WO2021239057A1 - Thin-gauge oriented silicon steel plate having excellent manufacturability, and manufacturing method therefor - Google Patents

Abstract

Disclosed in the present invention is a thin-gauge oriented silicon steel plate having excellent manufacturability, which comprises the following chemical elements in percentage by mass: Si: 3.0-4.0%; C: 0.04-0.1%; Mn: 0.05-0.20%; S: 0.003-0.014%; Als: 0.015-0.04%; N: 0.001-0.010%; and at least one of Cr, Mo, V and W elements, which satisfy 0.03%≤Cr+Mo+W+V≤0.2%. Also disclosed in the present invention is a manufacturing method for the thin-gauge oriented silicon steel plate, comprising steps of: steelmaking, hot rolling, normalizing, cold rolling, decarburization-annealing, coating a high temperature isolator, coiling, high temperature annealing, and hot-drawing, levelling and annealing, wherein during coating of the high temperature isolator, the coating amount D is controlled to be 10-22 g/m²; during coiling, the coiling tension F is controlled to be 60-160 N/mm², and the two satisfy 10×D-100<F<10×D+20. The thin-gauge oriented silicon steel plate in the present invention adopts reasonable chemical components and process design, and has excellent manufacturability and electromagnetic properties.

Description

Thin-gauge oriented silicon steel sheet with excellent manufacturability and manufacturing method thereof Technical field

The invention relates to a metal material and a manufacturing method thereof, in particular to a thin-gauge oriented silicon steel plate and a manufacturing method thereof.

Background technique

The Si content of oriented silicon steel is between 3% and 4%. It is a soft magnetic functional material whose grain easy magnetization direction <001> is parallel to the rolling direction. It is mainly used to manufacture transformer cores. The general production process of oriented silicon steel is steelmaking, hot rolling, normalization, cold rolling, decarburization annealing, coating high temperature isolating agent, high temperature annealing, hot stretching flattening annealing, etc. The thickness of the finished product of oriented silicon steel is generally 0.23mm, 0.27mm and 0.30mm. In recent years, due to the advantages of low iron loss and excellent performance of thin gauge oriented silicon steel of 0.23mm and below, more and more oriented silicon steel manufacturers have begun to develop oriented silicon steel products with thicknesses of 0.20mm, 0.18mm or even 0.15mm.

However, the thin-gauge oriented silicon steel of 0.23mm and below has problems such as easy adhesion, cracking and deviation of the edges during the hot stretching and annealing process, which will cause the unit to stop and slow down, and the production efficiency and yield rate will be greatly reduced. There will be problems such as broken belt, inability to continue production, rollback, etc.; waste products such as parking spots, creases, or tail rolls will be generated, which greatly affects product quality. The manufacturability of thin-gauge oriented silicon steel in the hot-stretching and leveling unit is a key technical problem that affects the output and quality of the product.

Published in "World Steel", 1996, Issue 3, page 66-69, "The formation of adhesion and preventive measures during hood annealing of thin strip steel," it is believed that there are many influencing factors for the occurrence of adhesion. The annealing temperature of the bell-type furnace is comprehensively resolved. In addition, "Some Discussions on the Bonding of Bell-type Furnace Annealing Coils" published at the National Narrow Strip Production Technology Exchange Conference in 2003 (Tu Ming, Liu Jingjian) believed that the normal stress of the steel strip can be controlled to reduce the annealing steel. Strip surface roughness, control the holding time and the reduction rate in the rolling process, so that the annealing bond rate is reduced from 48% to 26% or less.

The above schemes are all aimed at ordinary cold plates, and it is difficult to solve the adhesion problems existing in thin-gauge oriented silicon steel plates. The main reasons are:

(1) The composition system and texture of grain-oriented silicon steel are quite different from those of conventional cold-rolled products, and the mechanical properties and thermal conductivity of the two are quite different;

(2) The maximum temperature of high-temperature annealing of oriented silicon steel is much higher than that of cold plate, reaching 1200℃ and above, and the bonding phenomenon is more serious.

