JPH05125495A - Nonoriented silicon steel sheet excellent in magnetic property - Google Patents

Abstract

PURPOSE:To reduce iron loss and to improve magnetic flux density by specifying respective contents of C, Si, Mn, P, S, Al, and N and also specifying the (Ge)eq. specified by the contents of Sb and Sn. CONSTITUTION:The nonoriented silicon steel sheet has a composition consisting of, by weight, <=0.005% C, 0.1-3.5% Si, 0.1-0.9% Mn, <=0.2% P, <=0.015% S, <=1.5% Al, <=0.005% N, 0.003-0.01% Ge, 0.01-0.1% (Ge)eq., and the balance Fe. The (Ge)eq. is defined as being equal to %Ge+(%Sb+%Sn)/2 [where %Ge means Ge content, %Sb means Sb content, and %Sn means Sn content]. The above steel sheet is reduced in iron loss and has high magnetic flux density.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-oriented electrical steel sheet having a low iron loss and a high magnetic flux density.

[0002]

2. Description of the Related Art It is important for non-oriented electrical steel sheets used as iron core materials for motors, transformers, etc. to have low iron loss and high magnetic flux density in order to save energy in electrical equipment. In particular, in recent years, in order to achieve downsizing and high efficiency of equipment, there has been an increasing demand for development of a material having a higher magnetic flux density than ever while keeping iron loss low. Non-oriented electrical steel sheets are classified into grades according to their iron loss and magnetic flux density. Generally, high grade materials are S
Although the i content is increased to reduce the iron loss, the magnetic flux density also decreases as the Si content increases. On the other hand, since the low grade material has a low Si content, the saturation magnetic flux density is prevented from decreasing, and a relatively high magnetic flux density can be obtained, but there is a problem of high iron loss. Therefore, low iron loss and high magnetic flux density cannot be achieved merely by adjusting the amount of Si, and appropriate measures must be taken.

Improvements in chemical composition, especially S
Several attempts have been made to improve iron loss or magnetic flux density by adding special elements such as b and Sn. For example, with respect to the addition of Sb, JP-A-54-68717,
JP-A-58-147563, JP-A-61-44124
JP-A-55-15 for the addition of Sn and the like.
8252, JP-A-56-98420, JP-A-56-
No. 102520 has been proposed. In addition, JP-A-62
-180014, JP-A-64-39348, JP-A-2-263952, and the like, a technique relating to the combined addition of Sn and Cu is disclosed in JP-A-59-157259 and JP-A-63-
No. 33518 discloses a technique related to the combined addition of Sn and Mn, and Japanese Patent Laid-Open No. 63-317627 discloses a technique involving Ni and M.
Techniques relating to the composite addition of n are disclosed respectively.

[0004]

However, among the above-mentioned proposals, those relating to the addition of Sb are not sufficient to reduce the iron loss because the main purpose is to improve the magnetic flux density, and conversely, those relating to the addition of Sn. Has a problem that the improvement of the magnetic flux density (especially the magnetic flux density in a high magnetic field region) is insufficient because the main purpose is to reduce the iron loss. In addition, both technologies use Sb,
Because of the segregation of Sn at the grain boundaries, long-time hot-rolled sheet annealing, intermediate annealing at two cold pressures, and some technologies require strain relief annealing by the user, which avoids process complexity and cost increase. Absent. In addition, Sn + Cu, Sn + Mn, Mn
In the technique of performing composite addition of + Ni and the like, in order to fully exert the effect, the composite addition amount of these elements is 1.0 to
It is necessary to be 1.5 wt% or more, and as a result, the saturation magnetic flux density is inevitably lowered, and as a result, the improvement of the magnetic flux density itself is not so large.

As described above, the conventional techniques cannot sufficiently improve both the iron loss and the magnetic flux density at the same time, or require the hot-rolled sheet annealing for a long time, the two cold pressing method, and the strain relief annealing by the user. However, there is a problem that the process is complicated and the cost is inevitable.

To address such a problem, the present applicant has previously
Based on the new finding that the effect of improving the magnetic characteristics can be obtained by adding Ge, a technique capable of avoiding the above-mentioned problems was proposed as Japanese Patent Application No. 3-84691. That is, Ge
By adding an appropriate amount, the iron loss and magnetic flux density are sufficient by adopting a normal manufacturing method without complicating the process and increasing the cost due to long-time hot-rolled sheet annealing or double cold pressing. It has been clarified that an improved steel sheet can be obtained.

The present invention is based on a technique for improving the magnetic characteristics by adding such Ge, and further advances this technology to realize a further cost reduction while maintaining the effect of improving the magnetic characteristics by adding Ge. Is to provide.

