RU2782330C1 - Rail rolling method - Google Patents

Abstract

FIELD: metal processing.

SUBSTANCE: invention relates to rolling rails. Sequential rolling is carried out in crimping stands for rolling rough profiles and a finishing continuous-reversible group of stands with the sequential use of box, T-shaped, closed split and open symmetrical calibers, two-roll control calibers of the auxiliary duo stand and three-roll calibers of universal reversible tandem stands of the said finishing continuous-reversible group, which form the rail base and rail. Rolling in the aforementioned universal reversible tandem stands is carried out in three-roll symmetrically arranged calibers. Compression of the rail head is carried out in a two-roll system with a slope of 6-8% calibers. Compression of the base of the rail is carried out in a three-roll system with the possibility of adjusting compression modes. Rolling in three-roll symmetrically arranged calibers is carried out simultaneously for two rail blanks in the symmetrical rolling mode.

EFFECT: as a result, it is possible to independently adjust the formation of the base of the rail and compensate for axial loads during rolling.

5 cl, 1 ex, 4 dwg

Description

The invention relates to rolling production, in particular to the production of I-sections.

Known "Method of rolling rails" [1] patent RU No. 2595082 (application No. 2015116829/02 of 30.04.2015, IPC B21 B 1/08, publ. 20.08.2016, bull. No. 23), which consists in the fact that rolling of asymmetric rail profiles in pre-finishing and finishing four-roll calibers, consisting of two horizontal drive rolls and two vertical non-drive rolls that form the sole and head of the rail, and the compression of the roll from the previous one in the subsequent caliber is carried out with equal rolling forces along the head and sole from the side of the vertical rolls .

Known "Method of rolling rails" [2] patent RU No. 2429090 (application No. 2010114609/02 MPK B21 1/08, publ. rolling of this roll in the finishing continuous-reversible group of tandem stands using universal four-roll, three-roll and auxiliary two-roll calibers, while the rough roll is set in the finishing group in tandem against the rolling progress on the mill and rolled in it in two passes, while in the first pass they use system of calibers: universal four-roll - auxiliary two-roll - universal four-roll - universal three-roll calibers.

Known "Method of rolling rails" [3] patent RU 2394660 (application No. 2008135537/02 dated 01.09.2008) IPC B21 B 1/08, publ. 07/20/2010, bul. No. 20), where the rolling of the rough profile is carried out in two-roll or universal rail passes, the rolling of the pre-finishing section is carried out in two-roll or three-roll passes, and the finishing section is rolled in two-roll, three-roll or four-roll passes with the final formation of the thickness of the neck and head in the streams of horizontal rolls, while the thickness the necks of the finishing gauge are formed taking into account the corresponding negative tolerance, and the thickness of the head of the finishing gauge, taking into account the corresponding plus tolerance.

Known "Method of rolling rails, a device for rolling rails and a rail made in this way" [4] patent RU No. 2530609 (application No. 2011141776/02 dated 08.03.2010) MPK3 V21V 1/085, publ. 10.10.2014, bul. No. 23), in which the manufacture of a rail blank containing a sole section, a head section and a neck section connecting the sole section with the head section, finishing rolling of the rail blank to form a steel rail in a multi-stand continuous tandem finishing mill containing at least three four-roll universal stands and at least two two-roll edger stands, wherein the universal stands comprise a vertical roll for forming the bottom section of the sole and a vertical roll for forming the section of the rail head, and two profiled horizontal rolls for forming the sides of the rail and, in particular, the section of the neck of the rail, while during the rolling process, the rail blank is passed through the finishing mill once, and at least the vertical rolls in all universal stands for forming the lower section of the sole are made in the form of smooth rolls, and at least one of the universal stands contains a smooth vertical roll for forming head area.

