JPS62227036A - Manufacture of high silicon steel strip in continuous line - Google Patents

Abstract

PURPOSE:To manufacture high silicon steel sheet having uniform sheet thickness and superior toughness, magnetic characteristic, by permeating Si to silicon steel sheet by chemical vapor deposition method due to SiCl4, to ununiformly diffuse Si in thickness direction, then cooling in magnetic field, working by warm rolling and forming insulating film. CONSTITUTION:Silicon steel sheet contg. relatively low Si of about 3% is manufactured by hot and cold rollings, the sheet is heated to 1,023-1,200 deg.C in nonoxidizing gas atmosphere such as Ar, N2 contg. 5-35% SiCl4 in mol fraction to form Fe3Si layer contg. 14.5% Si on steel sheet surface. This is heated in nonoxidizing gas atmosphere to diffuse Si while gradually decreasing it to the center part so that 6.5% and 3% Si are attained at the surface and center part respectively. Insulating film is baked on the surface of silicon steel sheet to finishing, or the sheet is warm rolled in the course of or before or after cooling process after Si diffusion treatment, cooled in magnetic field after insulating film formation, or cooled in magnetic field after Si diffusion treatment, on the course of or before or after it, plastically worked by warm rolling, then insulating film is baked and cooled again in magnetic field.

Description

[Detailed description of the invention] [Industrial use! l') ] The present invention is a continuous line chemical vapor deposition (hereinafter referred to as C
The present invention relates to a method for manufacturing high silicon steel strip using the VD method.

[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 at 6.5% Si, the magnetostriction reaches O and the maximum magnetic permeability peaks. It is being

Conventionally, there are rolling methods, direct casting methods, and silicon extrusion methods for producing high-silicon steel sheets. Among these, the rolling method can produce up to about 4% Si content, but
When the content of m is high, the workability deteriorates significantly and cold working is difficult. In addition, although the direct casting method, so-called S1~RIP V-sting, does not have workability problems like the rolling method, it is still a technology in its infancy and is prone to shape defects, making it particularly difficult to manufacture high-silicon steel sheets. It is.

On the other hand, in the silicon-extrusion method, low-silicon steel is melted and rolled to achieve a
After forming a plate, a high silicon steel plate is produced by infiltrating Si@ from the surface. According to this method, a high silicon steel plate can be obtained without causing problems with workability or poor shape.

[Problems to be solved by the invention] This method 4. (Proposed by Goyumi and Sumibe, and examined in detail by Mitani and Ohmagari et al., all of the previously proposed methods require long penetration times of 30 minutes or more, and CVD treatment !I!The diffusion heat treatment that will be performed later also
The fundamental problem is that it takes a relatively long time to uniformly diffuse the deposited Si into the base material, and in fact cannot be applied to a continuous line.

CVD place 1 again! l! Humidity is extremely high at around 1,230°C, so the shape of the thin steel sheet after penetration treatment is extremely poor.In addition, the treatment temperature is too high, so the edges may overheat and melt. Stable plate threading cannot be expected.

In addition, in the silicon extrusion method, the R of the steel plate surface is rec, due to the vapor deposition reaction.
o The result is a failure in the form of 2nd grade, and the thickness of the J plate is reduced due to this. However, in this type of treatment, the deposition (film thickness) tends to become non-uniform due to non-uniformity in the atmospheric gas 12 degree distribution, etc.
As a result, there is a problem that the thickness of the plate tends to be uneven in the width direction and the length direction due to variations in the way the plate thickness is reduced.

In addition, high-silicon steel sheets with a Si content of 4.0% or more are brittle, and the treatment LL1! There is also the problem that the steel plate is easily broken when it is wound into a coil.

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

Therefore, the basic features of the present invention are as follows.

(1) tt4 band, SiCl4 to mo! In a non-oxidizing gas atmosphere containing 5 to 35% J fraction, continuous silica treatment is carried out at a humidity of 1023 to 1200°C by chemical vapor deposition, and then 5iCJ) 4-free non-oxidizing When performing a diffusion treatment to diffuse Si into the steel strip in a gas atmosphere, the diffusion treatment is discontinued while the surface layer Si concentration is higher than the Si concentration at the center of the steel strip in the thickness direction,
In the subsequent cooling process, the steel strip is cooled in a magnetic field, and at R4 or after or during the cooling in the magnetic field, the steel strip is rolled in a warm state. A method for producing a high-silicon steel strip on a continuous line, characterized by plastic working.

(2) Steel strip with 5iCJl 4 at moj fraction of 5 to 35
% in a non-oxidizing gas atmosphere containing SiCl) 4, continuous silicon leaching treatment was performed at a temperature of 1023 to 1200°C by chemical vapor deposition method, and then in a non-oxidizing gas atmosphere containing no r:SiCl)4. When carrying out the diffusion treatment to diffuse Si into the steel strip, the diffusion treatment is discontinued while the surface layer Si concentration is higher than the Sin degree at the center in the thickness direction of the steel strip.
Taki 1ffi obtained a steel strip that is uneven in the thickness direction, followed by cold r
In the JI process, the steel strip is subjected to a magnetic field of 7J1,
In the middle of the magnetic field, before or after 1, or in the middle of the turn,
The steel strip is plastically worked by rolling in a warm state, and finally cooled by IJ+.
A method for producing a high silicon steel strip in a continuous line, which is then subjected to insulation film coating and baking treatment.

