JPH0694562B2 - Method for producing composite alloy steel powder and sintered alloy steel - Google Patents
Method for producing composite alloy steel powder and sintered alloy steelInfo
- Publication number
- JPH0694562B2 JPH0694562B2 JP63244377A JP24437788A JPH0694562B2 JP H0694562 B2 JPH0694562 B2 JP H0694562B2 JP 63244377 A JP63244377 A JP 63244377A JP 24437788 A JP24437788 A JP 24437788A JP H0694562 B2 JPH0694562 B2 JP H0694562B2
- Authority
- JP
- Japan
- Prior art keywords
- alloy steel
- alloy
- powder
- weight
- strength
- 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 - Lifetime
Links
- 239000000843 powder Substances 0.000 title claims description 114
- 229910000851 Alloy steel Inorganic materials 0.000 title claims description 97
- 239000002131 composite material Substances 0.000 title claims description 51
- 238000004519 manufacturing process Methods 0.000 title claims description 21
- 229910045601 alloy Inorganic materials 0.000 claims description 52
- 239000000956 alloy Substances 0.000 claims description 52
- 239000000203 mixture Substances 0.000 claims description 51
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 43
- 229910052750 molybdenum Inorganic materials 0.000 claims description 37
- 229910052759 nickel Inorganic materials 0.000 claims description 37
- 238000005245 sintering Methods 0.000 claims description 36
- 229910000831 Steel Inorganic materials 0.000 claims description 35
- 239000010959 steel Substances 0.000 claims description 35
- 238000010791 quenching Methods 0.000 claims description 34
- 230000000171 quenching effect Effects 0.000 claims description 34
- 238000005496 tempering Methods 0.000 claims description 29
- 229910052799 carbon Inorganic materials 0.000 claims description 21
- 239000012535 impurity Substances 0.000 claims description 20
- 239000002245 particle Substances 0.000 claims description 20
- 238000005255 carburizing Methods 0.000 claims description 18
- 229910052721 tungsten Inorganic materials 0.000 claims description 14
- 239000012467 final product Substances 0.000 claims description 11
- 229910052742 iron Inorganic materials 0.000 claims description 9
- 238000004663 powder metallurgy Methods 0.000 claims description 7
- 229910000967 As alloy Inorganic materials 0.000 claims description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 52
- 238000010438 heat treatment Methods 0.000 description 28
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 15
- 230000000052 comparative effect Effects 0.000 description 12
- 238000009792 diffusion process Methods 0.000 description 11
- 238000000034 method Methods 0.000 description 11
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 10
- 238000004513 sizing Methods 0.000 description 10
- 229910001566 austenite Inorganic materials 0.000 description 8
- JKQOBWVOAYFWKG-UHFFFAOYSA-N molybdenum trioxide Chemical compound O=[Mo](=O)=O JKQOBWVOAYFWKG-UHFFFAOYSA-N 0.000 description 8
- 238000005204 segregation Methods 0.000 description 8
- 239000007789 gas Substances 0.000 description 7
- 238000000465 moulding Methods 0.000 description 7
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 7
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 6
- 238000005275 alloying Methods 0.000 description 6
- 238000005520 cutting process Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 229910021529 ammonia Inorganic materials 0.000 description 5
- 238000000354 decomposition reaction Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000000314 lubricant Substances 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- LFYJSSARVMHQJB-QIXNEVBVSA-N bakuchiol Chemical compound CC(C)=CCC[C@@](C)(C=C)\C=C\C1=CC=C(O)C=C1 LFYJSSARVMHQJB-QIXNEVBVSA-N 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 239000006104 solid solution Substances 0.000 description 4
- 238000005728 strengthening Methods 0.000 description 4
- 238000009864 tensile test Methods 0.000 description 4
- 238000009863 impact test Methods 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 229910000734 martensite Inorganic materials 0.000 description 3
- 229910000480 nickel oxide Inorganic materials 0.000 description 3
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 3
- 238000000137 annealing Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- ZNOKGRXACCSDPY-UHFFFAOYSA-N tungsten trioxide Chemical compound O=[W](=O)=O ZNOKGRXACCSDPY-UHFFFAOYSA-N 0.000 description 2
- 229910001339 C alloy Inorganic materials 0.000 description 1
- 229910003296 Ni-Mo Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 238000010273 cold forging Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- DDTIGTPWGISMKL-UHFFFAOYSA-N molybdenum nickel Chemical group [Ni].[Mo] DDTIGTPWGISMKL-UHFFFAOYSA-N 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、粉末冶金による焼結部品の製造に供される
合金鋼粉および焼結後に熱処理を施して使用される高強
度焼結合金鋼の製造方法に関するものである。Description: TECHNICAL FIELD The present invention relates to an alloy steel powder used in the production of a sintered component by powder metallurgy and a high-strength sintered alloy steel used after heat treatment after sintering. The present invention relates to a manufacturing method of.
鉄系焼結材料は自動車部品などに多く利用されている。
最近こられ部品の軽量化が指向され、高強度化が要望さ
れている。Iron-based sintered materials are widely used for automobile parts and the like.
Recently, there has been a demand for weight reduction of parts and higher strength.
焼結部品を高強度とするため、種々の合金鋼粉を用いる
とは周知の技術である。これらの高強度焼結合部品は、
高密度であることを要求されることが多い。完全に均一
な合金鋼粉は鋼粉粒子が固くなるので、鉄粉粒子表面に
合金元素の粉末を部分的に拡散付着させた、複合合金鋼
粉として、鋼粉の圧縮性を高める努力がなされている。It is a well-known technique to use various alloy steel powders in order to increase the strength of sintered parts. These high strength fired bonded parts
High density is often required. Since the steel powder particles become completely hard in a completely uniform alloy steel powder, efforts are made to improve the compressibility of the steel powder as a composite alloy steel powder in which the powder of the alloying element is partially diffused and adhered to the surface of the iron powder particles. ing.
しかし、このような複合合金鋼粉を用いる方法において
も、その合金組成や製造方法および使用方法が適切でな
い場合には、十分な焼結体特性を期待することができな
い。However, even in the method using such a composite alloy steel powder, if the alloy composition, the manufacturing method, and the usage method are not appropriate, sufficient sintered body properties cannot be expected.
特開昭61−231102号公報では、合金組成を高合金化する
ことによって、焼結材料の強度を高める試みがなされて
いる。しかし、Niを７％以上含む高合金組成であるた
め、コストが高いことのほか、焼結した状態で硬さが高
くなり、サイジングや切削加工が不可能となる。また焼
結後、残留オーステナイトが多くなり、引張強さを130k
gf/mm2以上の高強度とするためには、サブゼロ処理など
の特別の熱処が必要となってコスト上昇の要因になるな
ど問題が多い。また、残留オーステナイトが時間の経過
と共に分解し、部品の変形などの経時変化をもたらすこ
となども問題となる。In Japanese Patent Laid-Open No. 61-231102, an attempt is made to increase the strength of the sintered material by making the alloy composition high alloy. However, because of the high alloy composition containing 7% or more of Ni, the cost is high, and the hardness in the sintered state is high, which makes sizing and cutting impossible. After sintering, the retained austenite increased and the tensile strength was increased to 130k.
In order to achieve a high strength of gf / mm 2 or higher, there are many problems such as a special heat treatment such as sub-zero treatment, which causes a cost increase. Another problem is that the retained austenite decomposes over time, causing a change over time such as deformation of parts.
特公昭45−9649号公報では、成形後の熱処理に際して寸
法変化が少なく、高強度の焼結体を与える低合金鋼粉が
開示されている。この低合金鋼粉は鉄粉とNi、Moおよび
Cuの化合物との混合物を加熱して合金成分を拡散付着さ
せ、集合化した粒子を粉砕し、さらに焼鈍することによ
り得られるものである。しかし、この低合金鋼粉はCuを
0.50〜2.00重量％含んでおり、Cuが粒界に偏析してε−
Cu脆化層を生成し、機械的特性を劣化させるので、好ま
しくない。Japanese Examined Patent Publication No. 45-9649 discloses a low alloy steel powder which gives a sintered body of high strength with little dimensional change during heat treatment after forming. This low alloy steel powder consists of iron powder and Ni, Mo and
It is obtained by heating a mixture with a Cu compound to diffuse and adhere alloy components, crushing aggregated particles, and further annealing. However, this low alloy steel powder contains Cu
0.50 to 2.00% by weight, Cu is segregated at the grain boundaries and ε-
It is not preferable because it creates a Cu embrittlement layer and deteriorates mechanical properties.
また、本発明者らの一人は、特に焼結のままで、その後
の熱処理なしに用いられる場合に好適な、複合合金鋼粉
の組成を提案している（特開昭63−89601）。この合金
鋼粉はNiおよび／またはCuとMoとを含み、高い焼結体硬
さと焼結の際の寸法安定性を与える合金組成を有してい
る。しかし、焼結体の引張強さが130kgf/mm2以上を実現
しうるものではない。Further, one of the inventors of the present invention has proposed a composition of a composite alloy steel powder, which is suitable especially when it is used as it is without being heat treated (Japanese Patent Laid-Open No. 63-89601). This alloy steel powder contains Ni and / or Cu and Mo, and has an alloy composition that provides high sinter hardness and dimensional stability during sintering. However, the tensile strength of the sintered body cannot achieve 130 kgf / mm 2 or more.
