A large-specification hot-rolled h-shaped steel with equal flange-web thickness and a production method thereof

Abstract

A kind of flange web equal-thickness large-specification hot-rolled H-shaped steel and its production method, belong to H-shaped steel rolling technical field, the production method of this hot-rolled H-shaped steel, successively including converter smelting, shaped billet continuous casting, billet heating, blooming rolling, universal rolling and air cooling production procedure, the blooming pass used in blooming rolling includes two flange deformation zones and the web deformation zone between them, the middle part of the web deformation zone is outwardly convex, the beneficial effects of the present application are that, the present application can produce flange web equal-thickness large-specification hot-rolled H-shaped steel, avoid the thickness fluctuation and pitted surface and other defects caused by metal transition loss in the process of rolling, can satisfy the demand of not use application scene.

Description

Technical Field

[0001] This invention relates to the field of H-beam rolling technology, and in particular to a hot-rolled H-beam of large dimensions with equal thickness of flanges and web, and its production method. Background Technology

[0002] Using shaped billets to roll hot-rolled H-beams reduces rolling passes and improves production efficiency compared to using slabs and rectangular billets. However, the number of possible cross-sectional dimension combinations for shaped billets is significantly less than that for finished hot-rolled H-beams. This results in some finished product specifications experiencing surface and dimensional quality issues due to poor matching between flange and web dimensions and the shaped billet. This is especially true when producing "large height + large width + equal flange and web thickness," where the web is prone to large dimensional fluctuations and severe surface pitting, hindering the widespread application of related products.

[0003] In the field of steel structure construction, vertical members require hot-rolled H-beams with a large cross-sectional area, and specifications with flanges and webs of nearly equal thickness are a good choice. As the application scenarios expand to ultra-large and ultra-high steel structures, the thickness of flanges and webs also increases. Hot-rolled H-beams with the characteristics of "large height + large width + equal thickness of flanges and webs" have good market potential.

[0004] For example, patent CN116037644A provides a method for simultaneously thinning the flanges and webs of high-height hot-rolled H-beams with heights of 400mm-700mm and flange thicknesses of less than 20mm, and heights of 900mm-1100mm and flange thicknesses of less than 30mm. By adjusting the reduction rate of the flanges and webs in each pass of the universal rolling stage and matching the diameters of the horizontal and vertical rolls, the method achieves simultaneous thinning of the flanges and webs of high-height hot-rolled H-beams. This method requires simultaneous deformation coordination of the flanges and webs in the universal rolling stage, and further compression of the web thickness in the billet-opening stage. When producing large-diameter hot-rolled H-beams with equal flange and web thicknesses, web quality problems become more severe. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a large-size hot-rolled H-beam with a flange thickness to web thickness ratio of 0.9 to 1.1 and a method for producing the same.

[0006] To achieve the above objectives, the technical solution adopted by the present invention to solve its technical problem is: the large-size hot-rolled H-beam with equal thickness of flange and web includes a web and flanges, wherein the thickness ratio of the web to the flange is 0.9 ≤ T. w / T f ≤1.1, the web height H is 600~1200mm, and the flange width B is 300~500mm.

[0007] The thickness T of the web wThe thickness T of the flange is 20–100 mm. f It ranges from 20 to 100 mm.

[0008] A method for producing large-sized hot-rolled H-beams with equal flange and web thickness includes the following production steps: converter smelting, continuous casting of shaped billets, billet heating, billet rolling, universal rolling, and air cooling. The billet rolling uses a billet pass that includes two flange deformation zones and a web deformation zone between them, with the middle of the web deformation zone being convex.

[0009] The cross-section of the web deformation zone is set to be elliptical, and the web deformation zone and the flange deformation zone are smoothly connected.

[0010] After the initial rolling process, the web of the rolled piece is formed by outward convexity on both the upper and lower sides of the middle part of the web, forming an outward convex web section.

[0011] The cross-section of the convex web segment is set to an ellipse, and the convexity h of the convex web segment is... t The flange thickness T of the formed H-beam f Web thickness T w The relationship between them is h t =(20.5-2.3×T) f / T w +T w / 9-T f / 7)~(21.5-2.3×T f / T w +T w / 9-T f / 7).

