JPH02301544A - Soft-magnetic alloy with high electric resistance for cold forging - Google Patents

Abstract

PURPOSE:To obtain a high electric resistance soft-magnetic alloy for cold forging excellent in magnetic properties and electric resistance by combinedly adding specific amounts of Al and Cr to an Fe-Ni soft-magnetic alloy and also reducing respective contents of C and N. CONSTITUTION:The above soft-magnetic alloy is prepared by incorporating <2%, by weight, Al and <6% Cr as essential components to an Fe-Ni soft- magnetic alloy containing 33-39.5% Ni and also limiting respective contents of C and N as impurities so that their total content is regulated to <=0.02%, or further, <5% Mn or <15% Cu and/or <10% Co, or further, one or >=2 kinds among 0.03-0.40% Pb, 0.01-0.60% Ce, 0.01-0.10% Se, 0.01-0.40% Te, 0.03-0.40% Bi, 0.0010-0.0100% Ca, and 0.01-0.25% Sn are added and incorporated to the above alloy independently or in combination. By this method, the soft- magnetic alloy which has superior cold forgeability as well as excellent electric resistance and magnetic properties and in which tensile strength is reduced as low as <=50kgf/mm<2> can be obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to magnetic properties used in electronic fuel injection devices, solenoid valves, magnetic sensors, magnetic shielding materials, high frequency transformers, etc.
This invention relates to a high electrical resistance soft magnetic alloy for cold forging with excellent electrical resistance.

[Prior art] Magnetic core materials developed in recent years, such as electronic fuel injection devices, solenoid valves, and magnetic sensors, have high electrical resistance and excellent magnetic properties to improve responsiveness, as well as to reduce costs. Excellent cold forging properties are essential.

For these soft magnetic alloys, iron-nickel permalloy is used. Conventionally, 45Ni-Fe alloy among permalloys has been used as the magnetic core material of these devices. However, this 45Ni-Fe alloy
Although it had excellent magnetic properties and cold forgeability, it had poor electrical resistance.

[Problem to be solved by the invention] However, in recent years, soft magnetic alloys have been developed that have low tensile strength, excellent cold forgeability, can reduce processing costs, have high electrical resistance, and have excellent responsiveness. It has become required. Therefore, in response to these needs, 43Ni 3Si
Fe alloy and 45Ni-3M.

Alloys with improved electrical resistance, such as -Fe alloys, have emerged.

However, although these alloys have excellent electrical resistance and magnetic properties, they have poor cold forgeability, and none of them simultaneously satisfy all three requirements of magnetic properties, electrical resistance, and cold forgeability. .

The present invention was made to solve the above-mentioned drawbacks of conventional materials used as magnetic core materials for electronic fuel injection devices, etc., and is required for magnetic core materials for electronic fuel injection devices, solenoid valves, magnetic sensors, etc. It shows excellent electrical resistance with an electrical resistance of 80 μΩe1m or more, and a tensile strength of 50 kgf/a.
The object of the present invention is to provide a high electrical resistance soft magnetic alloy for cold forging which has a magnetic property of less than m'', excellent cold forgeability, and a saturation magnetic flux density of 10,000 or more.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the inventors have conducted intensive research on the influence of additive elements on iron-nickel based soft magnetic alloys. As a result, it was discovered that Al had the highest rate of increase in electrical resistance per 1% among various alloying elements. However, on the other hand, it has been found that addition of Al increases tensile strength and inhibits cold forgeability, so it has been found that a large amount cannot be added.

Therefore, the inventors conducted extensive research on the third additive element, and although it was previously thought that increasing electrical resistance and decreasing tensile strength are contradictory properties, they discovered the following completely unexpected findings: I got it. It was found that Cr increases electrical resistance while decreasing tensile strength. And Al and Cr
Through the combined addition of , we have completed an alloy of the present invention that satisfies both high electrical resistance and cold forgeability while maintaining magnetic properties.

