JP2001098329A - Manufacturing method of non-oriented electrical steel sheet with excellent magnetic properties - Google Patents

Abstract

(57) [Problem] To provide a method for manufacturing a non-oriented electrical steel sheet excellent in magnetic properties with low iron loss and high magnetic flux density. SOLUTION: In weight%, C: 0.01% or less, Si: 1.8%
Hereinafter, Mn: 0.05 to 1.5%, sol. Al: 0.05 to 0.20%, S:
0.0010 to 0.020%, P: 0.2% or less, N: 0.0010 to 0.00
50%, B: contains 2 to 30 ppm, and the product of the content of sol.Al and B satisfies the following formula (1), and after hot rolling a slab substantially composed of Fe, the temperature is 800 ° C. or more. After hot-rolled sheet continuous annealing at, cold rolling, finish annealing once or twice with intermediate annealing, or strain relief annealing (SRA
). (Equation 1)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a non-oriented electrical steel sheet having excellent magnetic properties.

[0002]

2. Description of the Related Art In recent years, the need for higher efficiency of electrical equipment has been rapidly increasing, and it is necessary to further reduce iron loss and magnetic flux density in magnetic steel sheets, which are iron core materials of motors and transformers. Has occurred. Methods for reducing iron loss include Si and
A method of increasing the specific resistance by adding Al is well known, but the addition of a large amount of Si or Al causes a decrease in iron loss and a decrease in magnetic flux density at the same time. Therefore, high-temperature winding of a hot-rolled coil, continuous annealing of a hot-rolled sheet, box annealing of a hot-rolled sheet, and the like have been practiced as means for simultaneously realizing low iron loss and high magnetic flux density.

[0003] While the improvement of the characteristics of magnetic steel sheets is being pursued,
In steel production, various new smelting processes are being studied from the viewpoint of cost reduction, and the impurity level in steel sheets tends to increase. For example, in the iron making process, low-grade ore is used, and in the steel making process, the blowing time is shortened and scrap is actively used, and the amount of Cr, V, Nb, Ti, etc. mixed tends to increase. Since the grain growth of the steel sheet containing such impurities is remarkably reduced, sufficient properties can be improved even when the hot-rolled coil is heated at a high temperature, the hot-rolled sheet is continuously annealed, and the hot-rolled sheet box is annealed. No effect.

[0004] From such a background, for example, Japanese Unexamined Patent Publication No.
No. 74257 and JP-A-59-74258 disclose S, O, N
And a technique of reducing the amount of Ti, Zr, Ce, and Ca to perform hot-rolled sheet annealing.

On the other hand, JP-A-58-117828 and JP-A-58-117828
JP-151453 discloses a nitride morphology control technique based on B addition. In this technique, N is fixed with B to increase the coarseness of the nitride. To control B / N to around 1, tens of ppm of B is added, and Al is added for several hundred ppm for deoxidation.
ppm is added.

As a technique for controlling the form of nitride, addition of a large amount of Al has been known for a long time. However, in order to sufficiently coarsen AlN, 0.2% or more of Al must be added, which causes a problem of cost increase. Occurs. Furthermore, the addition of a large amount of Al promotes the reduction reaction of Ti-based oxides floating and separated in the slag at the steelmaking stage and Zr-based oxides present in the refractory, so that mixing of Ti and Zr etc. This leads to an increase in volume. Therefore, while the addition of a large amount of Al improves the grain growth properties, it also has the disadvantage of increasing the variation in characteristics.

JP-A-58-52425 and JP-A-1-139721 disclose a technique for stabilizing the magnetic flux density at a high level by devising a manufacturing method. In this technique, a hot-rolled sheet is slightly reduced before annealing of the hot-rolled sheet to promote uniform grain growth.

[0008]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open
In the techniques described in JP-A-59-74257 and JP-A-59-74258, reduction of such impurities causes a great increase in cost and production restrictions.

JP-A-58-117828 and JP-A-58-15145
The technique described in Japanese Patent Publication No. 3 has a problem that unless B is added in an equal amount to N, the grain growth is remarkably deteriorated and the magnetic flux density is essentially low.

