JPH0533299B2 - - Google Patents
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- Publication number
- JPH0533299B2 JPH0533299B2 JP62238504A JP23850487A JPH0533299B2 JP H0533299 B2 JPH0533299 B2 JP H0533299B2 JP 62238504 A JP62238504 A JP 62238504A JP 23850487 A JP23850487 A JP 23850487A JP H0533299 B2 JPH0533299 B2 JP H0533299B2
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- Prior art keywords
- powder
- alloy
- less
- wear resistance
- producing
- Prior art date
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- 239000000843 powder Substances 0.000 claims description 56
- 229910045601 alloy Inorganic materials 0.000 claims description 43
- 239000000956 alloy Substances 0.000 claims description 43
- 238000004519 manufacturing process Methods 0.000 claims description 22
- 239000002245 particle Substances 0.000 claims description 18
- 229910000851 Alloy steel Inorganic materials 0.000 claims description 17
- 229910052742 iron Inorganic materials 0.000 claims description 15
- 238000005245 sintering Methods 0.000 claims description 14
- 239000012535 impurity Substances 0.000 claims description 10
- 238000002844 melting Methods 0.000 claims description 10
- 230000008018 melting Effects 0.000 claims description 10
- 239000011812 mixed powder Substances 0.000 claims description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 8
- 229910052802 copper Inorganic materials 0.000 claims description 8
- 239000007791 liquid phase Substances 0.000 claims description 8
- 229910052799 carbon Inorganic materials 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- 238000000034 method Methods 0.000 claims description 7
- 229910052750 molybdenum Inorganic materials 0.000 claims description 6
- 230000001050 lubricating effect Effects 0.000 claims description 5
- 229910052721 tungsten Inorganic materials 0.000 claims description 5
- 229910052720 vanadium Inorganic materials 0.000 claims description 5
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- 229910052758 niobium Inorganic materials 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 17
- 230000000694 effects Effects 0.000 description 16
- 239000010949 copper Substances 0.000 description 10
- 150000001247 metal acetylides Chemical class 0.000 description 9
- 230000007423 decrease Effects 0.000 description 7
- 239000011159 matrix material Substances 0.000 description 7
- 239000011133 lead Substances 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 229910052804 chromium Inorganic materials 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 230000013011 mating Effects 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910000599 Cr alloy Inorganic materials 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 229910000531 Co alloy Inorganic materials 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- CADICXFYUNYKGD-UHFFFAOYSA-N sulfanylidenemanganese Chemical compound [Mn]=S CADICXFYUNYKGD-UHFFFAOYSA-N 0.000 description 1
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
Description
〔産業上の利用分野〕
本発明は、高温耐摩耗性に優れた焼結合金の製
造方法に関するものである。
〔従来の技術〕
自動車等の内燃機関に用いられる動弁部材は、
Fe、Mo、Co、Ｃ等を含む鉄系金属粉末から形成
した焼結合金が用いられることが多いが、最近の
