Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C33/00—Making ferrous 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
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
  • C21D8/0278—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips involving a particular surface treatment
  • C21D8/0284—Application of a separating or insulating coating
• • 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
  • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
  • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
  • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
  • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following 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
• • 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
  • C21D8/1255—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 with diffusion of elements, e.g. decarburising, nitriding
• • 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
  • C21D8/1261—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 following 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
  • C21D8/1244—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
  • 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
  • C21D8/1277—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties involving a particular surface treatment
  • C21D8/1283—Application of a separating or insulating coating
• • 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
  • C22C38/008—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
  • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
• • 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
  • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
  • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
  • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
  • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
  • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
  • H01F1/16—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of sheets

Definitions

• the present invention relates to a method of producing oriented silicon steel, and more particularly to a method of producing a high magnetic flux density oriented silicon steel product. Background technique
• the production method of the traditional high magnetic flux density oriented silicon steel is as follows: steelmaking by converter (or electric furnace), secondary refining and alloying, continuous casting into slab, the basic chemical composition is: s so / C 0.06 ⁇ 0.10%, Mn 0.03 to 0.1%, S 0.012 to 0.050%, Als 0.02 to 0.05%, N 0.003 to 0.012%, and some component systems further contain one or more of elements such as Cu, Mo, Sb, B, and Bi, and the rest. It is an element of iron and inevitable impurities.
• the slab is heated to a temperature above 1350 °C in a special high-temperature heating furnace, and is kept for more than 45 minutes, so that the favorable inclusions MnS or A1N are fully dissolved, and then rolled, and the finishing temperature reaches 950 ° C or higher.
• pickling is performed to remove the surface iron oxide scale; cold rolling is performed to roll the sample to the finished product thickness.
• the [C] in the steel sheet is removed to the extent that it does not affect the magnetic properties of the finished product (generally should be less than 30 ppm); during the high temperature annealing, the steel sheet occurs twice. Recrystallization, formation and purification of magnesium silicate underlayer (removing elements such as S and N in steel which are harmful to magnetic properties), etc., obtaining high magnetic induction oriented silicon steel with high degree of orientation and low iron loss; Insulating coatings and stretch annealing provide oriented silicon steel products in commercial applications.
• the heating temperature is up to 1400 ° C, which is the limit level of the conventional furnace.
• the heating temperature is high, the burning is large, the heating furnace needs frequent repair, and the utilization rate is low.
• high energy consumption and large edge cracking of the hot rolled coil make the cold rolling process difficult to produce, the finished product rate is low, the magnetic properties of the finished product are not ideal, and the cost is high.
• the slab heating temperature is between 1250 and 1320 °. C, using A1N and Cu inhibitors; the other is the slab heating temperature of 1100 ⁇ 1250 ° C, mainly using decarburization after nitriding formation inhibitors to obtain inhibition ability.
• the low temperature slab heating technology has developed rapidly.
• US Patent No. 5,049,205 and Japanese Patent Laid-Open No. 5-112827 use slab heating below 1200 °C for final cold rolling.
• Chinese patent CN 200510110899 describes a new process for slab heating below 1200 ° C, and decarburization annealing of the cold rolled sheet that has been rolled to the finished thickness, but requires strict control of the dew point during the nitriding process. At the same time, new problems of difficulty in decarbonization will be introduced.
