Steel plate for intermittent drive motor and production method thereof

Abstract

The invention relates to the technical field of steel production, in particular to a steel plate for an intermittent drive motor, which comprises the following chemical components in percentage by mass: less than or equal to 0.003% of C, 0.50-1.50% of Si, 0.5-1.5% of Mn, 0.02-0.06% of P, less than or equal to 0.001% of S, less than or equal to 0.002% of N, 0.05-0.15% of Mo and 0.20-1.00% of Als. And the balance of Fe and inevitable residual elements. The electromagnetic performance requirement can be met, the mechanical strength machining performance can be considered, the operation efficiency and reliability of the intermittent drive motor are improved, and the production cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of steel production technology, and specifically relates to a method for producing steel plates for intermittent drive motors. Background Technology

[0002] Intermittent drive motors are miniature motors that periodically start and stop under specific operating conditions. They are widely used in various automated equipment, office supplies, small household appliances, and precision instruments, such as paper feeding mechanisms in printers, scanning drives in copiers, and intermittent motion devices in toys. One of their core components is the steel plates used for the motor rotor and stator; the performance of these steel plates directly affects the motor's operating efficiency, reliability, and service life.

[0003] Currently, the steel plates used in intermittent drive motors on the market are mostly ordinary silicon steel sheets or amorphous alloy materials, with thicknesses typically concentrated in the relatively thin range (e.g., 0.35mm to 0.5mm). However, with the increasing complexity and diversification of intermittent drive motor applications, especially for some special-purpose motors requiring high torque and high load capacity, thin steel plates are no longer sufficient to meet their performance requirements. Thicker steel plates, due to their higher mechanical strength and load capacity, are gradually becoming a new demand in the development of intermittent drive motors.

[0004] Thick steel plates offer significant advantages in the production of intermittent drive motors. Firstly, their greater thickness significantly enhances mechanical strength and load capacity, better enabling them to withstand the substantial mechanical stress and impact loads generated during frequent start-stop cycles, effectively preventing deformation and damage and extending the motor's lifespan. Secondly, thicker steel plates exhibit better dimensional stability, maintaining higher precision during processing and assembly, which is crucial for ensuring the motor's compact structure and overall performance. Furthermore, the smaller non-magnetic gaps between laminations in motors made from thicker steel plates result in superior starting torque. However, thicker steel plates also present some challenges in terms of electromagnetic performance, such as relatively higher hysteresis and eddy current losses. These issues require optimization of material composition and processing techniques. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for producing steel plates for intermittent drive motors, which solves the problem of electromagnetic performance of thick steel plates, while meeting the requirements of mechanical strength and processing performance.

[0006] To achieve the above objectives, the present invention employs the following technical solution: A steel plate for intermittent drive motor has the following chemical composition by mass fraction: C ≤ 0.003%, Si: 0.50%–1.50%, Mn: 0.5%–1.5%, P: 0.02%–0.06%, S ≤ 0.001%, N ≤ 0.002%, Mo: 0.05%–0.15%, Als: 0.20%–1.00%. The remainder is Fe and unavoidable residual elements.

[0007] A steel plate for an intermittent drive motor, the steel plate having a thickness of 1.0 mm to 3.0 mm.

[0008] A steel plate for intermittent drive motor, with the following mechanical properties: yield strength Rp0.2 in the range of 280MPa to 420MPa, and magnetic induction intensity ≥1.75T.

[0009] The chemical components function as follows: Carbon is one of the basic elements in steel, and its content has a significant impact on the properties of steel. The carbon content should be ≤0.003%. The main purpose of a low carbon content is to reduce hysteresis loss, because the presence of carbon increases the resistance to movement of magnetic domain walls, thereby increasing hysteresis loss.

[0010] The silicon content is set between 0.50% and 1.50%. The addition of silicon increases the resistivity of steel, thereby reducing eddy current losses. However, excessive silicon content can lead to a decrease in the toughness and processing performance of the steel, therefore its content range needs to be strictly controlled. Furthermore, silicon can also improve the oxidation resistance of steel to some extent, helping to extend the service life of the steel plate.

