CN117025917A - Method for preparing oriented silicon steel and oriented silicon steel - Google Patents

Method for preparing oriented silicon steel and oriented silicon steel Download PDF

Info

Publication number
CN117025917A
CN117025917A CN202310948255.XA CN202310948255A CN117025917A CN 117025917 A CN117025917 A CN 117025917A CN 202310948255 A CN202310948255 A CN 202310948255A CN 117025917 A CN117025917 A CN 117025917A
Authority
CN
China
Prior art keywords
bismuth
oriented silicon
silicon steel
steel
percent
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202310948255.XA
Other languages
Chinese (zh)
Inventor
项利
田飞
仇圣桃
汪净
李国仓
朱业超
谭清元
张丽琴
乔家龙
梁亮
罗钢
郑灵科
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hunan Lianyang Electromagnetic Materials Co ltd
Zhong Da National Engineering And Research Center Of Continuous Casting Technology Co ltd
Lysteel Co Ltd
Original Assignee
Hunan Lianyang Electromagnetic Materials Co ltd
Zhong Da National Engineering And Research Center Of Continuous Casting Technology Co ltd
Lysteel Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hunan Lianyang Electromagnetic Materials Co ltd, Zhong Da National Engineering And Research Center Of Continuous Casting Technology Co ltd, Lysteel Co Ltd filed Critical Hunan Lianyang Electromagnetic Materials Co ltd
Priority to CN202310948255.XA priority Critical patent/CN117025917A/en
Publication of CN117025917A publication Critical patent/CN117025917A/en
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/10—Supplying or treating molten metal
    • B22D11/108—Feeding additives, powders, or the like
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/001—Continuous casting of metals, i.e. casting in indefinite lengths of specific alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/002—Heat treatment of ferrous alloys containing Cr
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1216—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the working step(s) being of interest
    • C21D8/1222—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1216—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the working step(s) being of interest
    • C21D8/1233—Cold rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
    • C21D8/1244—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties the heat treatment(s) being of interest
    • C21D8/1272—Final recrystallisation annealing
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Electromagnetism (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacturing Of Steel Electrode Plates (AREA)

Abstract

The application discloses a method for preparing oriented silicon steel and the oriented silicon steel, the method comprises the following steps: continuously casting the molten steel through a crystallizer to obtain a casting blank, wherein a bismuth-containing simple substance or bismuth-containing alloy is added into the molten steel in the crystallizer; heating and hot rolling a casting blank to obtain a hot rolled plate, wherein the heating temperature is 1100-1250 ℃; and carrying out subsequent treatment on the hot rolled plate to obtain the oriented silicon steel. The oriented silicon steel has more uniform secondary grains and better magnetic performance.