• Korean patent KR 2002074312 proposes a method of decarburization and nitriding with slab heating after slab heating below 1200 °C. Although this can solve the problem of post-decarburization difficulty or post-nitriding difficulty, it is still unavoidable. Uneven nitriding causes problems such as uneven magnetic properties and high cost of the product.
• Nb element is added to steelmaking.
• 0.02 to 0.20% of Nb is added to the steelmaking component for the purpose of recrystallizing the hot rolled sheet by forming precipitates such as tantalum carbide and tantalum nitride.
• the microstructure is refined to improve the grain distribution and aggregate structure of the decarburization annealed sheet, and acts as an auxiliary inhibitor in the high temperature annealing process to suppress the growth of normal grains, thereby improving the magnetic properties of the oriented silicon steel.
• the problem with this patent is that in order to obtain precipitates such as tantalum nitride before hot rolling, high temperature slab heating technology must be employed, which inevitably leads to problems such as large burning loss, high energy consumption, low yield, and high cost.
• Nitride added to the MgO release agent as proposed in Japanese Patent No. 51106622 and U.S. Patent No. 417,1994, the addition of nitrates of Al, Fe, Mg and Zn to the MgO release agent, which are decomposed during high temperature annealing and infiltrated into the plate. nitrogen.
• the products of decomposition of these nitrides are nitrogen oxides, oxygen, and the like, there is a danger of explosion in actual production.
• Japanese patents JP61096080 and JP62004881 respectively propose to add Mn and Si Nitride to meet nitriding during high temperature annealing.
• this method has a problem in that since the above-mentioned nitride has high thermal stability, its decomposition efficiency is low, and it is necessary to lengthen the annealing time or increase the amount of nitride to satisfy the nitriding requirement.
• the control of the temperature rise rate of the high-temperature annealing can be achieved by lowering the temperature increase rate in the high-temperature annealing process to obtain the high-flux density oriented silicon steel.
• simply lowering the rate of temperature rise will result in a significant drop in production efficiency.
• the object of the present invention is to provide a method for producing a high magnetic flux density oriented silicon steel product, which solves the problem of nitriding difficulty in producing high magnetic induction oriented silicon steel by low temperature slab heating technology, and at the same time adopts low temperature heating technology to effectively ensure a series of equipment such as a steelmaking furnace. It is safe, stable and has a long service life. Since the steel sheet is nitrided during the high-temperature annealing process, it can ensure the secondary recrystallization is perfect, and finally obtain a high magnetic flux density oriented silicon steel product with excellent magnetic properties.
• the steel sheet is more susceptible to nitrogen absorption during the high temperature annealing process because the nitrogen content determines whether the magnetic properties of the final finished sheet are up to standard.
• a nitrogen-containing compound to the MgO release agent, it is applied to the surface of the steel sheet, and is thermally decomposed during the high-temperature annealing process, thereby achieving a uniform purpose of nitriding into the steel sheet.
• the nitrogen content before the second temperature rise, and the secondary temperature rise temperature different heating rates are adjusted to ensure the secondary recrystallization is perfect, and finally a high magnetic flux density excellent in magnetic properties is obtained.
• Oriented silicon steel products according to the Nb content in the steel, the nitrogen content before the second temperature rise, and the secondary temperature rise temperature, different heating rates are adjusted to ensure the secondary recrystallization is perfect, and finally a high magnetic flux density excellent in magnetic properties is obtained.
• a method for producing a high magnetic flux density oriented silicon steel product of the present invention includes the following steps:
• the weight percentage of the oriented silicon steel composition is: C 0.035-0.065%, Si 2.9-4.0%, Mn 0.05-0.20%, S 0.005-0.012%, Als 0.015-0.035%, N 0.004-0.009%,
• the slab is heated in the heating furnace to 1090 ⁇ 1200 °C, rolling below 1180 °C, finishing at 860 °C or more, laminar cooling after rolling, and coiling below 650 °C; Normalization process: normalizing temperature is 1050 ⁇ 1180. C, time l ⁇ 20sec, normalization temperature 850-950 V, time 30 ⁇ 200sec; then cooling, cooling rate 10 ⁇ 60 °C/sec;
• the steel plate After normalization, the steel plate is rolled to the thickness of the finished plate, and the cold rolling reduction rate is ⁇ 75% ;