自動車等の内燃機関の高性能化に伴い、高温耐摩
耗性や高温強度を尚一層上昇させる必要性が大き
くなつている。
そのため、近時本発明者らは高温耐摩耗性及び
高温強度をより一層高めた焼結合金を製造する方
法を開発した。すなわち、「高温耐摩耗性に優れ
た（含銅）焼結合金の製造方法」（特願昭59−
73240号、同昭59−74396号、同昭60−13786号明
細書等）において、合金鋼粉末を主体とする成形
体を、液相を生ぜしめつつ焼結することにより、
成形体中の残留気孔をできるだけ少なくし、高温
強度を高めた焼結合金の製造方法について提案し
た。本発明者らは上記特許願において更に、潤滑
成分として銅あるいは銅合金、鉛、硫化マンガン
等を溶浸あるいは混合粉末に添加することによ
り、又、コバルト系合金粉末を添加して基地と炭
化物の結合力を強めることにより、高温での耐摩
耗性を高める方法を提示している。
〔発明が解決しようとする問題点〕
しかしながら、最近のバルブシートに対する耐
摩耗性の要求には更に厳しいものがあり、従来の
合金鋼粉末が含有する成分から焼結時に生成され
る炭化物のみでは、耐摩耗性硬質粒子としての性
状例えば硬さ、粒子径等が不十分である。
本発明は上記従来技術における問題点を解決す
るためのものであり、その目的とするところは従
来よりも更に優れた高温耐摩耗性を有する焼結合
金を容易に得ることができる製造方法を提供する
ことにある。
〔問題点を解決するための手段〕
すなわち本発明の高温耐摩耗性に優れた焼結合
金の製造方法は、
(a) 重量比で、Cr20〜80％、W5〜30％、Mo2〜
20％、Fe30％以下、C0.5〜７％、不可避不純
物１％以下及び残部Coからなる、基地中に拡
散・埋設されて硬質粒子となるCr系合金粉末
と、
重量比で、少なくともCr2.5〜25％、C0.2〜
3.0％、不可避不純物及び残部Feからなる合金
鋼粉末とCu3P、Fe3P、Fe2Bの一種以上からな
る低融点合金粉末とからなるFe系金属粉末と
を混合し成形体を形成する成形工程と、
(b) 該成形体を加熱して該成形体中に低融点の液
相を部分的に生ぜしめて液相焼結を行いつつ該
成形体の本焼結を行い、気孔率５％以下の焼結
合金を形成する焼結工程からなることを特徴と
する。
本発明の製造方法の好ましい態様としては以下
の方法が挙げられる。
(i) Cr系合金粉末が重量比で５〜25％であるこ
とを特徴とする製造方法。
(ii) 低融点合金粉末の代わりに、低融点合金粉末
とPb、MnSの一種以上からなる潤滑性粉末と
を混合した混合粉末を使用することを特徴とす
る製造方法。
(iii) 混合粉末中、Ｐが0.1〜0.8重量％であること
を特徴とする上記(ii)の製造方法。
(iv) 混合粉末が、Pb0.2〜10重量％、MnS0.1〜３
重量％のうち一種又は二種を含むことを特徴と
する上記(ii)の製造方法。
(v) 合金鋼粉末中の不可避不純物が重量比で0.3
％以下のＯ、1.5％以下のSi、0.5％以下のMn
及びその他の不純物１％以下からなることを特
徴とする上記（）の製造方法。
(vi) 合金鋼粉末が重量比でMo0.3〜6.5％、W0.5
〜12％、V0.25〜5.5％、Nb0.05〜３％のうち
一種又は二種以上を含み、且つMo、Ｗ、Ｖ、
Nbの合計が16％以下であることを特徴とする
上記(ii)の製造方法。
(vii) 合金鋼粉末が重量比でCo2.0〜20％、Ni0.5〜
10％、Cu1〜５％のうち一種又は二種以上を含
み、且つCo、Ni、Cuの合計が20％以下である
ことを特徴とする上記(ii)の製造方法。
(viii) Fe系金属粉末がグラフアイト粉末を含むこ
とを特徴とする製造方法。
本発明は従来使用している合金鋼粉末中に、
Crを主体とする合金粉末を添加して液相焼結を
行うことにより、基地とCr基合金粉末粒子との
間に部分的な相互拡散を生ぜしめてその結合を強
めることにより、強度の極端な低下を防止しつつ
高温における耐摩耗性を向上させるものである。
基地となる合金鋼粉末は元来Crを多量に含有し
ているため高温における強度は優れているが、耐
摩耗性粒子を焼結時に生成する炭化物のみとした
場合には、その粒径が小さすぎるために期待する
耐摩耗性を十分に得られない。一方、所定の耐摩
耗性を得るために一定粒子径の硬質粒子を添加す
ると組織の均一性が損なわれ極端な強度低下を示
す。本発明は添加する硬質粒子の組成を検討し、
強度低下を許容範囲内に抑え且つ耐摩耗性を付与
したものである。
以下に本発明の方法における各成分の範囲又は
各成分の好ましい範囲について述べる。なお％は
重量％を示す。
Cr系合金粉末
(a) CrはＣと化合して炭化物を形成するととも
に一部がMo、Coと合金を形成し、硬質粒子の
硬さを向上させる効果を有するが20％未満では
上記の効果がなく、又80％を越える場合は脆化
して粒子の割れや脱落が発生する。そのため20
〜80％とする。
(b) ＷはＣと化合して硬質炭化物を形成し硬質粒
子の硬さを向上させる効果を有するが、５％未
満ではその効果が発揮されず、30％を越える場
合には硬くなりすぎて相手バルブを攻撃する。
そのため５〜30％とする。
(c) MoはＣと化合して炭化物を形成し、一部が
Cr、Coと合金を形成し硬質粒子の硬さを向上
させる効果があるが、２％未満ではその効果が
なく20％を越える場合には硬くなりすぎて相手
バルブを攻撃する。そのため２〜20％とする。
(d) ＣはCr、Ｗ、Ｖ、Nbと化合して炭化物を形
成して硬質粒子の硬さを向上させるが、0.5％
未満ではその効果がなく、７％を越える場合に
は炭化物が多すぎて脆くなる。そのため0.5〜
７％とする。
(e) Feは高価なCoの代替として添加されコスト
低減効果があるが、30％を越えると耐摩耗性が
低下するため30％以下とする。
(f) 硬質粒子は耐摩耗性向上に効果があるが、５
％未満ではその効果が発揮されず25％を越える
場合には成形性、焼結性及び被削性が低下する
とともに相手攻撃性も増大する。そのため５〜
25％が好ましい。
Fe系金属粉末
(g) CrはMo、Ｗ、Ｖ、Nbとともに炭化物を形
成し耐摩耗性に寄与するが、25％未満では耐摩
耗性が不足するか又は添加効果が少ない。又25
％を越える場合には炭化物の析出が大のため相
手材攻撃性が増加する。又、Nbは結晶粒微細
化にも寄与する。そのためCrは2.5〜25％とす
る。
(h) Ｃはマトリツクスに固容して強度を高め、又
Cr、Mo、Ｗ、Ｖ、Nb等と結合した炭化物を
形成し耐摩耗性向上に寄与する。しかし0.2％
未満では効果が期待できず、3.0％を越えると
逆に炭化物過剰、炭化物粗大化を生じ焼結合金
の強度低下や相手材攻撃性増加等の不具合を生
ずる。そのためＣは0.2〜3.0％とする。
(i) Co及びNiはマトリツクスに固溶して特に高
温強度や靭性を改善し、又耐酸化耐食性を高め
る他、耐摩耗性改善効果も示すが、Coは2.0％、
Niは0.5％未満では効果がない。又Coは20％、
Niは10％を越えると改善効果が頭打ちとなる。
そのためCoは2.0〜20％、Niは0.5〜10％が好ま
しい。
(j) Cuはマトリツクスに固溶してマトリツクス
を強化し硬さを増す他、析出炭化物粒子の微細
