JPH07197101A - Iron-phosphorus steel powder for powder metallurgy and production of sintered parts - Google Patents
Iron-phosphorus steel powder for powder metallurgy and production of sintered partsInfo
- Publication number
- JPH07197101A JPH07197101A JP5350316A JP35031693A JPH07197101A JP H07197101 A JPH07197101 A JP H07197101A JP 5350316 A JP5350316 A JP 5350316A JP 35031693 A JP35031693 A JP 35031693A JP H07197101 A JPH07197101 A JP H07197101A
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- powder
- iron
- phosphorus
- metallurgy
- alloy powder
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、寸法精度に優れた焼結
部品を与える粉末冶金用鉄−燐系鋼粉、及び該鋼粉を用
いた焼結部品の製造方法に関するものであり、本発明は
例えば焼結軟質磁性部品や焼結機械部品の製造に有効に
活用することができる。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron-phosphorus steel powder for powder metallurgy which gives a sintered part having excellent dimensional accuracy, and a method for producing a sintered part using the steel powder. INDUSTRIAL APPLICABILITY The invention can be effectively utilized for manufacturing, for example, a sintered soft magnetic component or a sintered mechanical component.
【０００２】[0002]
【従来の技術】粉末冶金法とは、物理的あるいは化学的
に微粉化された原料粉を金型に入れて圧縮成形した後に
焼結を行なって製品を得る方法であり、特に複雑な形状
の部品の成形に広く活用されている。こうした粉末冶金
法の特徴を充分に生かすには、焼結ままで高い寸法精度
が得られることが必要であるが、現実には必ずしも十分
な寸法精度が得られるとは限らず、焼結後に寸法調整の
為のサイジング、コインイング、あるいは機械加工等を
要することが少なくない。2. Description of the Related Art The powder metallurgy method is a method in which a physically or chemically pulverized raw material powder is put into a mold, compression-molded, and then sintered to obtain a product, which has a particularly complicated shape. Widely used for molding parts. In order to make full use of the characteristics of the powder metallurgy method, it is necessary to obtain high dimensional accuracy as it is sintered, but in reality it is not always possible to obtain sufficient dimensional accuracy. Often, sizing for adjustment, coining, or machining is required.
【０００３】ところで鉄−燐系鋼粉は、良好な軟質磁気
特性を発現する燒結部品材料として有用なものであり、
あるいはこれに炭素（Ｃ）や銅（Ｃｕ）等を添加するこ
とにより、機械構造部品用材料としても多用されてい
る。By the way, iron-phosphorus steel powder is useful as a sintered component material which exhibits good soft magnetic properties.
Alternatively, by adding carbon (C), copper (Cu), or the like to this, it is often used as a material for machine structural parts.
【０００４】このような鉄−燐系焼結部品を製造するた
めの鉄−燐（Ｆｅ−Ｐ）系原料粉としては、燐（Ｐ）を
溶解した溶湯をアトマイズ法によって粉末化したいわゆ
るプレアロイ粉と、純鉄粉に鉄−燐合金、燐酸あるいは
燐酸鉄等の燐供給源となる粉末を配合したプレミックス
粉がある。このうちプレアロイ粉は、非常に硬質である
ため、金型を用いた圧縮成形では高密度化が達成されに
くく、満足のいく磁気特性や機械強度が得られないとい
う性能上の問題に加えて、激しい金型損耗を招くという
問題を有している。一方、プレミックス粉では、圧縮性
は良好であるため高密度化は達成され易いという利点は
有しているものの、配合した燐が偏析を起こし易く、得
られる製品の寸法精度や磁気特性、或は機械的特性にば
らつきを生じ易いという問題がある。As an iron-phosphorus (Fe-P) -based raw material powder for producing such an iron-phosphorus-based sintered part, a so-called prealloy powder obtained by atomizing a molten metal in which phosphorus (P) is dissolved by an atomizing method is used. In addition, there is a premixed powder in which pure iron powder is mixed with a powder serving as a phosphorus supply source such as an iron-phosphorus alloy, phosphoric acid or iron phosphate. Of these, the pre-alloyed powder is extremely hard, so it is difficult to achieve high density by compression molding using a mold, and in addition to the performance problem that satisfactory magnetic properties and mechanical strength cannot be obtained, It has a problem of causing severe die wear. On the other hand, the premixed powder has an advantage that the densification can be easily achieved because the compressibility is good, but the compounded phosphorus is apt to segregate, and the dimensional accuracy and magnetic characteristics of the obtained product, Has a problem in that mechanical characteristics tend to vary.
【０００５】上記問題点を解決するものとして、例えば
特公昭５４−２１８０３号公報には、純鉄粉と１２〜１
７重量％の燐を含む鉄−燐合金粉末（平均粒径４５μｍ
以下）を、微量の鉱油と共に混合し、比較的低温で穏や
かに焼結した後に粉砕することによって、圧縮性に優
れ、かつ燐の偏析のない鉄粉を得る方法が開示されてい
る。As a solution to the above problems, for example, Japanese Patent Publication No. 54-21803 discloses pure iron powder and 12-1.
Iron-phosphorus alloy powder containing 7% by weight of phosphorus (average particle size 45 μm
The following method) is mixed with a trace amount of mineral oil, gently sintered at a relatively low temperature, and then pulverized to obtain an iron powder having excellent compressibility and no phosphorus segregation.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、上記の
特公昭５４−２１８０３号公報に開示された方法（部分
拡散型鉄粉の製造方法）は、従来のプレミッス粉に比べ
て燐の偏析防止には効果があるが、燐の供給源として燐
含有量の少ない（１２〜１７重量％）鉄−燐合金粉末を
使用しているので、希望する燐含量の鋼粉を得るには、
上記鉄−燐合金粉末を多量に添加しなければならず、こ
の鉄−燐合金粉末がかなり硬質であるため、やはり金型
の損耗が激しい。However, the method disclosed in Japanese Patent Publication No. 54-21803 (a method for producing a partially-diffused iron powder) is more effective in preventing phosphorus segregation than the conventional pre-miss powder. Since iron-phosphorus alloy powder having a small phosphorus content (12 to 17% by weight) is used as a source of phosphorus, which is effective, to obtain a steel powder having a desired phosphorus content,
Since the iron-phosphorus alloy powder must be added in a large amount, and the iron-phosphorus alloy powder is considerably hard, the die wear is severe.
