JP2557870B2 - Manufacturing method of tough sintered member - Google Patents
Manufacturing method of tough sintered memberInfo
- Publication number
- JP2557870B2 JP2557870B2 JP62041453A JP4145387A JP2557870B2 JP 2557870 B2 JP2557870 B2 JP 2557870B2 JP 62041453 A JP62041453 A JP 62041453A JP 4145387 A JP4145387 A JP 4145387A JP 2557870 B2 JP2557870 B2 JP 2557870B2
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- Japan
- Prior art keywords
- weight
- nickel
- powder
- added
- sintering
- Prior art date
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Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は高い抗張力と靱性を有する強靱焼結部材の製
造方法に関するものである。The present invention relates to a method for producing a tough sintered member having high tensile strength and toughness.
（従来の技術） 従来、高強度焼結部材を製造するためには、原料粉と
して合金元素を選択することによりマトリックスを強化
し、更に焼入れによって組織をマルテンサイトにして高
強度化することが行なわれている。強化元素の一般的な
ものは炭素であり、焼結性向上のためニッケル、クロー
ム、モリブデン、銅などを適宜添加している。焼入れ
は、焼結後、焼結炉とは別の設備で処理するのが一般的
である。また、特公昭61-51003号公報に開示されている
ように、焼結後の冷却過程で液化窒素ガスを用いて冷却
する方法もあるが、液化窒素ガスの液送配管を設備する
必要があり、使用に当っては高圧ガス取締法により大幅
な規制を受けるという問題がある。また、焼入れ処理に
よって抗張力は増加するが、靱性、例えば衝撃値が大幅
に低下する問題がある。(Prior Art) Conventionally, in order to manufacture a high-strength sintered member, the matrix is strengthened by selecting an alloy element as a raw material powder, and further, the structure is made martensite by quenching to increase the strength. Has been. A general strengthening element is carbon, and nickel, chrome, molybdenum, copper, etc. are appropriately added to improve sinterability. After quenching, quenching is generally performed in a facility different from a sintering furnace. Further, as disclosed in Japanese Patent Publication No. 61-51003, there is a method of cooling using liquefied nitrogen gas in the cooling process after sintering, but it is necessary to install a liquid supply pipe for liquefied nitrogen gas. However, there is a problem in that it is subject to large restrictions under the High Pressure Gas Control Law. Further, although the tensile strength is increased by the quenching treatment, there is a problem that the toughness, for example, the impact value is significantly reduced.
また、主にニッケルや炭素を添加して、1250℃以上の
温度で焼結するいわゆる高温焼結も高強度焼結部材を得
るための方法として広く行なわれているが、焼結時の容
器や炉材の損傷が多く、結果的に製造コストを引き上げ
ているという問題がある。Also, so-called high temperature sintering, in which nickel or carbon is mainly added and sintering is performed at a temperature of 1250 ° C. or higher, is widely performed as a method for obtaining a high-strength sintered member. There is a problem that the furnace material is often damaged, resulting in an increase in manufacturing cost.
結局、特性的には、抗張力が高く、しかも靱性を低下
させず、製造コスト面では、1250℃を超えるような高い
焼結温度や、それに続く焼入工程を必要としない廉価な
製造コストで強靱焼結部材を製造し得る方法の出現が待
望されている。After all, in terms of characteristics, it has high tensile strength, does not lower toughness, and in terms of manufacturing cost, it is tough at a low sintering cost that does not require a high sintering temperature exceeding 1250 ° C and the subsequent quenching process. The advent of methods by which sintered parts can be produced is highly anticipated.
（発明が解決しようとする問題点） 本発明は、1250℃をこえる高温焼結や特別な焼入工程
を必要とせず、従来の焼結温度よりはやや高い1150℃〜
1250℃程度の焼結温度での焼結を主たる熱処理工程とす
るだけで強靱焼結部材を製造し得る方法を提供しようと
するものである。(Problems to be Solved by the Invention) The present invention does not require high temperature sintering exceeding 1250 ° C. or a special quenching step, and is slightly higher than the conventional sintering temperature of 1150 ° C.
An object of the present invention is to provide a method capable of producing a tough sintered member only by performing a main heat treatment step at a sintering temperature of about 1250 ° C.