均一化に役立つ。又、CuはCuを主体とする溶
融金属を溶浸する際に、ぬれ性の改善や溶浸量
の安定化にも寄与する。その最適範囲は１〜５
％である。
(k) Siは炭化物の球状化や焼結温度低下の効果を
持つが、1.5％を越えると逆に焼結性の低下や
強度低下をきたすので好ましくない。Mnはマ
トリツクスの強化の効果があるが、0.5％を越
えると粉末の硬化の他、粉末の酸化による焼結
性の低下等が問題となることがある。そのため
Siは1.5％以下、Mnは0.5％以下が好ましい。
(l) Ｏは主として粉末の表面にできる酸化物やス
ラグに含まれ、0.5％を越えると焼結性を著し
く阻害するため、0.3％以下が好ましい。
(m) 潤滑性粉末のうち、Pb粉末を用いる場合、
その使用量は0.2％〜10％が好ましい。0.2％未
満では潤滑効果がなく、10％を越えると相対的
に基地強度が低下し、耐摩耗性が低下するため
である。一方、MnSの場合、使用量は0.1〜３
％とする。限定理由はPbの場合と同様である。
尚焼結合金中の炭素は、合金鋼粉末から供給し
た方がよい。その理由は、グラフアイト粉末から
後添加という形態で供給するよりも焼結性が安定
し、気孔分布や炭化物の分布がより均一になり、
更に寸法精度も向上するからである。
但し、特殊な例としては、炭素を含む合金鋼粉
末の他に、グラフアイト粉末等の炭素源を別途追
加し、焼結時の粉末の脱酸や焼結温度の低下等を
図ることにしてもよい。低融点化合物としては、
Cu3P、Fe3P、Fe2Bの一種以上を使用する。
〔実施例〕
以下の実施例において本発明を更に詳細に説明
する。なお、本発明は下記実施例に限定されるも
のではない。
実施例 １
基地合金鋼粉末には、合金鋼粉末全体を100重
量％とした場合に、重量比でCr12％、C1.5％、
Mo1％、V0.8％、Si0.2％、Mn0.3％、O0.04％、
残部Fe及び１％以下の不純物からなる噴霧合金
鋼粉末（−100メツシユ）を用いた。又、Cr系合
金粉末には、Cr系合金粉末全体を100重量％とし
た場合、重量比でCo10％、W15％、Mo10％、
Fe10％、C5.5％、O0.4％、残部Cr及び１％以下
の不純物からなる噴霧合金粉末（−100メツシユ）
を用いた。但し、Cr系合金粉末は、噴霧時に
個々の粉末内部にガスを巻き込み空洞化している
ものもあるため、噴霧後にボールミル等により粉
砕してもよい。そして混合粉末全体で100重量％
となるように、基地合金鋼粉末にCr系合金粉末
10％、Fe3P粉末1.5％（−200メツシユ）、グラフ
アイト粉末1.1％（−350メツシユ）、MnS粉末0.3
％を添加し、更に潤滑剤としてステアリン酸亜鉛
0.8％を加えて混合粉末を形成し、この混合粉末
を7.0ton／cm2で圧縮成形して内径10mm、外径20
mm、長さ20mmの環状圧粉体とした。次いでこれを
アンモニア分解ガス雰囲気において1150℃で30分
間加熱し、液相を生じさせつつ焼結を行い、焼結
合金製の試験片を製造した。
実施例 ２ないし４
成分組成を変えて、実施例１と同様にして試験
片を製造した。
比較例
実施例１に示した試料からCr系合金粉末を除
いた組成とし、実施例１と同様の方法で試験片を
製造した。
下記表１及び表２に、実施例１〜４及び比較例
の基地合金鋼粉末、Cr系合金粉末、その他の添
加成分の組成、配合割合及び製造条件を示す。
[Industrial Application Field] The present invention relates to a method for producing a sintered alloy with excellent high-temperature wear resistance. [Prior Art] Valve train members used in internal combustion engines such as automobiles are
Sintered alloys made from iron-based metal powders containing Fe, Mo, Co, C, etc. are often used, but with the recent improvement in the performance of internal combustion engines such as automobiles, high-temperature wear resistance and high-temperature strength are being improved. There is a growing need to further increase this. Therefore, the present inventors have recently developed a method for producing a sintered alloy with further improved high-temperature wear resistance and high-temperature strength. That is, ``Method for producing (copper-containing) sintered alloy with excellent high-temperature wear resistance'' (patent application 1982-
No. 73240, No. 59-74396, No. 13786 (1983), etc.), by sintering a molded body mainly composed of alloy steel powder while producing a liquid phase,
We proposed a method for manufacturing sintered alloys that minimizes residual pores in compacts and increases high-temperature strength. In the above patent application, the present inventors have further disclosed that by infiltrating or adding copper or copper alloy, lead, manganese sulfide, etc. as a lubricating component to the mixed powder, and by adding cobalt-based alloy powder, the matrix and carbide can be separated. We present a method to increase wear resistance at high temperatures by strengthening bonding strength. [Problems to be Solved by the Invention] However, recent demands for wear resistance on valve seats