Strip threading method for high-grade non-oriented silicon steel

Abstract

The invention discloses a threading method for high-grade non-oriented silicon steel. The threading method comprises the following steps that S1, a high-grade non-oriented silicon steel coil subjected to normal acid pickling is selected; s2, the high-grade non-oriented silicon steel coil is subjected to electromagnetic induction heating to the optimal rolling temperature and then is threaded to a coiling machine, and auxiliary coiling is completed; and S3, all the used racks are pressed down, an automatic thickness control module is closed, a rolling mill is started, and a staged and speed-divided control strategy is adopted. According to the invention, a mode of simultaneously pressing down and starting threading of the racks is adopted, so that high-grade non-oriented high-grade silicon steel is realized, and the purpose of quick starting is achieved.

Description

Technical Field

[0001] This invention relates to a silicon steel strip rolling technology, specifically to a strip rolling method for high-grade non-oriented silicon steel, and more particularly to a method for simultaneously pressing down and starting the strip rolling process on all stands of a six-stand, six-roll UCMW continuous rolling mill. Background Technology

[0002] Continuous rolling mills (including 4-high, 6-high, and 18-high configurations) are widely used in the cold rolling industry due to their numerous advantages, such as high production efficiency, low production cost, and strong shape control capabilities. With the continuous improvement of rolling technology, control strategies, and equipment levels, the use of continuous rolling mills to produce non-oriented high-grade silicon steel has become an industry trend.

[0003] The production of non-oriented high-grade silicon steel using a continuous rolling mill employs a continuous rolling mode. However, during the production process, there will inevitably be instances where the original sheet is threaded through the rolling mill for startup. Due to the high silicon content and coarse grains of non-oriented high-grade silicon steel, it exhibits high cold brittleness, making it highly susceptible to strip breakage and startup failure during the initial threading process. Currently, the mainstream startup method for high-grade non-oriented high-grade silicon steel in the industry is sequential stand-by-stand pressing startup. However, this method is time-consuming, inefficient, and cannot achieve automated startup. Simultaneous pressing startup across all stands has not yet been implemented.

[0004] The following information pertains to the original plate threaded start-up technology for similar units: Chinese Patent Application No.

[0005] CN202211191196.8 provides a rolling method for producing non-oriented silicon steel slabs with a silicon-aluminum content of 3.5-5% using a UCMW continuous rolling mill. This method uses a continuous rolling mill and sets appropriate rolling processes for stands 1 through 5, employing a sequential pressing start rolling process to ultimately achieve the strip-start rolling of non-oriented silicon steel slabs. However, this method has a long start-up time, low efficiency, requires on-site operation confirmation by multiple operators, and cannot achieve automated start-up. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for threading high-grade non-oriented silicon steel. This method employs a simultaneous pressing down of the machine frame to initiate threading, thereby achieving rapid start-up of high-grade non-oriented silicon steel.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention provides a method for threading high-grade non-oriented silicon steel, characterized by comprising the following steps:

[0009] S1, selected from high-grade non-oriented silicon steel coils that have undergone regular pickling;

[0010] S2, after the high-grade non-oriented silicon steel coil is electromagnetically induction heated to the optimal rolling temperature, it is threaded onto the coiler to complete the coiling process;

[0011] S3 involves pressing down all the stands, shutting down the automatic thickness control module, starting the mill, and adopting a phased and speed-based control strategy.

[0012] Preferably, in step S1, the silicon-aluminum content of the high-grade non-oriented silicon steel is 3.5-5 wt%, and the thickness before cold rolling is 1.6 mm-2.6 mm.

[0013] Preferably, in step S2, the optimal rolling temperature during the electromagnetic induction heating process is:

[0014] T = t + δT

[0015] In the formula, T is the optimal rolling temperature, in °C;

[0016] t represents the ambient temperature, in °C;

[0017] δT is the temperature rise value, which ranges from 0 to 250℃.

[0018] Preferably, the optimal rolling temperature is 40–250°C.

