A method for coordinated control of hot and cold rolling to reduce the difference between non-oriented silicon steel sheets

Abstract

The present invention discloses a method for coordinated hot and cold rolling control to reduce the cross-sheet variation of non-oriented silicon steel, belonging to the technical field of non-oriented silicon steel rolling. The present invention optimizes and improves the cold-rolled finished product profile of non-oriented silicon steel by coordinatedly controlling the matching of the hot-rolled profile and the cold-rolled profile. Through the implementation of this method, the transverse cross-sheet variation of the cold-rolled strip is reduced to 4 to 8 μm, compared to the 10 to 15 μm cross-sheet variation of hot-rolled strip in the prior art. This method meets the requirements for producing high-end non-oriented silicon steel products and improves the quality and yield rate of the cold-rolled strip.

Description

Technical Field

[0001] The present invention belongs to the technical field of non-oriented silicon steel rolling, and in particular relates to a method for coordinated control of hot and cold rolling to reduce the same-plate difference of non-oriented silicon steel. Background Art

[0002] With the continuous advancement of non-oriented silicon steel production technology, users have increasingly high expectations for the flatness quality of finished non-oriented silicon steel products. Good cross-strip tolerance can significantly enhance the added value of high-quality non-oriented silicon steel products. However, the production process of non-oriented silicon steel is complex and lengthy. Hot and cold rolling processes have the greatest impact on cross-strip tolerance. Poor cross-strip tolerance control of hot-rolled products directly impacts the cross-strip tolerance quality of downstream processes such as cold rolling. Domestic cross-strip tolerance for hot-rolled strip ranges from 0.025 to 0.04 mm. Reducing the transverse cross-strip tolerance of hot-rolled strip is key to improving the quality of cold-rolled strip. Hot-rolled strip with large cross-strip tolerances leads to low cold-rolling yields in subsequent production. Therefore, optimizing and improving the cross-strip shape of cold-rolled non-oriented silicon steel products can be achieved by collaboratively controlling the hot-rolled and cold-rolled rolling modes. Summary of the Invention

[0003] In order to solve the problem of poor same-plate difference of non-oriented silicon steel finished products, the purpose of the present invention is to provide a hot and cold rolling coordinated control method for reducing the same-plate difference of non-oriented silicon steel, so as to optimize and improve the plate shape of non-oriented silicon steel cold-rolled finished products.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The present invention provides a hot and cold rolling coordinated control method for reducing the same plate difference of non-oriented silicon steel, comprising:

[0006] The hot rolling production process of non-oriented silicon steel adopts thin slab continuous casting and rolling method. Before hot rolling, the slab is heated to the hot rolling start temperature of 1040-1080℃ in a tunnel furnace. The furnace pressure in the heating furnace is set at 20-23Pa, and the maximum temperature difference in the thickness and width directions of the slab is kept within ±20℃.

[0007] The hot rolling adopts a seven-stand continuous rolling process. The hot rolling rolls are selected with small roll crown. The working roll crown of the hot rolling roll is 50-100μm. The variable crown of the hot rolling CVC roll is adjusted according to different rolling stages. The variable crown range is -80-100μm.

[0008] Different tension adjustments are made for hot-rolled products of different thicknesses. For hot-rolled products with a thickness greater than 2.8mm, the strip tension increases by 1.2%-1.5%; for hot-rolled products with a thickness greater than 2.75mm and less than 2.8mm, the strip tension increases by 5%-8%; for hot-rolled products with a thickness greater than 2.65mm and less than 2.75mm, the strip tension increases by 12%-16%; for hot-rolled products with a thickness greater than 2.5mm and less than 2.65mm, the strip tension increases by 17%-20%; for hot-rolled products with a thickness less than 2.5mm, the strip tension increases by 21%-25%;

[0009] The cold rolling adopts a six-high five-stand continuous rolling mill, and the cold rolling mode is matched based on the hot rolling results of small crown plate;