[0012] The billet rolling process employs either multi-hole or single-hole forming.

[0013] In the universal rolling process, the flange of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness.

[0014] At the start of universal rolling, the horizontal rolls of the universal mill are a distance away from the web of the workpiece. In the last pass, the horizontal rolls press down the web of the workpiece to the target thickness in one pass.

[0015] The beneficial effects of this invention are:

[0016] This invention provides a large-size hot-rolled H-beam with equal flange and web thickness and its production method. In the initial rolling stage, a rolled piece with an approximately elliptical web cross-section is formed, with the web bulging outward in the middle and thinnest at the inner rounded corner where it meets the flange. In the universal rolling stage, the flange thickness is compressed in each pass until the target thickness of the finished product is reached. For the web, it is only controlled in the last pass to reach the target thickness of the finished product. During the universal rolling process, the longitudinal extension formed by the flange thickness compression will stretch the web. From the cross-section, the web metal will flow towards the flange, and the closer to the middle of the web, the more obvious the effect of the longitudinal deformation and the greater the transverse flow velocity of the metal, resulting in a reduction in the web thickness of the rolled piece. The metal bulging outward in the middle of the rolled piece will participate in the flow first, avoiding thickness fluctuations and surface defects in the web caused by metal transition loss. Attached Figure Description

[0017] The following is a brief explanation of the contents of each of the accompanying drawings and the markings in the drawings:

[0018] Figure 1 This is a schematic diagram of the hot-rolled H-beam blanking pattern of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the hot-rolled H-beam of the present invention;

[0020] Figure 3 This is a schematic diagram of the structure of the hot-rolled H-beam of the present invention;

[0021] The markings in the above figures are: 1. Flange deformation zone, 2. Web deformation zone, 3. Outwardly convex web segment. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0023] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "wide flange", "narrow flange", "thin web", "thick web", "both sides", "both sides", "excessive extension", etc. are merely descriptive differences and do not specifically refer to specific dimensions, positions or deformations, and therefore should not be construed as limitations on this invention.

[0025] This invention provides a large-size hot-rolled H-beam with equal thickness of flange and web, comprising a web and flanges, wherein the thickness ratio of the web to the flange is 0.9≤T. w / T f ≤1.1, web height H is 600~1200mm, flange width B is 300~500mm. Web thickness T w The flange thickness T is 20–100 mm. f It ranges from 20 to 100 mm.

[0026] If H is less than 600mm, rolling a shaped billet would involve vertical rolling passes, increasing the thickness of the rolled piece, making the production method of this invention unnecessary. If H is greater than 1200mm, the initial rolling stage involves significant widening rolling passes, resulting in a large difference between the web thickness and flange thickness of the rolled piece, making the production method of this invention unsuitable. Therefore, the range of H is 600mm to 1200mm.

[0027] If B is less than 300mm, the lateral stiffness of the vertical component is low, limiting its application scenarios and reducing the number of applications required. If B is greater than 500mm, the flange width of the irregular billet is large, significantly increasing the difficulty of continuous casting production, which existing equipment cannot support. Therefore, the range of B is 300mm to 500mm.

[0028] Such as T w For thicknesses less than 20mm, increasing the web thickness has limited effect on improving the load-bearing capacity of vertical members; for example, T... w If the diameter is greater than 100 mm, the rolled piece cannot form the approximately elliptical cross-section required by the method of this invention, resulting in insufficient convexity. Therefore, T w The range is 20mm to 100mm.

[0029] Such as T f For diameters less than 20mm, the required cross-sectional area for vertical components is smaller; for example, T f For flanges thicker than 100mm, the economic benefits of increasing lateral and longitudinal stiffness are poor, and this approach is generally not adopted. Therefore, T f The range is 20mm to 100mm.

