JPS62227079A - Manufacture of high silicon steel strip in continuous line - Google Patents

Abstract

PURPOSE:To manufacture the titled steel strip having high quality and high magnetic characteristics without extending a line by subjecting a steel strip to siliconization by chemical vapor deposition (CVD), diffusion treatment, cooling in a magnetic field in part of a cooling stage and coiling. CONSTITUTION:A steel strip is continuously siliconized by CVD at 1,023-1,200 deg.C in an atmosphere of a nonoxidizing gas contg. 5-35mol% SiCl4. The siliconized steel strip is subjected to diffusion treatment in an atmosphere of a nonoxidizing gas contg. no SiCl4 to diffuse Si almost uniformly into the interior of the steel strip. The steel strip is then cooled in a magnetic field by passing through a coil for applying a magnetic field fitted to a cooling furnace and the cooled steel strip is coiled. The steel strip may be cooled, coated with an insulating film, baked, cooled and coiled as required. In this case, the steel strip is cooled in a magnetic field in part of the cooling stage after the diffusion treatment and/or the cooling stage after the baking.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to continuous line chemical vapor deposition (hereinafter referred to as C
The present invention relates to a method for manufacturing high-silicon steel strips by a method (referred to as VD).

[Conventional technology] High-silicon steel sheets are used as electrical steel sheets.

It is known that the iron loss of this type of steel sheet decreases as the Si content increases, and that at 8.5% Si, the magnetostriction reaches O and the maximum magnetic permeability peaks. It is being

Conventionally, methods for manufacturing high-silicon steel sheets include the rolling method, direct casting method, and extrusion method. Of these, the rolling method can produce Si up to about 4% Si, but
If the content is high, the workability deteriorates significantly, making cold working difficult. Also, direct casting method, so-called strip casting, does not have workability problems like rolling method, but
This technology is still under development and is prone to shape defects, making it particularly difficult to manufacture high-silicon steel sheets.

On the other hand, the silicon permeation method produces high-silicon steel sheets by melting low-silicon steel, rolling it into thin sheets, and then infiltrating Si from the surface. A high-silicon steel plate can be obtained without causing any problems.

[Problems to be solved by the invention] This infiltration method was proposed by Gomoku and Dogun, and was studied in detail by Sanban and Daikyo, but all of the previously proposed methods require a long infiltration treatment time. The fundamental problem is that it is long, over 30 minutes, and cannot be applied to continuous lines. In addition, the treatment temperature is extremely low at around 1230°C, so the shape of the thin steel sheet after penetration treatment is extremely poor.In addition, because the treatment temperature is too high, the edges may melt due to overheating. Stable sheet threading cannot be expected.

The present invention has been made to improve the drawbacks of the prior art, and it is possible to stably produce high-quality high-silicon steel strips on a continuous line on a continuous line by using the silicon extrusion method. The purpose is to provide a method that can be used.

[Means for Solving the Problem 1] For this reason, the present invention uses a steel strip, SiC grade 4, and
In a non-oxidizing gas atmosphere containing ~35%, silicon was continuously treated by chemical vapor deposition at a temperature of 1023 to 1200°C, and then Si was treated in a non-oxidizing gas atmosphere containing no S:C1a. Its basic feature is that it undergoes a diffusion treatment to diffuse almost uniformly into the steel strip, and as part of the subsequent cooling process, the steel strip is cooled in a magnetic field and then rolled up.

Further, the present invention provides an insulating film coating after the above-mentioned diffusion treatment and cooling, which is then rolled up after the baking treatment, and
Another basic feature is that in-situ cooling is performed in the cooling process after diffusion treatment, the cooling process after baking treatment, or a part of both cooling processes, depending on the paint baking temperature etc. The present invention will be explained in detail below.

In the present invention, the composition of the steel strip (starting thin steel strip) serving as the base material is not particularly limited, but is preferably determined as follows in order to obtain excellent magnetic properties.

■ For 3-6.5% Si-Fe alloy c: o, ot
% or less, Si: O to 4.0%, Nn: 2% or less, and other unavoidable impurities are desirably as low as possible.

