JPS62133041A - Soft magnetic material - Google Patents

Abstract

PURPOSE:To prevent deterioration in hot workability without deteriorating magnetic properties by adding specific amounts of one or more kinds among B, Zr, and REM or further Si to a low-carbon soft magnetic steel sheet improved in machinability by the addition of Bi. CONSTITUTION:As the soft magnetic steel sheet as magnetic material for electric motors, transformers, etc., 0.005-0.40%, by weight, Bi, for the purpose of improving machinability, and 1 or >=2 kinds among 0.0005-0.010% B, 0.005-0.20% Zr, and 0.005-0.20% REM are incorporated to a <0.10%-C soft steel sheet, or further <=5.0% Si is incorporated to the above. In this way, soft magnetic material free from deterioration in hot workability due to the addition of Bi for improving machinability, causing no problem of toxicity of Bi, and excellent in magnetic properties can be obtained.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) This invention can be applied, for example, to iron cores and yokes for relays.

Armatures, electromagnetic clutches, high frequency iron cores, electric motors.

It relates to soft magnetic materials used as electromagnetic materials such as transformers.

(Prior Art) Soft magnetic materials conventionally used for the purposes listed in L include, for example, electromagnetic soft iron bars (SUYB) specified in JIS C2503.

There is an electromagnetic soft iron plate (SUYP) specified in C2504. Such soft magnetic materials are required to have excellent magnetic properties such as coercive force and maximum permeability from the viewpoint of usage characteristics, but from the viewpoint of workability, hot bendability and toughness are required. In addition to the above, it is also required to be useful for machinability.

Therefore, in order to improve machinability, Pb was added to the magnetic pure iron material.
There were also some to which sulfur and sulfur were added.

(Problems to be Solved by the Invention) However, as mentioned above, when PB is added to improve the machinability of magnetic pure iron materials, it reduces the magnetic properties and is particularly difficult for food machinery. In the case of carbonaceous materials, problems with toxicity may arise, and when S is added, there is a problem in that the magnetic properties and hot workability are reduced at the same time.

Therefore, there was an idea to add an appropriate amount of Bi in order to improve machinability without deteriorating magnetic 2 properties, but there was a problem that adding Bi reduced hot workability. .

This invention was made by focusing on the above-mentioned conventional problems, and improves the machinability of soft magnetic materials such as magnetic pure iron materials without deteriorating their magnetic properties, and at the same time reduces hot workability. The purpose of the present invention is to provide a soft magnetic material that can prevent this.

[Structure of the invention] (F stage for solving problems) The soft magnetic material according to the present invention has a C: 0.1 in weight%.
0% or less, Bi: 0.005 to 0.40%, and B:
0.0005-0.010%.

Zr: 0.005 to 0.20%, REM: 0.
Contains one or two inserts 1- of 0.005 to 0.20%, and further contains Si: 5.0% or less as necessary, and the remainder is Fe and impurities, which improves magnetic properties and machinability. It is characterized by excellent hot workability and no toxicity problems.

Next, the reason for limiting the component range (weight %) of the soft magnetic material according to the present invention will be explained.

C: 0.10% or less C improves strength but reduces machinability, and from the viewpoint of magnetic properties such as coercive force and maximum permeability, it is desirable to have as little as possible, so the upper limit of C is o,
io% closed. Also.

It is more desirable that the amount of C+N is also 0.10% or less.

Bi: 0.005 to 0.40% Bi is known to be an element that improves the machinability of ordinary structural steel, along with PB, s, etc. Therefore, the inventor of the present invention has conducted intensive research on the properties uniquely required for soft magnetic materials, and has conducted various studies on the effects on magnetic properties and toxicity. As a result, Bi is an element that improves machinability without adversely affecting the magnetic properties of soft magnetic materials, and also has no toxicity problems like Pb, especially in food machinery where toxicity is a problem. It has been confirmed that this method can also be used in various applications. It was also confirmed that in order to obtain the effect of i, it is better to contain 0.005% or more. However, if the amount added is too large, it will have an adverse effect on hot workability and toughness, and will also cause problems in melting, so it was limited to 0.40% or less.

