A novel process for straightening the bent flanges of wide-flange H-beams using a pressure straightening machine

Abstract

This invention discloses a novel process for straightening the flange bending of wide-flange H-beams using a pressure straightening machine, relating to the field of wide-flange H-beam production technology. It addresses the problem of poor straightening effect of pressure straightening on the X-leg H-beams. This invention employs a horizontal pressure straightening machine, with a main pressure head applying pressure and an anvil providing support on either side of the roller conveyor. The X-leg H-beam to be straightened is placed on the roller conveyor with its height direction parallel to the pressure direction. Based on the flange width of the H-beam to be straightened, another pressure-applying H-beam is selected and placed between the main pressure head of the pressure straightening machine and the H-beam to be straightened. The pressure from the main pressure head is transmitted to the H-beam to be straightened through the pressure-applying H-beam. This invention requires no additional equipment, and no increase in process time, energy consumption, or labor costs. The implementation process is simple, convenient, safe, efficient, and yields a high success rate.

Description

Technical Field

[0001] This invention relates to the field of wide-flange H-beam production technology, specifically a novel process for straightening bent flanges of wide-flange H-beams using a pressure straightening machine. Background Technology

[0002] HW (wide flange) H-beams are a key product of Maanshan Iron & Steel's Long Products Division's first heavy H-beam production line in China. The wide flange H-beam production line uses SFC (Steam-Flanged Flange Cooling) and QST (Quick-Steam Cooling) processes for post-rolling cooling. However, due to varying cooling rates in different parts of the rolled piece, the initial flange curvature varies significantly after the wide flange rolled piece is placed on the cooling bed, making it impossible to straighten the initial flange curvature along its entire length. Furthermore, some specifications in certain series suffer from incomplete flange straightening due to insufficient UF vertical roll reduction, frequently resulting in flange curvature forming X-legs. These problems prevent the rolled product from meeting national standards and user requirements. Therefore, to address the flange curvature issue, the production process initially attempted to straighten the curved flanges using a roller straightener. However, roller straighteners have a straightening blind zone, and the section modulus of the wide flange rolled piece exceeds the capacity of the online roller straightener, also preventing straightening. Therefore, a horizontal pressure straightener is now being tested in production.

[0003] Horizontal pressure straighteners are commonly used to straighten vertical bends in rolled products and lateral bends in wide-flange rolled products. According to the national standard GB / T11263-2017, steel with flange bends is classified into several types, including inward and outward expansion of the flange. These types of flange bends are mainly concentrated in high-flange and wide-flange rolled products, with X-shaped outward expansion of the flange being the most common problem. Usually, high-flange rolled products can be straightened by directly applying pressure to one side of the X-shaped flange using the pressure straightener head. However, when straightening wide-flange rolled products with a pressure straightener, the stress point is at the flange during the straightening process. Direct pressure from the main pressure head can cause the flange to bend into a strip-like shape, forming a lotus leaf shape, or it may cause the web of the rolled product to bulge, resulting in scrap. Therefore, the straightening process for X-shaped flange bends in wide-web steel using pressure straighteners needs improvement. Summary of the Invention

[0004] The purpose of this invention is to provide a novel process for straightening the flange bending of wide-flange H-beams using a pressure straightening machine, in order to solve the problem of poor straightening effect of pressure straightening on the X-legs of the steel being straightened.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a novel process for straightening the flange bending of wide-flange H-beams using a pressure straightening machine, employing a horizontal pressure straightening machine, with a main pressure head applying pressure and an anvil providing support on both sides of the roller table. The H-beam to be straightened is placed on the roller table with its height direction parallel to the pressure direction. Based on the flange width of the H-beam to be straightened, another H-beam for applying pressure is selected and placed between the main pressure head of the pressure straightening machine and the H-beam to be straightened. The pressure from the main pressure head is transmitted to the H-beam to be straightened through the pressure-applying H-beam.

[0006] Preferably, based on the flange width of the X-leg H-beam to be straightened, another supporting H-beam is selected, and the supporting H-beam is placed between the anvil and the H-beam to be straightened.

[0007] Preferably, the height direction of the H-beams for pressurization and the H-beams for support is parallel or perpendicular to the pressure direction.

[0008] Preferably, if the height direction of the H-beam for pressurization or the H-beam for support is parallel to the pressure direction, its flange width is not less than the flange width of the H-beam to be straightened; if the height direction of the H-beam for pressurization or the H-beam for support is perpendicular to the pressure direction, its height corresponds to the flange width of the H-beam to be straightened.

[0009] Preferably, after the H-beam to be straightened is straightened, its flange bending value reaches the standard range.

[0010] Preferably, the main pressure head parameters of the horizontal pressure straightener are set according to the flange bending value of the H-beam to be straightened.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] This novel pressure straightening machine technology for straightening the flange bending of wide-flange H-beams utilizes pressure-applying and support H-beams for force transmission and support. It can effectively straighten wide-flange H-beams with X-legs without causing defects such as machine damage, flared edges, or web bulging to the H-beams being straightened. This effectively improves the product yield and solves the quality problem of flange bending and X-leg exceeding tolerances. In addition, this technology does not require the addition of new equipment, nor does it increase the cost of process time, energy consumption, or labor. Moreover, the implementation process is simple, convenient, safe, and efficient, making it suitable for direct application based on existing technologies. Attached Figure Description

[0013] Figure 1 This is a structural schematic diagram of an X-leg wide-flange H-beam, where H is the height of the beam, B is the flange width, b is half of B, and F is the flange bending value.