さらに、本発明者らの一人らは、鋼粉表面に２種以上の
合金成が拡散付着され、かつ44μｍ以下の粒度における
各合金成分の含有量がそれぞれ鋼粉全体の平均含有量の
0.9〜1.9倍の範囲にある複合合金鋼粉を提案している
（特開昭61−130401号公報）。しかし、この合金鋼粉を
いて製造した焼結体は、引張時にオーステナイトからマ
ルテンサイトへの歪誘起変態が起こらず、また圧縮性不
足で密度が十分でないため、引張強さ130kgf/mm2以上を
実現することはできない。Furthermore, one of the inventors of the present invention has found that two or more alloy compositions are diffused and adhered to the surface of steel powder, and the content of each alloy component in the grain size of 44 μm or less is the average content of the entire steel powder.
A composite alloy steel powder in the range of 0.9 to 1.9 times has been proposed (Japanese Patent Laid-Open No. 61-130401). However, the sintered body produced by using this alloy steel powder does not undergo strain-induced transformation from austenite to martensite at the time of tensile, and since the density is not sufficient due to insufficient compressibility, a tensile strength of 130 kgf / mm 2 or more is required. It cannot be realized.
焼結部品に浸炭焼入れ処理を施したものは、部品内部の
靭性が高いと共に、表面部は硬くて耐摩耗性に富み、一
般に疲労強度も高い。従って、歯車などの高強度部品と
して最も実用的価値が高い。しかしながら、従来の焼結
体を単に浸炭焼入れするのみでは、引張強さ130kgf/mm2
以上の高強度を得ることは困難である。Sintered parts that have been subjected to carburizing and quenching treatment have high toughness inside the parts, a hard surface portion and excellent wear resistance, and generally high fatigue strength. Therefore, it has the highest practical value as a high-strength component such as a gear. However, if the conventional sintered body is simply carburized and quenched, the tensile strength will be 130 kgf / mm 2
It is difficult to obtain the above high strength.
問題のひとつは、焼結体が空孔を有するため、浸炭挙動
が通常の鋼材と異なり、適切な炭素濃度分布が得にくい
ことである。そのため強度が不十分となる。これを解決
するため、焼結体の密度を十分高めてから浸炭する試み
がなされた。焼結鍜造はそのひとつで、高強度材料が得
られている。しかし、この方法は特殊な設備を必要と
し、熱間鍜造に用いる金型の寿命が短いためコストが嵩
む場合が多く、適用は限定されている。One of the problems is that since the sintered body has pores, the carburizing behavior is different from that of ordinary steel materials, and it is difficult to obtain an appropriate carbon concentration distribution. Therefore, the strength becomes insufficient. In order to solve this, an attempt was made to carburize the sintered body after sufficiently increasing its density. Sintered manufacturing is one of them, and high-strength materials have been obtained. However, this method requires special equipment, and since the life of the mold used for hot working is short, the cost is often increased, and its application is limited.
一方、焼結体を冷間鋼造あるいはコイニングし、密度を
7.6〜7.8g/cm3と高めて高強度材を得ることも試みられ
た（特公昭49−16325号公報）。この方法は熱間鍜造設
備が不要であるという利点を持つが、7.6g/cm3以上の高
密度とするために、冷間鍜造またはコイニングの圧力を
高圧力とする必要があり、金型寿命が短いという問題を
有する。On the other hand, the sintered body is cold steel or coined to reduce its density.
Attempts were also made to obtain a high strength material by increasing it to 7.6 to 7.8 g / cm 3 (Japanese Patent Publication No. 49-16325). This method has the advantage that no hot forging equipment is required, but in order to achieve a high density of 7.6 g / cm 3 or higher, it is necessary to use cold forging or coining at a high pressure. There is a problem that the mold life is short.
さらに、熱処理を行う焼結部品において、高合金化、高
密度化により、高強度を得ている例は多い。しかし、特
開昭62−146203で開示された熱処理焼結体の引張強さは
120kgf/mm2以下であり、それ以上の高強度の要望に対し
ては満足できない。Further, in many cases, high strength is obtained in sintered parts that are heat-treated due to high alloying and high density. However, the tensile strength of the heat-treated sintered body disclosed in JP-A-62-146203 is
It is 120kgf / mm 2 or less, and we cannot meet the demand for higher strength.
また、特開昭54−50409では、密度が7.6g/cm3の焼結熱
処理材を製造し、引張強さ160kgf/mm2を得る技術が開示
されているが、衝撃値は2.5kgf/cm2以下であって、靭性
は低い。最近、焼結部品の高強度化に対する要請はます
ます強くなり、その結果、焼結後に熱処理を施す使用方
法が重要性を増している。この場合、熱処理後は焼結体
がきわめて硬くなるので、切削やサイジングによる寸法
矯正が困難となる。Further, JP-A-54-50409 discloses a technique for producing a sintered heat-treated material having a density of 7.6 g / cm 3 to obtain a tensile strength of 160 kgf / mm 2 , but an impact value of 2.5 kgf / cm. It is 2 or less and the toughness is low. Recently, the demand for higher strength of sintered parts has become stronger and stronger, and as a result, the method of using heat treatment after sintering has become more important. In this case, since the sintered body becomes extremely hard after the heat treatment, it becomes difficult to correct the dimension by cutting or sizing.
そこで、熱処理前にこれらの工程を加えることになるか
ら、切削やサイジングをできる限り容易にするように、
焼結体の熱処理前の硬さ従って強度を低くおさえ、その
後の熱処理で高強度（高硬度）とする必要がある。Therefore, since these steps will be added before heat treatment, in order to make cutting and sizing as easy as possible,
It is necessary to keep the hardness of the sintered body before heat treatment, that is, the strength low, and to make it high in strength (high hardness) by subsequent heat treatment.
これまでの複合合金鋼粉では、このような加工に適した
仕様が十分に検討されておらず、新しい仕様を有する合
金鋼粉の出現が待たれていたものである。With regard to the composite alloy steel powders to date, specifications suitable for such processing have not been sufficiently studied, and the appearance of alloy steel powders having new specifications has been awaited.
本発明の目的は、高合金組成とすることなく、また特殊
な設備を必要とすることなく、比較的低合金組成で高強
度、高靭性の焼結合金鋼を得るための粉末冶金用複合合
金鋼粉および熱処理焼結鋼の製造方法を提供することに
ある。このことによって焼結体の熱処理前の切削ないし
サイジングを容易にすると共に、焼結処理後に高強度、
高靭性の焼結体を得るという相反する技術を同時に実現
することができる。An object of the present invention is a composite alloy for powder metallurgy for obtaining a sintered alloy steel having a relatively low alloy composition, high strength and high toughness without requiring a high alloy composition and without requiring special equipment. It is intended to provide a method for producing steel powder and heat-treated sintered steel. This facilitates cutting or sizing of the sintered body before heat treatment, and high strength after sintering treatment,
The contradictory techniques of obtaining a high toughness sintered body can be realized at the same time.
本発明者らは、焼結体の高強度化ならびに高靭性化につ
いて鋭意研究した結果、用いる鋼粉の組成および焼結体
の密度の両者が焼結体の高強度化、高靭性化に著しく影
響することを見出した。The inventors of the present invention have conducted extensive studies on increasing the strength and toughness of the sintered body, and as a result, both the composition of the steel powder used and the density of the sintered body are remarkably high in strength and high toughness of the sintered body. It was found to affect.
本発明者らの着眼点は、Mi−Mo系複合合金鋼粉におい
て、焼結に引続いて浸炭焼入れを行う場合の組成を適正
化することである。すなわち、浸炭焼入れは、低炭素の
焼結鋼に炭素を拡散させながら焼入れする手法であるか
ら、熱処理前の切削性やサイジング性を与えるには、低
炭素の合金鋼として組成を選択し、その組成が熱処理
後、炭素を含む状態で所望の強度を与えるものであれば
よい。The present inventors' point of view is to optimize the composition of Mi-Mo-based composite alloy steel powder when carburizing and quenching is performed subsequent to sintering. That is, carburizing and quenching is a method of quenching carbon while diffusing carbon into a low carbon sintered steel, so to give machinability and sizing properties before heat treatment, select a composition as a low carbon alloy steel, Any composition may be used as long as it gives a desired strength in a state of containing carbon after heat treatment.
本発明者らの知見によれば、炭素が共存しない状態で
は、MoがNiに比べて焼結体を硬くしにくいため、熱処理
前の焼結体の切削やサイジングを考えた場合、Niよりも
自由に増量することができる。一方、浸炭後の強度上昇
にはMoはNiよりも寄与が大きい。そこで、これまでに存
在するNi−Mo系複合合金鋼粉の組成（MoをＷで置きかえ
た場合も含む）よりも、NiにくらべてMoをより多量に使
用することにより、きわめて良い結果が得られると考え
たのである。According to the knowledge of the present inventors, in the state where carbon does not coexist, Mo is less likely to harden the sintered body as compared with Ni, so when considering cutting or sizing of the sintered body before heat treatment, it is better than Ni. You can increase the amount freely. On the other hand, Mo contributes more to the increase in strength after carburizing than Ni. Therefore, by using a larger amount of Mo than Ni, compared to the composition of Ni-Mo composite alloy steel powder that has existed so far (including the case where Mo is replaced by W), extremely good results can be obtained. I thought it would be done.
本発明者らが得た焼結体の強度および靭性と組成および
密度との関係を述べる。The relationship between the strength and toughness of the sintered body obtained by the present inventors and the composition and density will be described.