The techniques described in JP-A-58-52425 and JP-A-1-139721 have problems in that the anisotropy of the steel sheet after finish annealing becomes extremely large and that the cost is increased.

The present invention has been made in order to solve the above problems, and has as its object to provide a method for producing a non-oriented electrical steel sheet having excellent magnetic properties with low iron loss and high magnetic flux density.

[0012]

Means for Solving the Problems The present inventors have conducted intensive studies on the effects of components and manufacturing conditions on the magnetic properties of electrical steel sheets, and as a result, found that a slab containing an appropriate amount of sol. Performing strip annealing, specifically, containing 0.05% to 0.20% of sol.Al to precipitate a small amount of AlN during hot rolling,
By adding an appropriate amount of B to precipitate BN at the time of finish rolling and performing hot-rolled sheet annealing, the magnetic properties are improved. By adding an appropriate amount of Sn and / or Sb, the magnetic flux density is further improved. , As a result, harmful as impurities
It has been found that V can be rendered harmless and that the magnetic properties do not deteriorate even when added up to 0.2%.

The present invention has been made based on such findings, and is solved by the following invention.

In the first invention, C: 0.01% or less, Si: 1.8% or less, Mn: 0.05 to 1.5%, sol.
~ 0.20%, S: 0.0010 ~ 0.020%, P: 0.2% or less, N
: 0.0010 to 0.0050%, B: contains 2 to 30 ppm and so
l. The product of the content of Al and B satisfies the following formula (5), and after hot rolling a slab consisting essentially of Fe, and then subjecting the hot-rolled sheet to continuous annealing at a temperature of 800 ° C or higher, 1 This is a method for producing a non-oriented electrical steel sheet having excellent magnetic properties, characterized by performing cold rolling, finish annealing, or further performing strain relief annealing (SRA) twice between round and intermediate annealing.

[0015]

(Equation 5)

In the second invention, C: 0.01% or less, Si: 1.8% or less, Mn: 0.05 to 1.5%, sol.
~ 0.20%, S: 0.0010 ~ 0.020%, P: 0.2% or less, N
: 0.0010 to 0.0050%, B: contains 2 to 30 ppm and so
l. The product of the content of Al and B satisfies the following formula (6), and after hot rolling a slab consisting essentially of Fe, and then performing hot-rolled box annealing at a temperature of 680 ° C or higher, This is a method for producing a non-oriented electrical steel sheet having excellent magnetic properties, characterized by performing cold rolling, finish annealing, or further performing strain relief annealing (SRA) twice between round and intermediate annealing.

[0017]

(Equation 6)

In the third invention, C: 0.01% or less, Si: 1.8% or less, Mn: 0.05 to 1.5%, sol.
~ 0.20%, S: 0.0010 ~ 0.020%, P: 0.2% or less, N
: 0.0010 to 0.0050%, B: contains 2 to 30 ppm and so
l. The product of the content of Al and B satisfies the following equation (7), and after hot rolling a slab substantially composed of Fe, winding at a temperature of 720 ° C. or more, and performing self-annealing, This is a method for producing a non-oriented electrical steel sheet having excellent magnetic properties, characterized by performing cold rolling, finish annealing, or further performing strain relief annealing (SRA) twice between round and intermediate annealing.

[0019]

(Equation 7)

According to a fourth aspect of the present invention, there is provided a magnetic recording medium having excellent magnetic properties according to the first to third aspects, wherein the product of the contents of sol. Al and B satisfies the following formula (8). This is a method for manufacturing a grain-oriented electrical steel sheet.

[0021]

(Equation 8)

According to a fifth invention, in the method for producing a non-oriented electrical steel sheet according to the first invention to the fourth invention, one or two of Sn and Sb are contained in the slab as Sb + S
This is a method for producing a non-oriented electrical steel sheet having excellent magnetic properties, characterized by containing 0.002 to 0.2% as n / 2.

According to a sixth aspect of the present invention, there is provided the method of manufacturing a non-oriented electrical steel sheet according to the first to fifth aspects, wherein the slab contains V: 0.2% or less as a component. This is a method for producing a non-oriented electrical steel sheet having excellent characteristics.

