CN111334653B - High magnetic induction oriented silicon steel and preparation method thereof - Google Patents

Abstract

The invention discloses high magnetic induction oriented silicon steel and a preparation method thereof, wherein the high magnetic induction oriented silicon steel comprises the following chemical components in percentage by weight: c: 0.015% -0.095%, Si: 2.80% -3.60%, Als: 0.010% -0.020%, N: 0.0080% -0.0100%, Mn: 0.030-0.150%, S: 0.0030 to 0.0150 percent, one or more of P, Cu, Sb, Sn, Cr, Bi and As are added, the content of (P + Cu + Sb + Sn + Cr + Bi + As) is less than or equal to 0.80 percent, and the balance of iron and inevitable impurities. The method prepares the high magnetic induction oriented silicon steel by hot rolling, normalizing, cold rolling, decarburization annealing, coating of an isolation coating, high-temperature annealing and stretching and flattening annealing, and ensures that the performance of a finished product can obtain the magnetic induction intensity B with the thickness of 0.30mm₈₀₀Not less than 1.935T, iron loss P_17/50The finished steel plate of the oriented silicon steel with the weight less than or equal to 1.02W/kg has the performance B compared with the conventional oriented silicon steel₈₀₀The T is improved by 0.02T, and the P17/50 is reduced by 0.1W/kg.

Description

High magnetic induction oriented silicon steel and preparation method thereof

Technical Field

The invention relates to the technical field of oriented electrical steel production, in particular to high-magnetic-induction oriented silicon steel and a preparation method thereof.

Background

In order to improve the power generation efficiency of a large-scale generator set, a large number of motor manufacturing enterprises select high-magnetic induction oriented silicon steel to manufacture stator cores of the motor, and the large-scale generator set can be widely applied to generator sets of large-scale thermal power, nuclear power, wind power and the like. The stator core needs to use high magnetic induction oriented silicon steel in the manufacturing process, and the performance of the oriented silicon steel can only be ensured by meeting the standard of a generator set.

The patent literature on high magnetic induction grain-oriented silicon steel and the preparation method thereof is mainly referred as follows:

chinese patent No. 200810222026.5 discloses a method for producing a low-temperature heating oriented electrical steel. Heating the casting blank at 1050-1100 ℃, and then hot rolling the casting blank into a hot rolled plate with the thickness of 1.5-3.0 mm, wherein the initial rolling temperature is 900-1100 ℃, and the final rolling temperature is 850-950 ℃; coiling at high temperature of 650-750 ℃, and quenching or preserving heat for 10 min-2 h after coiling; then, carrying out primary or secondary cold rolling with intermediate annealing to the thickness of a finished product, wherein the final total reduction rate is 80-90%; then decarbonizing, annealing, nitriding, coating MgO separant and annealing at high temperature to obtain a final product; the casting blank comprises the following components: c: 0.005-0.08%, Si: 2.5-6.5%, Als: 0.015 to 0.04%, Mn: 0.001-0.4%, Cu: 0.01-1.0%, S is less than or equal to 0.03%, P is less than or equal to 0.02%, N: 0.003-0.010% of Fe and inevitable impurities in balance; are all in mass percent.

Chinese patent with application number CN200410099080.7 discloses an oriented silicon steel and a production method and a device thereof, which comprises the following components (by weight percent): c: 0.035 to 0.060%, Si: 2.5-3.5%, Mn: 0.08-1.8%, S: 0.005-0.010%, Als: 0.015-0.035%, N: 0.0050 to 0.0090%, Sn: 0.01-0.15%, P: 0.010-0.030%, Cu: 0.05-0.12% and the balance Fe. The production method comprises the following steps: a. smelting; b. hot rolling, wherein a casting blank is heated to 1100-1200 ℃, the initial rolling temperature is less than 1200 ℃, the final rolling temperature is above 850 ℃, and the coiling temperature is below 650 ℃; c. normalizing, namely performing normalization annealing on the hot rolled plate at 1050-1180 ℃ (1-20 s) and 850-950 ℃ (30-200 s), and rapidly cooling; d. cold rolling, namely rolling the steel plate to the thickness of a finished plate by using a primary or more than two cold rolling methods with intermediate annealing; e. nitriding, decarbonizing, coating a high-temperature annealing separant taking MgO as a main component; high temperature annealing and hot leveling annealing.

