JP3226618B2 - Iron-based sintered alloy for valve seat - Google Patents

Iron-based sintered alloy for valve seat

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Publication number
JP3226618B2
JP3226618B2 JP23303892A JP23303892A JP3226618B2 JP 3226618 B2 JP3226618 B2 JP 3226618B2 JP 23303892 A JP23303892 A JP 23303892A JP 23303892 A JP23303892 A JP 23303892A JP 3226618 B2 JP3226618 B2 JP 3226618B2
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JP
Japan
Prior art keywords
valve seat
alloy
powder
particles
iron
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 - Fee Related
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JP23303892A
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Japanese (ja)
Other versions
JPH0657387A (en
Inventor
義孝 高橋
忠孝 金子
博司 岡島
直樹 本岡
博之 岩垣
Original Assignee
トヨタ自動車株式会社
住友電気工業株式会社
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Publication of JPH0657387A publication Critical patent/JPH0657387A/en
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Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【0001】[0001]
【産業上の利用分野】本発明は自動車内燃機関のバルブ
シート用焼結合金に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sintered alloy for a valve seat of an automobile internal combustion engine.
【0002】[0002]
【従来の技術】バルブシートは、内燃機関のシリンダー
ヘッドに組み込まれている部材であり、きのこ形のバル
ブのバルブフェースが着座することにより、混合ガスや
燃焼ガスをシールするものである。バルブは燃焼ガス中
で高速で上下運動してバルブシートに着座と離脱を繰り
返すので、バルブシートは耐熱性、耐食性および耐摩耗
性と併せて、相手材であるバルブを摩耗させない相手攻
撃性が要求される。
2. Description of the Related Art A valve seat is a member incorporated in a cylinder head of an internal combustion engine, and seals a mixed gas or a combustion gas when a valve face of a mushroom-shaped valve is seated. Since the valve moves up and down at high speed in the combustion gas and repeatedly sits on and separates from the valve seat, the valve seat must have heat resistance, corrosion resistance and abrasion resistance, as well as aggressiveness to the partner material that does not wear the valve. Is done.
【0003】従来のバルブシート材料としては、Fe−
C−Co−Ni基材料、Fe−C基材料に耐摩耗性の向
上を狙ってフェロモリブデン(Fe−Mo)、フェロク
ロム(Fe−Cr)等の金属間化合物またはFe−C−
Cr−Mo−V合金等を添加したものが使用されている
(特開昭56−154110号公報)。
[0003] Conventional valve seat materials include Fe-
Intermetallic compounds such as ferromolybdenum (Fe-Mo) and ferrochrome (Fe-Cr) or Fe-C- are used for C-Co-Ni-based materials and Fe-C-based materials in order to improve wear resistance.
A material to which a Cr-Mo-V alloy or the like is added has been used (JP-A-56-154110).
【0004】さらに、CrおよびMoを含有するFe−
C基地組織中に、Cr、Mo、V等からなる鉄系硬質粒
子を分散させ耐摩耗性と相手攻撃性を改善した焼結合金
(特開昭60−224762号公報)、Pb合金等を含
浸させたFe−C−Co−Ni系基地組織中にFeMo
およびFeWからなる硬質粒子を分散させた焼結合金
(特開昭62−202058号公報)が開示されてい
る。
Further, Fe— containing Cr and Mo
Impregnated with a sintered alloy (Japanese Unexamined Patent Publication No. Sho 60-224762), a Pb alloy, etc. in which iron-based hard particles composed of Cr, Mo, V, etc. are dispersed in a C base structure to improve abrasion resistance and aggressiveness to a partner. FeMo in the Fe-C-Co-Ni-based matrix
And a sintered alloy in which hard particles made of FeW are dispersed (Japanese Patent Application Laid-Open No. 62-202058).
【0005】また、特開昭60−258449号公報に
は、オーステナイト組織、パーライト組織、フェライト
組織の混合組織からなるFe−C−Co−Ni系基地組
織中に、Fe−Mo合金層からなる硬質粒子を均一に分
散し、該硬質粒子を基地組織中に拡散させて強固に結合
したバルブシート用鉄系焼結合金が開示されている。
Japanese Patent Application Laid-Open No. 60-258449 discloses a Fe-C-Co-Ni-based base structure comprising a mixed structure of an austenitic structure, a pearlite structure, and a ferrite structure, and a hard structure comprising an Fe-Mo alloy layer. There is disclosed an iron-based sintered alloy for a valve seat in which particles are uniformly dispersed, and the hard particles are diffused into a matrix and firmly bonded.