（問題を解決するための手段） 本発明は、 （ａ） 主たる添加元素であるニッケルを、ニッケル添
加総量の50重量％〜80重量％をニッケル60〜70重量％−
銅15〜35重量％−モリブデン５〜15重量％の三元合金粉
で添加し、残りの20〜50重量％をニッケル粉単体で添加
し、ニッケル添加総量を４〜７重量％にし、 （ｂ） 炭素粉末を0.5〜1.0重量％添加し、 （ｃ） 1150℃〜1250℃で真空を含む非酸化性雰囲気中
で焼結し、焼結温度から10〜30℃／分の冷却速度で室温
まで冷却し、 （ｄ） 焼結後、−20℃以下でサブゼロ処理を施し、 （ｅ） サブゼロ処理後、120〜220℃で加熱処理するこ
とを特徴とする。(Means for Solving the Problem) The present invention provides (a) nickel, which is a main additive element, in an amount of 50 to 80% by weight based on the total amount of nickel added to 60 to 70% by weight of nickel.
Add 15 to 35% by weight of copper and 5 to 15% by weight of molybdenum as a ternary alloy powder, and add the remaining 20 to 50% by weight of nickel powder alone to make the total amount of nickel addition 4 to 7% by weight. ) Add 0.5 to 1.0% by weight of carbon powder, and (c) sinter at 1150 ° C to 1250 ° C in a non-oxidizing atmosphere including vacuum, and from the sintering temperature to room temperature at a cooling rate of 10 to 30 ° C / min. After cooling, (d) sintering, sub-zero treatment is performed at -20 ° C or lower, and (e) sub-zero treatment is followed by heat treatment at 120 to 220 ° C.
（作用） ニッケル粉の添加方法については、添加量すべてをニ
ッケル粉単体で添加すると、原料粉末の圧縮性、焼結体
の衝撃値については優位にあるが、ニッケルリッチ相の
存在により抗張力が低下する。他方、アトマイズ法など
でニッケル合金鋼粉とすると、抗張力は増加するが、原
料粉末の圧縮性、焼結体の衝撃値が低下する。(Function) Regarding the addition method of nickel powder, if the addition amount of nickel powder alone is added, the compressibility of the raw material powder and the impact value of the sintered body are superior, but the tensile strength decreases due to the presence of the nickel-rich phase. To do. On the other hand, when using nickel alloy steel powder by atomization or the like, the tensile strength increases, but the compressibility of the raw material powder and the impact value of the sintered body decrease.
本発明において、ニッケル添加総量の50〜80重量％
を、ニッケル60〜70重量％−銅15〜35重量％−モリブデ
ン５〜15重量％の三元合金粉で添加し、残りの20〜50重
量％をニッケル粉単体で添加する理由は、ニッケル60〜
70重量％−銅15〜35重量％−モリブデン５〜15重量％の
三元合金粉を添加したものは1150℃以上の焼結温度で液
相焼結となり、強靱化に寄与するという新たな知見に基
づくものである。In the present invention, 50 to 80% by weight of the total amount of nickel added
Is added as a ternary alloy powder of nickel 60 to 70% by weight-copper 15 to 35% by weight-molybdenum 5 to 15% by weight, and the remaining 20 to 50% by weight is added as a nickel powder alone. ~
A new finding that ternary alloy powder of 70 wt% -copper 15-35 wt% -molybdenum 5-15 wt% is liquid phase sintered at a sintering temperature of 1150 ° C or higher and contributes to toughness It is based on.
ニッケル分をニッケル単体で添加した場合には、焼結
温度を少なくとも1200℃以上、好ましくは1250℃以上の
高温にする必要があり、ニッケル−銅、いわゆるモネル
メタルで添加する方法も考えられるが、液相発生温度が
1200℃になるニッケル／銅の重量比率は20/80となり、
銅添加量が圧倒的に多くなり、その結果、衝撃値を低下
させ、焼結体の寸法変化も膨張側に移行するから、強靱
焼結部材を得るという目的にそぐわなくなり、さらに、
ニッケル−モリブデン二元合金も考えられるが、この合
金系は、いずれの割合でも、1300℃以下では溶融しない
という問題がある。When the nickel component is added as a simple substance of nickel, it is necessary to set the sintering temperature to a high temperature of at least 1200 ° C or higher, preferably 1250 ° C or higher, and a method of adding nickel-copper, so-called monel metal is also conceivable. Phase generation temperature is
The nickel / copper weight ratio at 1200 ° C is 20/80,
The amount of copper added becomes overwhelmingly large, as a result, the impact value is lowered, and the dimensional change of the sintered body also shifts to the expansion side, which defeats the purpose of obtaining a tough sintered member.
