JPH0559981B2

JPH0559981B2 -

Info

Publication number: JPH0559981B2
Application number: JP4562986A
Authority: JP
Inventors: Yukio Kadota; Akira Manabe
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 1985-06-10
Filing date: 1986-03-03
Publication date: 1993-09-01
Also published as: JPS6296660A

Description

[Detailed description of the invention]

〔産業上の利用分野〕本発明は内燃機関のバルブシート用焼結合金に
係わり、より詳しくは合金自身の耐摩耗性を高め
るとともに、相手バルブに対する攻撃性を弱めた
鉄系焼結合金に関する。〔従来の技術〕最近、自動車用内燃機関は高出力、高回転化、
低燃費化が計られ、また排気ガス対策が施される
傾向にある。このため、バルブやバルブシート部
品は従来以上に厳しい条件にさらされるようにな
つてきている。このバルブシートには高温での耐摩耗性を高め
るため、Cr、Ni、Co、Mo等の合金元素を添加
した鉄系焼結合金が多用されつつある。〔発明が解決しようとする問題点〕ところで、バルブシートは、自身の耐摩耗性を
向上させるとともに相手バルブへの攻撃性の低減
が求められており、バルブシートの材質の選択
は、相手バルブとの相関において決定されるべき
もので、この選択を誤るとバルブ自身の耐摩耗性
を弱めるばかりか、相手部材に対する攻撃性を増
して、バルブ機構全体に思わしくない影響を与え
ることになる。そのため従来のような、例えばた
だ単にフエロモリブデン等の金属間化合物又は複
合炭化物を添加して極度に耐摩耗性を高めたバル
ブシートをそのまま使用すると、エンジンバルブ
の摩耗を増大させる結果となる。本発明は通常の、耐摩耗性が特に高められてい
ない汎用エンジンバルブ（例えばJIS NFC751
製）を相手にした場合にも相手材を摩耗すること
なく、又は自身の摩耗を著しく増大させることの
ないようにしようとするものである。〔問題を解決するための手段〕本発明のバルブシート用鉄系焼結合金は、重量
比で、クロム（Cr）、モリブデン（Mo）、バナジ
ウム（Ｖ）、及びマンガン（Mn）からなる群か
ら選ばれる元素１種又は２種以上を１〜20％、炭
素（Ｃ）0.5〜２％、所望により（Ni）１〜10％
及び不可避不純物を含む鉄基合金を基地とし、ク
ロム（Cr）10〜70％、タングステン（Ｗ）５〜
20％、モリブデン（Mo）５〜20％、炭素（Ｃ）
0.5〜３％、鉄（Fe）20％以下及び残部コバルト
（Co）からなる合金粒子５〜25％を前記基地中に
均一に分散させたことを特徴とする。また、本発明は前記焼結合金に鉛（Pb）１〜
20％を溶浸したことを特徴とする。なお、本発明において％は特記しないかぎり重
量％を示す。本発明で用いる各成分元素の限定理由について
説明する。まず、硬質粒子として加える合金粒子の各成分
元素について説明する。合金粒子中のCr（クロム）はＣ（炭素）と化合
して炭化物を形成するとともに一部がCoと合金
を形成し合金粒子の硬さを向上させる効果を有し
ているが、Crが10％未満では上記の効果が不十
分であり、70％を超えるとCrの拡散が周囲の基
地へ進み過ぎ、合金粒子の内部及び周縁に空隙を
生じ、合金粒子がもろくなる。そのためCrは10
〜70％と限定した。しかしながら、40〜70％がさ
らに好ましい。Ｗ（タングステン）は、Ｃと化合してMC型の
硬質炭化物とCoとの複炭化物を形成し、合金粒
子の硬さを向上させるが、Ｗが５％未満ではその
効果が発揮されず、20％を超えると合金粒子が硬
くなり過ぎ、相手材であるバルブへの攻撃性が増
大するため、Ｗは５〜20％とした。 Mo（モリブデン）はＣと化合して硬質炭化物
を形成し、合金粒子の硬さを増すが、Moが５％
未満ではその効果が現れず、20％を超えると合金
粒子が硬くなり過ぎて相手部材を攻撃するので５
〜20％とした。ＣはCr、Mo及びＷと化合して炭化物を形成
し、合金粒子の硬さを向上させるが、Ｃは0.5％
未満ではその効果が発揮されず、３％を超えると
炭化物量が多すぎてもろくなる。そのため、Ｃは
0.5〜３％とした。 Fe（鉄）は特に添加しなくてもよいが、バルブ
シートに必要とする強度等に問題がなければ、高
価なCoの代わりに20％以下の任意の範囲で用い
ることができる。また、Cr、Ｗ、Moを単体とし
てではなくフエロアロイとして合金の原料に用い
る場合に添加されることになる。合金粒子は耐摩耗性の向上に効果があることか
ら用いられる。その粒径は30〜150μmが好まし
く、合金中のCoの一部が基地中に拡散して粒子
の周囲に拡散層を形成することによつて、粒子と
基地との結合力が増し、該粒子の脱落が防止され