The high electrical resistance soft magnetic alloy for cold forging of the present invention has the following features in terms of weight ratio: Ni: 33 to 39.5%, Al: 2% or less, Cr: 6% or less, C+N: 0.02% or less. Contains
The gist is that the remainder consists of Fe and impurity elements.

The second invention is the first invention with the addition of 5% or less Mn, which improves electrical resistance and cold forgeability similarly to Cr, and the third invention is the addition of Cu, which improves the saturation magnetic flux density, to the first invention; 15
% or less and Co: 10% or less. The fourth invention is the fifteenth!
Specifically, Mn is 5% or less, Cu is 15% or less, and Co is 1
The gist is that 0% or less of one or 2M of these is contained.

The fifth to eighth inventions each contain Pb, 0.03 to 0.40%, and Ce; 0 to improve the machinability of the first to fourth inventions.
, 01-0.60%, Se; 0.01-0.10%,
Te; 0.01-0.40%, Bi; 0.03-04
0%, Ca; 0.0010-0.0100% and Sn
; The gist is that one or more of 0.01 to 0.25% is contained.

[Function] In the present invention, in permalloy, which is an iron-nickel based soft magnetic alloy, 2% or less of Al is added while reducing the amount of Ni added, so that the electrical resistance can be increased while maintaining the magnetic properties. Furthermore, since 6% or less of Cr is added together with Al, the increase in tensile strength due to the addition of Al can be suppressed, and the electrical resistance can be further increased.

Next, the reason for limiting the components of the high electrical resistance soft magnetic alloy for cold forging of the present invention will be explained.

Ni: 33 to 39.5% When Ni is in a binary alloy with Fe within the above range, good coercive force, high magnetic permeability, saturation magnetic flux density, and religiously high electrical resistance can be obtained. In order to obtain the above effect, it is necessary to add 33% or more, and if the amount added is less than 33%, the saturation magnetic flux density will drop sharply, resulting in insufficient properties, and soft magnetic properties such as coercive force and magnetic permeability will also drop sharply. do. However, Ni is 3
If the content exceeds 9.5%3, the electrical resistance will decrease and the cost will increase, so the upper limit was set at 39.5%.

Al: 2% or less Al is the most important element in the alloy of the present invention, and has the characteristic of having the greatest increase in electrical resistance per unit weight. However, when added in excess of 2%, it increases the tensile strength. Since it impairs cold forging properties, the upper limit was set at 2%.

Cr; 6% or less Cr is one of the elements with the greatest characteristics in the present invention,
It has the effect of lowering tensile strength while increasing electrical resistance, an effect that did not previously exist. However, if the content exceeds 6%, the saturation magnetic flux density decreases significantly, so the upper limit is set to 6%.
%.

C+N: 0.02% or less Both C and N reduce cold forgeability and magnetic properties due to solid solution strengthening, so it is better to reduce them as much as possible, but if C+N exceeds 0.02%, coercive force and magnetic permeability will decrease. The upper limit was set at 0.02% because the soft magnetic properties of carbon and the like sharply decrease, leading to an increase in tensile strength.

Mn: 5% or less Similar to Cr, Mn has the effect of increasing electrical resistance while decreasing tensile strength. Although this effect is slightly inferior to that of Cr, there is a cost advantage by adding it in combination with Cr. However, if more than 5% is added, the saturation magnetic flux density will drop significantly, so the upper limit was set at 5%.

Cu: 15% or less By adding Cu, the saturation magnetic flux density can be increased. However, if the amount added exceeds 15%, hot workability deteriorates, so the upper limit was set at 15%.

Co: 10% or less Co is an element that can improve the saturation magnetic flux density of the alloy. However, if the amount added exceeds 10%, the cost increases and is not economical, so the upper limit was set at 10%.