• the surface of the steel plate is coated with MgO as the main component, 0.1 ⁇ 10% NH 4 C1 and 0.5 ⁇ 30% P 3 N 5 , and the balance is MgO, in weight percentage;
• An insulating coating is applied on the surface of the high temperature annealed sheet, and a high magnetic flux density oriented silicon steel excellent in magnetic properties is obtained by hot drawing flat annealing.
• the present invention adds an appropriate amount of Nb to the steelmaking composition. The purpose is to have two points: On the one hand, when Nb is contained in the oriented silicon steel, it is easier to complete the nitriding at high temperature annealing. This is because the electron filling of the sub-dilayer sub-layer of the Nb atom is less saturated with respect to Fe and Mn, so that nitride formation is easier and the nitride is more stable.
• this part of the nitrogen atoms which are infiltrated during high-temperature annealing can form the main inhibitor A1N necessary for high magnetic flux density oriented silicon steel with Als, and can simultaneously obtain precipitates in the form of Nb 2 N and NbN.
• This part of Nb nitride can act as an auxiliary suppression (J, which enhances the effect of suppressing the growth of normal grains, and finally improves the magnetic properties of the oriented silicon steel finished board.
• an appropriate amount of NH 4 C1 and P 3 N 5 is added to the MgO coating liquid.
• the purpose is to use nitriding in the high temperature annealing process to complete nitriding into the plate, thereby replacing the nitriding by ammonia decomposition during the decarburization annealing process, and the greatest benefit is to ensure more uniform nitriding in the plate.
• the two inorganic nitrides, NH 4 C1 and P 3 N 5 are selected as the nitriding raw material for pyrolysis. Because the decomposition temperature of NH 4 C1 is 330 ⁇ 340 °C, and the decomposition temperature of P 3 N 5 is about 760 °C.
• Different nitride decomposition temperature regions ensure that the active nitrogen atoms are uniformly released over a long period of time during high-temperature annealing, thereby completing nitriding into the steel sheet and maintaining the nitrogen content [N] at 200-250 ppm. Within the standard range.
• the present invention requires control of the secondary heating rate during high temperature annealing.
• the purpose is to ensure excellent magnetic properties of the final product by setting an appropriate secondary heating rate. This is because the temperature range of secondary recrystallization of oriented silicon steel is covered during the secondary heating of high temperature annealing. Therefore, a suitable heating rate can make the Gaussian grain orientation which grows in the secondary recrystallization process better, the off angle is ⁇ 3 °, and the magnetic properties are better.
• the relatively slow temperature rise ensures the secondary recrystallization is perfect, and the finished product has good magnetic properties. This is because secondary recrystallization occurs during the secondary temperature rise of the high temperature annealing, and this is also the process in which the A1N inhibitor is coarsened and decomposed, and the inhibition force disappears. If it is within this temperature range, if the heating rate is too fast, the secondary recrystallization will not be completed, but the inhibitor will be decomposed and failed, the secondary recrystallization of the finished product is imperfect, and the magnetic deterioration is serious.
• the chemical compositions described in Table 1 were smelted and cast.
• the slabs of different compositions were placed in a heating furnace at 1155 ° C for 1.5 hours and then hot rolled to a hot rolled sheet having a thickness of 2.3 mm.
• the rolling and finishing temperatures were 1062 ° C and 937 ° C, respectively.
• a two-stage normalization is applied to the hot rolled sheet: (1120 °C xl 5sec) + (870 °C xl 50sec), followed by cooling at -15 °C/sec. After pickling, it is cold rolled to a thickness of 0.30 mm.
• decarburization annealing was carried out at a heating rate of 25 ° C/sec, a decarburization temperature of 820 ° C, and an average temperature of 140 s.
• a separator containing MgO as a main component and containing 4.5% NH 4 C1 and 15% P 3 N 5 was applied.
• the temperature is first raised to 800 ° C to obtain a nitrogen content b before the second temperature rise; the temperature is further raised to 1200 ° C, and then the temperature is maintained for 20 hours for purification annealing. After unwinding, it is coated with an insulating coating and stretched and flattened. Among them, the nitrogen content b before the second temperature rise and the magnetic properties of the finished product are shown in Table 1.
• the composition and weight percentage of the oriented silicon steel slab are C: 0.050%, Si: 3.25%, Mn: 0.15%, S: 0.009%, Als: 0.032%, N: 0.005%, Sn: 0.02%, Nb: 0.5%