[0008]

DISCLOSURE OF THE INVENTION The present inventors have re-examined and considered the advantages and disadvantages of each element added to the steel sheet on the premise that the magnetic properties are improved by adding Ge. as a result,
Sb and Sn have a problem in improving the magnetic properties as described above when they are added individually or in combination with other elements which have been conventionally studied. However, when Sb and Sn coexist with Ge. Does not have such a problem, and can exhibit the same excellent magnetic property improving effect as Ge, and therefore, a part of Ge can be replaced with relatively inexpensive Sb and Sn,
It has been found that this makes it possible to achieve a sufficient improvement in magnetic characteristics equivalent to the case of adding Ge alone, while achieving cost reduction.

As will be described in detail later, the essence of the present invention is G
Sb or Sn or Sn and Sn in the coexistence with e
Is to add Sb and Sn
It was also confirmed that the same effect can never be obtained by the combination of the above, or the combination of Sb or Sn with other elements such as Cu and Mn in the prior art. That is, the magnetic property improving effect obtained by adding Sb and Sn in the coexistence with Ge is based on the effect which is clearly different from the conventional technique, and is the first to be examined and considered by the present inventors. It has been revealed.

The present invention has been made on the basis of the above findings, and its constitution is as follows: C: 0.0050 wt% or less,
Si: 0.1 wt% or more and 3.5 wt% or less, Mn: 0.
1 wt% or more and 0.9 wt% or less, P: 0.2 wt% or less, S: 0.015 wt% or less, Al: 1.5 wt% or less, N: 0.0050 wt% or less, Ge: 0.0030
Contains more than wt% and less than 0.0100 wt%, and S
b or Sn, one or two of them may be combined with [Ge] eq. = 0.0100 to 0.1000, where [Ge] eq. =% Ge + (% Sb +% Sn) /
2% Ge: Ge content (wt%)% Sb: Sb content (wt%)% Sn: Sn content (wt%) contained so as to satisfy the magnetic characteristics of the balance Fe and unavoidable impurities. It is an excellent non-oriented electrical steel sheet.

[0011]

Next, the function and effect of the present invention will be described together with the reason for the limitation. First, the component composition of the steel sheet of the present invention will be described.

(1) Ge amount Steels A to D listed in Table 1 were melted to form slabs. Among these steel group A to steel group D, steel group A is Si:
0.14 wt%, Al: tr. , Si + Al≈0.14
For the following steels containing 1 wt%, the Ge amount was set to tr.
Various additions were made within the range of (no addition) to 0.0130 wt%. No Sb, Sn additive (Steel A-1) Sb: 0.083 wt% addition (Steel A-2) Sn: 0.123 wt% addition (Steel A-3) Sb: 0.056 wt%, Sn: 0.025 wt% Addition (Steel A-4)

Steel group B has Si: 1.42 wt% and Al:
For the following steels containing 0.098 wt% and Si + Al≈1.52 wt%, the Ge amount was set to tr. (Additive-free)~
Various additions were made within the range of 0.0130 wt%. No Sb, Sn additive (Steel B-1) Sb: 0.026 wt% addition (Steel B-2) Sn: 0.041 wt% addition (Steel B-3) Sb: 0.013 wt%, Sn: 0.030 wt% Addition (Steel B-4)

Steel group C has Si: 1.63 wt% and Al:
For the following steels containing 0.272 wt% and Si + Al≈1.90 wt%, the Ge amount was set to tr. (Additive-free)~
Various additions were made within the range of 0.0130 wt%. No Sb, Sn additive (Steel C-1) Sb: 0.166 wt% addition (Steel C-2) Sn: 0.098 wt% addition (Steel C-3) Sb: 0.099 wt%, Sn: 0.063 wt% Addition (Steel C-4)

The steel group D has Si: 3.05 wt% and Al:
For the following steels containing 0.511 wt% and Si + Al≈3.56 wt%, the Ge amount was set to tr. (Additive-free)~
Various additions were made within the range of 0.0130 wt%. Sb, Sn no addition (Steel D-1) Sb: 0.019 wt% addition (Steel D-2) Sn: 0.032 wt% addition (Steel D-3) Sb: 0.012 wt%, Sn: 0.024 wt% Addition (Steel D-4)

These slabs were subjected to hot rolling-cold rolling-finish annealing, or hot rolling-hot rolled sheet annealing-cold rolling-finish annealing under the conditions shown in Table 2 to obtain a sheet thickness of 0.5 mm. The steel plate of After that, ring-shaped test pieces were punched out from these steel sheets, and their magnetic characteristics were measured to evaluate the magnetic characteristics as the omnidirectional average value of the steel sheets.

FIGS. 1 to 4 show the results arranged for each of the steel group A to the steel group D by the amount of Ge. According to these drawings, not only the amount of Si and the amount of Al but also C, M
In any of the steel groups A to D having different contents of n, P, S, and N, that is, regardless of the base component, the presence or absence of hot-rolled sheet annealing, and the annealing when performing hot-rolled sheet annealing. It is understood that the effect of improving the magnetic properties of Ge can be partially replaced by Sb or Sn regardless of the process conditions such as the length of time or the finish annealing temperature. That is, the following common results are recognized with respect to FIGS. 1 to 4 having different base components and process conditions.