The publication number is JP 2001-303137, the publication date is October 31, 2001, and the Japanese patent document titled "Production Method of Grain Oriented Silicon Steel with Excellent Coil Shape" discloses a method of controlling a high-temperature isolating agent The powder characteristics such as angle of repose, particle size and coiling tension are used to obtain oriented silicon steel sheet with excellent coil shape.

Summary of the invention

One of the objectives of the present invention is to provide a thin-gauge oriented silicon steel sheet with excellent manufacturability. The thin-gauge oriented silicon steel sheet can effectively improve the quality of the bottom layer of the substrate and reduce adhesion and deviation through reasonable chemical composition design. Thin gauge oriented silicon steel sheet has iron loss P _17/50 <0.8W/Kg, magnetic induction B ₈ >1.9T, finished product width>1000mm, roll weight>2t, and has good manufacturability and excellent electromagnetic properties. Among them, the thin-gauge oriented silicon steel sheet refers to the oriented silicon steel sheet with a thickness of 0.23mm and below.

In order to achieve the above object, the present invention provides a thin-gauge oriented silicon steel sheet with excellent manufacturability, which in addition to Fe also contains the following chemical elements in the following mass percentages:

Si: 3.0～4.0%, C: 0.04～0.1%, Mn: 0.05～0.20%, S: 0.003～0.014%, Als: 0.015～0.04%, N: 0.001～0.010%, and Cr, Mo, W, V At least one of the elements, and satisfies 0.03%≤Cr+Mo+W+V≤0.2%. Among them, Cr, Mo, V and W in the formula respectively represent the mass percentages of their respective corresponding elements.

Further, in the thin-gauge oriented silicon steel sheet of the present invention, the mass percentage of each chemical element is:

Si: 3.0～4.0%, C: 0.04～0.1%, Mn: 0.05～0.20%, S: 0.003～0.014%, Als: 0.015～0.04%, N: 0.001～0.010%, and Cr, Mo, W, V At least one of the elements, and satisfies 0.03%≤Cr+Mo+W+V≤0.2%, and the balance is Fe and other unavoidable impurities. Among them, Cr, Mo, V and W in the formula respectively represent the mass percentages of their respective corresponding elements.

In the thin-gauge oriented silicon steel sheet of the present invention, the design principles of each chemical element are as follows:

Si: In the thin-gauge oriented silicon steel sheet of the present invention, the Si element can effectively increase the resistivity of the material and reduce the iron loss of the steel. However, it should be noted that the higher the Si content in the steel, the worse the manufacturability. When the Si element content in the steel is higher than 4.0%, it will lead to an increase in the cold-rolled strip breaking rate; and if the Si content in the steel is lower than 3.0%, it cannot effectively reduce the iron loss and improve the performance. Therefore, in the thin-gauge oriented silicon steel sheet of the present invention, the mass percentage of Si is controlled to be between 3.0% and 4.0%.

C: In the thin-gauge oriented silicon steel sheet of the present invention, C mainly forms a γ phase during hot rolling. When the content of C element in the steel is less than 0.04%, an effective γ phase cannot be formed. However, it should be noted that if the C element content in the steel is too high, exceeding 0.1%, it will cause difficulties in decarburization. Therefore, the mass percentage of C in the thin-gauge oriented silicon steel sheet of the present invention is controlled to be between 0.04 and 0.1%.

Mn: In the thin-gauge oriented silicon steel sheet of the present invention, the role of the Mn element is similar to that of the Si element, and it can also increase the resistivity of the material and reduce the iron loss of the steel. In addition, Mn and S can combine to form MnS as an inhibitor. However, it should be noted that if the Mn content in the steel is less than 0.05%, the above-mentioned effect cannot be achieved, and when the Mn content in the steel is higher than 0.20%, the hot rolling workability and magnetic properties will be reduced. Therefore, the mass percentage of Mn in the thin-gauge oriented silicon steel sheet of the present invention is controlled to be between 0.05 and 0.20%.

