Method and system for improving the quality of the surface of a steel coil and reducing the occurrence of strip breaks

Abstract

The application discloses a method and system for improving the quality of a steel coil plate surface and reducing strip breakage, and relates to the technical field of steel cold rolling processing. The method comprises a welding process and a phosphorus breaking and tension leveling process. In the welding process, the strip head and tail of the front and rear steel coils are welded and connected. In the phosphorus breaking and tension leveling process, the welded steel plate is subjected to combined deformation of stretching and bending. The elongation is controlled according to the steel plate grade, and the insertion amount of the phosphorus breaking and tension leveling roller is adjusted according to the steel plate grade and the silicon content, so that the plate shape is improved and the stress is eliminated. The method establishes a collaborative control system of welding parameters and phosphorus breaking and tension leveling parameters, and adopts differentiated setting according to different grades and material characteristics, so that the problem of strip breakage caused by the insufficient weld strength and the upward bending of the strip head and tail of the high yield strength steel plate after straightening is solved.

Description

Technical Field

[0001] This invention relates to the field of cold rolling technology for steel, and in particular to a method and system for improving the surface quality of steel coils and reducing strip breakage. Background Technology

[0002] In cold rolling steel production, continuous production lines require welding connecting consecutive steel coils to achieve uninterrupted processing. The welded steel plates then undergo straightening and tension straightening processes to improve their shape and eliminate internal stress, thereby meeting the quality requirements of subsequent processing and the final product. With the widespread application of high-strength steel plates, ensuring welding quality and plate shape control during continuous production has become a crucial technical challenge.

[0003] Chinese patent CN106694637A discloses an automatic straightening method for high-yield-strength low-alloy steel. This method first determines the yield strength and plate thickness of the 450-600 MPa high-yield-strength low-alloy steel, then inputs these values ​​into a straightening model to obtain the actual straightening force, and finally straightens the high-yield-strength low-alloy steel. This method calculates the straightening force by establishing a straightening model, enabling targeted automatic straightening of high-yield-strength steel plates. However, this method only focuses on the calculation and control of the straightening force during the straightening process, without addressing the impact of welding processes on subsequent processing, nor considering the effect of elongation control on plate shape.

[0004] Chinese patent CN103962419A discloses a method for improving the shape of cross-cut high-strength steel plates. This method controls the final transverse unevenness of the steel plate by adjusting the coarse straightening parameters in stages, and controls the final longitudinal unevenness of the steel plate by adjusting the fine straightening parameters in stages. This method specifically improves the adjustment and control of the roll gap between the coarse and fine straightening machines in the cross-cutting unit, ensuring that the steel plate achieves good straightening results at different stages. However, this method is designed for the cross-cutting process and requires segmented processing of the steel plate, making it unsuitable for the process requirements of continuous production lines.

[0005] In actual continuous production processes, inlet straightening machines often lack clear standard settings for process parameters when processing steel plates with beginnings and ends. This is especially true when producing steel plates with high yield strength, where the straightened beginnings and ends are prone to shape defects, affecting the smooth flow of the steel plates through the production line. Furthermore, the parameter settings for the welding process significantly impact weld quality, which in turn directly affects the continuity of the steel plates in subsequent tension straightening processes. Different grades and material properties of steel plates require different process parameters during processing, and current technology lacks a systematic method for differentiated parameter settings tailored to the specific characteristics of different steel plates.

[0006] Therefore, there is a need for a production method that can comprehensively consider the coordinated control of welding and straightening process parameters and can differentiate the processing according to the steel plate grade and material characteristics, so as to improve the surface quality of steel coils and reduce strip breakage during the production process. Summary of the Invention

[0007] The purpose of this invention is to provide a method and system for improving the surface quality of steel coils and reducing strip breakage, so as to solve the following technical problems existing in the prior art:

[0008] (1) Existing technology only focuses on the calculation and control of straightening force in the straightening process, without considering the impact of welding process on subsequent processing, resulting in insufficient weld strength after welding of high yield strength steel plates, which is prone to breakage when passing through the phosphorus-breaking straightening machine;

[0009] (2) The existing technology does not involve elongation control. The residual stress distribution at the head and tail of the straightened strip is uneven, resulting in an upward tilting phenomenon. When the strip enters the welding machine through the channel, it is easy to collide with the channel gap, requiring the machine to be stopped for manual adjustment, which affects production efficiency.