■ For Sendust alloy C: o, ot% or less, Si: 4% or less, Ai: 3~
8%, old: 4% or less, Mn: 2% or less, Cr.

It is desirable that the content of elements that increase corrosion resistance, such as Ti, be 5% or less, and that other unavoidable impurities be as low as possible.

The steel strip is not limited to one obtained by hot rolling-cold rolling, but may be one obtained by direct casting or rapid solidification.

Note that the thickness of the steel strip is reduced by CVD treatment, and therefore it is necessary to use a steel strip with a thickness equal to the thickness of the final product plus the reduced thickness.

The present invention provides such a steel strip with a silicon-etched treatment by the CVD method.
A high-silicon steel strip is obtained by performing a diffusion treatment.

FIG. 1 shows a continuous processing line for carrying out the main sprouting, in which 1 is a heating furnace, 2 is a CVD processing furnace, 3 is a diffusion processing furnace, and 4 is a cooling furnace.

The steel strip S is heated without oxidation in a heating furnace 1 to a CVD treatment temperature or around it, and then guided to a CVD treatment furnace 2, where Si
A silicon exfoliation treatment is performed by the CVD method in a non-oxidizing gas atmosphere containing CJL4. The non-oxidizing gas containing 5 iuns means a neutral or reducing gas.
As the carrier gas, Ar is used.

Among these carrier gases that can be used include I2, He, )12, C)14, etc., 82. CI4 etc.) l C
However, Ar, He, and N2 are preferable because they do not cause such problems, and from the viewpoint of preventing nitridation of the material, Ar, He, and N2 are particularly preferable. is most preferred.

What are the main reactions on the steel strip surface during CVD treatment?

5Fe+Si Cna −+Fe3 Si+2
Fe C1z ↑. Sit atoms are deposited on the steel strip surface to form a Fe3Si layer, and Fe2 atoms are deposited on the FeC
12f) and is diffused from the surface of the steel strip in a gaseous state at a temperature above the boiling point of 1023°C. Therefore, the Si atomic weight is 2B, 08B, and the Fe atomic weight is 55.
847-t', the mass of the steel strip decreases, and the plate thickness also decreases accordingly. By the way, when a 3% Si steel strip is used as the base material and an 8.5% Si steel strip is produced by CVD treatment, the mass decreases by 8.7% and the plate thickness decreases by about 7.1%.

The reason why CVD processing takes too much time in conventional methods is that
This is thought to be due to insufficient consideration being given to the CVD processing conditions.

The inventors of the present invention have investigated and found that the following factors are necessary for performing CVD processing quickly.

■ Optimization of the Si/C concentration in the atmospheric gas.

■ Optimization of processing temperature.

■ Diffusion of Si C 4 onto the steel strip surface and Fe C 2
promotion of dissipation from the steel strip surface.

Therefore, in the present invention, the Si concentration in the atmospheric gas and the processing temperature in the CVD processing are specified.

First, the degree of Si C14a in the non-oxidizing gas atmosphere during CVD treatment is defined as 5 to 35% in terms of lon fraction,
The steel strip is continuously subjected to CVD treatment in such an open atmosphere.

S expects that SiC structure 4 in the atmosphere is less than 5%
The i-enriching effect cannot be obtained, and for example, if the Si of the steel strip is 1.
The treatment takes too much time, such as requiring 5 minutes or more to achieve 0% enrichment, making it difficult to implement a continuous process.

On the other hand, even if 5iCu4 is contained in an amount exceeding 35%, the reaction at the interface becomes rate-limiting, and no further Si enrichment effect can be expected.

In addition, in CVD processing, the higher the concentration of Si C1 However, when the concentration is below 35%,
Even if voids are generated, they can be almost completely eliminated by a diffusion process performed subsequent to the CVD process. In other words, when the 5iCJla concentration exceeds 35%, voids are significantly generated and remain even after diffusion treatment.
Fig. 11 shows a cross section of the steel strip immediately after CVD treatment in an atmosphere of 5i (dL420%), and voids are seen in the vapor deposited layer. Fig. 12 shows this steel strip at 1200℃ x 20 w.
It shows a cross section after diffusion treatment of in, and CVD
Immediately after treatment, the voids almost completely disappeared. On the other hand, FIG. 13 shows a cross section of a steel strip that was subjected to CVD treatment with 440% SiC content and then diffusion treatment, and it can be seen that voids remain in a layered manner.