(3) Steel strip with 5iCfJ4 at an moj fraction of 5 to 35%
In a non-oxidizing gas atmosphere containing SiCl4, the silicon is continuously treated by chemical vapor deposition at a temperature of 1023-1200°C, and then S in a non-oxidizing gas atmosphere containing no SiCl4.
When conducting the diffusion treatment to diffuse i into the steel strip, the diffusion treatment is terminated while the surface layer Si concentration is higher than the Si5 degree at the center of the steel strip in the thickness direction, so that the Si concentration is non-uniform in the thickness direction. During the cooling process or after cold fJI, the steel strip is rolled in a warm state for plasticity:
A method for manufacturing a high silicon steel strip on a continuous line J3, characterized in that after final cooling, an insulating film coating and baking treatment are performed, and a magnetic field is applied halfway during the subsequent cooling process.

(4) Steel strip, SiCl) 4 to 5 at lloJl fraction
~35%/v of silicon in a non-oxidizing gas atmosphere by chemical vapor deposition method at a temperature of 1023-1200°C, and then Si in a non-oxidizing gas atmosphere containing no SiCl4. When performing a diffusion treatment to diffuse Si into the steel strip, the diffusion treatment is terminated while the surface layer Si concentration is higher than the Si concentration at the center of the steel strip in the thickness direction.
During the cooling process of a steel strip whose concentration is independent in the thickness direction, the steel strip is cooled midway in a vii field, and before, after, or during the cooling in the magnetic field, the steel strip is subjected to plastic working by rolling in a warm state. A method for manufacturing a high silicon steel strip in a continuous line, characterized in that after final cooling, coating with an insulating film and baking treatment, followed by cooling in a magnetic field in the cooling process.

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 R1 material is not particularly limited, but is preferably determined as shown below in order to obtain excellent magnetic properties.

■ 3-6.5% 5i-re gold alloy C: 0.01%
Hereinafter, it is preferable that S be 0 to 4.0%, Mn be 2% or less, and that unavoidable impurities be as low as possible.

■ For Sendust alloy C: 0.01% or less, Si: 4% or less, A, O: 3-8
%, N1: 4% or less, Mn: 2% or less, elements that increase corrosion resistance such as Or, -ji, etc., 5% or less, and other unavoidable impurities as low as possible.

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

<'t J3, As mentioned above, the thickness of the steel strip is reduced by CVD treatment, and therefore, it is necessary to use a steel strip with a thickness that is equal to the thickness of the final product plus the reduced thickness.

The present invention provides a high-silicon steel strip by subjecting such a steel strip to exfoliation treatment and widening of the surface area by the CV I) method.

FIG. 1 shows a continuous processing line for carrying out the method of the present invention, where 1 is a heating furnace, 2 is a CVD processing furnace, 23 is a diffusion processing furnace, and 4 is a cold moon 1 furnace.

The steel strip S is heated without oxidation in the heating furnace 1 to the near south of the CVD treatment, and then led to the CVD treatment furnace 2, where it is heated with 5iC
J) A silicon exfoliation treatment is performed by the CVD method in a non-oxidizing gas atmosphere containing 4. , a non-oxidizing gas containing SiCl4 (meaning a neutral or reducing gas, SiCl4
Ar is used as the carrier gas.

N2,. 1-1e, th, Cl-14Qf
Use f to categorize. Among these carrier gases, if the exhaust gas treatment ↑I[ is chemically converted, t12, CH
4th place generates Hol! There is a drawback that such processing is necessary, and Δr, H(!, N
2 is preferable, and from the viewpoint of preventing nitridation of the material r1, among these, Ar and l-1e are most preferable.

The main reaction on the steel strip surface during CVD treatment is 5 rO-1
-5iCJl 4-* Fc3 Si 4-2rcCf
J2↑. , Si1 atoms are deposited on the steel strip surface to form Fc3
A Si layer is formed, and ``e2 atoms are FcC, lI 2 and <
It is emitted from the surface of the steel strip in the form of a gas at a humidity higher than the boiling point of FeCj 2, 1023°C. Therefore S
i atom 11 is 28.086, [C atomic weight is 55.847
Therefore, the mass of the steel strip decreases, and the weight of the plate also decreases accordingly. By the way, when a 16.5% S steel strip is manufactured by CVD using a 3% Si steel strip as a base material, the mass decreases by 8.7% and the plate thickness decreases by about 1.1%.

The reason why CVD processing takes too much time in conventional methods is that
This may be due to the fact that no thorough consideration was 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 SiCρ4 concentration in atmospheric gas.

■ Optimization of processing temperature.

■SiCl! 4 to the steel strip surface and rec, l
) Promotion of dissipation from the steel strip surface in step 2.

For this reason, in the present invention, the degree of Si depth and treatment in the atmospheric gas during the CVD treatment are determined. l! It regulates the temperature.

First, 5i in a non-oxidizing gas atmosphere during CVD treatment.
The CJl4 vagueness is defined as 5 to 35% in terms of ll101 fraction, and the steel strip is continuously subjected to CVD treatment in such an atmosphere.

If Si (,114) in the atmosphere is less than 5%, the expected Si enrichment effect cannot be obtained;
．． The treatment takes too much time, such as requiring more than 5 minutes to achieve 0% enrichment, making it difficult to implement a continuous process.

On the other hand, even if 5iCfJ4 is contained in an amount exceeding 35%, the reaction at the interface is extremely rapid, and no further Si enrichment effect can be expected.

Furthermore, in the C V l) process, the higher the degree of 5iC4n fJ, the more likely it is that large voids, so-called Kirkendahl voids, will be generated. This void G, LSiCJI 49 degrees, is hardly seen until it is polished by about 15%, but it starts to form when it exceeds 15%. However, in the case of C having a SiCl n Si content of 35% or less, even if voids are generated, they can be almost completely eliminated by a diffusion process performed subsequent to the CVD process. The time required for voids to disappear strongly depends on the temperature of the diffusion process, and it is possible to eliminate voids in a short time by increasing the process temperature according to the decrease in surface layer Si depth after the start of diffusion. can. However, SiC
When ρ4i2 degrees exceeds 35%, the diameter of the generated void becomes large, and adjacent voids coalesce to become even larger, and the void remains even after long-time diffusion soaking treatment. On the other hand, SiCρ4i11 degrees is 35
% or less, H'i 8AIi can be achieved by diffusion processing because the void will not be too large.

