JPS5887252A - Alloy steel powder for sintered machine parts with high strength and toughness - Google Patents
Alloy steel powder for sintered machine parts with high strength and toughnessInfo
- Publication number
- JPS5887252A JPS5887252A JP56186217A JP18621781A JPS5887252A JP S5887252 A JPS5887252 A JP S5887252A JP 56186217 A JP56186217 A JP 56186217A JP 18621781 A JP18621781 A JP 18621781A JP S5887252 A JPS5887252 A JP S5887252A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- steel
- sintered
- toughness
- 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.)
- Pending
Links
- 239000000843 powder Substances 0.000 title claims abstract description 70
- 229910000851 Alloy steel Inorganic materials 0.000 title claims abstract description 5
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 13
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 13
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 12
- 229910000831 Steel Inorganic materials 0.000 abstract description 82
- 239000010959 steel Substances 0.000 abstract description 82
- 229910052799 carbon Inorganic materials 0.000 abstract description 12
- 229910052760 oxygen Inorganic materials 0.000 abstract description 11
- 229910052748 manganese Inorganic materials 0.000 abstract description 9
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 229910052721 tungsten Inorganic materials 0.000 abstract description 5
- 229910052751 metal Inorganic materials 0.000 abstract description 2
- 239000007858 starting material Substances 0.000 abstract 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 28
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 16
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 14
- 239000002245 particle Substances 0.000 description 14
- 230000000052 comparative effect Effects 0.000 description 12
- 239000011148 porous material Substances 0.000 description 12
- 238000005245 sintering Methods 0.000 description 12
- 238000005275 alloying Methods 0.000 description 11
- 229910045601 alloy Inorganic materials 0.000 description 9
- 239000000956 alloy Substances 0.000 description 9
- 230000006872 improvement Effects 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 239000007791 liquid phase Substances 0.000 description 7
- 239000001301 oxygen Substances 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 230000008859 change Effects 0.000 description 5
- 229910052742 iron Inorganic materials 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 150000001247 metal acetylides Chemical class 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 229910001020 Au alloy Inorganic materials 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 239000003353 gold alloy Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000004663 powder metallurgy Methods 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 230000009257 reactivity Effects 0.000 description 2
- 238000005204 segregation Methods 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 229910000746 Structural steel Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- -1 carbon carbides Chemical class 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 238000010309 melting process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
Abstract
Description
【発明の詳細な説明】
り、とくに圧密材（焼結鋼，粉末鍛造鋼を以下圧・密林
°と総称する。）の焼入性と焼結鋼の強度，靭性に優れ
たアトマイズ鋼粉に関するものである。[Detailed description of the invention] In particular, it relates to an atomized steel powder that has excellent hardenability of compacted materials (sintered steel and powder forged steel are hereinafter collectively referred to as pressure and jungle °), strength and toughness of sintered steel. It is something.
近年、焼結機械部品の生産は、次第・に高強度部品の領
域Ｋ及びつつあり、それに伴なって低摩でされるようＫ
なった。In recent years, the production of sintered machine parts has gradually moved into the area of high-strength parts, and along with this, the production of sintered machine parts has been moving into the area of high-strength parts.
became.
通常、焼結機械部品の高強度化を図るため、純鉄粉に銅
粉やニッケル粉と黒鉛粉を混合して成形、焼結し、必要
に応じて熱処理したり、あるいは、Ｍｎ 、 Ｃｒ 、
Ｍｏ 、 Ｖの／ａ［または一種以上を合金した銅粉
、あるいは、 Ｎｉ 、 Ｃｕ ＃ Ｍｏの一種以上を
合金した鋼粉などの焼入性に優れる合金鋼粉を用いて、
黒鉛粉を混合後、゛成形、焼結、熱処理したりする方法
が用いられているが、これらの方法で製造された燃結機
械部品は、強度的に十分ではなく、その上靭性に劣ると
いった欠点を有していた。この傾向は、部材の強度が増
すはと顕著となり、高強度化すればするほど靭性低下を
来すのが°常であった。このよう＆ｃ，従来公知の鉄鋼
粉では、強度的に今一歩の感がする上、靭性的に劣るの
で、これらの点を改善することが粉末冶金関係者、中で
も鉄鋼粉製造メーカーに昧された諌題であった。Usually, in order to increase the strength of sintered machine parts, pure iron powder is mixed with copper powder, nickel powder, and graphite powder, formed, sintered, and heat treated as necessary, or Mn, Cr,
Using alloyed steel powder with excellent hardenability, such as copper powder alloyed with Mo, V /a [or one or more types, or steel powder alloyed with one or more of Ni, Cu #Mo,
After mixing graphite powder, ``molding, sintering, and heat treatment'' are used, but the sintered machine parts manufactured by these methods do not have sufficient strength and have poor toughness. It had drawbacks. This tendency becomes more noticeable as the strength of the member increases, and the higher the strength, the lower the toughness usually occurs. In this way, the conventionally known iron and steel powders feel like they are one step ahead in terms of strength and are inferior in toughness, so it has been unclear to those involved in powder metallurgy, especially the manufacturers of iron and steel powders, to improve these points. It was a taunt.
