Edge cutting method for high-grade non-oriented silicon steel hot-rolled strip steel

Abstract

The invention relates to an edge cutting method for high-grade non-oriented silicon steel hot-rolled strip steel. The edge cutting method comprises the steps that a steel coil raw material is obtained; and the steel coil raw material is sequentially subjected to slow cooling, uncoiling, head and tail cutting, disc edge cutting, edge crushing and coiling, and the finished hot rolled steel coil is obtained. In order to solve the edge quality problem easily occurring in the edge cutting process of the non-oriented silicon steel with high silicon content, high nickel content, thin and wide specification, wide width and high grade, the method determines full-process control points with logistics turnover, on-machine temperature, edge cutting temperature, process temperature drop and disc shear blade clearance as the core. According to the invention, through the precise control of the narrow window in the whole process from hot rolling off-line to material dump, a good temperature guarantee is provided for the trimming process, smooth and stable trimming is finally realized, the trimming yield and the product quality are effectively improved, and the strict requirement of a user on the edge quality of a trimming raw material is met.

Description

Technical Field

[0001] This application relates to the field of strip steel processing technology, and in particular to a method for trimming high-grade non-oriented silicon steel hot-rolled strip. Background Technology

[0002] With the rapid development of strategic emerging industries such as new energy vehicles and drones, the evolution of drive motors for these industries towards higher power density, longer range, and higher speed is accelerating. This places extremely stringent performance requirements on high-grade non-oriented silicon steel, a core soft magnetic material. Specifically, high-grade non-oriented silicon steel must possess extremely low iron loss, high magnetic induction, and excellent mechanical strength.

[0003] To meet these requirements, the design of new-generation high-grade non-oriented silicon steel typically employs methods that significantly increase silicon content and add more alloying elements. However, this approach also presents significant process challenges: the steel's brittleness increases markedly, making it highly susceptible to defects such as breakage, coiling failures, and edge cracking during the hot-rolled raw material trimming process at low temperatures. This has resulted in a yield rate of only about 30% in the trimming process, causing not only substantial cost losses but also becoming a bottleneck restricting the final realization of high-grade non-oriented silicon steel products for new energy vehicles and drones, severely hindering the development and market promotion of these products. Summary of the Invention

[0004] This application provides a method for trimming the edges of high-grade non-oriented silicon steel hot-rolled strip to solve the following technical problem: how to improve the yield of high-grade non-oriented silicon steel hot-rolled strip. This application provides a method for trimming the edge of high-grade non-oriented silicon steel hot-rolled strip, including: Obtain steel coil raw material; The steel coil raw material is subjected to slow cooling, uncoiling, head and tail trimming, disc edge trimming, edge crushing, and coiling in sequence to obtain the finished hot-rolled steel coil.

[0005] Optionally, after the slow cooling, the temperature of the steel coil raw material is 100℃~170℃.

[0006] Optionally, the unwinding tension is 20KN~50KN.

[0007] Optionally, in the head and tail cutting, the length of the cut strip tail is ≥10m.

[0008] Optionally, the running speed of the strip steel cut by the disc is ≤100m / min.

[0009] Optionally, when the ambient temperature of the disc cutting edge is ≤10℃, the strip steel in operation is actively insulated, and the active insulation is achieved by at least one of an insulation curtain and a hot air blower.

[0010] Optionally, the strip temperature of the disc cut edge is ≥60℃.

[0011] Optionally, the side clearance S1 of the disc cutting edge satisfies: S1=D×k1+△; where D is the strip thickness in mm; k1 is the proportional coefficient, k1: 7.5%~10%; and △ is the fine adjustment amount.

[0012] Optionally, the gap S2 of the broken edge satisfies: S2=D×k2; where D is the strip thickness in mm; k2 is a proportionality coefficient, k2: 7.5%~15%.

[0013] Optionally, the winding tension is 20KN~60KN.

[0014] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides a method for trimming the edges of high-grade non-oriented silicon steel hot-rolled strip. Through systematic control, temperature management is the core breakthrough point. The temperature after slow cooling is precisely controlled within a low, ideal window, ensuring that the strip temperature during disc trimming is not lower than 60°C. This control strategy aims to keep the material within an optimal range for brittle-plastic transformation, thus balancing the plastic deformation capacity required for trimming with the suppression of brittleness. Based on this, key process parameters are further precisely matched, particularly optimizing the shear blade gap of the disc trimming to achieve a scientific ratio between the shear blade gap and the strip thickness. This ensures that the shearing force can cleanly and decisively cut the material, rather than tearing or squeezing due to parameter mismatch, thereby mechanistically avoiding damage to vulnerable edges. Simultaneously, by setting sufficient head and tail lengths, adequate stability is provided for the threading process, ensuring that the strip can smoothly establish uniform tension and effectively preventing the risk of fracture induced by sudden tension changes in brittle materials.