(A) When Sb and Sn are not added and only Ge is added (No. 1 steel of each steel group), Japanese Patent Application No. 3-84
As disclosed in No. 691, Ge: 0.0100 wt%
Above magnetic properties are significantly improved with (magnetic flux density B ₅₀ is increased, the iron loss W _15/50 drops).

(B) In the case of adding Sb or Sn (No. 2 and No. 3 steel of each steel group) or simultaneously adding Sb and Sn (No. 4 steel of each steel group), Ge:
Even if it is less than 0.0100 wt%, the improvement in magnetic characteristics equivalent to that of the above (a) is achieved. However, in this case also Ge
There is a lower limit to the amount, that is, the necessary minimum amount. However, the lower limit is that the addition amount of Sb and Sn is Sb: 0.012
0.166 wt%, Sn: 0.024 to 0.123 wt
%, It is constant at 0.0030 wt% regardless of the added amounts of Sb and Sn.

(C) Ge: If less than 0.0030 wt%, Sb is 0.166 wt% and Sn is 0.123 at the maximum.
Even if added by wt% (Steel C-2 and Steel A-3) or added by 0.162 wt% as the sum of Sb and Sn (Steel C-4), the improvement margin of the magnetic properties is as described above ( Much smaller than a).

Thus, even if Ge is not added in an amount of 0.0100 wt% or more, if the amount of Ge added is 0.0030 wt% or more, the rest is added with Sb or Sn or Sb.
It can be replaced by the combined addition of Sn and Sn, and it can be seen that the magnetic characteristics can be remarkably improved as in the case where 0.0100 wt% or more of Ge is added alone. As described above, the essence of the present invention is that, while maintaining the remarkable effect of improving the magnetic properties of Ge, a part of Ge is relatively inexpensive.
b and Sn are used to substitute for cost reduction. For this purpose, the amount of Ge is at least 0.0030 wt% as described above.
Was necessary, and therefore, this was made the lower limit of the Ge amount of the present invention. On the other hand, when Ge: 0.0100 wt% or more, S
The characteristics are remarkably improved only by adding Ge alone without special addition of b and Sn, and the margin for improving the characteristics by addition of Sb and Sn is small. Therefore, in the present invention, the Ge amount is 0.01
It was defined as less than 00 wt%.

One of the requirements of the present invention is that the S
b, Sn is added, but the most important requirement is G
It is essential to add e. Considering Ge, Sb, and Sn, as a combination of composite addition, a combination including Ge defined in the present invention, that is, Ge + Sb,
Besides Ge + Sn and Ge + Sb + Sn, a combination of Sb + Sn is also conceivable. This is No. 1 among the steel groups listed in Table 1. Ge amount of 4: tr. 1 to 4, the magnetic properties of this steel are Sb or S.
There is no great difference from the n-added steel (steel containing Sb or Sn added to the extent corresponding to the amount of Sb + Sn), and the value is Ge + S.
It is far inferior to the steel of the combination of n or Ge + Sb.

Specifically, for example, in FIG. 1, Si + Al≈
Results for 0.14 wt% steel are shown, Sb:
0.056 wt%, Sn: 0.025 wt%, Sb + S
S containing n: 0.081 wt% and Ge: 0 wt%
b, Sn compound addition steel, Ge: 0wt%, Sb: 0.0
Sb containing 83 wt% (substantially the same as 0.081 wt% which is the Sb + Sn amount of the above Sb and Sn composite added steel)
It shows only the same magnetic characteristics as the single-added steel, and the value of the magnetic characteristics is Ge: 0.0030 wt% or more, and is significantly inferior to the steel containing Sb or Sn. Further, the same results are obtained for the steels of FIGS. 2, 3, and 4 having different amounts of Si + Al. This means that the combined addition of Sb and Sn containing no Ge is essentially the same as when Sb or Sn alone is added in an amount substantially equal to the combined addition amount, and it is exceptionally different from the combined addition of both elements. Meaning that the meaning and effect of is not seen. Further, the inventors of the present invention also conducted the same study on steel containing a combination of elements such as Cu and Mn and Sb or Sn shown in the prior art.
It was confirmed that the combined addition had no special significance or effect. On the other hand, in the combination of Ge, Sb, and Sn defined in the present invention, the magnetic properties are dramatically improved as described above, the presence of Ge is essential, and in the coexistence with Ge, Sb, Only by adding Sn, a remarkable improvement in magnetic properties was achieved. This means that the addition of Sb and Sn in the coexistence with Ge has a clearly different effect from the combined addition in the case where Ge is not included.

(2) Amount of Sb and Sn In the skeleton of the present invention, a part of Ge is relatively inexpensive Sb and Sn while maintaining an excellent effect of improving the magnetic characteristics by adding Ge.
There is to substitute. In this case, as for the amounts of Sb and Sn, naturally, there is an appropriate range for them.