Known "Method of rolling rails" patent RU No. 2627140 [5] (application No. 2016139929 dated 10.10.2016) MPK3 V21V 1/08, publ. 08/03/2017, bul. No. 22), where rolling is carried out in roughing and finishing four-roll universal calibers with horizontal and vertical rolls, the latter of which are made with profile streams and shoulders on the side of the profile head, and in a pre-finishing open-type two-roll caliber, while rolling is carried out in a finishing four-roll caliber with a connector made on the side of the rail head between the shoulders of the vertical roll and the ends of the horizontal rolls in the areas of mating of the tread surface with the side surfaces of the rail head.

Known "Method of rolling rails" patent RU 2710410 [6] (application No. December 26, 2019, bul. No. 36), in which the manufacture of the original rail blank in duo-reversible stands, its further rolling in a continuously reversible group of stands in three passes, in which in the first and second passes the profile is formed in the following sequence: universal four-roll pass - auxiliary two-roll pass - a universal four-roll caliber, and in the third pass in the following sequence: a universal four-roll caliber - an auxiliary two-roll caliber - a finishing universal three-roll caliber, while the horizontal rolls of the universal four-roll and finishing three-roll calibers are performed with slopes to the vertical of the side faces that form the inner edges of the flanges of the sole of the profile , characterized in that in the third pass, the profile is additionally formed in the pre-finishing universal four-roll caliber according to the scheme, which includes the following sequence: universal four-roll caliber - auxiliary d Vukh-roll caliber - pre-finishing universal four-roll caliber - finishing universal three-roll caliber, while the value of the slopes of the side faces of the horizontal rolls of the universal four-roll calibers, including the pre-finishing one, is 1.14-1.30 of the slope of the corresponding side faces of the horizontal rolls of the finishing universal three-roll caliber .

The disadvantages of all of the above methods is the presence of four-roll calibers, which limits the possibility of arranging the second balancing caliber, three-roll symmetrically located calibers for rolling two rails simultaneously. Also, on the bandage itself, the force on the sinus towards the sole and towards the head will not be uniform, because. in the horizontal direction, the profile is asymmetric, which can create a condition for the displacement of the bandage.

The closest (prototype) in terms of technical essence to the claimed method, in terms of the number of similar features, is the "Method of rolling rails" patent RU No. 03/19/2020, bul. No. 8) [7], where sequential rolling is carried out in one or two rough reversible duo stands and a finishing continuous-reversible group of stands with the sequential use of box, tee, closed split and open balancing passes, two-roll control passes of the auxiliary duo stand, four-roll and three-roll calibers of universal stands of the finishing group, while rolling in the rough reversible stands duo is completed after rolling in closed split calibers, while balancing with simultaneous control of the height of the flanges of the intermediate section is carried out in a two-roll open pass of severe deformation in the auxiliary stand duo of the finishing continuous-reversible group of stands.

The disadvantage of this method is that it is not possible to simultaneously roll two rail blanks in symmetrical calibers, compensating for axial loads on the rolls, taking the mode as symmetrical rolling.

The technical result, to which the proposed invention is directed, is an increase in the productivity of rail rolling operations due to the location of the second three-roll symmetrical caliber, which makes it possible to simultaneously roll two rail blanks, as well as to independently adjust the formation of the rail sole, as an element that requires the greatest expansion.

The specified technical result is ensured due to the fact that in the method of rolling rails, including sequential rolling in one or two rough reversing stands of a duo and a finishing continuous-reversing group of stands with the sequential use of box, tee, closed split and open balancing calibers, two-roll control calibers of the auxiliary stand duo, and three-roll calibers of universal stands of tandem finishing group, the following differences are provided:

- rolling in universal reversible stands is carried out in three-roll symmetrically arranged calibers, due to which it becomes possible to locate two symmetrical calibers in each stand and roll two rail blanks simultaneously;

- compression in the head is carried out according to a two-roll system with a slope of calibers of 6-8%, this angle will ensure the occupancy of the caliber along the rail head;

- compression in the sole is carried out according to a three-roll system, with the possibility of setting the mode of compression of the sole;

- rolling in symmetrical calibers is carried out simultaneously by two rail blanks according to the symmetrical rolling mode, which compensates for axial loads on the rolls and eliminates the axial displacement of the bandage.