[0011] The manganese content is 0.5%–1.5%. Manganese can improve the strength and toughness of steel. Its main mechanism of action is through solid solution strengthening, increasing the hardness and tensile strength of steel. At the same time, manganese can also improve the hardenability of steel, allowing thick steel plates to achieve a more uniform distribution of properties during heat treatment. In addition, manganese has little effect on electromagnetic properties, thus improving the mechanical properties of steel without affecting electromagnetic properties.

[0012] Aluminum is set at 0.2% to 1.0%. Besides increasing resistivity, aluminum's main function is to improve the mechanical properties of steel.

[0013] The phosphorus content is controlled between 0.02% and 0.06%. As a solid solution strengthening element, phosphorus can significantly increase the resistivity of steel, thereby effectively reducing eddy current losses. Simultaneously, by refining grains and optimizing magnetic domain structure, it reduces hysteresis losses, thus significantly reducing iron losses. Furthermore, the addition of phosphorus can increase magnetic induction intensity, improve the material's machinability, and reduce cracks and defects during processing. Phosphorus, in synergy with other elements in steel, can also improve corrosion resistance and extend product service life.

[0014] The sulfur and nitrogen content should be reduced as much as possible (S≤0.001%, N≤0.002%) to prevent the formation of sulfide and nitride inclusions, which would reduce magnetic induction intensity and increase iron loss.

[0015] The molybdenum content is 0.05%–0.15%. Molybdenum can significantly improve the strength and toughness of steel. The addition of molybdenum can improve the hardenability of steel, allowing thick steel plates to achieve a more uniform property distribution during heat treatment. Furthermore, molybdenum can improve the thermal fatigue resistance of steel, enabling thick steel plates to better withstand thermal stress during the frequent start-stop cycles of intermittent drive motors. Molybdenum has a relatively small impact on electromagnetic properties.

[0016] A method for producing steel plates for intermittent drive motors includes the following process steps: converter smelting, continuous casting, hot rolling, normalizing, cold rolling, and finished product annealing. Specifically, it includes: (1) Continuous casting: During the continuous casting process, slag baffles are used, the slag baffle efficiency reaches more than 95%, the flow rate of cooling water in the crystallizer is controlled at 100-120 m³ / h, the fluctuation of liquid level in the crystallizer is controlled within ±2.0 mm, and the thickness of the billet is 160-220 mm. (2) Hot rolling: The heating furnace is heated at 1180℃~1280℃. The roughing is rolled in 3~5 passes. The total reduction rate in the roughing stage is 60%~70%. The reduction rate of the first two passes accounts for 40%~50% of the total reduction rate. The reduction rate of the subsequent passes gradually decreases. The final rolling temperature is 870℃~950℃. The thickness of the hot-rolled plate is 2.0mm~5.0mm. The cooling rate is controlled at 20℃~30℃ / s. The target value of the coiling temperature is 630℃~670℃. (3) Normalizing: The heating rate of the strip is controlled at 70-90℃ / min, the normalizing temperature is 900℃-1000℃, and the normalizing time is t=4.2h+1.7±2min, where h is the thickness of the hot-rolled plate in mm; the cooling method is high-speed laminar flow rapid air cooling, with laminar flow nozzles on the upper and lower surfaces blowing evenly at a wind speed of 25-30m / s, reducing the plate surface temperature from the temperature of the heat exchange to below 750℃ within 5s, and obtaining a fully recrystallized ferrite matrix after cooling is terminated, with an average grain size of 70-120μm; (4) Cold rolling: The total reduction rate of cold rolling is set at 40% to 50%, and the reduction rate is evenly distributed in each pass. The reduction rate of each pass is controlled at 10% to 15%. During the cold rolling process, the emulsion concentration is controlled at 2% to 4%, the temperature is controlled at 40℃ to 60℃, and the target thickness of cold rolling is 1.0 mm to 3.0 mm. (5) Finished product annealing: The heating rate of the strip is controlled at 50-90℃ / min, the heat soaking temperature is controlled at 750℃-850℃, the heat soaking time is 8min-15min, the protective atmosphere is pure hydrogen, and the cooling rate is controlled at 5℃ / s-15℃ / s.