[0010] (3) Existing technologies lack a systematic method for setting differentiated parameters for steel plates of different grades and material properties. When using uniform process parameters to process steel plates of different strengths, high-strength steel plates are prone to quality problems, and high-silicon content steel plates are prone to breakage due to their high brittleness.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] This invention provides a method for improving the surface quality of steel coils and reducing strip breakage, used in the continuous production and processing of high yield strength steel plates, including a welding process and a phosphorus removal and straightening process performed sequentially;

[0013] The welding process involves welding and fixing the tail of the preceding steel coil to the head of the following steel coil, thereby achieving continuous production of steel coils.

[0014] The phosphorus-breaking and straightening process involves performing a combination of stretching and bending plastic deformation on the welded steel plate. During the process, the elongation rate of the steel plate is controlled according to its grade, and the insertion amount of the phosphorus-breaking and straightening rollers is adjusted according to the grade and silicon content of the steel plate.

[0015] Preferably, in the welding process, the welding speed is controlled at 3.0-6.0 m / min and the welding power is controlled at 3.5-5.5 KW.

[0016] Preferably, after the welding process is completed, a quality verification experiment is performed on the weld; the quality verification experiment includes a cupping test and a bending test, and only the cupping test is performed on high-grade steel plates.

[0017] Preferably, when producing high-grade steel plates, if the difference in rolling force between the front and rear steel coils exceeds a preset threshold, medium-grade steel coils are used as transition material for welding connection.

[0018] Preferably, in the phosphorus breaking and straightening process, corresponding elongation modes are matched for steel coils of different grades (low, medium, and high), and the elongation control range of the steel plate is 0.5%-2.3%.

[0019] Preferably, in the phosphorus-breaking and straightening process, the higher the silicon content of the steel plate, the smaller the gradient of the insertion amount of the phosphorus-breaking and straightening roller, so as to avoid brittle fracture of the high-silicon steel plate.

[0020] Preferably, after the welding process is completed and the steel plate is released into subsequent processes, the anti-wrinkle roller is not in use.

[0021] Preferably, before the welding process, a pre-treatment process for straightening the head and tail of the steel coil is set to straighten the steel plate of a preset length at the head and tail. The straightening parameters are set according to the steel plate grade to eliminate the upturning defects at the head and tail.

[0022] Preferably, in the phosphorus breaking and straightening process, based on the weld quality verification results of the welding process, the elongation of the steel plate and the insertion amount of the phosphorus breaking and straightening roller are finely adjusted in conjunction to ensure that the weld does not break when passing through the phosphorus breaking and straightening process.

[0023] This invention also provides a system for improving the surface quality of steel coils and reducing strip breakage, used in the continuous production and processing of high yield strength steel plates, including a welding execution module, a phosphorus removal and tension straightening execution module, and a process control module:

[0024] The welding execution module is used to complete the welding and fixing of the tail of the preceding steel coil and the head of the subsequent steel coil, so as to realize the process connection of continuous steel coil production.

[0025] The phosphorus-breaking and straightening execution module is used to apply a combination of tensile and bending plastic deformation to the welded steel plate to complete the phosphorus-breaking and plate straightening process of the steel plate.

[0026] The process control module is communicatively connected to the welding execution module and the phosphorus removal and straightening execution module. The process control module has a built-in grade-elongation matching database and a grade-silicon content-straightening roll insertion amount matching database. The process control module is configured to: when the phosphorus removal and straightening execution module is operating, retrieve the grade information of the steel plate to be processed, match and output the corresponding elongation control parameters to the phosphorus removal and straightening execution module, and simultaneously retrieve the grade and silicon content information of the steel plate to be processed, match and output the corresponding straightening roll insertion amount control parameters to the phosphorus removal and straightening execution module.