[0015] In summary, this solution does not involve adjusting a single parameter in isolation, but rather achieves a complete solution through the synergistic effect of temperature control, process parameter optimization, and process stability assurance. This method systematically improves the mechanical behavior of hot-rolled high-brittle non-oriented silicon steel strip during the edge-cutting process, ultimately achieving a significant increase in yield and successfully solving a key bottleneck restricting mass production. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating a method for trimming high-grade non-oriented silicon steel hot-rolled strip, provided as an embodiment of this application; Figure 2 A photograph of the improved high-grade non-oriented silicon steel hot-rolled strip before coiling breakage and edge crack defects provided in the embodiments of this application; Figure 3 The image shows a finished steel coil with good edge quality of the improved high-grade non-oriented silicon steel hot-rolled strip provided in the embodiments of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] The range descriptions used herein, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within that range. For example, the range descriptions of "1 to 6" or "1~6" cover all sub-ranges between 1 and 6 (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6). Unless otherwise specified, the terms "including" and "contains" used herein mean "including but not limited to"; relational terms such as "first" and "second" are used only to distinguish different entities or operations and do not imply an actual order or relationship. "And / or" indicates that multiple situations can exist individually or simultaneously. Expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. The proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as the correspondence between the first and second terms of a proportional formula, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained through commercial purchase or prepared using existing methods.

[0021] Figure 1 This is a flowchart illustrating a method for trimming high-grade non-oriented silicon steel hot-rolled strip, as provided in an embodiment of this application.

[0022] Please see Figure 1This application provides a method for trimming the edge of high-grade non-oriented silicon steel hot-rolled strip, including: S1. Obtain steel coil raw material; S2. The steel coil raw material is subjected to slow cooling, uncoiling, head and tail trimming, disc edge trimming, edge crushing and coiling in sequence to obtain the finished hot-rolled steel coil.

[0023] In the above technical solution, precise temperature control and morphology processing of the steel coils ensure the smooth progress of the edge trimming process and the edge quality of the final product. The edge trimming process begins when the steel coil raw material is unloaded from the production line. Initial temperature measurement is performed on the unloaded tray, and the coil is then subjected to slow cooling in an insulation pit. The purpose is to ensure that the internal temperature of the steel coil drops evenly, avoiding stress concentration or uneven mechanical properties caused by excessively rapid cooling. Subsequently, dynamic temperature monitoring is used to ensure that the steel coil is within a suitable temperature range when it enters subsequent processing. Excessive temperature can easily lead to edge tearing, while excessively low temperature increases the risk of brittle fracture. After the steel coil is delivered to the raw material preparation station, it is sequentially uncoiled by an uncoiler, then straightened by a straightener to eliminate strip shape defects and restore the straightness of the strip. Subsequently, the head cutter removes the irregular part of the head, providing a neat end face for subsequent finishing processing. The alignment roller adjusts the running trajectory of the strip to ensure that it travels stably along the center line of the unit and avoids deviation. Finally, the strip steel enters the core disc for precise edge trimming, and the waste edges are simultaneously crushed. The strip is then re-coiled by the coiler into a finished hot-rolled steel coil with acceptable edge quality. The entire process, through the synergistic effect of temperature control and morphology processing, provides stable and high-quality edge trimming conditions for high-grade silicon steel.

[0024] In some embodiments, the temperature of the steel coil raw material after the slow cooling is 100°C to 170°C.

[0025] After slow cooling, the temperature of the steel coil raw material is between 100℃ and 170℃, placing the coil in a plastic state conducive to edge cutting and preventing it from sticking to the cutter due to excessively high temperatures or cracking due to excessively low temperatures. To reduce temperature loss during the material's transit, the production line maintains a two-coil turnover (one coil at the preparation station and one coil at the uncoiler), ensuring that the temperature before uncoiling is not lower than 100℃, with temperature measurement taken at the end of the coil. For example, the temperature of the steel coil raw material can be 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, etc.

[0026] In some embodiments, the unwinding tension is 20KN~50KN.

[0027] The uncoiling tension is between 20KN and 50KN to ensure the strip steel unfolds smoothly from the drum, avoiding strip deviation, waviness, or loosening due to insufficient tension, while also preventing excessive plastic stretching or potential breakage of the strip steel, which has poor toughness at low temperatures, before straightening and trimming due to excessive tension. For example, the uncoiling tension can be 20KN, 25KN, 30KN, 35KN, 40KN, 45KN, or 50KN.