NiとMoの含有量がそれぞれ、 （Ｘ）0.58％Ni−3.21％Mo （Ｙ）1.07％Ni−3.42％Mo （Ｚ）1.09％Ni−0.6％Mo の組成の複合合金鋼粉を用い、これに黒鉛と潤滑剤（ス
テアリン酸亜鉛）を添加し、仮焼結したのち、成形圧力
を変化して再圧縮を行い密度を変化させた。Ni and Mo contents are respectively (X) 0.58% Ni-3.21% Mo (Y) 1.07% Ni-3.42% Mo (Z) 1.09% Ni-0.6% Mo. Graphite and a lubricant (zinc stearate) were added to and calcined, and then the compacting pressure was changed to perform recompression to change the density.
その後、本焼結（1250℃×30分、アンモニア分解ガス
中）し、油焼入れ（870℃×60分、不活性ガス中加
熱）、180℃×60分の焼戻しを行った。これらの焼結体
の密度と引張強さおよびシャルビー衝撃値との関係を第
１図、第２図に示す。密度7.g/cm3以上で上記（Ｘ）、
（Ｙ）の焼結体は引張強さ130kgf/mm2以上を有するとに
高靭性であることがわかる。さらに、密度を7.3g/cm3以
上にすると、引張強さを150kgf/mm2以上にすることがで
きる。Then, main sintering (1250 ° C. × 30 minutes, in ammonia decomposition gas), oil quenching (870 ° C. × 60 minutes, heating in inert gas), and tempering at 180 ° C. × 60 minutes were performed. The relationships among the density, tensile strength and Charby impact value of these sintered bodies are shown in FIGS. 1 and 2. Above (X) with a density of 7.g / cm 3 or more,
It can be seen that the sintered body of (Y) has high toughness when it has a tensile strength of 130 kgf / mm 2 or more. Furthermore, when the density is 7.3 g / cm 3 or more, the tensile strength can be 150 kgf / mm 2 or more.
本発明は上記の知見をもとに構成されたものである。す
なわち本発明は、 （１）合金成分が粉末状に鉄粉粒子表面に部分的に拡散
付着された複合合金鋼粉において、合金成分として、Ni
とMoとを含み、合金組成が Ni:0.50〜3.50重量％ Mo:0.83〜3.50重量％ で、残部がFeおよび不可避不純物から成り、かつ該鋼粉
のうち45μｍ以下の粒度におけるNiおよびMoの含有量が
それぞれ該鋼粉全体の平均含有量の2.0〜4.2倍の範囲に
あることを特徴とする複合合金鋼粉。The present invention is based on the above findings. That is, the present invention provides (1) a composite alloy steel powder in which an alloy component is partially diffused and adhered to the surface of iron powder particles in a powder form, and Ni is used as an alloy component.
And Mo, the alloy composition is Ni: 0.50 to 3.50% by weight, Mo: 0.83 to 3.50% by weight, the balance is Fe and unavoidable impurities, and the content of Ni and Mo in the grain size of 45 μm or less in the steel powder. A composite alloy steel powder, characterized in that each amount is in the range of 2.0 to 4.2 times the average content of the entire steel powder.
（２）上記（１）に記載の複合合金鋼粉を用い、焼結後
浸炭焼入れ焼戻しを施し、最終製品合金成分としてNiと
Moとを含み、合金組成が Ni:0.50〜3.50重量％ Mo:0.83〜3.50重量％ で、残部がFe,Cおよび不可避不純物から成り、かつ密度
が7.0g/cm3以上で、浸炭焼入れ焼戻し後の引張強さが13
0kgf/mm2以上の高強度焼結合金鋼を製造することを特徴
とする焼結合金鋼の製造方法。(2) Using the composite alloy steel powder according to (1) above, after carburizing and quenching and tempering after sintering, Ni as the final product alloy component
It contains Mo and the alloy composition is Ni: 0.50 to 3.50 wt% Mo: 0.83 to 3.50 wt%, the balance is Fe, C and unavoidable impurities, and the density is 7.0 g / cm 3 or more. Has a tensile strength of 13
A method for producing a sintered alloy steel, which comprises producing a high-strength sintered alloy steel of 0 kgf / mm 2 or more.
（３）上記（１）に記載の複合合金鋼粉を用い、焼結後
焼入れ焼戻しを施し、最終製品合金成分としてＣ、Niと
Moとを含み、合金組成が C:0.3〜0.8重量％ Ni:0.50〜3.50重量％ Mo:0.83〜3.50重量％ で、残部がFeおよび不可避不純物から成り、かつ密度が
7.0g/cm3以上で、焼入れ焼戻し後の引張強さが130kgf/m
m2以上の高強度高靭性の焼結合金鋼を製造することを特
徴とする焼結合金鋼の製造方法。(3) Using the composite alloy steel powder according to (1) above, quenching and tempering are performed after sintering, and C and Ni are added as alloy components of the final product.
It contains Mo and the alloy composition is C: 0.3 to 0.8% by weight Ni: 0.50 to 3.50% by weight Mo: 0.83 to 3.50% by weight, the balance is Fe and inevitable impurities, and the density is
At 7.0g / cm 3 or more, the tensile strength after quenching and tempering is 130kgf / m
A method for producing a sintered alloy steel, which comprises producing a high-strength and high-toughness sintered alloy steel having a m 2 or more.
（４）合金成分が粉末状に鉄粉粒子表面に部分的に拡散
付着された複合合金鋼粉において、合金成分としてNiと
MoおよびＷとを含み、合金組成が Ni:0.50〜3.50重量％ Mo＋1/2W:0.83〜3.50重量％ で、残部がFeおよび不可避不純物から成り、かつ該鋼粉
のうち45μｍ以下の粒度におけるNiおよびMo＋1/2Wの含
有量がそれぞれ該鋼粉全体の平均含有量の2.0〜4.2倍の
範囲の粉末冶金用複合合金鋼粉。(4) Ni is used as an alloy component in the composite alloy steel powder in which the alloy component is partially diffused and adhered to the surface of the iron powder particles in powder form.
Including Mo and W, the alloy composition is Ni: 0.50 to 3.50 wt% Mo + 1 / 2W: 0.83 to 3.50 wt%, the balance is Fe and inevitable impurities, and Ni and Ni in a grain size of 45 μm or less of the steel powder. A composite alloy steel powder for powder metallurgy having a Mo + 1 / 2W content in the range of 2.0 to 4.2 times the average content of the entire steel powder.
（５）上記（４）に記載の複合合金鋼粉を用い、焼結後
浸炭焼入れ焼戻しを施し、最終製品合金成分がNiとMoお
よびＷとを含み、合金組成が Ni:0.50〜3.50重量％ Mo＋1/2W:0.83〜3.50重量％ で、残部がFe,Cおよび不可避不純物から成り、かつ密度
が7.0g/cm3以上で、浸炭焼入れ焼戻し後の引張強さが13
0kgf/mm2以上高強度焼結合金鋼を製造することを特徴と
する焼結合金鋼の製造方法。(5) Using the composite alloy steel powder according to (4) above, carburizing and quenching and tempering after sintering, the final product alloy component contains Ni, Mo and W, and the alloy composition is Ni: 0.50 to 3.50 wt% Mo + 1 / 2W: 0.83 to 3.50% by weight, the balance consisting of Fe, C and unavoidable impurities, density of 7.0 g / cm 3 or more, tensile strength after carburizing and tempering is 13
A method for producing a sintered alloy steel, which comprises producing a high-strength sintered alloy steel of 0 kgf / mm 2 or more.
（６）上記（４）に記載の複合合金鋼粉を用い、焼結後
焼入れ焼戻しを施し、最終製品合金成分がＣ、NiとMoお
よびＷとを含み、合金組成が C:0.3〜0.8重量％ Ni:0.50〜3.50重量％ Mo＋1/2W:0.83〜3.50重量％ で、残部がFeおよび不可避不純物から成り、かつ密度が
7.0g/cm3以上で、焼入れ焼戻し後の引張強さが130kgf/m
m2以上の高強度高靭性焼結合金鋼を製造することを特徴
とする焼結合金鋼の製造方法。(6) Using the composite alloy steel powder according to (4) above, after quenching and tempering after sintering, the final product alloy component contains C, Ni, Mo and W, and the alloy composition is C: 0.3 to 0.8 wt. % Ni: 0.50 to 3.50% by weight Mo + 1 / 2W: 0.83 to 3.50% by weight, the balance consisting of Fe and inevitable impurities, and the density
At 7.0g / cm 3 or more, the tensile strength after quenching and tempering is 130kgf / m
A method for producing a sintered alloy steel, characterized by producing a high-strength and high-toughness sintered alloy steel having a m 2 or more.
（７）合金成分が粉末状に鉄粉粒子表面に部分的に拡散
付着された複合合金鋼粉において、合金成分として、Ni
とＷとを含み、合金組成が Ni:0.50〜3.50重量％ W:1.30〜7.00重量％ で、残部がFeおよび不可避不純物から成り、かつ該鋼粉
のうち45μｍ以下の粒度におけるNiおよびＷの含有量が
それぞれ該鋼粉全体の平均含有量の2.0〜4.2倍の範囲で
あることを特徴とする粉末冶金用複合合金鋼粉。(7) In the composite alloy steel powder in which the alloy component is partially diffused and adhered to the surface of the iron powder particles in the form of powder, Ni is used as the alloy component.