A nickel-molybdenum binary alloy is also conceivable, but this alloy system has a problem that it does not melt at 1300 ° C or lower in any proportion.
ニッケル−銅−モリブデン三元合金粉の添加量をニッ
ケル添加総量の50〜80重量％に限定した理由は、50％未
満の添加量では液相の発生量が充分ではなく希望する抗
張力が得られないので50重量％を下限とし、添加量が80
％を超えると抗張力は増加するが、衝撃値が低下するた
め、強度と靱性のバランスから80重量％を上限とした。The reason why the addition amount of nickel-copper-molybdenum ternary alloy powder is limited to 50 to 80% by weight of the total nickel addition amount is that when the addition amount is less than 50%, the amount of liquid phase generated is not sufficient and the desired tensile strength is obtained. 50% by weight is the lower limit, and the addition amount is 80
If the content exceeds 50%, the tensile strength increases, but the impact value decreases, so 80% by weight was made the upper limit from the balance of strength and toughness.
ニッケル添加総量を４〜７重量％に限定した理由は、
ニッケル量が４％未満では焼結後の冷却過程のみでは充
分強化せず、７％を超えて添加しても、８％ぐらいまで
は抗張力、衝撃値とも増加するが、その増加分はわずか
であり、ニッケル添加量がふえたことによる原料粉コス
ト上昇分とのバランスからみて得策ではないので、４％
を下限とし、７％を上限とした。The reason why the total amount of nickel added is limited to 4 to 7% by weight is as follows.
If the amount of nickel is less than 4%, it will not be sufficiently strengthened only by the cooling process after sintering, and if it is added in excess of 7%, both the tensile strength and the impact value will increase up to about 8%, but the increase will be small. Yes, it is not a good idea considering the balance with the increase in raw material powder cost due to the increase in the amount of nickel added, so 4%
Was the lower limit and 7% was the upper limit.
炭素粉末の添加量については通常、鉄−ニッケル系の
焼結部材の場合、最大抗張力を与える炭素量は0.5重量
％前後と考えられている。炭素添加量が0.8重量％を超
えると残留オーステナイト相の増加により抗張力は大幅
に低下する。Regarding the amount of carbon powder added, it is generally considered that in the case of an iron-nickel-based sintered member, the amount of carbon that gives the maximum tensile strength is around 0.5% by weight. When the amount of carbon added exceeds 0.8% by weight, the tensile strength is significantly reduced due to the increase in the retained austenite phase.
しかし、本発明においては通常実施されている最適炭
素添加量よりかなり多い0.5〜1.0重量％の炭素を添加
し、焼結後に発生した残留オーステナイトをサブゼロ処
理−加熱処理により微細なマルテンサイトにする。この
結果として、当然、衝撃値などの靱性の低下が懸念され
るが、前述したように一部ニッケル単体で加えたニッケ
ル粉が空孔の周囲にニッケルリッチ相として残ってお
り、さほどの靱性の低下をきたさない。したがって、炭
素粉末添加量を0.5〜1.0重量％に限定した理由は、0.5
％未満では焼結後の冷却のみでは充分強化せず、1.0％
を超えると衝撃値が大幅に低下し、圧粉体の密度も上昇
し難いからである。However, in the present invention, 0.5 to 1.0% by weight of carbon, which is considerably larger than the optimum amount of carbon that is usually used, is added, and residual austenite generated after sintering is made into fine martensite by subzero treatment-heat treatment. As a result, of course, there is concern that the toughness such as the impact value may decrease, but as described above, the nickel powder added as a part of nickel alone remains as the nickel-rich phase around the pores, and the toughness Does not cause a decline. Therefore, the reason for limiting the amount of carbon powder added to 0.5 to 1.0 wt% is 0.5
If it is less than 1.0%, it will not be sufficiently strengthened only by cooling after sintering, 1.0%
If it exceeds, the impact value will be significantly reduced and the density of the green compact will not easily increase.