[0010] Selection of roller type: To improve the ability of the rolling mill to control edge drop during the cold rolling of silicon steel, the first two stands F1 and F2 are adjusted to tapered rollers with a cubic curve on the roller surface;

[0011] Roll shifting amount for cold rolling: F1 intermediate roll shifting amount is 60-80mm; F2 intermediate roll shifting amount is 50-60mm;

[0012] Bending force of cold rolling work rolls: Bending force of work rolls of each stand F1: 310-320KN; F2: 320-330KN; F3-F5: 350-700KN;

[0013] Cold rolling tension: F1-F2: 150-170MPa; F2-F3: 180-200MPa; F3-F4: 220-240MPa; F4-F5: 210-230MPa.

[0014] Furthermore, the difference between hot-rolled finished plates is controlled within 15-30 μm.

[0015] Furthermore, the transverse thickness difference of cold-rolled strip is reduced to 4-8μm.

[0016] Furthermore, the hot rolling production process of non-oriented silicon steel adopts thin slab continuous casting and rolling method. Before hot rolling, the slab is heated to the hot rolling start temperature of 1050℃ in a tunnel furnace. The furnace pressure in the heating furnace is set to 20Pa, and the maximum temperature difference in the thickness and width directions of the slab is kept within ±20℃.

[0017] The hot rolling adopts a seven-stand continuous rolling process. The hot rolling rolls are selected with small roll crown. The working roll crown of the hot rolling roll is 60μm. The variable crown of the hot rolling CVC roll is adjusted according to different rolling stages, and the variable crown is 20μm.

[0018] Different tension adjustments are made for hot-rolled products of different thicknesses; for hot-rolled products with a thickness of 2.85mm, the strip tension is increased by 1.5%;

[0019] The cold rolling adopts a six-high five-stand continuous rolling mill, and the cold rolling mode is matched based on the hot rolling results of small crown plate;

[0020] Selection of roller type: To improve the ability of the rolling mill to control edge drop during the cold rolling of silicon steel, the first two stands F1 and F2 are adjusted to tapered rollers with a cubic curve on the roller surface;

[0021] Roll shifting amount for cold rolling: 75mm for F1 middle roll and 55mm for F2 middle roll.

[0022] Bending force of cold rolling work rolls: Bending force of each stand work roll F1: 315KN; F2: 325KN; F3-F5: 350-700KN;

[0023] Cold rolling tension: F1-F2: 156MPa; F2-F3: 186MPa; F3-F4: 230MPa; F4-F5: 213MPa.

[0024] Furthermore, the hot rolling production process of non-oriented silicon steel adopts thin slab continuous casting and rolling method. Before hot rolling, the slab is heated to the hot rolling start temperature of 1056℃ in a tunnel furnace. The furnace pressure in the heating furnace is set to 22Pa, and the maximum temperature difference in the thickness and width directions of the slab is kept within ±20℃.

[0025] The hot rolling adopts a seven-stand continuous rolling process. The hot rolling rolls are selected with small roll crown. The working roll crown of the hot rolling roll is 70μm. The variable crown of the hot rolling CVC roll is adjusted according to different rolling stages, and the variable crown is 30μm.

[0026] Different tension adjustments are made for hot-rolled products of different thicknesses; for hot-rolled products with a thickness of 2.67mm, the strip tension increases by 14%;

[0027] The cold rolling adopts a six-high five-stand continuous rolling mill, and the cold rolling mode is matched based on the hot rolling results of small crown plate;

[0028] Selection of roller type: To improve the ability of the rolling mill to control edge drop during the cold rolling of silicon steel, the first two stands F1 and F2 are adjusted to tapered rollers with a cubic curve on the roller surface;

[0029] Roll shifting amount for cold rolling: 60mm for F1 middle roll and 53mm for F2 middle roll.