Description

Method for preparing oriented silicon steel and oriented silicon steel
Technical Field
The application belongs to the technical field of steel product preparation, and particularly relates to a method for preparing oriented silicon steel and the oriented silicon steel.
Background
The oriented silicon steel is a secondary recrystallized steel product, is mainly used for iron cores of various transformers, and has extremely strict control on components and production process. In particular to oriented silicon steel with magnetic induction levels above 27QG100, 23QG100, 27QH095 and 23QH 090. The low-temperature slab heating is gradually becoming the mainstream production technology compared with the high-temperature slab heating.
The grain-oriented silicon steel inhibitor is a key for the production of the through-oriented silicon steel, and the selection of the grain-oriented silicon steel inhibitor is different due to the different slab temperatures. The common main inhibitors are AlN, mnS, cu 2 S, etc., auxiliary inhibitors include: bi. Sn, P, etc. At present, alN is generally used as a main inhibitor, and the inhibitor is reinforced by nitriding in the later working procedure, but the magnetic induction level of the oriented silicon steel is improved by the technology.
Disclosure of Invention
In view of the above, the application provides a method for preparing oriented silicon steel and oriented silicon steel, and aims to provide oriented silicon steel with high magnetic induction performance.
In a first aspect, an embodiment of the present application provides a method for preparing oriented silicon steel, including:
continuously casting the molten steel through a crystallizer to obtain a casting blank, wherein a bismuth-containing simple substance or bismuth-containing alloy is added into the molten steel in the crystallizer;
heating and rolling a casting blank to obtain a hot rolled plate, wherein the heating temperature is 1100-1250 ℃;
and carrying out subsequent treatment on the hot rolled plate to obtain the oriented silicon steel.
According to an embodiment of one aspect of the present application, the surface of molten steel in the mold contains mold flux, and the time of melting the bismuth-containing simple substance or bismuth-containing alloy at the interface of the molten steel and the mold flux is less than or equal to 0.5 seconds.
According to an embodiment of an aspect of the present application, the thickness of the mold flux is 3 to 20mm.
According to an embodiment of one aspect of the present application, the bismuth-containing simple substance or bismuth-containing alloy is strip-shaped in the length direction, and the cross section of the bismuth-containing simple substance or bismuth-containing alloy comprises a circular shape and a rectangular shape.
According to an embodiment of one aspect of the application, the bismuth-containing simple substance or bismuth-containing alloy is coated with a steel layer on the surface in the length direction, and the thickness of the steel layer is 0.2-1.0 mm.
According to an embodiment of an aspect of the present application, the temperature of the molten steel is 1530-1580 ℃.
According to an embodiment of one aspect of the present application, the chemical composition of the cast slab comprises, in mass percent: c:0.015% -0.2%, si:2.5 to 6.6 percent, mn:0.01 to 1.0 percent, P:
0.010％～0.06％；S:0.001％～0.03％，Als：0.010％～0.055％，N：
0.0050% -0.020%, bi:0.0001 to 0.01 percent, cu:0.01 to 0.40 percent of Sn:0.01 to 0.1 percent, cr:0.01 to 0.40 percent; the balance of Fe and other unavoidable impurity elements.
According to an embodiment of an aspect of the present application, the thickness of the cast slab is 40 to 300mm.
According to an embodiment of one aspect of the present application, the subsequent treatment is normalizing, cold rolling, decarburization nitriding and annealing, and the average size of crystal grains in the slab after the decarburization nitriding is 20 to 30 μm.
In a second aspect, an embodiment of the present application provides an oriented silicon steel, which is prepared by the method of the first aspect.
According to an embodiment of one aspect of the present application, the grain-oriented silicon steel has a magnetic induction level of > 1.90T and an average grain size of 5-40 mm.
Compared with the prior art, the application has at least the following beneficial effects:
according to the method provided by the application, the simple substance containing bismuth or the bismuth-containing alloy is added into the molten steel in the crystallizer, and the bismuth-containing simple substance or the bismuth-containing alloy is matched with the heated temperature, so that on one hand, the yield of bismuth in a casting blank of the oriented silicon steel can be improved, and on the other hand, the obtained oriented silicon steel has more uniform secondary grains and has more excellent magnetic performance (particularly higher magnetic induction).
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.
FIG. 1 shows a grain morphology diagram of an oriented silicon steel product of example 1 of the present application;
fig. 2 shows a grain morphology diagram of the oriented silicon steel product of comparative example 2 of the present application.
Detailed Description
In order to make the application object, technical scheme and beneficial technical effects of the application clearer, the application is further described in detail with reference to the following embodiments. It should be understood that the examples described in this specification are for the purpose of illustrating the application only and are not intended to limit the application.
For simplicity, only a few numerical ranges are explicitly disclosed. However, any lower limit may be combined with any upper limit to form a range not explicitly recited; and any lower limit may be combined with any other lower limit to form a range not explicitly recited, and any upper limit may be combined with any other upper limit to form a range not explicitly recited. Furthermore, each point or individual value between the endpoints of the range is included within the range, although not explicitly recited. Thus, each point or individual value may be combined as a lower or upper limit on itself with any other point or individual value or with other lower or upper limit to form a range that is not explicitly recited.