[0027] As can be seen from the above technical solutions, this invention application has the following beneficial effects:

[0028] This invention addresses industry pain points in the continuous cold rolling production of high-yield-strength electrical steel, including strip tip and tail warping, insufficient weld strength, brittle strip breakage in high-silicon steel, and poor strip surface quality. Through comprehensive process optimization—including strip tip and tail straightening pretreatment, refined parameter matching in welding procedures, closed-loop verification of weld quality, and differentiated control of phosphorus removal and straightening processes—a complete process system is established, precisely matched according to steel grade, silicon content, normalization state, and thickness. This invention significantly reduces the frequency of strip breakage and unplanned equipment downtime, reduces manual intervention costs, significantly improves strip surface quality and product qualification rate, while reducing roll replacement and maintenance costs. It effectively enhances the operational stability, production efficiency, and product consistency of continuous high-strength electrical steel production, demonstrating excellent field application value and economic benefits. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Referring to the drawings will make the features and advantages of the present invention clearer. The drawings are illustrative and should not be construed as limiting the present invention in any way. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0030] Figure 1 This is a flowchart of a method for improving the surface quality of steel coils and reducing strip breakage provided by the present invention;

[0031] Figure 2 This is a block diagram of a system for improving the surface quality of steel coils and reducing strip breakage, provided by the present invention. Detailed Implementation

[0032] 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, not all embodiments. 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.

[0033] This invention discloses a method and system for improving the surface quality of steel coils and reducing strip breakage. It is applied to the entire process of cold rolling continuous production of high yield strength steel plates. By coordinating and optimizing the parameters of the entire process, including strip straightening pretreatment, welding, weld quality control, and phosphorus removal and straightening, as well as differentiated process control for steel plates of different grades and silicon contents, it solves the technical problems of strip curling at the head and tail, poor weld fit, false welds, insufficient weld strength, strip breakage during phosphorus removal and straightening, and poor plate surface quality in existing continuous production of high yield strength steel plates. It achieves a dual improvement in production efficiency and product qualification rate, while reducing the cost of roll replacement and maintenance, equipment downtime, and labor costs.

[0034] The method for improving the surface quality of steel coils and reducing strip breakage as described in this invention, such as... Figure 1 As shown, the process includes a pre-treatment step of straightening with both ends, a welding step, a weld quality verification step, and a phosphorus removal and straightening step, which are performed sequentially. The specific implementation methods for each step are as follows:

[0035] In step S1, a pre-treatment process for straightening the head and tail of the steel coil is performed. This process is a pre-treatment step before welding. Before the steel coil enters the welding process, the steel plate of a preset length (60 meters) at the head and tail of the steel coil is straightened by an inlet straightening machine. In this embodiment, the preset length is 60 meters. Addressing the problem in the prior art where there are no clear process parameters for straightening this section of the steel plate, and the tendency for the head and tail of the straightened steel plate to exhibit obvious upward curling (tightening) when producing high yield strength steel plates (such as SG50W470), this process sets the insertion depth and straightening parameters of the straightening machine according to the grade of the steel plate to be processed. Through repeated on-site adjustments and optimization of the straightening machine's insertion gap, the upward curling defect at the head and tail of the steel coil is eliminated.

[0036] This straightening pretreatment process prevents the straightened strip head from colliding with the gaps in the welding machine channel during its entry, ensuring normal passage without requiring manual intervention. Simultaneously, it improves the welding fit between the strip head and tail during subsequent welding, eliminating incomplete welds and enhancing the cleaning effect on the strip surface. This reduces the risk of strip breakage and improves surface quality from the production front end.

[0037] The high yield strength steel plate targeted by this invention is a low alloy high strength steel plate or non-oriented electrical steel plate with a yield strength ≥ 450 MPa. Typical grades include, but are not limited to, SG50W470, SG50W600, SG50W310, SG35W440, etc.

[0038] In step S2, a welding process is performed: After completing the pre-treatment of straightening the strip head and tail, this welding process is executed to weld and fix the tail of the preceding steel coil to the head of the subsequent steel coil using a welding machine, thus achieving process connection in continuous steel coil production. In this process, the welding speed is controlled between 3.0-6.0 m / min, and the welding power is controlled between 3.5-5.5 KW. Precise control of these parameters ensures the quality and strength of the weld formation, avoids the problem of easy weld breakage after welding, and lays the foundation for the stable operation of subsequent processes.

[0039] For steel plates of different grades and thicknesses to be processed, this invention further matches refined welding process parameters, and clarifies the matching rules for core parameters such as welding wire selection, wire feed speed, butt gap (GAP), and heat input, so as to ensure the weld penetration, bonding strength, and forming quality of steel plates of different materials. The specific welding process parameter matching is shown in Table 1 below:

[0040] Table 1 Welding process parameters for different grades of steel plates

[0041] In actual production, the welding parameter combination corresponding to the table above can be selected according to the steel plate grade, thickness and on-site production conditions. When the steel plate thickness deviation exceeds ±0.2mm, the parameters can be adaptively fine-tuned within the laser power range of 3.5-5.5KW and the welding speed range of 3.0-6.0m / min to ensure weld penetration and bonding strength.