[0030] This invention also provides a method for producing large-sized hot-rolled H-beams with equal thickness of flanges and webs, comprising the following production steps in sequence: converter smelting, continuous casting of shaped billets, billet heating, billet rolling, universal rolling, and air cooling. Of course, depending on the requirements of product mechanical properties, process properties, composition design, etc., molten iron pretreatment can be performed before converter smelting, argon blowing refining, ladle refining, and vacuum refining can be performed sequentially between converter smelting and continuous casting of shaped billets, and post-rolling controlled cooling can be performed between universal rolling and air cooling.

[0031] In the initial rolling process, the mill arrangement is either reciprocating or continuous. To avoid defects such as thickness fluctuations and roughness in the web due to metal transition losses, the initial rolling pass is adjusted. Specifically, the initial rolling pass includes two flange deformation zones 1 and a web deformation zone 2 between them. The web deformation zone 2 has a convex center and an elliptical cross-section. The web deformation zone 2 and flange deformation zone 1 are smoothly connected. After the initial rolling is completed, the web of the finished piece has convex upper and lower sides forming convex web segments 3, with an elliptical cross-section. During universal rolling, the longitudinal extension caused by the compression of the flange thickness will stretch the web. From the cross-section, the web metal will flow towards the flange, and the closer to the middle of the web, the more obvious the effect of the rigid end of the longitudinal deformation, and the greater the transverse flow velocity of the metal, resulting in a reduction in the web thickness of the rolled piece. Meanwhile, the metal that bulges outward in the middle of the rolled piece will participate in the flow first. Therefore, defects such as thickness fluctuation and pitting caused by metal transition loss in the web are avoided.

[0032] The initial rolling process can be either multi-hole or single-hole forming, depending on the specific process.

[0033] In the universal rolling process, the flanges of the workpiece are rolled in multiple passes. During the final pass, the flanges are compressed to the target thickness while the web is simultaneously pressed down to the target thickness. Specifically, at the beginning of universal rolling, the horizontal rolls of the universal mill are spaced a distance from the web of the workpiece. In the final pass, the horizontal rolls press down the web to the target thickness in one pass. By reserving web metal in the workpiece, when the flanges are compressed relatively more during universal rolling, the metal transition loss caused by the lateral flow of web metal can be compensated, avoiding defects such as web thickness fluctuations and rough surfaces. Therefore, it is possible to produce hot-rolled H-beams with a flange-to-web thickness ratio of 0.9–1.1, a maximum height of 1200 mm, a maximum width of 500 mm, and a maximum web and flange thickness of 100 mm. The specifications applicable to this method are wide-ranging, and the produced products can meet the needs of various application scenarios.

[0034] Specifically, the convexity h of the convex web segment 3 is... t The convexity h is the distance along the flange width direction between the outermost part of the convex web segment 3 and the end of the convex web segment 3.t This refers to the convexity of the web deformation zone 2 of the blanking hole, and this convexity h t The flange thickness T of the formed H-beam f Web thickness T w The relationship between them is h t =(20.5-2.3×T) f / T w +T w / 9-T f / 7)~(21.5-2.3×T f / T w +T w / 9-T f / 7). The design of the convexity range of the web of the rolled piece can effectively compensate for the metal transition loss caused by the lateral flow of web metal when the flange reduction is relatively large during the universal rolling stage, and effectively avoid defects such as web thickness fluctuation and pitting.

[0035] The following examples illustrate the production methods of hot-rolled H-beams of different sizes and specifications.

[0036] Example 1

[0037] As shown in Table 1, the desired cross-sectional dimensions of the hot-rolled H-beam are: web height H = 600 mm, flange width B = 300 mm, and web thickness T = 0. w It is 20mm, and the flange thickness T f The calculated flange to web thickness ratio T is 20mm. f / T w It is 1.0.

[0038] The above-mentioned production method for hot-rolled H-beams includes converter smelting, continuous casting of shaped billets, billet heating, roughing rolling, universal rolling, and air cooling. The roughing roll pass crown is 17.6 mm. The cross-sectional dimensions of the rolled piece after roughing rolling are: height Hb = 760 mm, width Bb = 308 mm, flange thickness tfb = 105 mm, and crown h of the convex web section 3. t The thickness is 17.6 mm, and the thickness twb at the end of the convex web section 3 is 80 mm.