S: In the thin-gauge oriented silicon steel sheet of the present invention, S is mainly combined with Mn, Cu, etc. to form MnS or CuS as an inhibitor. When the S content in the steel is less than 0.003%, the above-mentioned effect cannot be effectively performed, and if the S content in the steel is higher than 0.014%, it is difficult to purify and desulfurize. Therefore, the mass percentage of S in the thin-gauge oriented silicon steel sheet of the present invention is controlled to be between 0.003 and 0.014%.

Als: In the thin-gauge oriented silicon steel sheet of the present invention, Als mainly forms an AlN inhibitor with N. If the Als content in the steel is too high, the quality of the bottom layer will be deteriorated, and if the Als content in the steel is too low, it will not have the inhibitory effect. Therefore, the mass percentage of Als in the thin-gauge oriented silicon steel sheet of the present invention is controlled to be between 0.015 and 0.04%.

N: In the thin-gauge oriented silicon steel sheet of the present invention, N can form an AlN inhibitor with Als. If the N content in the steel is less than 0.001%, the inhibitor is insufficient, and if the N content in the steel is higher than 0.010%, the steel-making casting is easy to swell, and the product will have skin and blistering defects. Therefore, the mass percentage of N in the thin-gauge oriented silicon steel sheet of the present invention is controlled to be between 0.001 and 0.010%.

Cr, Mo, W, V: In the thin-gauge oriented silicon steel sheet of the present invention, the added elements of Cr, Mo, V and W are mainly to promote the oxidation of the strip surface during the decarburization annealing process and improve the quality of the bottom layer. If the addition amount of Cr, Mo, V and W elements is less than 0.03%, this effect cannot be achieved, and if the addition amount of Cr, Mo, V and W elements is more than 0.2%, the electromagnetic properties of the substrate will be deteriorated. . Therefore, the mass percentage of Cr, Mo, V and W elements added in the thin-gauge oriented silicon steel sheet of the present invention is controlled to be 0.03%≤Cr+Mo+W+V≤0.2%.

Furthermore, the mass percentage of Cr, Mo, V, and W elements added to the thin-gauge oriented silicon steel sheet of the present invention can be controlled to 0.05%≤Cr+Mo+W+V≤0.1%, and the magnetic properties and the quality of the underlying layer are even better. excellent.

Further, in the thin-gauge oriented silicon steel sheet of the present invention, its thickness is 0.15mm-0.23mm.

Further, in the thin-gauge oriented silicon steel sheet of the present invention, the iron loss P _17/50 <0.8 W/Kg, and the magnetic induction B ₈ > 1.9T.

Correspondingly, another object of the present invention is to provide a method for manufacturing thin-gauge oriented silicon steel sheet with excellent manufacturability, which can effectively solve the adhesion and deviation in the on-site production of thin-gauge oriented silicon steel. In terms of performance, the thin-gauge oriented silicon steel sheet produced by this manufacturing method has iron loss P _17/50 <0.8 W/Kg, and its magnetic induction B ₈ > 1.9T, which has good manufacturability and excellent electromagnetic properties.

In order to achieve the above-mentioned object, the present invention proposes the above-mentioned manufacturing method of thin-gauge oriented silicon steel sheet, which includes the steps of: steelmaking, hot rolling, normalization, cold rolling, decarburization annealing, coating high temperature isolating agent, coiling, high temperature annealing And thermal stretching and flattening annealing; among them, the normalization mentioned above is the annealing step; when coating high temperature release agent, control the coating amount D to 10-22g/m ² ; when coiling, control the coiling tension F is 60-160N/mm ² , and both satisfy 10×D-100<F<10×D+20.

In the thin-gauge oriented silicon steel sheet manufacturing method of the present invention, the process conditions, especially the coiling tension and the coating amount of the release agent, are designed to take into account that in the coiling step, the greater the coiling tension, the greater the coil Rolling too tight will lead to bonding, so the tension value should be reduced, which is good for reducing bonding, but it should not be too small, otherwise it will loosen the coil, and then the finished unit will run off during production, so the final coiling tension F is limited to 60-160N/mm ^2. In some preferred embodiments, in order to obtain a better implementation effect, the winding tension F can also be controlled between 80-100 N/mm ² .