[0042] In a preferred embodiment of this process, when the difference in rolling force between the high-grade steel plate and the preceding and following steel coils exceeds a preset threshold, a medium-grade steel coil is used as a transition material for welding. This medium-grade steel coil includes, but is not limited to, W440 grade steel coil. By using this transition material, the stress concentration problem in the weld caused by the excessive difference in rolling force before and after welding the high-grade steel coil is alleviated, further reducing the risk of weld fracture.

[0043] After welding, the anti-wrinkle roller is not used during the process of releasing the steel plate into the subsequent process. This is to avoid additional disturbance to the weld and plate shape caused by the use of the anti-wrinkle roller, to ensure the smooth passage of the steel plate, and to reduce the risk of cracking of the weld due to external force.

[0044] In step S3, a weld quality verification process is performed: After the welding process is completed and before the phosphorus removal and straightening process, this weld quality verification process is carried out to conduct quality verification experiments on the weld to ensure that the welding quality meets the processing requirements of subsequent processes. The quality verification experiments include cupping tests and bending tests; for high-grade steel plates, due to their easy bending properties, only cupping tests are needed to complete the weld quality verification, avoiding irreversible damage to the welds of high-grade steel plates caused by bending tests, while also improving testing efficiency.

[0045] Only steel plates whose weld quality has been verified can be released to proceed to the subsequent phosphorus removal and straightening process; if the verification fails, the welding operation must be repeated to prevent unqualified welds from entering the subsequent process and causing strip breakage accidents.

[0046] In step S4, the phosphorus removal and straightening process is performed: For steel plates whose weld quality has been verified as qualified, this phosphorus removal and straightening process is performed. The steel plate is subjected to plastic deformation treatment by a combination of stretching and bending through the phosphorus removal and straightening machine. The plastic deformation improves the shape of the strip steel plate, eliminates the internal stress of the steel plate, and completes the phosphorus removal treatment of the surface iron oxide scale. At the same time, it ensures that the weld does not break after being extended through the phosphorus removal and straightening machine.

[0047] This invention targets four major categories of steel plates: low-grade, medium-grade, high-grade, and ultra-thin strip. Based on grade characteristics, normalization state, and silicon content, it establishes differentiated phosphorus-removing tension straightening process parameters for the entire series, and clarifies the matching rules for elongation, tension straightening roll insertion amount, and tension straightening machine operation mode, as shown in Table 2 below:

[0048] Table 2 Matching Table of Phosphorus Removal and Tension Straightening Process Parameters for Different Types of Steel Plates

[0049] In the table above, the three sets of values ​​for the insertion amount of the straightening roller correspond to the insertion amount of the bending roller, the insertion amount of the bending roller, and the insertion amount of the straightening roller of the phosphorus-breaking straightening machine, respectively. For high-grade steel plates, the higher the silicon content, the lower limit value of the insertion amount of the straightening roller should be taken to avoid the breakage of high-silicon brittle steel plates. For ultra-thin strip steel plates, the elongation rate should be matched according to the lower limit value of the strip thickness. The thinner the thickness, the closer the elongation rate is to the lower limit value of 0.5%.

[0050] The core control logic for this process is as follows:

[0051] Elongation control: The elongation of the steel plate is controlled according to its grade. Corresponding elongation modes are developed and matched for low, medium, and high-grade steel coils, with an overall elongation control range of 0.5%-2.3%. By setting differentiated elongation modes, the material characteristics of different steel grades are adapted to achieve plate shape improvement and phosphorus removal effects, while avoiding problems such as excessive elongation leading to steel plate or weld fracture, and insufficient elongation resulting in poor plate shape improvement.

[0052] Phosphorus-reducing straightening roller insertion control: The insertion amount of the phosphorus-reducing straightening roller is adjusted according to the steel plate grade and silicon content. Through repeated on-site adjustments and optimization of the insertion gap, the accuracy of the reduction control and the straightening effect are improved. Specifically, the higher the silicon content of the steel plate, the smaller the adjustment gradient of the phosphorus-reducing straightening roller insertion amount. For high-silicon content steel plates with greater brittleness, a small gradient adjustment of the insertion amount avoids sudden changes in reduction that could cause brittle fracture of the steel plate, fundamentally reducing the risk of strip breakage.