[0028] In some embodiments, the length of the strip tail removed during the head and tail cutting is ≥10m.

[0029] In the process of cutting off the head and tail of the strip, the length of the strip tail removed is ≥10m. The purpose is to ensure the stability and reliability of the strip threading process and to prevent strip breakage. For example, the length of the strip tail removed ≥10m can be 10m, 11m, 12m, 13m, 14m, 15m, etc.

[0030] In some embodiments, the running speed of the strip at the disc cutting edge is ≤100m / min.

[0031] The strip running speed of the disc shearing process is ≤100m / min. The purpose is to precisely control the dynamic mechanical behavior of the shearing process to achieve a high-quality strip shearing effect and ensure process stability. For example, the strip running speed of the disc shearing process can be 80m / min, 85m / min, 90m / min, 95m / min, 100m / min, etc.

[0032] In some embodiments, when the ambient temperature of the disc cutting edge is ≤10°C, the strip steel in operation is actively insulated, and the active insulation is achieved by at least one of an insulation curtain and a hot air blower.

[0033] When the ambient temperature of the disc cutting edge is ≤10℃, the strip steel is actively insulated by the heat insulation curtain or hot air blower. The purpose is to compensate for the heat loss of the strip steel during the conveying process and ensure that the temperature of the strip steel when entering the disc cutting edge is always not lower than the process requirement of 60℃, thereby maintaining the plasticity of the strip steel and preventing the deterioration of the cutting edge quality due to low temperature brittleness.

[0034] In some embodiments, the strip temperature of the disc cut edge is ≥60°C.

[0035] The strip temperature during disc trimming is ≥60℃. This temperature maintains the strip's necessary plasticity during shearing, preventing embrittlement due to excessively low temperatures. This avoids defects such as edge cracks, microscopic notches, or breakage during trimming, and is a crucial temperature guarantee for ensuring the final trimmed section quality and geometric accuracy. For example, the strip temperature during disc trimming can be 60℃, 62℃, 64℃, 66℃, 68℃, 70℃, etc.

[0036] In some embodiments, the side clearance S1 of the disc tangent satisfies: S1=D×k1+△; where D is the strip thickness in mm; k1 is a proportionality coefficient, k1: 7.5%~10%; and △ is the fine adjustment amount.

[0037] The side clearance S1 of the disc shearing edge satisfies: S1 = D × k1 + Δ. Its function is to achieve an optimal match between the shearing force and the strip characteristics, thereby obtaining a clean cut edge and maximizing tool life. The basic clearance (D × k1, where k1: 7.5%~10%) ensures that the shearing blade can cleanly cut the strip rather than tear it, which is crucial for the brittle nature of the strip. The fine-tuning amount Δ (-0.07mm~0.07mm) provides compensation for minor fluctuations in strip thickness, material inhomogeneity, or shearing blade wear, ensuring the stability and adaptability of the process across different production batches. For example, the proportional coefficient k1 can be 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, etc.

[0038] In some embodiments, the gap S2 of the broken edge satisfies: S2=D×k2; where D is the strip thickness in mm; and k2 is a proportionality coefficient, k2: 7.5%~15%.

[0039] The gap S2 of the scrap edge satisfies: S2 = D × k2 (where k2: 7.5%~15%). Its function is to ensure that the scrap edge cut by the disc shear is cleanly and efficiently broken, while avoiding damage to the main strip or accelerated tool wear. For example, the proportionality coefficient k2 can be 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc.

[0040] In some embodiments, the winding tension is 20 kN to 60 kN.

[0041] The winding tension is between 20KN and 60KN to ensure that the strip steel after edge trimming can be tightly and neatly wound into shape, while preventing damage to the edge quality or shape of the strip steel due to improper tension. For example, the winding tension can be 20KN, 30KN, 40KN, 50KN, 60KN, etc.

[0042] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards / industry standards / the disclosure herein; if there are no corresponding national standards / industry standards / the disclosure herein, they are performed according to generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer.

[0043] Example 1 Obtain steel coil raw material; The steel coil raw material is slowly cooled to a temperature of 100℃. The coil is then uncoiled at a tension of 20KN. The uncoiled strip is then trimmed at both ends, with a tail length of ≥10m defined as 10m. Next, the strip is subjected to disc trimming at a speed of 80m / min, a temperature of 90℃, and a side clearance of 0.15mm. The strip is then edge-trimmed with a gap of 0.20mm. Finally, the strip is coiled at a tension of 30KN to obtain the finished hot-rolled steel coil.