According to a seventh aspect of the present invention, there is provided the method for producing a non-oriented electrical steel sheet according to the first to sixth aspects, wherein Ti: 15 ppm or less, Nb: 15 ppm or less, Z
r: A method for producing a non-oriented electrical steel sheet having excellent magnetic properties, characterized by containing 15 ppm or less.

[0025] In these means, "substantially Fe" refers to those containing other trace elements, including unavoidable impurities, within the scope of the present invention unless the effects of the present invention are lost. Means that Further, in this specification, all the percentages indicating the components of steel are% by weight, and pp
m is also ppm by weight.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention and the reasons for limiting the present invention will be described below in detail.

First, the effects of sol. Al and B on magnetic properties were investigated. C: 0.002%, Si + Al: 0.8
%, Mn: 0.3%, P: 0.10%, S: 0.003%, Cr: 0.05
%, V: 0.002%, N: 0.0025%, and sol.Al: 0.03
鋼 0.23%, B: steel changed to 2 to 32 ppm was melted in a 50 kg vacuum melting furnace. Then, after subjected to hot rolling
Winding treatment was performed at 600 ° C for 1 hour. Then 2 hours at 780 ° C
r was hot rolled and cold rolled to 0.5 mm. Then, after performing a finish annealing at 820 ° C. for 30 seconds, the magnetic properties were measured. Some further at 750 ° C
The magnetic properties were measured by performing strain relief annealing (hereinafter abbreviated as SRA) for 2 hours. As for the magnetic characteristics, iron loss and magnetic flux density were measured by a 25 cm Epstein test method.

The magnetic properties of the obtained sample after SRA,
FIG. 1 shows the relationship between sol. Al and B. Generally, in B-added steel, Al is added at about 0.03% for the purpose of deoxidation.
First, the effect of B on magnetic properties was investigated with sol.Al fixed at 0.03%. As is evident from FIG. 1, when the sol.Al content was 0.03%, the iron loss was high, the magnetic flux density was low, and good magnetic properties could not be obtained at any B content. In order to investigate the cause, a chemical analysis of the precipitate from the extraction residue and observation of the precipitate by an electron microscope (hereinafter referred to as TEM) were performed. As a result, in the sample having a low B content, that is, the sample having a B / N <1 by weight ratio, fine AlN having a diameter of several nm is precipitated during the hot-rolled sheet annealing. In samples with / N> 1, excessively added B remains in the steel as solid solution B, and this fine AlN and solid solution B may deteriorate grain growth during hot-rolled sheet annealing and subsequent annealing. found. In addition, B is 10
It has been found that the addition of B in excess of 1515 ppm also reduces the magnetic flux density by the addition of B itself. Although the details are unknown, it is considered that this is due to a decrease in the transformation point due to the addition of B and a change in the texture during hot rolling. In any case, it has been difficult to obtain a steel sheet excellent in both iron loss and magnetic flux density with the conventional steel.

Therefore, in order to solve such a problem,
An attempt was made to improve grain growth while minimizing the amount of B added. That is, one of the causes of such deterioration of magnetic properties is AlN which is finely precipitated during annealing of a hot-rolled sheet. Therefore, an attempt was made to increase the amount of Al added in order to prevent such fine precipitation.
As shown in FIG. 1, it was found that when sol. Al and B were contained in an appropriate range, both iron loss and magnetic flux density were significantly improved. In the content range of sol.Al and B, it was also confirmed that AlN was precipitated during hot rolling to prevent fine precipitation, and that BN and AlN were frequently precipitated in a complex manner. It is thought that this greatly improves the grain growth and significantly improves the magnetic properties. From the above, the proper range of sol.Al and B for obtaining good magnetic properties is
As the product of these,

[0030]

(Equation 9)

It is necessary to control to the range represented by Furthermore, in order to obtain good magnetic properties, it is important to reduce the amount of solid solution B remaining at the end of hot rolling and AlN precipitated alone as much as possible. Therefore, more preferably, sol.Al
The range of B is the product of these,

[0032]

(Equation 10)

It is desirable to control to the range represented by the following. However, if the added amount of B is less than 2 ppm or exceeds 30 ppm, the magnetic properties deteriorate regardless of the amount of sol.Al. Therefore, the addition amount of B needs to be 2 ppm or more and 30 ppm or less.