are even more stringent, and carbides produced during sintering from components contained in conventional alloy steel powder alone cannot be used alone. The properties of wear-resistant hard particles, such as hardness and particle size, are insufficient. The present invention is intended to solve the above-mentioned problems in the prior art, and its purpose is to provide a manufacturing method that can easily produce a sintered alloy that has even better high-temperature wear resistance than the prior art. It's about doing. [Means for solving the problem] That is, the method for producing a sintered alloy with excellent high-temperature wear resistance according to the present invention is as follows: (a) By weight, Cr20-80%, W5-30%, Mo2-
20% Fe, 30% or less C, 0.5-7% C, 1% or less unavoidable impurities, and the balance Co, which is diffused and buried in the base to become hard particles.The weight ratio is at least Cr2. 5~25%, C0.2~
A compact is formed by mixing an alloy steel powder consisting of 3.0% Fe, unavoidable impurities, and the balance Fe-based metal powder consisting of a low melting point alloy powder consisting of one or more of Cu 3 P, Fe 3 P, and Fe 2 B. (b) main sintering of the compact while performing liquid phase sintering by heating the compact to partially generate a low melting point liquid phase in the compact, and % or less of sintered alloy. Preferred embodiments of the production method of the present invention include the following method. (i) A manufacturing method characterized in that Cr-based alloy powder accounts for 5 to 25% by weight. (ii) A manufacturing method characterized by using a mixed powder of a low melting point alloy powder and a lubricating powder made of one or more of Pb and MnS instead of the low melting point alloy powder. (iii) The manufacturing method according to (ii) above, wherein P is 0.1 to 0.8% by weight in the mixed powder. (iv) The mixed powder contains 0.2 to 10% by weight of Pb and 0.1 to 3% by weight of MnS.
The manufacturing method according to (ii) above, characterized in that it contains one or two of the above by weight%. (v) Unavoidable impurities in alloy steel powder are 0.3 by weight
% or less O, 1.5% or less Si, 0.5% or less Mn
and 1% or less of other impurities. (vi) Alloy steel powder has a weight ratio of Mo0.3 to 6.5% and W0.5
~12%, V0.25~5.5%, Nb0.05~3%, and contains one or more of Mo, W, V,
The manufacturing method according to (ii) above, characterized in that the total amount of Nb is 16% or less. (vii) Alloy steel powder has a weight ratio of Co2.0~20% and Ni0.5~
10%, Cu, 1 to 5%, and the total content of Co, Ni, and Cu is 20% or less. (viii) A manufacturing method characterized in that the Fe-based metal powder contains graphite powder. In the present invention, in the conventionally used alloy steel powder,
By performing liquid phase sintering with the addition of Cr-based alloy powder, partial interdiffusion is created between the base and Cr-based alloy powder particles to strengthen the bond, resulting in extreme strength. This improves wear resistance at high temperatures while preventing deterioration.