[0030] Bending force of cold rolling work rolls: Bending force of each stand work roll F1: 313KN; F2: 325KN; F3-F5: 350-700KN;

[0031] Cold rolling tension: F1-F2: 153MPa; F2-F3: 186MPa; F3-F4: 223MPa; F4-F5: 216MPa.

[0032] Furthermore, the hot rolling production process of non-oriented silicon steel adopts thin slab continuous casting and rolling method. Before hot rolling, the slab is heated to the hot rolling start temperature of 1045℃ in a tunnel furnace. The furnace pressure in the heating furnace is set to 22Pa, and the maximum temperature difference in the thickness and width directions of the slab is kept within ±20℃.

[0033] The hot rolling adopts a seven-stand continuous rolling process. The hot rolling rolls are selected with small roll crown. The working roll crown of the hot rolling roll is 80μm. The variable crown of the hot rolling CVC roll is adjusted according to different rolling stages, and the variable crown is 10μm.

[0034] Different tension adjustments are made for hot-rolled products of different thicknesses; for hot-rolled products with a thickness of 2.55, the strip tension increases by 18%;

[0035] The cold rolling adopts a six-high five-stand continuous rolling mill, and the cold rolling mode is matched based on the hot rolling results of small crown plate;

[0036] Selection of roller type: To improve the ability of the rolling mill to control edge drop during the cold rolling of silicon steel, the first two stands F1 and F2 are adjusted to tapered rollers with a cubic curve on the roller surface;

[0037] Roll shifting amount for cold rolling: F1 middle roll shifting amount is 73mm; F2 middle roll shifting amount is 53mm;

[0038] Bending force of cold rolling work rolls: Bending force of each stand work roll F1: 318KN; F2: 326KN; F3-F5: 350-700KN;

[0039] Cold rolling tension: F1-F2: 163MPa; F2-F3: 192MPa; F3-F4: 236MPa; F4-F5: 226MPa.

[0040] Compared with the prior art, the present invention has the following beneficial technical effects:

[0041] Through the implementation of this method, the transverse plate difference of cold-rolled strip is reduced to 4 to 8 μm, compared with the hot-rolled strip plate difference of 10 to 15 μm in the existing technology, which meets the demand for producing high-end non-oriented silicon steel products and improves the quality and yield of cold-rolled strip.

[0042] The present invention optimizes and improves the shape of the cold-rolled finished product of non-oriented silicon steel by collaboratively controlling the matching of the hot-rolled plate shape and the cold-rolled rolling mode. DETAILED DESCRIPTION

[0043] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Example 1

[0044] The hot rolling production process of non-oriented silicon steel adopts thin slab continuous casting and rolling method. Before hot rolling, the slab is heated to the hot rolling start temperature of 1050℃ in a tunnel furnace. The furnace pressure in the heating furnace is set to 20Pa, and the maximum temperature difference in the thickness and width directions of the slab is kept within ±20℃.

[0045] The hot rolling adopts a seven-stand continuous rolling process. The hot rolling roll type selects rolls with small roll crown, and the working roll crown of the hot rolling roll is 60μm. According to different rolling stages, the variable crown of the hot rolling CVC roll is adjusted, and the variable crown is 20μm.

[0046] Different tension adjustments are made for hot-rolled products of different thicknesses; for hot-rolled products with a thickness of 2.85mm, the strip tension is increased by 1.5%

[0047] The difference between hot-rolled finished plates is controlled within 25μm.

[0048] The cold rolling adopts a six-high five-stand continuous rolling mill, and the cold rolling mode is matched based on the hot rolling results of small crown plate.

[0049] Selection of roller type: To improve the ability of the rolling mill to control edge drop during the cold rolling of silicon steel, the first two stands F1 and F2 are adjusted to tapered rollers with a cubic curve on the roller surface;

[0050] Roll shifting amount for cold rolling: 75mm for F1 middle roll and 55mm for F2 middle roll.