The CVD treatment temperature is in the range of 1023 to 1200°C.

Since the CVD treatment reaction is a reaction on the steel strip surface, the treatment temperature is strictly the steel strip surface temperature.

The boiling point of FeCl2, which is a reaction product from the CVD process, is 1023°C, and below this temperature it will adhere to FeCl2f in a liquid state and inhibit the vapor deposition reaction.

According to the results of basic experiments conducted by the present inventors, this FeC1
The enrichment rate of Si per unit time differs markedly at the boiling point of y, and the 7X deposition rate is low below 1023°C, making it difficult to apply to a continuous process.

Therefore, the lower limit of the processing temperature is set to 1023°C.

On the other hand, the reason why the upper limit is specified as 1200°C is as follows.* The melting point of Fe3S+ is
As is clear from the phase diagram, the temperature is 1250°C, but according to experiments conducted by the inventors, even when the steel strip surface is processed at about 1230°C, which is lower than 1250°C, the steel strip surface partially melts, and the steel strip edge Parts melt due to overheating.

The reason why the steel strip melts even below 1250° C. is presumed to be because Si is deposited on the surface of the steel strip at a Si concentration of 14.5% or more equivalent to Fe3Si. On the other hand, if the treatment temperature is 1200°C or lower, no melting will be observed on the surface of the steel strip, and overheating of the edges can be prevented by setting the average temperature at the center of the steel strip to 1200°C.
The CVD treatment temperature is specified as 1023° C. to 1200”c!, because it has been experimentally confirmed that the temperature can be kept at about 1023° C. and only a small amount of dissolution is required.

The steel strip S subjected to the CVD treatment as described above is subsequently led to a diffusion furnace 3 and subjected to a diffusion treatment in a non-oxidizing gas atmosphere that does not contain S:C1a. In other words, immediately after the /D treatment, the Si concentration is high near the steel strip surface, and the Si concentration in the center remains the same as the base material.
It is necessary to set the Si concentration.

This diffusion treatment must be performed in a non-oxidizing atmosphere in order not to oxidize the surface of the steel strip, and the higher the temperature, the shorter the treatment time.

This diffusion treatment may be carried out at a constant temperature, but as can be seen from the Fe-9i phase diagram in Figure 3, as the diffusion progresses, the Si concentration in the surface layer of the steel strip decreases and its melting point increases. For example, 8.5% Si diffusion can be promoted by gradually increasing the temperature (for example, increasing the temperature in multiple steps) to an extent that does not melt the steel strip.
In the case of steel, it is possible to raise the temperature to 1400° C. even taking into account overheating of the edges.

After such a diffusion treatment, the steel strip S is cooled in a cooling furnace 4,
After that, it is rolled up, but in the present invention, the -
The steel strip S is cooled in a magnetic field in the ° section.

It is known that the magnetic properties of a silicon steel sheet are significantly improved by cooling it in a magnetic field. In the present invention, as part of the cooling process, the steel strip S is passed through a magnetic field and cooled in a magnetic field. do.

The steel strip S is influenced by magnetism at temperatures below the Curie point, and cooling in a magnetic field exhibits a substantial effect at temperatures below the Curie point. In particular, when cooling in a magnetic field, the temperature of the steel strip is A
The magnetic properties are significantly improved by carrying out the process when passing through the second transformation point. Figure 14 shows the relationship between the plate temperature of a silicon steel sheet and the cooling effect in a magnetic field.1 For example, in the case of an 8.5 wt% Si steel strip, temperature t1 is the Curie point, temperature t2 is the A2 transformation point, and the temperature t2 is the A2 transformation point. Cooling starts from a temperature Ts (for example, 750° C.) higher than the normal temperature t1, passes through a temperature t2, and ends at a temperature TF.