Steels A to D shown in Table 3 were melted to form slabs. Among these steel group A to steel group D, steel group A is
Si: 0.14 wt%, Al: tr. , Si + Al≈
0.14 wt%, Ge: 0.0030 to 0.0080 w
It is a steel containing t% and adding Sb and Sn in the following ranges. Sb: tr. To 0.2300 wt% (steel A-5) Sn: tr. Added in the range of 0.2 to 300 wt% (Steel A-6). ~ 0.1500wt% addition (Steel A-7)

The steel group B contains Si: 1.42 wt%,
Al: 0.098 wt%, Si + Al≈1.52 wt
%, Ge: 0.0030 wt% to 0.0080 wt%, and Sb and Sn are added in the range of to below. Sb: tr. To 0.2300 wt% (steel B-5) Sn: tr. Added in the range of 0.2 to 300 wt% (Steel B-6). Added in the range of 0.1500 wt% (Steel B-7)

Steel group C has Si: 1.63 wt% and Al:
0.272 wt%, Si + Al≈1.90 wt%, G
e: Steel containing 0.0030 to 0.0080 wt% and Sb and Sn added in the range of to below. Sb: tr. To 0.2300 wt% (Steel C-5) Sn was added in the range of tr. Added in the range of 0.2 to 300 wt% (Steel C-6). ~ 0.1500wt% addition (Steel C-7)

Steel group D has Si: 3.05 wt% and Al:
0.511 wt%, Si + Al≈3.56 wt%, G
e: Steel containing 0.0030 to 0.0080 wt% and Sb and Sn added in the range of to below. Sb: tr. Added in the range of 0.2300 wt% (Steel D-5). To 0.2300 wt% (steel D-6) Sb and Sn were added in the respective tr. Added in the range of ~ 0.1500 wt% (Steel D-7)

These slabs were subjected to hot rolling-cold rolling-finish rolling, or hot rolling-hot rolled sheet annealing-cold rolling-finish annealing under the conditions shown in Table 4, and having a sheet thickness of 0.5 mm. A steel plate was obtained. After that, ring-shaped test pieces were punched out from these steel sheets, and their magnetic characteristics were measured to evaluate the magnetic characteristics as the omnidirectional average value of the steel sheets. At this time, the inventors of the present invention have studied to formulate the Ge equivalent (hereinafter referred to as [Ge] eq.) On the premise that the Ge is partially replaced by Sb and Sn, which is the main feature of the present invention. I went. As a result, [Ge] eq. =% Ge + (% Sb +% Sn) / 2 However, the equivalent formula of% Ge: Ge content (wt%)% Sb: Sb content (wt%)% Sn: Sn content (wt%) is obtained, The magnetic properties of this [Ge] eq. It is possible to arrange in this [Ge] eq. It has been found that by controlling the P content within an appropriate range, it is possible to obtain magnetic properties equivalent to those in the case of the above-described Ge single addition steel. This means that when an appropriate amount of Ge coexists, Sb and Sn are added to this [Ge] eq. Has the effect of improving the magnetic properties defined by the above, and therefore the amount of Sb and Sn added is [Ge] eq. Must be specified by This will be specifically described below.

FIGS. 5 to 8 show the magnetic properties of the above-mentioned steel group A to steel group D by [Ge] eq. According to these drawings, Ge: 0.0030 to 0.0080w
Within the range of the present invention of t%, the steel group A having different contents of C, Mn, P, S and N as well as Si and Al contents
In any of the steel D groups, that is, regardless of the base component, the presence or absence of hot-rolled sheet annealing, when hot-rolled sheet annealing is added, regardless of process conditions such as its length or finish annealing temperature, Sb Or Sn or both, and [Ge] eq. The With 0.0100 wt% or more, increases significantly Ge added alone like the steel flux density B ₅₀ disclosed above, and the iron loss W _15/50 is seen to be reduced dramatically.

By the way, as one of the effective means for improving the magnetic properties, hot-rolled sheet annealing can be mentioned. [Ge] e
q. ≈0% and [Ge] eq. ≧ 0.0100wt
%, The magnetic property difference is [Ge] eq. It is equal to or more than the margin for improving the magnetic properties by the addition of the hot-rolled sheet annealing at ≈0%. 0.01
It is possible to quantitatively grasp how great the effect of improving the magnetic characteristics by setting the content to be at least 100 wt%.

Regarding the magnetic flux density, [Ge] e
q. In the region of ≧ 0.0100 wt%, the [Ge] e
q. Dependency is relatively small, 0.0400-0.060
The amount is gradually reduced at 0 wt% or more. On the other hand, regarding the iron loss, in the range of 0.0100 to 0.1000 wt%, [Ge] eq. Shows a very low value with little dependence on [Ge] eq. If it exceeds 0.1000 wt%, grain growth is inhibited and iron loss tends to remarkably increase.
Therefore, [Ge] eq. In order to improve the magnetic characteristics by the appropriate control of [Ge] e,
q. Is required to be 0.0100 to 0.1000 wt%, which is defined as the range of the present invention.