[0053] In the preferred embodiment of this process, based on the verification results of the aforementioned weld quality verification process, the elongation of the steel plate and the insertion amount of the phosphorus-breaking straightening roller are finely adjusted in conjunction. When the weld cupping test result is at the lower limit of the qualified range, the elongation of the steel plate is slightly reduced and the insertion amount of the phosphorus-breaking straightening roller is reduced accordingly, so as to further ensure the structural stability of the weld when passing through the phosphorus-breaking straightening process and prevent the occurrence of strip breakage.

[0054] Example 1:

[0055] This embodiment focuses on the continuous cold rolling production of non-oriented electrical steel sheets of grade SG50W470, employing the present invention as follows: Figure 1 The processing method shown is as follows, and the specific implementation steps are as follows:

[0056] S1. Straightening pretreatment of the strip head and tail: The steel plate with a length of 60 meters of strip head and tail of the steel coil of this grade is straightened and pretreated by the inlet straightening machine. The insertion amount and straightening parameters of the straightening machine are matched and set according to the yield strength characteristics of the SG50W470 grade to eliminate the upturning defects of the strip head and tail, ensure the straightness of the strip head and tail, and improve the subsequent welding fit.

[0057] S2. Welding Process: The tail and head of the preceding and following SG50W470 steel coils are welded together. The steel plate thickness is 2.7mm. MG-50T welding wire with a diameter of 0.9mm is used, matching the welding parameters corresponding to 50WH470 in Table 1. The laser power is controlled at 4.0KW, the welding speed at 4.7m / min, the wire feed speed at 2.2m / min, the GAP setting at 0mm, and the linear energy control at 511J / cm. During the steel plate release process after welding, the anti-wrinkle roller is not used. In this embodiment, the preceding and following steel coils are of the same grade, and the difference in rolling force does not exceed the preset threshold, so no transition material is required.

[0058] S3. Weld quality verification: After welding is completed, cupping and bending tests are performed on the welds of the SG50W470 steel plate. If the test results are qualified, the welds are released to proceed to the next process.

[0059] S4. Phosphorus Removal and Straightening Process: For SG50W470 grade steel plates, match the corresponding grade process parameters in Table 2:

[0060] When the steel plate is in a normalized state, the elongation rate is controlled at 1.6%, the insertion amount of the tension leveling roller is set to 25 / 25 / 15, and the tension mode of the tension leveling machine is used when the weld passes through the tension leveling machine;

[0061] When the steel plate is in an abnormal state, the elongation rate is controlled at 2.0%, the insertion amount of the tension leveling roller is set to 20 / 20 / 15, and the elongation rate mode is used when the weld passes through the tension leveling machine.

[0062] During the processing, based on the verification results of cupping and bending experiments, the elongation and insertion amount were finely adjusted in conjunction, and the steel plate successfully passed through the phosphorus-breaking straightening machine without any strip breakage.

[0063] In this embodiment, after adopting the method of the present invention, there is no impact or jamming of the strip head and tail during the production process of this grade of steel coil, no problem of false welding, the frequency of strip breakage is reduced by more than 90%, the pass rate of strip steel surface quality is increased to more than 99.5%, and at the same time, the cost of roll replacement and maintenance is greatly reduced, and the equipment downtime and manual intervention costs are reduced.

[0064] Example 2:

[0065] This embodiment is designed for continuous coil changing production of high-grade and low-grade steel coils, and adopts the present invention as follows: Figure 1 The processing method shown is as follows, and the specific implementation steps are as follows:

[0066] S1. Straightening pretreatment of the front and rear ends: For 60-meter lengths of steel plates with the tail of the preceding high-grade steel coil and the head of the following low-grade steel coil, straightening pretreatment is performed according to the corresponding grade and straightening parameters are matched to eliminate the upturning defects of the front and rear ends.