[0044] In this process, to ensure consistently stable cutting quality, the disc cutting edge follows the principle of quality first, implementing a system of replacing the edge every 5 rolls or immediately replacing it when defects such as chipped blades occur; broken edges are replaced immediately when three consecutive cuts fail to cut through the edge during production.

[0045] Example 2 Obtain steel coil raw material; The steel coil raw material is slowly cooled to a temperature of 110°C. The coil is then uncoiled at a tension of 30 kN. The uncoiled strip is then trimmed at both ends, with the tail section being ≥10 m long (or 11 m). Next, the strip is subjected to disc trimming at a speed of 88 m / min, a temperature of 92°C, and a side clearance of 0.16 mm. The strip is then edge-trimmed with a gap of 0.22 mm. Finally, the strip is coiled at a tension of 35 kN to obtain the finished hot-rolled steel coil.

[0046] In this process, to ensure consistently stable cutting quality, the disc cutting edge follows the principle of quality first, implementing a system of replacing the edge every 5 rolls or immediately replacing it when defects such as chipped blades occur; broken edges are replaced immediately when three consecutive cuts fail to cut through the edge during production.

[0047] Example 3 Obtain steel coil raw material; The steel coil raw material is slowly cooled to a temperature of 130°C. The coil is then uncoiled at a tension of 40 kN. The uncoiled strip is then trimmed at both ends, with the tail section being 12 m if the length is ≥10 m. Next, the strip is subjected to disc trimming at a speed of 91 m / min, a temperature of 96°C, and a side clearance of 0.18 mm. The strip is then edge-trimmed with a gap of 0.24 mm. Finally, the strip is coiled at a tension of 40 kN to obtain the finished hot-rolled steel coil.

[0048] In this process, to ensure consistently stable cutting quality, the disc cutting edge follows the principle of quality first, implementing a system of replacing the edge every 5 rolls or immediately replacing it when defects such as chipped blades occur; broken edges are replaced immediately when three consecutive cuts fail to cut through the edge during production.

[0049] Example 4 Obtain steel coil raw material; The steel coil raw material is slowly cooled to a temperature of 150°C. The coil is then uncoiled at a tension of 45 kN. The uncoiled strip is then trimmed at both ends, with the tail section being ≥10 m long (13 m). Next, the strip is subjected to disc trimming at a speed of 95 m / min, a temperature of 120°C, and a side clearance of 0.19 mm. The strip is then edge-trimmed with a gap of 0.25 mm. Finally, the strip is coiled at a tension of 50 kN to obtain the finished hot-rolled steel coil.

[0050] In this process, to ensure consistently stable cutting quality, the disc cutting edge follows the principle of quality first, implementing a system of replacing the edge every 5 rolls or immediately replacing it when defects such as chipped blades occur; broken edges are replaced immediately when three consecutive cuts fail to cut through the edge during production.

[0051] Example 5 Obtain steel coil raw material; The steel coil raw material is slowly cooled to a temperature of 170°C. The coil is then uncoiled at a tension of 50 kN. The uncoiled strip is then trimmed at both ends, with a tail length of ≥10 m being 14 m. Next, the strip is subjected to disc trimming at a speed of 100 m / min, a temperature of 130°C, and a side clearance of 0.20 mm. The strip is then edge-trimmed with a gap of 0.26 mm. Finally, the strip is coiled at a tension of 60 kN to obtain the finished hot-rolled steel coil.

[0052] In this process, to ensure consistently stable cutting quality, the disc cutting edge follows the principle of quality first, implementing a system of replacing the edge every 5 rolls or immediately replacing it when defects such as chipped blades occur; broken edges are replaced immediately when three consecutive cuts fail to cut through the edge during production.

[0053] Comparative Example 1 Obtain steel coil raw material; The steel coil raw material is slowly cooled to a temperature of 71°C. The coil is then uncoiled at a tension of 10 kN. The uncoiled strip is then trimmed at both ends, with a tail length of ≥10 m being 350 m. Next, the strip is subjected to disc trimming at a speed of 120 m / min, a temperature of 60°C, and a side clearance of 0.25 mm. The strip is then edge-trimmed with a gap of 0.40 mm. Finally, the strip is coiled at a tension of 10 kN to obtain the finished hot-rolled steel coil.