【０００７】また上記技術では、原料鋼粉が硬質となる
ため圧縮成形時の密度が十分に上がり難い。しかも鉄−
燐合金粉末を純鉄粉との混合系で穏やかに焼結させてい
るので、鉄−燐合金粉末と純鉄粉の界面付近における燐
濃度は、燐＝１０．５重量％の共晶点（図４：鉄−燐２
元状態図参照）に近づいており、一般的な鋼粉系粉末冶
金の焼結温度である１１００〜１２５０℃では上記燐含
量の鉄−燐合金が溶融し、焼結の特に初期段階（焼結ネ
ックが充分に形成される前）で多量の液相が生じるた
め、プレミックス粉に比べて寸法収縮が著しく、寸法精
度の確保が困難になるという問題もある。更に、ロット
間の寸法変化のバラツキを小さくすることも困難であ
る。加えてこの部分拡散型鋼粉を製造する際には、水素
ガス雰囲気下での加熱（８００℃以下）を必要とするた
め、防爆構造の特殊な炉が必要となるという問題も指摘
される。Further, in the above technique, since the raw material steel powder becomes hard, it is difficult to sufficiently increase the density during compression molding. And iron-
Since the phosphorus alloy powder is gently sintered in a mixed system of pure iron powder, the phosphorus concentration in the vicinity of the interface between the iron-phosphorus alloy powder and the pure iron powder is phosphorus = 10.5 wt% at the eutectic point ( Figure 4: Iron-phosphorus 2
The iron-phosphorus alloy having the above phosphorus content is melted at a sintering temperature of 1100 to 1250 ° C., which is a sintering temperature of a general steel powder-based powder metallurgy, and particularly in the initial stage of sintering (sintering). Since a large amount of liquid phase is generated before the neck is sufficiently formed), there is a problem that dimensional shrinkage is remarkable as compared with the premix powder and it becomes difficult to secure dimensional accuracy. Further, it is difficult to reduce variation in dimensional change between lots. In addition, when manufacturing this partially diffused steel powder, heating (800 ° C. or lower) in a hydrogen gas atmosphere is required, and therefore a problem that a special furnace having an explosion-proof structure is required is pointed out.
【０００８】また鋼粉中の酸素量が焼結時の寸法精度に
影響を及ぼすことも一般的に知られているが、粉末冶金
用鋼粉は比表面積が大きいため、製造後の流通、保存時
に酸化され易いという問題があり、特にＰを多く含む鋼
粉末では、この傾向が著しい。そのため、従来はステア
リン酸亜鉛等の混合による発錆防止、あるいは特殊な除
湿を施した倉庫での保管、更に特殊な防湿袋への封入
（開平３−２９７７９号）等が利用されている。しかし
ながら、上記のうちステアリン酸亜鉛の混合による方法
だけでは、発錆防止効果が十分でなく、また除湿を施し
た倉庫や特殊な防湿袋を利用する方法は、経済的性に問
題がある。It is also generally known that the amount of oxygen in steel powder affects the dimensional accuracy during sintering, but since steel powder for powder metallurgy has a large specific surface area, it is distributed and stored after manufacture. There is a problem that it is easily oxidized, and this tendency is remarkable especially in the case of steel powder containing a large amount of P. Therefore, conventionally, rust prevention by mixing with zinc stearate or the like, storage in a special dehumidified warehouse, and enclosing in a special moisture-proof bag (Kaihei 3-29779) have been used. However, among the above methods, the method of mixing zinc stearate alone is not sufficient for the rust preventing effect, and the method of using a dehumidified warehouse or a special moisture-proof bag has a problem in economical efficiency.
【０００９】本発明は以上の様な問題を解決するために
なされたものであり、プレス成形時の圧縮成形性が良好
で高密度の圧粉成形体が得られ易く、しかも保管時等に
おける酸素の吸収も抑えられて、焼結時の寸法変化が少
なくて高い寸法精度の確保が容易であり、またＰの偏析
が少なくて、良好な磁気特性や機械的強度を有する焼結
部品を得ることのできる粉末冶金用鉄−燐系鉄粉、およ
び該粉末冶金用鉄−燐系鋼粉を用いた焼結部品の製造方
法を提供することを目的とする。The present invention has been made in order to solve the above problems, and has good compression moldability at the time of press molding, and it is easy to obtain a high-density powder compact, and moreover, oxygen during storage etc. It is also possible to obtain a sintered part that suppresses the absorption of iron, has a small dimensional change during sintering, can easily secure high dimensional accuracy, and has a small segregation of P, and has good magnetic characteristics and mechanical strength. An object of the present invention is to provide an iron-phosphorus-based iron powder for powder metallurgy and a method for producing a sintered component using the iron-phosphorus-based steel powder for powder metallurgy.
【００１０】[0010]
【課題を解決するための手段】本発明に係る粉末冶金用
鉄−燐系鋼粉は、燐含有量が１７〜２８重量％で平均粒
径が６３μｍ以下の鉄−燐合金粉末、あるいは該粉末と
炭素粉末及び／又は銅粉末を、バインダーによって粉末
冶金用鉄粉表面に付着させたものであることを要旨とす
る。The iron-phosphorus steel powder for powder metallurgy according to the present invention is an iron-phosphorus alloy powder having a phosphorus content of 17 to 28% by weight and an average particle size of 63 μm or less, or the powder. The gist is that carbon powder and / or copper powder are adhered to the surface of the iron powder for powder metallurgy with a binder.
【００１１】本発明に係る焼結部品の製造方法は、上記
鉄−燐合金粉末と、バインダー、あるいはこれらと炭素
粉末及び／又は銅粉末を、粉末冶金用鉄粉および潤滑材
と共に混合して成形し、焼結するところに要旨が存在す
る。In the method for producing a sintered part according to the present invention, the above-mentioned iron-phosphorus alloy powder and a binder, or these and carbon powder and / or copper powder are mixed together with iron powder for powder metallurgy and a lubricant to be molded. However, there is a gist at the place of sintering.
【００１２】[0012]
【作用及び実施例】本発明で用いるバインダーは、鉄−
燐（Ｆｅ−Ｐ）合金粉末あるいは炭素（Ｃ）粉末、銅
（Ｃｕ）粉末を、純鉄粉表面に均一に付着させる作用を
有している。従って、このようにして鉄−燐（Ｆｅ−
Ｐ）合金粉末等を純鉄粉表面に付着し造粒した本発明の
鋼粉は、流動性が良好で優れた圧縮成形性を有してお
り、たとえ薄肉・複雑形状部品の金型成形であっても設
計通りの形状を有する高密度の圧粉成形体を得ることが
できる。また硬質のＦｅ−Ｐ合金粉末粒子はバインダー
で包み込まれる様に造粒されているので、従来の鋼粉で
問題とされていた金型の損耗も抑制される。更に、鋼粉
に含有される酸素量は寸法変化率に影響を与えるが、上
述の様にバインダーがＦｅ−Ｐ合金粉末を包み込み、大
気と接触するのを防止することになるので、製造後の酸
素量の経時変化が小さく、酸素吸収による寸法変化率の
変動が小さくなる。FUNCTION AND EXAMPLE The binder used in the present invention is iron-
It has a function of uniformly adhering the phosphorus (Fe-P) alloy powder, the carbon (C) powder, or the copper (Cu) powder to the surface of the pure iron powder. Therefore, in this way, iron-phosphorus (Fe-
P) The steel powder of the present invention in which alloy powder or the like is adhered to the surface of pure iron powder and granulated has good fluidity and excellent compression moldability, and is suitable for mold molding of thin-walled / complex shaped parts. Even if there is, it is possible to obtain a high-density powder compact having a shape as designed. Further, since the hard Fe-P alloy powder particles are granulated so as to be wrapped with the binder, wear of the mold, which has been a problem with conventional steel powder, can be suppressed. Further, the amount of oxygen contained in the steel powder influences the dimensional change rate, but as described above, the binder wraps the Fe-P alloy powder and prevents contact with the atmosphere, so that The change in oxygen amount over time is small, and the change in the dimensional change rate due to oxygen absorption is small.
