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CN-121732553-B - Full-process production method of ultrathin high-grade non-oriented silicon steel and acid continuous rolling synergistic twenty-roller finish cold rolling thereof

CN121732553BCN 121732553 BCN121732553 BCN 121732553BCN-121732553-B

Abstract

The application discloses a full-flow production method of ultra-thin high-grade non-oriented silicon steel and acid continuous rolling synergistic twenty-roller finish cold rolling. The thickness of the non-oriented silicon steel is (0.05-0.15) +/-0.002 mm. The production method comprises the steps of heating, soaking at 1000-1140 ℃, hot rolling, namely, initial rolling at a temperature of more than or equal to 950 ℃ for first pass finish rolling, final rolling at a temperature of 850+/-15 ℃ for last pass finish rolling, hot rolling at a plate thickness of 1.80-2.30 mm, coiling at a temperature of 630+/-15 ℃, acid continuous rolling, namely, pickling and continuous cold rolling for multiple passes by adopting a multi-frame acid continuous rolling unit, wherein the thickness of a hard plate is 0.2-0.35 mm, normalizing the hard plate in a normalizing furnace to obtain a normalized hard plate, normalizing at a temperature of 850-950 ℃, twenty-roller finish cold rolling, annealing at an annealing temperature of 900-1000 ℃ and annealing time of 40-120 s.

Inventors

  • YUE ZHONGXIANG
  • LUO RUI
  • WU SHENGJIE
  • CHENG XIAONONG
  • HU XIANJUN
  • MA HAN

Assignees

  • 江苏沙钢钢铁有限公司
  • 江苏大学
  • 张家港扬子江冷轧板有限公司
  • 江苏省沙钢钢铁研究院有限公司
  • 江苏沙钢集团有限公司

Dates

Publication Date
20260505
Application Date
20260226

Claims (16)

