JP2001011588A - Nonoriented electric steel sheet excellent in magnetic flux density and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a high magnetic flux density material contributing to the miniaturization of motors and compact transformer apparatuses in a field of electric industry, and to provide a method for producing the same. SOLUTION: This nonoriented electric steel sheet excellent in magnetic flux density has a compsn. contg., by weight, <=0.01% C, 0.1 to 1.3% Si, 0.001 to 0.006% Al, <0.7% Mn, <=0.2% P, <=0.01% S, <=0.005% N, 0.001 to 0.1% Sn, 0.01 to 0.4% Cu, 0.01 to 0.2% Ni and 0.01 to 0.2% Cr, and the balance Fe with inevitable components and has >=1.77 T magnetic flux density B50. Moreover, as to the method for producing the nonoriented electric steel sheet excellent in magnetic flux density, a hot rolled sheet contg. the above components is subjected to hot rolled sheet continuous annealing at 800 to 1100 deg.C, is next cold-rolled and is annealed.

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 used for a core of a motor or a small transformer in the electric industry, and more particularly, to a high magnetic flux density material contributing to miniaturization of equipment and a method of manufacturing the same. According to.

[0002]

2. Description of the Related Art Today, electricity and magnetism are routinely used in human life. Historically, the beginning may have been the invention of the motor and generator by Faraday in the United Kingdom (circa 1820-1830). The electromagnetic steel sheet used for the core of this motor is Si
Great progress has been made with the addition of Al and Al (from a 1900 study by Barret et al., UK). 2. Description of the Related Art In recent years, non-oriented electrical steel sheets have been used in a great number of fields, from electric shavers and washing machines for daily necessities to huge generators in heavy industry. Among these, in particular, the required characteristics of non-oriented electrical steel sheets have been diversified, and not only reduction of conventional iron loss but also reduction of size and weight of electric equipment have been required. For this reason, the magnetic flux density is also an important characteristic.

[0003] For this reason, studies have been made on improving the texture of a steel sheet by adding various other elements in addition to the conventional Si and Al. For example, Japanese Patent Publication No. 40-16653 discloses a technique for containing As, Sn, Ni, Co, Cu, Mo, Cr and the like, but the special elements such as As and Co increase the cost. was there. In Japanese Patent Application Laid-Open No. 1-142050, Cr, Ni,
An embodiment containing a complex containing Sn, Sb, B and Cu is disclosed. However, the magnetic flux density was unsatisfactory because of the large amount of Al. Furthermore, Japanese Unexamined Patent Publication No. 7-268568 proposes a non-oriented electrical steel sheet containing Sn, Cu, Ni, Cr and V composites and having excellent surface properties. However, this also was unsatisfactory in magnetic flux density.

[0004]

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a technique for manufacturing a non-oriented electrical steel sheet having an excellent magnetic flux density for realizing a small and light motor or transformer. .

[0005]

In order to achieve the above object, the present invention has the following constitution. That is, in the present invention, (1) by weight%, C ≦ 0.01%, Si: 0.1-1.3%, Al: 0.001-0.006%, Mn <0.7%, P ≦ 0.2%, S ≦ 0.01%, N ≦ 0.005%, Sn: 0.001-0.1%, Cu: 0.01-0.4%, Ni: 0.01-0. 2%, Cr: 0.01 to 0.2%, non-oriented electrical steel sheet with excellent magnetic flux density, characterized by containing the balance of Fe and unavoidable components and having a magnetic flux density B50 of 1.77 T or more. It is. Also, (2) wt%, C ≦ 0.01%, Si: 0.1-1.3%, Al: 0.001-0.006%, Mn <0.7%, P ≦ 0.2 %, S ≦ 0.01%, N ≦ 0.005%, Sn: 0.001 to 0.1%, Cu: 0.01 to 0.4%, Ni: 0.01 to 0.2%, Cr : 0.01 to 0.2%, 800 in hot rolled sheet containing balance Fe and unavoidable components
~ 1100 ° C hot rolled sheet continuous annealing, then cold rolled,
This is a method for producing a non-oriented electrical steel sheet having excellent magnetic flux density characterized by annealing.