[0019] Preferably, step S3 specifically includes the following steps:

[0020] S31, all racks are pressed down simultaneously according to the process settings;

[0021] S32, the actual rolling force of each stand is controlled according to the material of non-oriented silicon steel;

[0022] S33: After starting the rolling mill, a phased and speed-controlled strategy is adopted. The starting speed is V0, and the bending roll value and tilt value are adjusted according to the shape of the plate. After all the stands have normal plate shape, the rolling mill speeds up to V1 and starts the emulsion spraying. After the finished plate shape is normal, the rolling mill speeds up to V2 and starts the automatic thickness control module. After the finished thickness is qualified and the plate shape is normal, the rolling mill speeds up to V3 and starts normal production.

[0023] Preferably, in step S32, the actual rolling force of each stand is as follows:

[0024] P 实际 =P 设定 ×(1+α)

[0025] In the formula, P 实际 Actual rolling force;

[0026] P 设定 Set the rolling force;

[0027] α, material coefficient, which is usually taken as 0 to 0.2.

[0028] Preferably, in step S33, the mill speed is set as follows:

[0029] The mill start-up speed V0 is selected to be 10m / min to 40m / min;

[0030] The target speed V1 for the first stage is selected as 50m / min to 80m / min;

[0031] The target speed V2 for the second stage is selected to be 90m / min to 200m / min;

[0032] For normal production speed, V3 is selected at ≥200m / min.

[0033] The threading method for high-grade non-oriented silicon steel provided by this invention also has the following beneficial effects:

[0034] Compared with the existing sequential rolling method, the threading method for high-grade non-oriented silicon steel of the present invention adopts a method of simultaneous rolling start-up across the entire stand, which has significant advantages. The method of the present invention has a fast start-up speed and high efficiency, and can complete the start-up of high-grade non-oriented silicon steel within 3 minutes, thereby achieving the goal of increasing production capacity and reducing costs. Attached Figure Description

[0035] Figure 1 This is a schematic flowchart of the threading method for high-grade non-oriented silicon steel according to the present invention. Detailed Implementation

[0036] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0037] This invention provides a method for threading high-grade non-oriented silicon steel, specifically for use in a six-stand, six-roll UCMW continuous rolling mill where all stands are simultaneously pressed down to start threading, thereby achieving rapid start-up of high-grade non-oriented silicon steel.

[0038] Combination Figure 1 As shown, the present invention provides a method for threading high-grade non-oriented silicon steel, comprising the following steps:

[0039] S1, selected from high-grade non-oriented silicon steel coils that have undergone regular pickling;

[0040] High-grade non-oriented silicon steel coils that have undergone normalizing and pickling are selected. The silicon and aluminum content of this high-grade non-oriented silicon steel is 3.5-5 wt%, and the thickness before cold rolling is 1.6 mm-2.6 mm.

[0041] S2, after the high-grade non-oriented silicon steel coil is electromagnetically induction heated to the optimal rolling temperature, it is threaded onto the coiler to complete the coiling process;

[0042] The electromagnetic induction heater is selected and used according to different strip steel materials and ambient temperature t. Different heating temperatures δT are selected to heat the strip steel to the optimal rolling temperature T. The heated strip steel is then threaded into the coiler to complete the coiling process.

[0043] The optimal rolling temperature during electromagnetic induction heating is:

[0044] T = t + δT

[0045] In the formula, T is the optimal rolling temperature, in °C. The optimal rolling temperature varies depending on the material of the strip. For non-oriented high-grade strips, the optimal rolling temperature is usually 40 to 250 °C.

[0046] t represents the ambient temperature, in °C;

[0047] δT is the temperature rise value, which ranges from 0 to 250℃ and can also be adjusted according to the actual situation.

[0048] S3 involves pressing down all the stands, shutting down the automatic thickness control module, and disabling control of the emulsion system; starting the mill and adopting a phased and speed-based control strategy.