And W, the alloy composition is Ni: 0.50 to 3.50% by weight, W: 1.30 to 7.00% by weight, the balance is Fe and inevitable impurities, and the content of Ni and W in the grain size of 45 μm or less in the steel powder. A composite alloy steel powder for powder metallurgy, characterized in that each amount is in a range of 2.0 to 4.2 times the average content of the entire steel powder.
（８）上記（７）に記載の複合合金鋼粉を用い、焼結後
浸炭焼入れ焼戻しを施し、最終製品合金成分としてNiと
Ｗとを含み、合金組成が Ni:0.50〜3.50重量％ W:1.30〜7.00重量％ で、残部がFe,Cおよび不可避不純物から成り、かつ密度
が7.0g/cm3以上で、浸炭焼入れ焼戻し後の引張強さが13
0kgf/mm2以上の高強度焼結合金鋼を製造することを特徴
とする焼結合金鋼の製造方法。(8) Using the composite alloy steel powder as described in (7) above, after carburizing and quenching and tempering after sintering, the final product contains Ni and W, and the alloy composition is Ni: 0.50 to 3.50 wt% W: 1.30 to 7.00% by weight, the balance consisting of Fe, C and unavoidable impurities, density of 7.0 g / cm 3 or more, and carburizing, quenching and tempering.
A method for producing a sintered alloy steel, which comprises producing a high-strength sintered alloy steel of 0 kgf / mm 2 or more.
（９）上記（７）に記載の複合合金鋼粉を用い、焼結後
焼入れ焼戻しを施し、最終製品合金成分としてＣ、Niと
Ｗとを含み、合金組成が C:0.3〜0.8重量％ Ni:0.50〜3.50重量％ W:1.30〜7.00重量％ で、残部がFeおよび不可避不純物から成り、かつ密度が
7.0g/cm3以上で、焼入れ焼戻し後の引張強さが130kgf/m
m2以上の高強度高靭性焼結合金鋼を製造することを特徴
とする焼結合金鋼の製造方法。(9) Using the composite alloy steel powder according to (7) above, after quenching and tempering after sintering, the final product contains C, Ni and W, and the alloy composition is C: 0.3 to 0.8 wt% Ni. : 0.50 to 3.50% by weight W: 1.30 to 7.00% by weight, the balance being Fe and inevitable impurities, and having a density
At 7.0g / cm 3 or more, the tensile strength after quenching and tempering is 130kgf / m
A method for producing a sintered alloy steel, characterized by producing a high-strength and high-toughness sintered alloy steel having a m 2 or more.
である。Is.
なお、本発明において複合合金鋼粉とは、鉄粉粒子表面
に合金元素、例えばNi,MoやＷが部分的に拡散付着され
た鋼粉を言う。In the present invention, the composite alloy steel powder refers to steel powder in which an alloying element such as Ni, Mo or W is partially diffused and adhered to the surface of iron powder particles.
上記数値限定の意義について説明する。The significance of the above numerical limitation will be described.
Ni:0.50〜3.50重量％ NiはFe基地に固溶して焼結体を強化し、また靭性を向上
させるのに役立つ。0.50重量％未満であると固溶強化お
よび焼入れ性向上による高強度化とマトリックスの靭性
改善効果が得られない。一方、3.50重量％を超えると、
過剰なオーステナイト相が生成し、強度低下が生じる。Ni: 0.50 to 3.50% by weight Ni serves as a solid solution in the Fe base to strengthen the sintered body and also serves to improve the toughness. If it is less than 0.50% by weight, it is impossible to obtain the effects of improving the strength and improving the toughness of the matrix by solid solution strengthening and improving the hardenability. On the other hand, if it exceeds 3.50% by weight,
Excessive austenite phase is generated, and strength is reduced.
Mo:0.83〜3.50重量％ MoはFe基地中に固溶し、焼結体を強化すると共に、炭物
を形成して強度および硬さを向上させるほか、焼入れ性
の上昇にも効果が大きい。Mo: 0.83 to 3.50 wt% Mo forms a solid solution in the Fe base, strengthens the sintered body, forms charcoal to improve strength and hardness, and has a great effect on increasing hardenability.
0.83重量％未満であると固溶強化および焼入れ性向上に
よる高強度化が得られない。一方、3.50重量％を超える
と靭性が阻害される。なお、Mo量は0.83重量％以上で高
強度が得られるが、0.85重量％以上にすると、一層の高
強度化達成でき好ましい。If it is less than 0.83% by weight, strengthening due to solid solution strengthening and improvement of hardenability cannot be obtained. On the other hand, if it exceeds 3.50% by weight, the toughness is impaired. It should be noted that high strength can be obtained when the amount of Mo is 0.83% by weight or more. However, when it is 0.85% by weight or more, further higher strength can be achieved, which is preferable.
以上、基本合金成分としてNiとMoについて述べたが、Mo
の一部または全部をその２倍の重量のＷで置きかえるこ
とができる。ここでＷの重量を２倍とするのは、焼結鋼
の特性変化に及ぼすＷの効果は、その1/2重量のMoの効
果に等しいからである。So far, Ni and Mo have been described as basic alloy components.
Can be partly or wholly replaced with twice its weight W. The reason why the weight of W is doubled here is that the effect of W on the change in the properties of the sintered steel is equal to the effect of Mo, which is 1/2 weight thereof.
C:0.3〜0.8重量％ Ｃは安価な強化元素であるが、熱処理焼結体のＣ量が0.
3重量％未満では、引張強さ130kgf/mm2以上の高強度が
得られない。多量含有すると炭化物を形成して強度靭性
を低下させ、またオーステナイト生成の要因となるた
め、熱処理焼結体のＣ量を0.3〜0.8重量％の範囲とし
た。Ｃ量の影について本発明者らが得た結果を、以下に
述べる。C: 0.3-0.8 wt% C is an inexpensive strengthening element, but the C content of the heat-treated sintered body is 0.
If it is less than 3% by weight, high strength of 130 kgf / mm 2 or more in tensile strength cannot be obtained. When a large amount is contained, a carbide is formed to reduce the strength and toughness, and it becomes a factor of austenite formation. Therefore, the C content of the heat-treated sintered body is set to the range of 0.3 to 0.8% by weight. The results obtained by the present inventors regarding the shadow of the C amount will be described below.
Ni,Moが上記範囲にある複合合金鋼粉について、製品Ｃ
量が0.1〜1.0重量％になるように黒鉛量を変えて添加
し、さらに潤滑剤として１重量％のステアリン酸亜鉛を
添加して混合粉を製造した。これらの鋼粉について成形
焼結した後、油焼入れ（870℃×30分）後180℃×60分焼
戻し熱処理焼結鋼を製造し、引張試験とシャルピー衝撃
試験を行った。その結果を第３図および第４図に示す。
Ｃ量が0.3〜0.8重量％の範囲において高強度、高靭性が
得られる。About the composite alloy steel powder with Ni and Mo in the above range, product C
The amount of graphite was changed so that the amount became 0.1 to 1.0% by weight, and 1% by weight of zinc stearate was added as a lubricant to prepare a mixed powder. After shaping and sintering these steel powders, oil-quenched (870 ° C x 30 minutes) and then 180 ° C x 60 minutes tempered heat-treated sintered steels were manufactured and subjected to a tensile test and a Charpy impact test. The results are shown in FIGS. 3 and 4.
High strength and high toughness are obtained when the C content is in the range of 0.3 to 0.8% by weight.
Ｃの添加は、部品の使用目的により焼結時に黒鉛粉を合
金鋼粉に混合して添加すると場合と、焼結後に浸炭焼入
れにより添加する場合がある。Depending on the purpose of use of the part, C may be added by mixing graphite powder with alloy steel powder at the time of sintering, or by carburizing and quenching after sintering.
浸炭焼入れの場合には、部品断面でＣ含有量の分布が生
じるが、Ｃ含有量は必ずしも全断面で上記範囲内にある
必要はなく、浸炭部において満足すれば良い。In the case of carburizing and quenching, the distribution of C content occurs in the cross section of the part, but the C content does not necessarily have to be within the above range in the entire cross section, and may be satisfied in the carburized portion.
高い密度の焼結製品を得るには、原料となる合金鋼粉の
圧縮性が高い必要がある。In order to obtain a sintered product with a high density, the alloy steel powder as a raw material needs to have high compressibility.
そのためには、NiとMoおよび／またはＷと鉄粉粒子表面
に拡散付着された、いわゆる複合合金鋼粉が適してい
る。完全に均一なプリアロイ鋼粉は、一般に圧縮性が低
く、高密度とするのに不利である。通常の鉄粉とNi粉、
Mo粉および／またはＷ粉との混合粉末では、焼結中の合
金元素の拡散が不十分で、強度の上昇が不十分である。
複合合金鋼粉であっても、拡散合金化の程度が低けれ
ば、やはり焼結体の強度が不足する。拡散合金化の進行
程度を見るため、合金鋼粉のうち45μｍ以下の粒度のも
のにおけるNiまたはMo＋1/2Wの含有量が鋼粉全体の平均
のNiまたはMo＋1/2Wの含有量のそれぞれ何倍であるかを
調べ、これを「拡散偏析度」として指標に用いる。For that purpose, so-called composite alloy steel powder, which is diffused and adhered to the surfaces of Ni and Mo and / or W and iron powder particles, is suitable. A completely uniform pre-alloyed steel powder generally has low compressibility and is disadvantageous for achieving high density. Normal iron powder and Ni powder,
In the mixed powder with Mo powder and / or W powder, the diffusion of alloying elements during sintering is insufficient and the increase in strength is insufficient.