焼結温度を1150〜1250℃に限定した理由は、1150℃よ
り低い温度では、前述したように液相焼結とはならず、
1250℃より高い焼結温度では抗張力および衝撃値は増加
するが、焼結容器や炉材の熱的損傷が大で、また、焼結
部材の収縮が大きくなり、寸法精度の確保が困難にな
り、量産性が低下するからである。The reason for limiting the sintering temperature to 1150 to 1250 ° C is that liquid temperature sintering does not occur at a temperature lower than 1150 ° C as described above.
The tensile strength and impact value increase at a sintering temperature higher than 1250 ° C, but the thermal damage to the sintering container and the furnace material is large, and the shrinkage of the sintered member becomes large, making it difficult to secure dimensional accuracy. This is because mass productivity is reduced.
焼結後の冷却速度を10〜30℃／分に限定した理由は、
冷却速度を10℃／分より遅くしたり30℃／分より速くす
るためには、通常の焼結炉に徐冷装置や急冷装置を付設
しなければならなくなるからである。The reason for limiting the cooling rate after sintering to 10 to 30 ° C / min is
This is because, in order to make the cooling rate slower than 10 ° C./min or faster than 30 ° C./min, it is necessary to attach a slow cooling device or a rapid cooling device to an ordinary sintering furnace.
サブゼロ処理の目的は、前述したように残留オーステ
ナイトをマルテンサイト化するためであり、処理温度を
−20℃以下に限定した理由は、これより高い温度では残
留オーステナイトが十分マルテンサイト化しないためで
ある。The purpose of the sub-zero treatment is to martensite the retained austenite as described above, and the reason for limiting the treatment temperature to -20 ° C or lower is that the retained austenite does not sufficiently martensite at higher temperatures. .
サブゼロ処理後の加熱処理を120〜220℃で行なう理由
は、マルテンサイトを微細化し、強靱性を向上させるた
めに行う処理温度の下限温度が120℃より低くては靱性
の向上が期待できず、上限温度が220℃を超えると抗張
力が低下するためである。The reason why the heat treatment after the sub-zero treatment is performed at 120 to 220 ° C. is that if the lower limit temperature of the treatment temperature performed to refine the martensite and improve the toughness is lower than 120 ° C., improvement of the toughness cannot be expected, This is because the tensile strength decreases when the maximum temperature exceeds 220 ° C.
（実施例） 以下、本発明の実施例について詳細に説明する。(Example) Hereinafter, the Example of this invention is described in detail.
第１表に示す本発明の実施例Ａ〜Ｎと、比較例Ｏ〜Ｗ
とによる引張試験片（JSPM標準準拠）および衝撃試験片
（JISシャルピーノッチなし）を作製し、その抗張力、
衝撃値および密度を調べた。Examples A to N of the present invention shown in Table 1 and Comparative Examples O to W
A tensile test piece (conforming to the JSPM standard) and an impact test piece (without JIS Charpy notch) were prepared using and their tensile strength,
The impact value and density were investigated.
本発明による実施例Ａ〜Ｈはアトマイズ鉄粉にアトマ
イズ法によりつくったニッケル65重量％−銅25重量％−
モリブデン10重量％の三元合金粉をニッケル分が４重量
％になるように添加し残りの２重量％はカーボニルニッ
ケル粉単体で添加した。また、炭素は天然黒鉛粉で0.5
〜1.0重量％添加した。 Examples A to H according to the present invention are 65% by weight of nickel prepared by the atomizing method on atomized iron powder-25% by weight of copper-
A ternary alloy powder containing 10% by weight of molybdenum was added so that the nickel content was 4% by weight, and the remaining 2% by weight was added as a carbonyl nickel powder alone. Also, carbon is 0.5 in natural graphite powder.
~ 1.0 wt% was added.
実施例I,Jはアトマイズ鉄粉に２重量％のカーボニル
ニッケル粉と天然黒鉛粉を0.8重量％加え、アトマイズ
法によりつくったニッケル65重量％−銅25重量％−モリ
ブデン10重量％の三元合金粉を、Ｉはニッケル分として
２重量％、Ｊはニッケル分として５重量％添加した。Examples I and J are ternary alloys of 65% by weight nickel, 25% by weight copper, and 10% by weight molybdenum prepared by the atomization method by adding 0.8% by weight of carbonyl nickel powder and 2% by weight of carbonyl nickel powder to atomized iron powder. The powder was added with 2% by weight of nickel as I and 5% by weight of nickel as J.