The base alloy steel powder originally contains a large amount of Cr, so it has excellent strength at high temperatures, but if the only wear-resistant particles are carbides produced during sintering, the particle size is small. Because of this, it is not possible to obtain the desired wear resistance. On the other hand, when hard particles of a certain particle size are added to obtain a predetermined wear resistance, the uniformity of the structure is impaired, resulting in an extreme decrease in strength. The present invention considers the composition of hard particles to be added,
This suppresses the decrease in strength within an acceptable range and provides wear resistance. The range of each component or the preferred range of each component in the method of the present invention will be described below. Note that % indicates weight %. Cr-based alloy powder (a) Cr combines with C to form carbide, and a portion also forms an alloy with Mo and Co, which has the effect of improving the hardness of hard particles, but if it is less than 20%, the above effect will not occur. If it is absent or exceeds 80%, it will become brittle and particles will crack or fall off. Therefore 20
~80%. (b) W combines with C to form hard carbides and has the effect of improving the hardness of hard particles, but if it is less than 5%, this effect is not exhibited, and if it exceeds 30%, it becomes too hard. Attack the opponent's valve.
Therefore, it is set at 5 to 30%. (c) Mo combines with C to form carbide, and some
It forms an alloy with Cr and Co and has the effect of improving the hardness of hard particles, but if it is less than 2% it has no effect and if it exceeds 20% it becomes too hard and attacks the mating valve. Therefore, it is set at 2 to 20%. (d) C combines with Cr, W, V, and Nb to form carbides and improves the hardness of hard particles, but at 0.5%
If it is less than 7%, there is no effect, and if it exceeds 7%, there will be too much carbide and it will become brittle. Therefore 0.5~
7%. (e) Fe is added as a substitute for expensive Co and has a cost reduction effect, but if it exceeds 30%, wear resistance decreases, so it should be kept at 30% or less. (f) Hard particles are effective in improving wear resistance, but 5
If it is less than 25%, the effect will not be exhibited, and if it exceeds 25%, the formability, sinterability and machinability will decrease, and the aggressiveness against others will increase. Therefore 5～
25% is preferred. Fe-based metal powder (g) Cr forms carbides together with Mo, W, V, and Nb and contributes to wear resistance, but if it is less than 25%, the wear resistance is insufficient or the effect of addition is small. Also 25
If it exceeds %, carbide precipitation is large and the attack on the mating material increases. Furthermore, Nb also contributes to grain refinement. Therefore, Cr is set at 2.5 to 25%. (h) C is solidified in a matrix to increase strength, and
It forms carbides combined with Cr, Mo, W, V, Nb, etc. and contributes to improving wear resistance. But 0.2%
If it is less than 3.0%, no effect can be expected, and if it exceeds 3.0%, conversely, excessive carbides and coarse carbides occur, resulting in problems such as a decrease in the strength of the sintered alloy and an increase in the aggressiveness of the mating material. Therefore, C is set at 0.2 to 3.0%. (i) Co and Ni are dissolved in the matrix to particularly improve high-temperature strength and toughness, and also improve oxidation and corrosion resistance, as well as improve wear resistance.
Ni has no effect at less than 0.5%. Also, Co is 20%,
When Ni exceeds 10%, the improvement effect reaches a plateau.
Therefore, Co is preferably 2.0 to 20%, and Ni is preferably 0.5 to 10%. (j) Cu dissolves in the matrix to strengthen the matrix and increase its hardness, and also helps to make the precipitated carbide particles fine and uniform. Further, when infiltrating molten metal mainly composed of Cu, Cu also contributes to improving wettability and stabilizing the amount of infiltration. Its optimal range is 1-5
%. (k) Si has the effect of making carbides spheroidal and lowering the sintering temperature, but if it exceeds 1.5%, it is not preferable because it causes a decrease in sinterability and a decrease in strength. Mn has the effect of strengthening the matrix, but if it exceeds 0.5%, problems such as hardening of the powder and reduction in sinterability due to oxidation of the powder may occur. Therefore
Preferably, Si is 1.5% or less and Mn is 0.5% or less. (l) O is mainly contained in oxides and slag formed on the surface of the powder, and if it exceeds 0.5%, the sinterability will be significantly inhibited, so it is preferably 0.3% or less. (m) Among lubricating powders, when using Pb powder,
The amount used is preferably 0.2% to 10%. This is because if it is less than 0.2%, there will be no lubricating effect, and if it exceeds 10%, the base strength will be relatively reduced and the wear resistance will be reduced. On the other hand, in the case of MnS, the usage amount is 0.1 to 3
%. The reason for the limitation is the same as for Pb. The carbon in the sintered alloy is preferably supplied from alloy steel powder. The reason for this is that the sinterability is more stable than when graphite powder is supplied in the form of post-addition, and the pore distribution and carbide distribution are more uniform.