【００１３】しかも従来では、鋼粉の輸送、原料ホッパ
ーへの充填、成形用金型への充填等の工程の際に、Ｆｅ
−Ｐ合金粉末やＣ粉末、Ｃｕ粉末及び潤滑材の偏析が起
こっていたが、本発明の粉末冶金用鉄−燐系鋼粉は、母
材である鉄粉表面に上記Ｆｅ−Ｐ合金粉末等がバインダ
ーにより付着されているので、上記の様な鋼粉の輸送や
取扱い時におけるＰ等の偏析も防止される。Moreover, in the past, Fe was used during the steps of transporting steel powder, filling the raw material hopper, filling the molding die, etc.
-Segregation of P alloy powder, C powder, Cu powder and lubricant has occurred, but the iron-phosphorus steel powder for powder metallurgy of the present invention has the Fe-P alloy powder and the like on the surface of the iron powder as the base material. Since B is adhered by the binder, segregation of P and the like during transportation and handling of the steel powder as described above is also prevented.
【００１４】ことに本発明の粉末冶金用鉄−燐系鋼粉
は、圧縮成形が良好であるので圧縮成形により高密度の
圧縮成形体を得ることができ、保管時等における酸素吸
収量の低減とも相まってその後の焼結工程での寸法収縮
が最小限に抑えられるので、焼結製品としての寸法精度
を著しく高めることができ、焼結後の寸法調整の為の機
械加工等を最小限に抑えることができ、場合によっては
その様な寸法調整等が全く不要となる。しかも圧縮成形
時における金型の損耗が少なく、またＰ成分等の偏析も
起こらないので物性の均質な焼結製品を得ることができ
るといった様な利点がある。In particular, since the iron-phosphorus steel powder for powder metallurgy of the present invention is good in compression molding, a high-density compression molded product can be obtained by compression molding, and the oxygen absorption amount during storage etc. is reduced. Together with this, dimensional shrinkage in the subsequent sintering process can be minimized, so the dimensional accuracy as a sintered product can be significantly increased, and machining for dimensional adjustment after sintering can be minimized. It is possible, and in some cases, such dimensional adjustment is completely unnecessary. Moreover, there is little wear of the mold during compression molding, and segregation of the P component and the like does not occur, so that it is possible to obtain a sintered product with uniform physical properties.
【００１５】鋼粉中に含まれる燐（Ｐ）の総量は、特に
限定されるものではないが、軟質磁性材料として用いる
場合は、焼結の際の一般的温度１１００〜１２５０℃に
保持されている間にマトリックスを完全にα相化させる
という観点から、０．２重量％以上のＰ添加が望まし
い。しかしＰによる磁気特性改善の効果は、およそ１．
２重量％で飽和するから、添加するＰ分の上限は１．２
重量％とするのが望ましい。The total amount of phosphorus (P) contained in the steel powder is not particularly limited, but when used as a soft magnetic material, it is maintained at a general temperature of 1100 to 1250 ° C. during sintering. From the viewpoint of completely converting the matrix into the α phase during the heating, it is desirable to add 0.2% by weight or more of P. However, the effect of improving the magnetic characteristics by P is about 1.
Since it is saturated at 2% by weight, the upper limit of P content added is 1.2.
It is desirable to set it as the weight%.
【００１６】Ｐ分はＦｅ−Ｐ合金粉末として添加される
が、Ｆｅ−Ｐ合金粉末中のＰ量が少ない場合、上記鋼粉
末中のＰ分を所望量にするのに、硬質のＦｅ−Ｐ合金粉
末を多量添加しなければならなくなり、圧縮成形時に高
い圧粉体密度が得られ難くなる。反対にＰ含量の多いＦ
ｅ−Ｐ合金粉末を使用すると、添加重量（体積比）が少
なくなるために、純鉄粉とＦｅ−Ｐ合金粉末の接触点の
数が少なくなり、Ｐの均質な拡散及び寸法精度の確保が
困難となる。The P content is added as an Fe-P alloy powder, but when the P content in the Fe-P alloy powder is small, a hard Fe-P alloy is used to obtain the desired P content in the steel powder. Since a large amount of alloy powder must be added, it becomes difficult to obtain a high green compact density during compression molding. On the contrary, F with high P content
When the e-P alloy powder is used, the added weight (volume ratio) is reduced, so the number of contact points between the pure iron powder and the Fe-P alloy powder is reduced, and the uniform diffusion of P and the dimensional accuracy are ensured. It will be difficult.
【００１７】そこで本願発明者は、Ｆｅ−Ｐ合金粉末の
Ｐ含有量と平均粒径について検討した。その結果、寸法
精度を充分に確保するには、Ｆｅ−Ｐ合金に含有される
Ｐ濃度を１７〜２８重量％の範囲とし、かつ平均粒径を
６３μｍ以下とするのが良いとの結論を得た。上記の様
に規定することによって、寸法変化率の絶対値を調整す
ることができ、かつ寸法変化挙動に対する焼結温度への
鈍感さや成形体密度への鈍感さの度合いを任意に付与す
ることができ、結果として寸法精度に優れた焼結部品を
容易に得ることができたのである。Therefore, the inventor of the present application examined the P content and average particle size of the Fe-P alloy powder. As a result, in order to secure sufficient dimensional accuracy, it was concluded that the P concentration contained in the Fe-P alloy should be in the range of 17 to 28 wt% and the average particle size should be 63 μm or less. It was By defining as described above, the absolute value of the dimensional change rate can be adjusted, and the degree of insensitivity to the sintering temperature and the compact density to the dimensional change behavior can be arbitrarily given. As a result, a sintered part having excellent dimensional accuracy could be easily obtained.
【００１８】本発明の鋼粉を機械部品用に用いる場合の
ＣやＣｕの添加量は、所望する機械的性質に応じて適宜
組み合わせれば良いが、一般的にＣ：０．１〜１．０重
量％、Ｃｕ：０．５〜３．０重量％とするのが望まし
い。なお母材となる粉末冶金用鉄粉としては、アトマイ
ズ鉄粉、還元鉄粉、カーボニル鉄粉のいずれも採用する
ことができる。When the steel powder of the present invention is used for machine parts, the amount of C or Cu added may be appropriately combined depending on the desired mechanical properties, but generally C: 0.1-1. It is desirable that 0 wt% and Cu: 0.5 to 3.0 wt%. As the iron powder for powder metallurgy used as the base material, any of atomized iron powder, reduced iron powder, and carbonyl iron powder can be used.