In addition, in the finishing and in the auxiliary (edger) stand, the reduction is carried out in a three-roll mode, while the rail blank is placed horizontally with a head connector strictly along the profile symmetry axis, and after reduction in the simultaneously two rail blanks.

In addition, after reduction in the reduction stand, two rail blanks are simultaneously transferred to the tandem stand group.

In addition, after compression in the crimping stand, one rail blank is cut across into two equal parts, while one part of the rail blank is turned over, after which two parts of the rail blank are simultaneously set into a group of tandem stands.

In addition, after reduction in the reduction stand, one rail blank is issued, and their rolling is carried out in any of two paired symmetrical paired three-roll calibers.

The essence of the invention is illustrated by drawings, where:

On FIG. 1 shows the layout of the working stands of a typical rail and beam mill, which consists of a reversing swaging stand duo I, a roughing stand duo II, a continuous-reversing tandem group, including universally reversible four-roll stands III and V, an auxiliary stand duo IV and a universal four-roll irreversible stand VI.

On FIG. 2 shows the layout of balancing passes in the stands of the tandem group and in the finishing stand shown in Fig. one.

On FIG. Figure 3 shows the scheme of billet rolling in a group of tandem stands and in a finishing stand with balancing passes in 3 passes.

On FIG. 4 shows the scheme of billet rolling in a group of tandem stands and in a finishing stand with balancing passes in 5 passes.

The essence of the proposed method is as follows:

After rolling in the crushing stand I (FIG. 1) and the roughing stand II (FIG. 1), a rough rail profile is obtained, which is transferred during rolling to the tandem finishing group consisting of 2 universal reversible four-roll stands III and V and an auxiliary stand duo IV (FIG. 1, FIG. 2), while allowing two options: The first option is the presence of two crimping stands, for issuing two draft profiles simultaneously. The second option is to roll one rail blank, and then it is cut across into two equal parts, where one part of the rail blank is turned over symmetrically to the second part, for their further transfer to a tandem group, where the profile is rolled in three passes (1, 2, 3 - FIG. 3), or in 5 passes (1, 2, 3, 4, 5 - FIG. 4). After reduction in the reduction stand, one billet is issued, and their rolling is carried out in any of two paired symmetrical three-roll calibers. The peculiarity of the formation of the rail profile is that for each rail in the universal stands, a three-roll rolling scheme is used, and the formation of the sole is controlled by adjusting the position of the vertical roll, with possible preload along the thickness of the sole. The formation of the rail head is carried out by means of two horizontal drive rolls, the lateral compression is carried out by bringing the rolls together, and the compression along the height of the head is carried out by placing the rail in the groove at a slope of 6-8%, this angle will ensure the filling of the gauge along the rail head, and due to reduction of the gap along the thickness of the neck in the process of bringing together horizontal rolls. At the same time, in the first and second reversible universal stands, the slope of the balancing gauge is made at a mutually opposite angle III, V (FIG. 2.), and the connector on the head side has a closed part on opposite sides (top-bottom), which ensures the sequence of the compression heads from the upper and lower shafts, aligning the tension difference, which ensures the uniformity of the formation of the rail head for the task in the next gauge (for the auxiliary stand) and the symmetry of the finished profile (for the finishing stand). In the finishing stand, the reduction is carried out in a three-roll mode, while the rail is placed horizontally with a head connector strictly along the profile symmetry axis.

An example of the implementation of the method

The proposed rail rolling method is planned to be implemented on the universal rail and beam mill of EVRAZ Nizhny Tagil Metallurgical Plant JSC in the production of R65 type rails 25 m long.

Rail steel was smelted in a 160 t converter and poured into a billet with a section of 300 × 360 mm on a CCM. The resulting blanks were heated to a temperature of 1180÷1270°C and rolled in duo-reversible stands BD1 and BD2 for 10 passes into a draft rail profile with dimensions of 199×36×106/193,

where 199 is the width of the sole, mm;

36 - neck thickness, mm;

106 - head width, mm;

193 - rail height.