[0039] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0040] Batch measurements and statistics were performed on the hot-rolled H-beams obtained by the production method of this invention, and the average cross-sectional dimensions were as follows: web height H = 600 mm, flange width B = 300 mm, and web thickness T = 0.5 mm. w It is 19.8 mm, and the flange thickness Tf The diameter is 20.0 mm, and the dimensional tolerance meets the process requirements.

[0041] Example 2

[0042] As shown in Table 1, the difference from Example 1 is that the convexity of the blank roll is 18.1 mm.

[0043] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0044] Batch measurements and statistics were performed on the hot-rolled H-beams obtained by the production method of this invention, and the average cross-sectional dimensions were as follows: web height H = 600 mm, flange width B = 301 mm, and web thickness T = 0.5 mm. w It is 20.0 mm, and the flange thickness T f The diameter is 20.1 mm, and the dimensional tolerance meets the process requirements.

[0045] Example 3

[0046] As shown in Table 1, the difference from Example 1 is that the convexity of the blank roll is 18.5 mm.

[0047] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0048] Batch measurements and statistics were performed on the hot-rolled H-beams produced by the method of this invention, and the average cross-sectional dimensions obtained were as follows: web height H = 599 mm, flange width B = 300 mm, and web thickness T = 0.5 mm. w It is 20.0 mm, and the flange thickness T f The diameter is 19.9mm, and the dimensional tolerance meets the process requirements.

[0049] Example 4

[0050] As shown in Table 1, the desired cross-sectional dimensions of the hot-rolled H-beam are: web height H = 700 mm, flange width B = 300 mm, and web thickness T = 100 mm. w It is 30mm, and the flange thickness T f The calculated flange to web thickness ratio T is 30mm. f / T w It is 1.0.

[0051] The above-mentioned production method for hot-rolled H-beams includes converter smelting, continuous casting of shaped billets, billet heating, rough rolling, universal rolling, and air cooling. The rough rolling pass crown is 17.7 mm. The cross-sectional dimensions of the rolled piece after rough rolling are: height Hb = 840 mm, width Bb = 310 mm, flange thickness tfb = 105 mm, and crown h of the convex web section 3. t The thickness is 17.7 mm, and the thickness twb at the end of the convex web section 3 is 85 mm.

[0052] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0053] Batch measurements and statistics were performed on the hot-rolled H-beams obtained by the production method of this invention, and the average cross-sectional dimensions were as follows: web height H = 701 mm, flange width B = 300 mm, and web thickness T = 100 mm. w It is 29.8 mm, and the flange thickness T f The diameter is 30.1mm, and the dimensional tolerance meets the process requirements.

[0054] Example 5

[0055] As shown in Table 1, the desired cross-sectional dimensions of the hot-rolled H-beam are: web height H = 800 mm, flange width B = 400 mm, and web thickness T = 100 mm. w It is 40mm, and the flange thickness T f The calculated flange to web thickness ratio T is 40mm. f / T w It is 1.0.

[0056] The above-mentioned production method for hot-rolled H-beams includes converter smelting, continuous casting of shaped billets, billet heating, rough rolling, universal rolling, and air cooling. The rough rolling pass crown is 17.4 mm. The cross-sectional dimensions of the rolled piece after rough rolling are: height Hb = 1040 mm, width Bb = 412 mm, flange thickness tfb = 165 mm, and crown h of the convex web section 3. t The thickness is 17.4 mm, and the thickness twb at the end of the convex web section 3 is 90 mm.

[0057] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0058] Batch measurements and statistics were performed on the hot-rolled H-beams obtained by the production method of this invention, and the average cross-sectional dimensions were as follows: web height H = 800 mm, flange width B = 401 mm, and web thickness T = 0.5 mm.w It is 39.9 mm thick, and the flange thickness T is... f The diameter is 40.0 mm, and the dimensional tolerance meets the process requirements.

[0059] Example 6

[0060] As shown in Table 1, the desired cross-sectional dimensions of the hot-rolled H-beam are: web height H = 900 mm, flange width B = 300 mm, and web thickness T = 0. w It is 50mm, and the flange thickness T f The calculated flange to web thickness ratio T is 55mm. f / T w It is 1.1.