15 to 17 show an example of the configuration of magnetic field cooling equipment, in which a magnetic field applying coil 8 provided in a cooling furnace is constructed from a hollow copper tube 9, and a cooling medium 1 is placed inside the copper tube 9.
By passing 0, a magnetic field is applied to the steel strip S passing through the magnetic field applying coil 8, and radiative cooling is performed from the inner surface of the coil. Note that an insulating film 11 (Si02, etc.) is formed on the outer surface of the copper tube 9.

Water can be used as the cooling medium, but if there is an electrical problem, for example, a highly insulating fluorine-based inert liquid can also be used.

FIG. 18 shows another configuration example, in which a nozzle 12 for supplying cooling gas into the coil is provided at the steel strip exit position of the magnetic field applying coil 8, and further, the upper and lower parts of the magnetic field applying coil 8 are provided. Cooling gas introduction duct 15 and hood 14
The cooling gas is supplied to the outside of the coil by a fan 13.

FIG. 19 shows that in the installation method shown in FIGS. 15 to 17, the spacing between the magnetic field applying coils 8 (the spacing between the steel pipes) is made denser in sequence or in stages from the inlet side to the outlet side of the steel strip S. By doing so, it is possible to achieve uniform cooling and improve the magnetic field cooling effect. In other words, the denser the coil is, the faster the cooling rate of the steel strip becomes. Therefore, by passing the steel strip S through such a coil, the steel strip S is kept at a constant speed as shown in the figure. This allows for uniform cooling in the thickness direction, resulting in smooth transformation and excellent magnetic properties. In addition, the denser the coil, the stronger the magnetic field can be applied to the steel strip, but as mentioned above, the steel strip is strongly influenced by the magnetic field in the low temperature range below the Curie point, especially at the A2 transformation point. Therefore, by making the coil denser on the low temperature side and applying a strong magnetic field at least when passing the A2 transformation point, a large cooling effect in the magnetic field can be obtained.

In some cases, contrary to the above, it is also possible to adopt a structure in which the intervals between the magnetic field applying coils 8 are made closer on the inlet side of the steel strip S, and are gradually arranged in lines toward the outlet side. With such a structure, rapid cooling of the steel strip is possible, and by keeping the coil relatively dense at least until the steel strip passes through the A2 transformation point, a large cooling effect in the magnetic field can be ensured. .

The steel strip S is cooled as described above and wound into a coil. In this case, the Si content is generally high (for example, 4.0
% or more), relatively thick steel strips need to be rolled up warm.

In order to increase the CVD processing speed to the point where continuous processing of the steel strip becomes possible, it is necessary to
14 It is necessary to optimize the concentration and treatment temperature, but in addition to this, it is necessary to
C by promoting the dissipation from the steel strip surface.
It becomes possible to further increase the VD processing speed.

Conventionally, it has been thought that if the reactive gas is allowed to flow greatly during CVD processing, voids will occur in the vapor deposited layer and the purity of the vapor deposited layer will also decrease.Therefore, the idea has been that the gas flow should be kept to the minimum necessary. . However, in the research conducted by the present inventors, due to the gas flow being suppressed in this way, the diffusion movement of the reaction gas to the base material interface and the separation of reaction by-products from the interface surface layer do not occur smoothly. It has been found that the treatment takes a long time, and furthermore, because the gas flow is suppressed, the concentration of the reactant gas in the CVD treatment furnace is distributed, resulting in non-uniformity in the thickness of the deposited film.

Based on these facts, we conducted further studies and found that 5iC1a could be applied to the surface of the steel strip by blowing atmospheric gas onto the treated material using a blowing nozzle in the CVD processing furnace, or by forcing the atmosphere to circulate using a fan, etc. It was found that the diffusion and reaction product, FeCl2, from the surface of the steel strip was significantly promoted, and CVD processing could be performed at a high deposition rate while suppressing non-uniformity of the deposited film.

A method in which atmospheric gas is sprayed onto the surface of the steel strip using a spray nozzle is particularly effective for improving CVD processability.