本発明はこのような当腋技術分野の要望に応え、かつ従
来の鉄鋼粉の欠点・問題点を克服して、焼結製品の強度
と靭性の改善・向上を同時に可能とする合金鋼粉を提供
するものであり、その骨子とするところは、（１）＝焼
入性向上に寄与し、がっ炭化物生成傾向の強い元素、す
なわち炭素との親和力の強い元素を合金することで、こ
の範噛に入る元素はＭｎ 、 Ｃｒ 、 Ｍｏ 、 Ｖ
ａ Ｗである。ただしＶ。The present invention meets the needs of the technical field, and provides an alloy steel powder that overcomes the drawbacks and problems of conventional iron and steel powders and simultaneously improves the strength and toughness of sintered products. The main points are (1) = alloying of elements that contribute to improved hardenability and have a strong tendency to form carbon carbides, that is, elements that have a strong affinity with carbon; The elements involved are Mn, Cr, Mo, and V.
aW. However, V.
ＷはＭｎ 、 Ｃｒ 、 Ｍｏに較べれば焼入性向上へ
の寄与の度合は幾分低いが本発明では特別に支障はない
。次Ｋ（２）としては上記（１）Ｋ加えてＰを合金する
ことであって、Ｐは炭素を反撥しかつ炭化物を生成しな
い元素である。すなわち、本発明の要旨はＭｎ１．３％
（以下総べてｌ−量％）以下、 Ｃｒ １３％以下、
Ｍｏダ。ｔ％以下、Ｖ／。θ％以下、Ｗコ、θ％以下の
うちから選ばれた１種または一株以上を含み、しかもＭ
ｎ ＋ Ｃｒ ＋ Ｍｏ ＋ Ｖ ＋ Ｗの合計が□、
６〜６゜３％の範囲内であって、かっｐ ｏ、ｏ＋ｚ〜
０．１！％ 、 ８１０．１０％以下、 ｃ ｏ、ｉｓ
％以下、ｏｏ、ｔ□％以下を含有する合金鋼粉である。Although W has a somewhat lower contribution to improving hardenability than Mn, Cr, and Mo, it poses no particular problem in the present invention. The next K(2) is to alloy P in addition to the above K in (1), where P is an element that repels carbon and does not form carbides. That is, the gist of the present invention is that Mn1.3%
(All below are l-amount%) or less, Cr 13% or less,
Mo da. t% or less, V/. Contains one or more strains selected from θ% or less, W co, θ% or less, and M
The sum of n + Cr + Mo + V + W is □,
Within the range of 6 to 6°3%,
0.1! %, 810.10% or less, co, is
% or less, oo, t□% or less.
本発明の骨子は前述のように、炭化物生成傾向の強い元
素とＰとを合金ｂｖ分とすることであるが、この他にも
ト記のようにＢｉｅ ｏ ｌ ｅの各含有量を一定限度
以下に抑制することが必要である。ただし、これらは本
発明鋼粉の性能を効果的に発揮させる側面的な要因であ
るが、本質的な事項ではない。As mentioned above, the gist of the present invention is to make the alloy bv of elements with a strong tendency to form carbides and P, but in addition to this, as described in It is necessary to suppress the following. However, although these are side factors for effectively demonstrating the performance of the steel powder of the present invention, they are not essential matters.
このようなＰを合金した鉄系金属粉末は、特開昭！３−
／４０り号公報および特開昭ｊ！ｒ−／ Ａ ／ ００
コ号公報に提案されているが、前者はＰ含有量が２．３
％以上のＦｅ −Ｐ系微細粉末を鉄鋼粉に混合したもの
である。また後者は、Ｐを０．０！ｒ〜０．３０％合金
合金純鉄粉に関するもので、とくにアトマイズ条件の変
更を通じて粉末粒子形状の不規則度を高め、加えて粉末
粒子表面にＰを析出させて、アトマイズ鉄粉の欠点とさ
れる成形性不良を改善したものである。この鉄粉のＭｎ
ｆは０．３３％以下に抑制されている。これら従来の鉄
鋼粉に対し、本発明の粉末冶金用の合金鋼粉では、焼入
性向上に寄与するＭｎ 、 Ｃｒ 、 Ｍｏ 、 Ｖ
、 Ｗといった元素を積極的に合金して、その上でＰを
合金し、強度と靭性の双方を向上させたものであって、
本質的に異なったものである。また特開昭ｊ＆−／ ４
７００１号の発明には、焼入性向上に寄与する元素が合
金されていないため、後述するような本発明鋼粉におけ
るＰの作用、すなわち焼結鋼の焼入、性向上と気孔の球
状化による強度および靭性双方の同時向上の作用がなく
、後述するように、寸法変化の挙動においても差異を生
じ−てくる。Such P-alloyed iron-based metal powder is available from JP-A-Sho! 3-
/40ri publication and JP-A-Shoj! r-/A/00
The former has a P content of 2.3.
% or more of Fe-P based fine powder is mixed with iron and steel powder. Also, in the latter case, P is 0.0! r ~ 0.30% alloy Pure iron powder is concerned, and in particular, by changing the atomization conditions, the irregularity of the powder particle shape is increased, and in addition, P is precipitated on the powder particle surface, which is considered to be a drawback of atomized iron powder. This improves the poor moldability. Mn of this iron powder
f is suppressed to 0.33% or less. In contrast to these conventional steel powders, the alloy steel powder for powder metallurgy of the present invention contains Mn, Cr, Mo, and V, which contribute to improving hardenability.
, W is actively alloyed with elements such as W, and then P is alloyed therewith to improve both strength and toughness.
They are essentially different. Also, Tokukai Shoj &-/4
In the invention of No. 7001, since elements contributing to improvement of hardenability are not alloyed, the effect of P in the steel powder of the present invention as described later, that is, hardening of sintered steel, improvement of hardenability, and spheroidization of pores. Therefore, there is no simultaneous improvement in both strength and toughness, and as will be described later, differences also occur in the behavior of dimensional changes.
