阅读说明：本技术 高磁感取向钢的生产工艺 (Production process of high magnetic induction oriented steel ) 是由 杨林 王静 彭明山 邹红 吴路波 �田�浩 吴峰 皮统政 童鑫 陈林 曾兰兰 于 2019-10-31 设计创作，主要内容包括：本发明涉及钢材加工领域,具体公开了高磁感取向钢的生产工艺,包括硅钢连铸板坯加工步骤；硅钢连铸板坯的粗轧和精轧步骤；二段式常化步骤；冷轧加工步骤；脱碳退火步骤；氮化加工步骤；退火隔离剂涂覆步骤；高温退火步骤；绝缘涂层膜及拉伸退火步骤；激光刻痕步骤。本方案中的钢板在进行冷轧加工前,对钢板进行了粗轧、精轧以及常化加工,酸洗除磷和剪边,在进行冷轧加工时,钢板的表面不易出现裂边和断裂的事故,能够提升钢板的冷轧效率。(The invention relates to the field of steel processing, and particularly discloses a production process of high magnetic induction oriented steel, which comprises the steps of silicon steel continuous casting slab processing; rough rolling and finish rolling of the silicon steel continuous casting plate blank; a two-stage normalizing step; cold rolling; a decarburization annealing step; a nitriding processing step; an annealing release agent coating step; a high-temperature annealing step; an insulating coating film and a stretch annealing step; and (3) laser scoring. Before cold rolling processing is carried out on the steel plate, rough rolling, finish rolling and normalizing processing, acid pickling dephosphorization and edge shearing are carried out on the steel plate, and during cold rolling processing, the surface of the steel plate is not easy to have the accidents of edge cracking and fracture, so that the cold rolling efficiency of the steel plate can be improved.)

1. The production process of the high magnetic induction oriented steel is characterized by comprising the following steps of:

step 1: preparing steel for steelmaking, and carrying out steelmaking on the steel by adopting a converter or an electric furnace to obtain molten steel; carrying out vacuum degassing treatment on the molten steel to obtain a silicon steel continuous casting slab;

step 2: heating the silicon steel continuous casting slab at the temperature of 1150-1300 ℃ to enable the temperature of the silicon steel continuous casting slab to reach 1150-1300 ℃, then carrying out rough rolling on the silicon steel continuous casting slab to 40-70mm, and then carrying out fine rolling on the silicon steel continuous casting slab, wherein the cumulative reduction rate of the fine rolling is more than 90%;

and step 3: after the finish rolling, rapidly cooling the hot-rolled silicon steel plate, and then coiling the steel plate, wherein the temperature of the coiled steel plate is below 600 ℃;

and 4, step 4: normalizing the steel plate by adopting two-stage normalization;

and 5: performing cold rolling processing on the normalized steel plate, wherein the final reduction rate of the cold rolling is more than 80%, and the temperature of the steel plate is kept at 190-210 ℃ during the cold rolling;

step 6: introducing the cold-rolled steel plate into a continuous annealing furnace for decarburization annealing, adopting a protective atmosphere when the steel plate is heated to 770-900 ℃, and adopting the oxidation degree (P) of the protective atmosphere_H2O/P_H2)0.35-0.45, and the concentration of carbon element is less than or equal to 25ppm, and the concentration of oxygen element is 600-700 ppm;

and 7: after decarburization annealing, introducing ammonia gas with higher nitriding energy into the independent furnace section of the annealing furnace in the step 6, so that the ratio of the nitrogen element content in the steel plate to the aluminum element content in the steel plate is more than 2: 4;

and 8: coating an annealing release agent on the surface of the steel plate subjected to the nitriding treatment in the step 7;

and step 9: annealing the steel plate at high temperature to generate recrystallized grains with the orientation of {110} <100 >;

step 10: coating an insulating coating film on the surface of the steel plate subjected to high-temperature annealing, and then performing stretching annealing;

step 11: and carrying out laser scoring on the steel plate after the stretching annealing.

2. The process for treating high magnetic induction oriented steel according to claim 1, wherein in the step 2, the reduction ratio of the final pass of the finish rolling is 25% or more.

3. The process for treating high magnetic induction oriented steel according to claim 2, wherein in the step 2, the reduction ratio of the final pass of the finish rolling is 30% or more.

4. The process for treating high magnetic induction oriented steel according to claim 3, wherein in the step 4, when the steel plate is normalized by two-stage normalization, in the first stage of heating normalization, the temperature rise speed is 5-10 ℃/s, when the temperature rises to over 1100 ℃, the temperature is kept for 30 seconds, and then the temperature is immediately reduced; in the second stage of heating and normalizing, the annealing speed is more than or equal to 6 ℃/s, the crystal grain structure in the steel plate keeps the lamellar interval, and the cooling speed is 50 ℃/s.

5. The process of claim 4, wherein the grain structure in the steel plate is maintained at lamellar intervals, and the lamellar intervals reach 20 μm.

