A method for designing a pass for bar superior steel and common steel mixed production

Abstract

The application discloses a kind of bar excellent steel and general steel mixed production pass design method, it is related to bar rolling process technical field, including based on national standard positive tolerance design excellent steel pass base circle radius, based on negative tolerance design general steel pass base circle radius, the difference of two base circle radius is 0.15~0.25mm;Excellent steel, general steel pass is integrated in different grooves of same roller, maximum distribution number is adjusted according to specification dynamically, and groove is distributed according to yield proportion;By adjusting expansion radius, roll gap precision and outside corner radius, the size precision of excellent steel is promoted to two groups or more from national standard three groups.The application is under the architecture of low-cost two-roller mill, considers excellent steel high-precision rolling and general steel negative difference maximization production, applicable to Φ20~45mm round steel mixed production line, solves the technical problem that precision and yield rate are difficult to coordinate optimization in traditional process.

Description

Technical Field

[0001] This invention relates to the field of bar rolling technology, and in particular to a method for designing a pass profile for the mixed production of high-quality steel and ordinary steel bars. Background Technology

[0002] In the field of steel rolling technology, bar production lines are widely used to produce two types of products: ordinary carbon round steel (ordinary steel) and high-quality round steel (premium steel). In existing technologies, conventional two-roll mills use a single finished product pass system, with the same pass used for both ordinary and premium steel rolling. However, this approach has significant drawbacks: insufficient dimensional accuracy: when producing premium steel, it can only meet the minimum accuracy requirements of national standards (such as the third set of national standard accuracy), failing to meet the high-precision demands of high-end customers; limited negative tolerance rolling: when producing ordinary steel, because the pass design is not optimized for negative tolerances, the potential for increasing yield is limited, making it difficult to maximize negative tolerance rolling; high equipment costs: some high-end enterprises use three-roll or four-roll reducing and sizing mills to improve accuracy, but the equipment investment and maintenance costs are high, making it difficult to promote on small and medium-sized production lines.

[0003] In addition, the existing single-pass rolling mill system lacks flexible configuration capabilities and cannot dynamically adjust the rolling mill resources according to the production demand of high-quality steel and ordinary steel, resulting in low capacity utilization and inability to flexibly allocate according to the production ratio, which further restricts production efficiency.

[0004] Therefore, how to optimize the pass design under a low-cost two-roll mill architecture to simultaneously achieve high-precision rolling of premium steel and maximize negative tolerance of ordinary steel, while improving the dynamic allocation efficiency of rolling slot resources, has become an urgent technical problem to be solved. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for designing rolling pass profiles in the mixed production of high-quality and ordinary steel bars. Through differentiated pass profile design, roll integration, and dynamic slot adjustment, this invention achieves high-precision rolling and improved yield.

[0006] To achieve the above objectives, the present invention provides a method for die design in the production of bar stock made from a mixture of high-quality steel and ordinary steel, comprising the following steps:

[0007] S1. For round steel bars with diameters from Φ20mm to Φ45mm, design finished die patterns for high-quality steel and ordinary steel respectively, wherein:

[0008] The base circle radius of the finished die for high-quality steel is designed based on the upper limit of the positive tolerance of the national standard, while the base circle radius of the finished die for ordinary steel is designed based on the lower limit of the negative tolerance of the national standard.

[0009] The difference in base circle radius between high-quality steel and ordinary steel is 0.15mm to 0.25mm, and the difference in groove width is 0.1mm to 0.3mm.

[0010] S2. The finished steel die and the finished steel die are machined into different grooves of the same roll, and the maximum number of grooves of the roll is dynamically adjusted according to the specifications.

[0011] S3. Based on the total output of a single batch and the steel throughput per slot, allocate the number of rolling slots according to the ratio of high-quality steel to ordinary steel output, wherein:

[0012] For specifications of Φ20mm~Φ28mm, the maximum number of slots is 12~15;

[0013] For specifications of Φ30mm~Φ45mm, the maximum number of slots is 8~12;

[0014] S4. Based on the measured ellipticity and dimensional parameters of the finished product during the rolling process, the expansion radius, roll gap, and outer corner radius of the high-quality steel roll and the ordinary steel roll are optimized and iterated until the ellipticity of the high-quality steel is ≤0.3mm and the dimensional accuracy reaches or exceeds the national standard group II.

