JP2011137188A - Soft magnetic steel component superior in magnetic property by alternating current, and method for manufacturing the same - Google Patents
Soft magnetic steel component superior in magnetic property by alternating current, and method for manufacturing the same Download PDFInfo
- Publication number
- JP2011137188A JP2011137188A JP2009295985A JP2009295985A JP2011137188A JP 2011137188 A JP2011137188 A JP 2011137188A JP 2009295985 A JP2009295985 A JP 2009295985A JP 2009295985 A JP2009295985 A JP 2009295985A JP 2011137188 A JP2011137188 A JP 2011137188A
- Authority
- JP
- Japan
- Prior art keywords
- less
- soft magnetic
- steel
- magnetic steel
- diffusion layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
- Soft Magnetic Materials (AREA)
Abstract
Description
本発明は、軟磁性鋼部品およびその製造方法に関し、詳細には、交流磁界で用いられる軟磁性鋼部品およびその製造方法に関するものである。 The present invention relates to a soft magnetic steel part and a method for manufacturing the same, and more particularly to a soft magnetic steel part used in an alternating magnetic field and a method for manufacturing the same.
軟磁性鋼部品は、例えば、自動車や産業機械などに用いられる交流磁界で駆動するモータの磁気回路を構成する部品（例えば、コア材）として使用されている。この軟磁性鋼部品は、従来では、複数の電磁鋼板を積層した積層体を打ち抜き加工等により加工して成形して製造していた。しかしこうして得られた軟磁性鋼部品は、複数の電磁鋼板が積層されているため、強度や剛性が低かった。また、複数の電磁鋼板を積層する必要があるため、製造コストが高かった。 Soft magnetic steel parts are used, for example, as parts (for example, core materials) constituting a magnetic circuit of a motor driven by an alternating magnetic field used in automobiles, industrial machines, and the like. Conventionally, this soft magnetic steel part has been manufactured by processing a laminated body obtained by laminating a plurality of electromagnetic steel sheets by stamping or the like. However, the soft magnetic steel parts obtained in this manner have low strength and rigidity because a plurality of electromagnetic steel sheets are laminated. Moreover, since it was necessary to laminate | stack several electromagnetic steel plates, the manufacturing cost was high.
近年では、条鋼（例えば、棒鋼や線材）から軟磁性鋼部品を製造することが検討されている。軟磁性鋼部品の素材として条鋼を用いれば、冷間鍛造により部品形状に成形できるため、上述したように電磁鋼板同士を積層する工程を省略でき、製造コストを低減できる。また、条鋼を用いた場合には、積層構造ではないため、強度や剛性を高めることができる。 In recent years, it has been studied to produce soft magnetic steel parts from steel bars (for example, steel bars and wire rods). If strip steel is used as the material of the soft magnetic steel part, it can be formed into a part shape by cold forging, so that the step of laminating electromagnetic steel sheets can be omitted as described above, and the manufacturing cost can be reduced. Further, when the steel bar is used, since it is not a laminated structure, strength and rigidity can be increased.
上記軟磁性鋼部品には、交流磁気特性が良好であることが求められる。具体的には、交流磁界中で使用したときの鉄損の低減が求められる。鉄損は、ヒステリシス損と渦電流損との合計であるが、交流磁界中では渦電流損が鉄損の大半を占める。この渦電流損を低減するには、鋼の電気抵抗を高めることが有効である。 The soft magnetic steel parts are required to have good AC magnetic characteristics. Specifically, reduction of iron loss when used in an alternating magnetic field is required. Iron loss is the sum of hysteresis loss and eddy current loss, but eddy current loss accounts for the majority of iron loss in an alternating magnetic field. In order to reduce this eddy current loss, it is effective to increase the electrical resistance of steel.
電気抵抗率を高め、交流磁気特性を改善した軟磁性材料が特許文献１に提案されている。この文献には、軟磁性材料の電気抵抗を４０μΩｃｍ以上に高めるために、「２×（Ａｌ％＋Ｓｉ％）＋Ｃｒ％」の関係式によって算出されるＳ値を４．５〜９の範囲に調整することが開示されている。 Patent Document 1 proposes a soft magnetic material with improved electrical resistivity and improved AC magnetic characteristics. In this document, in order to increase the electric resistance of the soft magnetic material to 40 μΩcm or more, the S value calculated by the relational expression “2 × (Al% + Si%) + Cr%” is adjusted to the range of 4.5-9. Is disclosed.
ところで条鋼には、部品形状に成形するために冷間鍛造性が良好であることも求められる。冷間鍛造性としては、変形抵抗が低く、変形能が高いことが必要である。変形抵抗を低くすることで、鍛造時の荷重を低減できるため、冷間鍛造で使用する金型の寿命を向上させることができる。また、変形能が高く、冷間鍛造しても割れが発生し難くすることで、軟磁性鋼部品を小型化したり、部品形状を複雑化できる。 By the way, the steel bar is also required to have good cold forgeability in order to be formed into a part shape. The cold forgeability needs to have low deformation resistance and high deformability. Since the load at the time of forging can be reduced by lowering the deformation resistance, the life of the mold used for cold forging can be improved. In addition, since the deformability is high and cracking hardly occurs even when cold forging, it is possible to reduce the size of the soft magnetic steel part and to complicate the part shape.
交流磁気特性と高い変形能を有し、且つ変形抵抗が小さい軟磁性鋼材が特許文献２に提案されている。この文献には、交流磁気特性と変形能を改善するには、Ｓｉ、Ｍｎ、Ａｌ、Ｃ、Ｎ、Ｓ、Ｐの含有量を最適化すればよいこと、また交流磁気特性と変形能を一層向上させ、かつ変形抵抗を改善するには、Ｔｉを含有させれば良いことが開示されている。また、交流磁気特性を改善するには、鋼の電気抵抗を高める効果のあるＳｉ、Ｍｎ、Ａｌの固溶量を高くし、渦電流損を小さくすればよいことが記載されている。 Patent Document 2 proposes a soft magnetic steel material having alternating magnetic properties and high deformability and low deformation resistance. In this document, in order to improve AC magnetic properties and deformability, it is only necessary to optimize the contents of Si, Mn, Al, C, N, S, and P, and to further improve AC magnetic properties and deformability. It is disclosed that Ti may be contained in order to improve and improve deformation resistance. Further, it is described that in order to improve the AC magnetic characteristics, the solid solution amount of Si, Mn, and Al, which has the effect of increasing the electrical resistance of steel, should be increased to reduce the eddy current loss.
また、特許文献３には、電気抵抗が高く、優れた高速応答性を有し、且つ量産可能にして製品コストの低減化を図り得る電磁弁用磁気回路部材が開示されている。この文献には、磁気回路部材の母材として電磁軟鉄あるいは低炭素鋼を用いることで切削加工性および冷間鍛造性を改善できること、磁気回路部材中にＡｌを含有させることにより電気抵抗が高くなり、渦電流損を低減できることが記載されている。磁気回路部材中にＡｌを含有させる方法としては、Ａｌ粉末とＡｌ2Ｏ3粉末の混合粉にＮＨ4Ｃｌを加えたものの中に電磁軟鉄製の磁気回路部材を埋め込み、水素気流中で９００℃、３時間の加熱処理を施す方法を採用している。 Patent Document 3 discloses a magnetic circuit member for an electromagnetic valve that has high electrical resistance, has excellent high-speed response, can be mass-produced, and can reduce product cost. In this document, it is possible to improve the machinability and cold forgeability by using electromagnetic soft iron or low carbon steel as the base material of the magnetic circuit member, and the electrical resistance is increased by containing Al in the magnetic circuit member. It is described that eddy current loss can be reduced. As a method for incorporating Al in the magnetic circuit member, a magnetic circuit member made of electromagnetic soft iron is embedded in a mixture of Al powder and Al 2 O 3 powder and NH 4 Cl added, and 900 ° C. in a hydrogen stream. A method of performing a heat treatment for 3 hours is adopted.
上記特許文献１には、軟磁性材料の電気抵抗を高め、交流磁気特性を改善することについて記載されているが、軟磁性材料の冷間鍛造性を改善すること（特に、変形抵抗を小さく、変形能を良好にすること）については全く着目されていない。 The above-mentioned Patent Document 1 describes increasing the electric resistance of a soft magnetic material and improving AC magnetic characteristics, but improving the cold forgeability of the soft magnetic material (particularly, reducing the deformation resistance, No attention has been paid to improving the deformability.
一方、上記特許文献２、３には、交流磁気特性と冷間鍛造性を兼ね備えた軟磁性鋼材について記載されている。これらのうち特許文献２に開示されている軟磁性鋼材はＴｉを必須元素として含有するものであり、Ｔｉを含有させた場合には、鋼材中にＴｉＣやＴｉＮなどの析出物を形成し、結晶粒を微細化して交流磁気特性を低下させるという問題が生じる。そこで本発明者は、Ｔｉを含有しない成分系の鋼材について検討した。また、特許文献３に開示されているように、混合粉末中に磁気回路部材を埋め込んで磁気回路部材の表面にＡｌを拡散浸透させる方法では、混合粉末の適正な調整および充填が困難なため、Ａｌ拡散にムラが生じやすい。また、部材表面にＡｌが濃化し過ぎるとＦｅＡｌなどの非磁性相が形成され、交流磁気特性を改善できなかった。また、混合粉末中に磁気回路部材を埋め込んでＡｌを拡散浸透させる方法では、連続操業し難く、生産性を高めることが難しい。 On the other hand, Patent Documents 2 and 3 describe soft magnetic steel materials having both AC magnetic characteristics and cold forgeability. Among these, the soft magnetic steel material disclosed in Patent Document 2 contains Ti as an essential element. When Ti is contained, precipitates such as TiC and TiN are formed in the steel material, and crystal There arises a problem that the magnetic properties are reduced by reducing the size of the grains. Therefore, the present inventor has studied a component steel material not containing Ti. Further, as disclosed in Patent Document 3, in the method of embedding a magnetic circuit member in the mixed powder and diffusing and infiltrating Al into the surface of the magnetic circuit member, it is difficult to properly adjust and fill the mixed powder. Unevenness is likely to occur in Al diffusion. Further, when Al is excessively concentrated on the surface of the member, a nonmagnetic phase such as FeAl is formed, and the AC magnetic characteristics cannot be improved. Further, in the method of embedding the magnetic circuit member in the mixed powder and diffusing and penetrating Al, it is difficult to continuously operate and it is difficult to improve productivity.
本発明は上記の様な事情に着目してなされたものであって、その目的は、交流磁気特性に優れており、しかも部品形状に成形するときの冷間鍛造性が良好な軟磁性鋼部品およびその製造方法を提供することにある。 The present invention has been made by paying attention to the above-mentioned circumstances, and the purpose thereof is a soft magnetic steel part having excellent AC magnetic characteristics and good cold forgeability when formed into a part shape. And providing a manufacturing method thereof.