6. The process of claim 5, wherein in the step 7, after the nitriding treatment, the ratio of the content of nitrogen element in the steel plate to the content of aluminum element in the steel plate is greater than 2: 3.

7. The process of claim 6, wherein the thickness of the insulating coating film in step 10 is 4.0-5.0g/m²。

8. The process of claim 7, wherein the thickness of the insulating coating film in step 10 is 4.5g/m²。

9. The process as claimed in claim 8, wherein the temperature of the steel sheet in the cold rolling process is maintained at 195-205 ℃.

10. The process for treating high magnetic induction oriented steel according to claim 9, wherein in the step 6, the annealing separator is MgO annealing separator or TiO2 annealing separator.

Technical Field

The invention belongs to the field of steel processing, and particularly relates to a production process of high-magnetic-induction oriented steel.

Background

10 new steel materials including high-performance silicon steel are the key points of the development of China in the next three years, and meet the industrial policy of China and the requirement of upgrading and updating of the transformer industry, high-magnetic induction oriented electrical steel in the high-performance silicon steel is a necessary material required in the power industry, and the development of the power industry is determined by the performance and updating of the high-magnetic induction oriented electrical steel.

In the production process of the high magnetic induction oriented electrical steel, the steel plate is limited by the reduction rate in cold rolling, and when the reduction rate is too low, the cold rolling efficiency of the steel plate can be greatly influenced, and the processing efficiency of the high magnetic induction oriented electrical steel is influenced; however, when the reduction ratio is too high, the accidents of edge cracking and fracture often occur, the strip steel layer and the strip steel layer are easy to adhere, the production efficiency is affected, a large amount of iron loss is caused, the magnetic performance of the oriented silicon steel is not high, and the production cost of the high-magnetic-induction oriented electrical steel is increased.

Disclosure of Invention

The invention aims to provide a production process of high magnetic induction oriented steel capable of improving the cold rolling efficiency of a steel plate so as to improve the processing efficiency of the high magnetic induction oriented steel and reduce the iron loss of the high magnetic induction oriented steel.

In order to achieve the above object, the basic scheme of the invention is as follows: the production process of the high magnetic induction oriented steel comprises the following steps:

step 1: preparing steel for steelmaking, and carrying out steelmaking on the steel by adopting a converter or an electric furnace to obtain molten steel; carrying out vacuum degassing treatment on the molten steel to obtain a silicon steel continuous casting slab;

step 2: heating the silicon steel continuous casting slab at the temperature of 1150-1300 ℃ to enable the temperature of the silicon steel continuous casting slab to reach 1150-1300 ℃, then carrying out rough rolling on the silicon steel continuous casting slab to 40-70mm, and then carrying out fine rolling on the silicon steel continuous casting slab, wherein the cumulative reduction rate of the fine rolling is more than 90%;

and step 3: after the finish rolling, rapidly cooling the hot-rolled silicon steel plate, and then coiling the steel plate, wherein the temperature of the coiled steel plate is below 600 ℃;

and 4, step 4: normalizing the steel plate by adopting two-stage normalization;

and 5: performing cold rolling processing on the normalized steel plate, wherein the final reduction rate of the cold rolling is more than 80%, and the temperature of the steel plate is kept at 190-210 ℃ during the cold rolling;

step 6: introducing the cold-rolled steel plate into a continuous annealing furnace for decarburization annealing, heating the steel plate to 770-900 ℃, and adopting a protective atmosphere, wherein the oxidation degree (PH2O/PH2) of the protective atmosphere is 0.35-0.45, the concentration of carbon element is less than or equal to 25ppm, and the concentration of oxygen element is 600-700 ppm;

and 7: after decarburization annealing, introducing ammonia gas with higher nitriding energy into the independent furnace section of the annealing furnace in the step 6, so that the ratio of the nitrogen element content in the steel plate to the aluminum element content in the steel plate is more than 2: 4;

and 8: coating an annealing release agent on the surface of the steel plate subjected to the nitriding treatment in the step 7;

and step 9: annealing the steel plate at high temperature to generate recrystallized grains with the orientation of {110} <100 >;

step 10: coating an insulating coating film on the surface of the steel plate subjected to high-temperature annealing, and then performing stretching annealing;

step 11: and carrying out laser scoring on the steel plate after the stretching annealing.

The principle and advantages of the basic scheme are as follows: before the cold rolling in the step 3, the steel plate is subjected to rough rolling, finish rolling and normalizing, the cold rolling difficulty and strength during the cold rolling can be reduced after the rough rolling and the finish rolling, and meanwhile, after the finish rolling is adopted, the thickness of the silicon steel continuous casting plate blank is reduced, the silicon steel continuous casting plate blank can be cooled in time, the steel plate cannot be recrystallized, and the improvement of magnetic induction is facilitated; meanwhile, the surface tension of the steel plate is improved after normalization, and the surface of the steel plate is not easy to have the accidents of edge cracking and fracture during cold rolling processing; under the technical guarantee, when the temperature of the steel plate is kept at 190-210 ℃ during cold rolling processing in the step 5, the toughness of the steel plate is further improved, and the final reduction rate of the cold rolling is controlled to be more than 80 percent, so that the surface of the steel plate can not be cracked or broken, and the iron loss is reduced; and the processing efficiency of cold rolling can be improved, and the processing efficiency of the whole steel plate is improved.