Even with complex alloy steel powder, if the degree of diffusion alloying is low, the strength of the sintered body is also insufficient. In order to check the progress of diffusion alloying, the content of Ni or Mo + 1 / 2W in the alloy steel powder with a particle size of 45 μm or less should be several times that of the average Ni or Mo + 1 / 2W content of the entire steel powder. It is checked whether there is any, and this is used as an index as "diffusion segregation degree".
Ni,Mo＋1/2Wについてのこの拡散偏析度がそれぞれ4.2を
越えると、熱処理焼結体の強度および圧縮性が低下す
る。また、前述のように、拡散偏析度が2.0未満でも、
圧縮性が不足し、さらにオーステナイトがマルテンサイ
トに歪誘起変態しないため、引張強さが不十である。よ
って、拡散偏析度の範囲を2.0〜4.2とする。これは鉄粉
や合金成分の粒度およびこれらの加熱温度を調節するこ
とにより達成される。When the degree of diffusion segregation for Ni and Mo + 1 / 2W exceeds 4.2, the strength and compressibility of the heat-treated sintered body deteriorate. Further, as described above, even if the diffusion segregation degree is less than 2.0,
Since the compressibility is insufficient and the austenite does not undergo strain-induced transformation into martensite, the tensile strength is insufficient. Therefore, the range of the diffusion segregation degree is 2.0 to 4.2. This is achieved by adjusting the particle size of iron powder and alloy components and the heating temperature thereof.
複合合金鋼粉組成は、焼結体の組成に適合させて、Niが
0.50〜3.50重量％、Mo＋1/2Wが0.83〜3.50重量％、残部
Feと不可避不純物である。The composite alloy steel powder composition is adjusted to the composition of the sintered body, and Ni
0.50 to 3.50% by weight, Mo + 1 / 2W 0.83 to 3.50% by weight, balance
Fe and unavoidable impurities.
不純物の許容範囲は、 Ｃ :0.03重量％以内、好ましくは0.01重量％以内 Si:0.1重量％以内、好ましくは0.05重量％以内 Mn:0.4重量％以内、好ましくは0.15重量％以内 Cr:0.3重量％以内 Cu:0.3重量％以内 Al:0.1重量％以内 Ｐ :0.02重量％以内 Ｓ :0.02重量％以内 Ｏ :0.25重量％以内、好ましくは0.15重量％以内 Ｎ :0.01重量％以内、好ましくは0.002重量％以内 である。上記元素のうち、Mn、Crなどは、許容範囲以内
ならば、むしろ強度を向上させる場合があり、むやみに
低くすることばかりが得策ではない。The allowable range of impurities is C: 0.03 wt% or less, preferably 0.01 wt% or less Si: 0.1 wt% or less, preferably 0.05 wt% or less Mn: 0.4 wt% or less, preferably 0.15 wt% or less Cr: 0.3 wt% Cu: Within 0.3 wt% Al: Within 0.1 wt% P: Within 0.02 wt% S: Within 0.02 wt% O: Within 0.25 wt%, preferably within 0.15 wt% N: Within 0.01 wt%, preferably within 0.002 wt% Within Of the above elements, Mn, Cr, etc. may rather improve the strength if they are within the allowable range, and it is not a good idea to make them unnecessarily low.
また焼結体の強度確保のために複合合金鋼粉の粒度は、
180μｍ以上の粒度の重量割合を10％以内とすることが
好ましい。In order to secure the strength of the sintered body, the grain size of the composite alloy steel powder is
It is preferable that the weight ratio of particles having a particle size of 180 μm or more is within 10%.
次に熱処理について説明する。高強度を得るために、焼
結後、熱処理を行う。Next, the heat treatment will be described. In order to obtain high strength, heat treatment is performed after sintering.
熱処理は、表面付近で高硬度を得たい時は浸炭焼入れ焼
戻し処理を用いる。均一な強度を得たい時は焼結時に黒
鉛粉末により複合合金鋼粉にＣを添加し、通常の焼入れ
焼戻し処理を行う。この熱処理より、組織が焼戻しマル
テンサイトとなり、高強度、高靭性鋼が得られる。焼入
れ温度は800〜930℃が好ましく、800℃未満では加熱時
に均一なオーステナイト組織にならず、強度、靭性が低
下する。また、930℃を超えるとオーステナイトが粗大
化し、強度、靭性が低下する。For heat treatment, carburizing, quenching and tempering is used when high hardness is desired near the surface. When it is desired to obtain uniform strength, C is added to the composite alloy steel powder by graphite powder during sintering, and the usual quenching and tempering treatment is performed. By this heat treatment, the structure becomes tempered martensite, and high strength and high toughness steel is obtained. The quenching temperature is preferably 800 to 930 ° C. If it is less than 800 ° C., a uniform austenite structure is not formed during heating and the strength and toughness are reduced. On the other hand, if the temperature exceeds 930 ° C, the austenite becomes coarse and the strength and toughness decrease.
焼戻し温度は100〜250℃が好ましく、100℃未満では靭
性が低く、250℃を超えると強度が低下する。成形およ
び焼結は、密度向上のために、１回以上繰返しても良
い。The tempering temperature is preferably 100 to 250 ° C. If it is less than 100 ° C, the toughness is low, and if it exceeds 250 ° C, the strength is lowered. The molding and sintering may be repeated once or more to improve the density.
すなわち、成形−焼結−コイニング（サイジング）ある
いは、成形−予備焼結−コイニング（サイジング）−本
焼結といった再圧縮法が有用である。That is, a recompression method such as molding-sintering-coining (sizing) or molding-presintering-coining (sizing) -main sintering is useful.
実施例１〜３、比較例１〜３ はじめに原料となる複合合金鋼粉の製造について、実施
例と比較例を示す。まず、−80メッシュのアトマイズ純
鉄粉に、−325メッシュの酸化ニッケル粉末、−325メッ
シュの三酸化モリブデン粉を所定量混合し、水素ガス中
800℃で120分間加熱して、酸化ニッケルと三酸化モリブ
デンを還元し、鉄粉粒子のまわりにNiとMoを拡散付着さ
せた複合合金鋼粉を得た。Examples 1 to 3 and Comparative Examples 1 to 3 First, Examples and Comparative Examples of the production of the composite alloy steel powder as a raw material will be described. First, -80 mesh atomized pure iron powder is mixed with a predetermined amount of -325 mesh nickel oxide powder and -325 mesh molybdenum trioxide powder, and then mixed in hydrogen gas.
By heating at 800 ° C for 120 minutes, nickel oxide and molybdenum trioxide were reduced to obtain a composite alloy steel powder in which Ni and Mo were diffused and adhered around the iron powder particles.
「拡散偏析度」の影響を調べる目的で、上記純鉄粉に、
−325メッシュの金属Ni粉末および金属Mo粉末を所定量
混合し、水素ガス中の加熱温度を700℃、750℃、800
℃、850℃、1050℃と変化させて、複合合金鋼粉を作製
した。For the purpose of investigating the influence of "diffusion segregation degree",
-325 mesh metal Ni powder and metal Mo powder are mixed in a predetermined amount, and the heating temperature in hydrogen gas is 700 ℃, 750 ℃, 800 ℃.
℃, 850 ℃, changed to 1050 ℃, to produce composite alloy steel powder.
この複合合金鋼粉の組成は、 Ni:2.10〜2.18重量％ Mo:1.12〜1.23重量％ であり、ほかに、 Ｃ :0.002重量％ Si:0.04重量％ Mn:0.07重量％ Cu:0.01重量％ Ｐ :0.006重量％ Ｓ :0.006重量％ Ｏ :0.007〜0.13重量％ Ｎ :0.0007〜0.0019重量％ を含有していた。また、何れの鋼粉も180μｍ以上の粒
度の含有量は0.9〜2.5重量％であった。The composition of this composite alloy steel powder is Ni: 2.10 to 2.18 wt% Mo: 1.12 to 1.23 wt%, and in addition, C: 0.002 wt% Si: 0.04 wt% Mn: 0.07 wt% Cu: 0.01 wt% P : 0.006 wt% S: 0.006 wt% O: 0.007 to 0.13 wt% N: 0.0007 to 0.0019 wt% Further, the content of particles having a particle size of 180 μm or more was 0.9 to 2.5% by weight in all the steel powders.
これらの合金鋼粉に、潤滑剤としてステアリン酸亜鉛を
0.9重量％添加し、圧力7t/cm2で成形し、900℃で30分
間、水素ガス中で仮焼結し、7t/cm2でコイニングの後、
1250℃で90分間、水素ガス中で本焼結し、密度7.28〜7.
51g/cm3の焼結体を得た。Zinc stearate as a lubricant is added to these alloy steel powders.
0.9 wt% was added, molded at a pressure of 7 t / cm 2 , pre-sintered at 900 ° C. for 30 minutes in hydrogen gas, coined at 7 t / cm 2 ,
Main sintering in hydrogen gas at 1250 ℃ for 90 minutes, density 7.28 ~ 7.
A sintered body of 51 g / cm 3 was obtained.