In the description of the present application, unless otherwise indicated, "above" and "below" are intended to include the present number, and the meaning of "multiple" in "one or more" means two or more.
The above summary of the present application is not intended to describe each disclosed embodiment or every implementation of the present application. The following description more particularly exemplifies illustrative embodiments. Guidance is provided throughout this application by a series of embodiments, which may be used in various combinations. In the various examples, the list is merely a representative group and should not be construed as exhaustive.
The oriented silicon steel is a steel product obtained through secondary recrystallization, is mainly used for iron cores of various transformers, has extremely strict control on components and production process, and particularly has excellent magnetic induction performance.
After molten steel is continuously cast to prepare a casting blank, researches show that the low-temperature heating of the casting blank has the advantages of low equipment requirement, energy conservation and less burning loss compared with the high-temperature heating of the casting blank. The grain-oriented silicon steel inhibitor is a key for the production of the through grain-oriented silicon steel, and the selection of the grain-oriented silicon steel inhibitor is different due to the different heating temperatures. The common main inhibitors are AlN, mnS, cu 2 S, etc., and also auxiliary inhibitors such as: sn, P, etc.
Bi, a low melting point metal, has a melting point of about 271 ℃, a boiling point of about 1560 ℃, and a saturation solubility in molten steel of about 20ppm. Bi is a high vapor pressure element, and is not easy to enter steel, and the vapor pressure in steel at 1450-1550 ℃ is higher than 1mmHg (0.133 kpa). Is similar to Sn, as, sb, etc., and is a grain boundary segregation element. By utilizing the characteristic, the addition of bismuth in certain alloy steels, particularly oriented silicon steel, can significantly improve certain characteristics.
Since the primary recrystallization and the secondary recrystallization processes will occur during the production of the oriented silicon steel. The addition of the inhibitor controls the second phase in the oriented silicon steel, and in a suppression system represented by AlN and MnS, the growth of primary recrystallization can be suppressed, and the development of secondary recrystallization can be promoted. In the production of Bi-containing high-magnetic-induction oriented silicon steel, bi is precipitated along the grain boundary of primary recrystallization, so that the movement of the grain boundary during primary recrystallization annealing is hindered, and the inhibition effect is achieved. In addition, when Bi coexists with a dispersion-precipitation inhibitor such as AlN and MnS, bi is easily vaporized at a high temperature, oxidation of AlN and MnS in an oxidizing atmosphere having a high dew point at a high temperature and coarsening of AlN due to nitriding in a reducing atmosphere having a relatively high nitrogen partial pressure can be prevented, and the size and the number of AlN and MnS can be kept stable, so that it can cooperate with a suppression system for AlN and MnS to greatly improve the magnetic properties of oriented silicon steel.
Bi has a low melting point and is easily gasified, so that Bi is difficult to be effectively added to molten steel during the smelting process of bismuth-containing alloy steel. According to the reaction sequence of bismuth in steel, bismuth element and oxidation reaction produce Bi 2 O 3 The combined oxygen in the steel is increased, and the bismuth is prevented from being taken away by deoxidizing elements, so that the generationBismuth element of (2) is dissolved in molten steel; the bismuth vapor is prevented from being generated when the molten steel is at high temperature, so that the bismuth vapor escapes from the molten steel. In order to improve the magnetic performance of the oriented silicon steel, the adding time of Bi can be further considered to ensure the yield. In the process of researching Bi-containing high-magnetic-induction oriented silicon steel, various methods for adding Bi into molten steel are developed.
In the related art, a lot of Bi elements are added into the oriented silicon steel, but after the Bi elements are added, thick slab continuous casting and high-temperature slab heating processes are usually adopted, so that low-temperature heating of casting blanks is difficult to realize.
In view of the above, the application provides a method for preparing oriented silicon steel, which can improve the magnetic property of oriented silicon steel and increase the yield of Bi.
Method for preparing oriented silicon steel
In a first aspect, an embodiment of the present application provides a method for preparing oriented silicon steel, including:
continuously casting the molten steel through a crystallizer to obtain a casting blank, wherein a bismuth-containing simple substance or bismuth-containing alloy is added into the molten steel in the crystallizer;
heating and rolling a casting blank to obtain a hot rolled plate, wherein the heating temperature is 1100-1250 ℃;
and carrying out subsequent treatment on the hot rolled plate to obtain the oriented silicon steel.
According to the method provided by the embodiment of the application, the bismuth-containing simple substance or bismuth-containing alloy is added into the molten steel in the crystallizer, and the casting blank is heated at a lower temperature, so that the yield of Bi element can be ensured, the pollution of Bi steam overflow to the environment can be reduced, the requirement of producing high-magnetic induction oriented silicon steel by a low-temperature plate blank process can be met, and the magnetic property of the oriented silicon steel can be improved. The method has simple process operation and is easy to realize and popularize.
In some embodiments, the heating temperature is 1150-1200 ℃, which can further improve the magnetic properties of the oriented silicon steel.
In some embodiments, the surface of molten steel in the crystallizer contains casting powder, and the time of the bismuth-containing simple substance or bismuth-containing alloy melting at the interface of the molten steel and the casting powder is less than or equal to 0.5 seconds.