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

'CV D treatment 1ψ reaction is a reaction on the surface of the steel strip, so here] I\! Strictly speaking, the degree of thirst is the surface temperature of the steel strip.

Fe(1) 2 which is a reaction product from CV I) treatment
The boiling point of FeCn is around 1023℃, and FeCn
2 is not dissipated from the steel strip surface in a gaseous state, but adheres to the steel strip surface in a liquid state and inhibits the vapor deposition reaction. As a result of basic experiments conducted by the inventors, [,1, this lec, Q2
The enrichment rate of Si per unit time differs markedly at the boiling point of , and at temperatures below 1023°C, the 'a deposition rate is low, 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 Fe3Si is 1250°C, as is clear from the Fc-3i phase diagram shown in Fig. 4, but according to experiments by the inventors, even when treated at about 1230°C, which is lower than 1250°C, the melting point of Fe3Si is 1250°C. The surface of the band is partially dissolved, and
The edge of the steel strip melts due to overheating.

The reason why the steel strip melts even at 1250° C. or lower is presumed to be because Si is deposited on the surface of the steel strip at a Si concentration of 14.5% or higher, which corresponds to re3 si. On the other hand, if the processing temperature is below 1200°C, no melting will be observed on the surface of the steel strip, and overheating of the edges will be reduced to 1220°C by setting the average temperature at the center of the steel strip to 1200°C.
It was experimentally confirmed that it was possible to suppress the amount of dissolution to a small extent, and that only a slight dissolution was required. For the above reasons, the CVD treatment temperature is defined as 1023°C to 1200°C.

The steel strip S subjected to the CVD treatment as described above is then led to a diffusion furnace 3 and subjected to a diffusion treatment in a non-oxidizing gas atmosphere containing no SiCgl. In other words, immediately after CVD treatment, the Si concentration near the surface of the steel strip is extremely high compared to the center, and when the steel strip is soaked, the overheated Si on the surface is diffused into the inside of the steel strip. Process. However, in the present invention, this diffusion heat treatment does not often disperse Si uniformly within the steel strip, and even though the surface layer 5ii11 degree is higher than the Si concentration at the center in the thickness direction of the steel strip, the diffusion heat treatment The steel strip is cut off and the Si concentration is non-uniform in the thickness direction.

From the viewpoint of shortening the diffusion processing time, the present inventors have developed a CVD process! l! As a result of examining the relationship between the 5ic degree distribution and magnetic properties of steel materials, we found that the magnetic properties of high-silicon steel materials are largely controlled by the grain size and Si concentration in the surface layer of the steel material. It has been found that by adjusting i ilJ Iff, it is possible to obtain magnetic properties of 1-min without making the Si concentration uniform in the thickness direction. It was also found that this tendency is particularly remarkable at high frequencies...feeling↑1.

For this reason, in the present invention, the diffusion treatment following the CVD treatment is performed while the surface layer Si concentration is higher than the Si concentration at the center in the direction of the steel strip. This is to obtain a steel strip.

According to this method, ta can be reduced by short-time diffusion heat treatment.
Ki 1! It is possible to obtain a steel strip with sufficient properties.

In addition, the steel strip obtained in this way maintains a low Si concentration in the center of the thickness, ensuring toughness and
Its breakage can be appropriately prevented.

Figure 5 shows the change in the Si degree distribution in the V direction of the steel strip plate according to the method of the present invention, and shows the case where a steel strip containing 3% Si is used as the base material and this is subjected to CVD treatment and diffusion treatment. There is. (8) shows the state of CvD treatment 100(ν), and the surface of the steel strip has 31
In the present invention, this steel strip is subjected to diffusion heat treatment to the state (B), and the Si concentration is non-uniform in the thickness direction.
Obtain a steel strip. In the example of adding to (B), the Si concentration in the surface layer is 6
, 5%, and the central part of the plate F is maintained at 3%, which is the Si concentration of the Ill material.

The steel strip obtained in this way has excellent magnetic properties, especially high-frequency magnetic properties, by selecting the diffusion heat treatment temperature and treatment time and adjusting the surface layer to a grain size and Si concentration equivalent to )δ. be able to.

This diffusion treatment must be carried out in a non-oxidizing atmosphere in order not to oxidize the surface of the steel strip, and the higher the temperature it is carried out, the shorter the treatment time and the more widespread it is.

The diffusion treatment may be carried out at a constant temperature, but as shown in FIG.
As can be seen from the -3i phase diagram, as the diffusion progresses, the Si il'J degree of the surface layer of the steel strip decreases and its melting point increases, so as the diffusion progresses, the steel strip gradually melts to the extent that it does not melt. By increasing the temperature (for example, increasing the temperature in multiple steps), the process can be carried out in a short time.

After this J: una diffusion treatment, the steel strip S is cooled in a cooling furnace 4 and then wound up. In the present invention, in this cooling process, the steel strip is
After halfway bending in the field or midway through the magnetic field 1J] or during cooling in the magnetic field, the steel strip S is plastically loaded by rolling in a 361-degree state.

It is known that the magnetic retention of No. 1 wood steel can be significantly improved by performing mid-IJI in a magnetic field.In the present invention, N3 is used as part of the cooling process to pass the steel strip S through a magnetic field. Mid-term 7.11 will be carried out.