In particular, the present invention provides the following:
In a component system containing n, Ni, Cu, and Cr in a complex form, the content is low and the Al content is 0.001 to 0.00.
This is based on the finding that excellent magnetic flux density can be obtained only when the hot-rolled sheet annealing is performed at a high temperature in the range of 6%.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The amount of C is 0.01% or less. The reason for this limitation is that if the amount of C exceeds this, a problem of magnetic aging occurs.

[0008] The Si content is 0.1 to 1.3%. Si
It is known that increasing the amount improves iron loss but decreases magnetic flux density. If it is less than 0.1%, the iron loss is unsatisfactory, and if it exceeds 1.3%, the magnetic flux density deteriorates.
Limit to 0.1-1.3%.

[0009] The amount of Al is limited to 0.001 to 0.006%. If the amount of Al is less than 0.001%, the amount of oxides in the steel increases and the iron loss deteriorates, and the upper limit of 0.006% is that the magnetic flux density deteriorates. This is to avoid.

The Mn content is less than 0.7%. If the Mn content is 0.7% or more, the magnetic flux density becomes unsatisfactory, and this must be avoided.

[0011] The P content is 0.2% or less. P improves the rigidity of the steel sheet. However, if it exceeds 0.2%, solidification segregation is not possible and a brittleness problem in the cold occurs, which is not possible.

The amount of S is set to 0.01% or less. If the S content exceeds 0.01%, MnS precipitates increase and iron loss deteriorates, so it is necessary to avoid it.

The amount of N is limited to 0.005% or less.
If the content exceeds 0.005%, blister-like surface defects called blisters are generated.

The amount of Sn is 0.001 to 0.1%.
When the amount of Sn is increased, the magnetic flux density is improved, and the limit at which this effect can be obtained is 0.001%, and when it exceeds 0.1%, cracks occur on the surface of the steel sheet by hot rolling, resulting in flaws. So you have to avoid.

The Cu content is limited to 0.01% to 0.4%. When the amount of Cu is increased, the magnetic flux density is improved, and the limit at which this effect can be obtained is 0.01%, and when it exceeds 0.4%, cracks occur on the surface of the steel sheet in hot rolling and become flaws. So you have to avoid.

The amount of Ni is 0.01 to 0.2%. N
When the amount of i is increased, the magnetic flux density is improved, and the limit of obtaining this effect is 0.01%, and when it exceeds 0.2%, the problem of addition cost occurs.

The amount of Cr is 0.01-0.2%. C
When the amount of r is increased, the magnetic flux density is improved, and the limit at which this effect can be obtained is 0.01%, and when it exceeds 0.2%, there arises a problem of addition cost.

V, Ti, known as other harmful elements,
As for Nb, Zr, etc., the smaller the one, the better the iron loss is, and it is preferable that each of them is 0.01% or less. Furthermore, the present invention is not impaired even if Sb, Mo, Mg, and the like, which are known as texture improving elements, are contained up to 0.1%.

The slab heating during hot rolling is not particularly limited.
Good low temperature, 950-12 for the purpose of preventing fine precipitates
00 ° C. is preferred, and heating at this temperature is followed by normal hot rolling. Annealing is performed on the hot-rolled sheet by continuous annealing. In batch annealing, quality in the inside, inside, outside and in the width direction of the coil, especially the variation in magnetism is large, so it is better to avoid it. The hot-rolled sheet annealing temperature is 800 ° C. or higher. The higher the annealing temperature is, the higher the magnetic flux density is.
It is 0 ° C., and the high temperature limit is 1100 ° C. because the durability of the furnace and the effect of improving the magnetic flux density are saturated. Note that when the α → γ transformation is performed, the magnetic flux density may slightly decrease, but in some cases, annealing is preferably performed at a temperature in the ferrite region. Although the transformation temperature almost matches the Fe-Si phase diagram, the calculation phase diagram (CALPHAD) of the multi-dimensional system is strictly referred to. The soaking time may be about 10 to 180 seconds. The atmosphere is preferably ordinary non-oxidizing N ₂ or the like. .