According to the method provided by the embodiment of the application, the melting time of the bismuth-containing simple substance or bismuth-containing alloy is controlled, and the evaporation loss of bismuth can be avoided by controlling the partial pressure of bismuth on the surface of molten steel; the added bismuth-containing simple substance or bismuth-containing alloy acts together with an AlN and MnS inhibition system to inhibit primary crystallization of the oriented silicon steel and promote secondary recrystallization. Improving the comprehensive quality including magnetic performance and average grain size.
The reason for adding bismuth-containing simple substance or bismuth-containing alloy to molten steel in a crystallizer is as follows: the covering slag is arranged on the surface of the molten steel, so that the volatilization loss of bismuth in the molten steel in the whole process can be effectively reduced. The loss of bismuth in the molten steel is mainly carried out by diffusing and volatilizing the surface of the molten steel into air, the essential reason of the volatilization loss of bismuth on the surface of the molten steel is that the equilibrium steam partial pressure of bismuth on the surface of the molten steel is high at the temperature of the molten steel, the volatilization amount of bismuth is determined by the partial pressure of bismuth on the surface of the molten steel, and the lower the partial pressure of bismuth on the surface of the molten steel is, the more and the faster the volatilization loss of bismuth is; bismuth steam is rapidly oxidized when contacting with the atmosphere on the surface of molten steel in the smelting process, so that the partial pressure of bismuth is rapidly reduced, and volatilization of bismuth on the surface of molten steel is aggravated. In the continuous casting process, the surface of the molten steel is added with the protective slag, the temperature of the protective slag is lower than that of the molten steel, and the temperature of the top of the slag layer is relatively lower; the covering slag can prevent bismuth in molten steel from diffusing and volatilizing to the atmosphere, and is mainly because the temperature of the top surface of the slag layer is lower than that of the molten steel surface and the concentration of bismuth is also lower at the moment, so that the equilibrium partial pressure of bismuth can be effectively reduced, and the volatilization loss of bismuth is reduced.
In some embodiments, the elemental bismuth-containing or bismuth-containing alloy is continuously added to the molten steel at a rate that matches the rate of continuous casting of the molten steel. The simple substance containing bismuth or the bismuth alloy is controlled to be continuously added into molten steel, the adding speed is matched with the continuous casting speed of the molten steel, the casting blank added on the production line can have uniform bismuth content, and the stable quality of the casting blank in the same batch is comprehensively ensured.
In some embodiments, the thickness of the mold flux is 3 to 20mm, optionally 7 to 12mm. By controlling the thickness of the covering slag, the time from the bismuth-containing simple substance or bismuth-containing alloy entering the crystallizer to contact with molten steel can be controlled, the loss of bismuth can be effectively controlled, and the yield of bismuth is improved.
In some embodiments, the elemental bismuth-containing or bismuth-containing alloy is strip-shaped in length and comprises a circular or rectangular cross-section.
In some embodiments, the elemental bismuth-containing or bismuth-containing alloy is circular in cross-section with an outer diameter of 6-13 mm.
In some embodiments, the strip-shaped bismuth-containing simple substance or bismuth-containing alloy is inserted under the covering slag, which is favorable for further reducing the equilibrium partial pressure, thereby reducing the bismuth loss and improving the quality of the oriented silicon steel.
In some embodiments, the elemental bismuth-containing or bismuth-containing alloy is clad on the lengthwise surface with a steel layer having a thickness of 0.2 to 0.3mm. The surface-coated steel layer can prevent bismuth steam formed by bismuth-containing simple substances or bismuth-containing alloys from volatilizing before contacting molten steel, is beneficial to improving the yield of bismuth, and effectively controls the bismuth content in a casting blank, thereby improving the comprehensive performance of the oriented silicon steel.
In some embodiments, the temperature of the molten steel is 1530-1580 ℃. The temperature of the molten steel is in the range, which is favorable for smooth continuous casting process and can improve continuous casting quality. In addition, the molten steel at the temperature is beneficial to controlling the melting speed and melting time of the bismuth-containing simple substance or bismuth-containing alloy.
In some embodiments, the chemical composition of the cast strand comprises, in mass percent: c:0.015% -0.2%, si:2.5 to 6.6 percent, mn:0.01 to 1.0 percent, P:0.010 to 0.06 percent; s is 0.001-0.03%, als:0.010% -0.055%, N:0.0050% -0.020%, bi:0.0001 to 0.01 percent, cu:0.01 to 0.40 percent of Sn:0.01 to 0.1 percent, cr:0.01 to 0.40 percent; the balance of Fe and other unavoidable impurity elements. The molten steel can form an AlN and MnS system due to the cooperation of Al element, N element, mn element and S element with proper contents, thereby being beneficial to inhibiting the growth of grains of primary recrystallization of the oriented silicon steel and promoting secondary crystallization in the high-temperature annealing process of the oriented silicon steel. In addition, the magnetic property of the oriented silicon steel can be improved due to the fact that the oriented silicon steel contains the Bi element with proper content.
In some embodiments, the bismuth content in the bismuth-containing simple substance or bismuth-containing alloy is 90% or more, alternatively 95%, and further alternatively 98%.
According to the embodiment of the application, the casting blank has the appropriate content of Al element, N element, mn element and S element, and the elements are matched to form AlN and MnS, so that the primary recrystallized grain of the oriented silicon steel grows, the secondary crystallization is promoted in the high-temperature annealing process of the oriented silicon steel, and in addition, the magnetic property of the oriented silicon steel can be improved due to the appropriate content of Bi element.