[Ge] eq. If the
The hot rolled sheet annealing can be omitted in the composition system of Si + Al <1.7 wt% as in the case of the e-added steel. As is generally known, the presence or absence of the γ / α transformation is one branch point when considering the magnetic properties, but in the case of the present invention as well, the presence or absence of the γ / α transformation [Ge] eq. The effect of optimization is divided into γ / α
In the case of a component system with transformation, that is, S in the above example
Steel group A with i + Al content of less than 1.7 wt% (Si + Al≈
0.14 wt%) and steel group B (Si + Al≈1.52)
wt%), [Ge] eq. It can be seen that, within the range of the present invention, even if the hot rolled sheet is not annealed, the magnetic flux density and the iron loss are almost the same as those when the hot rolled sheet is annealed. On the other hand, in the case of a component system without γ / α transformation, that is, in the above example, the Si + Al amount is 1.7 w
In steel group C (Si + Al≈1.90 wt%) and steel group D (Si + Al≈3.56 wt%) of t% or more,
[Ge] eq. The effect of hot-rolled sheet annealing is recognized even in those optimized within the scope of the present invention, and the hot-rolled sheet annealing additional material is higher in magnetic flux density than the as-wound hot-rolled sheet annealing omitted material,
The iron loss is low.

By the way, in the present invention, a very small amount of Ge (0.0030 wt.
% Or more), the balance of the Ge addition amount is Sb, Sn
It has been clarified that the effect of improving the magnetic properties equivalent to that of the steel containing Ge alone can be obtained even if it is replaced by the addition of Fe.

The effect of improving the magnetic characteristics by Ge is Sb, Sn.
This is due to segregation at grain boundaries, which suppresses the development of {111} texture, which is unfavorable in terms of magnetic properties. However, in the case of Ge, the atomic radius is smaller than that of Sb, Sn, etc., and it is easy to diffuse.
Compared with b and Sn, it segregates more rapidly and more rapidly, and significantly suppresses the development of {111} texture.
And, since the diffusion speed of Ge is high in this way,
Long-time hot-rolled sheet annealing and intermediate annealing at two cold pressures, which were indispensable for Sb and Sn, etc., are not particularly necessary, and only short-time hot-rolled sheet annealing is added or hot-rolled sheet annealing is added. Even if it is not wound, the magnetic properties can be sufficiently improved.

The magnetic property improving effect of Ge is considered to be due to the fact that the grain boundary interface energy is lowered due to the segregation of Ge at the grain boundaries, in addition to the above diffusion rate. Be done. Grain boundary segregation of a predetermined amount of Ge must naturally occur in order to reduce the interface energy to some extent, but the minimum necessary addition amount of Ge for that purpose is the lower limit of the Ge amount specified by the present invention. 0030
It is considered to be wt%.

From the above points, in the case of the steel containing Ge alone disclosed above, in addition to the rapid diffusion of Ge, a small amount of Ge is segregated at the grain boundaries, which lowers the interfacial energy during segregation. Then, the subsequent segregation of Ge is further accelerated. Therefore, with a smaller addition amount than Sb, Sn, etc., grain boundary segregation occurs more rapidly and more than {1
11} It is considered that the development of the texture is significantly suppressed. Also in the present invention in which Sb and Sn are added in the coexistence of Ge, by adding Ge in an amount of 0.0030 wt% or more, first, before the grain boundary segregation of Sb and Sn,
Ge, which has a high diffusion rate, segregates at the grain boundaries, which lowers the interfacial energy for segregation and accelerates the subsequent segregation of Sb and Sn significantly compared to the Ge-free steel. It is considered to suppress the development of {111} texture. However, since the diffusion rate of Sb and Sn is slower than that of Ge, the degree of grain boundary segregation is not equal to that of Ge, and [Ge] eq. Ge as seen in 1
It becomes about / 2.

As described above, when Ge is contained in an amount of 0.0030 wt% or more, Sb and Sn also have a 1/2 effect of Ge on the suppression of {111} texture. Then, the present invention relates to [Ge] eq. By defining the addition amounts of Sb and Sn through, the addition of Sb and Sn can be made equivalent to the addition of Ge, and by this, the effect of improving the magnetic properties equivalent to that of the steel containing Ge alone can be obtained.

On the other hand, in the conventional techniques such as Sb, Sn, etc. alone added, and Sb, Sn combined addition, etc., in addition to the slow diffusion rate of these elements, when these elements segregate at the grain boundaries. , Ge does not cause the effective reduction of grain boundary interface energy and the resulting acceleration of segregation. Therefore, as described above, unless a large amount of these elements is added or a long-term segregation treatment is added, It is considered that the development of the {111} texture cannot be effectively suppressed.