る。該合金粒子は５％未満では得られる焼結合金
の耐摩耗効果が発揮されず、25％を超えると成形
性、圧縮性及び被削性が低下するとともに相手材
であるバルブへの攻撃性が増大するため、合金粒
子は５〜25％と限定した。次に基地について説明する。 Cr、Mo、Ｖ（バナジウム）、Mn（マンガン）の
１種又は２種以上を含む鉄基合金の１種又は２種
以上を使用することにより、鉄基地の耐熱性及び
耐食性を向上させることができる。特に、Cr1〜
５％、Mo0.1〜１％及びV0.1〜１％を含む鉄基合
金、Cr0.5〜２％、Mo0.1〜１％及びMn0.1〜１
％を含む鉄基合金又はCr6〜18を含む鉄基合金を
使用することが好ましい。上記鉄基合金中に含ま
れるCr、Mo、Ｖ、Mnの１種又は２種以上は１
％未満では鉄基地の耐熱性・耐食性の向上に対す
る効果がなく、20％超えてもそれ以上の効果が得
られないため、１〜20％とした。Ｃは上記鉄基合金中に拡散して焼結を促進さ
せ、基地を強化させる効果があるとともに、未反
応の遊離黒鉛が、ある程度基地中に内在すること
により、潤滑効果が発揮されるが、Ｃが0.5％未
満ではその効果がなく、20％を超えるとセメンタ
イトが析出し、基地がもろくなつたり、遊離黒鉛
が多すぎて基地の強度が低下するため、Ｃは0.5
〜２％とした。 Ni（ニツケル）はFe基地に固溶して基地の強度
を向上させるのに役立つため、更に強度を必要と
する場合に添加されるが、Niが１％未満ではそ
の効果が発揮されず、10％を超えると基地が軟化
し、耐摩耗性が低下するため、Niは１〜10％と
した。 Pb（鉛）の焼結合金への溶浸は、よりきびしい
条件下で使用されるバルブシートの場合に行われ
る。溶浸されたPbは、バルブとバルブシートの
接触部に介在してPb酸化物層を形成することに
より潤滑剤として作用してバルブ及びバルブシー
ト相互の耐摩耗性を向上させるが、Pbの溶浸が
１％未満ではPb溶浸の効果が発揮されず、20％
を超えて溶浸すると焼結合金のスケルトンが弱化
して摩耗が増大することから１〜20％とした。〔実施例〕本発明を実施例により説明する。実施例１ Cr30％、W10％、Mo10％、Fe10％、C2.5％及
び残部Coからなる合金アトマイズ粉（−100メツ
シユ）15％、黒鉛粉末（−350メツシユ）1.5％、
カルボニルNi粉末（10μm以下）３％、及び粉末
の残部としてCr12％及び残部Feからなる合金ア
トマイズ鉄粉（−100メツシユ）である焼結用粉
末組成に潤滑剤としてステアリン酸亜鉛粉末0.8
％を混合した後、この混合粉末を金型内に充てん
し、成形圧7t／cm²で成形してバルブシート粗形状
の粉末成形体を得た。この粉末成形体をアンモニア分解ガス雰囲気中
で1150℃の温度にて60分間焼結して焼結体を得
た。焼結体密度は7.0ｇ／cm²。得られた焼結体を排気弁座の形状に加工して排
気量2000cc4気筒のデイーゼルエンジンに装着し、
全負荷で200時間台上耐久試験を実施し、バルブ
シート当り面幅増加量及びバルブ摩耗量を測定し
た。なお、相手バルブにはJISNFC751を用いた。実施例２〜４各材料を表１及び表２に示す各組成割合にそれ
ぞれ配合して実施例１と同様に行つて、各焼結体
を得た。なお、実施例３及び４は得られた焼結体
をPb塊と接触させて再度アンモニア分解ガス雰
囲気中で1050℃の温度にて30分間加熱して焼結体
中にPbを溶浸したものである。得られた各焼結体を弁座形状に加工し、バルブ
シート当り面幅増加量及びバルブ摩耗量を実施例
１と同様に試験したのち測定した。実施例５ Cr43％、W16％、Mo17％、Fe8％、C1.5％及
び残部Coからなる合金アトマイズ粉（−100メツ
シユ）15％、黒鉛粉末（−350メツシユ）1.1％、
カルボニルNi粉末（10μm以下）４％、及び粉末
の残部としてCr12％及び残部Feからなる合金ア
トマイズ鉄粉（−100メツシユ）である焼結用粉
末組成に潤滑剤としてステアリン酸亜鉛粉末0.8
％を混合した後、この混合粉末を金型内に充てん
し、成形圧7t／cm²で成形してバルブシート粗形状
の粉末成形体を得た。この粉末成形体をアンモニア分解ガス雰囲気中
で1150℃の温度にて60分間焼結して焼結体を得
た。焼結体密度は6.8ｇ／cm²。得られた焼結体を排気弁座の形状に加工して排
気量2000c.c.４気筒のデイーゼルエンジンに装着
し、全負荷で200時間台上耐久試験を実施し、バ
ルブシート当り面幅増加量及びバルブ摩耗量を測
定した。なお、相手バルブにはJISNFC751を用
いた。実施例６〜８各材料を表１及び表２に示す各組成割合にそれ
ぞれ配合して実施例１と同様に行つて、各焼結体
を得た。なお、実施例７及び８は得られた焼結体
をPb塊と接触させて再度アンモニア分解ガス雰
囲気中で1050℃の温度にて30分間加熱して焼結体
中にPbを溶浸したものである。得られた各焼結体を弁座形状に加工し、バルブ
シート当り面幅増加量及びバルブ摩耗量を実施例
１と同様に試験したのち測定した。比較例１及び２比較例１としてJISFC30鋳鉄、比較例２として