In addition, the metallographic structure in the casting blank comprises equiaxed crystals and columnar crystals, and the average grain diameter of the grains in the structure is 1-10 mm, so that the magnetic performance of the casting blank is facilitated, and the structure defects are avoided.
In some embodiments, the thickness of the cast strand is 40 to 300mm. According to the embodiment of the application, the casting blank in the thickness range is favorable for heating at a lower temperature, so that primary recrystallization is conveniently inhibited by AlN and MnS systems and Bi elements together, and secondary recrystallization is promoted. Is favorable for avoiding the defect of abnormal secondary crystallization particles and finally improves the magnetic property
In some embodiments, the subsequent treatment includes normalizing, cold rolling, decarburization nitriding, and high temperature annealing, and the average size of the steel plate grains after the decarburization nitriding is 20 to 30 μm.
Oriented silicon steel
In a second aspect, an embodiment of the present application provides an oriented silicon steel, which is prepared by the method of the first aspect.
In some embodiments, the grain-oriented silicon steel has a magnetic induction level of > 1.90T and an average grain size of 5-40 mm. The oriented silicon steel has excellent magnetic induction performance and smaller grain size, and is beneficial to improving the comprehensive performance of the oriented silicon steel.
The magnetic induction level of the oriented silicon steel is more than 1.90T, and steel products with the grades more than 27QG100, 23QG100, 27QH095 and 23QH090 can be prepared.
Examples
The present disclosure is more particularly described in the following examples that are intended as illustrations only, since various modifications and changes within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the examples below are by weight, and all reagents used in the examples are commercially available or were obtained synthetically according to conventional methods and can be used directly without further treatment, as well as the instruments used in the examples.
Examples 1 to 5
Embodiments 1-5 provide a method for preparing oriented silicon steel comprising:
1) Molten steel is smelted in a converter, RH refined and continuously cast, and the casting blank comprises the following components in percentage by mass: c:0.015% -0.2%, si:2.5 to 6.6 percent, mn:0.01 to 1.0 percent, P:0.010 to 0.06 percent; s is 0.001-0.03%, als:0.010% -0.055%, N:0.0050% -0.020%, bi:0.0001 to 0.01 percent, cu:0.01 to 0.40 percent of Sn:0.01 to 0.1 percent, cr:0.01% -0.40%, and the balance of Fe and unavoidable impurity element components;
2) Transporting refined molten steel to a continuous casting platform, and transporting Bi wires to a position below mold flux by a wire feeder in the continuous casting process; the Bi line insertion depth is positioned under the protective slag; when the bismuth wire is fed, the temperature of molten steel in the crystallizer is 1530 ℃, and the thickness of the slag layer of the casting powder liquid is 7-12 mm. The Bi line melting time is less than 0.5 seconds; the outer skin of the bismuth wire is steel, the thickness of the steel plate is 0.2mm, and Bi powder with the purity more than or equal to 98% is adopted in the bismuth wire; the diameter of the bismuth wire is 8mm; the section is circular;
3) Adopting a low-temperature slab heating process, wherein the thickness of the slab is 220mm; the heating temperature of the plate blank is 1150-1200 ℃;
4) Performing hot rolling, normalizing, cold rolling, decarburization nitriding, mgO coating process, high-temperature annealing and the like to obtain the oriented silicon steel. The specific parameters of examples 1-5 are shown in tables 1 and 2.
Comparative examples 1 to 2
Comparative examples 1-2 differ from example 1 in that: the procedure and the timing of adding bismuth simple substance or bismuth alloy are different.
Comparative example 3
The difference from example 1 is that: the heating temperature of the cast blank was 1320 ℃.
Comparative example 4
The difference from example 1 is that: the heating temperature of the casting blank is 1320 ℃, and the subsequent working procedure has no nitriding.
Test part
The content of Bi in the oriented silicon steel in examples and comparative examples was examined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the results of the measurement of the yields thereof were calculated as shown in table 1.
And (5) observing and analyzing the primary recrystallized grains after decarburization and nitridation by adopting an optical microscope. The average sizes of the slab and the grain of the oriented silicon steel product were measured with a ruler, and the measured results are shown in table 2.
The magnetic induction performance of the oriented silicon steel is detected by using a GB/T3655 method, and the detected results are shown in Table 2.
TABLE 1
TABLE 2
As is clear from the results of Table 1, in the examples, the addition of the bismuth-containing simple substance or bismuth-containing alloy to the molten steel in the crystallizer can improve the magnetic induction and reduce the iron loss, while in the comparative examples 1-2, the addition of the bismuth-containing simple substance or bismuth-containing alloy in the other steps, the yield of the oriented silicon steel was lower, only 35.1% and 46.6%, and the slab heating temperature of comparative example 3 was 1320 ℃, making the magnetic properties of the oriented silicon steel inferior to those of Bi-containing examples 1 to 5 heated at low temperature. The slab of comparative example 3 was heated to 1320 c and had no nitriding step, and also had inferior magnetic properties to Bi-containing examples 1 to 5, which were heated at low temperatures.
FIG. 1 shows a surface topography of the oriented silicon steel of example 1, illustrating that the secondary recrystallization of the oriented silicon steel product is perfect and the grains are relatively uniform; fig. 2 shows the surface topography of the oriented silicon steel of comparative example 2, which illustrates that the secondary recrystallization of the oriented silicon steel product is more complete, but the fine grains are more, and the uniformity of the grains is lower than that of example 1.
While the application has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims (10)