これをカーボンポテンシャル0.8重量％、900で6.5時間
浸炭し、直ちに油焼入し、180℃で120分間焼戻した。強
度測定は、平行部5mmφの引張試験片によった。結果を
まとめて第１表に示す。This was carburized at 900% carbon potential and 900 for 6.5 hours, immediately oil-quenched, and tempered at 180 ° C for 120 minutes. The strength was measured by a tensile test piece having a parallel portion of 5 mmφ. The results are summarized in Table 1.
第１表に見られるように、拡散偏析度が2.0〜4.2の範囲
内であれば強度が大きい。As seen in Table 1, the strength is large when the diffusion segregation degree is in the range of 2.0 to 4.2.
実施例４〜15、比較例４〜６ アトマイズ純鉄粉に酸化ニッケルと三酸化モリブデンを
配合し、第２表に示すようなNi,Moおよび／またはＷ量
の異なる14種の複合合金鋼粉を作製した。合金鋼粉作製
時の加熱温度は800℃とした。さらに、Ni、MoおよびCu
を含む合金鋼粉を加熱温度850℃で作成した（比較例
６）。合金鋼粉の180μｍよりも粗い粒度の含有量は、
何れも0.5〜3.0重量％の範囲内であった。焼結浸炭およ
び焼入れ焼戻し条件は実施例１〜３と同様である。試験
結果をまとめて第２表に示す。 Examples 4 to 15 and Comparative Examples 4 to 6 Atomized pure iron powder was mixed with nickel oxide and molybdenum trioxide, and 14 kinds of composite alloy steel powders having different Ni, Mo and / or W contents as shown in Table 2 were obtained. Was produced. The heating temperature during the production of the alloy steel powder was 800 ° C. In addition, Ni, Mo and Cu
An alloy steel powder containing Al was prepared at a heating temperature of 850 ° C. (Comparative Example 6). The content of grain size coarser than 180 μm of alloy steel powder is
All were in the range of 0.5 to 3.0% by weight. Sinter carburizing and quenching and tempering conditions are the same as in Examples 1-3. The test results are summarized in Table 2.
第２表に見られるように、化学組成が Ni:0.50〜3.50重量％ Mo:0.83〜3.50重量％ の範囲内でかつ拡散偏析度が適切であれば、130kgf/mm2
以上の引張強さを示した。特にMoが0.85重量％以上がさ
らに好ましい結果を示した。As shown in Table 2, if the chemical composition is within the range of Ni: 0.50 to 3.50 wt% Mo: 0.83 to 3.50 wt% and the diffusion segregation degree is appropriate, 130 kgf / mm 2
The above tensile strengths are shown. Particularly, Mo was more preferable than 0.85% by weight.
実施例16〜23、比較例７ ここでは焼結密度と引張強さの関係について、実施例と
比較例をす。 Examples 16 to 23 and Comparative Example 7 Here, Examples and Comparative Examples will be described regarding the relationship between the sintered density and the tensile strength.
合金鋼粉としては、実施例１で用いた、2.15％Ni−1.18
％Mo複合合金鋼粉を使用した。この合金鋼粉に、黒鉛粉
を添加し、または添加せず、ステアリン酸亜鉛を0.9重
量％添加し、所定の圧力で第１次成形（通常の成形）を
行い、H2ガス中、所定の温度で60、第１次焼結（仮焼結
または通常の焼結）を行い、場合によって第２次の成形
（コイニングまたはサイジング）を所定の圧力で行い、
さらに場合によっては第２次の焼結（本焼結）を、H2ガ
ス中、1300℃で60分行い、実施例１と同じ条件で浸炭お
よび焼入れ焼戻しを施して、引張強さを測定した。結果
をまとめて第３表に示す。The alloy steel powder used in Example 1 was 2.15% Ni-1.18.
% Mo composite alloy steel powder was used. Graphite powder was added or not to this alloy steel powder, 0.9 wt% of zinc stearate was added, and primary molding (ordinary molding) was carried out at a predetermined pressure, in H 2 gas, at a predetermined At a temperature of 60, primary sintering (pre-sintering or normal sintering) is performed, and if necessary, secondary molding (coining or sizing) is performed at a predetermined pressure,
Further, in some cases, the second sintering (main sintering) was performed in H 2 gas at 1300 ° C. for 60 minutes, carburized and quenched and tempered under the same conditions as in Example 1, and the tensile strength was measured. . The results are summarized in Table 3.
このように密度は7.0g/cm3以上であれば、引張強さは13
0kgf/mm2が得られ、7.3g/cm3以上ならば一層高い強度が
得られた。Thus, if the density is 7.0 g / cm 3 or more, the tensile strength is 13
0 kgf / mm 2 was obtained, and higher strength was obtained at 7.3 g / cm 3 or more.
実施例24〜30、比較例８〜14 複合合金鋼粉を次の手順で作成した。原料鉄粉として、
水アトマイズ純鉄粉を用いた。粒度は−80メッシュ、化
学組成は C:0.002重量％ Si:0.03重量％ Mn:0.04重量％ Cu:0.01重量％ P:0.005重量％ S:0.007重量％ O:0.0086重量％ N:0.0008重量％ であった。合金原料としては、Niについては、カーボニ
ルニッケル粉、Moについては三酸化モリブデン（Mo
O3）、Ｗについては三酸化タングステン（WO3）を用い
た。いずれの合金成分原料も−325メッシュであった。 Examples 24 to 30 and Comparative Examples 8 to 14 Composite alloy steel powder was prepared by the following procedure. As raw iron powder,
Water atomized pure iron powder was used. Particle size is -80 mesh, chemical composition is C: 0.002% by weight Si: 0.03% by weight Mn: 0.04% by weight Cu: 0.01% by weight P: 0.005% by weight S: 0.007% by weight O: 0.0086% by weight N: 0.0008% by weight there were. As the alloy raw material, for Ni, carbonyl nickel powder, and for Mo, molybdenum trioxide (Mo
For O 3 ) and W, tungsten trioxide (WO 3 ) was used. The raw materials for all alloy components were -325 mesh.
鉄粉と合金成分原料とを後に示す所定の組成になるよう
に均一に混合し、水素ガス雰囲気中、850℃で60分加熱
し、鉄粉粒子に合金元素粉末を部分的に拡散付着させ、
その後解砕して、複合合金鋼粉とした。これらの合金鋼
粉に、ステアリン酸亜鉛１重量％を添加し、金型中成形
圧力6t/cm2で成形した。引続き、アンモニア分解ガス雰
囲気中、1250℃で60分の焼結を行って、焼結体を得た。
熱処理前の加工性を知るための指標として、これらの焼
結体の引張強さを求めた。The iron powder and the alloy component raw material are uniformly mixed so as to have a predetermined composition shown below, in a hydrogen gas atmosphere, heated at 850 ° C. for 60 minutes to partially diffuse and adhere the alloy element powder to the iron powder particles,
Then, it was crushed to obtain composite alloy steel powder. Zinc stearate (1% by weight) was added to these alloy steel powders and the mixture was molded in a mold at a molding pressure of 6 t / cm 2 . Subsequently, sintering was performed at 1250 ° C. for 60 minutes in an ammonia decomposition gas atmosphere to obtain a sintered body.
The tensile strength of these sintered bodies was determined as an index for knowing the workability before heat treatment.
次に焼結体の熱処理を行った。これは880℃においてカ
ーボンポテンシャル0.85％で200分の浸炭を行い、油中
に焼入れした。その後、180℃で60分の焼戻しを行っ
た。熱処理後の強度の指標として、引張強さを求めた。Next, the sintered body was heat-treated. This was carburized at 880 ° C for 200 minutes with a carbon potential of 0.85% and quenched in oil. Then, tempering was performed at 180 ° C. for 60 minutes. Tensile strength was determined as an index of strength after heat treatment.
作成した複合合金鋼粉の組成を第４表にまとめて示す。
実施例24〜30および比較例８〜13は、本発明の組成範囲
およびその周辺の組成を選んでおり、比較例14は従来の
標準的な複合合金鋼粉組成である。Table 4 shows the composition of the prepared composite alloy steel powder.
Examples 24 to 30 and Comparative Examples 8 to 13 selected the composition range of the present invention and compositions around it, and Comparative Example 14 was a conventional standard composite alloy steel powder composition.
第５表にこれらの鋼粉を試験した結果を示す。圧縮性は
6t/cm2の成形圧力で7.05g/cm2程度の密度が高密度焼結
体用鋼粉として望まれる。本発明の高Mo低Ni組成の熱処
理後の焼結体は、6t/cm2の成形圧力で107〜126kgf/mm2
の引張強さを示した。また、熱処理前の焼結体の引張強
さが40kgf/mm2程度以内ならば、切削やサイジングを困
難なく行うことができる。Table 5 shows the results of testing these steel powders. Compressibility
Density of about 7.05 g / cm 2 at a molding pressure of 6t / cm 2 is desirable as a high-density sintered-body steel powder. The high Mo low Ni composition sintered body of the present invention after heat treatment has a pressure of 6 t / cm 2 and a pressure of 107 to 126 kgf / mm 2.
The tensile strength of Further, if the tensile strength of the sintered body before heat treatment is within about 40 kgf / mm 2 , cutting and sizing can be performed without difficulty.