Chinese patent No. 201110444436.6 discloses a general oriented silicon steel produced by continuous casting and rolling of thin slabs and a method for manufacturing the same. The components and weight percentage are as follows: c: 0.015 to 0.055%, Si: 2.5-4.0%, Mn: 0.10-0.40%, P is less than or equal to 0.025 t%, S is less than or equal to 0.010%, Als: 0.010-0.025%, N: 0.0065-0.0075%, Cu: 0.30-0.60%, and the balance of Fe and inevitable impurities; the method comprises the following steps: smelting and adopting thin slab continuous casting and rolling; carrying out acid washing and first cold rolling; in the presence of moisture-containing N₂、H₂Carrying out intermediate complete decarburization annealing in the atmosphere; performing second cold rolling to the required thickness; in N₂、H₂Performing recovery annealing, coating a magnesium oxide release agent, performing high-temperature annealing, performing flattening stretching and coating an insulating layer in the atmosphere. The patent uses AlN and epsilon-Cu as inhibitors to reduce the solid solution temperature of the inhibitors, and the subsequent procedures do not need normalization and nitridation, thereby reducing the production cost and obtainingThe product performance is uniform.

The Chinese patent with the application number of 201110033117.6 discloses a production method of high magnetic induction oriented silicon steel, which comprises the following steps:

a) producing a plate blank by steelmaking and continuous casting, wherein the plate blank comprises the following components in percentage by weight: c: 0.05-0.10%, Si: 2.5-4.0%, S: 0.008-0.028%, Als: 0.008-0.040%, N: 0.004-0.012%, Mn: 0.08-0.20%, Cu: 0.08-0.30% of Fe and inevitable impurities as the rest;

b) carrying out hot rolling on the plate blank after heat preservation at the temperature of not higher than 1250 ℃ in a heating furnace, wherein the final rolling temperature is more than 850 ℃;

c) annealing, pickling and cold rolling for one time or cold rolling for two times including intermediate annealing are carried out on the hot rolled plate until the thickness of a finished product is reached;

d) decarburization annealing is carried out on the cold-rolled sheet, namely the cold-rolled sheet is heated to a soaking temperature of 800-880 ℃, heat preservation is carried out in a wet nitrogen-hydrogen protective atmosphere, the heat preservation time is not more than 5 minutes, and the average grain diameter of the steel plate after decarburization annealing is 13-29 mu m;

e) coating an annealing release agent taking magnesium oxide as a main component, and then carrying out high-temperature annealing;

f) nitriding treatment is carried out after the final cold rolling and before secondary recrystallization of high-temperature annealing;

g) coating an insulating coating, and performing stretching, leveling and annealing.

The components or processing method of the above patents are as follows:

the Chinese patent with the application number of 200810222026.5 is subjected to primary or secondary cold rolling, and nitriding treatment is required to be carried out before secondary recrystallization through high-temperature annealing, so that the production cost is increased;

the Chinese patent with the application number of 200410099080.7 is subjected to primary or secondary cold rolling, and nitriding treatment is also required, so that the production cost is increased;

although the nitriding treatment is not needed, the secondary cold rolling is needed in the Chinese patent with the application number of 201110444436.6, so that the production yield is reduced, and the production cost is increased;

the chinese patent No. 201110033117.6 is subjected to one cold rolling or two cold rolling including intermediate annealing, and also subjected to nitriding treatment after the final cold rolling and before the secondary recrystallization by high-temperature annealing, thereby increasing the production cost.