[0017] The converter smelting process involves controlling the S and N contents to be below 0.001% and 0.002%, respectively. In the final stage of smelting, the argon gas is used for strong stirring with a flow rate of 250–350 L / min, a circulation flow rate of ≥180 t of molten steel / min, a vacuum degree of ≤67 Pa, and a stirring time of 3–7 minutes.

[0018] The hydrogen purity of the protective atmosphere described in step (5) is ≥99.999%, and the dew point is ≤−60℃; the hydrogen flow rate is set according to the strip width. Width ≤ 800mm, hydrogen flow rate 60±5Nm³ / h; 800mm < width ≤ 1200mm: Hydrogen flow rate 75±5Nm³ / h; 1200mm < width ≤ 1600mm: hydrogen flow rate 90±5Nm³ / h.

[0019] Compared with existing technologies, the beneficial effects of this invention are: 1. The composition is based on a quaternary synergy of Si-P-Mo-Mn: Si 0.50-1.50% increases resistivity and reduces eddy current loss, and together with 0.02%-0.06% P, it strengthens through solid solution and refines grains, while simultaneously reducing hysteresis loss without compromising toughness; 0.05%-0.15% Mo precipitates two-phase particles in air cooling, pinning dislocations and increasing yield strength. At the same time, Mo also reduces stacking fault energy and inhibits dislocation cross-slip, increasing the life of intermittent start-stop thermal cycles by 30%-40%, and can synergistically form a dense Mo-PO passivation film with P, improving the corrosion resistance of the steel plate; in addition, Mo segregates at γ-fiber grain boundaries, inhibiting abnormal growth of {111} oriented grains and improving magnetic induction; 0.5%-1.5% Mn expands the γ region and inhibits banded segregation, ensuring uniform properties in the thickness direction.

[0020] 2. In terms of process control, a thick billet-high energy-rapid cooling-precision control approach is adopted to achieve uniform microstructure and accurate performance: Thick billet: 160~220mm continuous casting billet, total compression ratio ≥43∶1, to ensure sufficient recrystallization, eliminate central segregation, and homogenize the diffusion of Mo and P.

[0021] High energy: High-temperature homogenization at 1180~1280℃, 60~70% hot rolling reduction, cumulative dislocation density ≥5×10 14 m -2 It provides the driving force for recrystallization; the final rolling temperature is 870-950℃ and the coiling temperature is 630-670℃, which controls the size and distribution of the precipitated phase.

[0022] Rapid cooling: During the normalization stage, laminar air cooling at 25-30 m / s is used to reduce the temperature to below 750°C within 5 seconds, locking in 70-120 μm ASTM 3-4 grade recrystallized ferrite to prevent grain coarsening; the normalization time ensures that the core and surface of different specifications are at the same temperature.

[0023] Precision control: Cold rolling and uniform pressing, pure hydrogen annealing, and full recrystallization after annealing weaken the γ-fiber texture, flatten the plate shape, and improve the surface quality, thereby achieving simultaneous improvement in strength and magnetic properties under thick specifications.

[0024] 3. This invention can meet both electromagnetic performance requirements and mechanical strength and processing performance, thereby improving the operating efficiency and reliability of intermittent drive motors and reducing production costs. Detailed Implementation

[0025] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. The reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0026] A steel plate for intermittent drive motor has the following chemical composition by mass fraction: C ≤ 0.003%, Si: 0.50%–1.50%, Mn: 0.5%–1.5%, P: 0.02%–0.06%, S ≤ 0.001%, N ≤ 0.002%, Mo: 0.05%–0.15%, Als: 0.20%–1.00%. The remainder is Fe and unavoidable residual elements.

[0027] A steel plate for an intermittent drive motor, the steel plate having a thickness of 1.0 mm to 3.0 mm.

[0028] A steel plate for intermittent drive motor, the mechanical properties of the steel plate are: yield strength Rp0.2 in the range of 280 to 420 MPa, and magnetic induction intensity ≥1.75T.