If sol. Al is added in excess of 0.20%, the addition of Al causes a substantial deterioration of the magnetic flux density, and at the same time raises the problem of cost increase and the magnetic characteristics become unstable due to the mixing of Ti and Zr. There is also a negative effect. Therefore, in the present invention, sol.
The range of Al is 0.05% to 0.20%.

The scope of the present invention is shown in FIG.
As a gray part, a more preferable range is shown as a gray part.

However, in the case of a relatively low grade steel containing 0.5% or less of Si, a fine grain structure was slightly observed in the surface layer of the steel sheet after finish annealing and after SRA. When the surface layer of the steel sheet on which the fine grain structure was generated was polished to about 20 μm and TEM observation was performed with an extraction replica, it was observed that AlN of about 100 nm was densely precipitated. In other words, Al has a strong affinity with N
It is considered that the surface layer nitridation was caused by the combined addition of B and B and a fine grain structure was formed.

Therefore, from the viewpoint of preventing surface nitriding, C
: 0.002%, Si: 1.0% and 0.3%, Mn: 0.5%, P
: 0.10%, S: 0.003%, Cr: 0.05%, V: 0.002
%, Sol.Al: 0.08%, N: 0.0025%, B: 10ppm
Sb: Stained steel changed to tr to 0.3%, obtains a sample by the same method as in Fig. 1, and affects the magnetic flux density after SRA.
The effects of Si and Sb were investigated. The result is shown in figure 2. In addition,
The measurement of the magnetic flux density was performed by a 25 cm Epstein test method.

Although the magnitude of the effect differs depending on the amount of Si added, both the sample containing 1.0% Si and the sample containing 0.3% Si contain 0.002% or more of Sb.
The magnetic flux density after SRA is improved. Observation of the precipitates by TEM confirmed that the fine-grained structure of the surface layer disappeared in accordance with the improvement of the magnetic flux density. Also, set Sb to 0.
Addition of 02% or more further improves the magnetic flux density. On the other hand, when Sb is added in an amount of 0.2% or more, iron loss is deteriorated due to excessive Sb in any of the samples.

The same effect can be obtained by the addition of Sn, and the amount of Sn to be added is equal to that of Sb.
It was confirmed that twice the amount was required. Therefore, in the present invention, one or two of Sb and Sn are expressed as Sb + Sn / 2 at 0.002%
It is desirable that the content be contained in an amount of about 0.2%.

Next, the effect of V on the magnetic properties was investigated. V has long been recognized as an element that deteriorates the grain growth of steel. However, in the present invention, N
Is fixed by Al and B, and even if V is added to some extent, it may be possible to make the steel sufficiently harmless without deteriorating the grain growth of the steel.

Therefore, C: 0.002%, Si: 0.6%, Mn:
0.3%, P: 0.10%, S: 0.003%, Cr: 0.07%, sol.
Al: 0.1%, N: 0.0025%, B: 10 ppm, V: tr.
Samples of steel varied in the range of ~ 0.25% were obtained in the same manner as in Fig. 1, and the effect of V on the magnetic properties after finish annealing and after SRA was investigated. FIG. 3 shows the relationship between the V content and the magnetic properties. According to FIG. 3, in the component system of the present invention in which B and sol.Al are added in combination, if V is 0.2% or less,
It has been found that the magnetic properties do not deteriorate even if mixed or added. The precipitate was analyzed using the extraction residue.
If it was 2% or less, almost no V-based precipitate was detected. However, when V exceeded 0.2%, V-based precipitates were slightly detected, and the magnetic properties deteriorated. Therefore,
It is desirable that the content of V be 0.2% or less.