Next, cold rolling is performed. The finish thickness should just be usual 0.15-0.8 mm. Then, after degreasing,
Perform finish annealing. Finish annealing temperature is 650 to 11
00 ° C. After this annealing, an organic, inorganic or mixture of two insulating films is applied and baked as before and shipped. Hereinafter, examples of the present invention will be described.

[0021]

EXAMPLES Example 1 A steel ingot containing various components was prepared by vacuum melting, hot-rolled at a heating temperature of 1000 ° C. and a finishing temperature of 830 ° C. to obtain a hot-rolled sheet having a thickness of 1.7 mm. Was. This hot-rolled sheet was subjected to annealing at 900 ° C. for 20 seconds in a nitrogen gas, air-cooled, pickled, and cold-rolled to obtain a cold-rolled sheet having a thickness of 0.50 mm. Subsequently, continuous annealing was carried out at 850 ° C. for 5 seconds in dry hydrogen. Next, an inorganic / organic mixed coating was applied and baked to form a 0.5 μm thick insulating film.
The magnetic properties were measured and averaged in the L and C directions of a 100 mm × 100 mm veneer sample. Table 1 shows the results.

[0022]

[Table 1]

The component conditions of the present invention, in particular, Sn, Cu, N
It can be seen that excellent magnetic properties can be obtained only for those containing four kinds of i and Cr in a composite and within the scope of the present invention.

Example 2 The composition was 0.0% by weight.
028% C, 0.7% Si, 0.1% Mn, 0.03%
P, 0.0003% S, 0.002% Al, 0.001
4% N, 0.014% Sn, 0.1% Cu, 0.02%
Ni, 0.05% Cr, 0.0001% Nb, 0.00
1% Ti, 0.0001% Sb, 0.002% V, 0.1%
Slab containing 01% Mo and 0.001% Mg is 1200
C. to obtain a hot-rolled sheet having a thickness of 3 mm. This was pickled and subjected to soaking at a temperature shown in Table 2 for 30 seconds with 5% H ₂ +95.
% N ₂ , cold-rolled to 0.35 mm, degreased, and annealed in hydrogen at 900 ° C. × 5 seconds, and measured for magnetism in the same manner as in Example 1. Note that the experiment No.
Was manufactured by omitting hot-rolled sheet annealing.

[0025]

[Table 2] As shown in Table 2, excellent magnetic flux density was obtained at the hot-rolled sheet annealing temperature within the range of the present invention. The 1040 ° C. hot-rolled sheet annealed material had a transformed structure as a result of light microscopic observation.

[0026]

As described above, the present invention provides a high magnetic flux density material contributing to downsizing of motors and small transformers in the electric industry and a method of manufacturing the same.

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 4K033 AA01 CA01 CA02 CA07 FA13 RA03 5E041 AA11 AA19 CA02 CA04 HB05 HB07 HB11 NN01 NN13 NN18

Claims (2)

[Claims] 1. wt%, C ≦ 0.01%, Si: 0.1-1.3%, Al: 0.001-0.006%, Mn <0.7%, P ≦ 0.2 %, S ≦ 0.01%, N ≦ 0.005%, Sn: 0.001 to 0.1%, Cu: 0.01 to 0.4%, Ni: 0.01 to 0.2%, Cr : A non-oriented electrical steel sheet having an excellent magnetic flux density, characterized in that the content is 0.01 to 0.2%, the balance contains Fe and unavoidable components, and the magnetic flux density B50 is 1.77 T or more. 2. In% by weight, C ≦ 0.01%, Si: 0.1-1.3%, Al: 0.001-0.006%, Mn <0.7%, P ≦ 0.2 %, S ≦ 0.01%, N ≦ 0.005%, Sn: 0.001 to 0.1%, Cu: 0.01 to 0.4%, Ni: 0.01 to 0.2%, Cr : Characterized in that the hot-rolled sheet containing 0.01 to 0.2% and containing the balance of Fe and unavoidable components is subjected to continuous hot-rolling annealing at 800 to 1100 ° C., followed by cold rolling and annealing. A method for manufacturing non-oriented electrical steel sheets with excellent magnetic flux density.