【0006】[0006]
【発明が解決しようとする課題】然るに、最近は自動車
エンジンにおいて、長寿命化、高出力、高回転化、排出
ガス浄化対策、あるいは燃費向上対策に対する改善要求
が一段と高まっている。このため、自動車エンジンにお
けるエンジンバルブ、バルブシートに対しては、従来に
も増して厳しい使用環境に耐えることが不可避となって
きており、耐熱性、耐摩耗性をより一層向上させると共
に、高温での耐食性を向上させる必要が生じてきてい
る。
In recent years, however, there has been a growing demand for improvement in automobile engines for longer life, higher output power, higher rotation speed, measures for purifying exhaust gas, or measures for improving fuel efficiency. For this reason, it has become unavoidable for engine valves and valve seats in automobile engines to withstand more severe use environments than ever before, and heat resistance and wear resistance are further improved, and at high temperatures. It has become necessary to improve the corrosion resistance of steel.
【0007】本発明は、最近の自動車エンジンの高出力
化、燃費の向上等に伴う従来のバルブシート用焼結合金
の高性能化の要請に対応すべく発明されたものであっ
て、耐熱性および耐摩耗性をより一層向上させることの
できるバルブシート用鉄基焼結合金を提供することを目
的とする。
SUMMARY OF THE INVENTION The present invention has been developed to meet the recent demand for higher performance of conventional sintered alloys for valve seats, which is accompanied by higher output of automobile engines and improved fuel efficiency. It is another object of the present invention to provide an iron-based sintered alloy for a valve seat that can further improve wear resistance.
【0008】[0008]
【課題を解決するための手段】発明者等は先ず基地組織
に分散させる硬質粒子の粒径に着目して研究を進めた。
従来一般に用いられている硬質粒子は、耐摩耗性と相手
攻撃性のバランスを考慮して、平均粒径を45μm以下
の微粉に制御する場合が多く見受けられる。この様な平
均粒径を持つ粉末は、通常の粉末製造法により製造する
と収率が低いため、バルブシートが高価格となる。
Means for Solving the Problems The inventors of the present invention have focused on the particle size of hard particles dispersed in a matrix, and have conducted research.
Hard particles generally used in the past are often controlled to have an average particle size of 45 μm or less in consideration of the balance between abrasion resistance and counterpart aggression. A powder having such an average particle diameter has a low yield when manufactured by a normal powder manufacturing method, and thus the valve seat becomes expensive.
【0009】このように、平均粒径が45μm以下の硬
質粒子が用いられる理由は、相手攻撃性が低減するため
である。これは、硬質粒子の粒径が大きくなるほど相手
バルブを摩耗させる傾向が強くなることから、これを防
止するため、やむなく高価な微粒子を使用している。そ
こで、発明者等は平均粒径が大きくても相手攻撃性の少
ない硬質粒子について研究を進めた。その結果、硬質粒
子内に一定割合の気孔を内在し、比重比が20〜80%
である硬質粒子は、粗大粒子を用いても相手攻撃性が少
なく、優れた耐摩耗性が発揮されることを新たに知見し
た。
The reason why hard particles having an average particle size of 45 μm or less are used is that the aggressiveness of the partner is reduced. This is because, as the particle size of the hard particles increases, the tendency to wear the mating valve increases, and in order to prevent this, expensive fine particles are unavoidably used. Therefore, the present inventors have conducted research on hard particles having a large average particle diameter and low aggressiveness to the other party. As a result, a certain percentage of pores are present in the hard particles, and the specific gravity ratio is 20 to 80%.
It has been newly discovered that the hard particles having a low aggressiveness even when coarse particles are used and exhibit excellent wear resistance.
【0010】発明者等は前記知見をもとに、基地組織に
Cr、Ni、Mn、Moを固溶させることにより基地組
織を強化し、耐熱性、耐食性および耐摩耗性を向上させ
ると共に、CaF2、MoS2、MnS等の固体潤滑材を
分散させて耐摩耗性と被削性を向上させて本発明を完成
したものである。
[0010] Based on the above findings, the inventors strengthen the base structure by dissolving Cr, Ni, Mn, and Mo in the base structure, improve the heat resistance, corrosion resistance, and wear resistance, and improve the CaF. 2 , a solid lubricant such as MoS 2 or MnS is dispersed to improve wear resistance and machinability, thereby completing the present invention.
【0011】本発明のバルブシート用鉄基焼結合金は、
重量比で、Cr、Ni、Mn、Mo、Vのうち1種また
は2種以上を合計で2〜10%と、Cを0.5〜2.0
%を含有し、残部がFeおよび不可避不純物からなる鉄
基合金素地中に、Cr;30〜50%、W;10〜20
%、Mo;5〜15%、Fe;5〜15%、C;0.5
〜3%および不可避不純物を含有し残部がCoからな
り、(実測密度/理論密度)で定義される比重比が0.