次に本発明を靜細にＨ＆明する。Next, the present invention will be explained in detail.
前述したように、炭化物生成元素のＭｎ 、Ｃｒ 。As mentioned above, Mn and Cr are carbide-forming elements.
Ｍｏ 、 Ｖ 、 Ｗは、Ｃとの親和力が強く、炭化物
を生成し易い元素であるが、同時に焼入性向上にも寄与
する元素である。これらの元素を、ＭｎＪ、７％ 、
Ｃｒ ｔ、！ｒ ％ 、 Ｍｏ ’Ｉ’、１
％ 、Ｖ ／、０％ 、Ｗコ、０％をそれぞれ上限
として、これらの１種または一種以上を合金したのち、
さらに、Ｃに対する反撥作用の強いＰをｏ、ｏＩＩｓ〜
０．２ｊ％の範囲で合金した輛粉に黒鉛粉を混合し、圧
縮成形後、非酸化性雰囲気中で焼結すると、Ｐは粉末粒
子表面に濃縮、偏析し易くなる。この現象は、Ｃを介し
たＰとＣとの相互作用（反撥）、Ｃと炭化物生成元素と
の相互作用（引力）の箱果生じるもので、炭化物生成元
素を合金しなければ、その偏析度合が余り大きくならな
い。この事実は、本発明者らにより見出された第７の特
徴であって、本発明鋼粉に黒鉛粉を混合し、圧縮、成形
して得た圧粉体を非酸化性雰囲気中でＩＯ３０℃以上に
加熱して焼結すると、（通常の鉄鋼粉の焼結に゛は７１
００〜１３００℃の範囲が使用される。）粉末粒子の接
触界面に液相を生成し、第１図に示すように、ネック部
の曲ボ半径が次第に大きくなって、その結果、気孔が球
状化する。接触界面に液相を生成するのは、炭化物生成
元素の合金化を介して、粉末粒子表面に過剰ＫＰが偏析
するからであり、このようにして気孔部の切欠効果が弱
まり、焼結鋼の強度、靭性が共に向上する。一般に鉄鋼
材料（焼結鋼を含む）は、強度が向上すれば靭性が低下
するのが普通である。Mo, V, and W are elements that have a strong affinity with C and easily generate carbides, but at the same time they are elements that also contribute to improving hardenability. These elements are MnJ, 7%,
Cr t,! r%, Mo 'I', 1
%, V/, 0%, Wco, 0%, respectively, after alloying one or more of these,
Furthermore, P, which has a strong repulsive effect on C, is o, oIIs~
When graphite powder is mixed with graphite powder alloyed in a range of 0.2j%, compression molded, and then sintered in a non-oxidizing atmosphere, P tends to concentrate and segregate on the powder particle surface. This phenomenon occurs as a result of the interaction between P and C (repulsion) through C, and the interaction (attraction) between C and carbide-forming elements.If the carbide-forming elements are not alloyed, their degree of segregation will increase. does not become too large. This fact is the seventh feature discovered by the present inventors, and the green compact obtained by mixing the steel powder of the present invention with graphite powder, compressing and molding the powder has an IO30 When sintered by heating above ℃, (normal steel powder sintering temperature is 71
A range of 00 to 1300°C is used. ) A liquid phase is generated at the contact interface of the powder particles, and as shown in FIG. 1, the radius of curvature of the neck gradually increases, and as a result, the pores become spherical. The reason why a liquid phase is generated at the contact interface is that excess KP is segregated on the powder particle surface through alloying of carbide-forming elements, and in this way, the notch effect of the pores is weakened, and the sintered steel Strength and toughness both improve. In general, as strength increases in steel materials (including sintered steel), toughness typically decreases.
しかし、本発明鋼粉を使用した焼結鋼の場合には、上述
のよ５に気孔が球状化するため、強度も靭性も共に向上
することが、見出された第一の特徴であって、これが本
発明の主要な効果の一つである。However, in the case of sintered steel using the steel powder of the present invention, the first characteristic discovered is that both strength and toughness are improved due to the spheroidization of the pores as described above. , this is one of the main effects of the present invention.
なお、液相な生成する結果、焼結時の寸法変化（収縮）
率は比較的大きく、従って焼結による密度増加は、Ｐ含
有量の少ない本発明以外の銅粉に較べてかなり大きい。Additionally, as a result of liquid phase formation, dimensional changes (shrinkage) occur during sintering.
The ratio is relatively large, and therefore the density increase due to sintering is considerably greater than for other copper powders with low P content.