[0015] Furthermore, in step S1, the expansion radius of the finished die of the high-quality steel is set to 20mm to 28mm, and the expansion radius of the finished die of the ordinary steel is set to 23mm to 31mm. The expansion angle of the high-quality steel and the ordinary steel is set to 30° or 35° according to the specifications, and the difference between the expansion angle of the high-quality steel and the ordinary steel under the same specifications does not exceed 5°.

[0016] Furthermore, the dynamic adjustment rule for the number of grooves on the rolls is as follows:

[0017] For every 5mm increase in size, the maximum number of grooves decreases by 1 to 2. Specifically, Φ20mm corresponds to 15 grooves, and Φ45mm corresponds to 8 grooves. Furthermore, the number of grooves decreases in a stepwise manner as the size increases.

[0018] Furthermore, the rule for configuring the number of rolling grooves in step S3 is as follows:

[0019] Let the total number of holes and slots be N. 总 The planned output of ordinary steel accounts for P%, and the planned output of high-quality steel accounts for Y%, satisfying the condition that P% + Y% = 100%;

[0020] Number of holes and slots in ordinary steel = round(N) 总 ×P%);

[0021] Number of holes and slots in high-quality steel = N 总 - Number of holes and slots in ordinary steel.

[0022] Furthermore, the difference in base circle radius in step S1 is dynamically adjusted according to specifications:

[0023] The difference in base circle radius between Φ20mm high-quality steel and ordinary steel is 0.15mm, and the difference for Φ45mm steel is 0.25mm. The difference increases linearly with the increase of the specification.

[0024] Furthermore, the roll processing in step S2 is carried out in stages. The initial roll profile parameters are set based on theoretical calculations. The expansion radius is corrected and the outer corner radius is optimized according to the actual rolling size data. The correction range does not exceed 5% of the original parameter value.

[0025] Furthermore, the method covers a range of round steel specifications from Φ20mm to Φ45mm, and the die parameters for high-quality steel and ordinary steel are stored and retrieved separately through independent process procedures.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1. The present invention provides a die design method for the mixed production of high-quality steel and ordinary steel bars. Through differentiated die design, the dimensional accuracy of the high-quality steel finished product is improved from the national standard three groups to the national standard two groups, and some specifications can reach the accuracy of one group, which meets the needs of high-end customers for high-precision round steel.

[0028] 2. The present invention provides a method for designing the rolling pass for the mixed production of high-quality steel and ordinary steel bars. Based on the negative tolerance design of the finished ordinary steel rolling pass, the negative tolerance rolling is maximized, the overall yield of ordinary steel is improved, and the raw material cost is significantly reduced per batch.

[0029] 3. The present invention provides a method for designing the roll pass for mixed production of high-quality steel and ordinary steel bars. The number of grooves on the same roll is dynamically allocated according to the production ratio of high-quality steel and ordinary steel, thereby reducing the number of roll changes, improving roll utilization and production efficiency, and reducing equipment operation and maintenance costs. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a flowchart illustrating a method for designing the pass profile in the production of bar stock using a mixture of high-quality steel and ordinary steel, as described in an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the ordinary steel die pattern in a method for producing high-quality steel bars by mixing ordinary steel and bar stock according to an embodiment of the present invention.

[0033] Figure 3 This is a schematic diagram of the high-quality steel die design method for the mixed production of high-quality steel and ordinary steel in an embodiment of the present invention. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0037] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0038] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0039] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0040] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0041] Example 1

[0042] like Figures 1 to 3 As shown, this invention provides a method for designing the pass profile in the production of bar stock made from a mixture of high-quality steel and ordinary steel, comprising the following steps:

[0043] S1. For round steel bars with specifications ranging from Φ20mm to Φ45mm, including Φ20mm, Φ22mm, Φ25mm, Φ28mm, Φ30mm, Φ32mm, Φ35mm, Φ36mm, Φ38mm, Φ40mm, Φ42mm, and Φ45mm, respectively, design finished die patterns for high-quality steel and ordinary steel, where:

[0044] As shown in Table 1, the base circle radius of the finished die of high-quality steel is designed based on the upper limit of the positive tolerance of the national standard, and the base circle radius of the finished die of ordinary steel is designed based on the lower limit of the negative tolerance of the national standard.