Figure 4 shows this nozzle spraying method. This shows the implementation status, and a spray nozzle 5 is installed in the CVD treatment furnace 2 facing the steel strip S.
is placed, and an atmospheric gas containing 5ills is blown onto the surface of the steel strip. Figures 5 (a) and (b) show the spraying conditions by the spray nozzle 5, in which the spraying is performed at right angles to the steel strip surface as shown in (a) or from an oblique direction as shown in (b). Can be attached.

The Si enrichment rate per unit time due to such nozzle spray increases in proportion to the increase in the velocity of the gas impinging on the steel strip surface. The above Si-enriching effect cannot be expected; generally, a sufficient effect can be obtained with a flow rate of 5NW7 sec or less.

Further, in the present invention, after the above-mentioned diffusion treatment and cooling, the steel strip can be continuously coated with an insulating film, and can be rolled up after the baking treatment. FIG. 2 shows a continuous processing line for this purpose, where 6 is a coating device and 7 is a baking furnace.

Electrical steel sheets are usually used in a laminated state, and in this case, each of the laminated steel sheets needs to be insulated. For this reason, electrical steel sheets are coated with an insulating film.

Steel strips with a Si content of 4.0% or more are brittle materials at room temperature and rarely undergo plastic deformation, so if the insulation film coating is done on a separate line from the CVD treatment line, There is a risk that the steel strip will break during unwinding and unwinding of the coil. Therefore, in the present invention, after the diffusion treatment and cooling, an insulating paint is applied to the steel strip S in a coating device 6, and then a baking treatment is performed in a paint baking furnace 7.

As the insulating paint, appropriate inorganic or organic paints can be used. As an inorganic paint.

For example, magnesium phosphate, chromic anhydride, silica sol, etc. are used, and as the organic paint, Plasti-2 resin etc. are used. The paint is applied to the steel strip S using a roll coater method, one-way spray method, etc., and in the case of inorganic paint, approximately 80%
Baking treatment is carried out at about 0°C, and in the case of organic paints, at about 200 to 300°C.

When performing the above-mentioned insulating film coating-baking treatment, the timing of cooling in a magnetic field is an issue. If high-temperature baking is performed as in ', even if cooling in a magnetic field is performed in the cooling after the previous step of CVD treatment and diffusion treatment, the effect will disappear.

Therefore, in a process involving insulating film coating and baking, cooling in a magnetic field can be performed in the cooling process after the diffusion process or in the cooling process after the baking process, depending on the coating baking temperature and the like. The reheating temperature at which the effect of cooling in a magnetic field disappears is said to be around 850°C, so the baking treatment temperature is 850°C.
It is preferable to perform cooling in a magnetic field in the cooling process after the baking process when the temperature is 5θ°C or higher, and in the cooling process after the CVD process-diffusion process when the baking process temperature is less than 850°C.

Generally, when baking inorganic paint, a steel strip with a
Therefore, in this case, there is no point in cooling in a magnetic field before coating, and it is preferable to cool in a magnetic field during the cooling process after baking. A baking temperature of about 300° C. is sufficient, and in this case, cooling in a magnetic field can be performed in the cooling process after the CVD treatment and the diffusion treatment.

Note that the cooling in a magnetic field can be performed both in the cooling process after the CVD process and the diffusion process and in the cooling process after the coating and baking process, depending on the case.

Non-oxidation heating is performed in the heating furnace I, and for this reason, a heating method such as electric indirect heating, induction heating, radiant tube indirect heating, direct fire reduction heating, etc. may be used alone or in an appropriate combination. Note that when using an indirect heating method, a pretreatment such as electric washing is performed prior to heating. For example, the following heating method including pretreatment can be adopted.

■ Pretreatment - [Preheating] - Electrical contact,! 8 (or induction heating) ■ Pretreatment - [Preheating] - Radiant tube heating - Electrical indirect heating (or induction heating) ■ [Preheating] - Direct flame reduction heating - Electrical indirect heating (or induction heating) ■ Pretreatment - [Preheating] ] - Radiant tube indirect heating (
Ceramic radiant tube system) % formula % Furthermore, there is no particular limitation on the cooling method in the cooling furnace 4, and various cooling methods such as gas jet cooling, mist cooling, and radiation cooling can be employed alone or in combination.

