A production method of high-efficiency non-oriented silicon steel with good corrosion resistance

Abstract

The application discloses a production method of high-efficiency non-oriented silicon steel with good corrosion resistance, adopts a clean steel smelting method, smelts through narrow component control and continuously casts into a billet; the cast billet is preheated in heat preservation before hot rolling; the preheated cast billet is hot-rolled; the hot-rolled strip steel is normalized at 850±20 DEG C for 10-20 min; the finished product has a thickness of 0.35 mm; the finished product is annealed and coated; the chemical composition of the silicon steel is as follows: C: ≤0.0024%, Si: 0.26-1.42%, Al: ≤0.48%, Mn: 0.20-0.83%, P: ≤0.04%, S: ≤0.003%, Sb: 0.018-0.065%, Cu: 0.053-0.15%, and the rest is Fe and inevitable impurities. Through the chemical composition range and reasonable production process, the high-efficiency non-oriented silicon steel with high magnetic induction, low iron loss and good corrosion resistance is obtained.

Description

Technical Field

[0001] This invention relates to the field of sports equipment, and more particularly to a method for producing high-efficiency non-oriented silicon steel with good corrosion resistance. Background Technology

[0002] With the increasing stringent national requirements for green and environmentally friendly electrical products, effectively reducing the energy consumption of motor products is essential for achieving energy conservation and emission reduction. Meanwhile, non-oriented silicon steel inevitably comes into contact with corrosive media such as the atmosphere and rainwater during transportation, storage, and service. Due to its high Si content, a large number of oxygen atoms diffuse into the matrix of the non-oriented silicon steel, forming a large amount of Si and Fe oxides, leading to severe corrosion. In addition to oxygen, the atmosphere may contain impurities such as sulfur dioxide, hydrogen sulfide, and dust, accelerating silicon steel corrosion, reducing its utilization rate, and deteriorating its magnetic properties, further shortening the service life of equipment. Therefore, developing non-oriented silicon steel with lower iron loss, higher magnetic induction, and good corrosion resistance has become an important future development direction.

[0003] Currently, application number 202011372065.0 discloses a production method for high-efficiency non-oriented silicon steel sheets for motors with excellent corrosion resistance. It elaborates on the production processes, including chemical composition design, smelting, continuous casting, hot rolling, finish rolling, coiling, cold rolling, continuous annealing, and coating. It details the design of parameters such as key chemical elements, clean smelting, billet heating, final rolling temperature, coiling temperature, and annealing temperature, as well as their effects on magnetic properties and corrosion resistance. The production process is described in detail and comprehensively, and the theoretical explanation is thorough, which has a certain guiding role in the research and development of non-oriented silicon steel.

[0004] Application No. 202111240507.0 discloses a method for producing non-oriented silicon steel with good kerf corrosion resistance, detailing the entire process flow including chemical composition design, molten iron pretreatment, converter steelmaking, vacuum treatment, continuous casting, hot rolling, pickling, annealing, and insulating coating. This invention focuses on the optimal matching of reasonable component ratios with the production process to produce non-oriented silicon steel with low iron loss, high magnetic induction, and excellent kerf corrosion resistance.

[0005] Application No. 202310325599.5 discloses a method for producing ultra-thin corrosion-resistant silicon steel strip, describing the production processes including cold rolling on a four-roll mill, cleaning pretreatment, activation treatment, and preparation of an insulating coating. This invention details the effects of the preparation processes of the activation solution, the insulating impregnating adhesive, and the magnetothermal-electric coupling treatment process on improving the corrosion resistance and rust-inhibiting potential of non-oriented silicon steel. The content is comprehensive, providing a detailed and complete description of the production process of ultra-thin corrosion-resistant silicon steel strip. Summary of the Invention

[0006] The purpose of this invention is to provide a method for producing high-efficiency non-oriented silicon steel with good corrosion resistance. By determining the range of chemical composition and combining it with a reasonable production process, high-efficiency non-oriented silicon steel with high magnetic induction, low iron loss and good corrosion resistance can be obtained.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] This invention discloses a method for producing high-efficiency non-oriented silicon steel with good corrosion resistance, the production process and parameter control of which include:

[0009] A clean steel smelting method is adopted, and the steel is smelted and continuously cast into billets through narrow composition control;

[0010] Before hot rolling, the billet is preheated at a temperature of 1050-1200℃ and held at this temperature for 25-30 minutes to ensure uniform preheating.

[0011] The preheated billet is hot rolled, with the final rolling temperature controlled at 780-850℃ and the thickness of the hot-rolled strip controlled within the range of 1.8-2.3mm to ensure one-time cold rolling forming. After hot rolling, it is coiled at a higher temperature of 900±20℃. The coiling process promotes the recrystallization process, achieves uniform microstructure, thereby shortening the normalizing process and reducing production costs.

[0012] Hot-rolled strip steel is normalized at 850±20℃ for 10-20 minutes to achieve grain growth and uniform microstructure; then it is cold-rolled in one step through acid continuous rolling process to achieve a finished product thickness of 0.35mm.

[0013] The cold-rolled strip steel is annealed and coated in a N2+H2 protective atmosphere. The temperature of the heating section is controlled at 830-920℃ and the heating time is 52-90s. The temperature of the soaking section is controlled at 800-900℃ and the soaking time is 50-150s. The dew point temperature of the annealing section is controlled at ≤-30℃. The surface of the annealed steel strip is coated.

[0014] The chemical composition of the silicon steel by mass percentage is as follows: C: ≤0.0024%, Si: 0.26-1.42%, Al: ≤0.48%, Mn: 0.20-0.83%, P: ≤0.04%, S: ≤0.003%, Sb: 0.018-0.065%, Cu: 0.053-0.15%, with the remainder being Fe and unavoidable impurities.