実施例Ｋはアトマイズ鉄粉にアトマイズ法によりつく
ったニッケル65重量％−銅25重量％−モリブデン10重量
％の三元合金粉をニッケル分が３重量％になるよう添加
し、残りの３重量％はカーボニルニッケル粉単体で添加
した。炭素は天然黒鉛粉で0.8重量％添加した。In Example K, ternary alloy powder of 65% by weight of nickel, 25% by weight of copper, and 10% by weight of molybdenum prepared by the atomizing method was added to atomized iron powder so that the nickel content was 3% by weight, and the remaining 3% by weight. Carbonyl nickel powder was added alone. Carbon was natural graphite powder and was added at 0.8% by weight.
実施例Ｌはアトマイズ鉄粉にアトマイズ法によりつく
ったニッケル65重量％−銅25重量％−モリブデン10重量
％の三元合金粉をニッケル分で4.8重量％になるよう添
加し、残りの1.2重量％はカーボニルニッケル粉単体で
添加した。In Example L, ternary alloy powder of 65% by weight of nickel, 25% by weight of copper, and 10% by weight of molybdenum produced by the atomizing method was added to atomized iron powder so that the content of nickel was 4.8% by weight, and the remaining 1.2% by weight. Carbonyl nickel powder was added alone.
実施例Ｍはアトマイズ鉄粉にアトマイズ法でつくった
ニッケル60重量％−銅35重量％−モリブデン５重量％の
三元合金粉をニッケル分で４重量％になるよう添加し、
残りの２重量％はカーボニルニッケル粉単体で添加し
た。In Example M, ternary alloy powder of 60% by weight of nickel, 35% by weight of copper and 5% by weight of molybdenum prepared by the atomization method was added to atomized iron powder so that the nickel content was 4% by weight.
The remaining 2% by weight was added as carbonyl nickel powder alone.
実施例Ｎはアトマイズ鉄粉にアトマイズ法によりつく
ったニッケル70重量％−銅15重量％−モリブデン15重量
％をニッケル分で４重量％になるよう添加し、残りの２
重量％はカーボニルニッケル粉単体で添加した。In Example N, 70% by weight of nickel produced by the atomizing method-15% by weight of copper-15% by weight of molybdenum was added to atomized iron powder so that the nickel content was 4% by weight.
Weight% was added as a carbonyl nickel powder alone.
実施例ＭおよびＮはいづれも炭素を、天然黒鉛粉で0.
8重量％添加した。In each of Examples M and N, carbon was used.
8 wt% was added.
比較例Ｏ〜Ｑはアトマイズ鉄粉にカーボニルニッケル
粉６重量％、電解銅粉1.5重量％、モリブデン還元粉0.6
重量％添加し、炭素は天然黒鉛粉で0.5〜0.8重量％添加
した。Comparative Examples O to Q are atomized iron powder, carbonyl nickel powder 6% by weight, electrolytic copper powder 1.5% by weight, molybdenum reducing powder 0.6%.
% By weight, and carbon was 0.5 to 0.8% by weight as natural graphite powder.
比較例Ｒ〜Ｔはニッケル、銅、モリブデンを鉄粉の周
囲に接合したいわゆる部分拡散合金鉄粉を用い、炭素は
天然黒鉛粉で0.5〜0.8重量％添加した。In Comparative Examples R to T, so-called partial diffusion alloy iron powder in which nickel, copper and molybdenum were bonded around the iron powder was used, and carbon was 0.5 to 0.8% by weight as natural graphite powder.
比較例Ｕ〜Ｗは焼結後、焼入れ、サブゼロ、加熱工程
を施さない例で比較例Ｕはアトマイズ鉄粉にアトマイズ
法によりつくったニッケル65重量％−銅25重量％−モリ
ブデン10重量％の三元合金粉をニッケル分で４重量％に
なるよう添加し、残りの２重量％はカーボニルニッケル
粉単体で添加した。炭素は天然黒鉛粉で1.0重量％添加
した。Comparative Examples U to W are examples in which quenching, sub-zero, and heating steps are not performed after sintering, and Comparative Example U is a mixture of atomized iron powder made of the atomized method with 65% by weight of nickel-25% by weight of copper-10% by weight of molybdenum. The original alloy powder was added so that the nickel content was 4% by weight, and the remaining 2% by weight was added as a carbonyl nickel powder alone. Carbon was natural graphite powder added at 1.0% by weight.