(3) Other components C: This is an element that deteriorates the magnetic properties and is also harmful in terms of magnetic aging.
An extremely low carbon content of 050 wt% is essential. Si: An element that increases specific resistance and decreases iron loss, but in order to obtain this effect, addition of 0.1 wt% or more is necessary. On the other hand, if it exceeds 3.5 wt%, the steel becomes extremely brittle and cracks occur during cold rolling. Therefore, Si is 0.1
˜3.5 wt%.

Mn: Addition of 0.1 wt% or more is required to prevent hot brittleness. On the other hand, if it exceeds 0.9 wt%, the magnetic flux density is significantly deteriorated. Therefore, Mn is 0.1 to
The range is 0.9 wt%. P: To increase hardness and improve punchability,
An appropriate amount can be added. However, if it exceeds 0.2 wt%, not only these effects are saturated, but also the magnetic characteristics are rapidly deteriorated. Therefore, the upper limit is 0.2 wt%.

S: If it exceeds 0.015 wt%, the grain growth property deteriorates and the iron loss increases, so the content is made 0.015 wt% or less. Similar to Al: Si, it is an element that increases the specific resistance and reduces the iron loss, so it can be added as needed up to 1.5 wt%, but if it exceeds this, it becomes extremely brittle and impairs the cold rollability. The upper limit is set to 1.5 wt%. N: An element that deteriorates the magnetic characteristics, and in order to avoid this, it is necessary to set it to 0.0050 wt% or less.

Next, preferable process conditions for obtaining the steel sheet of the present invention will be described. In the present invention, by optimizing the component composition as described above, excellent magnetic characteristics can be obtained regardless of process conditions. Therefore, it is not necessary to pay particular attention to the process conditions, and known conditions may be used. However, when the known process conditions are randomly applied without considering the amounts of Si and Al, for example, sufficient grain growth does not occur, and as a result, iron loss is deteriorated. Therefore, even when applying known conditions, there are preferable ranges as described below.

Hot rolling conditions: If the heating temperature of hot rolling is excessively high, the surface quality will be deteriorated due to scale generation and the yield such as scale loss will be reduced. Therefore, the upper limit of the heating temperature is about 1250 ° C. It is desirable to do. Regarding the lower limit, if the heating temperature is extremely low, the rolling temperature during rolling will inevitably become low, leading to an increase in rolling load.
It is desirable to set the degree to the lower limit. Regarding the finishing temperature, when considering the heating temperature, the amount of temperature decrease until the finishing rolling, and the rolling load, a desirable range is about 900 to 700 ° C.

Regarding the winding temperature, if the hot-rolled sheet is not annealed in the next step, it is necessary to promote the recrystallization of the hot-rolled sheet or coarsen the crystal grains at this stage because of the magnetic characteristics. For this reason, it is desirable to set the winding temperature in the following range according to the amount of Si + Al. When 0.1 wt% ≦ Si + Al <1.0 wt% 630 ° C. or higher 1.0 wt% ≦ Si + Al <1.7 wt% 670 ° C. or higher 1.7 wt% ≦ Si + Al <3.0 wt% … 700 ℃ or more 3.0wt% ≦ Si + Al …… 720 ℃ or more

On the other hand, when the hot-rolled sheet is annealed, it is sufficient that recrystallization progresses and crystal grains become coarse during the hot-rolled sheet annealing.
Therefore, the winding temperature is preferably set to a low temperature of 550 ° C. or lower from the viewpoint of preventing an increase in scale and deterioration of surface properties.

Annealing conditions for hot-rolled sheet: Si + Al <1.7 wt
%, Magnetic properties almost the same as when hot-rolled sheet annealing is added without winding even without hot-rolled sheet annealing are added, so there is no need for hot-rolled sheet annealing. There is no problem in performing hot-rolled sheet annealing in order to improve the coil end property as it is, or to improve the magnetic properties to some extent.

On the other hand, in the case of Si + Al ≧ 1.7 wt%, the magnetic characteristics are improved by the addition of hot rolled sheet annealing.
It is desirable to perform hot-rolled sheet annealing if necessary. The annealing temperature in the case of performing hot-rolled sheet annealing has a desirable temperature as a lower limit in order to develop recrystallization of the hot-rolled sheet or to coarsen the crystal grains and obtain the required magnetic properties. There is a desirable temperature as an upper limit because the grains do not become too coarse and the surface quality is not deteriorated. That is, it is desirable that the annealing temperature be in the following range depending on the amount of Si + Al. 0.1 wt% ≦ Si + Al <1.0 wt% 700 to 950 ° C. 1.0 wt% ≦ Si + Al <1.7 wt% 725 to 1000 ° C. 1.7 wt% ≦ Si + Al <3.0 wt% 750 to 1050 C 3.0 wt% ≤ Si + Al ... 800 to 1100 C Note that the annealing time is preferably 30 seconds or more in order to obtain a sufficient annealing effect.

Cold-rolling conditions: There is no particular limitation, and ordinary cold-rolling may be performed once or twice or more with intermediate annealing.