[0061] The above-mentioned production method for hot-rolled H-beams includes converter smelting, continuous casting of shaped billets, billet heating, roughing rolling, universal rolling, and air cooling. The roughing roll pass crown is 16.2 mm. The cross-sectional dimensions of the rolled piece after roughing rolling are: height Hb = 990 mm, width Bb = 311 mm, flange thickness tfb = 105 mm, and crown h of the convex web section 3. t The thickness is 16.2 mm, and the thickness twb at the end of the convex web section 3 is 90 mm.

[0062] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0063] Batch measurements and statistics were performed on the hot-rolled H-beams obtained by the production method of this invention, and the average cross-sectional dimensions were as follows: web height H = 900 mm, flange width B = 300 mm, and web thickness T = 0. w It is 50.0 mm, and the flange thickness T f The diameter is 54.8mm, and the dimensional tolerance meets the process requirements.

[0064] Example 7

[0065] As shown in Table 1, the desired cross-sectional dimensions of the hot-rolled H-beam are: web height H = 1000 mm, flange width B = 400 mm, and web thickness T = 1000 mm. w It is 75mm, and the flange thickness T f The calculated flange to web thickness ratio T is 70mm. f / T w It is 0.9.

[0066] The above-mentioned production method for hot-rolled H-beams includes converter smelting, continuous casting of shaped billets, billet heating, roughing rolling, universal rolling, and air cooling. The roughing roll pass crown is 17.2 mm. The cross-sectional dimensions of the rolled piece after roughing rolling are: height Hb = 1280 mm, width Bb = 413 mm, flange thickness tfb = 215 mm, and crown h of the convex web section 3. t The thickness is 17.2 mm, and the thickness twb at the end of the convex web section 3 is 100 mm.

[0067] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0068] Batch measurements and statistics were performed on the hot-rolled H-beams produced by the method of this invention, and the average cross-sectional dimensions obtained were as follows: web height H = 999 mm, flange width B = 400 mm, and web thickness T = 0.5 mm. w It is 74.7 mm thick, and the flange thickness T is... f The diameter is 70.0 mm, and the dimensional tolerance meets the process requirements.

[0069] Example 8

[0070] As shown in Table 1, the desired cross-sectional dimensions of the hot-rolled H-beam are: web height H = 1050 mm, flange width B = 500 mm, and web thickness T = 1050 mm. w It is 70mm, and the flange thickness T f The calculated flange to web thickness ratio T is 70mm. f / T w It is 1.0.

[0071] The above-mentioned production method for hot-rolled H-beams includes converter smelting, continuous casting of shaped billets, billet heating, rough rolling, universal rolling, and air cooling. The rough rolling pass crown is 16.5 mm. The cross-sectional dimensions of the rolled piece after rough rolling are: height Hb = 1330 mm, width Bb = 511 mm, flange thickness tfb = 215 mm, and crown h of the convex web section 3. t The thickness is 16.5mm, and the thickness twb at the end of the convex web section 3 is 95mm.

[0072] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0073] Batch measurements and statistics were performed on the hot-rolled H-beams obtained by the production method of this invention, and the average cross-sectional dimensions were as follows: web height H = 1050 mm, flange width B = 500 mm, and web thickness T = 1050 mm. w It is 70.1 mm, and the flange thickness T f The diameter is 69.9mm, and the dimensional tolerance meets the process requirements.

[0074] Example 9

[0075] As shown in Table 1, the desired cross-sectional dimensions of the hot-rolled H-beam are: web height H = 1100 mm, flange width B = 400 mm, and web thickness T = 1100 mm. w It is 80mm, and the flange thickness T f The calculated flange to web thickness ratio T is 80mm. f / T w It is 1.0.