勿論、この密度増加を通じて強度、靭性が向上すること
も事実ではあるが、本発明鋼粉の場合、その向上割合が
常識の範囲を越えて大きく、比較検討した結果、明らか
に気孔の球状化によることが立証き′れた。本発明の他
の効果は、Ｐの合金化により焼入性が向上する点である
。Ｍｎ 、 Ｃｒ 、 Ｍｏ 、 Ｖ 、 Ｗのような
炭化物を生成すると同時に、鋼材の焼入性の向上に作用
する元素を合金した状態で、さらに、Ｐを合金すると焼
入性が一段と向上する新規事実を見出した。これが本発
明における第３の特徴である。このＰ合金化による焼入
性向上の様子は、第１図に示したＰ量と理想臨界焼入直
径の関係からも理解されるところである。この結果、本
発明鋼粉を使用した場合、気孔の球状化と焼入性向上の
双方から、焼結鋼の強度は、熱処理を通じて一段と向上
する。Of course, it is true that strength and toughness improve through this increase in density, but in the case of the steel powder of the present invention, the rate of improvement is greater than the range of common sense, and after a comparative study, it is clear that this is due to the spheroidization of the pores. This has been proven. Another effect of the present invention is that hardenability is improved by alloying P. A new fact that when alloyed with elements that improve the hardenability of steel materials, such as Mn, Cr, Mo, V, and W, and at the same time, alloyed with P, the hardenability is further improved. I found out. This is the third feature of the present invention. The improvement in hardenability due to P alloying can also be understood from the relationship between the amount of P and the ideal critical hardening diameter shown in FIG. As a result, when the steel powder of the present invention is used, the strength of the sintered steel is further improved through heat treatment due to both the spheroidization of pores and the improvement of hardenability.
このように、本発明鋼粉を提供することにより、焼結鋼
の強度、靭性は格段に向上し、高強度、高靭性焼結機械
部品用の原料鋼粉として、その要求に十分に応え得るこ
とができるようになった。As described above, by providing the steel powder of the present invention, the strength and toughness of sintered steel can be significantly improved, and the steel powder can fully meet the requirements as a raw material steel powder for high-strength, high-toughness sintered machine parts. Now I can do it.
次に１本発明鋼粉における各合金元素量の限定理由を説
明する。Ｍｎ 、Ｃｒ 、 Ｍｏ 、 Ｖ 、 Ｗの各
上限量コ、３％、６．Ｓ％、参、１％、／、０％、コ、
Ｏ％は、焼入性向上に寄与する限界から決定した。さら
にこれらの７種または一種以上を、上記上限量以下の範
囲で合金する場合、これらの合計量を０．６〜６．３％
の範囲にする必要がある。その理由は、合計量が下限値
の０．４％未満の場合、Ｐを本発明の範囲内で合金、共
存化させても十分な焼入性が確保されないから、焼結鋼
の高強度化を望むことが出来ない。また合計量が０．４
％未満の場合、Ｐによる液相焼結が進行し難く、気孔の
球状化が期待できない。このように、本発明鋼粉では炭
化物生成傾向が強く、かつ焼入性向上元素でもあるＭｎ
。Next, the reason for limiting the amount of each alloying element in the steel powder of the present invention will be explained. Each upper limit amount of Mn, Cr, Mo, V, and W is 3%, 6. S%, 1%, /, 0%, ko,
O% was determined from the limit that contributes to improving hardenability. Furthermore, when these seven or more types are alloyed in a range below the above upper limit amount, the total amount of these should be 0.6 to 6.3%.
It needs to be within the range. The reason for this is that if the total amount is less than the lower limit of 0.4%, sufficient hardenability cannot be ensured even if P is alloyed or coexisting within the scope of the present invention. I can't hope for it. Also, the total amount is 0.4
If it is less than %, liquid phase sintering due to P is difficult to proceed, and spheroidization of pores cannot be expected. In this way, the steel powder of the present invention contains Mn, which has a strong tendency to form carbides and is also an element that improves hardenability.
.
Ｏｒ 、 Ｍｏ 、 Ｖ ＃ ＷとＰとの同時合金化が
必要であり、しかもこれら炭化物生成元素の合計量には
、上述のように、本発明鋼粉の効果を発揮させるために
必要な下限量が存在するのである。一方、これらの合計
量の上限値は、銅粉の圧縮性、成形性の見地から決定し
たものであり、上限値の６．マ％を超えて合金した場合
には、圧縮性、成形性が低下して、強度、靭性の向上が
望めなくなる。次ＫＰは、気孔の球状化および焼入性向
上の観点から最低限Ｏ０θａＳ％は合金しなければなら
ない、しかし、その合金量が００１５％を超えて多くな
ると、炭化物形成元素の合計量の上限値限定理由と同様
、銅粉の圧縮性、成形性を阻害するので好ましくない。Or, Mo, V # Simultaneous alloying of W and P is required, and as mentioned above, the total amount of these carbide-forming elements has a lower limit amount necessary for exhibiting the effect of the steel powder of the present invention. exists. On the other hand, the upper limit of these total amounts was determined from the viewpoint of the compressibility and moldability of the copper powder, and the upper limit of 6. If the alloy exceeds M%, the compressibility and formability will decrease, making it impossible to expect improvements in strength and toughness. The next KP must be alloyed with a minimum of O0θaS% from the viewpoint of spheroidization of pores and improvement of hardenability. However, if the alloying amount exceeds 0015%, the upper limit of the total amount of carbide-forming elements Similar to the reason for limitation, this is not preferable because it impairs the compressibility and moldability of the copper powder.