The above patents all need to adopt secondary cold rolling and nitriding treatment to improve the performance of silicon steel, but reduce the production yield, increase the production cost and generate great difficulty in the production process.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides high-magnetic-induction oriented silicon steel and a preparation method thereof. The method takes AlN As a main inhibitor, reduces the hot rolling heating temperature of a plate blank by reducing the solid solubility product of Als, N, Mn and S, adds a small amount of P, Cu, Sb, Sn, Cr, Bi and As (P + Cu + Sb + Sn + Cr + Bi + As is less than or equal to 0.80%) As an auxiliary inhibitor in the steelmaking process, performs low-temperature hot rolling (less than or equal to 1280 ℃) and normalizing treatment of 1050 ℃ -1150 ℃ of a hot rolled plate, and obtains the magnetic induction strength B of a nitrided finished steel plate (with the thickness of 0.30mm) without performing primary cold rolling, decarburization annealing, magnesium oxide coating and isolation coating and high-temperature annealing₈₀₀Not less than 1.935T, iron loss P_17/50≤1.02W/kg。

In order to achieve the purpose, the invention designs high magnetic induction oriented silicon steel, which comprises the following chemical components in percentage by weight: c: 0.015% -0.095%, Si: 2.80% -3.60%, Als: 0.010% -0.020%, N: 0.0080% -0.0100%, Mn: 0.030 to 0.150%, S: 0.0030 to 0.0150 percent, one or more of P, Cu, Sb, Sn, Cr, Bi and As are added, the content of (P + Cu + Sb + Sn + Cr + Bi + As) is less than or equal to 0.80 percent, and the balance of iron and inevitable impurities.

Further, the high-magnetic-induction oriented silicon steel comprises the following chemical components in percentage by weight: c: 0.015% -0.095%, Si: 2.80% -3.60%, Als: 0.010% -0.020%, N: 0.0080% -0.0100%, Mn: 0.030 to 0.150%, S: 0.0050-0.0150%, adding one or more of P, Cu, Sb, Sn, Cr, Bi and As, wherein (P + Cu + Sb + Sn + Cr + Bi + As) is less than or equal to 0.80%, and the balance of iron and inevitable impurities.

Still further, the high-magnetic-induction oriented silicon steel comprises the following chemical components in percentage by weight: c: 0.085%, Si: 3.25%, Als: 0.0145%, N: 0.0082%, Mn: 0.095%, S: 0.0086%, Bi: 0.0071%, P: 0.0148%, Cu: 0.022%, Sn: 0.0052%, Sb: 0.0014%, Cr: 0.014%, As: 0.0054%; the balance of iron and inevitable impurities.

Still further, the high-magnetic-induction oriented silicon steel comprises the following chemical components in percentage by weight: c: 0.055%, Si: 3.28%, Als: 0.0148%, N: 0.0088%, Mn: 0.098%, S: 0.0077%, Bi: 0.0068%, P: 0.0121%, Cu: 0.022%, Sn: 0.0058%, Sb: 0.0012%, Cr: 0.018%, As: 0.0054%; the balance of iron and inevitable impurities.

Still further, the high-magnetic-induction oriented silicon steel comprises the following chemical components in percentage by weight: c: 0.055%, Si: 3.23%, Als: 0.0149%, N: 0.0087%, Mn: 0.097%, S: 0.0079%, Bi: 0.0077%, P: 0.0134%, Cu: 0.026%, Sn: 0.0054%, Sb: 0.0013%, Cr: 0.018%, As: 0.0061%; the balance of iron and inevitable impurities.

Still further, the thickness of the high magnetic induction oriented silicon steel is 0.30mm, and the magnetic induction intensity B of the high magnetic induction oriented silicon steel₈₀₀Not less than 1.935T, iron loss P_17/50≤1.02W/kg。

The invention also provides a preparation method of the high magnetic induction oriented silicon steel, which is used for preparing the high magnetic induction oriented silicon steel by hot rolling, normalizing, cold rolling, decarburization annealing, coating of an isolation coating, high-temperature annealing and stretching and flattening annealing, wherein,

1) hot rolling, namely performing low-temperature heating hot rolling, wherein the heating temperature of the hot rolling is 1100-1280 ℃, the finishing temperature is 850-1100 ℃, the thickness of a hot rolled plate is 2.0-2.8 mm, and the plate temperature is less than or equal to 600 ℃ for coiling;

2) normalizing: and preserving the heat for 30-180 s at 1050-1150 ℃.