[0049] Specifically, the following steps are included:

[0050] S31, all racks are pressed down simultaneously according to the process settings;

[0051] S32, the actual rolling force of each stand is controlled according to the material of non-oriented silicon steel;

[0052] Manually apply rolling force. Based on the set rolling force, use different material coefficients according to the material of the strip to increase the actual rolling pressure. The specific calculation formula for the actual rolling force of each stand is as follows;

[0053] P 实际 =P 设定 ×(1+α)

[0054] In the formula, P 实际 Actual rolling force;

[0055] P 设定 Set the rolling force;

[0056] α, material coefficient, is usually taken as 0 to 0.2, but can also be adjusted according to the actual situation.

[0057] S33: After starting the rolling mill, a phased and speed-controlled strategy is adopted. The starting speed is V0. After starting, the bending roll value and tilt value are adjusted according to the actual plate shape. After all stands have normal plate shape, the rolling mill speeds up to V1 and starts emulsion spraying. After the finished plate shape is normal, the rolling mill speeds up to V2 and starts the automatic thickness control module. After the finished thickness is qualified and the plate shape is normal, the rolling mill speeds up to V3 and starts normal production.

[0058] The above rolling mill speed settings are as follows:

[0059] The mill start-up speed V0 is selected to be 10m / min to 40m / min;

[0060] The target speed V1 for the first stage is selected as 50m / min to 80m / min;

[0061] The target speed V2 for the second stage is selected as 90m / min to 200m / min;

[0062] The normal production speed V3 is selected to be ≥200m / min.

[0063] In the initial stage, if the shape of the rack panels is not entirely normal, the actual panel shape needs to be manually adjusted to be normal before proceeding to the first stage. In the first stage, if the shape of the rack panels is not entirely normal, the actual panel shape needs to be manually adjusted to be normal before proceeding to the second stage. In the second stage, if the thickness and shape of the finished product do not meet the requirements, manual intervention is required to adjust them so that the shape and thickness of the finished product are normal.

[0064] Example 1

[0065] The threading method for high-grade non-oriented silicon steel in this embodiment includes the following steps:

[0066] (1) Select non-oriented high-grade silicon steel coils that have undergone normalizing and pickling, with a silicon-aluminum content of 3.8% and a thickness of 2.45 mm before cold rolling;

[0067] (2) When selecting an electromagnetic induction heater, the current ambient temperature is 35℃. According to the material of the strip steel, the heating temperature δT is selected as 165℃. The strip steel is heated to the optimal rolling temperature T to 200℃. The strip steel is then threaded into the coiler from the heating zone to complete the coiling process.

[0068] (3) With all frames fully depressed and the automatic thickness control module turned off, the emulsion system is not put into control:

[0069] ① All frames are pressed down simultaneously according to the process settings;

[0070] ② Manually increase the rolling force. Based on the set rolling force, select 0.15 according to the material coefficient α of the strip steel, so that the actual rolling force of each stand is 180 tons greater than the set rolling force.

[0071] ③ Adopt a phased and speed-based control strategy. The starting speed is set to V0 = 40 m / min. After starting, adjust the bending roll value and tilt value according to the actual plate shape. After all the frames have normal plate shape, the mill speed is increased to V1 = 70 m / min, and the emulsion spraying is started. After the finished plate shape is normal, the mill speed is increased to V2 = 120 m / min, and the automatic thickness control module is started. After the finished thickness is qualified and the plate shape is normal, the mill speed is increased to V3 = 200 m / min, and normal production begins.

[0072] This embodiment successfully achieved simultaneous pressing down of the entire frame to start the tape threading process, with no tape breakage throughout.

[0073] Example 2

[0074] The threading method for high-grade non-oriented silicon steel in this embodiment includes the following steps:

[0075] (1) Select non-oriented high-grade silicon steel coils that have undergone normalizing and pickling, with a silicon-aluminum content of 3.6% and a thickness of 1.8 mm before cold rolling;

[0076] (2) When selecting and using an electromagnetic induction heater, the current ambient temperature is 20℃. According to the material of the strip steel, the heating temperature δT is selected as 100℃. The strip steel is heated to the optimal rolling temperature T to 120℃. The strip steel is then threaded into the coiler from the heating zone to complete the coiling process.