上記課題を解決することのできた本発明に係る軟磁性鋼部品とは、化学成分組成が、Ｃ：０．００２〜０．２０％（質量％の意味。以下同じ。）、Ｓｉ：１．２％以下（０％を含まない）、Ｍｎ：０．０５〜２．６％、Ｐ：０．０５％以下（０％を含まない）、Ｓ：０．０５％以下（０％を含まない）、Ｃｒ：４％以下（０％を含まない）、Ａｌ：０．００２〜２．２％、Ｎ：０．０１％以下（０％を含まない）、Ｏ：０．０３％以下（０％を含まない）、残部：鉄および不可避不純物で、且つ下記式（１）を満足するものであり、表層部に、１〜１３質量％のＡｌを含有し、且つ最表面側から中心部に向かってＡｌ量が減少するＡｌ拡散層が形成された軟磁性鋼部品であり、前記軟磁性鋼部品の最表面から５μｍ深さにおける最大Ａｌ濃度が１８質量％以下（０質量％を含まない）で、前記Ａｌ拡散層の厚みが４０μｍ以上である点に要旨を有している。下記式（１）中、［ ］は、各元素の含有量を示している。
１３×［Ｃ］＋２×［Ｓｉ］＋［Ｍｎ］＋［Ｃｒ］／５＋［Ａｌ］≦２．８ ・・・（１）
The soft magnetic steel part according to the present invention that has solved the above problems has a chemical composition of C: 0.002 to 0.20% (meaning mass%, the same shall apply hereinafter), Si: 1.2. % Or less (not including 0%), Mn: 0.05 to 2.6%, P: 0.05% or less (not including 0%), S: 0.05% or less (not including 0%) Cr: 4% or less (excluding 0%), Al: 0.002 to 2.2%, N: 0.01% or less (not including 0%), O: 0.03% or less (0% The remainder: iron and inevitable impurities and satisfying the following formula (1), the surface layer portion contains 1 to 13% by mass of Al, and from the outermost surface side toward the center portion. Soft magnetic steel part formed with an Al diffusion layer in which the amount of Al decreases, and the maximum Al concentration at a depth of 5 μm from the outermost surface of the soft magnetic steel part 18 wt% or less (excluding 0 mass%), the thickness of the Al diffusion layer has a gist in that at 40μm or more. In the following formula (1), [] indicates the content of each element.
13 × [C] + 2 × [Si] + [Mn] + [Cr] / 5 + [Al] ≦ 2.8 (1)
上記軟磁性鋼部品は、最表面から５μｍ深さにおけるＡｌ濃度を複数箇所測定したときに、最大値（Ａｌmax）と最小値（Ａｌmin）の比（Ａｌmax／Ａｌmin）が２以下（０を含まない）で、バラツキが少ないことが好ましい。また、前記Ａｌ拡散層の厚みは、１００μｍ以上であることが好ましい。 The soft magnetic steel part has a maximum value (Al max ) and minimum value (Al min ) ratio (Al max / Al min ) of 2 or less when a plurality of Al concentrations at a depth of 5 μm from the outermost surface are measured. 0 is not included), and it is preferable that there is little variation. The thickness of the Al diffusion layer is preferably 100 μm or more.
本発明の軟磁性鋼部品は、表面にＡｌ皮膜を有し、部品形状に加工された鋼材を８５０℃以上で１時間以上加熱することによって製造できる。 The soft magnetic steel part of the present invention can be produced by heating a steel material having an Al film on the surface and processed into a part shape at 850 ° C. or more for 1 hour or more.
本発明によれば、軟磁性鋼部品の最表面から５μｍ深さ位置にＡｌが所定値以上に濃化するのを防止しつつ、軟磁性鋼部品の表層部に１〜１３質量％のＡｌを含有し、且つ最表面側から中心部に向かってＡｌ量が減少するＡｌ拡散層を形成しているため、表層部の電気抵抗を高めることができ、渦電流損を低減できる結果、交流磁気特性を改善できる。また、上記軟磁性鋼部品の素材となる鋼材に合金元素として含有させるＣ、Ｓｉ、Ｍｎ、ＣｒおよびＡｌ量の関係を適切に調整しているため、鋼材の変形抵抗を小さく、変形能を良好にできるため、部品形状に成形するときの冷間鍛造性を改善できる。 According to the present invention, 1 to 13% by mass of Al is added to the surface layer portion of the soft magnetic steel part while preventing Al from being concentrated to a predetermined value or more at a depth of 5 μm from the outermost surface of the soft magnetic steel part. Containing and forming an Al diffusion layer in which the amount of Al decreases from the outermost surface side toward the center, the electrical resistance of the surface layer can be increased and eddy current loss can be reduced, resulting in AC magnetic characteristics Can be improved. In addition, since the relationship between the amount of C, Si, Mn, Cr and Al contained in the steel material as the material of the soft magnetic steel part is appropriately adjusted, the deformation resistance of the steel material is small and the deformability is good. Therefore, the cold forgeability when forming into a part shape can be improved.
本発明者は、軟磁性鋼部品の交流磁気特性を高めると共に、部品形状に成形するときの冷間鍛造性を改善することを目指して鋭意検討を重ねてきた。 The present inventor has intensively studied with the aim of improving the AC magnetic characteristics of soft magnetic steel parts and improving the cold forgeability when forming into a part shape.
軟磁性鋼材の交流磁気特性を改善するには、表層部における電気抵抗を高め、渦電流損を低減する必要がある。表層部における電気抵抗を高める手段としては、上記特許文献３で提案されているように、部材の表面にＡｌを含浸させる方法が知られている。しかし本発明者がこの文献に開示されている粉末塗布法について検討したところ、Ａｌを含浸させるためにＡｌ粉末を用いた場合には、部材表面に含浸されるＡｌ量にバラツキが生じ、局所的にＡｌが濃化し過ぎる現象が認められた。Ａｌ濃度が高くなり過ぎるとＦｅＡｌなどの非磁性相を形成し、交流磁気特性を劣化させる原因になることが分かった。 In order to improve the AC magnetic characteristics of the soft magnetic steel material, it is necessary to increase the electrical resistance in the surface layer portion and reduce the eddy current loss. As a means for increasing the electrical resistance in the surface layer portion, a method of impregnating Al on the surface of a member is known as proposed in Patent Document 3 above. However, when the present inventor examined the powder coating method disclosed in this document, when Al powder was used to impregnate Al, the amount of Al impregnated on the surface of the member varied, resulting in locality. A phenomenon in which Al was excessively concentrated was observed. It has been found that if the Al concentration becomes too high, a non-magnetic phase such as FeAl is formed, and the AC magnetic characteristics are deteriorated.
そこで本発明者は、上記特許文献３に開示された粉末塗布法とは異なる方法で、軟磁性部品の表層部にＡｌを含浸させることについて検討を重ねた。その結果、表面にＡｌ皮膜を有し、且つ部品形状に加工された鋼材に熱処理を施すと、表面に存在するＡｌが鋼材内部へ均一に拡散浸透し、Ａｌ拡散層を形成すること、このＡｌ拡散層は、表層部の電気抵抗を高め、交流磁気特性を改善できること、Ａｌ拡散層を形成する位置を鋼部品の表層部とすることによって鋼材の磁気モーメントの低下を防止できるため交流磁気特性の改善効果が高くなることが判明した。このとき、Ａｌは均一に拡散浸透するため、軟磁性鋼部品の表層部には局所的にＡｌが濃化し過ぎた部分は生成しないため、非磁性相も形成されず、交流磁気特性の劣化も防止できることも明らかとなった。 Therefore, the present inventor has repeatedly studied about impregnating Al in the surface layer portion of the soft magnetic component by a method different from the powder coating method disclosed in Patent Document 3. As a result, when heat treatment is applied to a steel material having an Al coating on the surface and processed into a part shape, Al existing on the surface diffuses and penetrates uniformly into the steel material to form an Al diffusion layer. The diffusion layer can increase the electric resistance of the surface layer part and improve the AC magnetic characteristics, and by making the position where the Al diffusion layer is formed the surface layer part of the steel part, the magnetic moment of the steel material can be prevented from being lowered. It turned out that the improvement effect becomes high. At this time, since Al diffuses and penetrates uniformly, a portion where Al is excessively concentrated is not generated in the surface layer portion of the soft magnetic steel part, so a nonmagnetic phase is not formed, and AC magnetic characteristics are not deteriorated. It became clear that it could be prevented.
また、本発明では、表層部にＡｌ拡散層を設けることによって軟磁性鋼部品の交流磁気特性を改善できるため、軟磁性鋼部品の素材となる鋼材には、従来のように交流磁気特性を改善するために添加していた多量の合金元素を添加する必要がない。即ち、従来では、上記特許文献２に開示されているように、合金元素量を最適化することによって鋼材の電気抵抗を高め、交流磁気特性を改善していたが、本発明によれば、鋼材に含有させる合金元素量を低減しても上記Ａｌ拡散層によって交流磁気特性向上効果は発揮される。そのため本発明で用いる鋼材は、合金元素量を低減しているため、変形抵抗が小さく、変形能が良好になるため、部品形状に成形するときの冷間鍛造性も改善できる。 In the present invention, the AC magnetic characteristics of the soft magnetic steel parts can be improved by providing an Al diffusion layer in the surface layer portion. Therefore, the AC magnetic characteristics of the steel material used for the soft magnetic steel parts are improved as before. Therefore, it is not necessary to add a large amount of the alloying element that has been added. That is, conventionally, as disclosed in the above-mentioned Patent Document 2, the alloy element amount is optimized to increase the electrical resistance of the steel material and to improve the AC magnetic characteristics. Even if the amount of the alloy element contained in the alloy is reduced, the Al magnetic diffusion layer can exhibit the effect of improving the AC magnetic characteristics. Therefore, since the steel material used in the present invention has a reduced amount of alloy elements, the deformation resistance is small and the deformability is good, so that the cold forgeability when forming into a part shape can also be improved.
以上の知見に基づいて完成した本発明に係る軟磁性鋼部品は、
（１）軟磁性鋼部品の交流磁気特性を改善するために、表層部に、１〜１３質量％のＡｌを含有し、且つ最表面側から中心部に向かってＡｌ量が減少するＡｌ拡散層を形成し、且つ軟磁性鋼部品の最表面から５μｍ深さにおける最大Ａｌ濃度を１８質量％以下に抑えたうえで、Ａｌ拡散層の厚みを４０μｍ以上としている。
（２）上記Ａｌ拡散層を形成するには、表面にＡｌ皮膜を有し、部品形状に加工された鋼材を８５０℃以上で１時間以上加熱すればよい。
（３）一方、冷間鍛造性を改善するために、軟磁性鋼部品の素材となる鋼材に含有させる合金元素のうち、特に、Ｃ、Ｓｉ、Ｍｎ、ＣｒおよびＡｌの量の関係が所定値以下となるように化学成分組成を調整している。
The soft magnetic steel parts according to the present invention completed based on the above findings are
(1) Al diffusion layer containing 1 to 13% by mass of Al in the surface layer and reducing the amount of Al from the outermost surface side toward the center in order to improve the AC magnetic properties of the soft magnetic steel parts And the maximum Al concentration at a depth of 5 μm from the outermost surface of the soft magnetic steel part is suppressed to 18 mass% or less, and the thickness of the Al diffusion layer is set to 40 μm or more.
