A method for blooming I-shaped steel rails

Abstract

The present invention discloses a method for blooming I-shaped rails, which includes changing the method of distributing metal by using hat-shaped pass and adopting the method of distributing metal by using I-shaped pass. The billet first undergoes head and bottom metal distribution, and then is compressed to form a rail-shaped billet. After meeting the initial dimensions, it is rolled in the I-shaped roughing pass to form a billet for universal rolling.

Description

Technical Field

[0001] The present invention relates to a method for blooming I-shaped rails. Background Art

[0002] Conventional blooming pass for rails generally adopts a cap-shaped pass, which can be divided into single-cap or multi-cap types. The blank is first compressed and then the cap-shaped pass is used to distribute the metal of the rail head and rail bottom, and then the rail-shaped pass is used for rough rolling. The sidewall slope of the cap pass is small, which makes it difficult to restore the pass after wear, and the depth-cut wedge wears and ages seriously, increasing the pit defects on the rail bottom surface. Summary of the Invention

[0003] In order to solve the above technical problems, the object of the present invention is to provide a method for blooming I-shaped rails, which essentially adopts a method of distributing metal by using an I-shaped pass.

[0004] To solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The present invention is a method for blooming I-shaped rails, which includes changing the method of distributing metal by the traditional cap-shaped pass that first compresses and then distributes, and adopting a method of distributing metal by using an I-shaped pass. The blank is first subjected to head-bottom metal distribution, and then compressed to form a rail-shaped blank. After meeting the initial dimensions, it is rolled in the rail-shaped roughing pass to form a blank for universal rolling.

[0006] Further, the specific process steps include: square billet - pre-cut groove - vertical rolling - cutting groove - vertical rolling - depth-cut forming pass - control pass - feeding pass - finishing raw material. After blooming rolling, the rolled piece becomes an asymmetrical I-shape with large ends and a thin middle.

[0007] Further, the rectangular blank is heated to the required temperature, descaled, and then pre-cut in the K1 pass to become a pre-cut pass rolled piece. After being flipped 90 degrees, it enters the K2 pass for compression to become a vertical rolling pass rolled piece. Then it is flipped 90 degrees again and enters the K3 pass for multi-pass rolling to become a cutting groove pass rolled piece. After being flipped 90 degrees, vertical rolling is carried out to control the rail height to become a vertical rolling control pass rolled piece, completing the deformation in the rough rolling stage. After being flipped 90 degrees, it enters the K5 and K6 roughing passes in sequence for secondary depth-cutting, reducing the rail bottom thickness and the thickness of the waist and head, respectively becoming a depth-cut pass rolled piece and a control pass rolled piece. The control pass rolled piece finally enters the K7 pass to regularize the dimensions of each part, forming an intermediate blank with the shape and dimensions required for universal rolling.

[0008] Compared with the prior art, the beneficial technical effects of the present invention are:

[0009] 1. By adopting the pre-cut groove technology, the steel billet is first divided into head, waist, and bottom regions by utilizing the characteristics of easy deformation at high temperature;

[0010] 2. The asymmetric I-shaped deep-cut pass structure is adopted for sectional rolling of the head, web, and base, further distributing the metal in each area of the head, web, and base.

[0011] 3. The vertical pass is used to control the height of the rail billet, flexibly controlling the reduction amount to obtain the required dimensions.

[0012] 4. All cogging passes adopt an open pass structure for shallow groove rolling to avoid the use of large roll ring rolls. Brief Description of the Drawings

[0013] The present invention will be further described below in conjunction with the drawings.

[0014] Figure 1 It is the pass setting diagram of the I-shaped cogging method for rails of the present invention;

[0015] Figure 2 It is the schematic diagram of different rolled piece shapes after being processed by different passes;

[0016] Description of the reference numerals in the drawings: 1, billet; 2, rolled piece of the pre-cut pass; 3, rolled piece of the vertical pass; 4, rolled piece of the grooving pass; 5, rolled piece of the vertical pressure control pass; 6, rolled piece of the deep-cut pass; 7, rolled piece of the control pass; 8, rolled piece of the intermediate billet pass.