  1. 1. A production method of ultrathin high-grade unoriented silicon steel is characterized by comprising the following steps of, Heating the continuous casting blank in a heating furnace, wherein the soaking temperature is 1000-1140 ℃; The hot rolling process comprises the steps of carrying out multi-pass rough rolling and multi-pass finish rolling on a continuous casting blank, wherein the thickness of an intermediate blank obtained by rough rolling is 30-40 mm, the initial rolling temperature of the first-pass finish rolling is more than or equal to 950 ℃, the final rolling temperature of the last-pass finish rolling is 850+/-15 ℃, and the thickness of a hot rolled plate obtained by finish rolling is 1.80-2.30 mm; coiling the hot rolled plate to obtain a hot rolled coil, wherein the coiling temperature is 630+/-15 ℃; an acid continuous rolling procedure, namely, opening the hot rolled coiled sheet, and then adopting a multi-rack acid continuous rolling unit to carry out acid washing and multi-pass continuous cold rolling to obtain a hard rolled sheet with the thickness of 0.2-0.35 mm; Normalizing the hard rolled plate in a normalizing furnace to obtain a normalized hard rolled plate, wherein the normalizing temperature is 850-950 ℃, the normalizing time is 60-100 s, the tension in the normalizing furnace is 8-10N/mm 2 , the temperature is controlled and cooled after the normalizing time is reached, the cooling speed is 10-15 ℃ per second when the surface temperature of the steel plate is more than or equal to 400 ℃, and the cooling speed is 15-20 ℃ per second when the surface temperature of the steel plate is less than 400 ℃; A twenty-roller finish cold rolling step, namely adopting a twenty-roller single-frame cold rolling mill to perform finish cold rolling on the normalized rolling hard plate to obtain a finish cold-rolled plate with the thickness h of (0.05-0.15) +/-0.002 mm; And annealing the refined cold-rolled sheet in an annealing furnace, wherein the annealing temperature is T+/-10 ℃, the unit of T is the temperature, the value of T is expressed in a formula 820+200 (11 Si-14Mn+21Al) +400h mm -1 , the element symbols in the formula represent the mass percentage of corresponding elements in the continuous casting blank, the annealing time is 40-120 s, and then the sheet is cooled to obtain a non-oriented silicon steel finished product.
  2. 2. The method for producing the ultrathin high-grade unoriented silicon steel according to claim 1, characterized in that the annealing process comprises the step of controlling the tension in an annealing furnace to be 1-3N/mm 2 .
  3. 3. The method for producing the ultrathin high-grade unoriented silicon steel according to claim 1, wherein the annealing process is performed for a length of annealing (30-50) s+400h s/mm, and h is the thickness of the fine cold-rolled sheet and has a unit of mm.
  4. 4. The production method of the ultrathin high-grade unoriented silicon steel according to claim 1, characterized in that the twenty-high-grade unoriented silicon steel is subjected to 2-4-pass finish cold rolling, the total reduction rate is 40-80%, and the reduction rate of the first-pass finish cold rolling is more than or equal to 30%.
  5. 5. The production method of the ultrathin high-grade unoriented silicon steel according to claim 1 is characterized in that the acid continuous rolling procedure comprises the steps of reducing the reduction rate of the first-pass cold rolling by 20-30% and the reduction rate of the first-pass cold rolling by less than or equal to 0.60mm, and controlling the bending force of each rack working roll of the acid continuous rolling to be 50-150 kN, so that the edge of the obtained rolled hard plate generates controllable edge waves with the height of 1.0-2.5 mm.
  6. 6. The method for producing ultra-thin high grade non-oriented silicon steel according to claim 1, wherein the hot rolling step is a step of rolling with a total rolling reduction of 93-95% and a rolling reduction of 20-25% in the final pass.
  7. 7. The method for producing ultra-thin high grade non-oriented silicon steel according to claim 1, wherein the acid continuous rolling step is to directly perform multi-pass continuous cold rolling without preheating after pickling; And the twenty-roller finish cold rolling process is free from preheating before finish cold rolling.
  8. 8. The method for producing the ultrathin high-grade unoriented silicon steel according to claim 1, wherein the annealing step is performed by performing temperature-controlled cooling after the annealing time is reached, wherein the cooling rate is 5-10 ℃ per second when the surface temperature of the steel plate is more than 700 ℃, the cooling rate is 10-15 ℃ per second when the surface temperature of the steel plate is 400-700 ℃, and the cooling rate is 15-20 ℃ per second when the surface temperature of the steel plate is less than 400 ℃.
  9. 9. The method for producing the ultrathin high-grade unoriented silicon steel according to claim 1, wherein the twenty-roller finish cold rolling process is characterized in that the working roller diameter of the twenty-roller single-stand cold rolling mill is 45-65 mm, the roughness of the working roller for the first-pass finish cold rolling is 2.50+/-0.50 mu m, and the roughness of the working roller for the last-pass finish cold rolling is 0.50+/-0.10 mu m.
  10. 10. The method for producing the ultrathin high-grade unoriented silicon steel according to claim 1, wherein the acid continuous rolling process is characterized in that the multi-frame acid continuous rolling unit is any one of a six-roller five-frame acid continuous rolling unit, a six-roller six-frame acid continuous rolling unit or an eighteen-roller six-frame acid continuous rolling unit.
  11. 11. The method for producing the ultrathin high-grade unoriented silicon steel according to claim 1, characterized by comprising the heating step of preserving the heat of a continuous casting blank at a soaking temperature for 40-60 min.
  12. 12. The method for producing ultrathin high-grade unoriented silicon steel according to claim 1, characterized in that the thickness of the continuous casting billet is 200-250 mm; the chemical components of the continuous casting blank comprise, by mass, less than or equal to 0.005% of C, 3.2-3.7% of Si, 0.3-0.8% of Mn, 0.70-1.2% of Al, less than or equal to 0.01% of S, less than or equal to 0.08% of P, less than or equal to 0.01% of N, less than or equal to 0.01% of O, less than or equal to 5.0% of Cr, ni and Cu respectively, less than or equal to 0.1% of Mo, nb, V, ti% of Fe and unavoidable impurities.
  13. 13. The method for producing ultra-thin high grade non-oriented silicon steel according to claim 12, wherein the chemical composition of the continuous casting billet in mass percent satisfies any one or more of the following ：C≤0.0025%,S≤0.0015%,P≤0.03%,N≤0.003%,O≤0.003%,Nb≤0.004%,V≤0.004%,Ti≤0.005%,Mo≤0.004%,Cr≤0.03%,Ni≤0.03%,Cu≤0.03%,Nb+V+Ti+Mo≤0.009%,Cr+Ni+Cu≤0.06%.
  14. 14. The ultrathin high-grade non-oriented silicon steel is characterized by comprising, by mass, less than or equal to 0.005% of C, 3.2-3.7% of Si, 0.3-0.8% of Mn, 0.70-1.2% of Al, less than or equal to 0.01% of S, less than or equal to 0.08% of P, less than or equal to 0.01% of N, less than or equal to 0.01% of O, less than or equal to 5.0% of Cr, less than or equal to 0.1% of Ni and Cu respectively, and Fe and unavoidable impurities, wherein the ultrathin high-grade non-oriented silicon steel is prepared by the production method of the ultrathin high-grade non-oriented silicon steel according to any one of claims 1-13; The grain size of the recrystallization of the non-oriented silicon steel is 500-1000 hours mu m/mm; the iron loss P 1.0/400 of the non-oriented silicon steel is less than or equal to 9.5W/kg, the iron loss P 0.5/1000 is less than or equal to 15.0W/kg, and the magnetic induction intensity B 5000 is more than or equal to 1.63T.
  15. 15. The ultra-thin high grade non-oriented silicon steel as claimed in claim 14, wherein the thickness of the non-oriented silicon steel is 0.05+ -0.002 mm, the iron loss P 1.0/400 is less than or equal to 8.0W/kg, the iron loss P 0.5/1000 is less than or equal to 12.0W/kg, and the magnetic induction intensity B 5000 is more than or equal to 1.63T; Or the thickness of the non-oriented silicon steel is 0.08+/-0.002 mm, the iron loss P 1.0/400 is less than or equal to 8.5W/kg, the iron loss P 0.5/1000 is less than or equal to 13.0W/kg, and the magnetic induction intensity B 5000 is more than or equal to 1.63T; Or the thickness of the non-oriented silicon steel is 0.10+/-0.002 mm, the iron loss P 1.0/400 is less than or equal to 9.0W/kg, the iron loss P 0.5/1000 is less than or equal to 14.0W/kg, and the magnetic induction intensity B 5000 is more than or equal to 1.63T; Or the thickness of the non-oriented silicon steel is 0.15+/-0.002 mm, the iron loss P 1.0/400 is less than or equal to 9.5W/kg, the iron loss P 0.5/1000 is less than or equal to 15.0W/kg, and the magnetic induction intensity B 5000 is more than or equal to 1.63T.
  16. 16. The ultra-thin high grade non-oriented silicon steel as claimed in claim 14, wherein the chemical composition of the non-oriented silicon steel comprises any one or two of 0.01-0.15% of Sn and 0.01-0.15% of Sb by mass percent.