比較例Ｖはアトマイズ鉄粉にカーボニルニッケル粉を
６重量％、電解銅粉1.5重量％、モリブデン還元粉0.6重
量％を添加し、炭素は天然黒鉛粉で1.0重量％添加し
た。In Comparative Example V, 6 wt% of carbonyl nickel powder, 1.5 wt% of electrolytic copper powder and 0.6 wt% of reduced molybdenum powder were added to atomized iron powder, and carbon was 1.0 wt% of natural graphite powder.
比較例Ｗは比較例Ｒ〜Ｔと同じ部分拡散合金鉄粉であ
り、炭素は天然黒鉛粉で1.0重量％添加した。Comparative Example W was the same partial diffusion alloy iron powder as Comparative Examples R to T, and carbon was natural graphite powder added at 1.0% by weight.
上述した実施例および比較例Ａ〜Ｗのすべての原料粉
に0.8重量％のステアリン酸亜鉛を潤滑剤として添加
し、Ｖ型ミキサーで30分混合した。0.8% by weight of zinc stearate was added as a lubricant to all the raw material powders of Examples and Comparative Examples A to W described above, and they were mixed for 30 minutes with a V-type mixer.
混合後、所定の金型で７トン/cm2の圧力で成形し、容
積で80％の窒素ガスと容積で20％の水素ガスとの混合ガ
ス雰囲気中で、1150〜1250℃の温度に１時間加熱して焼
結した。焼結後、16℃／分の通常の冷却速度で常温まで
冷却した。焼結後、比較例ＰとＳは窒素ガス中で30分間
850℃に加熱後、油焼入れを行った。比較例Ｕ〜Ｗをの
ぞく実施例Ａ〜Ｎおよび比較例Ｏ〜Ｔは、−20〜−70℃
で１時間のサブゼロ処理後、120〜220℃で１時間加熱処
理を行った。After mixing, it is molded in a predetermined mold at a pressure of 7 ton / cm 2 , and in a mixed gas atmosphere of 80% by volume nitrogen gas and 20% by volume hydrogen gas at a temperature of 1150 to 1250 ° C. Heated and sintered for hours. After sintering, it was cooled to room temperature at a normal cooling rate of 16 ° C / min. After sintering, Comparative Examples P and S are for 30 minutes in nitrogen gas.
After heating to 850 ° C., oil quenching was performed. Examples A to N and Comparative Examples O to T except Comparative Examples U to W have a temperature of −20 to −70 ° C.
After sub-zero treatment for 1 hour, heat treatment was performed at 120 to 220 ° C. for 1 hour.
上述した処理を行った後の実施例Ａ〜Ｎと比較例Ｏ〜
Ｗによる試料の抗張力、衝撃値、密度を測定し、第２表
に示す。Examples A to N and Comparative Examples O to after performing the above-described processing
The tensile strength, impact value and density of the sample by W were measured and are shown in Table 2.
上述した表から明らかなように、本発明による実施例
Ａ〜Ｎは、比較例P,Sのような焼入処理を施さなくて
も、高い抗張力を有し、しかも高い衝撃値を有する強靱
焼結部材が得られている。 As is apparent from the above-mentioned table, Examples A to N according to the present invention have high tensile strength and high toughness without a quenching treatment like Comparative Examples P and S. A binding member is obtained.
次に、第１および２図に示す焼結歯車１を本発明によ
り製造する例につき説明する。Next, an example of manufacturing the sintered gear 1 shown in FIGS. 1 and 2 according to the present invention will be described.
アトマイズ鉄粉にアトマイズ法によりつくったニッケ
ル65重量％−銅25重量％−モリブデン10重量％よりなる
三元合金粉をニッケル分が4.5重量％になるように添加
し、1.5重量％のカーボニルニッケル粉を単体で添加し
て、更に天然黒鉛粉と潤滑剤としてステアリン酸亜鉛を
0.8重量％添加し、配合組成をFe-6Ni-1.7Cu-0.7Mo-0.6C
とし、金型を用いて成形密度が7.2g/cm3になるよう加圧
した後、容積で80％の窒素ガスと容積で20％の水素ガス
との混合ガス雰囲気中で１時間1250℃に加熱して焼結し
た。焼結後、通常の16℃／分の冷却速度で冷却した。Atomized ternary alloy powder consisting of 65% by weight of nickel, 25% by weight of copper, and 10% by weight of molybdenum made by the atomizing method was added to the iron powder so that the nickel content was 4.5% by weight, and 1.5% by weight of carbonyl nickel powder. Is added as a simple substance, and then natural graphite powder and zinc stearate as a lubricant are added.