[0067] S2. Welding Process: Due to the large difference in grades between the preceding and following steel coils, the rolling force difference exceeds the preset threshold. W440 medium-grade steel coils are used as transition material. First, the tail of the preceding high-grade steel coil is welded to the head of the transition material, and then the tail of the transition material is welded to the head of the following low-grade steel coil. During the welding process, the welding parameters corresponding to the thickness in Table 1 are matched, the welding speed is controlled at 3.5m / min, and the laser power is controlled at 5.0KW to ensure the weld strength. After welding, the anti-wrinkle rollers are not used during the steel plate release process.

[0068] S3. Weld quality verification: The quality of the two welds is verified separately. The weld between the high grade and the transition material is only subjected to cupping test, while the weld between the transition material and the low grade is subjected to cupping test and bending test in sequence. The weld is released after both welds are verified to be qualified.

[0069] S4. Phosphorus Removal and Straightening Process: For steel coil grade switching, the elongation patterns corresponding to low, medium, and high grades in Table 2 are matched sequentially, with the elongation control range being 0.8%-2.0%. Simultaneously, based on the grade and silicon content of each section of the steel coil, the insertion amount of the phosphorus removal and straightening rollers is adjusted accordingly, with a smaller insertion amount used for high-silicon sections. During processing, based on weld quality verification results, the elongation and insertion amount of the weld as it passes through the phosphorus removal and straightening machine are slightly reduced to ensure stable weld passage.

[0070] In this embodiment, after adopting the method of the present invention, there are no steel jams, no false welds, and no strip breaks during the production process of changing high and low grade coils. The coil changing process does not require machine shutdown and manual intervention, which greatly improves production efficiency, and the surface quality of the steel plate in the transition section meets the product standard requirements.

[0071] Example 3:

[0072] This embodiment focuses on the continuous cold rolling production of SG50W600 grade low-grade non-oriented electrical steel sheets, employing the present invention as follows: Figure 1 The processing method shown is as follows, and the specific implementation steps are as follows:

[0073] S1. Head and Tail Straightening Pretreatment: The steel plate with a head and tail of 60 meters is straightened and pretreated by the inlet straightening machine. The straightening machine parameters are matched and set according to the characteristics of SG50W600 grade to eliminate the plate shape defects with head and tail.

[0074] S2. Welding process: Weld the front and rear ends of the same grade SG50W600 steel coils. The steel plate thickness is 2.3mm. Match the basic welding parameters corresponding to 35W440 in Table 1. The laser power is controlled at 4.0KW and the welding speed is controlled at 5.0m / min to ensure the quality of the weld formation. During the release of the steel plate after welding, the anti-wrinkle roller is not used.

[0075] S3. Weld quality verification: The weld is subjected to cupping test and bending test in sequence. It is released after the verification is qualified.

[0076] S4. Phosphorus-breaking straightening process: Match the process parameters corresponding to the lower grades in Table 2, control the elongation rate to 2.3%±0.03%, set the straightening roller insertion amount to 25 / 25 / 15, and put the straightening machine into normal operation when the weld passes through the straightening machine.

[0077] In this embodiment, the steel plate passes through the production line smoothly without any jamming or strip breakage. The strip surface exhibits excellent phosphorus removal effect, and the plate straightness meets product standard requirements. The production efficiency is increased by more than 15% compared to the traditional process.

[0078] Example 4:

[0079] This embodiment focuses on the continuous cold rolling production of SG50W310 high-grade non-oriented electrical steel sheets, with a silicon content of 2.6% (or less than 2.8%). The invention is employed as described above. Figure 1 The processing method shown is as follows, and the specific implementation steps are as follows:

[0080] S1. Straightening pretreatment of the front and rear ends: The steel plate with a length of 60 meters of front and rear ends of the steel coil of this grade is straightened and pretreated by the inlet straightening machine. The straightening parameters are matched to the high yield strength characteristics to eliminate the defects of the front and rear ends.

[0081] S2. Welding Process: The front and rear steel coils are made of the same grade of high-grade steel plate. The difference in rolling force exceeds the preset threshold. W440 medium-grade steel coil is used as the transition material for welding connection. The welding process matches the welding parameters corresponding to 35W300GL (WV2000) in Table 1. The steel plate thickness is 2.3mm. MG-50T welding wire with a diameter of 0.9mm is selected. The laser power is controlled at 4.2KW, the welding speed is 4.8m / min, the wire feed speed is 2.2m / min, the GAP is set to 0mm, and the linear energy is 525J / cm to ensure the weld strength. After welding, the anti-wrinkle roller is not used.