3) Cold rolling: and (3) performing at least one time of aging rolling by adopting a primary rolling method, wherein the aging temperature is 160-.

4) Decarburization annealing and barrier coating: the decarburization annealing temperature is 750-900 ℃, the heat preservation is 60-180 s, the dew point is 25 ℃, the protective gas is a mixed gas of H2 and N2, the volume content of H2 is 15-80%, and the high-temperature annealing separant taking MgO as a main component is coated after decarburization annealing.

5) High-temperature annealing: and (3) performing a conventional high-temperature annealing process to finish secondary recrystallization and steel purification.

6) Stretching, flattening and annealing: and finishing the stretching, flattening, annealing and coating an insulating coating to obtain the high-magnetic-induction oriented silicon steel.

The principle of the invention is as follows:

1) the high magnetic induction oriented silicon steel has the advantages of chemical components:

c and carbon are important elements for manufacturing the oriented silicon steel, when the C content is less than 0.03 percent, particularly when the C content is less than 0.02 percent, the 3.25 percent Si steel with the C content is not transformed, crystal grains of a casting blank are obviously coarsened when the casting blank is heated, deformed crystal grains of a hot-rolled strip in the central area of the strip in the thickness direction are thick, fiber texture is strong in the area of <110>, deformed crystal grains remain after cold rolling and decarburization annealing, secondary recrystallization is incomplete after high-temperature annealing, the magnetism is reduced, but the carbon content is too high, the decarburization is difficult, and therefore, the carbon content is 0.015 to 0.095 percent;

si is added into the oriented electrical steel to increase the resistivity and reduce the iron loss, but the increase of the Si content can cause the processing brittleness, so the Si content is controlled between 2.80 percent and 3.60 percent to ensure the processability;

mn and S are auxiliary inhibitor forming elements, the content of Mn and S is reduced, and the solid solubility product of [ Mn multiplied by S ] can be reduced, so that large-particle MnS in a casting blank can be subjected to solid solution under the heating condition of no more than 1280 ℃, and beneficial second-phase particles of small-particle MnS are precipitated and formed in the rolling process, so that the content of Mn is 0.030-0.150%, and the content of S is 0.0050-0.0150%;

als and N are forming elements of an inhibitor AlN, the invention emphasizes the heating and hot rolling of a low-temperature plate blank at 1100-1280 ℃, and in order to ensure that large-particle AlN in a casting blank can be subjected to solid solution under the heating condition of no more than 1280 ℃, the content of Als is 0.010-0.020%, the content of N is 0.0080-0.0100%, and the content of N/Als is not less than 0.40, the value of N/Als is improved under the condition of complete solid solution, the invention is more favorable for forming fine-particle AlN second phase particles, the inhibition force of the initial recrystallization annealing and the secondary recrystallization annealing starting stage is improved, and the performance of a finished product is ensured;

p, Cu, Sb, Sn, Cr, Bi, As and the like are interface enrichment elements, and are easy to enrich in phase boundaries and grain boundaries, so that the growth of second phases and matrix grains is prevented.

2) Advantages of the manufacturing process

And (2) hot rolling, wherein the heating temperature ST of the steel billet is controlled to be not less than 1100 ℃ and not more than 1280 ℃, the heating temperature is 1100-1280 ℃, the finishing temperature is 850-1100 ℃, the hot rolling is carried out in a higher temperature zone range, the higher finishing temperature ensures that large-particle second phase particles such as AlN (aluminum nitride) and the like are not separated out in the hot rolling process, the thickness of the hot rolled plate is 2.0-2.8 mm, and the hot rolled plate is coiled at not more than 600 ℃.