Correspondingly, the coating amount of the release agent must also be considered. The more the coating amount D, the less likely it is to stick, but it should not be too much, otherwise the roll will be loosened and the finished unit will deviate during production. Therefore, the coating amount D of the release agent is limited to 10-22 g/m ² , and in some preferred embodiments, the coating amount D can also be controlled between 13-19 g/m ² .

Further, in the manufacturing method of the present invention, the winding tension F is controlled to be 80-100 N/mm ² .

Further, in the manufacturing method of the present invention, the coating amount D is controlled to be 13-19 g/m ² .

Furthermore, in the manufacturing method of the present invention, a constant tension or a varying tension is used during winding.

Further, in the manufacturing method of the present invention, when a variable tension is used for winding, the taper coefficient of the tension change is greater than 1.0 and less than or equal to 2.0.

The above-mentioned varying tension means that the tension applied to the steel coil at the beginning of coiling is F0, and the tension changes to F while the coil is coiled, F0 is greater than F, and the ratio of F0 to F is the taper coefficient.

In the above solution, when a variable tension is used for winding, the taper coefficient for controlling the tension change is greater than 1.0 and less than or equal to 2.0, which can further improve the roll shape.

Further, in the manufacturing method of the present invention, the main component of the high-temperature release agent includes MgO.

Compared with the prior art, the thin-gauge oriented silicon steel sheet and the manufacturing method thereof according to the present invention have the following advantages and beneficial effects:

(1) The thin-gauge oriented silicon steel sheet of the present invention does not require special control of the high-temperature isolating agent, and can effectively reduce the difficulty of composition and process control.

(2) The thin-gauge oriented silicon steel sheet of the present invention effectively improves the quality of the bottom layer of the substrate through reasonable chemical composition design, and reduces adhesion and deviation.

(3) The manufacturing method of the thin-gauge oriented silicon steel sheet of the present invention eliminates the defects of adhesion and deviation by appropriately matching the process conditions, especially the coiling tension and the coating amount of the release agent, and effectively ensures the obtained The quality and performance of the thin-gauge oriented silicon steel sheet greatly improves the manufacturability of the thin-gauge oriented silicon steel sheet of the present invention.

Description of the drawings

Figure 1 schematically shows the influence of coating amount and coiling tension on the manufacturability of thin-gauge oriented silicon steel sheets.

Detailed ways

Hereinafter, the thin-gauge oriented silicon steel sheet and the manufacturing method thereof of the present invention will be further explained and described in conjunction with specific embodiments and the accompanying drawings. However, the explanation and description do not improperly limit the technical solution of the present invention.

Examples 1-12 and Comparative Examples 1-10

Table 1 lists the mass percentages of various chemical elements in the thin-gauge oriented silicon steel sheets of Examples 1-12 and Comparative Examples 1-10.

Table 1. (wt%, the balance is Fe and other inevitable impurities except P and S)

The thin-gauge oriented silicon steel plates of Examples 1-12 of the present invention are all prepared by the following steps:

(1) Steelmaking: smelt and cast into slabs according to the chemical composition in Table 1;

(2) Hot rolling: heating temperature 1000～1300℃, heating time 100～500min, conventional hot rolling;

(3) Normalization: two-stage normalization: the first stage normalization temperature is 1050-1150°C, and the time is 1-30 seconds; the second stage normalization temperature is 800-1000°C, and the time is 20-100 seconds, followed by cooling and cooling Speed 10-50℃/s;

(4) Cold rolling: cold rolling to the thickness of the finished product, the cold rolling reduction rate is greater than 85%;

(5) Decarburization annealing: decarburization temperature 800-850℃, time 100-150 seconds;

(6) Coating high temperature release agent: control the coating amount D to 10-22g/m ² , and the preferred range is 13-19g/m ² ;

(7) Coiling: When coiling, control the coiling tension F to 60-160N/mm ² , the preferred range is 80-100N/mm ² , and both F and D satisfy 10×D-100<F<10 ×D+20; When coiling, use constant tension or varying tension. When coiling with varying tension, the taper coefficient of tension change is greater than 1.0 and less than or equal to 2.0;

(8) High-temperature annealing: conventional high-temperature annealing in a bell furnace or ring furnace;

(9) Hot-stretching flattening annealing: apply insulating coating on the surface of the high-temperature annealed board, and then hot-stretching flattening annealing;

(10) Finishing: the steel coil is trimmed and divided to obtain the finished product.