2〜0.8であり、かつ粒子径が20〜150μmのC
o基合金粒子15〜35%と、CaF2、MoS2、Mn
Sのうち1種または2種以上の固体潤滑材粒子0.3〜
2.0%とを分散させたことを要旨とする。
The iron-based sintered alloy for a valve seat according to the present invention comprises:
By weight ratio, one or more of Cr, Ni, Mn, Mo and V are 2 to 10% in total, and C is 0.5 to 2.0.
%; The balance being Cr: 30 to 50%, W: 10 to 20 in an iron-based alloy base material comprising Fe and unavoidable impurities.
%, Mo; 5 to 15%, Fe; 5 to 15%, C: 0.5
-3% and unavoidable impurities, the balance being Co, and a specific gravity ratio defined by (measured density / theoretical density) of 0.
C of 2 to 0.8 and a particle size of 20 to 150 μm
15 to 35% of o-based alloy particles, CaF 2 , MoS 2 , Mn
One or more solid lubricant particles of S
2.0% is dispersed.
【0012】素地としては、例えば重量比でCr;0.
5〜2%、Mo;0.1〜1.0%、Mn;0.5〜
1.5%、Ni;1〜3%、C;0.5〜3%と不可避
不純物を含む鉄基合金、または重量比でCr;1.0〜
5%、Mo;0.1〜0.5%、V;0.1〜1.0
%、Ni;1〜3%、C;0.5〜3%と不可避不純物
を含む鉄基合金が適してる。これら合金は素地の耐熱
性、耐腐食性および強度が向上し、Co基合金粒子と相
まってバルブシート材料として優れた耐摩耗性および耐
腐食性を発揮するからである。
The substrate may be, for example, Cr: 0.
5 to 2%, Mo; 0.1 to 1.0%, Mn; 0.5 to
1.5%, Ni; 1 to 3%, C: 0.5 to 3% and an iron-based alloy containing unavoidable impurities, or Cr: 1.0 to
5%, Mo; 0.1 to 0.5%, V: 0.1 to 1.0
%, Ni: 1 to 3%, C: 0.5 to 3%, and an iron-based alloy containing unavoidable impurities is suitable. This is because these alloys have improved heat resistance, corrosion resistance and strength of the base material, and exhibit excellent wear resistance and corrosion resistance as a valve seat material in combination with the Co-based alloy particles.
【0013】[0013]
【作用】基地組織を構成する鉄基合金はCを0.5〜
2.0%を含有し、Cr、Ni、Mn、Mo、Vのうち
1種または2種以上を合計で2〜10%固溶させたの
で、基地組織が強化され、耐熱性、耐食性および耐摩耗
性を向上することができた。
[Action] The iron-base alloy constituting the matrix has a C content of 0.5 to
2.0%, and one or two or more of Cr, Ni, Mn, Mo, and V were solid-dissolved in a total amount of 2 to 10%, so that the base structure was strengthened, and the heat resistance, corrosion resistance, and resistance to heat were increased. Abrasion was able to be improved.
【0014】また、硬質粒子はCr、W、Mo、Fe等
を含有するCo基合金であって、硬質粒子内に一定割合
の気孔を内在し、比重比が20〜80%であるので、硬
質粒子として機能する部位の割合が低下し、粗大粒子を
用いても実質的に微細粒子を用いたのと同様の作用を発
揮し、相手攻撃性が少なく、優れた耐摩耗性が発揮され
る。特に有鉛ガソリンを使用した場合に、Co基合金粉
末中に内在する気孔が、燃焼生成物である鉛化合物を滞
留させ、これが潤滑性を向上し耐摩耗性の向上に寄与す
る。
The hard particles are a Co-based alloy containing Cr, W, Mo, Fe, etc., and have a certain percentage of pores in the hard particles and a specific gravity ratio of 20 to 80%. The ratio of the portions that function as particles is reduced, and even when coarse particles are used, the same effect as when fine particles are used is exerted, the opposing aggression is reduced, and excellent wear resistance is exhibited. In particular, when leaded gasoline is used, pores existing in the Co-based alloy powder retain lead compounds as combustion products, which improve lubricity and contribute to improvement in wear resistance.
【0015】さらに、固体潤滑材として、CaF2、M
oS2、またはMnSを分散させることにより、被削性
を向上させることができ、その上限2.0%に規制する
ことにより、耐腐食性および耐酸化性を損なうことなく
被削性を著しく向上することができた。
Further, as a solid lubricant, CaF 2 , M
By dispersing oS 2 or MnS, the machinability can be improved, and by regulating the upper limit to 2.0%, the machinability is significantly improved without impairing the corrosion resistance and oxidation resistance. We were able to.