As mentioned above, the present invention is suitable for manufacturing steel strips with extremely high silicon content, such as 8.5% S+ steel strips. There is an advantage that high-silicon steel strips with a Si content of about 2 to 4%, which had a poor yield due to a large amount of Si, can be easily manufactured.

[Example] O Example-1 Using a small CVD processing furnace-diffusion processing furnace, the influence of 5iC1sfa degrees and CVD processing temperature on CVD processing performance was investigated. The results are shown in FIGS. 6 and 7.

In the figure, A is the atmosphere method, that is, CVD treatment without nozzle spraying, and B is the nozzle spraying method, that is, as shown in FIG.
It shows the case where CVD treatment is performed while spraying at a flow rate of S. Note that the Si enrichment ratio indicates the increase in Si after the CVD treatment-diffusion treatment with respect to the initial Si concentration of the base material.

ht: If SiCjLm concentration is 5% or more, cvn
A large Si-enriching effect is obtained at a treatment temperature of 1023° C. or higher. Even under the same conditions, the method of spraying atmospheric gas with a spray nozzle has a much superior Si enrichment effect (c
vn processability) was obtained.

Figure 8 shows the deposition time and Si concentration in the steel strip (
(Si concentration after diffusion treatment).

Si: 3%, plate thickness 0.5i+ layer tjI4 band 5iC
This is an investigation of the case where CVD treatment was performed at a 1a concentration of 21% and a treatment temperature of 1150°C. In addition, in the nozzle spray method.

0°2N from the perpendicular direction to the steel strip using a slit nozzle
Atmospheric gas was blown at a flow rate of m/see. As can be seen from the figure, it took 7 minutes in atmosphere method A to obtain 6.5% Si steel, whereas it took 1.5 minutes in nozzle spray method B.

Figure 9 shows the collision gas flow velocity and S of the steel strip in the nozzle spraying method.
This shows the relationship with the i enrichment ratio (the ratio after diffusion treatment), and the Si enrichment ratio of the steel strip increases in proportion to the collision gas flow rate up to a predetermined level.

0 Example-2 A plate with a thickness of 0.35 mm and a plate width of 9 was manufactured using the continuous process shown in Figure 1.
A steel strip containing 8.5% Si was manufactured using a steel strip having a thickness of 00 mm and containing 3.5% Si as a base material at a line speed of 25 pm.

In addition, in the cooling furnace, cooling is carried out in a magnetic field, and in the CVD processing furnace, using a spray nozzle method, an atmospheric gas of 4E 20sa 1% with Ar as a carrier gas is applied to the steel plate at a flow rate of 0.3N layers/sec. I sprayed it with

FIG. 10 shows the thermal cycle in this case, and in this example, two-stage heating from 1200° C. to 1320° C. was performed during the diffusion treatment. As a result, V'i+o/lo: 0.
High quality 6.5% with extremely low core loss of 55W/Kg
S: W4 belt could be manufactured.

Example 3 A steel strip after CVD treatment and diffusion treatment was cooled in a magnetic field during the cooling process, and its magnetic properties were investigated. Figure 20 shows the results. In the figure, ■ indicates that cooling is not applied in a magnetic field, ■ indicates that a magnetic field of 300 e is applied using a coil wound at an even pitch, and ■ indicates that the same result is obtained using the apparatus shown in Fig. 19. As shown in the figure, the cases in which the magnetic field is strengthened step by step and cooled in the magnetic field are shown, and in particular, cooling in the magnetic field is performed using the method shown in Figure 19, in which a strong magnetic field is applied before and after passing the A2 transformation point. As a result, it can be seen that extremely excellent magnetic properties are obtained.