• the rest are Fe and inevitable impurities.
• the slab was placed in a heating furnace at 1155 ° C for 1.5 hours and then hot rolled to a hot rolled sheet having a thickness of 2.3 mm.
• the rolling and finishing temperatures were 1080 ° C and 910 ° C, respectively.
• Two-stage normalization is applied to the hot rolled sheet: (1110 °C x l0sec) + (910 °C x l20sec), followed by cooling at -35 °C / sec.
• decarburization annealing was carried out at a heating rate of 25 ° C / sec, a decarburization temperature of 840 ° C, and an average temperature of 130 s.
• the coating is mainly composed of MgO, and different contents of NH 4 C1 and P 3 N 5 are added .
• annealing at a high temperature the temperature is first raised to 800 ° C to obtain a nitrogen content b before the second temperature rise; the temperature is further raised to 1200 ° C, and then the temperature is kept for 20 hours for purification annealing. After unwinding, it is coated with an insulating coating and stretched and flattened. Among them, the nitrogen content b before the second temperature rise and the magnetic properties of the finished product are shown in Table 2.
• composition and weight percentage of the oriented silicon steel slab are C: 0.050%, Si: 3.25%, Mn: 0.15%, S: 0.009%, Als: 0.032%, N: 0.005%, Sn: 0.02%, Nb content (a ) : 0.2-0.8%, the rest is Fe and unavoidable impurities.
• the slab was placed in a heating furnace at 1115 ° C for 2.5 hours and then hot rolled to a hot rolled sheet having a thickness of 2.3 mm, and the rolling and finishing temperatures were 1050 and 865 ° C, respectively.
• the two-stage normalization was applied to the hot rolled sheet: (1120 ° C x 15 sec) + (900 ° C x l20 sec), followed by cooling at -25 ° C / sec. After pickling, it is cold rolled to a thickness of 0.30 mm. Then, decarburization annealing was carried out at a heating rate of 25 ° C / sec, a decarburization temperature of 850 ° C, and an average temperature of 115 s.
• the coating was mainly composed of MgO, and 7.5% NH 4 C1 and 12.5% P 3 N 5 were added .
• the temperature is first raised to 700 ° C to 900 ° C, as the initial temperature (c) of the second temperature rise, and the nitrogen content before the second temperature rise (b) is obtained. Then heat up to 1200 with a certain secondary heating rate (V) . C, and then heat-treating for 20 hours for purification annealing. After unwinding, it is coated with an insulating coating and stretched and flattened.
• the Nb content (a), the pre-heating pre-nitrogen content (b), and the secondary heating initiation temperature (c) are the same;
• the actual secondary heating rate in the embodiment is 9 °C/hr 17 °C/hr, and the difference between the theoretical value and the actual value is positive, the magnetic properties of the finished product are better;
• the comparative example is reversed, so the magnetic properties of the finished board are poor.
• the high magnetic induction oriented silicon steel produced by the low temperature slab heating technology has the advantages of long life of the heating furnace, low energy consumption and low cost.
• the present invention is a novel high magnetic flux density oriented silicon steel production method based on a low temperature slab heating process, which effectively solves the above problems. It is characterized in that by adding a suitable Nb content in the steel making, the steel sheet is more likely to absorb nitrogen during the high-temperature annealing process; by adding a nitrogen-containing compound to the MgO separating agent, it is thermally decomposed during the high-temperature annealing process to reach the steel sheet. The purpose of uniform nitriding.
• the temperature rise rate is controlled according to the Nb content, the nitrogen content, and the secondary temperature rise temperature in the steel, thereby ensuring the secondary recrystallization is completed, and finally obtaining a high magnetic flux density oriented silicon steel product excellent in magnetic properties.

Landscapes

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

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=45891877

Family Applications (1)

Country Status (8)

Cited By (1)

Families Citing this family (19)

Citations (5)

Family Cites Families (21)

• 2010
  • 2010-09-30 CN CN2010102989547A patent/CN102443736B/zh active Active
• 2011
  • 2011-04-14 JP JP2013530534A patent/JP5864587B2/ja active Active
  • 2011-04-14 WO PCT/CN2011/072768 patent/WO2012041054A1/zh active Application Filing
  • 2011-04-14 RU RU2013114861/02A patent/RU2552562C2/ru active
  • 2011-04-14 MX MX2013003367A patent/MX350000B/es active IP Right Grant
  • 2011-04-14 EP EP11827950.4A patent/EP2623621B1/de active Active
  • 2011-04-14 US US13/823,424 patent/US20130233450A1/en not_active Abandoned
  • 2011-04-14 KR KR1020137008095A patent/KR101451824B1/ko active IP Right Grant

Patent Citations (5)

Also Published As

Similar Documents

Legal Events