It should be noted that in the above step (6), the high-temperature release agent is coated, and the main component of the high-temperature release agent includes MgO.

Table 2 lists the specific process parameters of the manufacturing methods of the thin-gauge oriented silicon steel sheets of Examples 1-12 and Comparative Examples 1-10.

Table 2.

Note: It should be noted that the taper coefficient of 1.0 means constant tension.

The thin-gauge oriented silicon steel sheets of Examples 1-12 and Comparative Examples 1-10 were subjected to various performance tests, and the obtained test results are listed in Table 3. Among them, the incidence of adhesion and the incidence of deviation are based on the statistical results of the number of coils. The incidence of adhesion refers to the percentage of the number of oriented silicon steel coils that are bonded during the hot stretching and annealing process to the total number of oriented silicon steel coils. , The incidence of misalignment refers to the percentage of the number of misaligned oriented silicon steel coils in the process of hot stretching and annealing to the total number of oriented silicon steel coils. For example, taking Comparative Example 1 as an example, the total number of finished oriented silicon steel sheets of Comparative Example 1 is 38 coils. After testing, it is found that there are 10 coils of the steel plate of Comparative Example 1 that are bonded and 5 coils are deviated. Therefore, the occurrence rate of adhesion in Comparative Example 1 is 26%, and the occurrence rate of deviation is 13%.

The evaluation of manufacturability is based on the occurrence of sticking and the occurrence of deviation. When both are 0%, the manufacturability is evaluated as good, otherwise, as long as one item is not 0%, it is poor.

The measurement of iron loss P17/50 and magnetic induction B8 refer to GB/T13789.

The width of the finished product is actually measured by the tape measure after trimming by the finishing unit, and the coil weight is obtained by weighing after the output of the finishing unit.

Table 3 lists the performance test results of the thin-gauge oriented silicon steel sheets of Examples 1-12 and Comparative Examples 1-10.

table 3.

Combining Table 1 and Table 3, it can be seen that in Comparative Example 1, due to insufficient addition of elements, adhesion or deviation will occur, and the manufacturability of the thin-gauge oriented silicon steel sheet in Comparative Example 1 The manufacturability of the thin-gauge oriented silicon steel plate is poor, and the final trimming is more. The width of the finished product is only 905mm, and the coil weight is only 1.8t. Correspondingly, the addition amount of elements in Comparative Example 2-4 is greater than the design specification requirements of the present invention. Although the manufacturability of Comparative Example 2-4 is normal, it has a deteriorating effect on the magnetic properties. Generally speaking, the magnetic inductance B8 is lower than 1.88T, and the iron loss P17/50 is higher than 0.9W/Kg. The magnetic performance is not good. Although the chemical composition of the steel of Comparative Examples 5-10 meets the design requirements of the present invention, due to the presence of relevant process parameters in the process of coating high-temperature release agent and coiling, there are parameters that fail to meet the design specifications of the present invention. Although the process parameters of coating amount D and coiling tension F of 5 and Comparative Example 10 meet the requirements of the present invention, the coating amount D and coiling tension F of Comparative Example 5 and Comparative Example 10 cannot satisfy 10×D-100 <F<10×D+20, too small coiling tension or too much coating will increase the incidence of deviation, too high coiling tension or too little coating will increase the incidence of adhesion, both of which will lead to In the ratio of 5-10, the board performance deteriorates, and finally the width of the finished product is less than 1000mm, and the coil weight is less than 2t.