【００１９】以下、実験例を挙げて本発明の構成および
作用効果をより具体的に説明する。 〈実験１〉 Ｆｅ−Ｐ合金粉末のＰ含有量について Ｐの供給源として、Ｐ含有量が１０．５〜２９重量％の
Ｆｅ−Ｐ合金粉末について調べた。本発明における焼結
部品の製造方法としては、アトマイズ法により得られた
平均粒径１００μｍの粉末冶金用鉄粉に、平均粒径６３
μｍのＦｅ−Ｐ合金粉末をＰ分が０．６重量％になる様
に配合し、更にバインダーとしてスチレン−ブタジエン
系溶液合成ゴムを２重量％と、潤滑剤としてステアリン
酸亜鉛０．７５重量％を混合し、乾燥させて混合粉を得
た。該混合粉を金型プレス形成で外径６４ｍｍ、内径２
４ｍｍ、厚さ１０ｍｍ、成形体密度６．９ｇ／ｃｍ3 の
リング状に成形した。その後メッシュベルト式焼結炉に
よりアンモニア分解ガス雰囲気中、１１８０℃で６０分
間の焼結を行なった。製造された焼結部品について、寸
法変化率、焼結体密度、外径寸法変化ばらつきＲ等を調
べた。図１に、寸法変化率（％）とＦｅ−Ｐ合金粉末中
のＰ濃度（重量％）の関係を示す。なお比較として、市
販の部分拡散型鋼粉から得られた焼結部品についての寸
法変化についても調べた。該市販の部分拡散型鋼粉と
は、Ｆｅ3 Ｐ組成のＦｅ−Ｐ合金粉末を微弱な熱処理に
よって純鉄粉表面に拡散接合させたものである。Hereinafter, the constitution and the working effects of the present invention will be described more specifically with reference to experimental examples. <Experiment 1> About P content of Fe-P alloy powder As a source of P, Fe-P alloy powder having a P content of 10.5 to 29 wt% was investigated. As a method for producing a sintered part in the present invention, an iron powder for powder metallurgy having an average particle size of 100 μm obtained by an atomizing method is used, and an average particle size of 63
Fe-P alloy powder of μm was mixed so that the P content would be 0.6% by weight, and 2% by weight of styrene-butadiene solution synthetic rubber as a binder and 0.75% by weight of zinc stearate as a lubricant. Were mixed and dried to obtain a mixed powder. The mixed powder is press-molded into a die with an outer diameter of 64 mm and an inner diameter of 2
It was molded into a ring shape having a thickness of 4 mm, a thickness of 10 mm, and a molded body density of 6.9 g / cm 3 . Thereafter, sintering was performed at 1180 ° C. for 60 minutes in an ammonia decomposition gas atmosphere in a mesh belt type sintering furnace. With respect to the manufactured sintered parts, the dimensional change rate, the sintered body density, the outer diameter dimensional change variation R, and the like were examined. FIG. 1 shows the relationship between the dimensional change rate (%) and the P concentration (% by weight) in the Fe—P alloy powder. As a comparison, the dimensional change of the sintered parts obtained from the commercially available partially diffused steel powder was also examined. The The commercial portion diffusion type steel powder, is obtained by diffusion bonding pure iron powder surface by weak heat-treating the Fe-P alloy powder Fe 3 P composition.
【００２０】図１から分かる様に、Ｆｅ−Ｐ合金粉末中
のＰ濃度が共晶組成であるＰ＝１０．５重量％又はＰ＝
２７重量％（図４参照）に近づくほど、寸法収縮量が大
きくなっている。これは焼結の初期段階において液相が
多量に生成するためと思われる。一方、市販の部分拡散
型鋼粉では特に著しい寸法収縮が見られる。これは市販
の部分拡散型では微弱な熱処理を行なうことによって共
晶組成のＰ濃度に近い部分拡散相が生じ、プレミックス
粉あるいはバインダーにより付着させたものよりも、よ
り早い段階で液相を生成するためと考えられる。As can be seen from FIG. 1, the P concentration in the Fe-P alloy powder is the eutectic composition P = 10.5% by weight or P =
The amount of dimensional shrinkage increases as it approaches 27% by weight (see FIG. 4). This is probably because a large amount of liquid phase was generated in the initial stage of sintering. On the other hand, the commercially available partial diffusion type steel powder shows a particularly remarkable dimensional shrinkage. This is because the commercially available partial diffusion type produces a partial diffusion phase close to the P concentration of the eutectic composition by performing a weak heat treatment, and produces a liquid phase at an earlier stage than that which is attached by a premix powder or a binder. It is thought to be to do.
【００２１】寸法精度を高めるには、焼結時における寸
法変化率の絶対値がなるべく小さい方が良い。しかし寸
法変化率の絶対値が小さい場合は、焼結時における密度
の向上が期待できないため、密度の充分な焼結部品を得
るには、金型プレス成形工程で密度を充分に上げておく
必要がある。In order to improve the dimensional accuracy, the absolute value of the dimensional change rate during sintering should be as small as possible. However, if the absolute value of the dimensional change rate is small, it is not possible to expect an improvement in the density during sintering. Therefore, in order to obtain a sintered part with a sufficient density, it is necessary to raise the density sufficiently in the die press molding process. There is.
【００２２】図２は、Ｆｅ−Ｐ合金粉末中のＰ濃度（重
量％）と圧縮性（成形体密度（ｇ／ｃｍ3 ）の関係を示
したグラフである。図２に見られる様に、Ｆｅ−Ｐ合金
粉末中のＰ濃度が低い場合は、圧縮性が低下している。
これはＰ濃度が低いと、添加するＦｅ−Ｐ合金粉末の重
量（体積比）が大きくなるからであると考えられる。良
好な磁気特性を得るためには、高密度のものを得る必要
があるので、できるだけ高濃度のＦｅ−Ｐ合金粉末を使
うことが望ましい。2 is a graph showing the relationship between the P concentration (% by weight) in the Fe-P alloy powder and the compressibility (molded body density (g / cm 3 ). As shown in FIG. When the P concentration in the Fe-P alloy powder is low, the compressibility is low.
It is considered that this is because when the P concentration is low, the weight (volume ratio) of the Fe—P alloy powder to be added becomes large. In order to obtain good magnetic properties, it is necessary to obtain a high density, so it is desirable to use Fe-P alloy powder with the highest possible concentration.
【００２３】図３は、Ｆｅ−Ｐ合金粉末中のＰ濃度（重
量％）と寸法精度（外径寸法変化ばらつきＲ（ｍｍ））
の関係を示したグラフである。グラフ縦軸の外径寸法の
変化のばらつきＲとは、自動成形プレスで１０００個の
リング状試験片を成形・焼結した後の、外径寸法の最大
値と最小値の差である。図３から分かる様に、Ｐ含有量
が低い場合及び２８重量％以上の場合、外径寸法変化の
ばらつきＲは大きくなる。FIG. 3 shows the P concentration (% by weight) in the Fe-P alloy powder and the dimensional accuracy (variation in outer diameter dimensional change R (mm)).
It is a graph showing the relationship of. The variation R in the change of the outer diameter dimension on the vertical axis of the graph is the difference between the maximum value and the minimum value of the outer diameter dimension after molding and sintering 1000 ring-shaped test pieces by an automatic molding press. As can be seen from FIG. 3, when the P content is low and when it is 28% by weight or more, the variation R of the outer diameter dimensional change becomes large.
【００２４】上述の様に高密度のものを得るには、Ｐが
高濃度のＦｅ−Ｐ合金粉末を用いるのがよいが、このよ
うな合金粉末を使用した場合、外径寸法変化のばらつき
Ｒが大きくなって不適当となる。これはＰが高濃度のＦ
ｅ−Ｐ合金粉末を使った場合、Ｐ分の分散が不十分とな
るからである。In order to obtain a high density as described above, it is preferable to use a Fe-P alloy powder having a high P concentration. When such an alloy powder is used, the variation R in the outer diameter dimensional change is R. Becomes large and unsuitable. This is F with high P concentration
This is because when the e-P alloy powder is used, the P content is insufficiently dispersed.