0.8 wt% was added and the composition was Fe-6Ni-1.7Cu-0.7Mo-0.6C.
And pressurizing with a mold to a molding density of 7.2 g / cm 3 , and then at 1250 ° C for 1 hour in a mixed gas atmosphere of 80% by volume nitrogen gas and 20% by volume hydrogen gas. Heated and sintered. After sintering, it was cooled at a normal cooling rate of 16 ° C / min.
この部品を液化炭酸ガスにより−70℃に１時間保持し
てサブゼロ処理した後、大気中で180℃に１時間加熱処
理した。得られた部品の寸法（歯先系）および硬さ（HR
A）を測定し、第２図に示すように、測定台２上に歯車
１を載置し、矢Ａで示す方向に加圧して歯部強度を測定
した。その結果、歯先径の寸法バラツキ（３σ）は0.01
1mm、硬さはHRA68〜71、歯部強度は平均1560kgfであっ
た。This part was kept at −70 ° C. for 1 hour with liquefied carbon dioxide gas for subzero treatment, and then heat treated at 180 ° C. for 1 hour in the atmosphere. Dimension (tip system) and hardness (HR
A) was measured, and the gear 1 was placed on the measurement table 2 as shown in FIG. 2 and pressed in the direction indicated by arrow A to measure the tooth strength. As a result, the dimensional variation (3σ) of the tip diameter is 0.01.
The hardness was 1 mm, the hardness was HRA68-71, and the tooth strength was 1560 kgf on average.
一方、従来法で、既知の高強度焼結材料とされている
ニッケル−銅−モリブデンの部分拡散合金粉（Fe−４％
Ni-1.5％Cu-0.5％Mo）を7.2g/cm3の密度で成形し、上記
と同条件の1250℃焼結し、冷却した後、炭素濃度0.8％
のプロパン変成ガス中で900℃、２時間30分浸炭し、850
℃で30分拡散処理機、油冷し、その後、180℃で１時間
大気中で焼戻し処理を行って製造した。得られた部品の
歯先径の寸法バラツキ（３σ）は0.028mm、硬さはHRA66
〜73、歯部強度は平均1120kgfであった。On the other hand, in the conventional method, nickel-copper-molybdenum partial diffusion alloy powder (Fe-4%
Ni-1.5% Cu-0.5% Mo) was formed at a density of 7.2 g / cm 3, and 1250 ° C. sintering the same conditions, after cooling, the carbon concentration of 0.8%
In propane metamorphic gas at 900 ℃ for 2 hours 30 minutes, 850
It was manufactured by subjecting to a diffusion treatment machine at 30 ° C. for 30 minutes, oil cooling, and then tempering treatment at 180 ° C. for 1 hour in the atmosphere. The dimensional variation (3σ) of the tip diameter of the obtained parts is 0.028 mm, and the hardness is HRA66.
The average tooth strength was 1120kgf.
この実施例から明らかなように、本発明の方法によれ
ば、浸炭焼入工程を施さなくても高い強度を有し、浸炭
焼入れのような高温で再加熱する工程がないため、寸法
精度のよい高品質の部品が得られた。As is clear from this example, according to the method of the present invention, it has high strength without performing a carburizing and quenching step, and there is no step of reheating at a high temperature such as carburizing and quenching. Good quality parts were obtained.