[0045] The difference in base circle radius between high-quality steel and ordinary steel is 0.15mm to 0.25mm, and the difference in groove width is 0.1mm to 0.3mm. For example, the difference is 0.15mm for Φ20mm and 0.25mm for Φ45mm. The difference increases linearly with the increase of the specification.

[0046] S2. The finished steel profile and the finished steel profile are machined into different grooves of the same roll. The maximum number of grooves on the roll is dynamically adjusted according to the specifications. For every 5mm increase in specifications, the maximum number of grooves decreases by 1 to 2. For example, Φ20mm corresponds to 15 grooves and Φ45mm corresponds to 8 grooves. The number of grooves decreases in a stepwise manner as the specifications increase.

[0047] S3. Based on the total output of a single batch and the steel throughput per slot, allocate the number of rolling slots according to the ratio of high-quality steel to ordinary steel output, wherein:

[0048] For specifications of Φ20mm~Φ28mm, the maximum number of slots is 12~15;

[0049] For specifications of Φ30mm~Φ45mm, the maximum number of slots is 8~12;

[0050] Let the total number of holes and slots be N. 总 N 总 As determined by Table 2, the planned output of ordinary steel accounts for P%, and the planned output of high-quality steel accounts for Y%, and the ratio of P% to Y% is equal to 100%.

[0051] Then the number of holes and slots in ordinary steel = round(N) 总 ×P%);

[0052] Number of holes and slots in high-quality steel = N 总 -Number of holes and slots in ordinary steel.

[0053] S4. Measure the dimensions of finished products in real time. Based on the measured ellipticity and dimensional parameters of the finished products during the rolling process, optimize and iterate the expansion radius, roll gap, and outer corner radius of the high-quality steel roll pass and the ordinary steel roll pass until the ellipticity of the high-quality steel is ≤0.3mm and the dimensional accuracy reaches or exceeds the national standard group II.

[0054] Correction for expansion radius: Corrected in reverse according to the measured size, with the correction range ≤ 5% of the original parameter value;

[0055] Roll gap adjustment: The roll gap of ordinary steel of the same specification is equal to that of high-quality steel;

[0056] Adjustment of outer corner radius: Depending on the base circle radius and actual production conditions, the outer corner radius of high-quality steel of different specifications may be reduced or increased by 0.1 to 0.5 mm or equal to that of ordinary steel.

[0057] Furthermore, in step S1, the expansion radius of the finished die of the high-quality steel is set to 20mm to 28mm, and the expansion radius of the finished die of the ordinary steel is set to 23mm to 31mm. The expansion angle of the high-quality steel and the ordinary steel is set to 30° or 35° according to the specifications, and the difference between the expansion angle of the high-quality steel and the ordinary steel under the same specifications does not exceed 5°.

[0058] Furthermore, the difference in base circle radius in step S1 is dynamically adjusted according to specifications:

[0059] The difference in base circle radius between Φ20mm high-quality steel and ordinary steel is 0.15mm, and the difference for Φ45mm steel is 0.25mm. The difference increases linearly with the increase of the specification.

[0060] Furthermore, the roll processing in step S2 is carried out in stages. The initial roll profile parameters are set based on theoretical calculations. The expansion radius is corrected and the outer corner radius is optimized according to the actual rolling size data. The correction range does not exceed 5% of the original parameter value.

[0061] Furthermore, the method covers a range of round steel specifications from Φ20mm to Φ45mm, and the die parameters for high-quality steel and ordinary steel are stored and retrieved separately through independent process procedures.

[0062] Example 2

[0063] Based on the method of Example 1, the Φ22mm specification is used as the specification in this example;

[0064] S1, High-quality steel and ordinary steel finished product die patterns are designed independently.

