles. At ingot speed

vertically vi 0.2-0.4 m / min, its peripheral speed is V2 10-12 m / min, for example, when vi 0.4 m / min, V2 10 m / min, the angle is 0.04 rad. (2.3 °). In the first stand, with a diameter of section 3 (see FIG. 1), 800 mm and section 7-580 mm of compression are equal, respectively, to 50 mm and 40 mm (these are the largest reductions in AOW, and with distance from AOW they decrease to zero. The initial thickness is 155 mm, and the size at an angle of 45 ° (along the AOW)

155. V2 219 mm. In the second stand, the reductions are 40 mm respectively (in both rolls), and in the third stand 10 mm and 20 mm, so that the total reductions of 50 + 40 + 10 100 mm and 40 + 40 + 20 100 mm, a jumper remains

19 mm i.e. vertically, its thickness is 13.4 mm. The slice is performed when the ingot is rotated and the workpiece enters the correct extension device, in which the ingot, whose axis is in the form of a screw, is straightened.

Claims (2)

SUMMARY OF THE INVENTION 1. A method for rolling rectangular billets, comprising a roll of an uneven width compression in the rolls of an initial billet, preferably a continuously cast ingot, with forming a billet and separating from the rest of the metal volume, characterized in that, in order to improve the quality of the metal, the compression is carried out from ft / R.1 two opposite surfaces of the original workpiece at angles of 45 ° to them. Moreover, the compression in each of the two zones of plastic deformation is one-sided. 2. A method according to claim 1, characterized in that the plastic deformation is carried out with the mutual displacement of the two deformation zones. Of Ot 17 Riga: 4 O.Z ft / t.5