【0016】次に、本発明において成分組成、比重比、
粒径等を限定した理由について説明する。素地中のC
r、Ni、Mn、Mo、Vのうち1種または2種以上;
2〜10%素地中のCr、Ni、Mn、MoおよびV
は、ベースである鉄に固溶してこれを強化する目的によ
り添加されるものである。これら元素が2%未満では強
化の効果が小さく目的を達成できず、10%を越えて含
有させてもより一層の改善効果は期待できず、また経済
的な理由も考慮して、その含有量を2〜10%に限定し
た。
Next, in the present invention, the component composition, specific gravity ratio,
The reason for limiting the particle size and the like will be described. C in the base
one or more of r, Ni, Mn, Mo, V;
Cr, Ni, Mn, Mo and V in 2-10% base
Is added for the purpose of forming a solid solution in iron as a base and strengthening it. If the content of these elements is less than 2%, the effect of strengthening is small and the object cannot be achieved. Even if the content exceeds 10%, no further improvement effect can be expected, and the content is considered in consideration of economic reasons. Was limited to 2-10%.
【0017】素地中のC;0.5〜2.0% 素地中の炭素は、ベースである鉄に固溶し、耐摩耗性を
付与しこれを強化する目的により添加されるものであ
り、0.5%未満の含有量では前記効果が充分に得られ
ず、2.0%を越えて含有させると炭化物が過剰に生成
し、素地の脆化を来すおそれがあり、また相手材を過度
に摩耗する可能性があるからその含有量を0.5〜2.
0%に限定した。
C in the base material: 0.5 to 2.0% Carbon in the base material is added for the purpose of forming a solid solution in iron as a base, imparting abrasion resistance and strengthening it. If the content is less than 0.5%, the above effects cannot be sufficiently obtained. If the content exceeds 2.0%, carbides are excessively generated, which may cause brittleness of the base material. Since there is a possibility of excessive wear, the content is set to 0.5 to 2.
Limited to 0%.
【0018】Co基合金粒子;15〜35% Co基合金粒子は、素地中に分散して耐摩耗性の向上を
図るものである。その分散量が15%未満では耐摩耗性
の向上が不十分であり、35%を越えると、添加の割合
に耐摩耗性の向上が見られず、相手攻撃性が増大し、バ
ルブ材を摩耗させるようになるため好ましくないため、
その分散量を15〜35%に限定した。
Co-based alloy particles: 15 to 35% Co-based alloy particles are dispersed in a base material to improve wear resistance. If the amount of dispersion is less than 15%, the improvement of the wear resistance is insufficient, and if it exceeds 35%, the improvement of the wear resistance is not seen in the proportion of addition, the aggressiveness of the partner increases, and the valve material is worn. Because it is not preferable because it will cause
The amount of dispersion was limited to 15-35%.
【0019】なお、Co基合金粉末の比重比(実測密度
/理論密度)は、実測密度については市販の比重瓶にて
測定し、理論密度は当該合金粉末を溶解後、鋳型に注湯
し、冷却し、冷却した材料の密度を測定して求められ
る。Co基合金粉末の比重比を0.2〜0.8に限定し
たのは、0.2未満では粒子自体の強度が低下し、成形
時の圧力により押し潰される可能性があるため好ましく
ないからであり、0.8を越えると内在する気孔が減少
し、相手攻撃性が増大するからである。
The specific gravity ratio (actual density / theoretical density) of the Co-based alloy powder was measured with a commercially available pycnometer, and the theoretical density was poured into a mold after dissolving the alloy powder. Determined by measuring the density of the cooled and cooled material. The specific gravity ratio of the Co-based alloy powder is limited to 0.2 to 0.8. If the specific gravity ratio is less than 0.2, the strength of the particles themselves is reduced, and the particles may be crushed by pressure during molding. When the ratio exceeds 0.8, the number of internal pores decreases and the aggressiveness of the opponent increases.
【0020】また、Co基合金粉末粒子の粒径を20〜
150μmに限定したのは、粒径が20μm未満である
と、充分な耐摩耗性を発揮することができずまた粉砕の
ためにコスト高となるからであり、150μmを越える
と相手攻撃性が増大するからである。
The Co-based alloy powder particles have a particle size of 20 to
The reason why the particle size is limited to 150 μm is that if the particle size is less than 20 μm, sufficient abrasion resistance cannot be exhibited, and the cost for pulverization becomes high. Because you do.
【0021】CaF2、MoS2、MnSのうち1種また
は2種以上の固体潤滑材粒子;0.3〜2.0% 固体潤滑材は、主として被削性向上を目的に添加するも
のであり、0.3%未満では被削性改善の効果が小さ
く、2.0%を越えても添加の割に効果向上が少なく、
強度低下の可能性があるため、0.3〜2.0%に限定
した。
Solid lubricant particles of one or more of CaF 2 , MoS 2 and MnS; 0.3 to 2.0% solid lubricant is added mainly for the purpose of improving machinability. If less than 0.3%, the effect of improving machinability is small, and if it exceeds 2.0%, the effect does not improve much for the addition.