[0077] (3) With all frames fully depressed and the automatic thickness control module turned off, the emulsion system is not put into control:

[0078] ① All frames are pressed down simultaneously according to the process settings;

[0079] ② Manually increase the rolling force. Based on the set rolling force, select 0.05 according to the material coefficient α of the strip steel, so that the actual rolling force of each stand is 60 tons greater than the set rolling force.

[0080] ③ Adopt a phased and speed-based control strategy. The starting speed is set to V0 = 30 m / min. After starting, adjust the bending roll value and tilt value according to the actual plate shape. After all the frames have normal plate shape, the mill speed is increased to V1 = 60 m / min, and the emulsion spraying is started. After the finished plate shape is normal, the mill speed is increased to V2 = 150 m / min, and the automatic thickness control module is started. After the finished thickness is qualified and the plate shape is normal, the mill speed is increased to V3 = 300 m / min, and normal production begins.

[0081] This embodiment successfully achieved simultaneous pressing down of the entire frame to start the tape threading process, with no tape breakage throughout.

[0082] In summary, this invention is designed to reduce product costs, improve product quality, meet product process control requirements, improve the on-site environment, and ensure stable production operation. It includes a full-stand press start-up procedure, electromagnetic induction heater temperature control, rolling force adjustment formula, and staged speed control. It has broad market prospects in the field of cold rolling of special steel, stainless steel, and silicon steel, and can also be promoted and used in other units with similar production conditions.

[0083] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A method for threading high-grade non-oriented silicon steel, characterized in that, Includes the following steps: S1, selected from high-grade non-oriented silicon steel coils that have undergone regular pickling; S2, after the high-grade non-oriented silicon steel coil is electromagnetically induction heated to the optimal rolling temperature, it is threaded onto the coiler to complete the coiling process; S3 involves pressing down all the stands, shutting down the automatic thickness control module, starting the mill, and adopting a phased and speed-based control strategy.

2. The method for threading high-grade non-oriented silicon steel according to claim 1, characterized in that: In step S1, the silicon-aluminum content of the high-grade non-oriented silicon steel is 3.5-5 wt%, and the thickness before cold rolling is 1.6 mm-2.6 mm.

3. The method for threading high-grade non-oriented silicon steel according to claim 1, characterized in that: In step S2, during the electromagnetic induction heating process, the optimal rolling temperature is: T = t + δT In the formula, T is the optimal rolling temperature, in °C; t represents the ambient temperature, in °C; δT is the temperature rise value, which ranges from 0 to 250℃.

4. The method for threading high-grade non-oriented silicon steel according to claim 3, characterized in that: The optimal rolling temperature is 40–250°C.

5. The method for threading high-grade non-oriented silicon steel according to claim 1, characterized in that: Step S3 specifically includes the following steps: S31, all racks are pressed down simultaneously according to the process settings; S32, the actual rolling force of each stand is controlled according to the material of non-oriented silicon steel; S33: After starting the rolling mill, a phased and speed-controlled strategy is adopted. The starting speed is V0, and the bending roll value and tilt value are adjusted according to the shape of the plate. After all the stands have normal plate shape, the rolling mill speeds up to V1 and starts the emulsion spraying. After the finished plate shape is normal, the rolling mill speeds up to V2 and starts the automatic thickness control module. After the finished thickness is qualified and the plate shape is normal, the rolling mill speeds up to V3 and starts normal production.

6. The method for threading high-grade non-oriented silicon steel according to claim 5, characterized in that: In step S32, the actual rolling force of each stand is as follows: P 实际 =P 设定 ×(1+α) In the formula, P 实际 Actual rolling force; P 设定 Set the rolling force; α, material coefficient, which is usually taken as 0 to 0.

2.

7. The method for threading high-grade non-oriented silicon steel according to claim 5, characterized in that: In step S33, the mill speed is set as follows: The mill start-up speed V0 is selected to be 10m / min to 40m / min; The target speed V1 for the first stage is selected as 50m / min to 80m / min; The target speed V2 for the second stage is selected as 90m / min to 200m / min; The normal production speed V3 is selected to be ≥200m / min.

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