Normalizing the hot rolled plate, and normalizing the hot rolled plate by keeping the temperature at 1050-1150 ℃ for 30-180 s to ensure that AlN second phase particles with proper size (capable of completing solid solution) complete solid solution to form favorable second phases. Normalizing at a temperature lower than 1050 ℃, wherein AlN is difficult to dissolve due to low temperature; the coarsening of the steel strip grains above 1150 ℃ leads to the growth of grains after primary recrystallization annealing and increases the production cost.

Decarburization annealing, wherein the temperature of the decarburization annealing is 750-900 ℃, the temperature is kept for 60-180 s, the dew point is 25 ℃, and the protective atmosphere is wet H₂And N₂Mixed gas of H₂Volume content: 15-80%, the purpose of decarburization annealing is as follows: the primary recrystallization is carried out so that a sufficient amount of [110 ] is present in the matrix](001) Grains (secondary nuclei) and primary recrystallization texture and texture that facilitates their growth; the carbon in the steel is removed to be below 0.0030 percent, and the high-temperature annealing is ensured to be in a single alpha phase; forming compact and uniform SiO on the surface of the steel strip₂A film.

Coating a high-temperature annealing release agent which takes MgO as a main component.

High-temperature annealing is carried out to complete secondary recrystallization, steel purification and the like.

And (4) stretching, flattening and annealing, finishing stretching, flattening and annealing and coating an insulating coating to obtain a finished product of the oriented electrical steel sheet.

The invention has the beneficial effects that: the invention reduces the hot rolling heating temperature of the plate blank by reducing the solid solubility product of Als, N, Mn and S, controls N/Als to be more than or equal to 0.40 under the condition of complete solid solution, singly or compositely adds one or more of P, Cu, Sb, Sn, Cr, Bi and As, improves the Als to 0.014% by low-temperature hot rolling at 1100-1280 ℃ and normalizing treatment at 1050-1150 ℃ of the hot rolled plate, reduces the normalizing time, is beneficial to forming fine-grained AlN second phase particles, improves the inhibiting force of the initial recrystallization annealing and secondary recrystallization annealing starting stages, and ensures that the magnetic induction intensity B with the thickness of 0.30mm can be obtained by the performance of the finished product after primary cold rolling, decarburization annealing, magnesium oxide isolation coating, high-temperature annealing, stretching and flattening annealing and insulating coating₈₀₀Not less than 1.935T, iron loss P_17/50The finished steel plate of the oriented silicon steel with the weight less than or equal to 1.02W/kg has the performance B compared with the conventional oriented silicon steel₈₀₀The T is improved by 0.02T, and the P17/50 is reduced by 0.1W/kg.

Detailed Description

The present invention is described in further detail below with reference to specific examples so as to be understood by those skilled in the art.

The high magnetic induction oriented silicon steel comprises the following chemical components in percentage by weight: c: 0.015% -0.095%, Si: 2.80% -3.60%, Als: 0.010% -0.020%, N: 0.0080% -0.0100%, Mn: 0.030-0.150%, S: 0.0030 to 0.0150 percent, one or more of P, Cu, Sb, Sn, Cr, Bi and As are added, the content of (P + Cu + Sb + Sn + Cr + Bi + As) is less than or equal to 0.80 percent, and the balance of iron and inevitable impurities.

The preparation method of the high magnetic induction oriented silicon steel comprises the steps of hot rolling, normalizing, cold rolling, decarburization annealing, barrier coating, high-temperature annealing and stretching and flattening annealing to prepare the high magnetic induction oriented silicon steel, wherein,

1) and (3) hot rolling, namely performing low-temperature heating hot rolling, wherein the heating temperature of the hot rolling is 1100-1280 ℃, the finishing temperature is 850-1100 ℃, the thickness of the hot rolled plate is 2.0-2.8 mm, and the plate temperature is less than or equal to 600 ℃ for coiling.

2) Normalizing: and preserving the heat for 30-180 s at 1050-1150 ℃.