[0051] Bending force of cold rolling work rolls: Bending force of each stand work roll F1: 315KN; F2: 325KN; F3-F5: 350-700KN

[0052] Cold rolling tension: F1-F2: 156MPa; F2-F3: 186MPa; F3-F4: 230MPa; F4-F5: 213MPa.

[0053] Through the implementation of this method, the transverse plate difference of cold-rolled strip is reduced to 7μm, which meets the demand for producing high-end non-oriented silicon steel products and improves the quality and yield of cold-rolled strip. Example 2

[0054] The hot rolling production process of non-oriented silicon steel adopts thin slab continuous casting and rolling method. Before hot rolling, the slab is heated to the hot rolling start temperature of 1056℃ in a tunnel furnace. The furnace pressure in the heating furnace is set to 22Pa, and the maximum temperature difference in the thickness and width directions of the slab is kept within ±20℃.

[0055] The hot rolling adopts a seven-stand continuous rolling process. The hot rolling roll type selects rolls with small roll crown, and the working roll crown of the hot rolling roll is 70μm. According to different rolling stages, the variable crown of the hot rolling CVC roll is adjusted, and the variable crown is 30μm.

[0056] Different tension adjustments are made for hot-rolled products of different thicknesses; for hot-rolled products with a thickness of 2.67mm, the strip tension increases by 14%.

[0057] The difference between hot-rolled finished plates is controlled within 20μm.

[0058] The cold rolling adopts a six-high five-stand continuous rolling mill, and the cold rolling mode is matched based on the hot rolling results of small crown plate.

[0059] Selection of roller type: To improve the ability of the rolling mill to control edge drop during the cold rolling of silicon steel, the first two stands F1 and F2 are adjusted to tapered rollers with a cubic curve on the roller surface;

[0060] Roll shifting amount for cold rolling: 60mm for F1 middle roll and 53mm for F2 middle roll.

[0061] Bending force of cold rolling work rolls: Bending force of each stand work roll F1: 313KN; F2: 325KN; F3-F5: 350-700KN

[0062] Cold rolling tension: F1-F2: 153MPa; F2-F3: 186MPa; F3-F4: 223MPa; F4-F5: 216MPa.

[0063] Through the implementation of this method, the transverse plate difference of cold-rolled strip is reduced to 5μm, which meets the demand for producing high-end non-oriented silicon steel products and improves the quality and yield of cold-rolled strip. Example 3

[0064] The hot rolling production process of non-oriented silicon steel adopts thin slab continuous casting and rolling method. Before hot rolling, the slab is heated to the hot rolling start temperature of 1045℃ in a tunnel furnace. The furnace pressure in the heating furnace is set to 22Pa, and the maximum temperature difference in the thickness and width directions of the slab is kept within ±20℃.

[0065] The hot rolling adopts a seven-stand continuous rolling process. The hot rolling roll type selects rolls with small roll crown, and the working roll crown of the hot rolling roll is 80μm. According to different rolling stages, the variable crown of the hot rolling CVC roll is adjusted, and the variable crown is 10μm.

[0066] Different tension adjustments are made for hot-rolled products of different thicknesses; for hot-rolled products with a thickness of 2.55, the strip tension increases by 18%.

[0067] The difference between hot-rolled finished plates is controlled within 22μm.

[0068] The cold rolling adopts a six-high five-stand continuous rolling mill, and the cold rolling mode is matched based on the hot rolling results of small crown plate.

[0069] Selection of roller type: To improve the ability of the rolling mill to control edge drop during the cold rolling of silicon steel, the first two stands F1 and F2 are adjusted to tapered rollers with a cubic curve on the roller surface;

[0070] Roll shifting amount for cold rolling: F1 middle roll shifting amount is 73mm; F2 middle roll shifting amount is 53mm;

[0071] Bending force of cold rolling work rolls: Bending force of each stand work roll F1: 318KN; F2: 326KN; F3-F5: 350-700KN

[0072] Cold rolling tension: F1-F2: 163MPa; F2-F3: 192MPa; F3-F4: 236MPa; F4-F5: 226MPa.