【００２５】以上の検討から、焼結時の寸法変化率の絶
対値が小さく、成形時に十分高い成形体密度が得られ、
かつ寸法変化ばらつきを小さくできるもの、即ち寸法精
度を確保し且つ最終的に高密度焼結体を得ることのでき
るＦｅ−Ｐ合金粉末は、Ｐ含有量が１７重量％〜２８重
量％の範囲であるとの知見を得た。From the above examination, the absolute value of the dimensional change rate during sintering is small, and a sufficiently high compact density can be obtained during compacting.
Moreover, the Fe-P alloy powder that can reduce the variation in dimensional change, that is, secure the dimensional accuracy and finally obtain the high-density sintered body, has a P content in the range of 17% by weight to 28% by weight. I got the knowledge that there is.
【００２６】〈実験２〉 Ｆｅ−Ｐ合金粉末の平均粒度
について Ｐを２６．９重量％含有するＦｅ−Ｐ合金を用い、粉砕
或はふるい条件を変化させることによって１０〜１５０
μｍの夫々の平均粒度を持つＦｅ−Ｐ合金粉末を得、実
験に使用した。焼結部品の製造方法としては、上記実験
１と同様に、Ｐ含有量が０．６重量％になる様にＦｅ−
Ｐ合金粉末を粉末冶金用純鉄粉に添加し、バインダーと
してスチレン−ブタジエン系溶液合成ゴム、及び潤滑材
としてステアリン酸亜鉛を混合し乾燥させて混合粉を
得、該混合粉を金型プレス成形でリング状に成形した
後、焼結を行なった。得られた焼結部品について、外径
寸法変化ばらつき、外径寸法変化率及び成形体密度を調
べた。<Experiment 2> Average particle size of Fe-P alloy powder 10-150 by using a Fe-P alloy containing 26.9% by weight of P and changing grinding or sieving conditions.
Fe-P alloy powders with respective average particle size of μm were obtained and used for the experiments. As in the case of Experiment 1 above, as a method for producing a sintered part, Fe--
P alloy powder is added to pure iron powder for powder metallurgy, styrene-butadiene solution synthetic rubber as a binder, and zinc stearate as a lubricant are mixed and dried to obtain a mixed powder, which is press-molded with a mold. After being molded into a ring shape with, sintering was performed. The obtained sintered parts were examined for variation in outer diameter dimension change, outer diameter dimension change rate, and compact density.
【００２７】図５は、Ｆｅ−Ｐ合金粉末粒度（μｍ）と
寸法精度（外径寸法変化ばらつきＲ（ｍｍ））の関係を
示すグラフである。図５から分かる様に、Ｆｅ−Ｐ合金
粉末粒度が６３μｍ以上になると、寸法精度の確保が困
難になっている。これはＰの分散が不十分になるからで
ある。FIG. 5 is a graph showing the relationship between the Fe-P alloy powder particle size (μm) and the dimensional accuracy (outer diameter dimensional change variation R (mm)). As can be seen from FIG. 5, when the grain size of the Fe—P alloy powder is 63 μm or more, it becomes difficult to secure dimensional accuracy. This is because the dispersion of P becomes insufficient.
【００２８】図６は、Ｆｅ−Ｐ合金粉末粒度（μｍ）と
外径寸法変化率（％）及び成形体密度（ｇ／ｃｍ3 ）の
関係を示すグラフである。尚Ｆｅ−Ｐ合金粉末粒度は、
比較例１：１０７μｍ、比較例２：７５μｍ、実施例
１：６３μｍ、実施例２：４５μｍ、実施例３：３０μ
ｍである。図６から分かる様に、Ｆｅ−Ｐ合金粉末の粒
度が微細になるほど寸法変化率の密度依存性は弱く且つ
絶対値が小さくなる。従って、微細なＦｅ−Ｐ合金粉末
を使用すれば、実際の焼結部品製造において、成形体の
密度のばらつきに起因する寸法不良を小さくすることが
できる。特に６３μｍ以下の微細なＦｅ−Ｐ合金粉末
（例えば実施例１〜３）では、粒度の差が寸法変化率に
及ぼす影響が非常に小さくなるから、混合粉製造過程に
おいて不可避である粉末の破砕現象を無視でき、混合粉
のロット間における寸法変化率を安定させることが容易
となる。FIG. 6 is a graph showing the relationship among the Fe-P alloy powder particle size (μm), outer diameter dimensional change rate (%), and compact density (g / cm 3 ). The particle size of the Fe-P alloy powder is
Comparative Example 1: 107 μm, Comparative Example 2: 75 μm, Example 1: 63 μm, Example 2: 45 μm, Example 3:30 μm
m. As can be seen from FIG. 6, the finer the grain size of the Fe—P alloy powder, the weaker the density dependence of the dimensional change rate and the smaller the absolute value. Therefore, if the fine Fe-P alloy powder is used, it is possible to reduce the dimensional defect due to the variation in the density of the compact in the actual production of the sintered part. In particular, in the case of fine Fe-P alloy powders of 63 μm or less (for example, Examples 1 to 3), the influence of the difference in particle size on the dimensional change rate becomes very small, so the crushing phenomenon of powder which is inevitable in the mixed powder manufacturing process. Can be ignored, and it becomes easy to stabilize the dimensional change rate between lots of the mixed powder.
【００２９】〈実験３〉 焼結炉中の温度分布及び成形
体内部の温度勾配について 実際の焼結部品製造工程においては、原料粉におけるＰ
の偏析と共に焼結炉中の温度分布及び成形体内部の温度
勾配が、寸法精度不良の原因となっている。そこで本発
明者は焼結温度の寸法変化率に及ぼす影響を検討した。
実験には、Ｐ含量が１７〜２８重量％のＦｅ−Ｐ合金粉
末（平均粒径４５μｍ）を用い、Ｐ分が１重量％になる
よう粉末冶金用純鉄粉に配合し、スチレン−ブタジエン
系溶液合成ゴム（バインダー）にて付着させ、これにつ
いて焼結温度に対する寸法変化率を調べた。また比較例
として、Ｆｅ−Ｐ合金粉末を粉末冶金用純鉄粉の表面に
バインダーにより拡散付着させたものについても調べ
た。各実施例及び比較例のＰ含量、焼結温度条件を下記
表１に示す。<Experiment 3> Regarding Temperature Distribution in Sintering Furnace and Temperature Gradient in Formed Body In the actual manufacturing process of the sintered part, P in the raw material powder was used.
In addition to the segregation of No. 2, the temperature distribution in the sintering furnace and the temperature gradient inside the molded body are the causes of poor dimensional accuracy. Therefore, the present inventor examined the influence of the sintering temperature on the dimensional change rate.