3) Cold rolling: and (3) performing at least one time of aging rolling by adopting a primary rolling method, wherein the aging temperature is 160-.

4) Decarburization annealing and barrier coating: the decarburization annealing temperature is 750-900 ℃, the heat preservation is 60-180 s, the dew point is 25 ℃, and the protective gas is H₂And N₂Mixed gas of H₂The volume content is 15-80%, and after decarburization annealing, a high-temperature annealing separant taking MgO as a main component is coated.

5) High-temperature annealing: and (3) performing a conventional high-temperature annealing process to finish secondary recrystallization and steel purification.

6) Stretching, flattening and annealing: and finishing the stretching, flattening, annealing and coating an insulating coating to obtain the high-magnetic-induction oriented silicon steel.

According to the formula and the preparation method, the values of the chemical components of the high-magnetic-induction oriented silicon steel are designed by combining the practical situation:

TABLE 1 tabulated values (wt%) for inventive and comparative examples

	C	Si	Mn	Als	N	S	Bi	P	Cu	Sn	Sb	Cr	As
														Comparative example 1	0.055	3.23	0.092	0.0083	0.0085	0.0072	0.0072	0.0120	0.023	0.0060	0.0018	0.014	0.0054
Comparative example 2	0.057	3.19	0.096	0.0216	0.0080	0.0066	0.0078	0.0134	0.021	0.0056	0.0013	0.019	0.0062
														Example 1	0.058	3.25	0.095	0.0145	0.0082	0.0086	0.0071	0.0148	0.022	0.0052	0.0014	0.014	0.0054
Example 2	0.055	3.28	0.098	0.0148	0.0088	0.0077	0.0068	0.0121	0.022	0.0058	0.0012	0.018	0.0054
														Example 3	0.055	3.23	0.097	0.0149	0.0087	0.0079	0.0077	0.0134	0.026	0.0054	0.0013	0.018	0.0061
Example 4	0.058	3.24	0.090	0.0166	0.0088	0.0088	0.0069	0.0142	0.025	0.0055	0.0014	0.016	0.0052
														Example 5	0.057	3.20	0.091	0.0188	0.0089	0.0096	0.0068	0.0112	0.029	0.0052	0.0018	0.013	0.0056
Comparative example 3	0.056	3.22	0.092	0.0155	0.0088	0.0076	0.0062	0.0118	0.446	0.1230	0.2213	0.128	0.0054

As can be seen from Table 1, in comparative example 1, Als is less than 0.010%, the content of Als is low, the precipitation amount of AlN after decarburization is reduced, the inhibition force in high-temperature annealing is reduced, and the magnetic performance of a finished product is reduced; in the comparative example 2, Als is more than 0.020%, the solid solubility product of Als and N is high, and the Als and N are difficult to completely dissolve under the heating condition of 1100-1280 ℃, so that the effective precipitation quantity after decarburization is reduced, the inhibition force in primary recrystallization annealing and high-temperature annealing is reduced, and the magnetic performance of a finished product is reduced; in the comparative example 3, (P + Cu + Sb + Sn + Cr + Bi + As) > 0.80%, the content of interface enrichment elements is too high, hot rolling edge cracks are extremely large, and the production is difficult to smoothly develop.

TABLE 2 List of the main process parameters of the examples of the invention and the comparative examples