[0073] Through the implementation of this method, the transverse plate difference of cold-rolled strip is reduced to 6μm, which meets the demand for producing high-end non-oriented silicon steel products and improves the quality and yield of cold-rolled strip.

[0074] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for coordinated control of hot and cold rolling to reduce the difference between the same sheets of non-oriented silicon steel, characterized by: include: The hot rolling production process of non-oriented silicon steel adopts thin slab continuous casting and rolling method. Before hot rolling, the slab is heated to the hot rolling start temperature of 1040-1080℃ in a tunnel furnace. The furnace pressure in the heating furnace is set at 20-23Pa, and the maximum temperature difference in the thickness and width directions of the slab is kept within ±20℃. The hot rolling adopts a seven-stand continuous rolling process. The hot rolling rolls are selected with small roll crown. The working roll crown of the hot rolling roll is 50-100μm. According to different rolling stages, the variable crown of the hot rolling CVC roll is adjusted, with a variable crown of -80-100μm; Different tension adjustments are made for hot-rolled products of different thicknesses. For hot-rolled products with a thickness greater than 2.8mm, the strip tension increases by 1.2%-1.5%; for hot-rolled products with a thickness greater than 2.75mm and less than 2.8mm, the strip tension increases by 5%-8%; for hot-rolled products with a thickness greater than 2.65mm and less than 2.75mm, the strip tension increases by 12%-16%; for hot-rolled products with a thickness greater than 2.5mm and less than 2.65mm, the strip tension increases by 17%-20%; for hot-rolled products with a thickness less than 2.5mm, the strip tension increases by 21%-25%; The cold rolling adopts a six-high five-stand continuous rolling mill, and the cold rolling mode is matched based on the hot rolling results of small crown plate; Selection of roller type: To improve the ability of the rolling mill to control edge drop during the cold rolling of silicon steel, the first two stands F1 and F2 are adjusted to tapered rollers with a cubic curve on the roller surface; Roll shifting amount for cold rolling: F1 middle roll shifting amount is 60-80mm; F2 middle roller shifting amount 50-60mm; Bending force of cold rolling work roll: Bending force of each stand work roll F1: 310-320KN; F2: 320-330KN; F3-F5: 350-700KN; Cold rolling tension: F1-F2: 150-170MPa; F2-F3: 180-200MPa; F3-F4: 220-240MPa; F4-F5: 210-230MPa.

2. The method for coordinated control of hot and cold rolling to reduce the sheet-to-sheet difference of non-oriented silicon steel according to claim 1, characterized in that: The difference between hot-rolled finished plates is controlled within 15-30μm.

3. The method for coordinated control of hot and cold rolling to reduce the sheet-to-sheet difference of non-oriented silicon steel according to claim 1, characterized in that: The transverse thickness difference of cold-rolled strip is reduced to 4-8μm.

4. The method for coordinated control of hot and cold rolling to reduce the sheet-to-sheet difference of non-oriented silicon steel according to claim 1, characterized in that: The hot rolling production process of non-oriented silicon steel adopts thin slab continuous casting and rolling method. Before hot rolling, the slab is heated to the hot rolling start temperature of 1050℃ in a tunnel furnace. The furnace pressure in the heating furnace is set to 20Pa, and the maximum temperature difference in the thickness and width directions of the slab is kept within ±20℃. The hot rolling adopts a seven-stand continuous rolling process. The hot rolling rolls are selected with small roll crown. The working roll crown of the hot rolling roll is 60μm. The variable crown of the hot rolling CVC roll is adjusted according to different rolling stages, and the variable crown is 20μm. Different tension adjustments are made for hot-rolled products of different thicknesses; The thickness of the hot-rolled finished product is 2.85 mm, and the strip tension is increased by 1.5%; The cold rolling adopts a six-high five-stand continuous rolling mill, and the cold rolling mode is matched based on the hot rolling results of small crown plate; Selection of roller type: To improve the ability of the rolling mill to control edge drop during the cold rolling of silicon steel, the first two stands F1 and F2 are adjusted to tapered rollers with a cubic curve on the roller surface; Roll shifting amount for cold rolling: 75mm for F1 middle roll and 55mm for F2 middle roll. Bending force of cold rolling work rolls: Bending force of each stand work roll F1: 315KN; F2: 325KN; F3-F5: 350-700KN; Cold rolling tension: F1-F2: 156MPa; F2-F3: 186MPa; F3-F4: 230MPa; F4-F5: 213MPa.