また、この上限量を超えて多く合金した場合、鋼粉粒子
表面のＰ偏析蓋が極端に多くなり、その結果Ｆｅ３Ｐが
形成されて、この析出物のため焼結中の液相生成量が減
少し、密度増加が期待できなくなる。従・つて、気孔の
球状化も進み難く、析出した硬くて脆いＦｅ ｓＰ相と
相俟つ【、焼結鋼の強度、靭性も低下する。このような
本発明鋼粉を用いた焼結鋼が、Ｐの作用を有効利用して
いるのに対して、溶製法になる機械構造用鋼では、ＰＫ
よる鋼材の脆化を防ぐ意味から、Ｐ含有量の許容上限値
を０００３０％とし、脱燐を徹底的に行なって、極力Ｐ
含有量を低値に抑制する方法をとっており、この事実に
照しても本発明の独自性、卓越性が理解されるところで
ある。In addition, when alloying exceeds this upper limit, the P segregation cap on the surface of the steel powder particles becomes extremely large, resulting in the formation of Fe3P, and this precipitate reduces the amount of liquid phase produced during sintering. Therefore, no increase in density can be expected. Therefore, the spheroidization of the pores is difficult to proceed, and together with the precipitated hard and brittle FesP phase, the strength and toughness of the sintered steel are also reduced. While the sintered steel made using the steel powder of the present invention effectively utilizes the action of P, in the case of machine structural steel made by melting process, PK
In order to prevent the embrittlement of steel materials caused by oxidation, the allowable upper limit of P content is set at 00030%, and thorough dephosphorization is carried out to reduce P as much as possible.
A method is used to suppress the content to a low value, and even in light of this fact, the uniqueness and excellence of the present invention can be understood.
なお、本発明鋼粉では、８１ 、 Ｃ、Ｏの各元素量を
一定値以下に抑制することが肝要である。８１は、銅粉
中にあっては、酸素と結合して難還元性の酸化物を形成
し、これが銅粉の焼結性を阻害するばかりでなく、珪酸
塩系の長大介在物を形成して焼結鋼の機械的性質を劣化
させるので、その量を極力低く抑制しなければならず、
この点から本・。In addition, in the steel powder of the present invention, it is important to suppress the amounts of each element of 81, C, and O to below a certain value. In copper powder, 81 combines with oxygen to form a refractory oxide, which not only inhibits the sinterability of the copper powder but also forms long silicate-based inclusions. sintered steel and deteriorates the mechanical properties of the sintered steel, its amount must be kept as low as possible.
Books from this point.
発明では、０．１０％以下とした。酸素もまた有害元素
の一つであり、焼結鋼の十分な焼入性確保のため、およ
び、鋼粉粒子間の焼結性や鋼粉粒子と混合黒鉛粉との反
応性を良好に維持し、焼結鋼の機械的性質低下を防止す
るためなどの理由から低値に抑制せねばならず、その許
容上限量は０．７０％であることを確認した。また、本
発明のようＫ。In the invention, it is set to 0.10% or less. Oxygen is also a harmful element, and in order to ensure sufficient hardenability of sintered steel, maintain good sinterability between steel powder particles and reactivity between steel powder particles and mixed graphite powder. However, in order to prevent deterioration of the mechanical properties of sintered steel, it has to be suppressed to a low value, and it was confirmed that the upper limit of the allowable amount is 0.70%. Also, according to the present invention, K.
酸素量を０．７θ％以下に抑制した銅粉にあっては、黒
鉛粉を混合し圧縮成形後に、低露点の分解アンモニアガ
スや水素などの雰囲気中で／／！１０℃以上、好ましく
はｌコｏｏ −１ｙｏｏ″ｃ′に加熱、焼結すると、混
合した黒鉛粉により脱酸されて一層酸素量の低い焼結体
が得られるが、酸素量が０．１０％を超えて多い銅粉の
場合には、十分低酸素にすることができず、その上に、
黒鉛粉との反応性あるいは鋼粉粒子間の焼結性も阻害さ
れて、焼結鋼の機械的性質もまた低下する。このほか、
焼結鋼のＣ量調節が困難であったり、また多量の酸素に
より馳。Copper powder with oxygen content suppressed to 0.7θ% or less is mixed with graphite powder and compression molded in an atmosphere of low dew point decomposed ammonia gas, hydrogen, etc.//! When heated and sintered at 10° C. or higher, preferably 10° C. or higher, it is deoxidized by the mixed graphite powder and a sintered body with an even lower oxygen content is obtained, but the oxygen content is 0.10%. If the amount of copper powder exceeds
Reactivity with graphite powder or sinterability between steel powder particles is also inhibited, and the mechanical properties of the sintered steel are also reduced. other than this,
It is difficult to control the amount of carbon in sintered steel, and it also deteriorates due to large amounts of oxygen.
Ｃｒ 、 Ｖ等が酸化され、−これらの固溶量が減少す
る結果、焼入性も低下するなど整置が多くなる。従って
銅粉の酸素量は、必ず０．１０％以下に抑制しなければ
ならない。次にＣは、銅粉の圧縮性、成形性を良好に維
持す−る上から、０．７！％以下に抑制せねばならない
。とくに本発明のようｋＰを合金した銅粉の場合、第３
図に示すよ５に、鋼粉中のｐＨ，Ｃ量の増加により圧縮
性が阻害されるので、銅粉中のＣ量は極力低値に抑制す
ることが好ましい。Cr, V, etc. are oxidized, and the amount of these solid solutions decreases, resulting in decreased hardenability and increased alignment. Therefore, the amount of oxygen in the copper powder must be suppressed to 0.10% or less. Next, C is 0.7 to maintain good compressibility and moldability of copper powder! % or less. In particular, in the case of copper powder alloyed with kP as in the present invention, the third
As shown in Fig. 5, compressibility is inhibited by increases in pH and C content in the steel powder, so it is preferable to suppress the C content in the copper powder to as low a value as possible.
次に実施例により本発明を具体的に説明する。Next, the present invention will be specifically explained with reference to Examples.
第７表に実施例および比較例に用いた銅粉の化学組成を
示す。Table 7 shows the chemical composition of the copper powder used in Examples and Comparative Examples.