In the experiment, Fe-P alloy powder having a P content of 17 to 28% by weight (average particle diameter 45 μm) was mixed with pure iron powder for powder metallurgy so that the P content was 1% by weight, and a styrene-butadiene system was used. The solution synthetic rubber (binder) was used for the adhesion, and the dimensional change rate with respect to the sintering temperature was examined. In addition, as a comparative example, a Fe-P alloy powder was also examined by diffusing and adhering it onto the surface of pure iron powder for powder metallurgy with a binder. Table 1 below shows the P content and the sintering temperature conditions of each Example and Comparative Example.
【００３０】[0030]
【表１】 [Table 1]
【００３１】図７は、Ｆｅ−Ｐ合金粉末中のＰ濃度と外
径寸法変化率（％）及び成形体密度（ｇ／ｃｍ3 ）の関
係を表すグラフであり、Ｆｅ−Ｐ合金粉末中のＰ含有量
が１７重量％〜２１．７重量％（Ｆｅ2 Ｐ組成，図４の
状態図参照）の範囲における特性を示すものとしてＰ＝
１８．３％のもの（実施例４，６）、同様に２１．７重
量％〜２８重量％の範囲における特性を示すものとして
Ｐ＝２６．９％のもの（実施例５，７）をプロットして
いる。尚グラフ中の比較例３，４はＦｅ−Ｐ合金粉末中
のＰ含有量が１６．５重量％のものを鉄粉表面に部分拡
散付着させたものである。FIG. 7 is a graph showing the relationship between the P concentration in the Fe-P alloy powder, the outer diameter dimensional change rate (%), and the compact density (g / cm 3 ). P = 17% by weight to 21.7% by weight (Fe 2 P composition, see the state diagram of FIG. 4) as a characteristic showing P =
Plots of 18.3% (Examples 4 and 6) and P = 26.9% (Examples 5 and 7) showing characteristics in the range of 21.7% to 28% by weight. is doing. In Comparative Examples 3 and 4 in the graph, Fe-P alloy powder having a P content of 16.5% by weight was partially diffused and adhered to the surface of the iron powder.
【００３２】本実験３より、Ｆｅ−Ｐ合金粉末中のＰ含
有量が１７重量％〜２１．７重量％（Ｆｅ2 Ｐ組成）の
ものをＰ供給源として使用した場合は、焼結温度の変動
による寸法変化率の変化がきわめて小さくなることが分
かる。一方、Ｐ含有量が２１．７〜２８重量％のＦｅ−
Ｐ合金粉末を使用した場合には、寸法変化率の成形体密
度依存性が小さくなるとの知見を得た。この現象は図４
に示すＦｅ−Ｐ２元系状態図においてＦｅ2 Ｐ組成（Ｐ
＝２１．７重量％）で液相線が変曲点を持つ、すなわち
ポテンシャルエネルギーの変化（しきい）があること
が、焼結時の寸法変化挙動に特徴的な差として現れたも
のである。According to the present Experiment 3, when the P content in the Fe-P alloy powder is 17 wt% to 21.7 wt% (Fe 2 P composition) is used as the P supply source, the sintering temperature It can be seen that the change in the dimensional change rate due to the change is extremely small. On the other hand, Fe-containing P of 21.7 to 28 wt%
It was found that when the P alloy powder was used, the dependency of the dimensional change rate on the compact density was reduced. This phenomenon is shown in Figure 4.
In the Fe-P binary system phase diagram shown in Fig. 2 , the Fe 2 P composition (P
= 21.7% by weight), the liquidus line has an inflection point, that is, a potential energy change (threshold) appears as a characteristic difference in dimensional change behavior during sintering. .
【００３３】従って、焼結温度の変化に鈍感な鋼粉を得
るためには、Ｐ含有量が１７〜２１．７重量％のＦｅ−
Ｐ合金粉末を使用すれば良く、成形体密度に鈍感な鋼粉
を得るためにはＰ含有量が２１．７〜２８重量％のＦｅ
−Ｐ合金粉末を使用すれば良い。また２種以上のＰ含有
量の異なるＦｅ−Ｐ合金を組み合わせて使用すること
で、所望の寸法変化挙動に応じたものとすることもでき
る。あるいは成形体部位ごとにＰ含有量の異なるＦｅ−
Ｐ合金を使用した鋼粉を使い、数値制御式プレスを用い
て寸法精度の改善を行なうことや、同一組成材料で寸法
変化率の差を利用した焼結接合を行なうこともできる。Therefore, in order to obtain a steel powder which is insensitive to changes in the sintering temperature, Fe-containing P of 17 to 21.7% by weight is used.
It is sufficient to use P alloy powder, and in order to obtain steel powder that is insensitive to the compact density, Fe having a P content of 21.7 to 28 wt% is used.
-P alloy powder may be used. Further, by using two or more kinds of Fe-P alloys having different P contents in combination, it is possible to obtain a desired dimensional change behavior. Alternatively, Fe- having a different P content for each molded body site
It is also possible to improve the dimensional accuracy by using a numerical control type press using steel powder using P alloy, or to perform sinter bonding using the difference in dimensional change rate with the same composition material.
【００３４】Ｆｅ−Ｐ合金粉末中のＰ濃度が寸法変化挙
動に影響を及ぼす原因としては、Ｐの純Ｆｅ中への拡
散とそれに伴う液相生成のタイミングの差、図４の状
態図に示されるようにＦｅ2 Ｐ組成（２１．７重量％
Ｐ）で活性化エネルギーが最大となること、またＦｅ
−Ｐ合金粉末と純鉄粉の接触点数（Ｐの分散状態）の差
が考えられ、これは局所に生成する液相量の多少に影響
しているからであると推察される。The reason why the P concentration in the Fe-P alloy powder influences the dimensional change behavior is that the difference between the diffusion of P into pure Fe and the accompanying timing of liquid phase formation is shown in the state diagram of FIG. Fe 2 P composition (21.7 wt%
P) has the maximum activation energy, and Fe
A difference in the number of contact points (dispersion state of P) between the -P alloy powder and the pure iron powder is considered, and it is presumed that this influences the amount of locally generated liquid phase.
【００３５】〈実験４〉 鋼粉の見掛密度、流動度、金
型損耗について 薄肉・複雑形状部品に供せられる鋼粉には、高い見掛密
度と良好な流れ性（流動度）が必要である。また、焼結
部品の製造においてコストに大きく影響する金型の損耗
が少ないこと、即ち金型攻撃性の少ないことも必要とさ
れる。<Experiment 4> Apparent Density, Flowability, and Die Wear of Steel Powder Steel powder used for thin-walled and complex-shaped parts must have high apparent density and good flowability (fluidity). Is. Further, it is also required that the die wear, which greatly affects the cost in the production of the sintered parts, is small, that is, the die aggression is small.