This is because dimensional accuracy is further improved. However, in special cases, a carbon source such as graphite powder is separately added to the carbon-containing alloy steel powder to deoxidize the powder during sintering and lower the sintering temperature. Good too. As a low melting point compound,
One or more of Cu 3 P, Fe 3 P, and Fe 2 B is used. [Example] The present invention will be explained in further detail in the following example. Note that the present invention is not limited to the following examples. Example 1 The base alloy steel powder contains Cr12%, C1.5%, and
Mo1%, V0.8%, Si0.2%, Mn0.3%, O0.04%,
Sprayed alloyed steel powder (-100 mesh) consisting of balance Fe and impurities of 1% or less was used. In addition, when the entire Cr alloy powder is taken as 100% by weight, the Cr alloy powder contains Co10%, W15%, Mo10%,
Sprayed alloy powder (-100 mesh) consisting of 10% Fe, 5.5% C, 0.4% O, balance Cr and impurities below 1%
was used. However, since some Cr-based alloy powders are hollowed out by entraining gas inside each individual powder when being sprayed, they may be pulverized using a ball mill or the like after being sprayed. and 100% by weight of the entire mixed powder
Cr-based alloy powder is added to the base alloy steel powder so that
10%, Fe3P powder 1.5% (-200 mesh), graphite powder 1.1% (-350 mesh), MnS powder 0.3
% and further zinc stearate as a lubricant
0.8% is added to form a mixed powder, and this mixed powder is compression molded at 7.0ton/ cm2 to form a mold with an inner diameter of 10mm and an outer diameter of 20mm.
mm, and the length was 20 mm. Next, this was heated at 1150° C. for 30 minutes in an ammonia decomposition gas atmosphere to perform sintering while generating a liquid phase to produce a test piece made of a sintered alloy. Examples 2 to 4 Test pieces were produced in the same manner as in Example 1, except for changing the component composition. Comparative Example A test piece was manufactured in the same manner as in Example 1, except that the Cr-based alloy powder was removed from the sample shown in Example 1. Tables 1 and 2 below show the compositions, blending ratios, and manufacturing conditions of the base alloy steel powder, Cr-based alloy powder, and other additive components in Examples 1 to 4 and Comparative Examples.
【表】【table】
【表】
性能比較試験
実施例１〜４及び比較例の試験片について、気
孔率、高温（600℃）圧環強さ及び高温耐摩耗性
を測定した。
気孔率はJIS Ｚ−2506により測定した。
高温圧環強さは、環状の試験片を２つの平行の
面が垂直となるように立てて上下に鋼板を押当て
接触線にかける荷重を増加して試験片に亀裂を生
じた時の荷重を圧環荷重とした。
高温耐摩耗性試験は、φ14mm、φ18mm、長さ15
mmの試験片を作製し、試験片を２mmの振幅で１分
間に1200回上下させ、その端面を面圧45Kgｆ／mm2
で平面状のバルブ相当材におし当て、さらにバル
ブ相当材を5rpmで回転させて行つた。又、バル
ブ相当材の表面は500℃に加熱され、ガソリンエ
ンジンの排気ガスを試験片接触部に導入して酸化
を防止した。尚、１回の試験時間は７時間とし
た。
実施例及び比較例の試験結果を表３に示す。[Table] Performance Comparison Test The porosity, high temperature (600°C) radial crushing strength, and high temperature abrasion resistance were measured for the test pieces of Examples 1 to 4 and Comparative Example. The porosity was measured according to JIS Z-2506. High-temperature radial crushing strength is measured by standing an annular test piece so that its two parallel surfaces are perpendicular, pressing steel plates on top and bottom, increasing the load applied to the contact line, and calculating the load at which cracks occur in the test piece. It was taken as the radial crushing load. High temperature abrasion resistance test was performed using φ14mm, φ18mm, length 15
A specimen of mm in diameter was prepared, and the specimen was moved up and down 1200 times per minute with an amplitude of 2 mm, and its end surface was subjected to a surface pressure of 45 Kgf/mm 2.
This was applied to a flat valve-equivalent material, and the valve-equivalent material was further rotated at 5 rpm. In addition, the surface of the valve-equivalent material was heated to 500°C, and exhaust gas from a gasoline engine was introduced into the test piece contact area to prevent oxidation. Note that the time for one test was 7 hours. Table 3 shows the test results of Examples and Comparative Examples.