Pb, 0.03-0.40%, Ce; 0.01-0.6
0%, Se; 0.01~0.10%, Te; 0.01~
040%, Bi; 0.03-0.40%, Ca; 0.0
010~0.0100%, Sn; Olo 1~
Since the 025% Fe Ni alloy is soft and has high toughness, the cutting process is extremely poor, and the temperature of the cutting edge during cutting becomes extremely high, resulting in a decrease in tool head strength.

By adding appropriate amounts of the above elements, machinability is improved without deteriorating magnetic properties and hot workability. The reason for limiting the lower limit of these additive elements is that if they are not added beyond this, the above effects cannot be obtained and the chip disposability will not be significantly improved. Further, the reason for limiting the upper limit is that adding more than this lowers the magnetic properties and hot workability.

[Example] Next, the characteristics of the alloy of the present invention will be clarified by comparing it with a conventional example and a comparative example. Table 1 shows the chemical composition of these test materials.

In Table 1, No. 1 to 12 are the first invention, and No. 1 is the first invention.
3 to 14 are the second invention, No. 15 to 17 are the third invention, N
o, 18 to 21 are the fourth invention, No. 22 to 33 are the fifth invention, No. 34 to 37 are the sixth invention, No. 38 to 42 are the seventh invention, No. 43 to 47 are the eighth invention . Further, Nos. 48 to 51 are comparative examples, and No. 48 is N
1 Comparative example with high content, No. 49 is a comparative example with low Ni content, No. 50 is a comparative example with high C+N%, No. 5
No. 1 is a comparative example with a high Cr content. No, 52-54
is a conventional example, No. 52 is 4'5Ni, No. 5
3 is 43Ni-3Si-Fe, No, 54 is 47Ni-
3M.

-Fe.

(Margin below) The test materials in Table 1 were held at 1100°C for 2 hours,
Then, a heat treatment called furnace cooling was performed, and the saturation magnetic flux density, electrical resistance, tensile strength, and machinability were measured.

Regarding the magnetic properties, a ring with an outer diameter of 24 φ, an inner diameter of 16 φ, and a thickness of 16 mm was prepared as a test piece using a DC type BH tracer, and the saturation magnetic flux density was measured.

For electrical resistance, use the hobby stone bridge method.
Measurements were made using a 1.2φ x 500g line as a test piece. Moreover, the tensile strength was measured using a JIS No. 4 test piece.

Rigidity was determined based on chip disposability, and the test was carried out for typical examples for the first to fourth inventions and for the fifth to eighth inventions. In order to judge the chip disposability, using cemented carbide tool steel, the cutting speed was kept constant, the feed was changed to three levels, and the depth of cut was set to three levels, chips were collected, and the shape of the chips was observed.

Out of 9 levels, cases where curled chips with good cutting properties were obtained at level 6 or higher were evaluated as ◯, and cases where level 5 or lower were evaluated as ×.

The measured saturation magnetic flux density, electrical resistance, tensile strength, and rigidity are also shown in Table 1.

As is known from Table 1, Comparative Example No. 48, which has a high N1 content, has a low electrical resistance of 74.2 μΩe1m, and Comparative Example No. 49, which has a low Ni content, has a low saturation magnetic flux density of 2220 G. . In addition, the comparison PA No. 50, which had a high C+N content, had a saturated magnetic flux density of 9800 G and a tensile strength of 53.8 kgf/Yakane 2, which was inferior in magnetic properties and cold forgeability, and a comparison with a high Cr content. Example No. 51 has a saturation magnetic flux density of 8920G
However, its magnetic properties are inferior.

Regarding conventional examples, No. 52 has excellent magnetic properties and cold forging properties, but has low electrical resistance;
Although No. 53, No. 54, and No. 54 have good magnetic properties and electrical resistance, they have high tensile strength and poor cold forging properties.