B: 0.0O05~0.010%, Zr: 0.005~
0.20%, REM: one or more of 0.005 to 0.20% B, Zr, and REM (one or more rare earth metals) are all hot-tempered by adding Bi. Since it is an effective element to improve the deterioration of workability,
One or more of these were included. Among these, B is an element that combines with O and N contained in steel to form oxides and nitrides, and is also effective in improving toughness, so when added, it should be at least 0.0005%. It's good. However, if it is too large, the hardness increases and machinability deteriorates, so it is preferably 0.010% or less. Also, Zr
It is an element that combines with O and N contained in steel to form oxides and nitrides, and is also effective in improving inertia, so when added, it is recommended to add it at 0.005% or more. However, if the amount is too high, machinability deteriorates, so it is preferable to set the content to 0.20% or more. moreover.

REM is an element that is effective in preventing the deterioration of hot workability due to the addition of Bi by forming a high melting point compound with Bi and preventing precipitation at the grain boundaries in the Bi medium, and this effect is It is also good to contain more than 0.005% to obtain. but.

If it is too large, it will impair ripening F properties, so it is best to keep it at 0.20% or less.

Si:5. Since Si is an element effective in improving the magnetic properties, it may be added as necessary. However, if the amount is too high, the toughness and hot workability will be reduced, so even if it is included, it is necessary to keep it at 5.0% or more.

In addition, it is not preferable to contain a large amount of Mn from the viewpoint of magnetic properties, but since it has the effect of improving strength, it is desirable to set the upper limit to 0.70%, and P contains 0.70% from the viewpoint of corrosion resistance and hot workability. Therefore, it is desirable to set the L limit to 0.05%, and although S improves machinability, it is desirable to set the upper limit to 0.04% from the viewpoint of corrosion resistance and hot workability. It is desirable that the content be 0.020% or less because it increases the amount of inclusions in the material, reduces hot-meltability, and impairs strength and toughness as well as magnetic properties.

(Example) A soft magnetic material having the components shown in Table 1 was melted, then cast, and hot forged to create round bars with a diameter of 60 mm. At the same time, a ring-shaped magnetic property test piece with an outer diameter of 45 mm, an inner diameter of 33 mm, and a thickness of 10 mm was also fabricated.

Next, as a machinability evaluation test, longitudinal turning was performed under the conditions shown in Table 2, and the machinability of each sample material was evaluated as 1:f.

The results are shown in Table 1.

Table 2 Also, as a magnetic property evaluation test, the coercive force was determined as ΔIII using the above magnetic property test piece. The results are also shown in Table 1.

Furthermore, when the hot workability of each sample material was evaluated, the results were also shown in Table 1.

As shown in Table 751, the soft magnetic material according to the present invention has excellent magnetic properties, excellent machinability, and excellent hot workability. It was confirmed that there was no problem with IU properties. Therefore, when used as a material for regular electromagnetic valve cores, relay cores, electromagnetic clutches, and electromagnetic parts for electric motor shades, it has excellent processability into the parts.
It has been confirmed that it has excellent magnetic properties and is suitable for parts for food machinery, etc., which are required to be non-toxic.

[Effects of the Invention] As explained above, the soft magnetic material according to the present invention has C: 0.10% or less and Bi: 0.005% by weight.
~0.40%, and B:0,0005~0,01
・0%, Zr: 0.005-0.20%, REM: 0
．． 005 to 0.20%, and optionally contains 5.0% or less of Si, with the remainder being F.
Since it consists of E and impurities, it has excellent magnetic properties and machinability, and there is no deterioration in hot workability due to the addition of Bi to improve machinability. It is suitable as a material for electromagnetic parts, such as iron cores for relays, yokes, armatures, electromagnetic clutches, and electric motors, because it has no problems with cIi properties and has good magnetic properties. It has the advantage of being suitable as an electromagnetic material for food machinery, which requires not only the ability to process materials efficiently and with high precision, but also to be particularly free of malignant properties.

Claims (2)

[Claims] (1) In weight%, C: 0.10% or less, Bi: 0.005 to 0.40%, and B: 0.000
5-0.010%, Zr: 0.005-0.20%, R
EM: A soft magnetic material characterized by containing one or more of 0.005 to 0.20%, with the balance consisting of Fe and impurities. (2) In weight%, C: 0.10% or less, Si: 5.0%
Below, Bi: 0.005 to 0.40%, and B: 0.
0005-0.010%, Zr: 0.005-0.20
%, REM: 0.005 to 0.20%, and the remainder is Fe and impurities.