Description

Full-process production method of ultrathin high-grade non-oriented silicon steel and acid continuous rolling synergistic twenty-roller finish cold rolling thereof Technical Field The application belongs to the technical field of steel material preparation, relates to ultra-thin high-grade non-oriented silicon steel and a production method of the ultra-thin high-grade non-oriented silicon steel, and in particular relates to a full-flow production method of acid continuous rolling and twenty-roller finish cold rolling of the ultra-thin high-grade non-oriented silicon steel. Background With acceleration of global electrification progress and vigorous development of new energy industry, demands for high efficiency, energy saving, high rotation speed, high power density and light weight of electric devices are increasing. In order to meet the requirements of high efficiency, high rotation speed, high power density and light weight, the non-oriented silicon steel is required to have the characteristics of medium and high frequency, low loss, high magnetic induction, ultra-thin and the like. The non-oriented silicon steel with the thickness of 0.15mm or less belongs to ultra-thin non-oriented silicon steel and is mainly applied to medium-high frequency working conditions of 400Hz or more. As an excellent soft magnetic material, the ultrathin non-oriented silicon steel is mainly used as an iron core material in the fields of power electronics, military industry, new energy automobiles, low-altitude economy and the like. The current preparation method of the ultrathin non-oriented silicon steel mainly comprises the following three steps. First, a twin roll continuous casting process. For example, in the Chinese patent application with the application number 201810441471.4, molten steel obtained by smelting is cast-rolled into a thin strip with the thickness of 1.0-4.0 mm by a double-roll thin strip continuous casting machine, hot rolling is carried out when the temperature of the thin strip is reduced to 800-1200 ℃ to obtain a hot rolled thin strip, and then three times of cold rolling and three times of annealing are carried out to obtain the non-oriented silicon steel ultrathin strip with the thickness of 0.05-0.20 mm. In the method, the casting and rolling speed is far lower than the speed of conventional continuous casting and hot rolling, and three cold rolling and three annealing are needed, so that the overall production efficiency is very low and the production cost is very high. Second, planar casting. For example, the Chinese patent application with the application number 202310981198.5 takes pure iron and high-purity silicon as raw materials, and is cast into a master alloy cast ingot after being melted, the master alloy cast ingot is placed in a heating device with a nozzle at the bottom for heating and melting, and then the melt is sprayed onto a copper roller rotating at a high speed through the nozzle, and the non-oriented silicon steel ultrathin strip with the thickness of 0.03-0.16 mm is formed after natural solidification. The method can only produce the strip steel with the width of 1-15 mm, has extremely low production efficiency and extremely high production cost, cannot produce wide-specification products, and hardly meets the actual industrial requirements. Third, the traditional continuous casting-hot rolling-normalizing-multiple cold rolling-multiple annealing method. For example, the Chinese patent application with the application number of 202410879950.X is subjected to continuous casting, hot rolling, normalizing, pickling, cold rolling, annealing, secondary cold rolling and secondary annealing to obtain the ultrathin non-oriented silicon steel with the thickness of (0.10-0.15) +/-0.005 mm. In the method, the normalizing of the hot rolled plate is a necessary procedure for ensuring magnetic performance, but the normalizing of the hot rolled plate can greatly increase the difficulty of subsequent cold rolling, so that the hot rolled plate needs to be preheated before secondary cold rolling, for example, 80-120 ℃ is needed in China patent application of 202410879950.X, otherwise, edge cracking and even belt breakage can occur in cold rolling, the preheating before cold rolling can lead to long flow and high cost, and in order to reduce the risk of cold rolling belt breakage, the hot rolled plate also needs auxiliary technologies such as low thickness, high cold rolling first pass high pressure and the like, but the problems of high production difficulty of hot rolling, high production difficulty of cold rolling, high equipment requirement, low production efficiency and the like can be caused. Disclosure of Invention In order to solve the technical problems, the application aims to provide the ultrathin high-grade non-oriented silicon steel and a production method of the ultrathin high-grade non-oriented silicon steel, in particular to a full-flow production method of acid continuous rollin