(2) In order to form the Al diffusion layer, a steel material having an Al film on the surface and processed into a part shape may be heated at 850 ° C. or more for 1 hour or more.
(3) On the other hand, in order to improve the cold forgeability, among the alloy elements contained in the steel material used as the material of the soft magnetic steel part, in particular, the relationship among the amounts of C, Si, Mn, Cr and Al is a predetermined value. The chemical component composition is adjusted to be as follows.
以下、本発明の軟磁性鋼部品について詳細に説明する。 Hereinafter, the soft magnetic steel part of the present invention will be described in detail.
本発明の軟磁性鋼部品は、表層部にＡｌ拡散層が形成されており、このＡｌ拡散層は、最表面側から中心部に向かってＡｌ量が減少している。Ａｌ濃度を傾斜させることで、効果的に交流磁気特性を向上させることができる。ここで、表層部とは、軟磁性鋼部品のうち最表面を含む表面近傍を意味し、例えば、最表面から深さ５００μｍ位置程度までの領域を指す。 In the soft magnetic steel part of the present invention, an Al diffusion layer is formed in the surface layer portion, and the Al content of the Al diffusion layer decreases from the outermost surface side toward the center portion. By alternating the Al concentration, AC magnetic characteristics can be effectively improved. Here, the surface layer portion means the vicinity of the surface including the outermost surface among the soft magnetic steel parts, and refers to, for example, a region from the outermost surface to a depth of about 500 μm.
上記Ａｌ拡散層は、Ａｌを１〜１３質量％の範囲で含有している。Ａｌが１質量％未満では、表層部の電気抵抗を高めることができないため、渦電流損を低減できず、交流磁気特性を改善できない。一方、Ａｌが１８質量％を超えると非磁性相が形成され、自発磁化の低下が生じる傾向が認められる。従って本発明では、最表面から中心部に向かってＡｌ量を測定したときに、Ａｌを１〜１３質量％含有している層をＡｌ拡散層とする。 The Al diffusion layer contains Al in the range of 1 to 13% by mass. If Al is less than 1% by mass, the electrical resistance of the surface layer portion cannot be increased, so that eddy current loss cannot be reduced and AC magnetic characteristics cannot be improved. On the other hand, when Al exceeds 18% by mass, a nonmagnetic phase is formed, and a tendency for spontaneous magnetization to decrease is observed. Therefore, in the present invention, when the amount of Al is measured from the outermost surface toward the center, a layer containing 1 to 13% by mass of Al is defined as an Al diffusion layer.
本発明では、上記Ａｌ拡散層の厚みを４０μｍ以上とする。Ａｌ拡散層の厚みが４０μｍ未満では、表層部の電気抵抗を充分に高めることができず、渦電流損が大きくなり、交流磁気特性を改善できない。従ってＡｌ拡散層の厚みは４０μｍ以上とし、好ましくは７０μｍ以上、より好ましくは１００μｍ以上である。なお、Ａｌ拡散層の厚みの上限は特に限定されず、２５０μｍを超えて生成していてもよいが、熱処理によるコスト増加を抑制する観点から、例えば、５００μｍ以下であればよい。 In the present invention, the thickness of the Al diffusion layer is set to 40 μm or more. If the thickness of the Al diffusion layer is less than 40 μm, the electrical resistance of the surface layer portion cannot be sufficiently increased, eddy current loss increases, and AC magnetic characteristics cannot be improved. Therefore, the thickness of the Al diffusion layer is 40 μm or more, preferably 70 μm or more, more preferably 100 μm or more. In addition, the upper limit of the thickness of the Al diffusion layer is not particularly limited, and may be generated exceeding 250 μm, but may be, for example, 500 μm or less from the viewpoint of suppressing cost increase due to heat treatment.
本発明では、表層部に上記Ａｌ拡散層を４０μｍ以上の厚みで形成する他、最表面から５μｍ深さにおける最大Ａｌ濃度を１８質量％以下に抑えることも重要である。Ａｌ拡散層を所定厚み以上形成したとしても、局所的にＡｌが濃化し過ぎて１８質量％を超えると、急激に自発磁化の低下が生じるため、交流磁気特性が劣化するからである。従って本発明では、最大Ａｌ濃度を１８質量％以下とする。最大Ａｌ濃度は１５質量％以下であることが好ましく、より好ましくは１０質量％以下である。 In the present invention, it is also important to suppress the maximum Al concentration at a depth of 5 μm from the outermost surface to 18% by mass or less in addition to forming the Al diffusion layer with a thickness of 40 μm or more on the surface layer portion. This is because even if the Al diffusion layer is formed to have a predetermined thickness or more, if Al is excessively concentrated locally and exceeds 18% by mass, the spontaneous magnetization rapidly decreases, and the AC magnetic characteristics deteriorate. Therefore, in the present invention, the maximum Al concentration is set to 18% by mass or less. The maximum Al concentration is preferably 15% by mass or less, and more preferably 10% by mass or less.
最表面から５μｍ深さにおけるＡｌ濃度を複数箇所で測定したときに、その最大値（Ａｌmax）と最小値（Ａｌmin）の比（Ａｌmax／Ａｌmin）が２以下であることが好ましい。Ａｌmax／Ａｌminの値を２以下に抑えることによって最表面から５μｍ深さにおけるＡｌ濃度のバラツキを低減できる。Ａｌmax／Ａｌminの値は、１．５以下であることが好ましい。 When the Al concentration at a depth of 5 μm from the outermost surface is measured at a plurality of locations, the ratio of the maximum value (Al max ) to the minimum value (Al min ) (Al max / Al min ) is preferably 2 or less. By suppressing the value of Al max / Al min to 2 or less, variation in Al concentration at a depth of 5 μm from the outermost surface can be reduced. The value of Al max / Al min is preferably 1.5 or less.
上記Ａｌ濃度は、最表面から５μｍ深さにおいて、複数箇所（例えば、４箇所以上）で測定すればよく、測定結果から最大値（Ａｌmax）と最小値（Ａｌmin）を求めればよい。これらのうち、最大値を最大Ａｌ濃度とする。 The Al concentration may be measured at a plurality of locations (for example, 4 locations or more) at a depth of 5 μm from the outermost surface, and the maximum value (Al max ) and the minimum value (Al min ) may be obtained from the measurement results. Of these, the maximum value is the maximum Al concentration.
上記Ａｌ濃度の測定位置を最表面から５μｍ深さとしたのは、Ａｌ濃度は、鋼材の最表面に対して垂直に切断した断面を樹脂に埋め込んだ試験片を用いて測定する必要があるため、試験片の最表面は、埋め込みに用いた樹脂の影響を受けて正確な測定ができないからである。 The measurement position of the Al concentration is 5 μm deep from the outermost surface because the Al concentration needs to be measured using a test piece in which a cross section cut perpendicularly to the outermost surface of the steel material is embedded in a resin. This is because the outermost surface of the test piece cannot be accurately measured due to the influence of the resin used for embedding.
上記Ａｌ濃度は、例えば、電子線マイクロプローブＸ線分析計（Ｅｌｅｃｔｒｏｎ Ｐｒｏｂｅ Ｘ−ｒａｙ Ｍｉｃｒｏ Ａｎａｌｙｚｅｒ；ＥＰＭＡ）で測定すればよい。 The Al concentration may be measured with, for example, an electron probe X-ray micro analyzer (EPMA).
次に、本発明に係る軟磁性鋼部品の素材となる鋼材の成分組成について説明する。 Next, the component composition of the steel material used as the material of the soft magnetic steel part according to the present invention will be described.
本発明で用いる鋼材は、Ｃ：０．００２〜０．２０％、Ｓｉ：１．２％以下（０％を含まない）、Ｍｎ：０．０５〜２．６％、Ｐ：０．０５％以下（０％を含まない）、Ｓ：０．０５％以下（０％を含まない）、Ｃｒ：４％以下（０％を含まない）、Ａｌ：０．００２〜２．２％、Ｎ：０．０１％以下（０％を含まない）、Ｏ：０．０３％以下（０％を含まない）、残部：鉄および不可避不純物で、且つ下記式（１）を満足している。式（１）中、［ ］は、各元素の含有量を示している。
１３×［Ｃ］＋２×［Ｓｉ］＋［Ｍｎ］＋［Ｃｒ］／５＋［Ａｌ］≦２．８ ・・・（１）
Steel materials used in the present invention are: C: 0.002 to 0.20%, Si: 1.2% or less (excluding 0%), Mn: 0.05 to 2.6%, P: 0.05% Or less (excluding 0%), S: 0.05% or less (not including 0%), Cr: 4% or less (not including 0%), Al: 0.002 to 2.2%, N: 0.01% or less (not including 0%), O: 0.03% or less (not including 0%), balance: iron and inevitable impurities, and satisfying the following formula (1). In the formula (1), [] indicates the content of each element.
13 × [C] + 2 × [Si] + [Mn] + [Cr] / 5 + [Al] ≦ 2.8 (1)
こうした範囲を規定した理由は次の通りである。 The reason for specifying such a range is as follows.
Ｃは、鋼材の強度と延性をバランスよく確保するために重要な元素である。しかしＣが０．２０％を超えると、強度が高くなり過ぎて変形抵抗が大きくなる。また、鋼中に固溶したＣにより部品成形時にひずみ時効が生じ、交流磁気特性も悪くなる。従ってＣは０．２０％以下、好ましくは０．１％以下、より好ましくは０．０８％以下である。Ｃは少ないほど強度が低下し、延性が向上するため冷間鍛造性が良好となる。しかしＣ量を低減し過ぎると鋼部品の強度が低下し過ぎる。また、電気抵抗が低くなり、交流磁気特性も劣化する。従ってＣは０．００２％以上、好ましくは０．００３％以上である。 C is an important element for ensuring the balance between strength and ductility of the steel material. However, if C exceeds 0.20%, the strength becomes too high and the deformation resistance increases. In addition, due to the C dissolved in the steel, strain aging occurs at the time of forming the part, and the AC magnetic characteristics also deteriorate. Therefore, C is 0.20% or less, preferably 0.1% or less, more preferably 0.08% or less. The smaller the C, the lower the strength and the better the ductility, so the cold forgeability becomes better. However, if the amount of C is reduced too much, the strength of the steel part will be reduced too much. Further, the electrical resistance is lowered and the AC magnetic characteristics are also deteriorated. Therefore, C is 0.002% or more, preferably 0.003% or more.