5. The method for coordinated control of hot and cold rolling to reduce the sheet-to-sheet difference of non-oriented silicon steel according to claim 1, characterized in that: The hot rolling production process of non-oriented silicon steel adopts thin slab continuous casting and rolling method. Before hot rolling, the slab is heated to the hot rolling start temperature of 1056℃ in a tunnel furnace. The furnace pressure in the heating furnace is set to 22Pa, and the maximum temperature difference in the thickness and width directions of the slab is kept within ±20℃. The hot rolling adopts a seven-stand continuous rolling process. The hot rolling rolls are selected with small roll crown. The working roll crown of the hot rolling roll is 70μm. The variable crown of the hot rolling CVC roll is adjusted according to different rolling stages, and the variable crown is 30μm. Different tension adjustments are made for hot-rolled products of different thicknesses; The thickness of the hot-rolled finished product is 2.67 mm, and the strip tension is increased by 14%; The cold rolling adopts a six-high five-stand continuous rolling mill, and the cold rolling mode is matched based on the hot rolling results of small crown plate; Selection of roller type: To improve the ability of the rolling mill to control edge drop during the cold rolling of silicon steel, the first two stands F1 and F2 are adjusted to tapered rollers with a cubic curve on the roller surface; Roll shifting amount for cold rolling: 60mm for F1 middle roll and 53mm for F2 middle roll. Bending force of cold rolling work rolls: Bending force of each stand work roll F1: 313KN; F2: 325KN; F3-F5: 350-700KN; Cold rolling tension: F1-F2: 153MPa; F2-F3: 186MPa; F3-F4: 223MPa; F4-F5: 216MPa.

6. The method for coordinated control of hot and cold rolling to reduce the sheet-to-sheet difference of non-oriented silicon steel according to claim 1, characterized in that: The hot rolling production process of non-oriented silicon steel adopts thin slab continuous casting and rolling method. Before hot rolling, the slab is heated to the hot rolling start temperature of 1045℃ in a tunnel furnace. The furnace pressure in the heating furnace is set to 22Pa, and the maximum temperature difference in the thickness and width directions of the slab is kept within ±20℃. The hot rolling adopts a seven-stand continuous rolling process. The hot rolling rolls are selected with small roll crown. The working roll crown of the hot rolling roll is 80μm. The variable crown of the hot rolling CVC roll is adjusted according to different rolling stages, and the variable crown is 10μm. Different tension adjustments are made for hot-rolled products of different thicknesses; The hot-rolled finished product has a thickness of 2.55 mm and the strip tension is increased by 18%; The cold rolling adopts a six-high five-stand continuous rolling mill, and the cold rolling mode is matched based on the hot rolling results of small crown plate; Selection of roller type: To improve the ability of the rolling mill to control edge drop during the cold rolling of silicon steel, the first two stands F1 and F2 are adjusted to tapered rollers with a cubic curve on the roller surface; Roll shifting amount for cold rolling: F1 middle roll shifting amount is 73mm; F2 middle roll shifting amount is 53mm; Bending force of cold rolling work rolls: Bending force of each stand work roll F1: 318KN; F2: 326KN; F3-F5: 350-700KN; Cold rolling tension: F1-F2: 163MPa; F2-F3: 192MPa; F3-F4: 236MPa; F4-F5: 226MPa.