上述の如く本発明の方法は、基地中に拡散・埋
設されて硬質粒子となるCr系合金粉末を原料成
分の１つとするため、従来の同種の焼結合金に比
べて高温耐摩耗性に非常に優れた焼結合金を容易
に得ることができ、例えばバルブシートに使用し
た場合にはその耐久性を向上させるので内燃機関
の性能向上に役立つ。又、本発明の方法において
は低融点化合物としてCu3P、Fe3P、Fe2Bの一種
以上を使用するため、部分液相が生じ易く、焼結
が促進される。
As mentioned above, the method of the present invention uses Cr-based alloy powder, which is diffused and buried in the matrix and becomes hard particles, as one of the raw materials, so it has extremely high temperature wear resistance compared to conventional sintered alloys of the same type. It is easy to obtain a sintered alloy with excellent properties, and when used in valve seats, for example, it improves the durability and is useful for improving the performance of internal combustion engines. Further, in the method of the present invention, one or more of Cu 3 P, Fe 3 P, and Fe 2 B is used as a low melting point compound, so a partial liquid phase is likely to occur and sintering is promoted.
Claims (1)
Mo2〜20％、Fe30％以下、C0.5〜７％、不可
避不純物１％以下及び残部Coからなる、基地
中に拡散・埋設されて硬質粒子となるCr系合
金粉末と、 重量比で、少なくともCr2.5〜25％、C0.2〜
3.0％、不可避不純物及び残部Feからなる合金
鋼粉末とCu3P、Fe3P、Fe2Bの一種以上からな
る低融点合金粉末とからなるFe系金属粉末と
を混合し成形体を形成する成形工程と、 (b) 該成形体を加熱して該成形体中に低融点の液
相を部分的に生ぜしめて液相焼結を行いつつ該
成形体の本焼結を行い、気孔率５％以下の焼結
合金を形成する焼結工程からなることを特徴と
する高温耐摩耗性に優れた焼結合金の製造方
法。 ２ Cr系合金粉末が重量比で５〜25％であるこ
とを特徴とする特許請求の範囲第１項記載の高温
耐摩耗性に優れた焼結合金の製造方法。 ３ 低融点合金粉末の代わりに、低融点合金粉末
とPb、MnSの一種以上からなる潤滑性粉末とを
混合した混合粉末を使用することを特徴とする特
許請求の範囲第１項記載の高温耐摩耗性に優れた
焼結合金の製造方法。 ４ 混合粉末中、Ｐが0.1〜0.8重量％であること
を特徴とする特許請求の範囲第３項記載の高温耐
摩耗性に優れた焼結合金の製造方法。 ５ 混合粉末が、Pb0.2〜10重量％、MnS0.1〜３
重量％のうち一種又は二種を含むことを特徴とす
る特許請求の範囲第３項記載の高温耐摩耗性に優
れた焼結合金の製造方法。 ６ 合金鋼粉末中の不可避不純物が重量比で0.3
％以下のＯ、1.5％以下のSi、0.5％以下のMn及
びその他の不純物１％以下からなることを特徴と
する特許請求の範囲第３項記載の高温耐摩耗性に
優れた焼結合金の製造方法。 ７ 合金鋼粉末が重量比でMo0.3〜6.5％、W0.5
〜12％、V0.25〜5.5％、Nb0.05〜３％のうち一
種又は二種以上を含み、且つMo、Ｗ、Ｖ、Nbの
合計が16％以下であることを特徴とする特許請求
の範囲第３項記載の高温耐摩耗性に優れた焼結合
金の製造方法。 ８ 合金鋼粉末が重量比でCo2.0〜20％、Ni0.5〜
10％、Cu1〜５％のうち一種又は二種以上を含
み、且つCo、Ni、Cuの合計が20％以下であるこ
とを特徴とする特許請求の範囲第３項記載の高温
耐摩耗性に優れた焼結合金の製造方法。 ９ Fe系金属粉末がグラフアイト粉末を含むこ
とを特徴とする特許請求の範囲第１項記載の高温
耐摩耗性に優れた焼結合金の製造方法。[Claims] 1 (a) In terms of weight ratio, Cr20~80%, W5~30%,
Cr-based alloy powder that becomes hard particles by being diffused and buried in the base, consisting of Mo2 ~ 20%, Fe 30% or less, C 0.5 ~ 7%, unavoidable impurities 1% or less, and the balance Co, and at least Cr2.5~25%, C0.2~
A compact is formed by mixing an alloy steel powder consisting of 3.0% Fe, unavoidable impurities, and the balance Fe-based metal powder consisting of a low melting point alloy powder consisting of one or more of Cu 3 P, Fe 3 P, and Fe 2 B. (b) main sintering of the compact while performing liquid phase sintering by heating the compact to partially generate a low melting point liquid phase in the compact, and 1. A method for producing a sintered alloy with excellent high-temperature wear resistance, the method comprising a sintering step for forming a sintered alloy with a sintered alloy of % or less. 2. The method for producing a sintered alloy with excellent high-temperature wear resistance according to claim 1, wherein the Cr-based alloy powder is 5 to 25% by weight. 3. The high temperature resistant device according to claim 1, characterized in that instead of the low melting point alloy powder, a mixed powder of a low melting point alloy powder and a lubricating powder made of one or more of Pb and MnS is used. A method for producing a sintered alloy with excellent wear resistance. 4. The method for producing a sintered alloy with excellent high-temperature wear resistance according to claim 3, characterized in that P in the mixed powder is 0.1 to 0.8% by weight. 5 The mixed powder contains 0.2 to 10% by weight of Pb and 0.1 to 3% by weight of MnS.