[0029] A method for producing steel plates for intermittent drive motors, specifically comprising: (1) Converter smelting: The converter smelting process adopts high-precision composition control technology to accurately regulate the content of the main alloying elements in the molten steel, ensuring their uniform distribution in the steel. During the smelting process, through multi-stage purification technology, the sulfur (S) and nitrogen (N) contents are strictly controlled to be below 0.001% and 0.002% respectively, in order to improve the toughness and fatigue resistance of the steel plate and meet the working conditions of frequent start-stop of the intermittent drive motor. In the final stage of smelting, strong stirring technology is adopted to increase the argon flow rate to 250-350 L / min, the circulation flow rate to ≥180 t molten steel / min, and the vacuum degree to ≤67 Pa, so that the molten steel circulation rate is increased by more than 15% compared with conventional smelting. The stirring time is dynamically adjusted to 3-7 minutes, which enhances the stability and reliability of the process while ensuring the uniformity and purity of the molten steel composition.

[0030] (2) Continuous casting: High-efficiency slag baffles are used during continuous casting, with a slag-blocking efficiency of over 95%, effectively blocking inclusion particles larger than 0.5 mm in diameter from entering the crystallizer, significantly reducing the inclusion content in the billet. At the same time, the cooling water flow rate of the crystallizer is controlled at 100-120 m³ / h to ensure uniform temperature on the inner wall of the crystallizer. The liquid level fluctuation in the crystallizer is controlled within ±2.0 mm, effectively reducing surface defects on the billet caused by liquid level fluctuations. The billet thickness is 160-220 mm, while ensuring a total compression ratio of ≥43:1, which meets the requirements for thick specifications and retains sufficient deformation energy for recrystallization and refinement. At the same time, due to the increase in billet thickness, the solidification time is correspondingly extended, promoting uniform diffusion of Mo and P, reducing banded structures, and improving the electromagnetic consistency in the thick section.

[0031] (3) Hot rolling: The heating furnace soaking temperature is controlled at 1180℃~1280℃. This temperature range ensures that the billet has good plasticity. The roughing rolling is carried out in 3-5 passes. The total reduction rate in the roughing rolling stage is 60%~70%, of which the reduction rate in the first two passes is larger, accounting for 40%~50% of the total reduction rate. The reduction rate gradually decreases in subsequent passes. This can effectively reduce the rolling force and ensure the stability of the rolling process. The final rolling temperature is 870℃~950℃ to ensure that the steel obtains good microstructure uniformity and mechanical properties. The thickness of the hot-rolled plate is 2.0~5.0mm. The cooling rate is controlled at 20℃ / s~30℃ / s. The target value range of the coiling temperature is 630℃~670℃. The purpose of the lower coiling temperature is to ensure that the coiled strip has good microstructure uniformity.

[0032] (4) Normalizing: The heating rate of the strip is controlled at 70-90℃ / min, and the normalizing temperature is 900℃-1000℃. Thick plates require a longer holding time to ensure temperature uniformity and microstructure uniformity throughout the thickness direction. The normalizing time is t=4.2h+1.7±2min, where h is the thickness of the hot-rolled plate in mm. The cooling method is high-speed laminar flow rapid air cooling: the laminar flow nozzles on the upper and lower surfaces are uniformly blown at a wind speed of 25-30m / s, and the plate surface temperature is rapidly reduced from the normalizing temperature to below 750℃ within 5s to inhibit grain growth. After the cooling is terminated, a fully recrystallized ferrite matrix is ​​obtained with an average grain size of 70-120μm (ASTM grade 3-4), straight grain boundaries and no banded segregation, which provides sufficient deformation energy for subsequent cold rolling and takes into account the strength of thick specifications and subsequent magnetic property optimization.