Finishing annealing conditions: The finishing annealing temperature has a desirable lower limit as a lower limit in order to sufficiently grow crystal grains and obtain required magnetic properties, while the crystal grains become excessively coarse, and the surface texture is changed by oxidation. There is a desirable temperature as an upper limit to prevent deterioration. That is, it is desirable that the annealing temperature be in the following range depending on the amount of Si + Al. 0.1 wt% ≦ Si + Al <1.0 wt% 650-900 ° C. 1.0 wt% ≦ Si + Al <1.7 wt% ・ ・ ・ 700-950 ° C. 1.7 wt% ≦ Si + Al <3.0 wt% 750-1000 C 3.0 wt% ≤ Si + Al ... 850 to 1050 C Note that the annealing time is preferably 30 seconds or more in order to obtain a sufficient annealing effect.

Skin pass rolling condition: A semi-processed material which is subjected to strain relief annealing after punching into a predetermined shape by performing skin pass rolling after finish annealing. In that case, since the grain growth is sufficiently generated during the stress relief annealing, it is desirable that the reduction rate in the skin pass is 2% or more. On the other hand, if the rolling reduction is excessively large, the crystal grains become finer and the magnetic properties are deteriorated. Therefore, the upper limit is preferably about 12%.

When skin pass rolling is performed, the crystal grains are coarsened and iron loss can be reduced, but at the same time, the magnetic flux density is also reduced. A semi-processed material of a type that reduces iron loss to some extent without being significantly reduced in magnetic flux density by being subjected to stress relief annealing is also often used. The steel sheet of the present invention has a high magnetic flux density and a low iron loss at the stage of finish annealing. Therefore, the steel sheet is subjected to stress relief annealing after punching as it is, and when the semi-processed material of the above type is used, the magnetic flux density is reduced. It is possible to further reduce the iron loss while maintaining the high level, and it is possible to provide a semi-processed material having excellent magnetic properties more than ever before.

[0053]

【Example】

[Example 1] Steels E to J shown in Tables 5 to 7 were melted to form slabs, and then hot rolled, cold rolled, and finish annealed under the conditions shown in Tables 8 to 10. It was subjected to (no hot-rolled plate annealing) to obtain a steel plate having a plate thickness of 0.5 mm. The ring-shaped test pieces were punched out from these steel plates and the magnetic properties were measured, and the results are also shown in Tables 8 to 10.

As is clear from the table, the contents of C, Mn, P, S and N as well as the contents of Si and Al are different.
That is, in any of Steel E group to Steel J group having different base components, Sb, Sb,
Either one or both of Sn is added, and [Ge] eq. Steels adjusted to the scope of the present invention (N of each steel group
o. 2 steel-No. 4 steel: the steel of the present invention) is Ge,
Base steel without addition of Sb and Sn (No. 1 of each steel group)
Compared with steel), it has a significantly higher magnetic flux density and lower iron loss.

On the other hand, steel having a Ge content below the range of the present invention (No. 5 steel of each steel group: comparative steel) and [Ge] eq. However, the magnetic properties of the steel below the range of the present invention (No. 6 steel of each steel group: comparative steel) are not so different from those of Base steel, and both the magnetic flux density and the iron loss are significantly inferior to the steel of the present invention. In addition, [Ge] eq. In the case of steels exceeding the range of the present invention (No. 7 steels of each steel group: comparative steels), the magnetic flux density is improved in some cases, but the iron loss is almost the same as or rather increases with Base steel. , Excellent magnetic properties have not been achieved.

[Example 2] Steel E group shown in Table 5 to Table 7
Steel group J was subjected to hot rolling, short-time hot-rolled sheet annealing, cold rolling, and finish annealing under the conditions shown in Tables 11 to 13 to obtain a sheet thickness of 0.5.
mm steel plate was obtained. The ring-shaped test pieces were punched out from these steel plates, and the results of measuring the magnetic properties are also shown in Tables 11 to 13. According to the table, Example 1 in the case of as-rolled
Similarly to the above, even when hot-rolled sheet annealing is added for a short period of time, the steel of the present invention has significantly higher magnetic flux density-lower iron loss than Base steel, regardless of the composition and process conditions.
It can be seen that the magnetic properties of the comparative steels have not been improved so much and are significantly inferior to those of the steels of the present invention.

Example 3 Steel H described in Table 6 and Table 7
Group-Steel J group was subjected to hot rolling, long-time hot-rolled sheet annealing, cold rolling, and finish annealing under the conditions shown in Table 14 and Table 15,
A steel plate having a plate thickness of 0.5 mm was obtained. The results of measuring the magnetic properties by punching out ring-shaped test pieces from these steel plates are shown in Table 14.
Also shown in Table 15. According to the table, the steel of the present invention has a significantly higher magnetic flux density-lower iron loss than the Base steel, regardless of the components and the process conditions, even when the hot-rolled sheet is annealed for a long time. It can be seen that the magnetic properties of the comparative steel are significantly inferior to those of the steel of the present invention.