[0082] S3. Weld quality verification: For high-grade welds, only cupping test is performed. For transition section welds, cupping test and bending test are performed in sequence. All welds are released after verification.

[0083] S4. Phosphorus-breaking tension straightening process: Match the process parameters corresponding to the high grade (silicon content within 2.8%) in Table 2, control the elongation rate to 0.50%, set the tension straightening roller insertion amount to 10 / 10 / 15, and do not use the tension straightening machine when the weld passes through the tension straightening machine, and operate in the tension mode set by the second level.

[0084] In this embodiment, there is no strip breakage during the production of high silicon high yield strength steel plate, and the weld seam does not crack or deform when passing through the tension leveler. The plate surface quality meets the technical requirements of high grade products, and the strip breakage rate is reduced by more than 95% compared with the traditional process.

[0085] Example 5:

[0086] This embodiment focuses on the continuous cold rolling production of SG35W440 grade ultra-thin electrical steel sheets, employing the present invention as follows: Figure 1 The processing method shown is as follows, and the specific implementation steps are as follows:

[0087] S1. Head and Tail Straightening Pretreatment: The steel plate with a length of 60 meters from the head to the tail of the ultra-thin strip is straightened and pretreated by the inlet straightening machine. Low-stress straightening parameters are matched to the characteristics of the ultra-thin strip to avoid strip deformation during the straightening process.

[0088] S2. Welding Process: Weld the beginning and end of the same grade SG35W440 steel coils. The steel plate thickness is 2.3mm. Use MG-50T welding wire with a diameter of 0.9mm. Match the welding parameters corresponding to 35W440 in Table 1. The laser power is controlled at 3.5KW, the welding speed is 5.3m / min, the wire feed speed is 2.2m / min, the GAP is set to 0mm, and the linear energy is 396J / cm. To adjust the parameters according to the needs of the on-site working conditions, it can be switched to a combination of laser power 4.0KW, welding speed 3.0m / min, and GAP 0.1mm to adapt to different welding environments. After welding, the anti-wrinkle roller is not used.

[0089] S3. Weld quality verification: The weld is subjected to cupping test and bending test in sequence. It is released after the verification is qualified.

[0090] S4. Phosphorus breaking and straightening process: Match the process parameters corresponding to the ultra-thin strip in Table 2, control the elongation rate to 0.6%, and set the straightening roller insertion amount to 10 / 10 / 15 to ensure the shape of the ultra-thin strip while avoiding strip breakage.

[0091] In this embodiment, there is no tearing or breakage during the production of ultra-thin strip steel, and the plate surface is free of scratches and shape defects, resulting in a higher product qualification rate compared to traditional processes.

[0092] The present invention also provides a system for improving the surface quality of steel coils and reducing strip breakage, the system being used to achieve the above-mentioned... Figure 1 The methods shown for improving the surface quality of steel coils and reducing strip breakage include... Figure 2 As shown, the system includes a welding execution module, a phosphorus breaking and straightening execution module, and a process control module.

[0093] The welding execution module is used to complete the welding and fixing of the tail of the preceding steel coil and the head of the subsequent steel coil, realize the process connection of continuous steel coil production, and perform the relevant operations of the aforementioned welding process S2.

[0094] The phosphorus removal and straightening execution module is used to apply a combination of tensile and bending plastic deformation to the welded steel plate to complete the phosphorus removal and plate straightening process of the steel plate and execute the relevant operations of the aforementioned phosphorus removal and straightening process S4.

[0095] The process control module is communicatively connected to the welding execution module and the phosphorus removal and straightening execution module. The process control module has a built-in grade-elongation matching database and a grade-silicon content-straightening roll insertion amount matching database. The process control module is configured to: retrieve the grade information of the steel plate to be processed when the phosphorus removal and straightening execution module is operating, match and output the corresponding elongation control parameters to the phosphorus removal and straightening execution module, and simultaneously retrieve the grade and silicon content information of the steel plate to be processed, match and output the corresponding straightening roll insertion amount control parameters to the phosphorus removal and straightening execution module.

[0096] In the preferred embodiment of the system, the process control module also has a built-in welding parameter matching database and weld quality judgment rule library. It can match and output welding speed and welding power control parameters to the welding execution module according to the steel plate grade. At the same time, it can receive weld quality inspection data, complete the automatic judgment of weld quality based on the built-in rule library, and output the linkage fine adjustment command of elongation and insertion amount to the phosphorus breaking and straightening execution module according to the judgment result, so as to realize the automation and intelligent control of the whole process.