Meanwhile, after the steel plate is annealed in the step 6, crystal grains in the steel plate can be refined, deformation and cracks on the steel plate can be further reduced, and meanwhile, the quality of nitrogen and aluminum in the steel plate is controlled in the step 7, so that the content of the nitrogen can be effectively controlled, and the processed high-magnetic-induction oriented electrical steel has the characteristics of wear resistance, fatigue resistance, corrosion resistance and high-temperature resistance.

Step 8 and step 9, by coating the annealing separant, recrystallized grains with the {110} <100> orientation can be effectively formed in the steel plate, the grains in the steel plate are further refined, the wear resistance, fatigue resistance, corrosion resistance and high temperature resistance of the steel plate are further improved, the preparation for the stretching annealing in the step 10 is also facilitated, and the accidents of edge cracking and fracture of the steel plate in the stretching annealing process are avoided.

Further, in step 2, the reduction ratio of the final pass of the finish rolling is 25% or more.

On the basis of processing the silicon steel continuous casting slab by rough rolling, the single reduction rate is higher during finish rolling, the number of finish rolling times can be reduced, and the processing efficiency of the whole rolling process is improved.

Further, in step 2, the reduction ratio of the final pass of the finish rolling is 30% or more.

When the reduction ratio of the final pass of the finish rolling is 30% or more, the processing efficiency of the rolling is further improved.

Further, in the step 4, when the steel plate is normalized by adopting two-stage normalization, in the first stage of heating normalization, the temperature rise speed is 5-10 ℃/s, when the temperature rises to more than 1100 ℃, the temperature is kept for 30 seconds, and then the temperature is immediately reduced; in the second stage of heating and normalizing, the annealing speed is more than or equal to 6 ℃/s, the crystal grain structure in the steel plate keeps the lamellar interval, and the cooling speed is 50 ℃/s.

By adopting multi-section normalizing processing, the dephosphorization of the steel plate can be more thorough, the subsequent cold rolling processing is more convenient, the grain structure in the steel plate keeps the layered interval, the steel plate can be extended in the horizontal direction when the subsequent cold rolling processing is convenient, and the risk of edge cracking and fracture is reduced.

Further, the grain structure in the steel sheet maintains a lamellar spacing, and the lamellar spacing reaches 20 μm.

The layered interval reaches a better state suitable for cold rolling, and is convenient for cold rolling processing.

Further, in step 7, after the nitriding treatment, the ratio of the nitrogen element content in the steel sheet to the aluminum element content in the steel sheet is greater than 2: 3.

The concentration of the carbon element in the protective atmosphere is far lower than that of the oxygen element, so that the oxygen element can quickly consume the carbon element in the steel plate when decarburization annealing is guaranteed, the decarburization efficiency is effectively improved, and meanwhile the carbon element in the protective atmosphere can be prevented from entering the steel plate.

Further, in step 10, the thickness of the insulating coating film is set so that the coating amount becomes 4.0 to 5.0g/m²。

The coating amount of the insulating coating film can ensure that the surface tension on the surface of the steel plate is increased, and the iron loss is reduced.

Further, in step 10, the thickness of the insulating coating film is such that the coating amount becomes 4.5g/m²。

Insulating coating film 4.5g/m²The coating amount of (2) can ensure that the tension on the surface of the steel plate is increased, and the waste of redundant insulating coating films is avoided.

Further, in step 5, the temperature of the steel sheet at the time of cold rolling was maintained at 195-.

The toughness of the steel plate is improved from the temperature, and the phenomena of edge cracking and fracture can not occur in cold rolling processing.

Further, in step 8, the annealing separator is MgO annealing separator or TiO2 annealing separator.

The use of the MgO annealing separator can enhance the annealing separation effect of the annealing separator.

Drawings

FIG. 1 is a schematic front view of a coating apparatus according to example 2 of the present invention;

FIG. 2 is an enlarged cross-sectional view of the coating mechanism of FIG. 1;

fig. 3 is a top view of the winding mechanism in fig. 1.

Detailed Description

The following is further detailed by the specific embodiments:

reference numerals in the drawings of the specification include: the device comprises a conveyor belt 10, a rectangular limit frame 101, a containing box 20, a flow guide pipe 201, a coating block 202, a coating hole 203, a flow guide cavity 204, a communication hole 205, a sponge 206, a support column 30, a reel 401, a support bearing 402, a spring rod 403, a pressure spring 404, a fixing plate 405 and a steel plate 60.