Ｓｉは、固溶することで鋼材の電気抵抗を大きくし、渦電流損を少なくして交流磁気特性を改善するのに寄与する元素である。また、鋼部品の金属組織をフェライト化し、交流磁気特性を向上する作用も有している。しかし１．２％を超えて含有させると、変形抵抗が大きくなる。従ってＳｉは１．２％以下、好ましくは１．０％以下、より好ましくは０．８％以下である。特に、鋼材の変形抵抗を小さくして冷間鍛造性を改善するには、Ｓｉを０．７％以下とすることが好ましく、より好ましくは０．５％以下、更に好ましくは０．１％以下である。 Si is an element that contributes to improving the AC magnetic characteristics by increasing the electrical resistance of the steel material by reducing the eddy current loss by solid solution. Moreover, it has the effect | action which ferritizes the metal structure of steel parts and improves an alternating current magnetic characteristic. However, if the content exceeds 1.2%, the deformation resistance increases. Therefore, Si is 1.2% or less, preferably 1.0% or less, more preferably 0.8% or less. In particular, in order to reduce the deformation resistance of the steel material and improve the cold forgeability, Si is preferably 0.7% or less, more preferably 0.5% or less, still more preferably 0.1% or less. It is.
Ｍｎは、溶製時に脱酸剤として用いられる元素であり、鋼中ではＳと結合してＳによる脆化を抑制する作用を有している。また、鋼中のＳと結合してＭｎＳを形成したり、鋼中の酸化物の周囲にＭｎＳが複合析出して複合析出物を形成することで、部品の電気抵抗を高める作用を有している。従ってＭｎは０．０５％以上、好ましくは０．１％以上、更に好ましくは０．１５％以上である。しかしＭｎが２．６％を超えると、変形抵抗が大きくなり過ぎて冷間鍛造性が劣化する。また、Ｍｎが過剰になると、磁気モーメントが低下し、交流磁気特性が劣化する。従ってＭｎは２．６％以下、好ましくは２％以下、より好ましくは１％以下、更に好ましくは０．５％以下である。 Mn is an element used as a deoxidizer during melting, and has an action of binding to S and suppressing embrittlement due to S in steel. In addition, it combines with S in steel to form MnS, or MnS forms a composite precipitate around oxides in steel to form a composite precipitate, thereby increasing the electrical resistance of the parts. Yes. Therefore, Mn is 0.05% or more, preferably 0.1% or more, more preferably 0.15% or more. However, if Mn exceeds 2.6%, the deformation resistance becomes too large and the cold forgeability deteriorates. Further, when Mn is excessive, the magnetic moment is lowered and the AC magnetic characteristics are deteriorated. Therefore, Mn is 2.6% or less, preferably 2% or less, more preferably 1% or less, and still more preferably 0.5% or less.
Ｐは、粒界に偏析して変形能を低下させ、冷間鍛造時に割れを発生させる原因となる。また、過剰に含有すると交流磁気特性も劣化させる。従ってＰは０．０５％以下、好ましくは０．０２％以下、更に好ましくは０．０１５％以下である。Ｐはできるだけ低減されていることが望ましい。 P segregates at the grain boundaries to lower the deformability and cause cracks during cold forging. Moreover, when it contains excessively, an alternating current magnetic characteristic will also be deteriorated. Therefore, P is 0.05% or less, preferably 0.02% or less, more preferably 0.015% or less. It is desirable that P is reduced as much as possible.
Ｓは、Ｍｎ等と結合して硫化物を形成し、この硫化物が粒界に析出することによって変形能が低下する。従ってＳは０．０５％以下、好ましくは０．０２％以下、より好ましくは０．０１５％以下である。 S combines with Mn or the like to form a sulfide, and this sulfide is precipitated at the grain boundary, so that the deformability is lowered. Therefore, S is 0.05% or less, preferably 0.02% or less, more preferably 0.015% or less.
Ｃｒは、鋼部品の電気抵抗を大きくし、渦電流損を低減して交流磁気特性を向上させるのに作用する元素である。また、鋼部品の金属組織をフェライト化し、交流磁気特性を向上する作用も有している。こうした作用を有効に発揮させるには、Ｃｒは０．００５％以上含有させることが好ましい。しかしＣｒが４％を超えると固溶したＣｒによりフェライト組織の硬度が上昇し過ぎるため変形能が低下し、冷間鍛造時に割れが発生する。従ってＣｒは４％以下、好ましくは２％以下、より好ましくは１％以下、更に好ましくは０．５％以下である。 Cr is an element that acts to increase the electrical resistance of steel parts, reduce eddy current loss, and improve AC magnetic properties. Moreover, it has the effect | action which ferritizes the metal structure of steel parts and improves an alternating current magnetic characteristic. In order to exhibit such an action effectively, it is preferable to contain Cr by 0.005% or more. However, if Cr exceeds 4%, the hardness of the ferrite structure is excessively increased by the solid solution of Cr, so that the deformability is lowered and cracking occurs during cold forging. Therefore, Cr is 4% or less, preferably 2% or less, more preferably 1% or less, and still more preferably 0.5% or less.
Ａｌは、鋼部品の電気抵抗を高め、渦電流損を低減して交流磁気特性を改善するのに作用する元素である。また、Ａｌは、ＳｉやＣｒと同様に、鋼部品の金属組織をフェライト化して交流磁気特性を向上する作用も有している。従ってＡｌは０．００２％以上、好ましくは０．００３％以上含有させる。しかし２．２％を超えて含有させると、鋼材の変形抵抗が大きくなり過ぎる。従ってＡｌは２．２％以下、好ましくは１％以下、より好ましくは０．８％以下、更に好ましくは０．５％以下、特に好ましくは０．１％以下である。 Al is an element that acts to increase the electrical resistance of steel parts, reduce eddy current loss, and improve AC magnetic properties. Al, like Si and Cr, also has the effect of improving the AC magnetic characteristics by ferritizing the metal structure of the steel part. Therefore, Al is contained in an amount of 0.002% or more, preferably 0.003% or more. However, if the content exceeds 2.2%, the deformation resistance of the steel material becomes too large. Therefore, Al is 2.2% or less, preferably 1% or less, more preferably 0.8% or less, still more preferably 0.5% or less, and particularly preferably 0.1% or less.
Ｎは、鋼材を時効硬化させる元素であり、０．０１％を超えて含有すると鋼材の変形能が低下し、冷間鍛造時に割れが発生する原因となる。従ってＮは０．０１％以下、好ましくは０．００８％以下、より好ましくは０．００５％以下である。Ｎはできるだけ低減することが望ましい。 N is an element that age hardens the steel, and if it exceeds 0.01%, the deformability of the steel decreases and causes cracking during cold forging. Therefore, N is 0.01% or less, preferably 0.008% or less, more preferably 0.005% or less. It is desirable to reduce N as much as possible.
Ｏ（酸素）は、鋼中に酸化物を形成し、鋼材の変形能を低下させて冷間鍛造時に割れを発生させる元素である。また、鋼中に形成された酸化物は交流磁気特性を劣化させる原因となる。従ってＯは０．０３％以下、好ましくは０．０１％以下、より好ましくは０．００５％以下である。Ｏはできるだけ低減することが望ましい。 O (oxygen) is an element that forms an oxide in the steel, reduces the deformability of the steel material, and generates cracks during cold forging. Moreover, the oxide formed in steel becomes a cause which degrades an alternating current magnetic characteristic. Therefore, O is 0.03% or less, preferably 0.01% or less, more preferably 0.005% or less. It is desirable to reduce O as much as possible.
本発明で用いる鋼材は、化学成分組成が上記範囲を満足すると共に、下記式（１）を満足する必要がある。下記式（１）は、鋼材に含まれる合金元素のうち、鋼材の変形抵抗に影響を及ぼす元素を抽出し、各元素の影響度合いに基づいて規定した関係式を示している。下記式（１）の左辺の値をＺ値としたとき、Ｚ値を２．８以下に抑えることによって変形抵抗を小さくでき、冷間鍛造性を改善できる。 The steel material used in the present invention needs to satisfy the following formula (1) as well as the chemical component composition satisfying the above range. The following formula (1) shows a relational expression defined based on the degree of influence of each element by extracting elements that affect the deformation resistance of the steel material from among the alloy elements contained in the steel material. When the value on the left side of the following formula (1) is the Z value, the deformation resistance can be reduced by suppressing the Z value to 2.8 or less, and the cold forgeability can be improved.
即ち、Ｃ、Ｓｉ、Ｍｎ、Ｃｒ、Ａｌは、鋼材の電気抵抗を高め、渦電流損を低減して交流磁気特性を改善するのに作用する元素である。従って従来では積極的に添加されていた。しかしこれらの元素は、いずれも鋼中に固溶したり、析出物を形成して鋼材の強度を高め、鋼材の変形抵抗を大きくするのにも作用する。そのため含有量が多くなると、冷間鍛造性が劣化する傾向が認められた。 That is, C, Si, Mn, Cr, and Al are elements that act to increase the electrical resistance of the steel material, reduce eddy current loss, and improve AC magnetic characteristics. Therefore, it has been actively added in the past. However, these elements all act as a solid solution in the steel or form precipitates to increase the strength of the steel material and increase the deformation resistance of the steel material. Therefore, the tendency for cold forgeability to deteriorate was recognized when content increased.
これに対し、本発明では、上述したように、軟磁性鋼部品の表層部にＡｌ拡散層を形成することで、交流磁気特性を改善できるため、Ｃ、Ｓｉ、Ｍｎ、Ｃｒ、Ａｌの含有量を低減することができる。従って本発明では、これらの元素の含有量に基づいて算出されるＺ値を２．８以下に抑えることで、鋼材の冷間鍛造性を向上させることができる。Ｚ値は、好ましくは２．５以下、より好ましくは２以下、更に好ましくは１以下である。
１３×［Ｃ］＋２×［Ｓｉ］＋［Ｍｎ］＋［Ｃｒ］／５＋［Ａｌ］≦２．８ ・・・（１）
On the other hand, in the present invention, as described above, by forming an Al diffusion layer in the surface layer portion of the soft magnetic steel part, AC magnetic characteristics can be improved, so the contents of C, Si, Mn, Cr, Al Can be reduced. Therefore, in this invention, the cold forgeability of steel materials can be improved by suppressing Z value computed based on content of these elements to 2.8 or less. The Z value is preferably 2.5 or less, more preferably 2 or less, and still more preferably 1 or less.
