Molding process of hot roll bending sharp-corner closed section steel

Abstract

The invention relates to a forming process for hot roll bending sharp-corner closed section steel, and aims to solve the problems of large residual stress at a bent corner part, serious work hardening, complex process, high cost and the like in an existing sharp-corner section steel cold-bending process. Roll bending forming is directly conducted through the high temperature of the hot-rolled steel plate, the four bent corners of the steel plate are machined in two sets, the first bent corner is finished into a sharp corner with the outer fillet radius close to zero after being formed, and then the second bent corner is formed and finished. The process comprises the steps of primary forming of a first bent angle, finishing of the first bent angle, primary forming of a second bent angle, fine forming, welding, welding seam cooling, finishing of the second bent angle, sizing, cooling, fixed-length cutting and the like. According to the process, the process is effectively shortened, the production cost is reduced, the quality of the sharp-corner profile steel is improved, particularly, the problem of residual stress in a corner area is solved, and the applicability of the sharp-corner profile steel applied to high-rise buildings is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of steel forming, and relates to a forming process of hot roll-bent sharp-angle closed-end steel. Background Art

[0002] The vigorous promotion and application of prefabricated structural buildings has led to an increasing demand for closed steel sections, especially square tubes. Conventional cold-formed closed steel sections have defects such as thinning in the fillet area, large fillet radius, and large residual stress, which have many limitations in their application in high-rise buildings. At the same time, if cold-formed sharp-angle steel sections are used, the corner area will be hardened by work, increasing the risk of cracking.

[0003] The existing method of forming sharp-angle steel is to first cold-bend and then heat the rounded corners for extrusion and sizing, or first cold-bend and then heat the whole part for extrusion and sizing. The process adds a heating step, which increases the cost of sharp-angle steel. At the same time, the sharp-angle steel formed in this way still has residual stress in the corner area, which still has limitations in its application in high-rise buildings. Summary of the invention

[0004] In view of this, the purpose of the present invention is to solve the above-mentioned problems and provide a forming process for hot roll-bent sharp-angle closed steel sections, which utilizes the high temperature of the steel plate after hot rolling to directly roll-bend the sharp-angle closed steel sections, shorten the process flow, reduce the cost of steel sections, and improve the product quality of sharp-angle steel sections.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A forming process of hot roll-bent sharp-angle closed steel, wherein four sharp corners of the sharp-angle closed steel are divided into two groups, namely, a first bend and a second bend, wherein the first bend is two bends on the outside of the unfolded steel plate, and the second bend is two bends on the inside of the unfolded steel plate. The sharp-angle closed steel is directly roll-bent by utilizing the high temperature of the hot-rolled steel plate. The roll-bending forming process comprises the following steps:

[0007] S1, the first bend is initially formed, the high temperature steel plate is subjected to hot roller forming of the two first bend portions to obtain a U-shaped open steel;

[0008] S2, first bend angle sharpening, finishing the first bend angle of the open steel section so that the first bend angle is formed into a sharp angle;

[0009] S3, initial forming of the second bend angle, forming the two second bend angle parts on the inner side of the high temperature steel plate;

[0010] S4, fine forming, further forming the first bend and the second bend of the open steel;

[0011] S5, welding, welding and fusing the closed position of the open steel section to form a closed steel section;

[0012] S6, welding seam cooling, welding seam cooling for closed steel;

[0013] S7, finishing the second bend corners, finishing and forming the two corresponding second bend corners on the closed steel into sharp corners;

[0014] S8, sizing, sizing the closed steel section and forming it into qualified products;

[0015] S9, cooling, cooling the closed steel after sizing;

[0016] S10, cutting to length, cutting the cooled steel sections to length;

[0017] S10, collecting and warehousing, collecting the finished steel sections to the finished product warehouse.

[0018] Furthermore, the angle of the first bend in S1 after initial forming is 85° to 92°.

[0019] Furthermore, in S2, the first bend of the open steel section is finished by using an inclined roller, so that the bend of the first bend after the initial forming is finished into a sharp corner with an outer fillet radius close to zero.

[0020] Furthermore, the angle of the second bend in S3 after initial forming is 65° to 75°.

[0021] Furthermore, in S7, a combination of flat and vertical rollers is used to finish the bend of the second bend in the closed steel section into a sharp corner with an outer fillet radius close to zero.

[0022] Optionally, the second bend corner sharpening process and the sizing process are performed simultaneously.

[0023] The beneficial effects of the present invention are:

[0024] The present invention effectively utilizes the deformation advantage of high temperature steel plate to realize the deformation of the bend of steel section into a sharp angle. The first bend is deformed to 85° to 92° in the initial forming stage, which is beneficial to the subsequent sharp angle finishing process and the fusion of the welded edges. The sharp angle finishing of the second bend is carried out simultaneously with the sizing process, which is beneficial to improving the forming efficiency.

[0025] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0027] Figure 1 It is a schematic diagram of the implementation process of the forming process of the hot roll bent sharp-angle closed steel section in the present invention.