実施例／〜ダは、Ｍｎ −Ｃｒ −Ｍｏ系鋼粉にＰを本
発明の範囲内で合金したものであり、比較例１゜コは、
同じＭｎ −Ｃｒ −Ｍｏ系鋼粉でもＰ量が本発明の範
囲を外れて少ないか又は多いものである。Examples 1 to 2 are alloyed with Mn-Cr-Mo steel powder and P within the scope of the present invention, and Comparative Example 1 is as follows:
Even in the same Mn-Cr-Mo steel powder, the amount of P is too small or too large outside the scope of the present invention.
実施例３は、Ｃｒ −Ｍｏ −Ｖ系鋼粉ＫＰを本発明の
範囲内で合金したものであり、比較例Ｊは、同じＣｒ
−Ｍｏ −Ｖ系鋼粉でもＰ量が本発明の範囲を外れて低
いものである。これら第１表に示した銅粉を用いて、圧
粉密度Ａ −ｇ ｌ／ａｍ” 、焼結条件： ｔｔｒｏ
℃Ｘ ／ｈ、Ｈ，中焼結、ｃＩｔｏ、コ〜ｔｙ、ｔ％の
条件で焼結鋼を準備した。これら焼結鋼の機械的性質を
第２表に示す。Example 3 is an alloy of Cr-Mo-V steel powder KP within the scope of the present invention, and Comparative Example J is an alloy of Cr-Mo-V steel powder KP within the scope of the present invention.
-Mo -V steel powder also has a low P content outside the range of the present invention. Using these copper powders shown in Table 1, green powder density A-g l/am", sintering conditions: ttro
A sintered steel was prepared under the conditions of ℃X/h, H, medium sintering, cIto, co-ty, and t%. The mechanical properties of these sintered steels are shown in Table 2.
また、第１表中のＰ量が異なるＭｎ−Ｃｒ−Ｍｏ系鋼粉
６種類を用いて、前記圧粉密度および焼結条件で焼結し
た場合のＰ量と焼結密度およびＰ量と寸法変化率の関係
は第ダ図および第３図に示す通りである。このように本
発明鋼粉では、Ｐの合金化により寸法変化率が大きく変
化し、例えばｏ、ｏｉｔ％Ｐと０．１２％Ｐとでは、後
者が約０．４１％収縮量が大きくなる。この点もまた、
Ｐ量によって寸法変化率かはとんと変化しないとする特
開昭！ｔ！−／Ａ１００コ号と異なる点である。このよ
うな差異は、Ｍｎ 。In addition, using six types of Mn-Cr-Mo steel powders with different P amounts in Table 1, the P amount, sintered density, P amount and dimensions when sintered under the green powder density and sintering conditions described above. The relationship between the rates of change is as shown in Figures 1 and 3. As described above, in the steel powder of the present invention, the dimensional change rate changes greatly due to the alloying of P, and for example, between o, oit% P and 0.12% P, the latter has a larger shrinkage amount by about 0.41%. This point also
JP-A-Sho states that the dimensional change rate does not change significantly depending on the amount of P! T! This is different from the -/A100 issue. Such differences are due to Mn.
Ｃｒ 、 Ｍｏ 、 Ｖ 、 Ｗ等の炭化物形成元素を
合金するかしないかＫよって生じたものであり、この−
事からも本発明と特開昭１！？−１４１００１号とは本
質的に異なることがわかる。さて、ここで各実施例およ
び比較例について詳細に説明する。なお、銅粉の粒度は
、いずれも−６０メツシユであり、粒度分布は、各銅粉
とも６０〜１０メツシユア０〜１０ ％ 。It is produced depending on whether or not K is alloyed with carbide-forming elements such as Cr, Mo, V, and W, and this -
From the facts, this invention and Japanese Patent Application Publication No. 1! ? It can be seen that this is essentially different from No.-141001. Now, each example and comparative example will be described in detail. In addition, the particle size of each copper powder is -60 mesh, and the particle size distribution of each copper powder is 60 to 10 mesh and 0 to 10%.
ｔ０〜１００メツシュ／ｊ〜／ｊ％、 １０θ〜００メ
ツシュ／ｌＯ〜コＯ％、／！ｒＯ〜−〇〇メツシュ／コ
ｊ〜３！ｒ％。t0~100 mesh/j~/j%, 10θ~00 mesh/lO~koO%, /! rO~-〇〇Metshu/Koj~3! r%.
−〇〇〜コｊＯメツシュ／１０〜コ０％、コｊＯ〜３コ
Ｓメツシュ／Ｓ〜／ｊ％、 −３２３メツシュ／３〜コ
Ｏ％の範囲にあった。-〇〇~CojO mesh/10~Co0%, CojO~3CoS mesh/S~/j%, -323 mesh/3~CoO%.
工１上二
０、ｔ！ｒ Ｍｎ −／ Ｃｒ −０，コｊ Ｍｏ銅粉
（以下ベース銅粉という。）にＰを０．０ｊコ％合金し
た、本発明に属する銅粉に黒鉛粉を混合し、圧粉密度す
、ｔ ９／３ 、 ／／！０℃Ｘ／ｈ、Ｈ２中焼結して
、焼結鋼Ｃ量をＯｏ−％間隔で０．２〜０゜ｔ％の範囲
に変えた、これら焼結鋼の焼結のままおよび焼結後、焼
入−焼戻しだものの引張強さおよび衝撃値は、第２表に
示した通りであり、本発明以外の比較例／（０，０／４
％Ｐ）あるいは比較例コ（０，３０％Ｐ）と較べて強度
、靭性ともに優れていた。Engineering 1 upper 20, t! r Mn − / Cr −0, Coj Mo copper powder (hereinafter referred to as base copper powder) alloyed with 0.0j% P, which belongs to the present invention, is mixed with graphite powder, and the compacted powder density is t 9/3, //! The as-sintered and sintered steels were sintered at 0°C x/h in H2, and the sintered steel C amount was varied in the range of 0.2 to 0°t% in Oo-% intervals. The tensile strength and impact value of the quenched and tempered products are shown in Table 2.