13 × [C] + 2 × [Si] + [Mn] + [Cr] / 5 + [Al] ≦ 2.8 (1)
上記鋼材の残部は、鉄および不可避不純物である。不可避不純物としては、原料、資材、製造設備等の状況によって混入する元素が許容される。 The balance of the steel material is iron and inevitable impurities. As inevitable impurities, elements mixed in depending on the situation of raw materials, materials, manufacturing equipment, etc. are allowed.
次に、上記軟磁性鋼部品を製造する方法について説明する。 Next, a method for producing the soft magnetic steel part will be described.
本発明の軟磁性鋼部品は、表面にＡｌ皮膜を有し、且つ部品形状に加工された鋼材を熱処理することで製造できる。Ａｌ皮膜を有する鋼材を熱処理することによって、鋼材の表層部にＡｌを均一に拡散浸透させることができるため、局所的にＡｌ濃度が高くなることを防止しつつ交流磁気特性の向上に寄与する上記Ａｌ拡散層を形成できる。また、本発明で用いる鋼材は、上述したように、Ｃ、Ｓｉ、Ｍｎ、Ｃｒ、Ａｌの合金元素量に基づいて算出される上記Ｚ値を所定値以下に抑えているため、変形抵抗が小さくなり、冷間鍛造性を良好にできるという作用も発揮される。 The soft magnetic steel part of the present invention can be manufactured by heat-treating a steel material having an Al film on the surface and processed into a part shape. By heat treating a steel material having an Al film, Al can be uniformly diffused and permeated into the surface layer portion of the steel material, thus contributing to improvement of AC magnetic characteristics while preventing local increase in Al concentration. An Al diffusion layer can be formed. In addition, as described above, the steel material used in the present invention has a low deformation resistance because the Z value calculated based on the alloy element amounts of C, Si, Mn, Cr, and Al is suppressed to a predetermined value or less. Thus, the effect of improving the cold forgeability is also exhibited.
熱処理前の上記鋼材は、表面にＡｌ皮膜を有し、部品形状に加工されていればよく、鋼材の表面にＡｌ皮膜を形成する工程と、鋼材を部品形状に加工する工程の順番は特に限定されない。即ち、上記鋼材を部品形状に加工してからＡｌ皮膜を形成してもよいし、上記鋼材にＡｌ皮膜を形成してから部品形状に加工してもよい。部品形状への加工は、冷間鍛造によって行えばよい。 The steel material before the heat treatment only needs to have an Al film on the surface and processed into a part shape, and the order of the process of forming the Al film on the surface of the steel material and the process of processing the steel material into a part shape is particularly limited. Not. That is, the Al film may be formed after the steel material is processed into a part shape, or the Al film may be formed after forming the Al film on the steel material. Processing into a part shape may be performed by cold forging.
鋼材の表面にＡｌ皮膜を形成する方法は特に限定されず、例えば、Ａｌ薄膜接合拡散法、化学気相蒸着（ＣＶＤ）法、物理気相蒸着（ＰＶＤ）法、めっき法等が挙げられる。めっき法としては、溶融Ａｌめっき法や電気めっき法が挙げられる。これらの中でも溶融Ａｌめっき法によって製造することが好ましい。 The method for forming the Al film on the surface of the steel material is not particularly limited, and examples thereof include an Al thin film bonding diffusion method, a chemical vapor deposition (CVD) method, a physical vapor deposition (PVD) method, and a plating method. Examples of the plating method include a molten Al plating method and an electroplating method. Among these, it is preferable to manufacture by the hot Al plating method.
溶融Ａｌめっき法でＡｌ皮膜を形成する場合は、例えば、めっき浴として、純Ａｌめっき浴や、Ｓｉを１５質量％以下（０質量％を含まない）含有するＡｌめっき浴を用い、めっき浴の温度を８００℃以下（例えば、６５０〜７００℃）、浸漬時間を１〜１０分間とすればよい。 When forming an Al film by the hot-dip Al plating method, for example, a pure Al plating bath or an Al plating bath containing 15% by mass or less (not including 0% by mass) of Si is used as a plating bath. What is necessary is just to make temperature into 800 degrees C or less (for example, 650-700 degreeC), and immersion time for 1 to 10 minutes.
上記熱処理は、８５０℃以上で１時間以上加熱する必要がある。加熱温度が８５０℃を下回るか、加熱時間が１時間より短いと、Ａｌが鋼材内部へ充分に拡散浸透しないため、所望のＡｌ拡散層を形成することができない。また、拡散浸透しないＡｌが最表面から５μｍ深さに残留するため、最大Ａｌ濃度が１８質量％を超え、交流磁気特性が劣化する。 The heat treatment needs to be heated at 850 ° C. or higher for 1 hour or longer. When the heating temperature is lower than 850 ° C. or the heating time is shorter than 1 hour, Al does not sufficiently diffuse and penetrate into the steel material, so that a desired Al diffusion layer cannot be formed. Moreover, since Al which does not diffuse and permeate remains at a depth of 5 μm from the outermost surface, the maximum Al concentration exceeds 18% by mass, and the AC magnetic characteristics deteriorate.
上記加熱温度は９００℃以上とすることが好ましく、より好ましくは９５０℃以上である。加熱温度は、Ａｌを表面側から内部に向かって拡散浸透させるために、できるだけ高く設定することが望ましい。高温加熱することで、表層部にＦｅＡｌなどの非磁性相が生成するのを抑制できる。 The heating temperature is preferably 900 ° C. or higher, more preferably 950 ° C. or higher. The heating temperature is desirably set as high as possible in order to diffuse and infiltrate Al from the surface side toward the inside. By heating at a high temperature, generation of a nonmagnetic phase such as FeAl in the surface layer portion can be suppressed.
上記加熱時間は３時間以上であることが好ましく、より好ましくは５時間以上である。加熱時間は、Ａｌを表面側から内部に向かって拡散浸透させるために、できるだけ長くすることが望ましい。但し、加熱時間を長くし過ぎると生産性が悪くなるため、上限は例えば１５時間とするのがよい。 The heating time is preferably 3 hours or longer, more preferably 5 hours or longer. The heating time is desirably as long as possible in order to diffuse and infiltrate Al from the surface side toward the inside. However, if the heating time is too long, the productivity will deteriorate, so the upper limit is preferably set to 15 hours, for example.
上記熱処理は、還元性雰囲気で行うのがよい。還元性ガスとしては、例えば、水素を含有すればよい。 The heat treatment is preferably performed in a reducing atmosphere. As the reducing gas, for example, hydrogen may be contained.
上記加熱温度に加熱するときの昇温速度は、例えば、１００〜４００℃／時間とすればよい。また、熱処理後、室温まで冷却するときの降温速度は、例えば、１００〜４００℃／時間とすればよい。 What is necessary is just to let the temperature increase rate when heating to the said heating temperature be 100-400 degreeC / hour, for example. Moreover, what is necessary is just to let the temperature fall rate when cooling to room temperature after heat processing be 100-400 degreeC / hour, for example.
こうして得られる本発明に係る軟磁性鋼部品は、例えば、自動車や産業機械に実装されている部品のうち、磁力を介して駆動する電装部品や電磁コイルの鉄芯として用いられる。 The thus obtained soft magnetic steel part according to the present invention is used, for example, as an electrical component driven by magnetic force or an iron core of an electromagnetic coil among parts mounted on automobiles and industrial machines.
以下、実施例を挙げて本発明をより具体的に説明するが、本発明はもとより下記実施例によって制限を受けるものではなく、前・後記の趣旨に適合し得る範囲で適当に変更を加えて実施することも勿論可能であり、それらはいずれも本発明の技術的範囲に包含される。 EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.
下記実験例１では、軟磁性鋼部品の素材となる鋼材の冷間鍛造性について評価し、下記実験例２では、実験例１で得られた冷間鍛造性に優れた鋼材を用いて製造した軟磁性鋼部品の交流磁気特性を評価した。 In Experimental Example 1 below, the cold forgeability of a steel material used as a material for a soft magnetic steel part was evaluated. In Experimental Example 2 below, the steel material having excellent cold forgeability obtained in Experimental Example 1 was used. The AC magnetic properties of soft magnetic steel parts were evaluated.
［実験例１］
下記表１に示す化学成分組成の鋼（残部は鉄および不可避不純物）を真空溶製して１５０ｋｇの溶製材を作製した。下記表１に、上記式（１）の左辺の値（Ｚ値）を算出して示す。［ ］は、各元素の含有量を示している。
Ｚ値＝１３×［Ｃ］＋２×［Ｓｉ］＋［Ｍｎ］＋［Ａｌ］＋［Ｃｒ］／５
得られた溶製材を鍛伸加工して直径４０ｍｍの鋼材を製造し、次の手順で冷間鍛造性を評価した。
[Experimental Example 1]
A steel having a chemical composition shown in Table 1 below (the balance is iron and inevitable impurities) was vacuum-melted to prepare 150 kg of a melted material. In Table 1 below, the value (Z value) on the left side of the above formula (1) is calculated and shown. [] Indicates the content of each element.
Z value = 13 × [C] + 2 × [Si] + [Mn] + [Al] + [Cr] / 5
The obtained molten material was forged to produce a steel material having a diameter of 40 mm, and the cold forgeability was evaluated by the following procedure.
〈冷間鍛造性の評価〉
鋼材の冷間鍛造性は、試験片を５０％圧縮加工したときの変形抵抗と、圧縮加工したときの変形能で評価した。具体的には、鋼材の変形抵抗（Ｎ／ｍｍ2）は、上記鋼材から直径１６ｍｍ×高さ２４ｍｍの試験片を切り出し、試験片の高さが５０％となるように圧縮加工して測定した。圧縮加工は、ひずみ速度１０／秒で端面拘束圧縮して行った。測定した変形抵抗を下記表２に示す。本発明では、変形抵抗が５８０Ｎ／ｍｍ2未満を合格、５８０Ｎ／ｍｍ2以上を不合格として評価した。
<Evaluation of cold forgeability>
The cold forgeability of the steel material was evaluated by the deformation resistance when the test piece was 50% compressed and the deformability when the sample was compressed. Specifically, the deformation resistance (N / mm 2 ) of the steel material was measured by cutting a test piece having a diameter of 16 mm × a height of 24 mm from the steel material and compressing the test piece so that the height of the test piece was 50%. . The compression process was performed by constraining the end face at a strain rate of 10 / sec. The measured deformation resistance is shown in Table 2 below. In this invention, deformation resistance evaluated less than 580 N / mm < 2 > as pass, and evaluated 580 N / mm < 2 > or more as failure.
また、測定した変形抵抗の値と上記Ｚ値との関係を図１に示す。 The relationship between the measured deformation resistance value and the Z value is shown in FIG.