[0028] Figure 2 Schematic diagram of the first corner tip finishing.

[0029] Figure 3 Schematic diagram of the second corner tip finishing.

[0030] Figure numerals: 1-high temperature steel plate; 11-first bend; 12-second bend; 21-open steel; 22-pointed open steel; 23-oblique roller. DETAILED DESCRIPTION

[0031] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and the features in the embodiments can be combined with each other without conflict.

[0032] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0033] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0034] See also Figures 1 to 3, which is a hot roll bending sharp angle closed steel forming process, the four sharp angles of the sharp angle closed steel are divided into two groups, namely the first angle 11 and the second angle 12, the first angle is the two angles on the outside of the steel plate after unfolding, and the second angle is the two angles on the inside of the steel plate after unfolding. The sharp angle closed steel is directly roll-bent by utilizing the high temperature of the steel plate after hot rolling; taking the hot roll bending square tube as an example, the "direct square forming" method is adopted for forming, and the roll bending forming process includes the following steps:

[0035] S1, first bend initial forming, hot roll forming of two first bends 11 of the high temperature steel plate 1, the angle of the first bend 11 after initial forming is 85° to 92°, and a U-shaped open steel 21 is obtained;

[0036] S2, finishing the first bend corner, finishing the first bend corner 11 of the open profile steel 21, using an inclined roller 23 to finish the first bend corner of the open profile steel 21, finishing the bend portion of the first bend corner after the initial forming into a sharp corner with an outer fillet radius close to zero, and obtaining a sharp-angle open profile steel 22;

[0037] S3, the second bend is initially formed, and the two second bends 12 on the inner side of the high temperature steel plate 1 are formed, and the angle of the second bend after the initial forming is 65° to 75°;

[0038] S4, fine forming, further forming the first bend corner and the second bend corner of the open steel 22;

[0039] S5, welding, using high frequency welding to weld and fuse the closed position of the open steel 22 to form a closed steel;

[0040] S6. Weld cooling: Use air cooling, water cooling or other methods to cool the weld of closed steel;

[0041] S7, finishing the sharp corners of the second bends, finishing and forming the two corresponding second bends on the closed steel into sharp corners, and using a combination of flat and vertical rollers to finish the bends of the second bends in the closed steel into sharp corners with an outer fillet radius close to zero;

[0042] S8, sizing, sizing the closed steel section and forming it into qualified products;

[0043] S9, cooling, cooling the closed steel after sizing;

[0044] S10, cutting to length, cutting the cooled steel sections to length;

[0045] S10, collecting and warehousing, collecting the finished steel sections to the finished product warehouse.

[0046] The sizing process is performed while the second bend corner is being refined.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A hot roll bending sharp angle closed steel forming process, characterized in that: The four sharp corners of the sharp-angle closed steel are divided into two groups, namely the first curved corner and the second curved corner. The first curved corners are the two curved corners on the outer side of the steel plate after unfolding, and the second curved corners are the two curved corners on the inner side of the steel plate after unfolding. The sharp-angle closed steel is directly roll-bent by utilizing the high temperature of the steel plate after hot rolling. The roll-bending process includes the following steps: S1, the first bend is initially formed, the high temperature steel plate is subjected to hot roller forming of the two first bend portions to obtain a U-shaped open steel; S2, first bend angle sharpening, finishing the first bend angle of the open steel section so that the first bend angle is formed into a sharp angle; S3, initial forming of the second bend angle, forming the two second bend angle parts on the inner side of the high temperature steel plate; S4, fine forming, further forming the first bend and the second bend of the open steel; S5, welding, welding and fusing the closed position of the open steel section to form a closed steel section; S6, welding seam cooling, welding seam cooling for closed steel; S7, finishing the second bend corners, finishing and forming the two corresponding second bend corners on the closed steel into sharp corners; S8, sizing, sizing the closed steel section and forming it into qualified products; S9, cooling, cooling the closed steel after sizing; S10, cutting to length, cutting the cooled steel sections to length; S10, collecting and warehousing, collecting the finished steel sections to the finished product warehouse.

2. The forming process of hot roll bending sharp angle closed steel according to claim 1 is characterized in that: The angle of the first bend in S1 after initial forming is 85° to 92°.

3. The forming process of hot roll bending angle closed steel according to claim 1 is characterized in that: In S2, the first bend of the open steel section is finished by using an inclined roller, and the bend of the first bend after the initial forming is finished into a sharp corner with an outer fillet radius close to zero.

4. The forming process of hot roll bending sharp angle closed steel according to claim 1 is characterized in that: The angle of the second bend in S3 after initial forming is 65° to 75°.

5. The forming process of hot roll bending sharp angle closed steel according to claim 1, characterized in that: In S7, a combination of flat and vertical rollers is used to finish the second bend of the closed steel section into a sharp corner with an outer corner radius close to zero.

6. The forming process of hot roll bending sharp angle closed steel according to claim 1, characterized in that: The second corner sharpness finishing process is carried out simultaneously with the sizing process.

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