実施例Ａ〜Ｄ、比較例Ｆ〜Ｋ 何れも−325メッシュのNi粉、Mo酸化物粉（MoO3）を−8
0メッシュのFe粉と所定の割合で混合し、水素ガス雰囲
気中にて1000℃で１時間還元焼鈍後解砕して複合合金鋼
粉を製造した。この時の化学組成および拡散偏析度を第
６表に比較例と共に示す。 In each of Examples A to D and Comparative Examples F to K, Ni powder of 325 mesh and Mo oxide powder (MoO 3 ) were added to -8.
A 0-mesh Fe powder was mixed at a predetermined ratio, reduction annealing was performed at 1000 ° C. for 1 hour in a hydrogen gas atmosphere, and then crushed to produce a composite alloy steel powder. The chemical composition and the degree of diffusion segregation at this time are shown in Table 6 together with comparative examples.
これらの鋼粉に0.75重量％の黒鉛粉と潤滑剤としてのス
テアリン酸亜鉛を１重量％添加して、7t/cm2の圧力で成
形した。0.75% by weight of graphite powder and 1% by weight of zinc stearate as a lubricant were added to these steel powders and molded at a pressure of 7 t / cm 2 .
次に850℃で30分間アンモニア分解ガス雰囲気中で焼結
し、7t/cm2の圧力で再圧縮成形を行った。その後、1250
℃で30分間アンモニア分解ガス雰囲気中で焼結した。さ
らに870℃で60分間不活性ガス中で加熱し油焼入れ、引
き続き80℃で60分間オイルバス中で加熱し空冷する焼入
れ焼戻し処理を施し、引張試験とシャルピー衝撃試験に
供した。焼結体の化学組成、密度、引張強さおよび衝撃
値の実験結果を第７表に示す。Next, sintering was performed at 850 ° C. for 30 minutes in an atmosphere of ammonia decomposition gas, and recompression molding was performed at a pressure of 7 t / cm 2 . Then 1250
Sintering was carried out in an atmosphere of ammonia decomposition gas at 30 ° C for 30 minutes. Further, it was heated in an inert gas at 870 ° C. for 60 minutes for oil quenching, and subsequently subjected to quenching and tempering treatment in which it was heated at 80 ° C. for 60 minutes in an oil bath and air-cooled, and subjected to a tensile test and a Charpy impact test. Table 7 shows the experimental results of the chemical composition, density, tensile strength and impact value of the sintered body.
本発明範囲の化学組成および密度において150kgf/mm2以
上の引張強さと4kgf・m/cm2以上のシャルピー衝撃値を
示すことがわかる。It can be seen that the chemical composition and density within the range of the present invention show a tensile strength of 150 kgf / mm 2 or more and a Charpy impact value of 4 kgf · m / cm 2 or more.
実施例Ｌ〜Ｏ、比較例Ｑ〜Ｖ 第６表に示す複合合金鋼粉に、0.75重量％の黒鉛粉と潤
滑剤としてのステアリン酸亜鉛を１重量％添加して、7t
/cm2の圧力で成形し、1250℃で30分間アンモニア分解ガ
ス雰囲気中で焼結した。さらに870℃で60分間不活性ガ
ス中で加熱し油焼入れ、引き続き80℃で60分間オイルバ
ス中で加熱し空冷する焼入れ焼戻し処理を施し、引張試
験とシャルピー衝撃試験に供した。Examples L to O and Comparative Examples Q to V To the composite alloy steel powders shown in Table 6, 0.75% by weight of graphite powder and 1% by weight of zinc stearate as a lubricant were added to obtain 7t.
It was molded at a pressure of / cm 2 and sintered at 1250 ° C. for 30 minutes in an atmosphere of ammonia decomposition gas. Further, it was heated in an inert gas at 870 ° C. for 60 minutes for oil quenching, and subsequently subjected to quenching and tempering treatment in which it was heated at 80 ° C. for 60 minutes in an oil bath and air-cooled, and subjected to a tensile test and a Charpy impact test.
実験結果を第８表に示す。本発明の化学組成範囲におい
て、130kgf/mm2以上の引張強さと3.5kgf・m/cm2以上の
シャルピー衝撃値を示す。The experimental results are shown in Table 8. In the chemical composition range of the present invention, it exhibits a tensile strength of 130 kgf / mm 2 or more and a Charpy impact value of 3.5 kgf · m / cm 2 or more.
〔産業上の利用可能性〕 以上の説明から明らかなように、本発明の熱処理焼結鋼
は、極めて高い強度と靭性を兼ね備えるものであり、高
強度、高靭性が必要な焼結部品に有用である。本発明に
よる合金鋼粉は、今後の焼結部品の高強度化方向に合致
し、しかも高密度と加工性の両者が要求される場合に、
きわめて優れた適性を示すものである。従って、今まで
よりも高負荷で形状の複雑な機械部品を粉末冶金によっ
て製造することが容易になると考えられ、大きな効果を
期待することができる。 [Industrial Applicability] As is clear from the above description, the heat-treated sintered steel of the present invention has extremely high strength and toughness, and is useful for sintered parts that require high strength and high toughness. Is. The alloy steel powder according to the present invention conforms to the direction of higher strength of future sintered parts, and when both high density and workability are required,
It shows extremely excellent suitability. Therefore, it is considered that it becomes easier to manufacture a mechanical component having a complicated shape with a higher load than ever before by powder metallurgy, and a great effect can be expected.
第１図は本発明者らが得た熱処理焼結体の組成に対する
密度と引張強さとの関係を説明するグラフ、第２図は第
１図と同じ焼結体の組成に対する密度とシャルピー衝撃
値との関係を説明するグラフ、第３図はNi、Moの含有量
が本発明の範囲内にある熱処理焼結体のＣ量と引張強さ
との関係を説明するグラフ、第４図は第３図と同じ焼結
体のＣ量とシャルピー衝撃値との関係を説明するグラフ
である。FIG. 1 is a graph for explaining the relationship between the density and the tensile strength with respect to the composition of the heat-treated sintered body obtained by the present inventors, and FIG. 2 is the density and the Charpy impact value with respect to the composition of the same sintered body as in FIG. And FIG. 3 is a graph for explaining the relationship between the C content and the tensile strength of the heat-treated sintered body in which the contents of Ni and Mo are within the scope of the present invention, and FIG. It is a graph explaining the relationship between the C content and the Charpy impact value of the same sintered body as the figure.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 丸田 慶一 千葉県千葉市川崎町１番地 川崎製鉄株式 会社技術研究本部内 (72)発明者 阿部 輝宣 千葉県千葉市川崎町１番地 川崎製鉄株式 会社技術研究本部内 (72)発明者 桜田 一男 千葉県千葉市川崎町１番地 川崎製鉄株式 会社技術研究本部内 (56)参考文献 特開 昭61−64849（ＪＰ，Ａ) 特開 昭56−44702（ＪＰ，Ａ) 特開 昭52−44706（ＪＰ，Ａ) 特開 昭53−28012（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keiichi Maruta, 1 Kawasaki-cho, Chiba-shi, Chiba, Kawasaki Steel Co., Ltd. Technical Research Headquarters (72) Terunobu Abe 1 Kawasaki-cho, Chiba, Chiba Kawasaki Steel Co., Ltd. Technical Research Headquarters (72) Inventor Kazuo Sakurada 1 Kawasaki-cho, Chiba City, Chiba Prefecture Technical Research Headquarters, Kawasaki Steel Co., Ltd. (56) Reference JP-A-61-64849 (JP, A) JP-A-56-44702 ( JP, A) JP 52-44706 (JP, A) JP 53-28012 (JP, A)
Claims (9)
に拡散付着された複合合金鋼粉において、合金成分とし
て、NiとMoとを含み、合金組成が Ni:0.50〜3.50重量％ Mo:0.83〜3.50重量％ で、残部がFeおよび不可避不純物から成り、かつ該鋼粉
のうち45μｍ以下の粒度におけるNiおよびMoの含有量が
それぞれ該鋼粉全体の平均含有量の2.0〜4.2倍の範囲に
あることを特徴とする複合合金鋼粉。1. A composite alloy steel powder in which an alloy component is partially diffused and adhered to the surface of iron powder particles in a powder form, containing Ni and Mo as alloy components and having an alloy composition of Ni: 0.50 to 3.50% by weight. Mo: 0.83 to 3.50% by weight, the balance being Fe and unavoidable impurities, and the content of Ni and Mo in the grain size of 45 μm or less of the steel powder is 2.0 to 4.2 times the average content of the entire steel powder. A composite alloy steel powder characterized by being in the range of.
後浸炭焼入れ焼戻しを施し、最終製品合金成分としてNi
とMoとを含み、合金組成が Ni:0.50〜3.50重量％ Mo:0.83〜3.50重量％ で、残部がFe,Cおよび不可避不純物から成り、かつ密度
が7.0g/cm3以上で、浸炭焼入れ焼戻し後の引張強さが13
0kgf/mm3以上の高強度焼結合金鋼を製造することを特徴
とする焼結合金鋼の製造方法。2. The composite alloy steel powder according to claim 1, which is subjected to carburizing, quenching and tempering after sintering to obtain Ni as an alloy component of the final product.
And Mo, the alloy composition is Ni: 0.50 to 3.50% by weight, Mo: 0.83 to 3.50% by weight, the balance is Fe, C and unavoidable impurities, and the density is 7.0 g / cm 3 or more. Later tensile strength is 13
A method for producing a sintered alloy steel, which comprises producing a high-strength sintered alloy steel of 0 kgf / mm 3 or more.