一方、鋼材の変形能は、上記条件で圧縮加工した後、試験片を目視および光学顕微鏡（観察倍率：４０倍）で観察し、割れ発生の有無を調べて評価した。割れ発生の有無を下記表２に示す。割れが発生してない場合を合格、割れが発生している場合を不合格とする。 On the other hand, the deformability of the steel material was evaluated by performing compression processing under the above conditions and then observing the test piece with the naked eye and an optical microscope (observation magnification: 40 times) to check for the presence of cracks. The presence or absence of cracking is shown in Table 2 below. The case where the crack does not occur is passed, and the case where the crack is generated is rejected.
本発明では、上記変形抵抗と変形能の両方が合格基準を満足している場合を「冷間鍛造性に優れている」と評価し、少なくともいずれか一方が合格基準を満足していない場合を「冷間鍛造性に劣る」と評価した。 In the present invention, the case where both the deformation resistance and the deformability satisfy the acceptance criteria is evaluated as "excellent in cold forgeability", and at least one of the cases does not satisfy the acceptance criteria. It was evaluated as “inferior in cold forgeability”.
下記表２と図１から次のように考察できる。 The following table 2 and FIG. 1 can be considered as follows.
Ｎｏ．１、２、４、６、１０、１２は、鋼材の成分組成が本発明で規定する要件を満足する例であり、変形抵抗が５８０Ｎ／ｍｍ2未満で、且つ圧縮加工時に割れが発生しておらず、冷間鍛造性に優れている。 No. 1, 2, 4, 6, 10, 12 are examples in which the component composition of the steel material satisfies the requirements specified in the present invention, the deformation resistance is less than 580 N / mm 2 , and cracking occurs during compression processing. It is excellent in cold forgeability.
これに対し、Ｎｏ．３、５、７〜９、１１、１３〜１６は、鋼材の成分組成が本発明で規定する要件を満足していない例であり、変形抵抗が５８０Ｎ／ｍｍ2以上であるか、圧縮加工時に割れが発生したため、冷間鍛造性に劣っている。 In contrast, no. 3, 5, 7-9, 11, 13-16 are examples in which the component composition of the steel material does not satisfy the requirements defined in the present invention, and the deformation resistance is 580 N / mm 2 or more, or during compression processing Due to the occurrence of cracks, the cold forgeability is poor.
詳細には、Ｎｏ．３、５、７、１３は、夫々、Ｃ、Ｓｉ、Ｍｎ、Ａｌが本発明で規定する上限値を超えている例であり、上記Ｚ値が２．８より大きいため、変形抵抗が５８０Ｎ／ｍｍ2以上になった。Ｎｏ．８は、Ｐが本発明で規定する上限値を超えている例である。Ｐの粒界偏析量が増加したため、変形能が低下し、圧縮加工時に割れが発生した。Ｎｏ．９は、Ｓが本発明で規定する上限値を超えている例である。硫化物が粒界に多く析出したため、変形能が低下し、割れが発生した。Ｎｏ．１１は、Ｃｒが本発明で規定する上限値を超えている例である。固溶したＣｒによりフェライト組織の硬度が上昇し過ぎて変形能が低下し、圧縮加工時に割れが発生した。Ｎｏ．１４は、Ｎが本発明で規定する上限値を超えている例である。過剰なＮによって時効硬化して変形能が低下し、割れが発生した。Ｎｏ．１５は、Ｏが本発明で規定する上限値を超えている例である。過剰なＯにより鋼中に酸化物が多く生成し、この酸化物が鋼材の変形能を低下させ、圧縮加工時に割れが発生した。Ｎｏ．１６は、成分組成は本発明で規定する範囲を満足しているが、Ｃ、Ｓｉ、Ｍｎ、ＡｌおよびＣｒの量が多いため、上記Ｚ値が２．８を超えた例である。従って変形抵抗が５８０Ｎ／ｍｍ2以上となり、冷間鍛造性に劣っている。 Specifically, no. 3, 5, 7, and 13 are examples in which C, Si, Mn, and Al exceed the upper limit values defined in the present invention. Since the Z value is larger than 2.8, the deformation resistance is 580 N / mm 2 or more. No. 8 is an example in which P exceeds the upper limit defined in the present invention. Since the grain boundary segregation amount of P increased, the deformability decreased and cracking occurred during compression processing. No. 9 is an example in which S exceeds the upper limit defined in the present invention. Since a large amount of sulfides precipitated at the grain boundaries, the deformability decreased and cracking occurred. No. 11 is an example in which Cr exceeds the upper limit defined in the present invention. Due to the solid solution of Cr, the hardness of the ferrite structure increased too much and the deformability decreased, and cracking occurred during compression processing. No. 14 is an example in which N exceeds the upper limit defined in the present invention. Excess N caused age hardening, resulting in reduced deformability and cracking. No. 15 is an example in which O exceeds the upper limit defined in the present invention. Excess O produced a large amount of oxide in the steel, and this oxide reduced the deformability of the steel material, and cracking occurred during compression processing. No. No. 16 is an example in which the Z value exceeds 2.8 because the component composition satisfies the range specified in the present invention, but the amount of C, Si, Mn, Al and Cr is large. Accordingly, the deformation resistance is 580 N / mm 2 or more, and the cold forgeability is poor.
［実験例２］
上記実験例１で得られた本発明で規定する成分組成を満足する鋼種Ａおよび鋼種Ｄからリング状の試験片を切り出し、この試験片にＡｌ拡散層を設けたときの交流磁気特性を次の手順で評価した。
[Experiment 2]
A ring-shaped test piece was cut out from steel type A and steel type D satisfying the component composition defined in the present invention obtained in Experimental Example 1, and the AC magnetic characteristics when an Al diffusion layer was provided on the test piece were as follows. The procedure was evaluated.
上記実験例１で得られた鋼材（直径４０ｍｍ）から、外径３８ｍｍ、内径３０ｍｍ、厚み４ｍｍのリング状試験片を切り出し、この試験片の表面に、溶融Ａｌめっき法によりＡｌ皮膜を形成した後、熱処理して表面のＡｌを試験片内部へ拡散浸透させた。また、比較例では、粉末塗布法により試験片の表面から内部へＡｌを拡散浸透させた。 After cutting out a ring-shaped test piece having an outer diameter of 38 mm, an inner diameter of 30 mm, and a thickness of 4 mm from the steel material (diameter 40 mm) obtained in Experimental Example 1, and forming an Al film on the surface of the test piece by a molten Al plating method The surface Al was diffused and penetrated into the test piece by heat treatment. In the comparative example, Al was diffused and penetrated from the surface of the test piece to the inside by a powder coating method.
溶融Ａｌめっきは、上記リング状試験片を、Ｓｉを約１０質量％含有する溶融Ａｌめっき浴（浴温は６７０℃）に２分浸漬して行った。浸漬後、水素還元雰囲気中で、下記表３に示す温度まで昇温速度３００℃／時間で加熱した後、この温度で下記表３に示す時間保持して熱処理し、Ａｌを試験片内部へ拡散浸透させた。熱処理後は、室温まで降温速度３００℃／時間で室温まで冷却した。 The molten Al plating was performed by immersing the ring-shaped test piece in a molten Al plating bath (bath temperature: 670 ° C.) containing about 10% by mass of Si for 2 minutes. After immersion, the sample was heated in a hydrogen reduction atmosphere to the temperature shown in Table 3 below at a rate of temperature increase of 300 ° C./hour, then kept at this temperature for the time shown in Table 3 below, and heat treated to diffuse Al into the specimen. Infiltrated. After the heat treatment, it was cooled to room temperature at a temperature lowering rate of 300 ° C./hour.
粉末塗布法では、Ａｌ粉末（５００ｇ）およびＡｌ2Ｏ3粉末（５００ｇ）を等量混合した混合粉に、ＮＨ4Ｃｌを１０ｇ加えたものをスレンレスケースに入れ、この中に上記リング状試験片を埋め込み、水素還元雰囲気中で、９００℃で、３時間保持して熱処理し、Ａｌを試験片内部へ拡散浸透させた。 In the powder coating method, a mixed powder obtained by mixing equal amounts of Al powder (500 g) and Al 2 O 3 powder (500 g) and 10 g of NH 4 Cl is placed in a slushless case, and the above ring-shaped test piece is contained therein. Was embedded and heat-treated in a hydrogen reduction atmosphere at 900 ° C. for 3 hours to diffuse and infiltrate Al into the test piece.
下記表３に、Ａｌ皮膜を形成した方法、熱処理時の加熱温度、および保持時間を夫々示す。 Table 3 below shows the method of forming the Al film, the heating temperature during the heat treatment, and the holding time, respectively.
次に、Ａｌ拡散層を形成した試験片の最表面から５μｍ深さにおけるＡｌ濃度をＥＰＭＡ（日本電子株式会社製「ＪＸＡ−８９００ＲＬ（装置名）」）で測定した。測定は４箇所で行った。 Next, the Al concentration at a depth of 5 μm from the outermost surface of the test piece on which the Al diffusion layer was formed was measured with EPMA (“JXA-8900RL (device name)” manufactured by JEOL Ltd.). The measurement was performed at four places.
Ａｌ皮膜を溶融Ａｌめっき法で形成したものを熱処理して得られた試験片では、測定箇所を変えてもＡｌ濃度の測定結果にバラツキは殆ど無かったため、下記表３には４箇所で測定した結果の平均値を最大Ａｌ濃度として示した。なお、４箇所で測定したときのＡｌ濃度の最大値（Ａｌmax）と最小値（Ａｌmin）の比（Ａｌmax／Ａｌmin）は、２以下であった。 In the test piece obtained by heat-treating an Al film formed by the hot-dip Al plating method, there was almost no variation in the Al concentration measurement result even when the measurement location was changed. The average value of the results was shown as the maximum Al concentration. The ratio (Al max / Al min ) between the maximum value (Al max ) and the minimum value (Al min ) of the Al concentration when measured at four locations was 2 or less.
一方、粉末塗布法によりＡｌを拡散浸透させた試験片では、測定箇所によってＡｌ濃度の測定結果にバラツキがあったため、下記表３には４箇所で測定した結果を最大Ａｌ濃度の欄に個別に示した。表３から明らかなように、粉末塗布法では、最表面から５μｍ深さにおけるＡｌ濃度の最大値（Ａｌmax）と最小値（Ａｌmin）の比（Ａｌmax／Ａｌmin）は、２を超えていることが分かる。 On the other hand, in the test piece in which Al was diffused and infiltrated by the powder coating method, the measurement result of the Al concentration varied depending on the measurement location. Therefore, in Table 3 below, the measurement results at four locations are individually entered in the column for the maximum Al concentration. Indicated. As is apparent from Table 3, in the powder coating method, the ratio (Al max / Al min ) between the maximum value (Al max ) and the minimum value (Al min ) of Al concentration at a depth of 5 μm from the outermost surface exceeds 2 I understand that
また、Ａｌ拡散層を形成した試験片の表層部におけるＡｌ濃度を上記ＥＰＭＡで測定し、１〜１３質量％のＡｌを含有するＡｌ拡散層の厚みを求めた。結果を下記表３に示す。また、試験片の表層部では、最表面のＡｌ量が最も多く、中心部に向かうほどＡｌ量は減少しており、傾斜組成であることが分かった。 Further, the Al concentration in the surface layer portion of the test piece on which the Al diffusion layer was formed was measured by the above EPMA, and the thickness of the Al diffusion layer containing 1 to 13% by mass of Al was determined. The results are shown in Table 3 below. Moreover, in the surface layer part of the test piece, the amount of Al on the outermost surface was the largest, and the amount of Al decreased toward the center, indicating that the composition had a gradient composition.