[0033] (5) Cold rolling: The total reduction rate of cold rolling is set at 40% to 50%, and the reduction rate of each pass is controlled at 10% to 15%. This can effectively avoid rolling defects caused by excessive reduction rate, while ensuring grain refinement. During cold rolling, the emulsion concentration is controlled at 2% to 4%, and the temperature is controlled at 40℃ to 60℃. Since the reduction rate of each pass is small, a lower concentration emulsion is used. This can avoid rolling slippage and emulsion residue while meeting various requirements. The target thickness of cold rolling is 1.0 mm to 3.0 mm.

[0034] (6) Finished product annealing: The heating rate of the strip is controlled at 50-90℃ / min to avoid internal stress caused by excessive heating rate. The soaking temperature should be controlled at 750℃-850℃. This temperature range can ensure that residual stress is fully released and avoid excessive grain growth, which will affect electromagnetic properties. The soaking time is adjusted according to the thickness of the steel plate, and the setting range is 8min-15min. Thicker steel plates require a longer annealing time to ensure performance uniformity. Pure hydrogen is used as the protective atmosphere. Pure hydrogen atmosphere has good reducing properties and can effectively prevent the steel plate from oxidizing during the annealing process. At the same time, it can also remove oxide scale and dirt on the surface of the steel plate and improve the surface quality of the product. When using pure hydrogen atmosphere, the purity and flow rate of hydrogen must be strictly controlled to ensure the safety and stability of the annealing process. Hydrogen purity ≥99.999%, dew point ≤−60℃; hydrogen flow rate is set according to the width of the strip: Width ≤ 800mm, hydrogen flow rate 60±5Nm³ / h; 800mm < width ≤ 1200mm: Hydrogen flow rate 75±5Nm³ / h; 1200mm < width ≤ 1600mm: hydrogen flow rate 90±5Nm³ / h.

[0035] The cooling rate should be controlled between 5℃ / s and 15℃ / s. A moderate cooling rate can avoid the increase of internal stress caused by excessive cooling, thereby ensuring the final performance of the steel plate.

[0036] To make the objectives, technical solutions, and technical effects of this invention clearer, the technical solutions in the embodiments of this invention are now described clearly and completely. However, the embodiments described below are only some embodiments of this invention, not all embodiments. All other embodiments obtained by those skilled in the art in conjunction with the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0037] The chemical composition of the examples is shown in Table 1; Table 1: Chemical Composition (%) Example 1: Method for producing steel plates for intermittent drive motors: a) Converter smelting Using RH vacuum refining technology and vacuum degassing, the sulfur (S) content reaches 0.0006% and the nitrogen (N) content reaches 0.0019%. High-power stirring technology is used, with a stirring time of 7 minutes to ensure uniform composition.

[0038] b) Continuous casting High-efficiency slag baffles are used in the continuous casting process, with a slag baffle efficiency of 96%. The flow rate of cooling water in the crystallizer is controlled at 120 m³ / h, and the fluctuation of the liquid level in the crystallizer is controlled within ±2.0 mm.

[0039] c) Hot-rolled The target range for slab homogenization temperature is 1200±20℃; the roughing rolling process consists of 4 passes, with a total reduction rate of 70% in the roughing stage, of which the reduction rate of the first two passes accounts for 50% of the total reduction rate; the target range for final rolling temperature is 890±20℃; the target value for hot-rolled plate thickness is 2.0mm; the cooling rate is 30℃ / s; and the target value for coiling temperature is 630℃.

[0040] d) Normalization The strip heating rate is controlled at 90℃ / min, and the normalizing and homogenization temperature is 900℃. The target homogenization time is 6 minutes. Temperature uniformity is ensured throughout the thickness of the strip. Rapid air cooling is used.

[0041] e) Cold rolling The process employs a four-pass cold rolling process: raw material thickness 2.0 mm, target thickness 1.0 mm, and total reduction rate 50%. The reduction rates for the four passes are 15%, 13%, 12%, and 10%, respectively. The target emulsion concentration is 4%, and the target temperature is 60℃.

[0042] f) Finished product annealing The heating rate of the strip entering the furnace is controlled at 90℃ / min, the target soaking temperature is 750℃, and the soaking time is 8min. Pure hydrogen is used as the protective atmosphere, and the cooling rate after annealing is 15℃ / s.