The resulting roll was transferred to a continuously reversible group of stands and rolled in three passes, where in the first pass the profile is formed sequentially in a universal three-roll, auxiliary two-roll, universal three-roll calibers, in the second pass in a universal three-roll and auxiliary two-roll caliber, and the third pass was carried out according to the scheme in universal three-roll, auxiliary two-roll and then - finishing universal three-roll caliber (FIG.3) in a stand-alone stand VI (FIG.1, 2).

The technical and economic effect of the method for the production of a hot-rolled I-beam is:

- rolling of two blanks at the same time, with the possibility of increasing the productivity of the stands of the tandem group;

- obtaining conditionally symmetrical rolling, with compensation of axial loads;

- the possibility of independent adjustment of the degree of deformation in the base of the rail (in contrast to two-roll rolling);

- the possibility of separate and alternate rolling of two billets in each caliber separately.

Sources of information

[1] Patent No. RU 2595082 (application No. 2015116829/02 dated April 30, 2015) “Method of rolling rails” IPC B21V 1/08, publ. 08/20/2016, bul. No. 23.

[2] Patent No. RU 2429090 (application No. 2010114609/02) "Method of rolling rails" MPK3 B21 1/08, publ. 09/20/2011, bul. No. 30.

[3] Patent No. RU 2394660 (application No. 2008135537/02 dated 09/01/2008) "Method of rolling rails" MPK3 V21V 1/08, publ. 07/20/2010, bul. No. 20.

[4] Patent No. RU 2530609 (application No. 2011141776/02 dated 08.03.2010) “Method of rolling rails, a device for rolling rails and a rail manufactured by this method” MPK3 V21V 1/085, publ. 10.10.2014, bul. No. 23.

[5] Patent No. RU 2627140 (application No. 2016139929 dated October 10, 2016) “Method of rolling rails” MPK3 V21V 1/08, publ. 08/03/2017, bul. No. 22.

[6] Patent No. RU 2710410 (application No. 2019114014 dated May 6, 2019) “Method of rolling rails” MPK3 V21V 1/08, publ. December 26, 2019, bul. No. 36.

[7] Patent No. RU 2717251 (application No. 2019104911 dated February 21, 2019) “Method of rolling rails” MPK3 V21V 1/08, publ. 03/19/2020, bul. No. 8.

Claims (5)

1. The method of rolling rails, which includes sequential rolling in one or two swaging stands for rolling rough profiles and a finishing continuous-reversing group of stands with the successive use of box, tee, closed split and open balancing calibers, two-roll control calibers of the auxiliary duo stand and three-roll universal calibers tandem reversible stands of the mentioned finishing continuous-reversing group, which form the base and the rail head, characterized in that the rolling in the mentioned universal reversible tandem stands is carried out in three-roll symmetrically arranged calibers, while the rail head is reduced in a two-roll system with a caliber slope of 6- 8% to ensure the fillability of the caliber along the rail head, and the compression of the sole is carried out in a three-roll system with the ability to adjust the compression modes, and rolling in three-roll symmetrically arranged calibers is carried out simultaneously but for two rail blanks in the symmetrical rolling mode to compensate for the axial load on the rolls. 2. The method according to claim 1, characterized in that in the finishing continuous-reversible group of stands, the reduction is carried out in a three-roll system with the rail blank horizontally with a head connector strictly along the profile symmetry axis. 3. The method according to claim 1, characterized in that after reduction in one or two reduction stands, two rail blanks are simultaneously transferred to the universal reversible tandem stands. 4. The method according to claim 3, characterized in that after compression in the crimping stand of one rail blank, it is cut across into two equal parts, while one part is turned over, after which the two parts of the rail blank are set simultaneously in the universal reversible tandem stands. 5. The method according to claim 1, characterized in that after reduction in the reduction stand, one billet is issued, and their rolling is carried out in one of two paired symmetrical three-roll calibers.

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