4. The method for producing a sintered alloy with excellent high-temperature wear resistance according to claim 3, characterized in that it contains one or two of the above by weight%. 6 Unavoidable impurities in alloy steel powder are 0.3 by weight
% or less of O, 1.5% or less of Si, 0.5% or less of Mn, and other impurities of 1% or less, according to claim 3. Production method. 7 Alloy steel powder has a weight ratio of Mo0.3 to 6.5% and W0.5
~12%, V0.25~5.5%, and Nb0.05~3%, and the total content of Mo, W, V, and Nb is 16% or less. A method for producing a sintered alloy with excellent high-temperature wear resistance according to item 3. 8 Alloy steel powder has a weight ratio of Co2.0~20% and Ni0.5~
10%, Cu, 1 to 5%, and the total content of Co, Ni, and Cu is 20% or less. Excellent method for producing sintered alloys. 9. The method for producing a sintered alloy with excellent high-temperature wear resistance according to claim 1, wherein the Fe-based metal powder contains graphite powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23850487A JPS6483640A (en) | 1987-09-22 | 1987-09-22 | Manufacture of sintered alloy having excellent high temperature wear resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23850487A JPS6483640A (en) | 1987-09-22 | 1987-09-22 | Manufacture of sintered alloy having excellent high temperature wear resistance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6483640A JPS6483640A (en) | 1989-03-29 |
| JPH0533299B2 true JPH0533299B2 (en) | 1993-05-19 |
Family
ID=17031233
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23850487A Granted JPS6483640A (en) | 1987-09-22 | 1987-09-22 | Manufacture of sintered alloy having excellent high temperature wear resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6483640A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH068490B2 (en) * | 1988-08-20 | 1994-02-02 | 川崎製鉄株式会社 | Sintered alloy with excellent specularity and method for producing the same |
| JP6668031B2 (en) * | 2014-09-30 | 2020-03-18 | 日本ピストンリング株式会社 | Iron-based sintered alloy material for sliding members |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5931851A (en) * | 1982-08-12 | 1984-02-21 | Nippon Piston Ring Co Ltd | Vane of rotary compressor |
| JPS6144152A (en) * | 1984-08-07 | 1986-03-03 | Teikoku Piston Ring Co Ltd | Manufacture of wear resistant sintered alloy |
| JPS6173865A (en) * | 1984-09-19 | 1986-04-16 | Toyota Motor Corp | Sintered iron alloy for valve seat |
| JPS6250451A (en) * | 1985-08-29 | 1987-03-05 | Japanese National Railways<Jnr> | Fe-base sintered material for sliding member |
| JPS62164858A (en) * | 1986-01-16 | 1987-07-21 | Toyota Motor Corp | Ferrous sintered alloy for valve seat |
-
1987
- 1987-09-22 JP JP23850487A patent/JPS6483640A/en active Granted
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5931851A (en) * | 1982-08-12 | 1984-02-21 | Nippon Piston Ring Co Ltd | Vane of rotary compressor |
| JPS6144152A (en) * | 1984-08-07 | 1986-03-03 | Teikoku Piston Ring Co Ltd | Manufacture of wear resistant sintered alloy |
| JPS6173865A (en) * | 1984-09-19 | 1986-04-16 | Toyota Motor Corp | Sintered iron alloy for valve seat |
| JPS6250451A (en) * | 1985-08-29 | 1987-03-05 | Japanese National Railways<Jnr> | Fe-base sintered material for sliding member |
| JPS62164858A (en) * | 1986-01-16 | 1987-07-21 | Toyota Motor Corp | Ferrous sintered alloy for valve seat |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6483640A (en) | 1989-03-29 |
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