The steel strip S is influenced by magnetism at a temperature below one Curie point, and cooling in an RA magnetic field exhibits a substantial effect at a temperature below one Curie point. In particular, by carrying out the process when the cooling zone temperature passes through the A2 transformation point during the vii frying, the magnetic properties are improved gracefully. Figure 12 shows the relationship between the temporary temperature of the raw steel plate and the cooling effect in the magnetic field. For example, G, s
In the case of wt%Si steel strip, the temperature t1 is the Gyuri point, and the temperature t2 is the A2 transformation point, and cooling in the magnetic field is started from a temperature Ts (for example, 750 ° C.), which is higher than the normal temperature, and passes through the temperature t2. and ends at temperature TF.

13 to 15 show an example of the configuration of the magnetic field intermediate J, 11 equipment, in which the magnetic field application coil 8 staged in the cold DI furnace is constructed from a hollow copper tube 9, and this 1i4 tube 9 Cool inside! l! i! By passing through the coil 10, 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.

N3, the outer surface of the copper tube 9 is coated with an insulating film 11 (SiQ2
etc.) are formed.

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. 16 shows another example of the configuration.B) A nozzle 12 for supplying cold N1 gas to the inside of the coil is installed at the steel strip outlet side of the magnetic field application phase coil 8. A cooling gas introduction duct 15 and a hood 14 are provided at the coil 8 portion and the lower part, and the cooling gas is supplied to the outside of the coil by a fan 13.

FIG. 17 shows that in the apparatus shown in FIGS. 13 to 15, the intervals between the magnetic field applying coils 8 (the intervals between the steel pipes) are changed sequentially or stepwise from the entrance side of the steel strip S to the exit side C. By making the magnetic field denser, uniform cooling and improved magnetic field cooling effect can be achieved. In other words, the denser the coil, which is the cold fJI body, the higher the cooling speed of the steel strip. Therefore, by passing the steel strip S through such a coil, as shown in the figure, It is possible to cool the steel strip S at a constant rate, thereby achieving uniform cooling in the thickness direction of the steel strip, resulting in a smooth transition of transformation and the erosion of the magnetic properties. Also, 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 LA field in the low temperature range below the Curie point, especially at the A2 transformation point. Therefore, a large cooling effect in the magnetic field can be obtained by making the coil dense on the low temperature side and applying a strong magnetic field at least when passing the two transformation points above.

In the a3 magnetic field, -[Contrary to the description, a structure is adopted in which the spacing between the magnetic field applying coils 8 is made dense on the entrance side of the steel strip S, and gradually becomes sparse toward the exit side. It's also possible. In such a structure, the quenching of the steel strip is 7 Tl, and the steel strip is relatively dense until the steel strip passes through the Δ2 transformation. It is also possible to ensure a cooling effect in the magnetic field. .

Furthermore, in the present invention, the steel strip S is plastically worked by rolling before, after, or during the cooling in the magnetic field.

As mentioned above, in the CVD process, carbon on the steel strip surface is diffused in the form of r'ecJl 2 due to the vapor deposition reaction, and the thickness of the steel strip decreases. Si vapor deposition tends to become non-uniform due to non-uniformity of
There are variations in plate thickness in the longitudinal direction. Therefore, in the present invention, the steel strip S in the warm state is rolled (skin pass rolling or normal rolling). By rolling, the thickness of the plate is made uniform, and this rolling can also be used to correct the shape and adjust the surface roughness.

In the present invention, a high-silicon A#4 strip is used as a manufacturing yarn, and therefore plastic working is performed by rolling in a warm state where the temperature of the steel strip S is about 200 to 600 degrees Celsius.
If the temperature is less than 0.degree. C., the desired plastic workability cannot be obtained. The plastic working by this rolling may be performed before, after, or during the magnetic field intermediate step 7JI. As previously mentioned,
16 At the IJ port halfway through lifting, the steel strip temperature has reached the Δ2 transformation point (6.5%
S i #A(f) When passing through PA (approximately 300°C), applying an LA field has a particularly large effect of improving magnetic properties. It is preferable to combine plastic working by cooling in a magnetic field and rolling so that vA midway 1 is performed when passing through this Δ2 transformation point. For example, the following combinations of image processing can be considered.

■ - Diffusion treatment, first cooling) Jl - Cooling in magnetic field - Rolling - Final cooling - Cold winding■ - Diffusion treatment, Cooling, Lifting, mid-rotation, Rolling - Warm winding■ - Wave number processing, First 111] Cooling (cooling to about 600 to 400°C) - Rolling - Midway through the magnetic field Nl (-Final cooling) -
Cold rolling ■ -Diffusion treatment - initial cold yJ! (Cool to about 6oo~400℃ 1) - Rolling - Cooling in magnetic field - Warm winding ■ - Diffusion treatment - Initial cooling = RA cooling in the field - Rolling - Cooling during 161113 (- Final cooling) - Cold winding - Diffusion treatment - Initial cooling - Intermediate cooling in a magnetic field - Rolling - Cooling in a magnetic field - Warm winding The steel strip S is usually rolled in a warm state from room temperature to 300°C. In general, steel strips with a high 81 content (for example, 4.0% or more) and a relatively thick plate are preferably rolled in a warm manner.

As shown in (2), after rolling in the magnetic field 141, it is rolled up in a warm state.

FIG. 3 shows a concrete structural example of a cooling furnace for performing cooling in a magnetic field and plastic working by rolling. An intermediate chamber 16 is installed in the middle of the cooling furnace 4. A skin pass mill 11 is provided. A magnetic field applying coil 8 is disposed in the front cooling chamber 41 at the front stage of this intermediate chamber.