Although Cr does not precipitate by itself,
V is an element that degrades magnetic properties when mixed. That is, it is an element that induces precipitation by the precipitation of VN, and a part of V is replaced by Cr to form (V, Cr) N. In this respect, in the component system in the range of the present invention, if V is 0.2% or less, precipitation of VN itself is suppressed, so that deterioration of magnetic properties due to Cr content can be avoided.

It is known that Ti, Nb and Zr as impurities other than Cr and V deteriorate magnetic properties. These are elements that are difficult to detoxify because they form not only nitrides but also carbonitrides. Therefore, in order to prevent such contamination, use of a special refractory or a special operation form in steelmaking is forced.

In order to clarify the influence of Ti, Nb and Zr on the magnetic properties, C: 0.002%, Si: 0.8%, Mn: 0.3
%, P: 0.10%, S: 0.003%, Cr: 0.03%, V: 20pp
m, sol.Al: 0.1%, N: 0.0025%, B: 12ppm
A steel having a range of Ti: 0 to 50 ppm, Nb: 0 to 50 ppm, and Zr: 0 to 50 ppm was melted, and a sample was obtained in the same manner as in FIG. The relationships between Ti, Nb, and Zr and iron loss after finish annealing and after SRA are shown in FIGS. 4, 5, and 6, respectively. In addition, the measurement of iron loss was performed by a 25 cm Epstein test method.

FIGS. 4, 5 and 6 show that iron loss is deteriorated when Ti, Nb and Zr all exceed 15 ppm. Therefore, it is desirable that their contents be 15 ppm or less (including 0 ppm).

Next, the reasons for limiting other components will be described. C: 0.01% or less, preferably to avoid magnetic aging
0.005% or less (including 0%).

Si: An element effective for increasing the specific resistance of a steel sheet and reducing iron loss, but if added in excess of 1.8%, the above-described effect of the combined addition of Al and B is lost. Therefore, the upper limit is set to 1.8% (including 0%).

Mn: Usually added for the purpose of preventing red hot brittleness during hot rolling and improving grain growth. Further, in the present invention, BN
Is indispensable as an element to precipitate MnS, which is required as a precipitation site of, in the steel sheet. From the above viewpoint, the lower limit is 0.05%
Above. Further, when the content exceeds 1.5%, the magnetic flux density is reduced, so the upper limit is set to 1.5%.

S, like Mn, is an essential element for the precipitation of MnS, and 0.0010% or more is required for the precipitation of MnS. However, if the content exceeds 0.020%, the grain growth is reduced, so that 0.020%
% Or less.

P: an element necessary for improving the punching property of the steel sheet, but if added in excess of 0.2%, the steel sheet becomes brittle, so that the content is 0.2% or less (including the case of 0%).

N: an essential element for precipitating AlN during hot rolling, 0.0010% or more is required for AlN precipitation. However, when the content exceeds 0.0050%, the precipitation amount of AlN increases and the grain growth property decreases, so the content is set to 0.0010% to 0.0050%.

Next, the effect of the hot-rolled sheet annealing conditions on the magnetic properties was investigated. C: 0.002%, Si + Al: 0.8%,
Mn: 0.3%, P: 0.10%, S: 0.003%, Cr: 0.05%,
V: 0.002%, sol. Al: 0.09%, N: 0.0025%, B: 10
Steel containing ppm was melted in a 50 kg vacuum melting furnace. The obtained ingot is heated to 1200 ° C, and the finish rolling temperature is set to 830 ° C.
After hot rolling to a sheet thickness of 2.2 mm, the sheet was wound at a temperature of 600 to 690 ° C. Thereafter, after hot-rolled sheet annealing under the conditions shown in Table 1, cold rolling was performed to 0.5 mm. Then at 820 ° C
The magnetic properties were measured after 30 seconds of finish annealing. Thereafter, SRA was performed at 750 ° C. for 2 hours, and the magnetic properties were measured in the same manner. As for the magnetic characteristics, iron loss and magnetic flux density were measured by a 25 cm Epstein test method. Table 1 shows the measurement results of the magnetic properties together with the manufacturing conditions.