Compared to these comparative examples and conventional examples, the present invention example N
o, 1 to 47, the amount of CfN is regulated and appropriate amounts of Al and Cr are used.
Due to the combined addition of
f/am2 or less, and was confirmed to have excellent electrical properties and cold forgeability. Furthermore, regarding the stiffness, the chip disposability of the first to fourth inventions is ×, while the chip disposability of the fifth to eighth inventions is ○, and It has been confirmed that the rigidity can be significantly improved by the addition of an iron-nickel based soft magnetic alloy. In the alloy, C+Nl
By adding 3!1t of Al and Cr in combination, we succeeded in increasing the electrical resistance and reducing the tensile strength without reducing the magnetic ↑ resistance.

As a result, the present invention has been able to obtain a soft magnetic alloy that maintains magnetic properties and has excellent cold forgeability in addition to electrical properties. It is extremely useful for materials, high frequency transformers, etc.

Claims (8)

[Claims] (1) Contains Ni: 33 to 39.5%, Al: 2% or less, Cr: 6% or less, C+N: 0.02% or less, and the remainder consists of Fe and impurity elements. High electrical resistance soft magnetic material for cold forging. (2) Weight ratio: Ni: 33-39.5%, Al: 2% or less, Cr: 6% or less, C+N: 0.02% or less, Mn;
A high electrical resistance soft magnetic alloy for cold forging, characterized in that it contains 5% or less of Fe, and the remainder consists of Fe and impurity elements. (3) Contains Ni: 33 to 39.5%, Al: 2% or less, Cr: 6% or less, C+N: 0.02% or less, and further Cu: 15% or less and Co: 10% or less A high electrical resistance soft magnetic alloy for cold forging, characterized in that it contains one or two of these, with the remainder consisting of Fe and impurity elements. (4) Weight ratio: Ni: 33-39.5%, Al: 2% or less, Cr: 6% or less, C+N: 0.02% or less, Mn;
5% or less, Cu; 15% or less and Co; 10% or less, and the remainder is Fe and impurity elements. (5) Contains Ni: 33 to 39.5%, Al: 2% or less, Cr: 6% or less, C+N: 0.02% or less, and further Pb: 0.03 to 0.40% by weight. Ce; 0.01
~0.60%, Se; 0.01~0.10%, Te; 0
．． 01-0.40%, Bi; 0.03-0.40%, C
a; 0.0010-0.0100% and Sn; 0.0
A high electrical resistance soft magnetic alloy for cold forging, characterized in that it contains one or more of 1 to 0.25% of Fe and the remainder consists of Fe and impurity elements. (6) Weight ratio: Ni: 33-39.5%, Al: 2% or less, Cr: 6% or less, C+N: 0.02% or less, Mn;
Contains 5% or less, and further contains Pb; 0.03 to 0.40%
, Ce; 0.01-0.60%, Se; 0.01-0.
10%, Te; 0.01-0.40%, Bi; 0.03
~0.40%, Ca; 0.0010 to 0.0100%, and Sn; 0.01 to 0.25%, and the remainder is Fe and impurity elements. High electrical resistance soft magnetic alloy for cold forging. (7) Weight ratio of Ni: 33 to 39.5%, Al: 2% or less, Cr: 6% or less, C+N: 0.02% or less, and Cu
15% or less and Co; contains one or two of 10% or less, and further contains Pb; 0.03 to 0.40%, C
e; 0.01-0.60%, Se; 0.01-0.10
%, Te; 0.01-0.40%, Bi; 0.03-0
．． 40%, Ca; 0.0010 to 0.0100%, and Sn; 0.01 to 0.25%. High electrical resistance soft magnetic alloy for forging. (8) Weight ratio: Ni: 33-39.5%, Al: 2% or less, Cr: 6% or less, C+N: 0.02% or less, Mn;
5% or less, one or two of Cu; 15% or less and Co; 10% or less, and further Pb; 0.03
~0.40%, Ce; 0.01~0.60%, Se; 0
．． 01-0.10%, Te; 0.01-0.40%, B
i; 0.03-0.40%, Ca; 0.0010-0.
A high electrical resistance soft magnetic alloy for cold forging, characterized in that it contains one or more of Sn; 0.01 to 0.25%, and the remainder consists of Fe and impurity elements.