For example, when carrying out the steps (1) and (2) above using such equipment, the steel strip S leaving the diffusion furnace 3 is cooled to a predetermined temperature in the front cooling chamber 41 of the cooling furnace 4, and then continues to be heated to 1aJ.
It is cooled in-situ to a warm state by passing through the fA applying coil 8, then rolled in a skin pass mill 17 in an intermediate chamber 16, and rolled up as it is in a warm state without being subjected to final cooling. Alternatively, it is subsequently cooled to room temperature in the rear cooling chamber 42 and then rolled up.

In the actual line, a plate thickness word and profile t1 are provided upstream of the mill, and the mill is controlled based on the detection of the plate thickness and plate shape.

Further, in the present invention, after the above-mentioned plastic working through the heat treatment, cooling and rolling, an insulating film coating can be continuously applied to the steel strip, and the steel strip can be rolled up after the baking step 111j. Figure 2 shows the continuous processing line for this purpose.
is a coating device, and 7 is a baking furnace.

Electrical steel sheets are usually used in a laminated state, in which case tI? 1
Each layer of steel needs to be insulated. For this reason, electric and steel plates are coated with an insulating film. A steel strip with a Si content of 4.0% or more is a brittle material at room temperature, and hardly undergoes plastic deformation. For this reason, if the insulating film coating is performed on a separate line from the CVD treatment line, there is a risk that the steel strip will break during unwinding or unwinding of the coil. Therefore, in the present invention, after disintegration processing by diffusion treatment, cooling, and rolling, an insulating paint is applied to the steel strip S in a coating device δ6, 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. Examples of inorganic paints used include magnesium phosphate, chromic anhydride, silica sol, and the like, and plastic resins and the like are used as tangible paints. The paint is applied to the steel strip S using a roll coater method, one-way spray method, etc., and is coated with an insulating film at a temperature of approximately 800°C in the case of inorganic paints, and 200°C or more in the case of organic paints - baking treatment. When performing this, the timing of performing the magnetic field midway u1 becomes a problem.

Zunawara, in the baking process after coating, the 4 legs are 700mm
Baking may occur at high temperatures north of °C, so if high temperature baking is performed in this way, cooling in a magnetic field may be performed in the pre-process CVD process immediately after dispersion. disappears.

Therefore, in the process involving insulation film coating and baking 1 treatment, cooling in a magnetic field can be performed in the cooling process of coating baking (depending on the J temperature, etc., during the cooling process of diffusion treatment or the cooling process after baking F4 treatment. The reheating temperature at which the effect of halfway month 1 disappears is around 650°C, so if the baking temperature is higher than 650°C, the baking temperature will increase again during the cooling process after baking. When the temperature is less than 650°C, it is preferable to perform magnetic field cooling 2JI on the cold N1 overculm after the CVD treatment and the diffusion treatment.

Generally, when baking an inorganic paint, use a steel strip of 800
℃, and therefore in this case, there is no point in heating the magnetic field halfway before heating, and baking NJ
It is preferable to perform magnetic field cooling in the cold month 1 process after treatment. In addition, in the case of organic coating r1, the baking temperature of about 200 to 300° C. is sufficient, and in this case, the intermediate rJI of the magnetic field can be actually removed in the cooling process after the CVD treatment and the diffusion treatment.

- Jg, magnetic field cold IJI, in some cases CVL) treatment - cold 7J+ process and coating after diffusion treatment - baking f4
It can be carried out in both the cold 7JI process after treatment.

For continuous professional wrestling involving such insulating film coating and baking process Fl+, the combination of 13() to 16 in-situ cooling and plastic processing by rolling (11) can be considered, for example, as follows: It will be done.

■ - Diffusion treatment - Initial cooling - Intermediate cooling in magnetic field - Rolling - Final cooling N1 - Insulating film coating - Baking treatment - Cooling - Cold rolling■ - Diffusion treatment - First time cooling 7Jl - Cooling in magnetic field U1 - Rolling -
・Final cooling - Insulating film coating - Baking treatment (-cooling) - Warm rolling ■ - Diffusion treatment - Initial cooling (cooling u1 from 600℃ to 400℃) - Mid-rolling DI (-final cooling) - Insulating film coating - Baking treatment - Cooling - Cold rolling■ - Diffusion treatment - Initial cooling (June 1st to about 600-400℃) - Rolling and cooling during magnetic lifting (-Final cooling fJl) - Insulating film coating - Baking Processing (-Cold 2JI) - Warm winding ■ - Diffusion treatment - Initial cooling - Magnetic field intermediate cooling - Rolling - In-situ cooling W (- Final cooling) - Insulating film coating - Baking treatment - Cooling - Cold winding ■ - Diffusion treatment - Initial cooling 1 - Cold N1 in magnetic field - Rolling -・
Mid-magnetic field DI (-Final cooling) - Insulating film coating - Baking treatment - Cold IJ - Rolling during drying ■ - Diffusion treatment - Initial cooling fJI - Rolling - Final cooling - Insulating film coating - Baking treatment (=Initial cooling) - 1 inch Field cooling DI (-final cooling)
- Cold or warm rolling - Diffusion treatment - Initial cooling - Cooling in RA magnetic field - Final cooling fJl - Insulating film coating - Baking treatment L! I! (−
Initial cooling) - Cooling in a magnetic field (4111 cooling) - Cold or warm rolling ■ - Diffusion treatment - Initial cooling (cold part from 600 to 400°C) - Rolling 1 - Halfway through magnetic lifting DL - Final cooling 1 - Insulating coating Coating-Basing treatment (-Initial cooling)-Magnetic field intermediate rJ+ (
- Final cold N+) - Cold or GEL warm winding CVD processing speed to enable continuous processing of steel strip J:
In order to increase the SiC in the atmospheric gas, as mentioned above,
It is necessary to optimize the treatment temperature at 04i11 degrees, but in addition to this, 5iCJ 4 diffusion to the surface of the steel strip is added.
By promoting the diffusion of OC,02 from the steel strip surface, it becomes possible to further increase the CVD processing speed.