Since the strength may be reduced, the content is limited to 0.3 to 2.0%.
【0022】[0022]
【実施例】本発明を具体的な実施例により説明し本発明
の効果を明らかにする。原料粉末として粉末粒度150
μm以下のCr1.1%、Mn0.8%、Mo0.3%
と不可避不純物を含む鉄基合金粉末(以下粉末Aと称す
る。)、Cr3.1%、V0.3%、Mo0.3%と不
可避不純物を含む鉄基合金粉末(以下粉末Bと称す
る。)、粉末粒度が45〜150μm(平均粒径が90
μm)であり比重比が0.4〜0.8のCr38%、W
14%、Mo11%、Fe11%、C2.4%と不可避
不純物を含むCo基水噴霧合金粉末(以下粉末Cと称す
る。)、粉末粒度が10〜45μm(平均粒径が30μ
m)であるCr39%、W15%、Mo11%、Fe1
0%、C2.6%と不可避不純物を含み比重比0.98
以上のCo基合金粉末(以下粉末Dと称する。)粉末粒
度が75μm以下のCaF2粉末、、粉末粒度が45μ
m以下のNi粉末、MoS2粉末、MnS粉末、天然黒
鉛粉末およびステアリン酸亜鉛粉末を準備した。
EXAMPLES The present invention will be described with reference to specific examples to clarify the effects of the present invention. Powder particle size 150 as raw material powder
Cr 1.1%, Mn 0.8%, Mo 0.3% of μm or less
And an iron-based alloy powder containing unavoidable impurities (hereinafter referred to as powder A), an iron-based alloy powder containing unavoidable impurities such as Cr 3.1%, V0.3%, and Mo0.3% (hereinafter referred to as powder B). Powder particle size is 45 to 150 μm (average particle size is 90
μm) and a specific gravity ratio of 0.4% to 0.8% of Cr 38%, W
Co-based water spray alloy powder containing 14%, Mo 11%, Fe 11%, C2.4% and unavoidable impurities (hereinafter referred to as powder C), powder particle size 10 to 45 μm (average particle size 30 μm)
m) Cr39%, W15%, Mo11%, Fe1
0%, C2.6%, including unavoidable impurities, specific gravity ratio 0.98
The above-mentioned Co-based alloy powder (hereinafter referred to as powder D) is a CaF 2 powder having a powder particle size of 75 μm or less, and a powder particle size of 45 μm.
m or less Ni powder, MoS 2 powder, MnS powder, natural graphite powder and zinc stearate powder were prepared.
【0023】これら原料粉末を表1に示す組成になるよ
うに秤量混合後、ステアリン酸亜鉛粉末1.0%を添加
し、V型混合装置により混粉を行なった。なお、表1に
おいて、比較材1および2は比重比が0.98以上のC
o基合金粉末を用いた比較例、比較材3は黒鉛添加量が
本発明の特許請求の範囲より少ない比較例、比較材4は
黒鉛添加量が本発明の特許請求の範囲より多い比較例で
ある。次に、450〜800MPaの範囲の成形圧力に
て、試験片形状の圧粉体を成形し、還元性雰囲気にて1
323〜1473Kの温度範囲にて1200〜7200
秒間保持し焼結を行なった。
These raw material powders were weighed and mixed so as to have the composition shown in Table 1, and then 1.0% of zinc stearate powder was added, followed by mixing with a V-type mixing device. In Table 1, the comparative materials 1 and 2 have a specific gravity ratio of 0.98 or more.
Comparative example using o-based alloy powder, Comparative material 3 is a comparative example in which the added amount of graphite is smaller than the claimed range of the present invention, and Comparative material 4 is a comparative example in which the added amount of graphite is larger than the claimed range of the present invention. is there. Next, at a molding pressure in the range of 450 to 800 MPa, a green compact in the form of a test piece is molded, and a green compact is formed in a reducing atmosphere.
1200 to 7200 in the temperature range of 323 to 1473K
Holding for 2 seconds, sintering was performed.
【0024】[0024]
【表1】 [Table 1]
【0025】続いて、不活性雰囲気にて、1173〜1
423Kの温度範囲に焼結体を保持後、プレス機にて4
50〜1400MPaの圧縮を行なった。その後圧縮体
を還元性雰囲気中にて1323〜1473Kの温度範囲
にて再焼結を行なった。なお、得られた焼結体のマトリ
ックスの組成および硬質粒子の含有量は表2に示す通り
であった。
Subsequently, in an inert atmosphere, 1173-1
After holding the sintered body in the temperature range of 423K,
Compression of 50 to 1400 MPa was performed. Thereafter, the compact was re-sintered in a reducing atmosphere in a temperature range of 1323 to 1473K. The composition of the matrix and the content of the hard particles of the obtained sintered body were as shown in Table 2.