[0076] The above-mentioned production method for hot-rolled H-beams includes converter smelting, continuous casting of shaped billets, billet heating, rough rolling, universal rolling, and air cooling. The rough rolling pass crown is 16.2 mm. The cross-sectional dimensions of the rolled piece after rough rolling are: height Hb = 1360 mm, width Bb = 412 mm, flange thickness tfb = 215 mm, and crown h of the convex web section 3. t The thickness is 16.2 mm, and the thickness twb at the end of the convex web section 3 is 105 mm.

[0077] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0078] Batch measurements and statistics were performed on the hot-rolled H-beams obtained by the production method of this invention, and the average cross-sectional dimensions were as follows: web height H = 1099 mm, flange width B = 399 mm, and web thickness T = 1099 mm. w It is 80.2 mm, and the flange thickness T f The diameter is 80.3mm, and the dimensional tolerance meets the process requirements.

[0079] Example 10

[0080] As shown in Table 1, the desired cross-sectional dimensions of the hot-rolled H-beam are: web height H = 1150 mm, flange width B = 500 mm, and web thickness T = 1150 mm. w It is 80mm, and the flange thickness T f The calculated flange to web thickness ratio T is 90mm. f / T w It is 1.1.

[0081] The above-mentioned production method for hot-rolled H-beams includes converter smelting, continuous casting of shaped billets, billet heating, rough rolling, universal rolling, and air cooling. The rough rolling pass crown is 14.4 mm. The cross-sectional dimensions of the rolled piece after rough rolling are: height Hb = 1390 mm, width Bb = 514 mm, flange thickness tfb = 215 mm, and crown h of the convex web section 3. t The thickness is 14.4 mm, and the thickness twb at the end of the convex web section 3 is 110 mm.

[0082] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0083] Batch measurements and statistics were performed on the hot-rolled H-beams obtained by the production method of this invention, and the average cross-sectional dimensions were as follows: web height H = 1150 mm, flange width B = 499 mm, and web thickness T = 1150 mm. w It is 80.1 mm, and the flange thickness T f The diameter is 90.1 mm, and the dimensional tolerance meets the process requirements.

[0084] Example 11

[0085] As shown in Table 1, the desired cross-sectional dimensions of the hot-rolled H-beam are: web height H = 1200 mm, flange width B = 500 mm, and web thickness T = 1200 mm. w It is 100mm, and the flange thickness T f Given a flange thickness of 100mm, the calculated flange-to-web thickness ratio T f / T w It is 1.0.

[0086] The above-mentioned production method for hot-rolled H-beams includes converter smelting, continuous casting of shaped billets, billet heating, roughing rolling, universal rolling, and air cooling. The roughing roll pass crown is 15.5 mm. The cross-sectional dimensions of the rolled piece after roughing rolling are: height Hb = 1420 mm, width Bb = 515 mm, flange thickness tfb = 215 mm, and crown h of the convex web section 3. t The thickness is 15.5mm, and the thickness twb at the end of the convex web section 3 is 115mm.

[0087] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0088] Batch measurements and statistics were performed on the hot-rolled H-beams obtained by the production method of this invention, and the average cross-sectional dimensions were as follows: web height H = 1200 mm, flange width B = 500 mm, and web thickness T = 1200 mm. w The flange thickness is 100.0 mm, and the flange thickness is T. f The diameter is 100.1 mm, and the dimensional tolerance meets the process requirements.

[0089] Comparative Example 1

[0090] As shown in Table 1, the cross-sectional dimensions of the rolled piece formed after the initial rolling process differ from those in Example 1 in that the initial roll pass convexity is 5.0 mm.

[0091] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0092] Batch measurements and statistics of hot-rolled H-beams obtained by the production method of this invention show that the web of the hot-rolled H-beams has severe pitting defects and excessive thickness reduction, which does not meet the processing requirements.

[0093] Comparative Example 2

[0094] As shown in Table 1, the cross-sectional dimensions of the rolled piece formed after the initial rolling process differ from those in Example 1 in that the initial roll pass convexity is 25.0 mm.

[0095] In the universal rolling process, the flange plate of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

[0096] Batch measurements and statistics of hot-rolled H-beams produced by the production method of this invention revealed that the web of the hot-rolled H-beams near the flanges exhibited a through-bar folding defect, which did not meet the processing requirements.