Conventionally, it has been believed that if the flow of reactive gas is avoided too much during CVD processing, voids will occur in the deposited layer, and the purity of the deposited layer will also be reduced.Therefore, the idea that gas flow should be kept to the minimum necessary has been established. Ta.

However, in the research conducted by the present inventors, by suppressing the gas flow in this way, the reaction gas diffuses to the base material interface and the reaction by-products 111111j2 from the interface surface layer.
CVD91! is not carried out smoothly and therefore takes a long time to process, and gas flow is suppressed.
! III! It has been found that a distribution occurs in the reaction gas 'fA degree in the furnace, resulting in non-uniformity in the thickness of the deposited film.

Based on these facts, we further investigated the results and found that in the CVD processing furnace, the blowing nozzle blows the atmosphere gas onto the material to be treated, or the atmosphere is forced to circulate using a fan, etc. 5iCJ) 4 to the steel strip surface and the reaction products 1'cC, Q2 from the steel strip surface, and the CVD process is carried out at a high deposition rate while suppressing the non-uniformity of the deposited film. It has been found that it is possible to improve the CV l) processability by blowing atmospheric gas onto the surface of the steel strip using a blowing nozzle. Fig. 6 shows the implementation status of this nozzle spraying method, in which the spraying is carried out in the CVD treatment furnace 2 facing the steel strip S (=
A J nozzle 5 is arranged to blow atmospheric gas containing SiCl 2 /l onto the surface of the steel strip. Figure 7 (a) and (“
1) shows the situation where the spray nozzle 5 blows at right angles to the steel strip surface, or at right angles to the steel strip surface as shown in (A), or (
As shown in 1), it can be blown from an oblique direction.

The Si enrichment rate per unit time due to such nozzle spraying increases in proportion to the increase in the flow velocity of the gas impinging on the steel strip surface, but even if the flow velocity is increased excessively, the reaction U! Because of the speed, the Si-enriching effect cannot be expected. Generally, a flow rate of 5 Nm/SCc or higher produces an effect of -17.

The heating furnace 1 described in J3 and +fQ performs non-oxidation heating, and for this reason, heating methods such as electric indirect heating, induction heating, radiant and buoy 1 indirect heating, direct fire reduction heating, etc. are used in class A or in an appropriate combination. A heating method is used. In addition, when adopting an indirect heating method, a pretreatment such as electric washing is performed prior to heating. For example, the following heating methods including pre-treatment are adopted: ■ Pre-treatment - [Pre-heating] - Electrical indirect heating (or induction heating) ■ Pre-treatment - [Pre-heating] - Radian 1 to Duplex heating - Electric indirect heating Heating (or induction heating) ■ [Preheating] - Direct fire reduction heating - Electrical indirect heating (or induction heating) ■ Pretreatment - [Preheating] - Radiant tube indirect heating (1? Radian tube method) % formula % J5, there are no particular limitations on the cold rJl method in the cold IJ+furnace 4, but each scale cooling u1 method such as gas jet cooling, mist cooling, radiation cooling, etc. can be adopted in the form of intermediate types or combinations.

As stated above, the present invention is suitable for manufacturing steel strips with a high silicon content of 1α, such as 6.5% Si steel strips, but conventionally, the rolling method There is an advantage that high-silicon steel strips with a Si content of about 2 to 4%, which are often deformed and have poor resistance during production, can be easily produced.

[Example 1 0 Example-1 A small OVD processing furnace was used to improve CVD processability.
The effects of iCJI4 concentration and CVD treatment temperature were investigated. The results are shown in FIGS. 8 and 9.

In the figure, 8 is the atmosphere method, and 15 is the CVD process without blowing the nozzle]! In the case shown in FIG. 6, B shows the case in which CVD treatment is carried out using the nozzle blowing method, while blowing atmospheric gas onto the steel strip surface at a flow rate of 0.5 TrL/S as shown in FIG. In addition, the Si' filtration ratio refers to the initial S of the base material.
It shows the increase in Si loading after 1 ri of CVD treatment for i-sheet.

According to this, a significant Si enrichment effect is obtained at a 5iC14 temperature of 5% or higher and a CVD treatment temperature of 1023° C. or higher. Also, in the case of the same strip A'1, in the case of a method of spraying atmospheric gas with a spray nozzle, simply 'cwI' in the atmosphere.
It can be seen that a much superior Si enrichment effect (CVD processability) is obtained compared to the case where the strip is passed through the plate.

Figure 10 shows the deposition time and Si concentration in the steel strip (RJ material Si
l+evaporation), Si: 3%, plate thickness 0
, 5B steel strip was subjected to CVD treatment at 5iC94FJ degree of 21% and treatment temperature of 1150°C. Muo, in the nozzle spray method, the slit nozzle has J,
Atmospheric gas was blown at a flow rate of 0.2 NyfL/sec from a direction perpendicular to the steel strip. As can be seen from the figure, 6
．． It takes 7 minutes to remove the Si equivalent to 5% Si steel using the atmosphere method, but the nozzle blowing method B
I was able to process it in 15 minutes.

Figure 11 shows the relationship between the collision gas flow velocity and the Si enrichment ratio of the steel strip (same as Figures 8 and 9) in the nozzle blowing method. The Si enrichment ratio of the Cn4 band is increasing.

O Example-2 Continuous block OI shown in Figure 1? Due to the
Steel strips were produced with different diffusion treatment times depending on the deposition process, and the degree of Si diffusion and magnetic properties of these steel strips were investigated.