【0026】[0026]
【表2】 [Table 2]
【0027】得られた各実施例および比較材について、
摩耗試験および耐久試験を行い、各材料の耐摩耗性並び
に相手攻撃性について調査し、バルブシートとしての適
合性を調査した。
For each of the obtained examples and comparative materials,
A wear test and a durability test were performed, and the wear resistance and aggressiveness of each material were investigated, and the suitability as a valve seat was investigated.
【0028】耐摩耗性試験は、各実施例および比較材を
バルブシート状に加工し、実機に模したバルブ、バルブ
シート試験機を用いて行った。この試験装置は、プロパ
ンガスの燃焼によってバルブとバルブシートを加熱し、
カムの駆動によってバルブを開閉する機構により、バル
ブとバルブシートの叩き摩耗状況を再現するものであ
る。試験は、バルブ材質をSUE50とし、バルブの温
度を1073K、バルブシートの温度を713Kに保つ
よう制御し、バルブの開閉数2200rpmにて運転時
間36Ksの条件で行い、バルブシート摩耗量を測定し
た。得られた結果は図1に示した。
The abrasion resistance test was performed by processing each of the examples and comparative materials into a valve seat shape, and using a valve and a valve seat testing machine simulating an actual machine. This test device heats the valve and valve seat by the combustion of propane gas,
The mechanism that opens and closes the valve by driving the cam reproduces the beating wear of the valve and the valve seat. The test was performed under the conditions that the valve material was SUE50, the temperature of the valve was maintained at 1073K, the temperature of the valve seat was maintained at 713K, the valve was opened and closed at 2200 rpm, and the operating time was 36Ks, and the amount of valve seat wear was measured. The results obtained are shown in FIG.
【0029】耐久試験は、公称2000ccエンジンを
用い、全負荷状態5650rpm×540Ks、使用燃
料;有鉛ガソリンにて実施し、タペットクリアランスの
変化を測定した。バルブはSUE50を用いた。得られ
た結果は図2に示した。
The endurance test was carried out using a nominally 2000 cc engine under a full load condition of 5650 rpm × 540 Ks, using fuel: leaded gasoline, and the change in tappet clearance was measured. The valve used was SUE50. The results obtained are shown in FIG.
【0030】図1の耐摩耗試験のバルブシート摩耗量に
示したように、比較材1および比較材2は、Co基合金
粉末に従来一般的に用いられている比重比が0.98以
上の合金粉末を用いたので、Co基合金粉末の組成が実
施例使用のCo基合金粉末とほぼ同一なのにもかかわら
ず、摩耗量が80μm前後で実施例の2倍以上と大き
く、また相手バルブの摩耗量が30〜38μmと大きく
なっている。
As shown in the wear amount of the valve seat in the abrasion resistance test of FIG. 1, the comparative materials 1 and 2 have a specific gravity ratio of 0.98 or more conventionally used for Co-based alloy powder. Since the alloy powder was used, despite the fact that the composition of the Co-based alloy powder was almost the same as that of the Co-based alloy powder used in the example, the wear amount was about 80 μm, which was twice or more that of the example, and the wear of the mating valve was large. The amount is as large as 30 to 38 μm.
【0031】また、比較材3は黒鉛添加量が本発明の特
許請求の範囲より少なかったので、マトリックス強化が
不充分で、バルブシートの摩耗量が40μm以上と増大
している。比較材4は黒鉛添加量が本発明の特許請求の
範囲より多かったため、マトリックス中に炭化物が過剰
に生成され、その結果相手バルブの摩耗量が40μm以
上となり、相手攻撃性が増加している。
Further, since the amount of graphite added to the comparative material 3 was smaller than the scope of the present invention, the matrix reinforcement was insufficient, and the wear amount of the valve seat was increased to 40 μm or more. Since the amount of graphite added to the comparative material 4 was larger than the scope of the claims of the present invention, an excessive amount of carbide was generated in the matrix, and as a result, the wear amount of the mating valve became 40 μm or more, and the mating aggressiveness increased.
【0032】これに対して本発明の実施例1〜8はバル
ブシート摩耗量が22〜35μmであり、バルブシート
の耐摩耗性が優れると共に、相手材であるバルブの摩耗
量も10〜21μmであって、相手攻撃性が少ないこと
が判明し、本発明の効果を確認することができた。
On the other hand, in Examples 1 to 8 of the present invention, the abrasion amount of the valve seat is 22 to 35 μm, the abrasion resistance of the valve seat is excellent, and the abrasion amount of the valve as the mating material is 10 to 21 μm. Thus, it was found that the opponent's aggressiveness was low, and the effect of the present invention could be confirmed.