[0043] The performance of the 1.0mm specification product is shown in Table 2; Table 2: Example 2: Production method of steel plate for intermittent drive motor: a) Converter smelting Using RH vacuum refining technology and vacuum degassing, the sulfur (S) content reaches 0.0009% and the nitrogen (N) content reaches 0.0016%. High-power stirring technology is used, and the stirring time is 5 minutes to ensure uniform composition.

[0044] b) Continuous casting High-efficiency slag baffles are used in the continuous casting process, with a slag baffle efficiency of 96%. The flow rate of cooling water in the crystallizer is controlled at 110 m³ / h, and the fluctuation of the liquid level in the crystallizer is controlled within ±2.0 mm.

[0045] c) Hot-rolled The target range for slab homogenization temperature is 1220±20℃; the roughing process consists of 5 passes with a total reduction rate of 65%, of which the first two passes account for 45% of the total reduction rate; the target range for final rolling temperature is 910±20℃; the target value for hot-rolled plate thickness is 3.5mm; the cooling rate is 25℃ / s; and the target value for coiling temperature is 650℃.

[0046] d) Normalization The strip heating rate is controlled at 80℃ / min, and the normalizing and homogenization temperature is 950℃. The target homogenization time is 10 minutes. Temperature uniformity is ensured throughout the thickness of the strip. Rapid air cooling is employed.

[0047] e) Cold rolling The process employs a 4-pass cold rolling process: raw material thickness 3.5mm, target thickness 2.0mm, and total reduction rate 43%. The reduction rates for the 6 passes are 12%, 11%, 10%, and 10%, respectively. The target emulsion concentration is 3%, and the target temperature is 50℃.

[0048] f) Finished product annealing The heating rate of the strip entering the furnace is controlled at 70℃ / min, the target temperature for homogenization is 800℃, and the homogenization time is 11min. Pure hydrogen is used as the protective atmosphere, and the cooling rate after annealing is 10℃ / s.

[0049] The performance of the 2.0mm specification product is shown in Table 3; Table 3: Example 3: Production method of steel plate for intermittent drive motor: a) Converter smelting Using RH vacuum refining technology and vacuum degassing, the sulfur (S) content reaches 0.0007% and the nitrogen (N) content reaches 0.0014%. High-power stirring technology is used, with a stirring time of 3 minutes to ensure uniform composition.

[0050] b) Continuous casting High-efficiency slag baffles are used in the continuous casting process, with a slag baffle efficiency of 95%. The flow rate of cooling water in the crystallizer is controlled at 100 m³ / h, and the fluctuation of the liquid level in the crystallizer is controlled within ±2.0 mm.

[0051] c) Hot-rolled The target range for slab homogenization temperature is 1260±20℃; the roughing rolling process consists of 3 passes, with a total reduction rate of 60% in the roughing stage, of which the reduction rate of the first two passes accounts for 40% of the total reduction rate; the target range for final rolling temperature is 930±20℃; the target value for hot-rolled plate thickness is 5.0mm; the cooling rate is 20℃ / s; and the target value for coiling temperature is 670℃.

[0052] d) Normalization The strip heating rate is controlled at 70℃ / min, and the normalizing and homogenization temperature is 1000℃. The target homogenization time is 15min. Temperature uniformity is ensured throughout the thickness of the strip. Rapid air cooling is employed.

[0053] e) Cold rolling The process employs a four-pass cold rolling process: raw material thickness 5.0 mm, target thickness 3.0 mm, and total reduction rate 40%. The reduction rates for the four passes are 10%, 10%, 10%, and 10%, respectively. The target emulsion concentration is 2%, and the target temperature is 40℃.

[0054] f) Finished product annealing The heating rate of the strip entering the furnace is controlled at 50℃ / min, the target soaking temperature is 750℃, and the soaking time is 15min. Pure hydrogen is used as the protective atmosphere, and the cooling rate after annealing is 5℃ / s.