Comparative example 1, the hot rolling heating temperature is less than 1100 ℃, the final rolling temperature is less than 850 ℃, AlN cannot be completely dissolved in the heating process, the final rolling temperature is lower, large-particle AlN is separated out, effective AlN separation is reduced, the normalizing time is less than 30s, small-particle AlN cannot be completely dissolved, the effective separation quantity is reduced after decarburization annealing, so that the inhibition force in high-temperature annealing is reduced, and the magnetic performance of a finished product is reduced; comparative example 2, the hot rolling heating temperature is more than 1280 ℃, the heating temperature is higher, the crystal grain size of the casting blank grows, so the crystal grain size of the hot rolled plate and the primary recrystallization annealed plate grows, meanwhile, the heating temperature is higher, the burning loss of the casting blank is aggravated, the yield is reduced, the normalizing time is more than 180s, the normalizing time is too long, the precipitation, aggregation and coarsening are favorably caused, so the inhibition force in the post-process annealing is reduced, meanwhile, the heating time is too long, the crystal grain of the hot rolled plate grows, so the crystal grain size of the primary recrystallization annealed plate grows, and the magnetic performance of a finished product is reduced; in the comparative example 3, the normalizing temperature is less than 1050 ℃, the small and medium-sized AlN particles are difficult to be dissolved in solid, and the effective precipitation amount is reduced after decarburization annealing, so that the inhibition force in high-temperature annealing is reduced, and the magnetic performance of the finished product is reduced.

TABLE 3 List of the test results of the properties of each example of the present invention and comparative example (finished thickness 0.30mm)

In the comparative example 1, Als is less than 0.010 percent, the content of Als is low, the precipitation amount of AlN after decarburization is reduced, the inhibition force in high-temperature annealing is reduced, the hot rolling heating temperature is less than 1100 ℃, the final rolling temperature is less than 850 ℃, AlN cannot be completely dissolved in the heating process, the final rolling temperature is low, large-particle AlN is precipitated, effective precipitation of AlN is reduced, the normalizing time is less than 30s, small-particle AlN cannot be completely dissolved in the heating process, and the effective precipitation amount after decarburization annealing is reduced, so that the inhibition force in high-temperature annealing is reduced, and the magnetic performance of a finished product is reduced; in the comparative example 2, Als is more than 0.020%, the solid solubility product of Als and N is high, complete solid solution is difficult to realize under the heating condition of 1100-1280 ℃, the effective precipitation quantity after decarburization is reduced, the hot rolling heating temperature is more than 1280 ℃, the heating temperature is high, the crystal grain size of a casting blank grows, so that the crystal grain size of a hot rolled plate and a primary recrystallization annealing plate grows, meanwhile, the heating temperature is high, the burning loss of the casting blank is aggravated, the yield is reduced, the normalizing time is more than 180s, and the normalizing time is too long, so that precipitation aggregation and coarsening are facilitated, the inhibition force in the annealing of the post-working procedure is reduced, meanwhile, the heating time is too long, the crystal grain size of the hot rolled plate grows, and the magnetic performance of a finished product is reduced; in the comparative example 3, (P + Cu + Sb + Sn + Cr + Bi + As) > 0.80%, the content of interface enrichment elements is too high, hot rolling edge cracks are extremely large, and the production is difficult to smoothly develop.

Other parts not described in detail are prior art. Although the present invention has been described in detail with reference to the above embodiments, it is only a part of the embodiments of the present invention, not all of the embodiments, and other embodiments can be obtained without inventive step according to the embodiments, and the embodiments are within the scope of the present invention.

Claims (5)

1. A high magnetic induction oriented silicon steel is characterized in that: the high magnetic induction oriented silicon steel comprises the following chemical components in percentage by weight: c: 0.015% -0.095%, Si: 2.80% -3.60%, Als: 0.010% -0.020%, N: 0.0080% -0.0100%, Mn: 0.030 to 0.150%, S: 0.0050-0.0150%, adding one or more of P, Cu, Sb, Sn, Cr, Bi and As, wherein (P + Cu + Sb + Sn + Cr + Bi + As) is less than or equal to 0.80%, and the balance of iron and inevitable impurities; the thickness of the high-magnetic induction oriented silicon steel is 0.30mm, and the magnetic induction intensity B of the high-magnetic induction oriented silicon steel₈₀₀Not less than 1.935T, iron loss P_17/50≤1.02W/kg；The high magnetic induction oriented silicon steel is prepared by hot rolling, normalizing, cold rolling, decarburization annealing, coating of an isolation coating, high-temperature annealing and stretching and flattening annealing, wherein,