【0033】図2の耐久試験のおける結果が示すよう
に、比較材1のタペットクリアランス変化量は0.25
mmであったのに対し、本発明の実施例1のタペットク
リアランス変化量は0.06mmであって、比較例の約
4分の1になっており、本発明の実施例は有鉛ガソリン
を使用しての高温での耐久試験においても、優れた耐熱
性、耐摩耗性および耐腐食性を発揮し、しかも相手攻撃
性の少ないことが確認された。このように実施例の優位
性が有鉛ガソリン使用エンジンにおいて顕著に表れる原
因としては、Co基合金粉末中に内在する気孔が、燃焼
生成物である鉛化合物を滞留させ、これが潤滑性を向上
し耐摩耗性の向上に寄与するものと考えられる。
As shown in the results of the durability test in FIG. 2, the change in tappet clearance of Comparative Material 1 was 0.25.
mm, the change in tappet clearance in Example 1 of the present invention was 0.06 mm, which is about one-fourth of that in the comparative example. In a durability test at a high temperature during use, it was confirmed that the material exhibited excellent heat resistance, abrasion resistance, and corrosion resistance, and had low aggressiveness to a partner. As described above, the superiority of the embodiment is remarkably exhibited in the engine using leaded gasoline. The pores existing in the Co-based alloy powder cause the lead compound, which is a combustion product, to stay, which improves lubricity. It is considered that this contributes to improvement of wear resistance.
【0034】図3は実施例2のバルブシートの粒子構造
を表す顕微鏡写真(倍率400倍)であり、図4は図3
の顕微鏡写真のCo基合金粒子の模写図である。図3お
よび図4において黒色部がCo基合金粒子に内在する気
孔を示すものである。
FIG. 3 is a micrograph (400-fold magnification) showing the particle structure of the valve seat of Example 2, and FIG.
FIG. 4 is a schematic view of Co-based alloy particles in the micrograph of FIG. In FIGS. 3 and 4, black portions indicate pores existing in the Co-based alloy particles.
【0035】[0035]
【発明の効果】本発明のバルブシート用鉄基焼結合金は
以上説明したように、基地組織を構成する鉄基合金はC
を0.5〜2.0%を含有し、Cr、Ni、Mn、M
o、Vのうち1種または2種以上を2〜10%固溶させ
たので、基地組織が強化され、耐熱性、耐食性および耐
摩耗性を向上することができた。また、硬質粒子はC
r;30〜50%、W;10〜20%、Mo;5〜15
%、Fe;5〜15%、C;0.5〜3%を含有するC
o基合金であって、硬質粒子内に一定割合の気孔を内在
し、比重比が20〜80%であるので、硬質粒子として
機能する部位の割合が低下し、粗大粒子を用いても実質
的に微細粒子を用いたのと同様の作用を発揮し、相手攻
撃性が少なく、優れた耐摩耗性が発揮する。特に有鉛ガ
ソリンを使用した場合に、Co基合金粉末中に内在する
気孔が、燃焼生成物である鉛化合物を滞留させ、これが
潤滑性を向上し耐摩耗性の向上に寄与する。さらに、固
体潤滑材として、CaF2、MoS2、またはMnSを分
散させることにより、耐焼付性および被削性を向上させ
ることができ、その上限を2.0%に規制することによ
り、耐腐食性および耐酸化性を損なうことなく被削性を
著しく向上することができた。
As described above, the iron-based sintered alloy for a valve seat according to the present invention is composed of C
From 0.5 to 2.0%, and Cr, Ni, Mn, M
Since one or two or more of o and V were solid-dissolved in 2 to 10%, the matrix structure was strengthened, and the heat resistance, corrosion resistance and wear resistance were able to be improved. The hard particles are C
r: 30 to 50%, W: 10 to 20%, Mo: 5 to 15
%, Fe; 5 to 15%, C; C containing 0.5 to 3%
An o-based alloy, in which a fixed percentage of pores are present in the hard particles and the specific gravity ratio is 20 to 80%, the ratio of the portions functioning as the hard particles is reduced, and even if coarse particles are used, The same action as when fine particles are used is exhibited, the aggressiveness to the opponent is small, and excellent wear resistance is exhibited. In particular, when leaded gasoline is used, pores existing in the Co-based alloy powder retain lead compounds as combustion products, which improve lubricity and contribute to improvement in wear resistance. Further, by dispersing CaF 2 , MoS 2 , or MnS as a solid lubricant, seizure resistance and machinability can be improved, and by limiting the upper limit to 2.0%, corrosion resistance can be improved. The machinability was significantly improved without impairing the properties and oxidation resistance.
【図面の簡単な説明】[Brief description of the drawings]
【図1】耐摩耗試験におけるバルブシートおよびバルブ
の摩耗量を示す図である。
FIG. 1 is a view showing a wear amount of a valve seat and a valve in a wear resistance test.