[0065] Base circle radius design: Ordinary steel base circle radius: 10.90mm (lower limit of negative tolerance in national standard), high-quality steel base circle radius: 11.05mm (upper limit of positive tolerance in national standard), base circle radius difference: 0.15mm;

[0066] Groove width difference: Ordinary steel groove width: 22.6mm, high-quality steel groove width: 22.8mm, groove width difference: 0.2mm;

[0067] Expansion angle: 30° for both ordinary steel and high-quality steel;

[0068] Expansion radius: 26.2mm for ordinary steel, 23mm for high-quality steel;

[0069] Roll gap: The roll gap for both ordinary steel and high-quality steel is 3.0 mm;

[0070] Outer corner radius: 0.3mm for ordinary steel, 0.6mm for high-quality steel.

[0071] S2 and S3, mixed processing of rolls and dynamic adjustment of grooves

[0072] The Φ22mm high-quality steel and ordinary steel pass profiles are machined into different grooves on the same roll. According to Table 2, the maximum number of grooves is determined to be 15. For example, the planned output of ordinary steel accounts for 55% and high-quality steel accounts for 45%. Therefore, the number of grooves for ordinary steel is 8 and the number of grooves for high-quality steel is 7.

[0073] S4. Parameter Optimization and Adjustment

[0074] In the initial parameters, the expansion radius of ordinary steel is 26.2 mm, the expansion radius of high-quality steel is 23 mm, and the measured ellipticity of high-quality steel is 0.35 mm, which exceeds the target value by 0.3 mm.

[0075] Adjust the parameters:

[0076] For ordinary steel, the expansion radius is 25mm, and the correction range is -1.2mm, ≤5% of the original value;

[0077] The expansion radius of the high-quality steel is 22mm, with a correction range of -1.0mm, ≤5% of the original value;

[0078] Roll gap adjustment: The roll gap for both ordinary steel and high-quality steel is 3.0mm;

[0079] Optimization of outer corner radius: The outer corner radius of high-quality steel is reduced to 0.3mm, while that of ordinary steel remains at 0.3mm.

[0080] After optimization, the ellipticity of the high-quality steel was reduced to 0.25mm, and the dimensional accuracy reached the national standard group II.

[0081] The optimized Φ22mm parameters are archived as "Excellent Round 22" and "Ordinary Round 22" respectively.

[0082] Example 3

[0083] Based on the method of Example 1, the Φ28mm specification is used as the specification in this example;

[0084] S1, High-quality steel and ordinary steel finished product die patterns are designed independently.

[0085] Base circle radius design: Ordinary steel base circle radius: 13.90mm (national standard negative tolerance lower limit), high-quality steel base circle radius: 14.15mm (national standard positive tolerance upper limit), base circle radius difference: 0.25mm;

[0086] Groove width difference: Ordinary steel groove width: 28.6mm, high-quality steel groove width: 29.13mm, groove width difference: 0.53mm;

[0087] Expansion angle: 35° for ordinary steel and 30° for high-quality steel, a difference of 5°;

[0088] Expansion radius: 21.27mm for ordinary steel, 26mm for high-quality steel;

[0089] Roll gap: 4.0mm for ordinary steel, 3.5mm for high-quality steel;

[0090] Outer corner radius: 1.5mm for ordinary steel, 1.0mm for high-quality steel.

[0091] S2 and S3, mixed processing of rolls and dynamic adjustment of grooves

[0092] The Φ28mm high-quality steel and ordinary steel pass profiles are machined into different grooves on the same roll. According to Table 2, the maximum number of grooves is 12. For example, the planned output of ordinary steel accounts for 50% and the high-quality steel accounts for 50%. Then, the number of grooves for ordinary steel is 6 and the number of grooves for high-quality steel is 6.

[0093] S4. Parameter Optimization and Adjustment

[0094] In the initial parameters, the expansion radius of ordinary steel is 21.27 mm, the expansion radius of high-quality steel is 26 mm, the measured ellipticity of ordinary steel is 0.40 mm, and the measured ellipticity of high-quality steel is 0.28 mm.