[0097] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0098] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0099] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The functions specified in one or more boxes. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0100] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for improving the surface quality of steel coils and reducing strip breakage, used in the continuous production and processing of high yield strength steel plates, characterized in that, This includes the sequential execution of welding and phosphorus-removing straightening processes; The welding process involves welding and fixing the tail of the preceding steel coil to the head of the following steel coil, thereby achieving continuous production of steel coils. The phosphorus-breaking and straightening process involves performing a combination of stretching and bending plastic deformation on the welded steel plate. During the process, the elongation rate of the steel plate is controlled according to its grade, and the insertion amount of the phosphorus-breaking and straightening rollers is adjusted according to the grade and silicon content of the steel plate.

2. The method for improving the surface quality of steel coils and reducing strip breakage according to claim 1, characterized in that, In the welding process, the welding speed is controlled at 3.0-6.0 m / min, and the welding power is controlled at 3.5-5.5 KW.

3. The method for improving the surface quality of steel coils and reducing strip breakage according to claim 1, characterized in that, After the welding process is completed, a quality verification experiment is conducted on the weld. The quality verification experiment includes a cupping test and a bending test. For high-grade steel plates, only the cupping test is conducted.

4. The method for improving the surface quality of steel coils and reducing strip breakage according to claim 3, characterized in that, When producing high-grade steel plates, if the difference in rolling force between the front and rear steel coils exceeds a preset threshold, medium-grade steel coils are used as transition material for welding connection.

5. The method for improving the surface quality of steel coils and reducing strip breakage according to claim 1, characterized in that, In the phosphorus breaking and straightening process, corresponding elongation modes are matched for steel coils of different grades (low, medium, and high), and the elongation control range of the steel plate is 0.5%-2.3%.

6. The method for improving the surface quality of steel coils and reducing strip breakage according to claim 1, characterized in that, In the phosphorus-removing and straightening process, the higher the silicon content of the steel plate, the smaller the gradient of the insertion amount of the phosphorus-removing and straightening rollers should be to avoid brittle fracture of the high-silicon steel plate.

7. The method for improving the surface quality of steel coils and reducing strip breakage according to claim 1, characterized in that, After the welding process is completed, the anti-wrinkle roller is not used during the process of releasing the steel plate into the subsequent processes.

8. The method for improving the surface quality of steel coils and reducing strip breakage according to claim 1, characterized in that, Before the welding process, a pre-treatment process for straightening the head and tail of the steel coil is set up to straighten the steel plate of the preset length at the head and tail. The straightening parameters are set according to the steel plate grade to eliminate the upturning defect at the head and tail.

9. The method for improving the surface quality of steel coils and reducing strip breakage according to claim 1, characterized in that, In the phosphorus breaking and straightening process, based on the weld quality verification results of the welding process, the elongation of the steel plate and the insertion amount of the phosphorus breaking and straightening roller are finely adjusted in conjunction to ensure that the weld does not break when passing through the phosphorus breaking and straightening process.

10. A system for improving the surface quality of steel coils and reducing strip breakage, used in the continuous production and processing of high yield strength steel plates, characterized in that, It includes a welding execution module, a phosphorus breaking and straightening execution module, and a process control module; The welding execution module is used to complete the welding and fixing of the tail of the preceding steel coil and the head of the subsequent steel coil, so as to realize the process connection of continuous steel coil production. The phosphorus-breaking and straightening execution module is used to apply a combination of tensile and bending plastic deformation to the welded steel plate to complete the phosphorus-breaking and plate straightening process of the steel plate. The process control module is communicatively connected to the welding execution module and the phosphorus removal and straightening execution module. The process control module has a built-in grade-elongation matching database and a grade-silicon content-straightening roll insertion amount matching database. The process control module is configured to: when the phosphorus removal and straightening execution module is operating, retrieve the grade information of the steel plate to be processed, match and output the corresponding elongation control parameters to the phosphorus removal and straightening execution module, and simultaneously retrieve the grade and silicon content information of the steel plate to be processed, match and output the corresponding straightening roll insertion amount control parameters to the phosphorus removal and straightening execution module.

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