【図2】実機耐久試験におけるタペットクリアランス変
化量を示す図である。
FIG. 2 is a view showing a tappet clearance change amount in an actual machine durability test.
【図3】本発明の実施例の焼結合金の粒子構造を表す顕
微鏡写真である。
FIG. 3 is a micrograph showing a particle structure of a sintered alloy according to an example of the present invention.
【図4】図3の顕微鏡写真のCo基合金粒子の模写図で
ある。
FIG. 4 is a schematic view of Co-based alloy particles in the micrograph of FIG.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 岡島 博司 愛知県豊田市トヨタ町1番地 トヨタ自 動車株式会社内 (72)発明者 本岡 直樹 兵庫県伊丹市昆陽北1−1−1 住友電 気工業株式会社伊丹製作所内 (72)発明者 岩垣 博之 兵庫県伊丹市昆陽北1−1−1 住友電 気工業株式会社伊丹製作所内 (56)参考文献 特開 昭62−96662(JP,A) 特開 昭62−96660(JP,A) 特開 平2−182868(JP,A) 特開 平2−111848(JP,A) (58)調査した分野(Int.Cl.7,DB名) C22C 38/00 304 C22C 33/02 F01L 3/02 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Okajima 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Automobile Co., Ltd. (72) Inventor Naoki Motooka 1-1-1 Kunyokita, Itami City, Hyogo Sumitomo Electric Industries, Ltd. In Itami Works, Ltd. (72) Inventor Hiroyuki Iwaki 1-1-1, Koyokita, Itami-shi, Hyogo Sumitomo Electric Industries, Ltd. Itami Works, Ltd. (56) References JP-A-62-96662 (JP, A) JP-A 62-96660 (JP, A) JP-A-2-182868 (JP, A) JP-A-2-111848 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) C22C 38 / 00 304 C22C 33/02 F01L 3/02

Claims (1)

    (57)【特許請求の範囲】(57) [Claims]
  1. 【請求項1】 重量比で、Cr、Ni、Mn、Mo、V
    のうち1種または2種以上を合計で2〜10%と、Cを
    0.5〜2.0%を含有し、残部がFeおよび不可避不
    純物からなる鉄基合金素地中に、Cr;30〜50%、
    W;10〜20%、Mo;5〜15%、Fe;5〜15
    %、C;0.5〜3%および不可避不純物を含有し残部
    がCoからなり、(実測密度/理論密度)で定義される
    比重比が0.2〜0.8であり、かつ粒子径が20〜1
    50μmのCo基合金粒子15〜35%と、CaF2
    MoS2、MnSのうち1種または2種以上の固体潤滑
    材粒子0.3〜2.0%とを分散させたことを特徴とす
    るバルブシート用鉄基焼結合金。
    1. Cr, Ni, Mn, Mo, V in weight ratio
    One or two or more of them, a total of 2 to 10%, a content of C of 0.5 to 2.0%, and a balance of Cr; 50%,
    W; 10 to 20%, Mo; 5 to 15%, Fe; 5 to 15
    %, C; 0.5 to 3%, the balance containing Co and the unavoidable impurities, the specific gravity ratio defined by (measured density / theoretical density) is 0.2 to 0.8, and the particle size is 20-1
    15-35% of 50 μm Co-based alloy particles, CaF 2 ,
    MoS 2, 1 or more kinds of iron-based sintered alloy valve seat, characterized in that the solid lubricant particles 0.3 to 2.0% were dispersed among the MnS.
JP23303892A 1992-08-07 1992-08-07 Iron-based sintered alloy for valve seat Expired - Fee Related JP3226618B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP23303892A JP3226618B2 (en) 1992-08-07 1992-08-07 Iron-based sintered alloy for valve seat

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP23303892A JP3226618B2 (en) 1992-08-07 1992-08-07 Iron-based sintered alloy for valve seat

Publications (2)

Publication Number Publication Date
JPH0657387A JPH0657387A (en) 1994-03-01
JP3226618B2 true JP3226618B2 (en) 2001-11-05

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ID=16948835

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Country Link
JP (1) JP3226618B2 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08134607A (en) * 1994-11-09 1996-05-28 Sumitomo Electric Ind Ltd Wear resistant ferrous sintered alloy for valve seat
JP3447031B2 (en) * 1996-01-19 2003-09-16 日立粉末冶金株式会社 Wear resistant sintered alloy and method for producing the same
JP3447030B2 (en) * 1996-01-19 2003-09-16 日立粉末冶金株式会社 Wear resistant sintered alloy and method for producing the same
JP5649830B2 (en) * 2010-02-23 2015-01-07 株式会社リケン Valve seat

Also Published As

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