Specifically, the plate thickness is 0.3! +5, board width 900m+ Si
A steel strip containing 3% copper is used, and the line speed is set to 5.
The CVD process was carried out by changing the passage time of the diffusion furnace by avoiding changes within the range of 5 Qmpm.In addition, in order to prevent the Si vapor deposition from changing due to differences in line speed, CVD was changed according to the line speed. ) SiCl in atmospheric gas) 4 '1rHJl! , and the amount of atmospheric gas sprayed from the gas spray nozzle to adjust the amount of Si vapor deposition to be constant regardless of the line speed.

In this example, the average Si concentration including the base material was 6. ．． 5w
Si/i was vapor-deposited using t% Donaru J, Una In addition, for steel strips with a short history of diffusion treatment, Si in the surface layer
Since the amount was very large, it was rolled up at a warm temperature (250 to 300°C) to prevent cracking of the surface layer.

Figure 20 shows the steel strip as CVD treated and the diffusion time 5.
The Si1 degree and rem degree of the cross section in the plate thickness direction were measured by XMA for the above steel strips after 40 minutes of diffusion treatment (1200℃). Si is diffused.

Figure 21 shows the results of measuring the iron loss, which is a magnetic property, for a 1t cycle obtained under the same conditions as above but varying the diffusion time. ) It can be seen that sufficiently high magnetic properties, which are almost the same as those obtained when Si is uniformly diffused, are obtained in the Si diffusion state.

O Example-3 Regarding the same material steel strip as in Example-2, continuous bub [1 hiss caused various SiCl! Atmosphere rcVD at 4111 degrees Table 1 As shown, residual voids were observed in 5iCJ 430% and 35%. Therefore, 5iC14F1 degree 30%, 3
For 5%, the processing temperature is A> 1200℃ constant X'IO minutes [3) 120G'CX 5 minutes - + 1250℃ x 5 minutes C
) 1200℃ x 3 minutes → 1250℃ x 3 minutes → 1280
Steel strips were manufactured at a temperature of 3/4 °C and their residual voids were investigated. The results are not shown in Table 2.

Table 2 By selecting the diffusion treatment conditions as shown above, 5iCJ
At 1435%, a product that is somewhat satisfactory can be obtained. However, in reality, a temperature of 5iCJ of 49 degrees and 30% or less is preferable, which allows the void to become an oil source with some temperature control.

O Example-4 9■D treatment-diffusion treatment J! I! The resulting steel strip was cooled in a magnetic field during the cooling process, and its magnetic properties were investigated.

Figure 18 shows the results of A. In the figure, ■ indicates the case where magnetic field cooling is not applied, ■ and ■ are the materials of the present invention, and behind this, ■
When a magnetic field of 300e is applied by a coil wound with equal pips 'C, ■ is shown in Figure 16. are shown respectively.

Also, ■' and ■' are comparison materials in which vaporized Si is uniformly diffused in the steel strip, and of these, ■' is the same as ■, and ■' is the same as ■, with a magnetic field of 2J] It has been subjected to As is clear from the figure, the material of the present invention has magnetic properties comparable to those of the comparative material because Si is uniformly diffused. In addition, a strong magnetic field is particularly applied before and after passing the Δ2 transformation point. It can be seen that extremely excellent magnetic properties are obtained by carrying out 7JI in a strong magnetic field using the formula 6 shown in FIG. 17.

○ Example-5 The skin pass mill shown in Fig. 3 was incorporated into the 1 continuous process shown in Fig. 1.
3. The steel strip containing 3.5% Si is used as the base material, and the
At line speed of 0.3051I11, target thickness is 0.3051I11.
A steel strip containing 6.5% Si with a width of 900M was fabricated.

At this time, add 1 steel strip to each of the next 4 strips f1! LJ was built. Incidentally, the mum diffusion treatment was carried out at 1200°C for 10 minutes.

Δ) CVI) treatment, A"80%, SiCl 42
It is carried out in a 0% atmosphere and skin pass rolling is not carried out.

B) The same CVD treatment as in Δ) was performed, and skin bath rolling was performed.

C) CVD treatment, Ar80%, SiC, ll4
A 20% reaction gas was sprayed onto the steel strip using a nozzle spraying method to give a 0.5
It is carried out by colliding with gas rolling at Nm/sec, and skin bath rolling is not carried out.

D) CVD treatment was performed in the same manner as in C), and skin bath rolling was performed.

Table 3 shows the results of measuring the plate thickness deviation (increase/decrease from the target plate thickness) and surface roughness for the samples in each case, and shows that the plate thickness is uniform with high precision by skin bath rolling. It can be seen that