%P) or Comparative Example (0.30%P), both strength and toughness were excellent.
！１愚Ｊ
実施例１と同様、ベース鋼粉ＫＰを０．０７ｔ％合金し
た本発明に属する銅粉を用いて、実施例Ｉと同様に黒鉛
粉を混合、成形、焼結し、実施例／と同様に機械的性質
を検討した。第２表から明らかな通り、引張強さ、衝撃
値ともに実施例１より一段と優れていた。! 1 UJ As in Example 1, copper powder belonging to the present invention alloyed with 0.07 t% of base steel powder KP was used, and graphite powder was mixed, molded, and sintered as in Example I. The mechanical properties were also examined in the same way. As is clear from Table 2, both tensile strength and impact value were much better than Example 1.
透」Ｉ江ヱ
ペース鋼粉へ、さらにＰを００７２％合金した本発明に
属する鋼粉に実施例／と同様に黒鉛粉を混合、成形、焼
結して、機械的性質を検討した。その結果、焼結鋼の強
度、靭性は、第２表に示した通り比較例／、コと較べて
格段に優れていた。例えばｏ、ｙ％Ｃ暁結鋼の焼入−焼
戻処理したものの引張強さは、１０／、Ｏｋｇ７ｍの値
を示し、比較例／。Graphite powder was mixed, molded, and sintered in the same manner as in Examples/Example/1 to the steel powder of the present invention alloyed with 0.72% P, and the mechanical properties were examined. As a result, as shown in Table 2, the strength and toughness of the sintered steel were significantly superior to those of Comparative Examples. For example, the tensile strength of o, y% C dawn steel subjected to quenching and tempering treatment shows a value of 10/, Okg7m, Comparative Example/.
−のそれらと較べてコＯ〜Ｓｔ ｋｌｌ／ｌａｘ も高
く、衝撃値もまた、比較例／、２よりｌ〜八へＫｋｇ・
ｍ／ＣｒｒＬ も高かった。Compared to those of -, the value of KO~St kll/lax is also higher, and the impact value is also Kkg.
m/CrrL was also high.
黒１１シ
ペース鋼粉にＰを０．−／％金合金た、本発明に属する
銅粉を用いて、実施例／〜Ｊと同様に焼結鋼の機械的性
質を検討した。結果は、第２表・杷示した通り、実施例
−と同等程度の強度、靭性であり、実施例Ｊよりは劣っ
ていたが比較例１．−よりかなり優れていた。Add 0.0 P to black 11-cypase steel powder. The mechanical properties of sintered steel were examined in the same manner as in Examples/~J using copper powder belonging to the present invention, which was a gold alloy with -/% gold alloy. As shown in Table 2, the results were comparable in strength and toughness to Example J, which was inferior to Example J, but Comparative Example 1. - was significantly better than
次にダＣｒ−０．コ！ｒＭｏ−０．／Ｖ鋼粉について、
同様にＰ合金化の効果を検討した。第１表で比較例３は
、Ｐｔが０．０−ｇ−％の本発明外の銅粉であり、実施
例Ｓは、本発明に属するものである。なお、■は、若干
の焼入性向上と組織の微細化を狙いとして合金したもの
である。Next, da Cr-0. Ko! rMo-0. /About V steel powder,
Similarly, the effect of P alloying was investigated. In Table 1, Comparative Example 3 is a copper powder other than the present invention containing 0.0-g-% Pt, and Example S belongs to the present invention. Note that (2) is an alloy with the aim of slightly improving hardenability and refining the structure.
実施例Ｓ
Ｑ Ｃｒ−０，−！ＭＯ−０，／Ｖ鋼粉＜ｐを０．７０
％合金合金本発明に属する銅粉に、黒鉛粉を混合して前
述のＭｎ−Ｃｒ−Ｍｏ系鋼粉と同一の条件で成形、焼結
して得たｏ、ｌＩ％Ｃ焼結鋼の引張強さ、衝撃値は、第
２表から明らかな通り、比較例３より格段に優れていた
。Example S Q Cr-0,-! MO-0, /V steel powder < p 0.70
% alloy alloy Tensile strength of o, lI%C sintered steel obtained by mixing graphite powder with copper powder belonging to the present invention, forming and sintering under the same conditions as the above-mentioned Mn-Cr-Mo steel powder. As is clear from Table 2, the strength and impact value were significantly superior to Comparative Example 3.
以上ｊつの実施例から明らかなように、本発明鋼粉では
、Ｍｎ 、 Ｃｒ 、Ｍｏ ｌ Ｖ 、 Ｗの元素に加
えてＰをｏ、ｏ４Ｉｒ〜θ、２５％の範囲で合金化する
ことにより、焼結鋼の強度、靭性が共に向上する。この
ような現象が生じるのは、前述した通り、合金したＰに
より焼結鋼の気孔が球状化され、かつ焼入性が向上する
からであり、全く新規な知見である。As is clear from the above examples, in the steel powder of the present invention, in addition to the elements Mn, Cr, MolV, and W, P is alloyed in the range of o, o4Ir to θ, 25%, so that Both the strength and toughness of sintered steel are improved. As mentioned above, this phenomenon occurs because the alloyed P makes the pores of the sintered steel spheroidal and improves the hardenability, which is a completely new finding.