The thin-gauge oriented silicon steel sheets of the various embodiments of the present invention have good manufacturability, excellent electromagnetic properties, and no adhesion and deviation defects. The iron loss P17/50 of the thin-gauge oriented silicon steel plates of Examples 1-12 are all less than 0.8W/Kg, the magnetic induction B8 are all more than 1.9T, the width of the finished product is more than 1000mm, and the coil weight is more than 2t, which has good popularization and application. Value and prospects.

Figure 1 schematically shows the influence of coating amount and coiling tension on the manufacturability of thin-gauge oriented silicon steel sheets.

1, when the coating amount is less than 8g / m ^2, the manufacturing can not be obtained with good product by adjusting the winding tension, when the winding tension is less than 40Mpa, can not be obtained with good manufacturing product, It can be seen that there is an appropriate match between the amount of coating and the winding tension.

It should be noted that the prior art part of the protection scope of the present invention is not limited to the embodiments given in this application document, and all prior art that does not contradict the solution of the present invention includes but is not limited to the prior art. Patent documents, prior publications, prior publications, etc., can all be included in the protection scope of the present invention. In addition, the combination of various technical features in this case is not limited to the combination described in the claims of this case or the combination described in the specific embodiments. All technical features described in this case can be freely combined or combined in any way, unless Contradictions arise between each other.

It should also be noted that the above-listed embodiments are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and the subsequent similar changes or modifications can be directly derived from or easily associated with the disclosure of the present invention by those skilled in the art, and should fall within the protection scope of the present invention. .

Claims (11)

1. A thin-gauge oriented silicon steel sheet with excellent manufacturability, characterized in that, in addition to Fe, it also contains the following chemical elements in the following mass percentages:

   Si: 3.0～4.0%, C: 0.04～0.1%, Mn: 0.05～0.20%, S: 0.003～0.014%, Als: 0.015～0.04%, N: 0.001～0.010%, and Cr, Mo, W, V At least one of the elements, and satisfies 0.03%≤Cr+Mo+W+V≤0.2%.
2. The thin-gauge oriented silicon steel sheet according to claim 1, wherein the mass percentage of each chemical element is:

   Si: 3.0～4.0%, C: 0.04～0.1%, Mn: 0.05～0.20%, S: 0.003～0.014%, Als: 0.015～0.04%, N: 0.001～0.010%, and Cr, Mo, W, V At least one of the elements, and satisfies 0.03%≤Cr+Mo+W+V≤0.2%, and the balance is Fe and other unavoidable impurities.
3. The thin-gauge oriented silicon steel sheet according to claim 1 or 2, wherein the mass percentage content of Cr, Mo, W, and V satisfies 0.05%≤Cr+Mo+W+V≤0.1%
4. The thin-gauge oriented silicon steel sheet according to claim 1 or 2, wherein the thickness of the oriented silicon steel sheet is 0.15mm-0.23mm.
5. The thin-gauge oriented silicon steel sheet according to claim 1 or 2, wherein the oriented silicon steel sheet satisfies: iron loss P17/50<0.8W/Kg, magnetic induction B8>1.9T, and finished product width>1000mm.
6. A method for manufacturing a thin-gauge oriented silicon steel sheet according to any one of claims 1 to 5, characterized in that it comprises the steps of: steelmaking, hot rolling, normalization, cold rolling, decarburization annealing, high temperature coating Separating agent, coiling, high temperature annealing and thermal stretching and flattening annealing; among them, when coating high temperature isolating agent, control the coating amount D to 10-22g/m ² ; when coiling, control the coiling tension F to 60 -160N/mm ² , and both satisfy 10×D-100<F<10×D+20.
7. The manufacturing method according to claim 6, wherein the winding tension F is controlled to be 80-100 N/mm ² .
8. The manufacturing method according to claim 6, wherein the coating amount D is controlled to be 13-19 g/m ² .
9. 7. The manufacturing method according to claim 6, wherein a constant tension or a varying tension is used during winding.
10. 9. The manufacturing method according to claim 9, wherein when a variable tension is used for winding, the taper coefficient of the tension change is greater than 1.0 and less than or equal to 2.0.
11. 7. The manufacturing method of claim 6, wherein the main component of the high-temperature release agent includes MgO.

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