[0095] Adjust the parameters:

[0096] For ordinary steel, the expansion radius is 20mm, and the correction range is -1.27mm, ≤5% of the original value;

[0097] The expansion radius of the high-quality steel is 25mm, and the correction range is -1.0mm, ≤5% of the original value;

[0098] Roll gap adjustment: The roll gap for both ordinary steel and high-quality steel is 3.5mm;

[0099] External fillet optimization: The external fillet radius of high-quality steel is reduced to 0.8mm, while that of ordinary steel remains at 1.5mm. The optimization results in a reduction of the ellipticity of the high-quality steel to 0.25mm, achieving dimensional accuracy meeting national standard group II. The optimized Φ28mm parameters are archived as "High-quality round 28" and "Ordinary round 28" respectively.

[0100] Table 1 Optimized hole profile parameters

[0101]

[0102] Table 2 Maximum Number of Roll Grooves

[0103]

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for designing pass profiles in the production of bar stock using a mixture of high-quality steel and ordinary steel, characterized in that, Includes the following steps: S1. For round steel bars with diameters from Φ20mm to Φ45mm, design finished die patterns for high-quality steel and ordinary steel respectively, wherein: The base circle radius of the finished die for high-quality steel is designed based on the upper limit of the positive tolerance of the national standard, while the base circle radius of the finished die for ordinary steel is designed based on the lower limit of the negative tolerance of the national standard. The difference in base circle radius between high-quality steel and ordinary steel is 0.15mm~0.25mm; S2. The finished steel roll pass and the finished steel roll pass are machined into different grooves of the same roll, and the maximum number of grooves of the roll is dynamically adjusted according to the specifications. S3. Based on the total output of a single batch and the steel throughput per slot, allocate the number of rolling slots according to the ratio of high-quality steel to ordinary steel output, wherein: For Φ20mm~Φ28mm specifications, the maximum number of slots is 12~15; For specifications of Φ30mm~Φ45mm, the maximum number of slots is 8~12; S4. Based on the measured ellipticity and dimensional parameters of the finished product during the rolling process, the expansion radius, roll gap, and outer corner radius of the high-quality steel roll and the ordinary steel roll are optimized and iterated until the ellipticity of the high-quality steel is ≤0.3mm and the dimensional accuracy reaches or exceeds the national standard group II.

2. The method for designing the pass profile for the mixed production of high-quality steel and ordinary steel bars according to claim 1, characterized in that, In step S1, the expansion radius of the finished die of the high-quality steel is set to 20mm~28mm, and the expansion radius of the finished die of the ordinary steel is set to 23mm~31mm. The expansion angle of the high-quality steel and the ordinary steel is set to 30° or 35° according to the specifications, and the difference between the expansion angle of the high-quality steel and the ordinary steel under the same specifications does not exceed 5°.

3. The method for designing the pass profile in the mixed production of high-quality steel and ordinary steel bars according to claim 1, characterized in that, The dynamic adjustment rule for the number of grooved rolls is as follows: For every 5mm increase in size, the maximum number of grooves decreases by 1 to 2. Specifically, Φ20mm corresponds to 15 grooves, and Φ45mm corresponds to 8 grooves. Furthermore, the number of grooves decreases in a stepwise manner as the size increases.

4. The method for designing the pass profile in the mixed production of high-quality steel and ordinary steel bars according to claim 1, characterized in that, The rule for configuring the number of rolling grooves in step S3 is as follows: Let the total number of holes and slots be N. 总 The planned output of ordinary steel accounts for P%, and the planned output of high-quality steel accounts for Y%, satisfying the condition that P% + Y% = 100%; The number of holes and slots in ordinary steel is determined by N. 总 The result of ×P% is rounded to the nearest integer. Number of holes and slots in high-quality steel = N 总 - Number of holes and slots in ordinary steel.

5. The method for designing the pass profile for the mixed production of high-quality steel and ordinary steel bars according to claim 1, characterized in that, The rolling mill in step S2 is processed in stages. The initial roll profile parameters are set based on theoretical calculations. The expansion radius is corrected and the outer corner radius is optimized based on the actual rolling size data. The correction range does not exceed 5% of the original parameter value.

6. The method for designing the pass profile in the mixed production of high-quality steel and ordinary steel bars according to claim 1, characterized in that, The method covers round steel specifications ranging from Φ20mm to Φ45mm, and the die parameters for high-quality steel and ordinary steel are stored and retrieved separately through independent process procedures.

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