次に、熱処理して得られた試験片の交流磁気特性を評価した。 Next, the AC magnetic characteristics of the test pieces obtained by heat treatment were evaluated.
〈交流磁気特性の評価〉
交流磁気特性は、試験片の交流最大磁束密度を測定して評価した。交流最大磁束密度の値が大きくなるということは、Ａｌ拡散層が形成されることで表層部の電気抵抗が大きくなり、渦電流損が低減される結果、交流磁気特性が改善されていることを示している。詳細な測定方法は次の通りである。熱処理した試験片に、磁界印加用の１次コイルと磁束検出用の２次コイルを巻線し、自動磁化測定装置（岩通製ＢＨアナライザ：ＳＹ−８２３２）を用いてＢ−Ｈ曲線を測定し、交流最大磁束密度を求めた。Ｂ−Ｈ曲線を測定するにあたって、鉄損に伴う発熱によって、試験片の温度が上昇するのを防止するため、試験片は絶縁処理したうえで、２０℃の水中に浸漬しながら測定を行った。交流最大磁束密度は、磁界振幅を４０００Ａ／ｍ、周波数を１０ｋＨｚとしたときの値を求めた。結果を下記表３に示す。
<Evaluation of AC magnetic characteristics>
The AC magnetic characteristics were evaluated by measuring the AC maximum magnetic flux density of the test piece. An increase in the value of the AC maximum magnetic flux density means that the formation of the Al diffusion layer increases the electrical resistance of the surface layer portion and reduces eddy current loss, resulting in improved AC magnetic characteristics. Show. The detailed measurement method is as follows. A primary coil for applying a magnetic field and a secondary coil for detecting magnetic flux are wound around a heat-treated test piece, and a BH curve is measured using an automatic magnetization measuring device (Iwatsu BH analyzer: SY-8232). The maximum AC magnetic flux density was obtained. In measuring the BH curve, in order to prevent the temperature of the test piece from rising due to heat generated by iron loss, the test piece was subjected to insulation treatment and then measured while immersed in water at 20 ° C. . The AC maximum magnetic flux density was determined when the magnetic field amplitude was 4000 A / m and the frequency was 10 kHz. The results are shown in Table 3 below.
比較材として、上記鋼種Ａおよび鋼種Ｄから切り出したリング状の試験片に、Ａｌ拡散層を設けないで、上記と同様に、磁界印加用の１次コイルと磁束検出用の２次コイルを巻線し、Ｂ−Ｈ曲線を測定して交流最大磁束密度を求めた。その結果、鋼種Ａの交流最大磁束密度は１２２ｍＴ、鋼種Ｄの交流最大磁束密度は１９０ｍＴであった。Ａｌ拡散層を設けなった場合の交流最大磁束密度に対するＡｌ拡散層を設けた場合の交流最大磁束密度の比（Ａｌ拡散層有り／Ａｌ拡散層無し）を算出し、下記表３に示す。 As a comparison material, a primary coil for magnetic field application and a secondary coil for magnetic flux detection were wound on a ring-shaped test piece cut out from the above steel types A and D without providing an Al diffusion layer in the same manner as described above. The AC maximum magnetic flux density was determined by measuring the BH curve. As a result, the AC maximum magnetic flux density of steel type A was 122 mT, and the AC maximum magnetic flux density of steel type D was 190 mT. The ratio of the AC maximum magnetic flux density when the Al diffusion layer is provided to the AC maximum magnetic flux density when the Al diffusion layer is provided (with Al diffusion layer / without Al diffusion layer) is calculated and shown in Table 3 below.
交流最大磁束密度の比の値に基づいて、下記基準で交流磁気特性を評価し、評価結果を下記表３に併せて示す。 Based on the ratio value of the AC maximum magnetic flux density, AC magnetic characteristics are evaluated according to the following criteria, and the evaluation results are also shown in Table 3 below.
＜評価基準＞
◎（合格）：交流最大磁束密度の比が１．３０以上
（即ち、Ａｌ拡散層を設けなかった比較材の交流最大磁束密度に対して３０％以上増加。）
○（合格）：交流最大磁束密度の比が１．１０以上、１．３０未満
（即ち、Ａｌ拡散層を設けなかった比較材の交流最大磁束密度に対して１０％以上、３０％未満の範囲で増加。）
×（不合格）：交流最大磁束密度の比が１．１０未満
（即ち、Ａｌ拡散層を設けなかった比較材の交流最大磁束密度に対して増加量が１０％未満に留まる。）
<Evaluation criteria>
(Pass): Ratio of AC maximum magnetic flux density is 1.30 or more (that is, increase by 30% or more with respect to AC maximum magnetic flux density of the comparative material in which no Al diffusion layer is provided)
○ (Acceptance): AC maximum magnetic flux density ratio of 1.10 or more and less than 1.30 (that is, a range of 10% or more and less than 30% with respect to the AC maximum magnetic flux density of the comparative material in which no Al diffusion layer was provided. Increase in.)
X (failed): AC maximum magnetic flux density ratio is less than 1.10 (that is, the increase amount is less than 10% with respect to the AC maximum magnetic flux density of the comparative material in which the Al diffusion layer is not provided).
下記表３から次のように考察できる。 From Table 3 below, it can be considered as follows.
溶融Ａｌめっき法でＡｌ皮膜を形成した例のうち、Ｎｏ．２１、２２、３２、３３は、Ａｌ皮膜形成後の熱処理条件が本発明で規定する要件を満足していないため、試験片の最表面から５μｍ深さにＡｌが１８質量％を超えて存在し、また試験片の表層部にＡｌを１〜１３質量％含有するＡｌ拡散層を所定厚み以上形成できていないため、交流磁気特性を充分に改善できなかった。 Among the examples in which the Al film was formed by the hot-dip Al plating method, No. In Nos. 21, 22, 32, and 33, since the heat treatment conditions after the formation of the Al film do not satisfy the requirements defined in the present invention, Al exists at a depth of 5 μm from the outermost surface of the test piece and exceeds 18% by mass. Moreover, since an Al diffusion layer containing 1 to 13% by mass of Al was not formed in a predetermined thickness or more on the surface layer portion of the test piece, the AC magnetic characteristics could not be sufficiently improved.
これに対し、Ｎｏ．２３〜３１、３４〜４２は、Ａｌ皮膜形成後、本発明で規定する要件を満足する熱処理を行っているため、試験片の最表面から５μｍ深さにおける最大Ａｌ濃度を１８質量％以下に抑えたうえで、試験片の表層部にＡｌを１〜１３質量％含有するＡｌ拡散層を４０μｍ以上形成できているため、Ａｌ拡散層を設けない比較材に比べて交流磁気特性を改善できている。特に、Ａｌ拡散層の厚みが１００μｍ以上の場合には、交流最大磁束密度の比が１．３０以上となり、交流磁気特性に特に優れていることが分かる。 In contrast, no. Since Nos. 23 to 31 and 34 to 42 are subjected to heat treatment satisfying the requirements defined in the present invention after the formation of the Al film, the maximum Al concentration at a depth of 5 μm from the outermost surface of the test piece is suppressed to 18% by mass or less. In addition, since the Al diffusion layer containing 1 to 13% by mass of Al is formed in the surface layer portion of the test piece by 40 μm or more, the AC magnetic characteristics can be improved as compared with the comparative material in which the Al diffusion layer is not provided. . In particular, when the thickness of the Al diffusion layer is 100 μm or more, the ratio of the AC maximum magnetic flux density is 1.30 or more, indicating that the AC magnetic characteristics are particularly excellent.
一方、粉末塗布法でＡｌを拡散浸透させた例では、Ｎｏ．４３−１〜４３−４に示すように、試験片の最表面から５μｍ深さにおけるＡｌ濃度にバラツキが生じ、最大Ａｌ濃度が１８質量％を超える箇所があった。そのためＡｌを１〜１３質量％含むＡｌ拡散層を８０μｍの厚みで形成させても、試験片の表層部に非磁性相が形成され、交流磁気特性を充分に改善できなかった。 On the other hand, in the example in which Al was diffused and penetrated by the powder coating method, As shown in 43-1 to 43-4, variation occurred in the Al concentration at a depth of 5 μm from the outermost surface of the test piece, and there was a place where the maximum Al concentration exceeded 18 mass%. Therefore, even when an Al diffusion layer containing 1 to 13% by mass of Al was formed with a thickness of 80 μm, a nonmagnetic phase was formed on the surface layer portion of the test piece, and the AC magnetic characteristics could not be sufficiently improved.
次に、図２に、Ａｌ拡散層の厚みと交流最大磁束密度の比との関係を示す。図２では、鋼種Ａを用いたＮｏ．２１〜３１の結果を○で、鋼種Ｄを用いたＮｏ．３２〜４２の結果を▲で示した。図２から明らかなように、Ａｌ拡散層の厚みが大きくなるほど、交流最大磁束密度の比も大きくなる傾向が認められ、交流磁気特性を改善できることが分かる。 Next, FIG. 2 shows the relationship between the thickness of the Al diffusion layer and the ratio of the AC maximum magnetic flux density. In FIG. The results of Nos. 21 to 31 were ○, and No. using steel type D The results of 32-42 are indicated by ▲. As is apparent from FIG. 2, it can be seen that as the thickness of the Al diffusion layer increases, the ratio of the AC maximum magnetic flux density tends to increase, and the AC magnetic characteristics can be improved.