[0015] Furthermore, the annealed steel strip surface is coated with 3.0-4.0 g / m 2 The coating ensures surface quality while also providing insulation.

[0016] Furthermore, the chemical composition of the silicon steel by mass percentage is as follows: C: 0.0022%, Si: 1.35%, Al: 0.35%, Mn: 0.25%, P: 0.015%, S: 0.0002%, Sb: 0.020%, Cu: 0.082%, with the remainder being Fe and unavoidable impurities.

[0017] Furthermore, the chemical composition of the silicon steel by mass percentage is as follows: C: 0.0018%, Si: 0.85%, Al: 0.27%, Mn: 0.56%, P: 0.022%, S: 0.0005%, Sb: 0.041%, Cu: 0.097%, with the remainder being Fe and unavoidable impurities.

[0018] Furthermore, the chemical composition of the silicon steel by mass percentage is as follows: C: 0.0015%, Si: 1.41%, Al: 0.45%, Mn: 0.82%, P: 0.018%, S: 0.0004%, Sb: 0.062%, Cu: 0.12%, with the remainder being Fe and unavoidable impurities.

[0019] Furthermore, the chemical composition of the silicon steel by mass percentage is as follows: C: 0.0020%, Si: 0.30%, Al: 0.32%, Mn: 0.61%, P: 0.011%, S: 0.0003%, Sb: 0.038%, Cu: 0.067%, with the remainder being Fe and unavoidable impurities.

[0020] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0021] This invention improves magnetic induction by adding the segregating element Sb, which reduces grain boundary energy through grain boundary segregation, suppresses the nucleation of undesirable texture {111}, and reduces the components of undesirable textures. Adding Cu activates the cathode effect, promoting anodic passivation and thus slowing corrosion. Simultaneously, an appropriate amount of Cu can form nanoscale Cu-rich precipitates, improving corrosion resistance while reducing iron loss; that is, adding Cu has a dual effect of reducing iron loss and improving corrosion resistance. Furthermore, this invention utilizes a high-temperature coiling process to promote the recrystallization degree and microstructure uniformity of the strip, thereby shortening the normalizing process time and effectively reducing production costs. Detailed Implementation

[0022] To better explain the present invention, the main contents of the present invention are further illustrated below with reference to specific embodiments.

[0023] Tables 1 and 2 show the chemical composition and performance test results of Examples 1-4 and Comparative Examples 1-3, respectively.

[0024] Table 1. Chemical composition (wt%) of various embodiments and comparative examples of the present invention.

[0025] Example C Si Mn P S Al Sb Cu 1 0.0022 1.35 0.25 0.015 0.0002 0.35 0.020 0.082 2 0.0018 0.85 0.56 0.022 0.0005 0.27 0.041 0.097 3 0.0015 1.41 0.82 0.018 0.0004 0.45 0.062 0.120 4 0.0020 0.30 0.61 0.011 0.0003 0.32 0.038 0.067 Comparative Example 1 0.0022 1.37 0.30 0.020 0.0006 0.36 0 0 Comparative Example 2 0.0018 1.32 0.37 0.018 0.0004 0.40 0.02 0 Comparative Example 3 0.0023 1.40 0.22 0.013 0.0005 0.38 0 0.120

[0026] Table 2 Performance test results of embodiments and comparative examples of the present invention

[0027]

[0028]

[0029] As shown in Tables 1 and 2, by adding appropriate amounts of Sb and Cu and controlling the optimized process and parameters, the magnetic induction intensity B50 of this invention can reach 1.73T, the iron loss can be reduced to 2.65W / kg, and the 6h salt corrosion area can be reduced to 2.0%. That is, by adding appropriate amounts of alloying elements, the magnetic induction of non-oriented silicon steel can be effectively improved, the iron loss can be reduced, and the corrosion resistance can be effectively improved, thereby improving the overall performance of non-oriented silicon steel.

[0030] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for producing high-efficiency non-oriented silicon steel with good corrosion resistance, characterized in that: Its production process and parameter control include: A clean steel smelting method is adopted, and the steel is smelted and continuously cast into billets through narrow composition control; Before hot rolling, the billet is preheated at a temperature of 1050-1200℃ and held at this temperature for 25-30 minutes to ensure uniform preheating. The preheated billet is hot rolled, with the final rolling temperature controlled at 780-850℃ and the thickness of the hot-rolled strip controlled within the range of 1.8-2.3mm to ensure one-time cold rolling forming. After hot rolling, it is coiled at a higher temperature of 900±20℃. The coiling process promotes the recrystallization process, achieves uniform microstructure, thereby shortening the normalizing process and reducing production costs. Hot-rolled strip steel is normalized at 850±20 ℃ for 10-20 min to achieve grain growth and uniform microstructure; then it is cold-rolled in one step by acid continuous rolling process to form a finished product with a thickness of 0.35 mm. The cold-rolled strip steel is annealed and coated in a N2+H2 protective atmosphere. The temperature of the heating section is controlled at 830-920℃ and the heating time is 52-90s. The temperature of the soaking section is controlled at 800-900℃ and the soaking time is 50-150s. The dew point temperature of the annealing section is controlled at ≤-30℃. The surface of the annealed steel strip is coated. The chemical composition of the silicon steel by mass percentage is as follows: C: 0.0015%, Si: 1.41%, Al: 0.45%, Mn: 0.82%, P: 0.018%, S: 0.0004%, Sb: 0.062%, Cu: 0.12%, with the remainder being Fe and unavoidable impurities.

2. The method for producing high-efficiency non-oriented silicon steel with good corrosion resistance according to claim 1, characterized in that: The annealed steel strip surface is coated with 3.0-4.0 g / m 2 The coating ensures surface quality while also providing insulation.

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