[0053]

[Table 1]

From Table 1, it can be seen that in the present invention, most of nitrides and sulfides are formed into coarse precipitates of 200 to 300 nm which are combined with each other, and are hardly affected by impurities. It can be seen that the effect of hot-rolled sheet annealing can be sufficiently obtained even at a relatively low temperature. For long-term annealing assuming hot-rolled sheet box annealing (hot-rolled sheet annealing condition in Table 1 is 2 hours), 680
Magnetic properties are improved at a temperature of ℃ or more, short-time annealing assuming continuous annealing of hot-rolled sheet (Hot-rolled sheet annealing condition in Table 1 is 2 min)
The magnetic properties were improved at temperatures above 800 ° C. Therefore, the annealing temperature of hot-rolled sheet is 800 ° C or more in continuous annealing,
For box annealing, the temperature is 680 ° C or higher.

Also, after winding at a temperature of 720 ° C. or more, the heat insulating cover of the coil is attached and the self-annealing of the hot-rolled coil is carried out at 800 ° C. or more, or at 680 ° C. or more. The same effect as in case of box annealing can be obtained.
Keep it at 720 ° C or higher. However, continuous annealing, box annealing, for the heating above Ac ₁ point in either case of a self annealing the magnetic flux density is degraded, it is desirable to below this temperature.

Next, another manufacturing method will be described.
In the present invention, a slab having a predetermined component is hot-rolled,
Next, continuous annealing of hot-rolled sheet at a temperature of 800 ° C or more, 680 ° C
After performing either hot-rolled box annealing at the above temperature or winding at a temperature of 720 ° C or more and self-annealing,
It can be obtained by performing one or two cold rollings with intermediate annealing, finish annealing, or further performing strain relief annealing (SRA).

The slab heating temperature is preferably lower from the viewpoint of grain growth. Further, in order to obtain a high magnetic flux density, it is desirable to apply a rolling reduction of 30% or more at Ar ₃ or less during hot rolling, and finish rolling is completed in the ferrite region. The cold rolling reduction is desirably 50 to 75%. Furthermore, in order to obtain a high magnetic flux density after SRA, a higher finish annealing temperature is desirable. However, when heated to more than the Ac ₁ point, the anisotropy is reduced, but the magnetic flux density in the L direction is greatly deteriorated. Therefore, the finish annealing temperature needs to be ₁ Ac or less.

[0058]

[Example] Molten steel blown in a converter was degassed, adjusted to the components shown in Table 2, cast, and heated at 1200 ° C.
Hot rolling was performed to a thickness of 2.0 mm. The finishing temperature of the hot rolling was 830 ° C, and the winding temperatures were 600 ° C, 680 ° C, and 720 ° C. After pickling, hot-rolled sheet annealing was performed, followed by cold rolling to a sheet thickness of 0.5 mm. Next, finish annealing was performed, and the magnetic characteristics were measured. Also, for some, 75
The magnetic properties were measured by applying SRA at 0 ° C for 2 hours.

The magnetic properties were measured for iron loss and magnetic flux density using a 25 cm Epstein test piece. Table 3 also shows the manufacturing conditions and magnetic properties of each steel sheet.

[0060]

[Table 2]

[0061]

[Table 3]

From Table 3, it can be seen that, in the present invention example in which the steel sheet components and the manufacturing conditions are controlled within the range of the present invention, a steel sheet having a low iron loss and a high magnetic flux density can be obtained.

On the other hand, in the comparative example, after the finish annealing or the SR
At least one of iron loss after A and magnetic flux density after finish annealing or after SRA was inferior.

Further, it can be understood that the same effect as in the other examples of the present invention can be obtained by attaching the heat retaining cover of the coil after winding at a temperature of 720 ° C. or more and self-annealing the hot-rolled coil. .

[0065]

As described above, according to the present invention, a non-oriented electrical steel sheet having both low iron loss and high magnetic flux density and excellent magnetic properties can be obtained. Furthermore, since the steel sheet according to the present invention is not easily affected by impurities, there is no need to reduce impurities, and there is an advantage that stable production can be performed at lower cost than in the prior art.

Further, since the steel sheet according to the present invention has excellent magnetic properties, it is suitable as a core material for motors and transformers.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between sol. Al content, B content and magnetic properties.