後焼入れ焼戻しを施し、最終製品合金成分としてＣ、Ni
とMoとを含み、合金組成が C:0.3〜0.8重量％ Ni:0.50〜3.50重量％ Mo:0.83〜3.50重量％ で、残部がFeおよび不可避不純物から成り、かつ密度が
7.0g/cm3以上で、焼入れ焼戻し後の引張強さが130kgf/m
m2以上の高強度高靭性の焼結合金鋼を製造することを特
徴とする焼結合金鋼の製造方法。3. The composite alloy steel powder according to claim 1, which is subjected to quenching and tempering after sintering, and C and Ni as alloy components of the final product.
And Mo, the alloy composition is C: 0.3 to 0.8 wt% Ni: 0.50 to 3.50 wt% Mo: 0.83 to 3.50 wt%, the balance is Fe and inevitable impurities, and the density is
At 7.0g / cm 3 or more, the tensile strength after quenching and tempering is 130kgf / m
A method for producing a sintered alloy steel, which comprises producing a high-strength and high-toughness sintered alloy steel having a m 2 or more.
拡散付着された複合合金鋼粉において、合金成分として
NiとMoおよびＷとを含み、合金組成が Ni:0.50〜3.50重量％ Mo＋1/2W:0.83〜3.50重量％ で、残部がFeおよび不可避不純物から成り、かつ該鋼粉
のうち45μｍ以下の粒度におけるNiおよびMo＋1/2Wの含
有量がそれぞれ該鋼粉全体の平均含有量の2.0〜4.2倍の
範囲にあることを特徴とする粉末冶金用複合合金鋼粉。4. A composite alloy steel powder in which an alloy component is partially dispersed and adhered to the surface of iron powder particles in a powder form,
Including Ni, Mo and W, the alloy composition is Ni: 0.50 to 3.50 wt% Mo + 1 / 2W: 0.83 to 3.50 wt%, the balance is Fe and unavoidable impurities, and the grain size of the steel powder is 45 μm or less. A composite alloy steel powder for powder metallurgy, characterized in that the contents of Ni and Mo + 1 / 2W are respectively 2.0 to 4.2 times the average contents of the entire steel powder.
炭焼入れ焼戻しを施し、最終製品合金成分がNiとMoおよ
びＷとを含み、合金組成が Ni:0.50〜3.50重量％ Mo＋1/2W:0.83〜3.50重量％ で、残部がFe,Cおよび不可避不純物から成り、かつ密度
が7.0g/cm3以上で、浸炭焼入れ焼戻し後の引張強さが13
0kgf/mm2以上の高強度焼結合金鋼を製造することを特徴
とする焼結合金鋼の製造方法。5. The composite alloy according to claim 4, which is subjected to carburizing quenching and tempering after sintering, the final product alloy component contains Ni, Mo and W, and the alloy composition is Ni: 0.50 to 3.50 wt% Mo + 1 / 2W: 0.83 to 3.50% by weight, the balance consisting of Fe, C and unavoidable impurities, density of 7.0 g / cm 3 or more, tensile strength after carburizing and tempering is 13
A method for producing a sintered alloy steel, which comprises producing a high-strength sintered alloy steel of 0 kgf / mm 2 or more.
後焼入れ焼戻しを施し、最終製品合金成分がＣ、NiとMo
およびＷとを含み、合金組成が C:0.3〜0.8重量％ Ni:0.50〜3.50重量％ Mo＋1/2W:0.83〜3.50重量％ で、残部がFeおよび不可避不純物から成り、かつ密度が
7.0g/cm3以上で、焼入れ焼戻し後の引張強さが130kgf/m
m2以上の高強度高靭性焼結合金鋼を製造することを特徴
とする焼結合金鋼の製造方法。6. The composite alloy steel powder according to claim 4, which is subjected to quenching and tempering after sintering so that the final alloy components are C, Ni and Mo.
And W, the alloy composition is C: 0.3 to 0.8% by weight Ni: 0.50 to 3.50% by weight Mo + 1 / 2W: 0.83 to 3.50% by weight, the balance is Fe and inevitable impurities, and the density is
At 7.0g / cm 3 or more, the tensile strength after quenching and tempering is 130kgf / m
A method for producing a sintered alloy steel, characterized by producing a high-strength and high-toughness sintered alloy steel having a m 2 or more.
に拡散付着された複合合金鋼粉において、合金成分とし
て、NiとＷとを含み、合金組成が Ni:0.50〜3.50重量％ W:1.30〜7.00重量％ で、残部がFeおよび不可避不純物から成り、かつ該鋼粉
のうち45μｍ以下の粒度におけるNiおよびＷの含有量が
それぞれ該鋼粉全体の平均含有量の2.0〜4.2倍の範囲に
あることを特徴とする粉末冶金用複合合金鋼粉。7. A composite alloy steel powder in which an alloy component is partially diffused and adhered to the surface of iron powder particles in a powder form, containing Ni and W as alloy components and having an alloy composition of Ni: 0.50 to 3.50% by weight. W: 1.30 to 7.00% by weight, the balance consisting of Fe and unavoidable impurities, and the content of Ni and W in the grain size of 45 μm or less of the steel powder is 2.0 to 4.2 times the average content of the entire steel powder. A composite alloy steel powder for powder metallurgy, characterized in that
後浸炭焼入れ焼戻しを施し、最終製品合金成分としてNi
とＷとを含み、合金組成が Ni:0.50〜3.50重量％ W:1.30〜7.00重量％ で、残部がFe,Cおよび不可避不純物から成り、かつ密度
が7.0g/cm3以上で、浸炭焼入れ焼戻し後の引張強さが13
0kgf/mm2以上の高強度焼結合金鋼を製造することを特徴
とする焼結合金鋼の製造方法。8. The composite alloy steel powder according to claim 7, which is subjected to carburizing quenching and tempering after sintering to obtain Ni as a final product alloy component.
And W, the alloy composition is Ni: 0.50 to 3.50% by weight W: 1.30 to 7.00% by weight, the balance is Fe, C and unavoidable impurities, and the density is 7.0 g / cm 3 or more. Later tensile strength is 13
A method for producing a sintered alloy steel, which comprises producing a high-strength sintered alloy steel of 0 kgf / mm 2 or more.
後焼入れ焼戻しを施し、最終製品合金成分としてＣ、Ni
とＷとを含み、合金組成が C:0.3〜0.8重量％ Ni:0.50〜3.50重量％ W:1.30〜7.00重量％ で、残部がFeおよび不可避不純物から成り、かつ密度が
7.0g/cm3以上で、焼入れ焼戻し後の引張強さが130kgf/m
m2以上の高強度高靭性焼結合金鋼を製造することを特徴
とする焼結合金鋼の製造方法。9. A composite alloy steel powder as set forth in claim 7, which is subjected to quenching and tempering after sintering to obtain C and Ni as alloy components of the final product.
And W, the alloy composition is C: 0.3 to 0.8 wt% Ni: 0.50 to 3.50 wt% W: 1.30 to 7.00 wt%, the balance is Fe and inevitable impurities, and the density is
At 7.0g / cm 3 or more, the tensile strength after quenching and tempering is 130kgf / m
A method for producing a sintered alloy steel, characterized by producing a high-strength and high-toughness sintered alloy steel having a m 2 or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63244377A JPH0694562B2 (en) | 1987-09-30 | 1988-09-30 | Method for producing composite alloy steel powder and sintered alloy steel |
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62-244074 | 1987-09-30 | ||
| JP24407487 | 1987-09-30 | ||
| JP63-137400 | 1988-06-06 | ||
| JP13740088 | 1988-06-06 | ||
| JP63244377A JPH0694562B2 (en) | 1987-09-30 | 1988-09-30 | Method for producing composite alloy steel powder and sintered alloy steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0297602A JPH0297602A (en) | 1990-04-10 |
| JPH0694562B2 true JPH0694562B2 (en) | 1994-11-24 |
Family
ID=27317463
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63244377A Expired - Lifetime JPH0694562B2 (en) | 1987-09-30 | 1988-09-30 | Method for producing composite alloy steel powder and sintered alloy steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0694562B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05117703A (en) * | 1991-09-05 | 1993-05-14 | Kawasaki Steel Corp | Iron-base powder composition for powder metallurgy, its production and production of iron-base sintering material |
| JP6309215B2 (en) * | 2013-07-02 | 2018-04-11 | Ntn株式会社 | Sintered machine part manufacturing method and mixed powder used therefor |
| CN105855555B (en) * | 2016-04-05 | 2018-05-11 | 广东省钢铁研究所 | A kind of preparation method of iron cobalt magnetically soft alloy device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4004889A (en) * | 1975-10-06 | 1977-01-25 | Caterpillar Tractor Co. | Powdered metal article having wear resistant surface |
| US4069044A (en) * | 1976-08-06 | 1978-01-17 | Stanislaw Mocarski | Method of producing a forged article from prealloyed-premixed water atomized ferrous alloy powder |
| US4287068A (en) * | 1978-06-14 | 1981-09-01 | Metallurgical International, Inc. | Powdered metal filter composition and processes for producing the same |
| JPS6164849A (en) * | 1984-09-06 | 1986-04-03 | Toyota Motor Corp | High strength iron sintered alloy |
-
1988
- 1988-09-30 JP JP63244377A patent/JPH0694562B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0297602A (en) | 1990-04-10 |
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