1. A method for producing oriented silicon steel, comprising:
continuously casting the molten steel through a crystallizer to obtain a casting blank, wherein a bismuth-containing simple substance or bismuth-containing alloy is added into the molten steel in the crystallizer;
heating and hot rolling a casting blank to obtain a hot rolled plate, wherein the heating temperature is 1100-1250 ℃;
and carrying out subsequent treatment on the hot rolled plate to obtain the oriented silicon steel.
2. The method according to claim 1, wherein the surface of the molten steel in the mold contains mold flux, and the bismuth-containing simple substance or bismuth-containing alloy is melted at the interface of the molten steel and the mold flux for 0.5 seconds or less.
3. The method according to claim 2, wherein the thickness of the mold flux is 3 to 20mm.
4. A method according to any one of claims 1-3, characterized in that the elemental bismuth or bismuth-containing alloy is strip-shaped in the length direction, the cross section of which comprises a circular or rectangular shape.
5. The method according to claim 4, wherein the bismuth-containing simple substance or bismuth-containing alloy is coated with a steel layer on the surface in the length direction, and the thickness of the steel layer is 0.2-1 mm.
6. The method according to any one of claims 1 to 3, wherein the temperature of the molten steel is 1530 to 1580 ℃.
7. A method according to any one of claims 1 to 3, characterized in that the chemical composition of the cast strand comprises, in mass percent: c:0.015% -0.2%, si:2.5 to 6.6 percent, mn:0.01 to 1.0 percent, P:0.010 to 0.06 percent; s is 0.001-0.03%, als:0.010% -0.055%, N:0.0050% -0.020%, bi:0.0001 to 0.01 percent, cu:0.01 to 0.40 percent of Sn:0.01 to 0.1 percent, cr:0.01% -0.40% and the balance of Fe and other unavoidable impurity elements.
8. A method according to any one of claims 1 to 3, wherein the thickness of the cast strand is 40 to 300mm; and/or the number of the groups of groups,
the subsequent treatment is normalized, cold-rolled, decarburized and nitrided and annealed, and the average size of crystal grains in the slab after decarburized and nitrided is 20-30 mu m.
9. An oriented silicon steel prepared by the method of any one of claims 1 to 8.
10. The oriented silicon steel according to claim 9, wherein the oriented silicon steel has a magnetic induction level of > 1.90T and the average size of grains in the oriented silicon steel is 5-40 mm.
CN202310948255.XA 2023-07-31 2023-07-31 Method for preparing oriented silicon steel and oriented silicon steel Pending CN117025917A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310948255.XA CN117025917A (en) 2023-07-31 2023-07-31 Method for preparing oriented silicon steel and oriented silicon steel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310948255.XA CN117025917A (en) 2023-07-31 2023-07-31 Method for preparing oriented silicon steel and oriented silicon steel