【００３６】そこで本実験４ではバインダーを添加して
得た実施例８〜１２の鋼粉、及び比較例５〜９のプレミ
ックスの鋼粉（前記従来法による）、比較例１０の部分
拡散型の鋼（前記従来法による）についての見掛密度、
流動度、金型損耗を調べた。尚、本発明の実施例８〜１
２の鋼粉を得る方法は、下記表２に示す夫々のＰ含有量
のＦｅ−Ｐ合金粉末を用いて、Ｐ分が１．２重量％とな
る様に粉末冶金用純鉄粉に配合し、バインダーのスチレ
ン−ブタジエン系溶液合成ゴムを用いて付着させること
により得た。表２に夫々実施例、比較例の混合粉の粉体
特性の結果を示す。Therefore, in Experiment 4, the steel powders of Examples 8 to 12 obtained by adding a binder, the premixed steel powders of Comparative Examples 5 to 9 (according to the conventional method), and the partial diffusion type of Comparative Example 10 were used. Apparent density of steel (according to the conventional method),
The fluidity and die wear were examined. In addition, Examples 8 to 1 of the present invention
The method for obtaining the steel powder of No. 2 is to use Fe-P alloy powders having the respective P contents shown in Table 2 below, and mix them with pure iron powder for powder metallurgy so that the P content is 1.2% by weight. , A styrene-butadiene-based solution as a binder, and a synthetic rubber. Table 2 shows the results of the powder characteristics of the mixed powders of Examples and Comparative Examples, respectively.
【００３７】[0037]
【表２】 [Table 2]
【００３８】表２から分かる様に、比較例５〜１０と異
なり、実施例８〜１２では見掛密度、流動度、金型損耗
において良好である。これは、実施例８〜１２では硬質
のＦｅ−Ｐ合金粉末がバインダーによりコーティングさ
れており、また純鉄粉表面に付着・造粒されているから
であり、従って見掛密度が高く、流動性及び金型損耗が
改善されるのである。As can be seen from Table 2, unlike Comparative Examples 5 to 10, Examples 8 to 12 are good in apparent density, fluidity and die wear. This is because in Examples 8 to 12, the hard Fe-P alloy powder is coated with the binder, and the pure Fe powder is adhered and granulated on the surface of the powder. Therefore, the apparent density is high and the fluidity is high. And the die wear is improved.
【００３９】図８は、成形体密度と抜出圧力の関係を示
したグラフであり、金型への負荷を評価する尺度とな
る。図８から分かる様に、本発明の鋼粉では同一成形体
密度を得るのに要する抜出圧力が約３０ｋｇ／ｃｍ2 改
善され、金型損耗の防止に効果的である。FIG. 8 is a graph showing the relationship between the compact density and the ejection pressure, which is a scale for evaluating the load on the mold. As can be seen from FIG. 8, with the steel powder of the present invention, the extraction pressure required to obtain the same compact density is improved by about 30 kg / cm 2 , which is effective in preventing die wear.
【００４０】〈実験５〉焼結時の寸法変化率に鋼粉の酸
素量が影響するから、鋼粉中の酸素の経時変化を調べ
た。図９は、製造後日数と酸素増加量の関係を示すグラ
フである。本発明に係る鋼粉（実施例１５）は、粉末冶
金用純鉄粉にＦｅ−Ｐ合金粉末をＰ分が１重量％になる
ように添加し、スチレン−ブタジエン系溶液合成ゴムの
バインダーとともに混合する方法により得た。比較例１
２の鋼粉としては、Ｐ分１重量％を粉末冶金用純鉄粉表
面に拡散付着された鋼粉とステアリン亜鉛０．７５重量
％との混合粉を用いた。図９から分かる様に、発明例１
５の１２０日後の酸素増加量は、ステアリン酸亜鉛を混
合した比較例１２の１／１０である。<Experiment 5> Since the amount of oxygen in the steel powder affects the dimensional change rate during sintering, the change over time in oxygen in the steel powder was investigated. FIG. 9 is a graph showing the relationship between the number of days after production and the oxygen increase amount. In the steel powder according to the present invention (Example 15), Fe—P alloy powder was added to pure iron powder for powder metallurgy so that the P content was 1% by weight, and mixed with a binder of styrene-butadiene solution synthetic rubber. It was obtained by the method. Comparative Example 1
As the steel powder of No. 2, a mixed powder of steel powder obtained by diffusing and adhering P content of 1% by weight on the surface of pure iron powder for powder metallurgy and 0.75% by weight of zinc stearate was used. As can be seen from FIG. 9, invention example 1
The amount of increase in oxygen after 120 days of 5 is 1/10 of that of Comparative Example 12 in which zinc stearate was mixed.
【００４１】本発明に係る鋼粉は易酸化性のＦｅ−Ｐ合
金粉末がバインダーによりコーティングされるため、大
気と遮断されて酸素量の経時変化が非常に少なくなり、
発錆を抑えられる。この効果は粉末冶金法で一般的に用
いられるＣｕ、Ｎｉ、Ｍｏ、Ｃｒ、Ｍｎ、Ｓｉの粉末及
びこれらの元素とＦｅとの合金粉末の場合にも同様であ
る。In the steel powder according to the present invention, since the easily oxidizable Fe-P alloy powder is coated with the binder, the steel powder is shielded from the atmosphere and the change in oxygen amount with time is extremely reduced.
Can prevent rusting. This effect is the same also in the case of powders of Cu, Ni, Mo, Cr, Mn, and Si which are generally used in powder metallurgy, and alloy powders of these elements and Fe.
【００４２】〈実験６〉実験６では焼結温度の寸法変化
率に及ぼす影響を検討した。本発明の鋼粉としては、Ｐ
含有量が１７〜２８重量％のＦｅ−Ｐ合金粉末（平均粒
径４５μｍ）を、Ｐ分を１重量％になるよう粉末冶金用
純鉄粉に配合し、Ｃｕ粉末１．５重量％、Ｃ粉末０．４
重量％とともに、スチレン−ブタジエン系溶液合成ゴム
のバインダーで粉末冶金用純鉄粉表面に付着させて得
た。比較例の鋼粉としては、Ｆｅ−Ｐ合金粉末を粉末冶
金用純鉄粉の表面に拡散付着されたものを用いた。尚下
記表３に実施例、比較例についてのＦｅ−Ｐ合金粉末の
Ｐ含有量、及び焼結温度の条件を示す。<Experiment 6> In Experiment 6, the influence of the sintering temperature on the dimensional change rate was examined. The steel powder of the present invention includes P
Fe-P alloy powder having a content of 17 to 28% by weight (average particle diameter 45 μm) was mixed with pure iron powder for powder metallurgy so that the P content was 1% by weight, and Cu powder was 1.5% by weight, C Powder 0.4
It was obtained by adhering to the surface of pure iron powder for powder metallurgy with a binder of styrene-butadiene-based solution synthetic rubber together with the weight percentage. As the steel powder of the comparative example, the one obtained by diffusing and depositing the Fe-P alloy powder on the surface of the pure iron powder for powder metallurgy was used. Table 3 below shows the conditions for the P content of the Fe-P alloy powder and the sintering temperature for Examples and Comparative Examples.
【００４３】[0043]
【表３】 [Table 3]
【００４４】図１０から分かる様に、実施例１６〜１９
の鋼粉は寸法変化率の密度依存性が比較例１３、１４に
比べて小さく、Ｐ含有量が１７〜２１．７重量％のＦｅ
−Ｐ合金粉末では特に焼結温度の変化に対して鈍感であ
った。As can be seen from FIG. 10, Examples 16-19
Of the steel powder, the density dependency of the dimensional change rate was smaller than that of Comparative Examples 13 and 14, and the P content was 17 to 21.7 wt% Fe.