Claims (4)
Ｃ ：０．００２〜０．２０％（質量％の意味。以下同じ。）、
Ｓｉ：１．２％以下（０％を含まない）、
Ｍｎ：０．０５〜２．６％、
Ｐ ：０．０５％以下（０％を含まない）、
Ｓ ：０．０５％以下（０％を含まない）、
Ｃｒ：４％以下（０％を含まない）、
Ａｌ：０．００２〜２．２％、
Ｎ ：０．０１％以下（０％を含まない）、
Ｏ ：０．０３％以下（０％を含まない）、
残部：鉄および不可避不純物で、且つ
下記式（１）を満足するものであり、
表層部に、１〜１３質量％のＡｌを含有し、且つ最表面側から中心部に向かってＡｌ量が減少するＡｌ拡散層が形成された軟磁性鋼部品であり、
前記軟磁性鋼部品の最表面から５μｍ深さにおける最大Ａｌ濃度が１８質量％以下（０質量％を含まない）で、
前記Ａｌ拡散層の厚みが４０μｍ以上であることを特徴とする交流磁気特性に優れた軟磁性鋼部品。
１３×［Ｃ］＋２×［Ｓｉ］＋［Ｍｎ］＋［Ｃｒ］／５＋［Ａｌ］≦２．８ ・・・（１）
［式（１）中、［ ］は、各元素の含有量を示している。］ The chemical composition is
C: 0.002 to 0.20% (meaning mass%, the same shall apply hereinafter),
Si: 1.2% or less (excluding 0%),
Mn: 0.05 to 2.6%,
P: 0.05% or less (excluding 0%),
S: 0.05% or less (excluding 0%),
Cr: 4% or less (excluding 0%),
Al: 0.002 to 2.2%,
N: 0.01% or less (excluding 0%),
O: 0.03% or less (excluding 0%),
The balance: iron and inevitable impurities and satisfying the following formula (1),
A soft magnetic steel part in which an Al diffusion layer containing 1 to 13% by mass of Al in the surface layer part and having an Al amount decreasing from the outermost surface side toward the center part is formed,
The maximum Al concentration at a depth of 5 μm from the outermost surface of the soft magnetic steel part is 18% by mass or less (not including 0% by mass),
A soft magnetic steel part having excellent AC magnetic characteristics, wherein the thickness of the Al diffusion layer is 40 μm or more.
13 × [C] + 2 × [Si] + [Mn] + [Cr] / 5 + [Al] ≦ 2.8 (1)
[In Formula (1), [] has shown content of each element. ]
表面にＡｌ皮膜を有し、部品形状に加工された鋼材を８５０℃以上で１時間以上加熱することを特徴とする交流磁気特性に優れた軟磁性鋼部品の製造方法。 A method for producing the soft magnetic steel part according to claim 1,
A method for producing a soft magnetic steel part having excellent AC magnetic characteristics, characterized by heating a steel material having an Al coating on its surface and processed into a part shape at 850 ° C. or more for 1 hour or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009295985A JP5427596B2 (en) | 2009-12-25 | 2009-12-25 | Soft magnetic steel parts having excellent AC magnetic characteristics and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009295985A JP5427596B2 (en) | 2009-12-25 | 2009-12-25 | Soft magnetic steel parts having excellent AC magnetic characteristics and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2011137188A true JP2011137188A (en) | 2011-07-14 |
| JP5427596B2 JP5427596B2 (en) | 2014-02-26 |
Family
ID=44348881
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2009295985A Expired - Fee Related JP5427596B2 (en) | 2009-12-25 | 2009-12-25 | Soft magnetic steel parts having excellent AC magnetic characteristics and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5427596B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012153911A (en) * | 2011-01-21 | 2012-08-16 | Kobe Steel Ltd | Soft magnetic steel component for direct current |
| WO2014157302A1 (en) * | 2013-03-29 | 2014-10-02 | 株式会社神戸製鋼所 | Steel material having excellent corrosion resistance and excellent magnetic properties and production method therefor |
| WO2014174976A1 (en) * | 2013-04-22 | 2014-10-30 | オムロン株式会社 | Magnetic components, and electronic components provided with magnetic components |
| WO2014174975A1 (en) * | 2013-04-22 | 2014-10-30 | オムロン株式会社 | Magnetic component, electronic component using magnetic component, and production method for magnetic component |
| JP2016008314A (en) * | 2014-06-23 | 2016-01-18 | 新日鐵住金株式会社 | Fe-BASED METAL PLATE AND PRODUCTION METHOD THEREFOR |
| CN107275033A (en) * | 2017-05-23 | 2017-10-20 | 深圳顺络电子股份有限公司 | A kind of magnetically soft alloy material and preparation method thereof |
| CN112894093A (en) * | 2021-02-03 | 2021-06-04 | 中车青岛四方机车车辆股份有限公司 | Welding process for dissimilar steel |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4623816B1 (en) * | 1966-08-09 | 1971-07-08 | ||
| JPS52115746A (en) * | 1976-03-25 | 1977-09-28 | Nisshin Steel Co Ltd | Method of fabricating aluminum alloy for use in magnetic material |
| JPS5449936A (en) * | 1977-09-29 | 1979-04-19 | Pioneer Electronic Corp | High permiable* soft magnetic material and method of making same |
| JP2005298968A (en) * | 2004-03-17 | 2005-10-27 | Jfe Steel Kk | Steel sheet for magnetic shielding and its production method |
| JP2005298969A (en) * | 2004-03-17 | 2005-10-27 | Jfe Steel Kk | Steel sheet for magnetic shielding and its production method |
| JP2006328462A (en) * | 2005-05-25 | 2006-12-07 | Sumitomo Metal Ind Ltd | Soft magnetic steel |
-
2009
- 2009-12-25 JP JP2009295985A patent/JP5427596B2/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4623816B1 (en) * | 1966-08-09 | 1971-07-08 | ||
| JPS52115746A (en) * | 1976-03-25 | 1977-09-28 | Nisshin Steel Co Ltd | Method of fabricating aluminum alloy for use in magnetic material |
| JPS5449936A (en) * | 1977-09-29 | 1979-04-19 | Pioneer Electronic Corp | High permiable* soft magnetic material and method of making same |
| JP2005298968A (en) * | 2004-03-17 | 2005-10-27 | Jfe Steel Kk | Steel sheet for magnetic shielding and its production method |
| JP2005298969A (en) * | 2004-03-17 | 2005-10-27 | Jfe Steel Kk | Steel sheet for magnetic shielding and its production method |
| JP2006328462A (en) * | 2005-05-25 | 2006-12-07 | Sumitomo Metal Ind Ltd | Soft magnetic steel |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012153911A (en) * | 2011-01-21 | 2012-08-16 | Kobe Steel Ltd | Soft magnetic steel component for direct current |
| WO2014157302A1 (en) * | 2013-03-29 | 2014-10-02 | 株式会社神戸製鋼所 | Steel material having excellent corrosion resistance and excellent magnetic properties and production method therefor |
| US10593451B2 (en) | 2013-03-29 | 2020-03-17 | Kobe Steel, Ltd. | Steel material having excellent corrosion resistance and excellent magnetic properties and production method therefor |
| WO2014174976A1 (en) * | 2013-04-22 | 2014-10-30 | オムロン株式会社 | Magnetic components, and electronic components provided with magnetic components |
| WO2014174975A1 (en) * | 2013-04-22 | 2014-10-30 | オムロン株式会社 | Magnetic component, electronic component using magnetic component, and production method for magnetic component |
| JP2014216354A (en) * | 2013-04-22 | 2014-11-17 | オムロン株式会社 | Magnetic component, electronic component using the magnetic component, and method for producing the magnetic component |
| JP2014214319A (en) * | 2013-04-22 | 2014-11-17 | オムロン株式会社 | Magnetic component, and electronic component including magnetic component |
| JP2016008314A (en) * | 2014-06-23 | 2016-01-18 | 新日鐵住金株式会社 | Fe-BASED METAL PLATE AND PRODUCTION METHOD THEREFOR |
| CN107275033A (en) * | 2017-05-23 | 2017-10-20 | 深圳顺络电子股份有限公司 | A kind of magnetically soft alloy material and preparation method thereof |
| CN107275033B (en) * | 2017-05-23 | 2019-01-08 | 深圳顺络电子股份有限公司 | A kind of magnetically soft alloy material and preparation method thereof |
| CN112894093A (en) * | 2021-02-03 | 2021-06-04 | 中车青岛四方机车车辆股份有限公司 | Welding process for dissimilar steel |
| CN112894093B (en) * | 2021-02-03 | 2022-04-15 | 中车青岛四方机车车辆股份有限公司 | Welding process for dissimilar steel |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5427596B2 (en) | 2014-02-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5427596B2 (en) | Soft magnetic steel parts having excellent AC magnetic characteristics and manufacturing method thereof | |
| TWI406957B (en) | High-frequency iron loss low non-directional electromagnetic steel sheet and its manufacturing method | |
| JP4616935B2 (en) | Non-oriented electrical steel sheet and manufacturing method thereof | |
| JP5028992B2 (en) | Non-oriented electrical steel sheet and manufacturing method thereof | |
| JP5699601B2 (en) | Non-oriented electrical steel sheet and manufacturing method thereof | |
| JP6500980B2 (en) | Non-oriented electrical steel sheet | |
| WO2003002777A1 (en) | Nonoriented electromagnetic steel sheet | |
| JP6497145B2 (en) | Electrical steel sheet with high strength and excellent magnetic properties | |
| JP2007186790A (en) | High strength non-oriented electrical steel sheet and method for manufacture the same | |
| JPWO2020137500A1 (en) | Non-oriented electrical steel sheet | |
| TWI799219B (en) | Non-oriented electrical steel sheet, manufacturing method of non-oriented electrical steel sheet, electric motor, and manufacturing method of electric motor | |
| JP2007138259A (en) | Spring steel wire material superior in pickling characteristics | |
| JP5181439B2 (en) | Non-oriented electrical steel sheet | |
| KR102683224B1 (en) | Non-oriented electrical steel sheet | |
| JP2007031755A (en) | Method for producing non-oriented silicon steel sheet for rotor | |
| JP5615727B2 (en) | Soft magnetic steel parts for DC | |
| JP2006328461A (en) | Soft magnetic steel | |
| JP5416452B2 (en) | Soft magnetic steel materials, soft magnetic steel parts, and manufacturing methods thereof | |
| JP5547590B2 (en) | Soft magnetic steel parts having excellent AC magnetic characteristics and manufacturing method thereof | |
| JP5613134B2 (en) | Rotor core for permanent magnet motor | |
| JP2004339603A (en) | High-strength non-oriented electromagnetic steel sheet superior in high-frequency magnetic property, and manufacturing method therefor | |
| JP2006328462A (en) | Soft magnetic steel | |
| JP4502889B2 (en) | Soft magnetic steel material excellent in cold forgeability, cutting workability and AC magnetic characteristics, soft magnetic steel parts excellent in AC magnetic characteristics, and method for producing the same | |
| JP5651002B2 (en) | Soft magnetic steel parts having excellent AC magnetic characteristics and manufacturing method thereof | |
| JP5560923B2 (en) | Method for producing non-oriented electrical steel sheet with excellent magnetic properties in rolling direction |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20110901 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20130821 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20130903 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20131105 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20131126 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20131202 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 Ref document number: 5427596 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| LAPS | Cancellation because of no payment of annual fees |