Publications (1)

Publication Number Publication Date
CN117025917A true CN117025917A (en) 2023-11-10

Family

ID=88642187

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310948255.XA Pending CN117025917A (en) 2023-07-31 2023-07-31 Method for preparing oriented silicon steel and oriented silicon steel

Country Status (1)

Country Link
CN (1) CN117025917A (en)

Similar Documents

Publication Publication Date Title
RU2378394C1 (en) Manufacturing method of sheet of texturated electrical steel with high magnetic induction
US6309473B1 (en) Method of making grain-oriented magnetic steel sheet having low iron loss
US7377986B2 (en) Method for production of non-oriented electrical steel strip
KR101351149B1 (en) Method for producing grain-oriented electromagnetic steel plate
CN104884644A (en) Process for producing grain-oriented electromagnetic steel sheet
CN104870665A (en) Production method for grain-oriented electrical steel sheet and primary recrystallized steel sheet for production of grain-oriented electrical steel sheet
CN101311287B (en) Grain oriented magnetic steel sheet
JP5011711B2 (en) Manufacturing method of unidirectional electrical steel sheet
US20210130937A1 (en) Grain-oriented electrical steel sheet and manufacturing method therefor
CN104870666A (en) Production method for grain-oriented electrical steel sheet and primary recrystallized steel sheet for production of grain-oriented electrical steel sheet
JP2022514794A (en) Directional electrical steel sheet and its manufacturing method
CN108431267A (en) Oriented electrical steel and preparation method thereof
KR100722492B1 (en) Steel sheet for vitreous enameling and production method
JP4206665B2 (en) Method for producing grain-oriented electrical steel sheet having excellent magnetic properties and coating properties
CN117025917A (en) Method for preparing oriented silicon steel and oriented silicon steel
CN113195770B (en) Oriented electrical steel sheet and method for manufacturing the same
JPH07122090B2 (en) Method of melting directional silicon steel material
JP2000328207A (en) Silicon steel sheet excellent in nitriding and internal oxidation resistances
JPH05320769A (en) Production of silicon steel sheet excellent in magnetism and film property
CN114364821B (en) Grain-oriented electrical steel sheet and method for producing same
RU2799455C1 (en) Sheet from oriented electrical steel and method for its manufacturing
CN115449741B (en) High-magnetic induction oriented silicon steel produced based on sheet billet continuous casting and rolling and method
KR102319831B1 (en) Method of grain oriented electrical steel sheet
JPS6148761B2 (en)
JPH06220540A (en) High magnetic flux density grain-oriented silicon steel sheet excellent in magnetic property after domain control

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination