JPH0375621B2 - - Google Patents
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- Publication number
- JPH0375621B2 JPH0375621B2 JP7229189A JP7229189A JPH0375621B2 JP H0375621 B2 JPH0375621 B2 JP H0375621B2 JP 7229189 A JP7229189 A JP 7229189A JP 7229189 A JP7229189 A JP 7229189A JP H0375621 B2 JPH0375621 B2 JP H0375621B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- less
- density
- sintered
- alloy
- 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.)
- Expired
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- 239000000843 powder Substances 0.000 claims description 43
- 229910045601 alloy Inorganic materials 0.000 claims description 36
- 239000000956 alloy Substances 0.000 claims description 36
- 238000004663 powder metallurgy Methods 0.000 claims description 22
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 17
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 238000005245 sintering Methods 0.000 claims description 13
- 229910052698 phosphorus Inorganic materials 0.000 claims description 11
- 229910052748 manganese Inorganic materials 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 10
- 239000012535 impurity Substances 0.000 claims description 9
- 229910052799 carbon Inorganic materials 0.000 claims description 8
- 238000002156 mixing Methods 0.000 claims description 7
- 229910052750 molybdenum Inorganic materials 0.000 claims description 7
- 229910052721 tungsten Inorganic materials 0.000 claims description 6
- 229910052710 silicon Inorganic materials 0.000 claims description 5
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 239000011572 manganese Substances 0.000 description 15
- 239000011651 chromium Substances 0.000 description 11
- 230000000694 effects Effects 0.000 description 9
- 238000012360 testing method Methods 0.000 description 9
- 230000005496 eutectics Effects 0.000 description 8
- 239000000523 sample Substances 0.000 description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 7
- 239000010955 niobium Substances 0.000 description 7
- 238000000227 grinding Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 229910052758 niobium Inorganic materials 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 229910052720 vanadium Inorganic materials 0.000 description 5
- VAKIVKMUBMZANL-UHFFFAOYSA-N iron phosphide Chemical compound P.[Fe].[Fe].[Fe] VAKIVKMUBMZANL-UHFFFAOYSA-N 0.000 description 4
- 239000007791 liquid phase Substances 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 239000007921 spray Substances 0.000 description 4
- 229910052804 chromium Inorganic materials 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 238000000465 moulding Methods 0.000 description 3
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 150000001247 metal acetylides Chemical class 0.000 description 2
- 238000001000 micrograph Methods 0.000 description 2
- 239000011733 molybdenum Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 238000010301 surface-oxidation reaction Methods 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910017060 Fe Cr Inorganic materials 0.000 description 1
- 229910002544 Fe-Cr Inorganic materials 0.000 description 1
- 229910017108 Fe—Fe Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- UPHIPHFJVNKLMR-UHFFFAOYSA-N chromium iron Chemical compound [Cr].[Fe] UPHIPHFJVNKLMR-UHFFFAOYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000009689 gas atomisation Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 235000013372 meat Nutrition 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 238000013001 point bending Methods 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
Description
（技術分野）
本発明は、高密度高強度焼結体の製造法に係
り、特に高密度、高強度の焼結体を与え得る粉末
冶金用合金粉末を用いて、焼結体を製造する方法
に関するものである。
（背景技術）
金属粉末から、粉末冶金手法によつて成形し、
焼結して得られる焼結部品（焼結体）に関して、
近年、その適用分野の拡大には著しいものがあ
り、とりわけ液相を利用した高密度焼結技術の発
展により、高強度部品の分野への進出には目覚ま
しいものがある。
そして、従来から、かかる高強度部品への進出
を目指したCr系ステンレス鋼粉末を用いる粉末
冶金では、Ｃ及びＰの同時添加による燐化鉄共晶
（Fe−Fe3C−Fe3P）の液相を利用して焼結密度
を向上させ、加えてその共晶部分が高硬度である
ところから、その耐磨耗性を著しく向上させてい
る。そして、このような手法によつて、工業的に
は密度比で約93％程度のものまでの焼結体の製造
が可能となり、比較的高密度な耐磨耗部品、例え
ば自動車のエンジン回りの摺動部材、食肉機械部
品（カツター）等への適用が図られてきている。
しかしながら、粉末冶金手法によつて得られる
焼結部品の適用分野の更なる拡大には、より一層
の性能向上が必要であり、このため高密度、高強
度を具備した焼結部品の開発、更にはかかる焼結
部品を製造する手法の開発が望まれているのであ
る。ところで、周知のように、焼結部品の強度は
主に(a)基地の強度、(b)密度比の影響を受け、そし
て基地の強度が高い程、また密度も高い程、得ら
れる焼結体の強度は向上されることとなるのであ
る。
（解決課題）
ここにおいて、本発明は、得られる焼結体の密
度の向上、ひいてはその強度の向上が図られ得る
製造法を提供することを、その目的とするもので
あつて、このため、かかる焼結体を製造するため
に用いられる粉末冶金用合金粉末において、従来
からのＣ、Ｐの添加に加えて、更にMnをも必須
元素として添加しようとするものであり、これ
は、本発明者等が詳細な実験を繰り返した結果、
成形圧力や焼結温度等の製造条件が同じである同
一工程で製造した場合に、Mnの添加によつて得
られる焼結体の密度が明らかに向上される知見を
得たことに基づくものである。
（解決手段）
すなわち、本発明は、Cr（クロム）：7.0〜30.0
％、Mn（マンガン）：0.1〜1.5％、Ｐ（燐）：0.1〜
1.0％、残部：Fe（鉄）及び不可避的不純物からな
る粉末冶金用合金粉末を用い、これに対して0.5
〜5.0％の割合の炭素粉末を添加、配合して、焼
結せしめることを、その要旨とするものである。
また、本発明にあつては、Cr：7.0〜30.0％、
Mn：0.1〜1.5％、Ｐ：0.1〜1.0％、Ｃ（炭素）：0.1
％以下、Si（珪素）：0.1〜4.0％、残部：Fu及び不
可避的不純物からなる粉末冶金用合金粉末を用
い、これに対して0.5〜5.0％の割合の炭素粉末を
添加、配合して、焼結せしめることをも、その特
徴とするものである。
さらに、本発明は、Cr：7.0〜30.0％と、Mn：
0.1〜1.5％と、Ｐ：0.1〜1.0％と、5.0％以下のMo
（モリブデン）、5.0％以下のＷ（タングステン）、
3.0％以下のＶ（バナジウム）及び5.0％以下のNb
（ニオブ）のうちから選ばれた１種若しくは２種
以上の元素の合計の含有量で10％以下と、残部：
Fe及び不可避的不純物とからなる粉末冶金用合
金粉末を用い、これに対して0.5〜5.0％の割合の
炭素粉末を添加、配合して、焼結せしめること
を、その特徴とするものである。
更にまた、本発明は、Cr：7.0〜30.0％と、
Mn：0.1〜1.5％と、Ｐ：0.1〜1.0％と、Ｃ：0.1％
以下と、Si：0.1〜4.0％と、5.0％以下のMo、5.0
％以下のＷ、3.0％以下のＶ及び5.0％以下のNbの
うちから選ばれた１種若しくは２種以上の元素の
合計の含有量で10％以下と、残部：Fe及び不可
避的不純物とからなる粉末冶金用合金粉末を用
い、これに対して0.5〜5.0％の割合の炭素粉末を
添加、配合して、焼結せしめることをも、その特
徴とするものである。
（具体的構成）
ところで、かかる本発明において用いられる粉
末冶金用合金粉末は、7.0〜30.0％のCrと、0.1〜
1.5％のMnと、0.1〜1.0％のＰとを主要合金成分
として含み、残部がFe及び不可避的不純物から
なるものであるが、ここで含有せしめられるCr
は、基地を強化し、炭化物を形成して耐磨耗性を
付与し、更に耐酸化性を向上せしめる等、高密
度、高強度部品には必須の元素であり、その有効
な添加効果を得るには７％が下限である。また、
このCrの含有量が30％を越えるようになりと、
粉末冶金操作における成形操作において圧縮性が
著しく低下するようになる。このため、Crの含
有量としては7.0〜30.0％の範囲が採用されるこ
ととなるのである。
また、Mnは、粉末の焼結密度の向上に顕著な
効果を示し、また焼結体の焼入れ性にも好影響を
もたらす元素であつて、このような効果、特に有
効な密度向上効果を発揮させるには、少なくとも
0.1％以上のMnの添加が必須であるが、あまりに
もMnを過度に添加すると粉末の表面酸化を助長
し、更に粉末を球状化させる作用があつて、その
成形性を低下せしめることとなるため、その上限
を1.5％とする必要がある。なお、かかるMnのが
含有量の好ましい範囲としては、一般に0.2〜0.7
％である。
さらに、Ｐは、Ｃの共存により燐化鉄共晶を生
成させるのに必須の成分であつて、そのような燐
化鉄共晶の液相を利用して焼結密度を向上させる
効果を期待するには、少なくとも0.1％含有せし
める必要があるのである。一方、Ｐの過度の添加
は、粉末の圧縮性を低下させ、多量の液相の出現
による焼結温度コントロールを困難にするところ
から、その上限は1.0％である。なお、かかるＰ
の好ましい含有量範囲としては、0.2〜0.7％であ
る。
そして、本発明にあつては、かかる合金粉末に
は、その製造工程中において必然的にＣやSiが含
有せしめられるようになるのであるが、このＣと
しては、その含有量があまりにも多くなり過ぎる
と基地が効果して粉末が硬くなり、その圧縮性を
著しく損ね、以て目的とする成形品を得るのが困
難となつて粉末冶金用としては適さなくなるた
め、一般に0.1％をその上限とすることが望まし
い。また、SIは、粉末製造時の粉末表面酸化を抑
制するのに有効であり、このためその含有量が
0.1％以上となるようにされるが、その過度の含
有は、また粉末の圧縮性を損ねることになるた
め、その上限は4.0％に止められる。
また、本発明において、かかる合金粉末には、
更に5.0％以下のMo（モリブデン）、5.0％以下の
Ｗ（タングステン）、3.0％以下のＶ（バナジウム）、
及び5.0％以下のNb（ニオブ）のうちの１種若し
くは２種以上が含有せしめられている。これら
Mo、Ｗ、Ｖ、Nbは、焼結体中における炭化物の
形成に有効であり、この目的のために添加される
のであるが、その合計の添加総量が10％を越える
ようになると、その添加量に見合つた効果が期待
され得ず、むしろコスト高を惹起するのみである
ところから、その合計量は10％以下とすることが
適当である。
その他、本発明に用いられる粉末冶金用合金粉
末には、上記合金成分の他、必要に応じて更にＳ
やNi、Ｂ、Cu等の高知の添加成分が含有せしめ
られることとなる。なお、Ｓの添加は、粉末を微
粉化して焼結密度を向上させるのに寄与し、また
適量のNi、Ｂ等は焼入れ性を向上せしめる利点
がある。
また、このような添加されるべき各成分は、前
記粉末冶金用合金成分と共に溶融せしめられて、
所定の合金溶湯が調製され、次いでこの合金溶湯
が高知の水噴霧やガス噴霧による噴霧法等の公知
の手法によつて所定の粉末とされるのである。な
お、この公知の粉末化手法にて形成される本発明
に従う粉末冶金用合金粉末は、通常の粉末冶金用
金属粉と同様に適宜の大きさの粒子であり、そし
て適宜の粒度分布を有するものであるが、一般に
500μ（JIS32メツシユ）程度以下、好ましくは
150μ程度以下の粒径の粒子が用いられることと
なる。
そして、本発明に従つて、かくして得られた粉
末冶金用合金粉末を用いて所定の焼結体（焼結部
品）を得るには、従来から知られている各種の粉
末冶金手法が採用されるものであるが、その際、
かかる合金粉末には、0.5〜5.0％、好ましくは１
〜４％の割合（合金粉末重量に対するもの）の炭
素粉末が添加、配合せしめられる。この添加配合
される黒鉛粉末、カーボンブラツク等の炭素粉末
は、焼結時において燐化鉄共晶を生成せしめ、得
られる焼結体の密度を向上させるのに必須の成分
であつて、また焼結体中に炭化物を生成せしめる
ことによつてその耐摩耗性を著しく向上せしめる
効果を奏する。なお、合金粉末に対する炭素粉末
の配合量が0.5％未満では、目的とする共晶の生
成量が少なく、従つて所望の性能が得られず、ま
た５％を越える炭素粉末の添加は、共晶の粗大化
を招き、このため衝撃値を低下せしめる問題を生
じる。それ故、本発明に伴う合金成分に対する炭
素粉末の添加量としては0.5〜５％の範囲の値が
採用されるのである。
そして、かかる合金粉末と炭素粉末との混合物
は、常法に従つて所望の形状に成形、特に加圧成
形（圧縮成形）せしめられて所望の成形品（圧粉
体）が形成され、次いでこれが高温度に加熱され
ることによつて焼結せしめられ、目的とする高密
度、高強度の焼結体（焼結部品）が得られるので
ある。
（発明の効果）
このように、本発明に従えば、Fe−Cr系合金
粉末に更に少なくともMn及びＰの所定量を含有
せしめた粉末冶金用合金粉末を用い、これに所定
割合の炭素粉末を添加、配合して、焼結せしめる
ことによつて、最終製品たる焼結体の密度並びに
強度を著しく向上せしめ得るのであり、これによ
つて焼結部品の適用分野の更なる拡大が図り得る
こととなつたのである。
（実施例）
以下、本発明を更に具体的に明らかにするため
に、本発明に従う幾つかの実施例について説明す
るが、本発明が、かかる実施例の記載によつて何
等の制約をも受けるものではないことは言うまで
もないところである。なお、先に説明した各合金
成分の百分率並びに以下の実施例における百分率
は、何れも特に断わりのない限り、重量基準で示
されるものである。
実施例 １
各種の化学組成を有する合金溶湯から、公知の
水噴霧による粉末化手法によつて、第１表に示さ
れる如き種々なる合金粉末を製造し、次いでこれ
を篩分けして−100メツシユの分級物を取り出し
た後、その分級物重量に対して３％の割合の黒鉛
粉末を添加せしめ、均一に配合せしめた。次い
で、その配合物を5ton／cm2の圧力で加圧成形せし
め、５mm×３mm×30mmの寸法の成形品（圧粉体）
を得て、これを1130℃×30分の真空焼結を施すこ
とによつて、焼結ステンレス鋼の各種の試験片を
製造した。
かくして得られた各種の試験片について、それ
ぞれの焼結密度を水浸法（JIS−Ｚ−2505）で測
定した後、支点間距離20mmの３点曲げ試験を実施
し、それらの結果をまとめて第１表に示した。
かかる第１表の結果から明らかなように、供試
材No.１のものでは、粉末中のMn含有量が少ない
ために、得られた焼結体の焼結密度を低く、抗折
力が低い。また、Mnを多量に含有せしめた供試
材No.５のものでは、粉末の成形時にクラツクが発
生してしまつたために、最後まで試験を綴ること
が出来なかつた。
更に、供試材No.６のものでは、Ｐの含有量が少
ないため焼結密度が低く、抗折力も著しく低い値
となつており、一方Ｐを過剰に添加したNo.９では
共晶組織が粗大化したために、密度が上昇してい
るにも拘わらず、逆に抗折力が低下しているのが
認められた。
これに対して、本発明に従つて得られる供試材
No.２〜４及び７、８のものにあつては、焼結密度
が高く、また抗折力も著しく優れているのであ
る。
なお、供試材No.７及び９の焼結体のミクロ組織
を明らかにするために、それぞれの顕微鏡写真
（400倍）をそれぞれ第１図及び第２図に示すが、
それらの写真の比較からも明らかなように、本発
明により得られるNo.７の供試材は、No.９のものよ
りも遥かに組織が細かく、それ故密度と共に、抗
折力も向上されていることが理解されるのであ
る。
(Technical Field) The present invention relates to a method for manufacturing a high-density, high-strength sintered body, and in particular, a method for manufacturing a sintered body using an alloy powder for powder metallurgy that can provide a high-density, high-strength sintered body. It is related to. (Background technology) Molding from metal powder using powder metallurgy method,
Regarding sintered parts (sintered bodies) obtained by sintering,
In recent years, there has been a remarkable expansion in the field of application, and in particular, there has been a remarkable advance into the field of high-strength parts due to the development of high-density sintering technology using a liquid phase. Conventionally, in powder metallurgy using Cr-based stainless steel powder aimed at developing such high-strength parts, iron phosphide eutectic (Fe-Fe 3 C-Fe 3 P) is produced by simultaneous addition of C and P. The liquid phase is used to improve the sintered density, and the high hardness of the eutectic portion significantly improves the wear resistance. By using this method, it is possible to manufacture sintered bodies with a density ratio of approximately 93%, making it possible to manufacture sintered bodies with a density ratio of approximately 93%. Applications are being made to sliding members, meat machine parts (cutters), etc. However, in order to further expand the field of application of sintered parts obtained by powder metallurgy, it is necessary to further improve their performance. Therefore, it is desired to develop a method for manufacturing such sintered parts. By the way, as is well known, the strength of sintered parts is mainly influenced by (a) the strength of the base, and (b) the density ratio. The strength of the body will be improved. (Problem to be Solved) Here, an object of the present invention is to provide a manufacturing method that can improve the density of the obtained sintered body and, by extension, its strength, and for this purpose, In addition to the conventional addition of C and P, Mn is also added as an essential element to the alloy powder for powder metallurgy used to produce such a sintered body, and this is achieved by the present invention. As a result of repeated detailed experiments by
This is based on the knowledge that the addition of Mn clearly improves the density of the sintered body when manufactured in the same process with the same manufacturing conditions such as molding pressure and sintering temperature. be. (Solution Means) That is, the present invention provides Cr (chromium): 7.0 to 30.0.
%, Mn (manganese): 0.1~1.5%, P (phosphorus): 0.1~
Using an alloy powder for powder metallurgy consisting of 1.0%, balance: Fe (iron) and inevitable impurities, 0.5%
The gist is to add and blend carbon powder in a proportion of ~5.0% and sinter it. In addition, in the present invention, Cr: 7.0 to 30.0%,
Mn: 0.1-1.5%, P: 0.1-1.0%, C (carbon): 0.1
% or less, Si (silicon): 0.1 to 4.0%, balance: Fu and unavoidable impurities. Another feature is that it can be sintered. Furthermore, the present invention provides Cr: 7.0 to 30.0% and Mn:
0.1-1.5%, P: 0.1-1.0%, Mo less than 5.0%
(Molybdenum), 5.0% or less W (Tungsten),
V (vanadium) below 3.0% and Nb below 5.0%
The total content of one or more elements selected from (niobium) is 10% or less, and the remainder:
It is characterized by using an alloy powder for powder metallurgy consisting of Fe and unavoidable impurities, adding and blending carbon powder at a ratio of 0.5 to 5.0%, and sintering it. Furthermore, the present invention includes Cr: 7.0 to 30.0%,
Mn: 0.1-1.5%, P: 0.1-1.0%, C: 0.1%
Below, Si: 0.1~4.0%, Mo below 5.0%, 5.0
% or less W, 3.0% or less V, and 5.0% or less Nb, with a total content of 10% or less of one or more elements selected from 10% or less, and the balance: Fe and unavoidable impurities. It is also characterized by using an alloy powder for powder metallurgy, adding and blending carbon powder in a proportion of 0.5 to 5.0%, and sintering it. (Specific configuration) By the way, the alloy powder for powder metallurgy used in the present invention contains 7.0 to 30.0% Cr and 0.1 to 30.0% Cr.
It contains 1.5% Mn and 0.1 to 1.0% P as main alloy components, and the remainder consists of Fe and inevitable impurities, but the Cr contained here
is an essential element for high-density, high-strength parts, as it strengthens the base, forms carbides, imparts wear resistance, and further improves oxidation resistance, and obtains its effective additive effect. The lower limit is 7%. Also,
When the Cr content exceeds 30%,
Compressibility becomes significantly reduced during forming operations in powder metallurgy operations. Therefore, a range of 7.0 to 30.0% is adopted as the Cr content. In addition, Mn is an element that has a remarkable effect on improving the sintered density of powder and also has a positive effect on the hardenability of sintered bodies, and exhibits such effects, especially effective density-improving effects. To let at least
It is essential to add 0.1% or more of Mn, but adding too much Mn will promote surface oxidation of the powder, and will also have the effect of making the powder spheroidal, reducing its formability. , the upper limit should be set at 1.5%. The preferred range of Mn content is generally 0.2 to 0.7.
%. Furthermore, P is an essential component to generate iron phosphide eutectic due to the coexistence of C, and it is expected that the liquid phase of such iron phosphide eutectic will be used to improve the sintered density. To achieve this, it is necessary to contain at least 0.1%. On the other hand, excessive addition of P reduces the compressibility of the powder and makes it difficult to control the sintering temperature due to the appearance of a large amount of liquid phase, so the upper limit is 1.0%. In addition, such P
The preferred content range is 0.2 to 0.7%. In the present invention, the alloy powder inevitably contains C and Si during its manufacturing process, but the content of C is too large. If it is too high, the powder will become hard due to the matrix effect, significantly impairing its compressibility, making it difficult to obtain the desired molded product, and making it unsuitable for powder metallurgy. Therefore, the upper limit is generally set at 0.1%. It is desirable to do so. In addition, SI is effective in suppressing powder surface oxidation during powder manufacturing, and therefore its content is
The content is set at 0.1% or more, but excessive content also impairs the compressibility of the powder, so the upper limit is limited to 4.0%. In addition, in the present invention, such alloy powder includes:
Furthermore, Mo (molybdenum) of 5.0% or less, W (tungsten) of 5.0% or less, V (vanadium) of 3.0% or less,
and 5.0% or less of Nb (niobium). these
Mo, W, V, and Nb are effective in forming carbides in the sintered body and are added for this purpose, but if the total amount of addition exceeds 10%, Since no effect commensurate with the amount can be expected, and rather only increases costs, it is appropriate that the total amount is 10% or less. In addition to the above-mentioned alloy components, the alloy powder for powder metallurgy used in the present invention further includes S as needed.
Kochi's additive components such as Ni, B, and Cu are included. Note that the addition of S contributes to pulverizing the powder and improving the sintered density, and the addition of appropriate amounts of Ni, B, etc. has the advantage of improving hardenability. Further, each of the components to be added is melted together with the powder metallurgy alloy component,
A predetermined molten alloy is prepared, and then this molten alloy is made into a predetermined powder by a known method such as Kochi's atomization method using water spray or gas atomization. In addition, the alloy powder for powder metallurgy according to the present invention formed by this known powdering method has particles of an appropriate size and an appropriate particle size distribution like ordinary metal powder for powder metallurgy. However, in general
500μ (JIS32 mesh) or less, preferably
Particles with a particle size of about 150μ or less will be used. According to the present invention, various conventionally known powder metallurgy methods are employed to obtain a predetermined sintered body (sintered part) using the powder metallurgy alloy powder thus obtained. However, in that case,
Such alloy powders contain 0.5-5.0%, preferably 1
Carbon powder in a proportion of ~4% (relative to the weight of the alloy powder) is added and incorporated. This added carbon powder such as graphite powder and carbon black is an essential component for generating iron phosphide eutectic during sintering and improving the density of the obtained sintered body. By producing carbide in the compact, it has the effect of significantly improving its wear resistance. Note that if the amount of carbon powder added to the alloy powder is less than 0.5%, the amount of the desired eutectic produced will be small and the desired performance will not be obtained. This causes the problem of coarsening of the particles, which reduces the impact value. Therefore, the amount of carbon powder added to the alloy components according to the present invention is in the range of 0.5 to 5%. The mixture of such alloy powder and carbon powder is then molded into a desired shape according to a conventional method, particularly pressure molded (compression molding) to form a desired molded product (green compact), which is then molded into a desired shape. It is sintered by being heated to a high temperature, and the desired high-density, high-strength sintered body (sintered part) is obtained. (Effects of the Invention) According to the present invention, an alloy powder for powder metallurgy in which Fe-Cr alloy powder further contains at least a predetermined amount of Mn and P is used, and a predetermined proportion of carbon powder is added to the powder metallurgy alloy powder. By adding, blending, and sintering, it is possible to significantly improve the density and strength of the final product, sintered body, thereby further expanding the fields of application of sintered parts. It became. (Examples) In order to clarify the present invention more specifically, some examples according to the present invention will be described below, but the present invention is not limited in any way by the description of such examples. Needless to say, it is not a thing. Note that the percentages of each alloy component described above and the percentages in the following examples are all expressed on a weight basis unless otherwise specified. Example 1 Various alloy powders as shown in Table 1 were produced from molten alloys having various chemical compositions by a known powdering method using water spray, and then sieved to -100 mesh. After taking out the fractionated material, graphite powder was added at a ratio of 3% based on the weight of the fractionated material, and the mixture was uniformly blended. Next, the mixture was press-molded at a pressure of 5 ton/cm 2 to form a molded product (green compact) with dimensions of 5 mm x 3 mm x 30 mm.
This was vacuum sintered at 1130°C for 30 minutes to produce various test pieces of sintered stainless steel. After measuring the sintered density of each of the various test pieces obtained in this way using the water immersion method (JIS-Z-2505), a three-point bending test was conducted with a distance between supports of 20 mm, and the results were summarized. It is shown in Table 1. As is clear from the results in Table 1, sample material No. 1 has a low Mn content in the powder, so the sintered density of the obtained sintered body is low, and the transverse rupture strength is low. low. In addition, with sample material No. 5 containing a large amount of Mn, cracks occurred during molding of the powder, so the test could not be completed to the end. Furthermore, sample material No. 6 has a low sintered density and a significantly low transverse rupture strength due to the low content of P, while sample material No. 9, in which P is added in excess, has a eutectic structure. It was observed that the transverse rupture strength decreased, even though the density increased due to the coarsening of the fibers. In contrast, the test material obtained according to the present invention
In the case of Nos. 2 to 4, 7, and 8, the sintered density is high and the transverse rupture strength is also extremely excellent. In order to clarify the microstructures of the sintered bodies of test materials No. 7 and 9, micrographs (400x magnification) are shown in Figures 1 and 2, respectively.
As is clear from the comparison of those photographs, specimen No. 7 obtained by the present invention has a much finer structure than specimen No. 9, and therefore has improved transverse rupture strength as well as density. It is understood that there is.
【表】【table】
【表】
実施例 ２
Ｃの含有量が0.05％以下に調製された種々なる
化学組成を有する各種の合金溶湯から、実施例１
と同様にして水噴霧による粉末化手法にて各種の
合金粉末を製造した。各粉末の化学組成は略第２
表に示される通りである（但し、Ｃは除く）。
そして、その得られた粉末のそれぞれを篩分け
して−100メツシユのものを集めた。次いで、こ
の−100メツシユの分級物に対して、第２表に示
される如き各種のＣ値を与える割合で炭素粉末を
それぞれ添加せしめ、均一に混合せしめた後、実
施例１と同様にして成形、焼結して各種の試験片
を製造した。焼結後の各供試材の化学組成を第２
表に示す。
得られた各試験片の評価結果を、下記第２表に
示すが、合金粉末に対するＣの添加量の少ない供
試材No.10では、焼結密度が上がらず、抗折力が低
い。一方、Ｃを多量に添加した供試材No.14では、
共晶組織が粗大化しているために、密度が向上さ
れているにも拘わらず、抗折力は低下しているの
である。
これに対して、本発明にて得られる供試材No.11
〜13のものは、何れも焼結密度、抗折力とも著し
く改善されているのが理解される。[Table] Example 2 Example 1 was prepared from various molten alloys with various chemical compositions prepared to have a C content of 0.05% or less.
Various alloy powders were produced using a powdering method using water spray in the same manner as described above. The chemical composition of each powder is approximately the second
As shown in the table (however, C is excluded). Then, each of the obtained powders was sieved to collect -100 mesh. Next, to this -100 mesh classified material, carbon powder was added in proportions giving various C values as shown in Table 2, mixed uniformly, and then molded in the same manner as in Example 1. , and sintered to produce various test pieces. The chemical composition of each sample material after sintering was
Shown in the table. The evaluation results of each test piece obtained are shown in Table 2 below. Sample material No. 10, in which the amount of C added to the alloy powder was small, did not increase the sintered density and had a low transverse rupture strength. On the other hand, in sample material No. 14 with a large amount of C added,
Because the eutectic structure has become coarser, the transverse rupture strength is lower despite the improved density. On the other hand, sample material No. 11 obtained by the present invention
It is understood that all of samples 1 to 13 have significantly improved sintered density and transverse rupture strength.
【表】
実施例 ３
下記第３表に示される化学組成を有する合金溶
湯を用いて、公知の水噴霧による粉末化手法によ
て、種々なる合金粉末を製造した後、実施例１と
同様にして分級し、更にその分級物に対して炭素
粉末を２％添加して均一にブレンドせしめ、更に
その後実施例１と同様にして試験片を製造し、特
性を調査した。
その結果を第４表に示すが、かかる第４表から
明らかなように、本発明に従つて得られる焼結体
No.16〜21は、その焼結密度が著しく向上せしめら
れており、またその抗折力も著しく向上されてい
る。一方、Mo、Ｗ、Ｖ、Nbを過剰に添加したNo.
22、23のものでは成形が不可能であつた。
なお、かかる効果は、水噴霧による粉末化手法
に代えて、他の手法であるガス噴霧による粉末化
手法によつて得られた合金粉末であつても同様に
達成されることが確認された。[Table] Example 3 Using a molten alloy having the chemical composition shown in Table 3 below, various alloy powders were produced by a known powdering method using water spray, and then processed in the same manner as in Example 1. Further, 2% of carbon powder was added to the classified product and blended uniformly. Thereafter, test pieces were manufactured in the same manner as in Example 1, and their properties were investigated. The results are shown in Table 4, and as is clear from Table 4, the sintered body obtained according to the present invention
Nos. 16 to 21 have significantly improved sintered densities and also have significantly improved transverse rupture strengths. On the other hand, No. with excessive addition of Mo, W, V, and Nb.
Nos. 22 and 23 were impossible to mold. It has been confirmed that this effect can be similarly achieved even when the alloy powder is obtained by another method, that is, a powdering method using gas spraying, instead of the powdering method using water spraying.
【表】【table】
【表】【table】
第１図及び第２図は、それぞれ実施例１におい
て本発明に従つて得られた焼結体と比較例の焼結
体の金属組織を示す顕微鏡写真である。
FIGS. 1 and 2 are micrographs showing the metal structures of the sintered body obtained according to the present invention in Example 1 and the sintered body of Comparative Example, respectively.
Claims (1)
〜1.0％、残部：Fe及び不可避的不純物からなる
粉末冶金用合金粉末を用い、これに対して0.5〜
5.0％の割合の炭素粉末を添加、配合して、焼結
せしめることを特徴とする高密度高強度焼結体の
製造法。 ２ Cr：7.0〜30.0％、Mn：0.1〜1.5％、Ｐ：0.1
〜1.0％、Ｃ：0.1％以下、Si：0.1〜4.0％、残部：
Fe及び不可避的不純物からなる粉末冶金用合金
粉末を用い、これに対して0.5〜5.0％の割合の炭
素粉末を添加、配合して、焼結せしめることを特
徴とする高密度高強度焼結体の製造法。 ３ Cr：7.0〜30.0％と、Mn：0.1〜1.5％と、
Ｐ：0.1〜1.0％と、5.0％以下のMo、5.0％以下の
Ｗ、3.0％以下のＶ及び5.0％以下のNbのうちから
選ばれた１種若しくは２種以上の元素の合計と含
有量で10％以下と、残部：Fe及び不可避的不純
物とからなる粉末冶金用合金粉末を用い、これに
対して0.5〜5.0％の割合の炭素粉末を添加、配合
して、焼結せしめることを特徴とする高密度高強
度焼結体の製造法。 ４ Cr：7.0〜30.0％と、Mn：0.1〜1.5％と、
Ｐ：0.1〜1.0％と、Ｃ：0.1％以下と、Si：0.1〜
4.0％と、5.0％以下のMo、5.0％以下のＷ、3.0％
以下のＶ及び5.0％以下のNbのうちから選ばれた
１種若しくは２種以上の元素の合計の含有量で10
％以下と、残部：Fe及び不可避的不純物とから
なる粉末冶金用合金粉末を用い、これに対して
0.5〜5.0％の割合の炭素粉末を添加、配合して、
焼結せしめることを特徴とする高密度高強度焼結
体の製造法。[Claims] 1 Cr: 7.0-30.0%, Mn: 0.1-1.5%, P: 0.1
~1.0%, balance: 0.5 ~ using powder metallurgy alloy powder consisting of Fe and unavoidable impurities
A method for producing a high-density, high-strength sintered body, characterized by adding and blending carbon powder at a ratio of 5.0% and sintering it. 2 Cr: 7.0-30.0%, Mn: 0.1-1.5%, P: 0.1
~1.0%, C: 0.1% or less, Si: 0.1-4.0%, remainder:
A high-density, high-strength sintered body characterized by using an alloy powder for powder metallurgy consisting of Fe and inevitable impurities, adding and blending carbon powder at a ratio of 0.5 to 5.0%, and sintering the mixture. manufacturing method. 3 Cr: 7.0 to 30.0%, Mn: 0.1 to 1.5%,
P: 0.1 to 1.0% and the total and content of one or more elements selected from 5.0% or less Mo, 5.0% or less W, 3.0% or less V, and 5.0% or less Nb. It is characterized by using an alloy powder for powder metallurgy consisting of 10% or less and the balance being Fe and unavoidable impurities, adding and blending carbon powder at a ratio of 0.5 to 5.0%, and sintering it. A method for manufacturing high-density, high-strength sintered bodies. 4 Cr: 7.0 to 30.0%, Mn: 0.1 to 1.5%,
P: 0.1~1.0%, C: 0.1% or less, Si: 0.1~
4.0%, Mo less than 5.0%, W less than 5.0%, 3.0%
The total content of one or more elements selected from the following V and 5.0% or less Nb is 10
% or less, and the balance: Fe and unavoidable impurities.
By adding and blending carbon powder at a ratio of 0.5 to 5.0%,
A method for producing a high-density, high-strength sintered body characterized by sintering.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7229189A JPH01283340A (en) | 1989-03-25 | 1989-03-25 | Manufacturing method for high-density, high-strength sintered bodies |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7229189A JPH01283340A (en) | 1989-03-25 | 1989-03-25 | Manufacturing method for high-density, high-strength sintered bodies |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12735182A Division JPS5920401A (en) | 1982-07-21 | 1982-07-21 | Alloy powder for powder metallurgy and its sintered body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01283340A JPH01283340A (en) | 1989-11-14 |
| JPH0375621B2 true JPH0375621B2 (en) | 1991-12-02 |
Family
ID=13485022
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7229189A Granted JPH01283340A (en) | 1989-03-25 | 1989-03-25 | Manufacturing method for high-density, high-strength sintered bodies |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01283340A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3489617B2 (en) * | 1999-08-10 | 2004-01-26 | 株式会社栗本鐵工所 | Wear-resistant alloy cast iron |
| JP4849770B2 (en) * | 2003-02-13 | 2012-01-11 | 三菱製鋼株式会社 | Alloy steel powder for metal injection molding with improved sinterability |
| JP4912188B2 (en) * | 2006-03-14 | 2012-04-11 | 株式会社神戸製鋼所 | Mixed powder for powder metallurgy, its green compact, and sintered body |
| JP5344975B2 (en) * | 2009-04-13 | 2013-11-20 | 富士フイルム株式会社 | Recording tape cartridge |
-
1989
- 1989-03-25 JP JP7229189A patent/JPH01283340A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01283340A (en) | 1989-11-14 |
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