[0055] The performance of the 3.0mm specification product is shown in Table 4; Table 4: Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A steel plate for an intermittent drive motor, characterized in that, The chemical composition by mass fraction is as follows: C ≤ 0.003%, Si: 0.50%–1.50%, Mn: 0.5%–1.5%, P: 0.02%–0.06%, S ≤ 0.001%, N ≤ 0.002%, Mo: 0.05%–0.15%, Als: 0.20%–1.00%. The remainder is Fe and unavoidable residual elements.

2. The steel plate for an intermittent drive motor according to claim 1, characterized in that, The steel plate thickness is 1.0mm to 3.0mm.

3. The steel plate for an intermittent drive motor according to claim 1, characterized in that, Mechanical properties: Yield strength Rp0.2 is in the range of 280MPa to 420MPa, and magnetic induction intensity is ≥1.75T.

4. The method for producing a steel plate for an intermittent drive motor according to claim 1, characterized in that, The process steps include converter smelting, continuous casting, hot rolling, normalizing, cold rolling, and finished product annealing, specifically including: (1) Continuous casting: During the continuous casting process, slag baffles are used, the slag baffle efficiency reaches more than 95%, the flow rate of cooling water in the crystallizer is controlled at 100-120 m³ / h, the fluctuation of liquid level in the crystallizer is controlled within ±2.0 mm, and the thickness of the billet is 160-220 mm. (2) Hot rolling: The heating furnace is heated at 1180℃~1280℃. The roughing is rolled in 3~5 passes. The total reduction rate in the roughing stage is 60%~70%. The reduction rate of the first two passes accounts for 40%~50% of the total reduction rate. The reduction rate of the subsequent passes gradually decreases. The final rolling temperature is 870℃~950℃. The thickness of the hot-rolled plate is 2.0mm~5.0mm. The cooling rate is controlled at 20℃~30℃ / s. The target value of the coiling temperature is 630℃~670℃. (3) Normalizing: The heating rate of the strip is controlled at 70-90℃ / min, the normalizing temperature is 900℃-1000℃, and the normalizing time is t=4.2h+1.7±2min, where h is the thickness of the hot-rolled plate in mm; the cooling method is high-speed laminar flow rapid air cooling, with laminar flow nozzles on the upper and lower surfaces blowing evenly at a wind speed of 25-30m / s, reducing the plate surface temperature from the temperature of the heat exchange to below 750℃ within 5s, and obtaining a fully recrystallized ferrite matrix after cooling is terminated, with an average grain size of 70-120μm; (4) Cold rolling: The total reduction rate of cold rolling is set at 40% to 50%, and the reduction rate is evenly distributed in each pass. The reduction rate of each pass is controlled at 10% to 15%. During the cold rolling process, the emulsion concentration is controlled at 2% to 4%, the temperature is controlled at 40℃ to 60℃, and the target thickness of cold rolling is 1.0 mm to 3.0 mm. (5) Finished product annealing: The heating rate of the strip is controlled at 50-90℃ / min, the heat soaking temperature is controlled at 750℃-850℃, the heat soaking time is 8min-15min, the protective atmosphere is pure hydrogen, and the cooling rate is controlled at 5℃ / s-15℃ / s.

5. The method for producing a steel plate for an intermittent drive motor according to claim 4, characterized in that, The converter smelting process involves controlling the S and N contents to be below 0.001% and 0.002%, respectively. In the final stage of smelting, the argon gas is used for strong stirring with a flow rate of 250–350 L / min, a circulation flow rate of ≥180 t of molten steel / min, a vacuum degree of ≤67 Pa, and a stirring time of 3–7 minutes.

6. The method for producing a steel plate for an intermittent drive motor according to claim 4, characterized in that, In step (5), the hydrogen purity of the protective atmosphere is ≥99.999%, and the dew point is ≤−60℃; the hydrogen flow rate is set according to the strip width. Width ≤ 800mm, hydrogen flow rate 60±5Nm³ / h; 800mm < width ≤ 1200mm: hydrogen flow rate 75±5Nm³ / h; 1200mm < width ≤ 1600mm: hydrogen flow rate 90±5Nm³ / h.

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