[0017] K1 - pre-cut pass; K2 - vertical pass; K3 - grooving pass; K4 - vertical pressure control pass; K5 - deep-cut pass; K6 - control pass; K7 - intermediate billet pass. Detailed Embodiment

[0018] An I-shaped cogging method for rails, according to the metal deformation principle, changes the method of distributing metal in the cap-shaped pass, and adopts the I-shaped pass to distribute metal. The billet first conducts head and base metal distribution, and then is compressed to form a rail-shaped billet. After meeting the initial dimensions, it is rolled into a billet for universal rolling in the I-shaped roughing pass. The process includes: square billet - pre-cut groove - vertical pressure - grooving - vertical rolling - deep-cut forming pass - control pass - feeding pass - finishing raw material (intermediate billet). After starting rolling, the rolled piece becomes an I-shaped with large ends and a thin middle, so it is called the I-shaped cogging method.

[0019] The specific steps are as follows: The rectangular billet 1 is heated to the required temperature, and after descaling, it is pre-deep-cut in the K1 pass to become a shaped rolled piece 2, then flipped 90 degrees and enters the K2 pass for compression to become the rolled piece 3, then flipped 90 degrees again and enters the K3 pass for multi-pass rolling to become a rail-shaped rolled piece 4, flipped 90 degrees for vertical rolling to control the height of the rail to become the rolled piece 5, completing the deformation in the initial rolling stage. Then it is flipped 90 degrees and successively enters the K5 and K6 roughing passes for secondary deep-cutting to reduce the thickness of the rail base and the thickness of the web and head. Finally, it enters the K7 pass to regularize the dimensions of each part to form an intermediate billet with the shape and dimensions required for universal rolling.

[0020] The present invention has the following characteristics:

[0021] 1. By adopting the pre-cutting groove technology, the steel billet is divided into head, waist and bottom regions first by utilizing the characteristics of high-temperature easy deformation.

[0022] 2. By adopting an asymmetric I-shaped cutting depth pass structure for sectional rolling of the head, waist and bottom, the metal in each region is further distributed.

[0023] 3. By using a vertical rolling pass to control the height of the rail billet, the reduction is flexibly controlled to obtain the required dimensions.

[0024] 4. All blooming passes adopt an open pass structure for shallow groove rolling to avoid the use of large roll ring rolls.

[0025] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for blooming an I-shaped rail, characterized in that: A method for distributing metal by changing the hat-shaped pass is adopted, and a method for distributing metal by using the I-shaped pass is used. The billet first undergoes head and bottom metal distribution and then is compressed to form an I-shaped billet. After meeting the initial dimensions, it is rolled in the I-shaped roughing pass to form a billet for universal rolling. The specific process steps include: square billet - pre-cutting groove - vertical rolling - cutting groove - vertical rolling - depth-cutting forming pass - sizing pass - feeding pass - finishing raw material. After blooming rolling, the rolled piece becomes an I-shaped with large ends and a thin middle. The rectangular billet (1) is heated to the required temperature, descaled, and then undergoes pre-depth cutting in the K1 pass to become the pre-cut pass rolled piece (2). After being flipped 90 degrees, it enters the K2 pass for compression to become the vertical rolling pass rolled piece (3). Then it is flipped 90 degrees again and rolled in multiple passes in the K3 pass to become the grooved pass rolled piece (4). After being flipped 90 degrees for vertical rolling to control the rail height, it becomes the vertical rolling sizing pass rolled piece (5), completing the deformation in the blooming stage. After being flipped 90 degrees, it enters the K5 and K6 roughing passes in sequence for secondary depth cutting to reduce the rail bottom thickness and the web and head thickness, respectively becoming the depth-cut pass rolled piece (6) and the sizing pass rolled piece (7). The sizing pass rolled piece (7) finally enters the K7 pass to regularize the dimensions of each part, forming the intermediate billet (8) with the shape and dimensions required for universal rolling.

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