The -P alloy powder was particularly insensitive to changes in the sintering temperature.
【００４５】[0045]
【発明の効果】以上の様に本発明に係る粉末冶金用鉄−
燐糸鋼粉は、鋼粉の輸送の際等の偏析を抑制することが
でき、又鋼粉の見掛密度と流動性が改善されて、たとえ
薄肉・複雑形状部品の金型成形においても、Ｐ成分等の
偏析のない高密度の圧縮成形体を得ることができ、その
後の焼結工程での寸法収縮が抑えられて寸法精度の高い
焼結製品を与える。更に金型の損耗も抑制される。従っ
て本発明の鋼粉を用いた焼結部品は、寸法精度の確保が
容易で良好な磁気特性や機械的強度を発現できる。As described above, the iron for powder metallurgy according to the present invention-
Phosphorus steel powder can suppress segregation during transportation of steel powder, and also improves the apparent density and fluidity of steel powder, making it possible to mold even thin-walled and complex-shaped parts. It is possible to obtain a high-density compression-molded product without segregation of the P component and the like, and to suppress the dimensional shrinkage in the subsequent sintering step to provide a sintered product with high dimensional accuracy. Further, wear of the mold is also suppressed. Therefore, the sintered part using the steel powder of the present invention can easily secure dimensional accuracy and can exhibit good magnetic properties and mechanical strength.
【図面の簡単な説明】[Brief description of drawings]
【図１】Ｆｅ−Ｐ合金粉末中のＰ濃度と寸法変化率の関
係を示すグラフ。FIG. 1 is a graph showing the relationship between the P concentration in Fe—P alloy powder and the dimensional change rate.
【図２】Ｆｅ−Ｐ合金粉末中のＰ濃度と圧縮性の関係を
示すグラフ。FIG. 2 is a graph showing the relationship between P concentration in Fe—P alloy powder and compressibility.
【図３】Ｆｅ−Ｐ合金粉末中のＰ濃度と寸法精度の関係
を示すグラフ。FIG. 3 is a graph showing the relationship between P concentration in Fe—P alloy powder and dimensional accuracy.
【図４】Ｆｅ−Ｐの２元状態図。FIG. 4 is a binary phase diagram of Fe—P.
【図５】Ｆｅ−Ｐ合金粉末の粒度と寸法精度の関係を示
すグラフ。FIG. 5 is a graph showing the relationship between particle size and dimensional accuracy of Fe—P alloy powder.
【図６】Ｆｅ−Ｐ合金粉末の粒度と寸法変化率の関係を
示すグラフ。FIG. 6 is a graph showing the relationship between the grain size of Fe—P alloy powder and the dimensional change rate.
【図７】Ｆｅ−Ｐ合金粉末中のＰ濃度と寸法変化率の関
係を示すグラフ。FIG. 7 is a graph showing the relationship between the P concentration in the Fe—P alloy powder and the dimensional change rate.
【図８】成形体密度と抜出圧力の関係を示すグラフ。FIG. 8 is a graph showing the relationship between the compact density and the ejection pressure.
【図９】混合粉中の酸素の経時変化を示すグラフ。FIG. 9 is a graph showing changes with time of oxygen in the mixed powder.
【図１０】Ｆｅ−Ｐ合金粉中のＰ濃度と寸法変化率の関
係を示すグラフ。FIG. 10 is a graph showing the relationship between the P concentration in the Fe—P alloy powder and the dimensional change rate.
Claims (4)
が６３μｍ以下の鉄−燐合金粉末を、バインダーによっ
て粉末冶金用鉄粉表面に付着させたものであることを特
徴とする粉末冶金用鉄−燐系鋼粉。1. A powder characterized in that an iron-phosphorus alloy powder having a phosphorus content of 17 to 28% by weight and an average particle diameter of 63 μm or less is adhered to the surface of iron powder for powder metallurgy by a binder. Iron-phosphorus steel powder for metallurgy.
６３μｍ以下の鉄−燐合金粉末と、炭素粉末及び／又は
銅粉末とを、バインダーによって粉末冶金用鉄粉表面に
付着させたものであることを特徴とする粉末冶金用鉄−
燐系鋼粉。2. An iron-phosphorus alloy powder having a phosphorus content of 17 to 28% by weight and an average particle size of 63 μm or less, and carbon powder and / or copper powder are attached to the surface of iron powder for powder metallurgy by a binder. Iron for powder metallurgy characterized by being
Phosphorous steel powder.
が６３μｍ以下の鉄−燐合金粉末と、バインダーと、粉
末冶金用鉄粉とを、潤滑材と共に混合して成形し、焼結
することを特徴とする焼結部品の製造方法。3. An iron-phosphorus alloy powder having a phosphorus content of 17 to 28% by weight and an average particle size of 63 μm or less, a binder, and an iron powder for powder metallurgy are mixed together with a lubricant, molded, and fired. A method for manufacturing a sintered part, which comprises tying.
が６３μｍ以下の鉄−燐合金粉末と、炭素粉末及び／ま
たは銅粉末と、バインダーと、粉末冶金用鉄粉とを、潤
滑材と共に混合して成形し、焼結することを特徴とする
焼結部品の製造方法。4. Lubricating an iron-phosphorus alloy powder having a phosphorus content of 17 to 28% by weight and an average particle size of 63 μm or less, carbon powder and / or copper powder, a binder, and iron powder for powder metallurgy. A method for producing a sintered part, which comprises mixing the material with a material, molding the material, and sintering the material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5350316A JPH07197101A (en) | 1993-12-29 | 1993-12-29 | Iron-phosphorus steel powder for powder metallurgy and production of sintered parts |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5350316A JPH07197101A (en) | 1993-12-29 | 1993-12-29 | Iron-phosphorus steel powder for powder metallurgy and production of sintered parts |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07197101A true JPH07197101A (en) | 1995-08-01 |
Family
ID=18409666
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5350316A Pending JPH07197101A (en) | 1993-12-29 | 1993-12-29 | Iron-phosphorus steel powder for powder metallurgy and production of sintered parts |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07197101A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102649156A (en) * | 2012-03-09 | 2012-08-29 | 成都邦普合金材料有限公司 | Method for adding hard alloy mixture paraffin wax shaping agent |
| CN102921943A (en) * | 2012-10-30 | 2013-02-13 | 南通金巨霸机械有限公司 | Powder metallurgy mechanical part production process |
| CN104550910A (en) * | 2014-12-25 | 2015-04-29 | 铜陵市经纬流体科技有限公司 | Easily radiating powder metallurgy material for valve and preparation method of material |
-
1993
- 1993-12-29 JP JP5350316A patent/JPH07197101A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102649156A (en) * | 2012-03-09 | 2012-08-29 | 成都邦普合金材料有限公司 | Method for adding hard alloy mixture paraffin wax shaping agent |
| CN102921943A (en) * | 2012-10-30 | 2013-02-13 | 南通金巨霸机械有限公司 | Powder metallurgy mechanical part production process |
| CN104550910A (en) * | 2014-12-25 | 2015-04-29 | 铜陵市经纬流体科技有限公司 | Easily radiating powder metallurgy material for valve and preparation method of material |
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