なお、実施例／〜Ｓの各銅粉の粒子形状は、比較例／〜
３と較べて大差なく、とくに不規則度が増加したという
ことはなかった。In addition, the particle shape of each copper powder of Example/~S is that of Comparative Example/~
There was no significant difference compared to 3, and there was no particular increase in the degree of irregularity.
以−Ｆの１９明により、本発明の祥細を明らかにしたが
、本発明鋼粉の利点は、銅粉原価が余り高くならないで
、焼結−の強度、靭性を大幅に向上させ得る点にある。The details of the present invention have been clarified in Section F.19, and the advantage of the steel powder of the present invention is that it can significantly improve the strength and toughness of sintered steel without increasing the copper powder cost too much. It is in.
従って、本発明鋼粉が、今後高強度、高靭性を要求され
る焼結機械部品に適用され、その生産に大きく貢献する
ことが期待されるところである。Therefore, it is expected that the steel powder of the present invention will be applied to sintered machine parts that require high strength and high toughness in the future, and will greatly contribute to the production thereof.
ｙ１図は粉末粒子間の焼結ネック部での液相生成による
気孔の球状化を示す模式図、第一図はＰ箪と粉末鍛造鋼
の理想臨界焼入直径との関係を示す図、第３図は銅粉中
のＣ量とＰ量と圧縮性の関係を示す図、第ダ図は銅粉中
のＰ量と焼結密度との関係を示す図、第３図は銅粉中の
Ｐ量と焼結時の寸法変化率との関係を示す図である。
／・・・鋼粉粒子、コ・・・気孔、３・・・液相。
第２図
Ｐ量（％）
第８図
＠＃Ｃ量（％ジ
第４図
４！ＥＩ＃ ７’ｔ （％）
第５図
４Ａ 粉ｐｔ（％）Figure y1 is a schematic diagram showing the spheroidization of pores due to liquid phase formation at the sintering neck between powder particles, Figure 1 is a diagram showing the relationship between P-tube and the ideal critical quenching diameter of powder forged steel, Figure 3 is a diagram showing the relationship between the amount of C and the amount of P in copper powder and compressibility, Figure 3 is a diagram showing the relationship between the amount of P in copper powder and sintered density, and Figure 3 is a diagram showing the relationship between the amount of C and P in copper powder and compressibility. FIG. 3 is a diagram showing the relationship between the amount of P and the rate of dimensional change during sintering. /...Steel powder particles, K...pores, 3...liquid phase. Fig. 2 P amount (%) Fig. 8 @#C amount (%) Fig. 4 EI# 7't (%) Fig. 5 4A Powder pt (%)
Claims (1)
下、 Ｍｏ ４１．１％以下、 ｖ ｉ、０％以下、
Ｗ Ｊ、０％以下のうちから選ばれた〈種または一種以
上を含みｌ（ｎ 、 Ｃｒ 、 Ｍｏ 、 Ｖ 、 Ｗ
の合計が０．６＃〜１．３％で、かツｐ ｏ、ｏｏｓ
〜ｏ、ｘｚ％、 ｓｌｏ、ｉ。 °％以下、 Ｃｏ、ｉｚ％以下、ｏｏ、７０％以下を含
有する高強度、高靭性焼結機械部品用合金鋼粉。[Claims] t, by weight percentage, 3% or less, Or 4mk% or less, Mo 41.1% or less, v i, 0% or less,
W J, selected from 0% or less (n, Cr, Mo, V, W
The total of is 0.6#~1.3%, and
~o, xz%, slo, i. A high-strength, high-toughness alloy steel powder for use in sintered machine parts containing up to 70% Co, up to iz%, and up to 70% oo.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56186217A JPS5887252A (en) | 1981-11-20 | 1981-11-20 | Alloy steel powder for sintered machine parts with high strength and toughness |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56186217A JPS5887252A (en) | 1981-11-20 | 1981-11-20 | Alloy steel powder for sintered machine parts with high strength and toughness |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5887252A true JPS5887252A (en) | 1983-05-25 |
Family
ID=16184413
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56186217A Pending JPS5887252A (en) | 1981-11-20 | 1981-11-20 | Alloy steel powder for sintered machine parts with high strength and toughness |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5887252A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6077901A (en) * | 1983-10-04 | 1985-05-02 | Kawasaki Steel Corp | Alloy steel powder for powder metallurgy |
| WO1999050009A1 (en) * | 1998-03-26 | 1999-10-07 | Japan As Represented By Director General Of National Research Institute For Metals | High-strength metal solidified material and acid steel and manufacturing methods thereof |
-
1981
- 1981-11-20 JP JP56186217A patent/JPS5887252A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6077901A (en) * | 1983-10-04 | 1985-05-02 | Kawasaki Steel Corp | Alloy steel powder for powder metallurgy |
| JPS6365721B2 (en) * | 1983-10-04 | 1988-12-16 | Kawasaki Steel Co | |
| WO1999050009A1 (en) * | 1998-03-26 | 1999-10-07 | Japan As Represented By Director General Of National Research Institute For Metals | High-strength metal solidified material and acid steel and manufacturing methods thereof |
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