（発明の効果） 本発明においては、ニッケル添加総量の50〜80重量％
をニッケル−銅−モリブデンの三元合金の形で添加する
ことにより、1250℃以下の焼結温度でもニッケルを主合
金元素とした鉄系高強度焼結部材の製造を可能とし、焼
結後、サブゼロ処理加熱処理を付加することにより、従
来、鉄−ニッケル系焼結部材の最適炭素量といわれてい
る0.5重量％よりかなり多い0.5〜1.0重量％の炭素添加
量を可能として抗張力を向上させ、これにより、1250℃
以下の焼結温度で、しかも、焼入工程を省略できること
から、従来の高強度焼結部材よりも低廉な製造コストで
寸法精度の高い強靱焼結部材を得ることができる。(Effect of the invention) In the present invention, 50 to 80 wt% of the total amount of nickel added
By adding nickel-copper-molybdenum in the form of a ternary alloy, it is possible to manufacture an iron-based high-strength sintered member containing nickel as the main alloying element even at a sintering temperature of 1250 ° C. or lower, and after sintering, By adding sub-zero treatment heat treatment, it is possible to increase the tensile strength by adding 0.5 to 1.0 wt% of carbon, which is considerably higher than 0.5 wt% which is conventionally said to be the optimum carbon amount of iron-nickel based sintered members. As a result, 1250 ℃
Since the quenching step can be omitted at the following sintering temperature, a tough sintered member having high dimensional accuracy can be obtained at a lower manufacturing cost than the conventional high-strength sintered member.
第１図は本発明の製造方法によって得られる焼結部材の
１例を示す平歯車の平面図、 第２図は第１図に示す平歯車の断面図、 第３図は平歯車の歯部強度測定方法を示す概略線図であ
る。 １……平歯車 ２……測定台FIG. 1 is a plan view of a spur gear showing an example of a sintered member obtained by the manufacturing method of the present invention, FIG. 2 is a sectional view of the spur gear shown in FIG. 1, and FIG. 3 is a tooth portion of the spur gear. It is a schematic diagram which shows the strength measuring method. 1 ... Spur gears 2 ... Measuring stand
Claims (1)
デン三元合金粉及び炭素粉末からなる鉄系粉末混合体を
用い、 （ａ） ニッケル添加総量の50重量％〜80重量％をニッ
ケル60〜70重量％−銅15〜35重量％−モリブデン５〜15
重量％の三元合金粉で添加し、残りの20重量％〜50重量
％をニッケル粉単体で添加してニッケル添加総量を４〜
７重量％とし、 （ｂ） 炭素粉末を0.5〜1.0重量％添加し、 （ｃ） 1150℃〜1250℃で非酸化性雰囲気中で焼結し、
焼結温度から室温まで10〜30℃／分の冷却速度で冷却
し、 （ｄ） 焼結後、−20℃以下でサブゼロ処理を施し、 （ｅ） サブゼロ処理後、120〜220℃で加熱処理するこ
とを特徴とする強靱焼結部材の製造方法。1. An iron-based powder mixture comprising iron powder, nickel powder, nickel-copper-molybdenum ternary alloy powder, and carbon powder is used. (A) Nickel 60 is added to 50% by weight to 80% by weight of the total amount of nickel added. ~ 70 wt% -Copper 15-35 wt% -Molybdenum 5-15
% Of ternary alloy powder is added, and the remaining 20% to 50% by weight is added to nickel powder alone to make the total nickel addition 4 to
7% by weight, (b) adding 0.5 to 1.0% by weight of carbon powder, (c) sintering at 1150 ° C to 1250 ° C in a non-oxidizing atmosphere,
Cool from the sintering temperature to room temperature at a cooling rate of 10 to 30 ° C / min. (D) After sintering, perform subzero treatment at -20 ° C or lower, and (e) After subzero treatment, heat treat at 120 to 220 ° C. A method for manufacturing a tough sintered member, comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62041453A JP2557870B2 (en) | 1987-02-26 | 1987-02-26 | Manufacturing method of tough sintered member |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62041453A JP2557870B2 (en) | 1987-02-26 | 1987-02-26 | Manufacturing method of tough sintered member |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63210252A JPS63210252A (en) | 1988-08-31 |
| JP2557870B2 true JP2557870B2 (en) | 1996-11-27 |
Family
ID=12608796
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62041453A Expired - Fee Related JP2557870B2 (en) | 1987-02-26 | 1987-02-26 | Manufacturing method of tough sintered member |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2557870B2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5834372B2 (en) * | 2013-06-20 | 2015-12-24 | 住友電工焼結合金株式会社 | Method for producing Fe-Cu-C sintered material |
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1987
- 1987-02-26 JP JP62041453A patent/JP2557870B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63210252A (en) | 1988-08-31 |
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