Example 4 Steel E group and steel F group shown in Table 5 were hot-rolled under the conditions shown in Table 16 and Table 17,
After cold-rolling, finish annealing (no hot-rolled sheet annealing), or hot rolling, short-time hot-rolled sheet annealing, cold rolling, finish annealing, some of them are skin-pass rolled and another The portion was not subjected to skin pass rolling and was a steel plate having a plate thickness of 0.5 mm. A ring-shaped test piece was punched out from these steel plates and
The properties as a semi-processed material were evaluated by measuring the magnetic properties after subjected to stress relief annealing at 0 ° C. for 2 hours. The results are also shown in Tables 16 and 17.

As is clear from the table, both of the steel E group and the steel F group, that is, regardless of the component system, regardless of the presence or absence of hot-rolled sheet annealing, the presence or absence of skin pass rolling, and other process conditions, The steel of the present invention has remarkably high magnetic flux density and low iron loss as compared with Base steel and comparative steel. The steel of the present invention is a semi-processed material of a type that is skin-pass rolled or a semi-processed material of a type that is not skin-pass rolled. It turns out that it is also applicable to.

[0060]

As described above, according to the present invention, the component composition, in particular, [Ge] eq. Defined by Ge amount and Ge, Sb, Sn amount is specified. By substituting Sb and Sn for a part of the excellent magnetic property improving effect of Ge by optimizing, the long-time hot-rolled sheet annealing and the intermediate annealing at two cold pressures, etc. can be performed like Ge alone addition steel. It is possible to provide a non-oriented electrical steel sheet having a high magnetic flux density and a low iron loss, which can be manufactured by a simple process without performing.

In such a steel sheet of the present invention, it is possible to reduce the cost by substituting a part of Ge with inexpensive Sb and Sn, and the manufacturing process thereof does not require a complicated process. Also, the manufacturing cost can be reduced and the product delivery can be shortened. Further, the steel sheet of the present invention has no strict restrictions on process conditions, is easy to manufacture, and is applicable not only to full-process materials but also to semi-process materials, and has a wide range of application. As described above, according to the present invention, there is an effect that a full-process material or a semi-process material of a non-oriented electrical steel sheet having excellent magnetic properties can be manufactured inexpensively, easily, and with a short delivery time.

[0062]

[Table 1]

[0063]

[Table 2]

[0064]

[Table 3]

[0065]

[Table 4]

[0066]

[Table 5]

[0067]

[Table 6]

[0068]

[Table 7]

[0069]

[Table 8]

[0070]

[Table 9]

[0071]

[Table 10]

[0072]

[Table 11]

[0073]

[Table 12]

[0074]

[Table 13]

[0075]

[Table 14]

[0076]

[Table 15]

[0077]

[Table 16]

[0078]

[Table 17]

[Brief description of drawings]

FIG. 1 is a drawing showing the influence of the amount of Ge added on the magnetic properties of Si + Al≈0.14 wt% steel (Steel Group A).

FIG. 2 is a drawing showing the effect of the added amount of Ge on the magnetic properties of Si + Al≈1.52 wt% steel (Steel B group).

FIG. 3 is a drawing showing the effect of the amount of Ge addition on the magnetic properties in Si + Al≈1.90 wt% steel (Steel C group).

FIG. 4 is a drawing showing the influence of the amount of Ge addition on the magnetic properties in Si + Al≈3.56 wt% steel (Steel D group).

FIG. 5 shows the effect of [Ge] eq. On the magnetic properties of Si + Al≈0.14 wt% steel (Steel group A). Drawing showing the effect of

FIG. 6 shows the effect of [Ge] eq. On the magnetic properties of Si + Al≈1.52 wt% steel (Steel B group). Drawing showing the effect of

FIG. 7 shows the effect of [Ge] eq. On the magnetic properties of Si + Al≈1.90 wt% steel (Steel C group). Drawing showing the effect of

FIG. 8 shows the effect of [Ge] eq. On the magnetic properties of Si + Al≈3.56 wt% steel (Steel D group). Drawing showing the effect of

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiko Nishimoto 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.

Claims (1)

[Claims] 1. C: 0.0050 wt% or less, Si:
0.1 wt% or more and 3.5 wt% or less, Mn: 0.1 wt
% Or more and 0.9 wt% or less, P: 0.2 wt% or less, S:
0.015 wt% or less, Al: 1.5 wt% or less, N:
0.0050 wt% or less, Ge: 0.0030 wt% or more and less than 0.0100 wt%, and one or two of Sb and Sn is added to [Ge] eq. = 0.0100 to 0.1000 [wt
%] However, [Ge] eq. =% Ge + (% Sb +% Sn) /
2% Ge: Ge content (wt%)% Sb: Sb content (wt%)% Sn: Sn content (wt%) so that the content is satisfied, and the balance is Fe and inevitable impurities. Non-oriented electrical steel sheet with excellent magnetic properties.