[0054] In this process, to ensure consistently stable cutting quality, the disc cutting edge follows the principle of quality first, implementing a system of replacing the edge every 5 rolls or immediately replacing it when defects such as chipped blades occur; broken edges are replaced immediately when three consecutive cuts fail to cut through the edge during production. Comparative Example 2 Obtain steel coil raw material; The steel coil raw material is slowly cooled to a temperature of 80°C. The coil is then uncoiled at a tension of 66 kN. The uncoiled strip is then trimmed at both ends, with a tail length of ≥10 m (or 500 m). Next, the strip is subjected to disc trimming at a speed of 130 m / min, a temperature of 75°C, and a side clearance of 0.30 mm. The strip is then edge-trimmed with a gap of 0.45 mm. Finally, the strip is coiled at a tension of 80 kN to obtain the finished hot-rolled steel coil.

[0055] In this process, to ensure consistently stable cutting quality, the disc cutting edge follows the principle of quality first, implementing a system of replacing the edge every 5 rolls or immediately replacing it when defects such as chipped blades occur; broken edges are replaced immediately when three consecutive cuts fail to cut through the edge during production.

[0056] Effect data: The effect data of Examples 1 to 5 and Comparative Examples 1 to 2 are shown in Table 1.

[0057] Experimental methods for obtaining effect data: 1. Calculation of yield rate: Yield rate = Weight of finished rolls / Weight of raw material rolls fed into the production line.

[0058] Table 1

[0059] The above effect data table provides a clear comparison of the differences between various embodiments and comparative examples. The following conclusions can be drawn: As can be seen from Examples 1-5 and Comparative Examples 1-2, Examples 1-5, within the optimized process parameter range and combined with a strict shear blade replacement system, achieved an ultra-high and stable yield (≥96%) of high-grade non-oriented silicon steel edge cutting, which is significantly better than Comparative Examples 1-2. However, Comparative Examples 1-2, due to the serious deviation of key parameters from the reasonable range, resulted in frequent edge cracking, breakage, and strip breakage during the edge cutting process, causing a sharp increase in cutting losses and a precipitous drop in yield. This confirms the effectiveness and necessity of the method in the embodiments of this application for solving edge cutting defects of high-grade silicon steel.

[0060] Appendix Figures 2-3 Detailed explanation: Figure 2 The image shows actual photographs of high-grade non-oriented silicon steel hot-rolled strip before the improvement provided in this application, illustrating coil breakage and edge crack defects. According to... Figure 2 It is known that before the improvement, the hot-rolled strip of high-grade non-oriented silicon steel had obvious breakage and edge crack defects during coiling, resulting in low yield and substandard product quality.

[0061] Figure 3 A photograph of the finished steel coil with good edge quality of the improved high-grade non-oriented silicon steel hot-rolled strip provided in this application embodiment. According to... Figure 3 It can be seen that the improved high-grade non-oriented silicon steel hot-rolled strip has a smooth edge texture, free from cracks, breaks, burrs, and other defects, and the edge quality is significantly improved. This shows that the edge trimming process in this application embodiment effectively solves the problems of breakage and edge cracking during coiling before the improvement, achieving a balance between high yield and high quality.

[0062] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed in this application.

Claims

1. A method for trimming the edge of high-grade non-oriented silicon steel hot-rolled strip, characterized in that, The method includes: Obtain steel coil raw material; The steel coil raw material is subjected to slow cooling, uncoiling, head and tail trimming, disc edge trimming, edge crushing, and coiling in sequence to obtain the finished hot-rolled steel coil.

2. The method according to claim 1, characterized in that, After the slow cooling process, the temperature of the steel coil raw material is 100℃~170℃.

3. The method according to claim 1, characterized in that, The unwinding tension is 20KN~50KN.

4. The method according to claim 1, characterized in that, In the head and tail cutting process, the length of the cut strip tail is ≥10m.

5. The method according to claim 1, characterized in that, The running speed of the strip steel cut by the disc is ≤100m / min.

6. The method according to claim 1, characterized in that, When the ambient temperature of the disc cutting edge is ≤10℃, the strip steel in operation is actively insulated. The active insulation is achieved by at least one of the insulation curtain and hot air blower.

7. The method according to claim 1, characterized in that, The temperature of the strip steel cut at the edge of the disc is ≥60℃.

8. The method according to claim 1, characterized in that, The side clearance S1 of the disc cutting edge satisfies: S1=D×k1+△; where D is the strip thickness in mm; k1 is the proportional coefficient, k1: 7.5%~10%; △ is the fine adjustment amount.

9. The method according to claim 1, characterized in that, The gap S2 of the broken edge satisfies: S2=D×k2; where D is the strip thickness in mm; k2 is a proportionality coefficient, k2: 7.5%~15%.

10. The method according to claim 1, characterized in that, The winding tension is 20KN~60KN.

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