[Effects of the Invention] According to the present invention described above, CVD treatment can be performed in a short time on a continuous line, and since the CVD treatment is performed at a temperature of 1200°C or less, there are no problems such as poor shape of the steel strip or edge melting. It is possible to obtain a steel plate that does not cause any problems and has excellent magnetic properties.
High-quality, high-magnetic, high-silicon steel sheets can be produced at a high rate without increasing the length of the line.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams showing continuous processing lines for carrying out the method of the present invention, respectively. Figure 3 shows Fe-3
It is an i-system state diagram. Figures 4 and 5 (a) and (b) show the CVD processing situation using the nozzle spraying method. FIG. FIG. 6 shows the relationship between the SiC concentration in the gas (4c degree) and the Si enrichment ratio in the steel strip in the CVD treatment, and FIG. 7 shows the relationship between the CVD treatment temperature and the Si enrichment ratio in the steel strip. FIG. 8 shows a comparison of the relationship between the Si vaporization time and the degree of 5iIH in the steel strip in the present invention using the atmosphere method and the nozzle spraying method. FIG. 9 shows the relationship between the impinging gas wave velocity of the atmospheric gas against the steel strip and the Si enrichment ratio of the steel strip in the CVD treatment using the nozzle spraying method. FIG. 1O shows a processing heat cycle in an example of the present invention. Figures 11 to 13 are li3 microscopic enlarged photographs showing the metallographic structures of cross sections of steel strips of the present invention material and comparative material, and Figure 11 is a Si
C View 4: Structure immediately after CVD treatment in a 20% atmosphere,
Figure 12 shows the structure after diffusion heat treatment of the m4i't, and Figure 13 shows the structure after CVD treatment with SiC4:40%.
The tissue after being subjected to diffusion treatment is shown. FIG. 14 shows the relationship between the temperature of a silicon steel plate and the cooling effect in a magnetic field. Figures 15 to 17 show an example of the configuration of magnetic field cooling equipment. Figure 15 is a perspective view, Figure 1B is a cross-sectional view of the coil, and Figure 17 is a cross-sectional view of the steel pipe that constitutes the coil. be. FIG. 18 is an explanatory diagram showing another example of the configuration of the cooling equipment in a magnetic field. FIG. 18 is an explanatory diagram showing a preferred equipment for cooling in a magnetic field and a cooling method in a magnetic field using the equipment. Second
Figure 0 shows the magnetic properties when cooled in a magnetic field compared to when cooled simply. In the figure, 1 is a heating furnace, and 2 is a CVD processing furnace. 3 is a diffusion treatment furnace, 4 is a cooling furnace, 6 is a coating equipment,
7 is a baking furnace, and S is a steel strip. - Miserable temperature (0c) s; l Ipg11 min (wt'10)Si
＄I Otsu1”Je (Wiolo)Si ”l
Ushi @ 11 A, (olo) leak 10 figure negative"11f3.'J Jin・12 command xl (1) O α; 13 坏 figure 15 figure 16 figure 17 figure 18 figure OOOOOOQ 0000 ooooooooooo
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Claims (2)

[Claims] (1) Steel strip with SiCl_4 in a mol fraction of 5 to 35%
In a non-oxidizing gas atmosphere containing Si, silicon is continuously treated by chemical vapor deposition at a temperature of 1023 to 1200°C, and then Si is deposited inside the steel strip in a non-oxidizing gas atmosphere containing no SiCl_4. A diffusion process is applied to disperse the material almost uniformly,
A method for manufacturing a high-silicon steel strip in a continuous line, characterized in that in a part of the subsequent cooling process, the steel strip is cooled in a magnetic field and then rolled up. (2) Steel strip with SiCl_4 at a mol fraction of 5 to 35%
In a non-oxidizing gas atmosphere containing Si, silicon is continuously treated by chemical vapor deposition at a temperature of 1023 to 1200°C, and then Si is deposited inside the steel strip in a non-oxidizing gas atmosphere containing no SiCl_4. A diffusion process is applied to disperse the material almost uniformly,
After cooling, an insulating film coating is applied and baked, and after cooling, it is rolled up, and the cooling process after the diffusion treatment and/or
Alternatively, a method for producing a high-silicon steel strip in a continuous line, characterized in that the steel strip is cooled in a magnetic field during part of the cooling process after baking treatment.