1) hot rolling, namely performing low-temperature heating hot rolling, wherein the heating temperature of the hot rolling is 1100-1280 ℃, the finishing temperature is 850-1100 ℃, the thickness of a hot rolled plate is 2.0-2.8 mm, and the plate temperature is less than or equal to 600 ℃ for coiling;

2) normalizing: preserving heat for 30-180 s at 1050-1150 ℃;

3) cold rolling: adopting a primary rolling method to perform at least one time of aging rolling, wherein the aging temperature is 160-;

4) decarburization annealing and barrier coating: the decarburization annealing temperature is 750-900 ℃, the heat preservation is 60-180 s, the dew point is 25 ℃, and the protective gas is H₂And N₂Mixed gas of H₂The volume content is 15-80%, and a high-temperature annealing separant taking MgO as a main component is coated after decarburization annealing;

5) high-temperature annealing: performing a conventional high-temperature annealing process to finish secondary recrystallization and steel purification;

6) stretching, flattening and annealing: and finishing the stretching, flattening, annealing and coating an insulating coating to obtain the high-magnetic-induction oriented silicon steel.

2. The high magnetic induction oriented silicon steel as set forth in claim 1, wherein: the high magnetic induction oriented silicon steel comprises the following chemical components in percentage by weight: c: 0.085%, Si: 3.25%, Als: 0.0145%, N: 0.0082%, Mn: 0.095%, S: 0.0086%, Bi: 0.0071%, P: 0.0148%, Cu: 0.022%, Sn: 0.0052%, Sb: 0.0014%, Cr: 0.014%, As: 0.0054%; the balance of iron and inevitable impurities.

3. The high magnetic induction oriented silicon steel as set forth in claim 1, wherein: the high magnetic induction oriented silicon steel comprises the following chemical components in percentage by weight: c: 0.055%, Si: 3.28%, Als: 0.0148%, N: 0.0088%, Mn: 0.098%, S: 0.0077%, Bi: 0.0068%, P: 0.0121%, Cu: 0.022%, Sn: 0.0058%, Sb: 0.0012%, Cr: 0.018%, As: 0.0054%; the balance of iron and inevitable impurities.

4. The high magnetic induction oriented silicon steel as set forth in claim 1, wherein: the high magnetic induction oriented silicon steel comprises the following chemical components in percentage by weight: c: 0.055%, Si: 3.23%, Als: 0.0149%, N: 0.0087%, Mn: 0.097%, S: 0.0079%, Bi: 0.0077%, P: 0.0134%, Cu: 0.026%, Sn: 0.0054%, Sb: 0.0013%, Cr: 0.018%, As: 0.0061%; the balance of iron and inevitable impurities.

5. A method for preparing the high magnetic induction oriented silicon steel as set forth in claim 1, which comprises the steps of hot rolling, normalizing, cold rolling, decarburization annealing, barrier coating, high temperature annealing and stretch leveling annealing, and is characterized in that:

1) hot rolling, namely performing low-temperature heating hot rolling, wherein the heating temperature of the hot rolling is 1100-1280 ℃, the finishing temperature is 850-1100 ℃, the thickness of a hot rolled plate is 2.0-2.8 mm, and the plate temperature is less than or equal to 600 ℃ for coiling;

2) normalizing: preserving heat for 30-180 s at 1050-1150 ℃;

3) cold rolling: adopting a primary rolling method to perform at least one time of aging rolling, wherein the aging temperature is 160-;

4) decarburization annealing and barrier coating: the decarburization annealing temperature is 750-900 ℃, the heat preservation is 60-180 s, the dew point is 25 ℃, and the protective gas is H₂And N₂Mixed gas of H₂The volume content is 15-80%, and a high-temperature annealing separant taking MgO as a main component is coated after decarburization annealing;

5) high-temperature annealing: performing a conventional high-temperature annealing process to finish secondary recrystallization and steel purification;

6) stretching, flattening and annealing: and finishing the stretching, flattening, annealing and coating an insulating coating to obtain the high-magnetic-induction oriented silicon steel.