[0097] Table 1. Production requirements, roll dimensions, and relevant dimensional parameters of hot-rolled H-beams in the examples and comparative cases.

[0098]

[0099] From the above embodiments and comparative examples, it can be concluded that the convexity h of the blanking die... t It meets the requirements within the set range (20.5-2.3×T). f / T w +T w / 9-T f / 7)~(21.5-2.3×T f / T w +Tw / 9-T f When using the universal rolling method of the present invention, hot-rolled H-beams that meet the processing requirements can be obtained.

[0100] In summary, this invention utilizes existing equipment and irregularly shaped billets, modifies the billet pass shape, and forms a rolled piece with an approximately elliptical cross-section of the web during the billet rolling stage. During the universal rolling stage, the flange thickness is compressed to the target thickness in each pass, with the web thickness controlled to the target thickness only in the final pass. By reserving web metal in the rolled piece, when the flange is compressed relatively heavily during the universal rolling stage, the metal transition loss caused by the lateral flow of web metal is compensated, avoiding defects such as web thickness fluctuations and pitting. This invention can produce hot-rolled H-beams with a flange thickness to web thickness ratio of 0.9–1.1, a maximum height of 1200 mm, a maximum width of 500 mm, and a maximum web and flange thickness of 100 mm. The method has a wide range of applicable specifications, and the produced products can meet the needs of different application scenarios.

[0101] The above description is merely an illustration of some principles of the present invention. This specification is not intended to limit the present invention to the specific structures and applicable scope shown. Therefore, all possible modifications and equivalents that may be used fall within the scope of the patent application of this invention.

Claims

1. A method for producing large-sized hot-rolled H-beams with equal flange and web thickness, comprising the following steps in sequence: converter smelting, continuous casting of shaped billets, billet heating, roughing rolling, universal rolling, and air cooling; wherein the roughing rolling uses a roughing pass pattern including two flange deformation zones and a web deformation zone between them, characterized in that... Large-diameter hot-rolled H-beams with equal thickness of web and flanges include a web and flanges, wherein the thickness ratio of the web to the flange is 0.9≤T. w / T f ≤1.1, the web height H is 600~1200mm, the flange width B is 300~500mm; the web deformation zone is convex in the middle; In the universal rolling process, the flange of the workpiece is rolled in multiple passes. When the last pass is rolled, the flange of the workpiece is compressed to the target thickness, and at the same time the web of the workpiece is pressed down to the target thickness in one pass.

2. The method for producing large-diameter hot-rolled H-beams with equal flange and web thickness according to claim 1, characterized in that: The thickness T of the web w The thickness T of the flange is 20~100mm. f The diameter is 20~100mm.

3. The method for producing large-diameter hot-rolled H-beams with equal flange and web thickness according to claim 1, characterized in that: The cross-section of the web deformation zone is set to be elliptical, and the web deformation zone and the flange deformation zone are smoothly connected.

4. The method for producing large-diameter hot-rolled H-beams with equal flange and web thickness according to claim 3, characterized in that: After the initial rolling process, the web of the rolled piece is formed by outward convexity on both the upper and lower sides of the middle part of the web, forming an outward convex web section.

5. The method for producing large-diameter hot-rolled H-beams with equal flange and web thickness according to claim 4, characterized in that: The cross-section of the convex web segment is set to an ellipse, and the convexity h of the convex web segment is... t The flange thickness T of the formed H-beam f Web thickness T w The relationship between them is h t = (20.5 - 2.3 × T) f / T w + T w / 9 - T f / 7)~(21.5 - 2.3 × T f / T w + T w / 9 - T f / 7).

6. The method for producing large-diameter hot-rolled H-beams with equal flange and web thickness according to claim 1, characterized in that: The billet rolling process employs either multi-hole or single-hole forming.

7. The method for producing large-diameter hot-rolled H-beams with equal flange and web thickness according to claim 1, characterized in that: At the start of universal rolling, the horizontal rolls of the universal mill are a distance away from the web of the workpiece. In the last pass, the horizontal rolls press down the web of the workpiece to the target thickness in one pass.

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