FIG. 2 is a diagram showing the relationship between the Sb content and the magnetic flux density after SRA.

FIG. 3 is a diagram showing the relationship between V content and magnetic properties.

FIG. 4 is a graph showing the relationship between Ti content and iron loss after finish annealing and after SRA.

FIG. 5 is a graph showing the relationship between Nb content and iron loss after finish annealing and after SRA.

FIG. 6 is a graph showing the relationship between the Zr content and iron loss after finish annealing and after SRA.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) H01F 1/16 H01F 1/16 A (72) Inventor Yasushi Tanaka 1-2-1, Marunouchi, Chiyoda-ku, Tokyo F-term (reference) in Nippon Kokan Co., Ltd. 4K033 AA01 CA02 CA03 CA05 CA06 CA08 CA09 FA10 FA13 HA01 HA03 JA01 QA02 RA03 SA03 SA04 UA02 5E041 AA02 AA11 AA19 CA02 CA04 HB05 HB07 HB11 NN01 NN18

Claims (7)

[Claims] (1) C: 0.01% or less, Si: 1.8% by weight
Hereinafter, Mn: 0.05 to 1.5%, sol. Al: 0.05 to 0.20%, S:
0.0010 to 0.020%, P: 0.2% or less, N: 0.0010 to 0.00
50%, B: contains 2 to 30 ppm, and the product of sol.Al and B content satisfies the following formula (1), and after hot rolling a slab substantially composed of Fe, the temperature is 800 ° C. or more. After hot-rolled sheet continuous annealing at, cold rolling, finish annealing once or twice with intermediate annealing, or strain relief annealing (SRA
A) a method for producing a non-oriented electrical steel sheet having excellent magnetic properties. (Equation 1) 2. In% by weight, C: 0.01% or less, Si: 1.8%
Hereinafter, Mn: 0.05 to 1.5%, sol. Al: 0.05 to 0.20%, S:
0.0010 to 0.020%, P: 0.2% or less, N: 0.0010 to 0.00
50%, B: contains 2 to 30 ppm, and the product of the content of sol. Al and B satisfies the following formula (2), and the remainder substantially consists of Fe. After hot-rolled box annealing in, cold rolling, finish annealing once or twice with intermediate annealing, or strain relief annealing (SRA)
A method for producing a non-oriented electrical steel sheet having excellent magnetic properties. (Equation 2) 3. In% by weight, C: 0.01% or less, Si: 1.8%
Hereinafter, Mn: 0.05 to 1.5%, sol. Al: 0.05 to 0.20%, S:
0.0010 to 0.020%, P: 0.2% or less, N: 0.0010 to 0.00
50%, B: contains 2 to 30 ppm, the product of the contents of sol. Al and B satisfies the following formula (3), and after hot rolling a slab substantially composed of Fe, the temperature is higher than 720 ° C. After rolling and self-annealing, cold rolling, finishing annealing once or twice with intermediate annealing, or strain relief annealing (SR
A) A method for producing a non-oriented electrical steel sheet having excellent magnetic properties, wherein the method is performed. (Equation 3) 4. The method for producing a non-oriented electrical steel sheet having excellent magnetic properties according to claim 1, wherein the product of the contents of sol.Al and B satisfies the following expression (4). (Equation 4) 5. The method for producing a non-oriented electrical steel sheet according to claim 1, wherein one or two of Sn and Sb are further added as a component in the slab by weight% to Sb + Sn /
2. A method for producing a non-oriented electrical steel sheet having excellent magnetic properties, characterized by containing 0.002 to 0.2% as 2. 6. The method for producing a non-oriented electrical steel sheet according to claim 1, wherein the slab contains V: 0.2% by weight or less as a component in the slab. Manufacturing method of excellent non-oriented electrical steel sheet. 7. The method for producing a non-oriented electrical steel sheet according to claim 1, wherein the components in the slab are as follows: Ti: 15 ppm or less, Nb: 15 ppm or less, Zr: 15 by weight%.
A method for producing a non-oriented electrical steel sheet having excellent magnetic properties, characterized by containing less than ppm.