[0014] Figure 2 This is a straightening schematic diagram of one embodiment of the present invention, where F represents the pressure direction. Detailed Implementation

[0015] A novel process for straightening the flange bending of wide-flange H-beams using a pressure straightening machine is disclosed. The machine employs a horizontal pressure straightening machine with a main pressure head applying pressure and an anvil providing support on both sides of the roller conveyor. The H-beam to be straightened is placed on the roller conveyor with its height direction parallel to the pressure direction. Based on the flange width of the H-beam to be straightened, another H-beam for applying pressure is selected and placed between the main pressure head of the pressure straightening machine and the H-beam to be straightened. The pressure from the main pressure head is transmitted to the H-beam to be straightened through the pressure-applying H-beam.

[0016] See Figure 2 In a preferred embodiment, another supporting H-beam can be selected based on the flange width of the H-beam to be straightened, and the supporting H-beam can be placed between the anvil and the H-beam to be straightened.

[0017] The aforementioned H-beams for pressure application and support can be placed parallel or perpendicular to the pressure direction in terms of height. If the height direction of the H-beams for pressure application or support is parallel to the pressure direction, their flange width shall not be less than the flange width of the H-beam to be straightened. If the height direction of the H-beams for pressure application or support is perpendicular to the pressure direction, their height shall correspond to the flange width of the H-beam to be straightened. (See also...) Figure 2 The diagram shows three H-beams. The middle one is the H-beam to be straightened. The one on the left is the supporting H-beam, placed parallel to the pressure direction in its height direction. Its flange width is greater than that of the H-beam to be straightened, ensuring contact with the upper and lower ends of the X-leg flange until straightening is complete. Similarly, the one on the right is the pressurizing H-beam, placed perpendicular to the pressure direction in its height direction. Its height is equal to or slightly greater than the flange width of the H-beam to be straightened, but the height of the pressurizing H-beam minus the flange thickness must be less than the flange width of the H-beam to be straightened. This is also to ensure contact as much as possible and prevent incomplete straightening or defects.

[0018] After the H-beams to be straightened are straightened, their flange bending values ​​can reach the standard range. For example, for wide-flange H-beams with a flange width B≦400mm, the flange bending value F≦1.5%b and F≦1.5mm is considered to meet the standard. The specific value can be determined according to industry standards or product requirements.

[0019] The main pressure head parameters of the horizontal pressure straightener are set according to the flange bending value of the H-beam to be straightened, and the setting method is the same as that of general straightening.

[0020] Example:

[0021] Using the process method described in the above embodiments, six groups of H-beams to be straightened were straightened. The specific parameters and results are shown in Table 1 below. In the table, H in the straightening method indicates that the height direction is parallel to the pressure direction, and I indicates that it is perpendicular.

[0022] Table 1: Process parameters and straightening effect of the main pressure head for H-beams to be straightened (unit / mm)

[0023] H-beams to be straightened H-beams for pressure application and support Straightening methods Precorrected F-value feed rate Pressure Correction Course Post-correction F-value 1 344*348*10*16 365*322*26.9*44.1 H+X+H 2.5-3.0 6 232 0.8-1.2 2 344*348*10*16 365*322*26.9*44.1 H+X+I 2.0-2.5 5 274 0.5-0.8 3 344*348*10*16 365*322*26.9*44.1 I+X+I 1.5-2.0 4 316 0.6 4 388*402*15*15 436.6*412.2*35.8*58 H+X+H 2.8-3.5 8 46.8 0.8-1.0 5 388*402*15*15 436.6*412.2*35.8*58 H+X+I 2.0-2.5 7 70.2 0.5-0.8 6 388*402*15*15 436.6*412.2*35.8*58 I+X+I 1.5-2.0 6 93.6 0.5

[0024] In the table above, the flange bending value F of each group of X-leg wide-flange H-beams met the standard after straightening. In addition, before May 2022, the yield of 344*348*10*16 specification was 79.5%. After adopting the process method in the above implementation method in August, the yield of this specification reached 87.3%. The reason is that the X-leg straightening effect is good and the defects after straightening are few, which will not lead to the bulging of the flange and web.

[0025] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

[0026] Any aspects of this invention not described in detail are well-known to those skilled in the art.

Claims

1. A novel process for straightening the flange bending of wide-flange H-beams using a pressure straightening machine, comprising a horizontal pressure straightening machine, with a main pressure head applying pressure and an anvil providing support on both sides of the roller conveyor, wherein the H-beam to be straightened is placed on the roller conveyor with its height direction parallel to the pressure direction, characterized in that... The process includes the following: according to the flange width of the H-beam to be straightened, another H-beam for pressurization is selected and placed between the main pressure head of the pressure straightening machine and the H-beam to be straightened. The pressure of the main pressure head is transmitted to the H-beam to be straightened through the pressurized H-beam. Based on the flange width of the X-leg H-beam to be straightened, select another supporting H-beam and place the supporting H-beam between the anvil and the H-beam to be straightened. The height direction of the H-beams used for pressurization and the H-beams used for support is parallel or perpendicular to the pressure direction. If the height direction of the H-beam for pressure application or the H-beam for support is parallel to the pressure direction, its flange width shall not be less than the flange width of the H-beam to be straightened; if the height direction of the H-beam for pressure application or the H-beam for support is perpendicular to the pressure direction, its height shall correspond to the flange width of the H-beam to be straightened.

2. The novel process for straightening the flange bending of wide-flange H-beams using a pressure straightening machine according to claim 1, characterized in that: After the H-beam to be straightened is straightened, its flange bending value reaches the standard range.

3. The novel process for straightening the bent flanges of wide-flange H-beams using a pressure straightening machine according to claim 1, characterized in that: The main pressure head parameters of the horizontal pressure straightener are set according to the flange bending value of the H-beam to be straightened.

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