[Effects of the Invention] According to the present invention described above, a high-silicon steel strip with crushed magnetic properties can be obtained by short-term CVD treatment and diffusion heat treatment in a continuous line, and it is possible to obtain a high-silicon steel strip with crushed magnetic properties by CVD treatment at a temperature of 1200°C or less. Because of the treatment, problems such as poor shape of the steel strip and melting of edges may occur.In addition, it is possible to ensure excellent toughness and uniform plate thickness without following the magnetic properties of the steel strip. Therefore, high-quality high-silicon steel sheets can be efficiently manufactured without increasing the length of the line.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory views of continuous processing lines for implementing the method of the present invention. FIG. 3 is an explanatory diagram showing a specific example of the cooling furnace shown in FIGS. 1 and 2. FIG. FIG. 4 is a state diagram of the re-3i system. , FIG. 5(^), and (B) show changes in the Si degree distribution in the thickness direction of the steel strip, which is suitable for the diffusion heat treatment of the present invention. Figures 6 and 7 ω, CV by the (YU is nozzle blowing) method
FIG. 6 is an overall explanatory diagram, and FIG. 7 (ω and elongation) are explanatory diagrams for the nozzle blowing method. Figure 8 shows 5iCJ in gas during CVD processing!
4 Relationship with Si enrichment ratio of C1 steel strip, Figure 9 shows CV
The relationship between the D treatment temperature and the steel strip Si enrichment ratio is shown. FIG. 10 shows the 37.00 hours during the opening hours when Sii arrives in the present invention.
The relationship between the degree of Fig. 12 shows the relationship between the impinging gas flow velocity, Si enrichment of the steel strip, and J11 ratio. Fig. 12 shows the relationship between the plate temperature of a silicon steel plate and the cooling effect in a magnetic field. Figures 13 to 15
The figures show an example of the configuration of a cooling equipment in a magnetic field. Fig. 13 is a perspective view, Fig. 14 is a sectional view of an uncoiled state, and Fig. 15 is a sectional view of a steel pipe constituting a coil. Fig. 16 is an explanatory diagram showing an example of the configuration of the ta magnetic field cooling equipment. Fig. 17 is an explanatory diagram without showing the preferred equipment of the VIi in-field cooling intermediate 1 and the magnetic field cooling method used therefor. Fig. 18 shows the magnetic properties in the case of magnetic field cooling in comparison with that in the case of simple cooling. Fig. 19 shows the thermal cycle taken in the example. Fig. 20 ( a)～
(C) shows 5ili minutes of each sample material in the example. FIG. 21 shows the magnetic properties of each sample material in Examples. In the figure, 1 is a heating furnace, 2 is a CV I) treatment furnace, 3 is a diffusion treatment furnace, 4 is a cooling furnace, and 6 is a coating device r1.
7 is a firing (= J furnace, 8 is a coil for applying a magnetic field, 9 is a skin pass mill, and S is a steel strip. 301o 6.5% Si Concentration Fig. 13 Fig. 15 Fig. 1゜ Fig. 16 Fig. 17 oooooooooo” “00”””mtwacM'g
--Line Direction Figure 21 Solitary Harvest Clearance Procedures Amendment (Spontaneous) 1981 1 June 25) 1 Ki Pursu? 11Jj<1・, Tono Ugaoibe (1
mouth 1 lord) 1 1kf'
Display of l 1986 Patent Application No. 71492 Bow 2 All town names ++1! In the sequel line! ,'1°H Silicon steel strip manufacturing method (412) 1.1 Mokukokan Co., Ltd. 41 Agent 5 Attachment 11 of the Yustop Fri Ordinance 7 Contents of the amendment As shown in the attached sheet Amendment content 7 Honton Specification Cattle No. 14 At the end of the negative 4th line, the phrase “It will be a big thing,” is corrected to “It will be a big thing.” In the 40th negative line of the second part, the phrase “by scrap rolling” is corrected to “At the waste flow rate.” do.

Claims (4)

[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. During the diffusion treatment, the diffusion treatment is stopped while the surface layer Si concentration is higher than the Si concentration at the center in the thickness direction of the steel strip, to obtain a steel strip in which the Si concentration is non-uniform in the thickness direction. High silicon steel strip in a continuous line characterized by cooling the steel strip in a magnetic field in the subsequent cooling process and plastically working the steel strip by rolling in a warm state before, after, or during the cooling in the magnetic field. Production method. (2) Steel strip with SiCl_4 at a mol fraction of 5 to 35%
In a non-oxidizing gas atmosphere containing SiCl_4, silicon was continuously treated by chemical vapor deposition at a temperature of 1023 to 1200°C, and then S in a non-oxidizing gas atmosphere containing no SiCl_4.
When conducting the diffusion treatment to diffuse i into the steel strip, the diffusion treatment is stopped while the surface layer Si concentration is higher than the Si concentration at the center of the steel strip in the thickness direction, so that the Si concentration is non-uniform in the thickness direction. In the subsequent cooling process, the steel strip is cooled in a magnetic field, and before, after, or during the cooling in the magnetic field, the steel strip is plastically worked by rolling in a warm state, and after final cooling, an insulating coating is formed. A method for producing high silicon steel strip in a continuous line, characterized by coating and baking treatment. (3) Steel strip with SiCl_4 at a mol fraction of 5 to 35%
In a non-oxidizing gas atmosphere containing SiCl_4, silicon was continuously treated by chemical vapor deposition at a temperature of 1023 to 1200°C, and then S in a non-oxidizing gas atmosphere containing no SiCl_4.
When conducting the diffusion treatment to diffuse i into the steel strip, the diffusion treatment is stopped while the surface layer Si concentration is higher than the Si concentration at the center of the steel strip in the thickness direction, so that the Si concentration is non-uniform in the thickness direction. During or after the subsequent cooling process, the steel strip is plastically worked by rolling in a warm state, and after final cooling, it is coated with an insulating film and baked, and in the subsequent cooling process, it is cooled in a magnetic field. A method for producing high-silicon steel strip on a continuous line featuring features. (4) Steel strip with SiCl_4 at a mol fraction of 5 to 35%
In a non-oxidizing gas atmosphere containing SiCl_4, silicon was continuously treated by chemical vapor deposition at a temperature of 1023 to 1200°C, and then S in a non-oxidizing gas atmosphere containing no SiCl_4.
When conducting the diffusion treatment to diffuse i into the steel strip, the diffusion treatment is stopped while the surface layer Si concentration is higher than the Si concentration at the center of the steel strip in the thickness direction, so that the Si concentration is non-uniform in the thickness direction. In the subsequent cooling process, the steel strip is cooled in a magnetic field, and before, after, or during the cooling in the magnetic field, the steel strip is plastically worked by rolling in a warm state, and after final cooling, an insulating coating is formed. A method for manufacturing high silicon steel sheets in a continuous line, characterized by coating and baking treatment, followed by cooling in a magnetic field in the cooling process.