JIS耐熱鋼材SUH4Bをそれぞれ用いて弁座形状
に加工し、これらを実施例１と同様に試験してバ
ルブ摩耗量を測定した。以上の測定結果をまとめて表１に示す。 [Industrial Application Field] The present invention relates to a sintered alloy for a valve seat of an internal combustion engine, and more particularly to an iron-based sintered alloy that has improved wear resistance of the alloy itself and is less aggressive against a mating valve. [Conventional technology] Recently, internal combustion engines for automobiles have been increasing in output and rotation speed.
There is a trend towards lower fuel consumption and measures against exhaust gas. For this reason, valves and valve seat parts are being exposed to more severe conditions than ever before. In order to improve wear resistance at high temperatures, iron-based sintered alloys containing alloying elements such as Cr, Ni, Co, and Mo are increasingly being used for valve seats. [Problems to be solved by the invention] By the way, the valve seat is required to improve its own wear resistance and reduce its aggressiveness to the mating valve, and the selection of the material of the valve seat is dependent on the mating valve and the valve seat. If this selection is incorrect, it will not only weaken the wear resistance of the valve itself, but also increase its aggressiveness against the mating member, which will have an undesirable effect on the entire valve mechanism. Therefore, if a conventional valve seat, for example, which has extremely high wear resistance by simply adding an intermetallic compound such as ferromolybdenum or a composite carbide, is used as it is, the wear of the engine valve will increase. The present invention applies to ordinary general-purpose engine valves that do not have particularly high wear resistance (for example, JIS NFC751
The aim is to avoid abrasion of the mating material or a significant increase in wear of the material itself, even when used as a mating material. [Means for solving the problem] The iron-based sintered alloy for valve seats of the present invention is selected from the group consisting of chromium (Cr), molybdenum (Mo), vanadium (V), and manganese (Mn) in weight ratio. 1 to 20% of one or more selected elements, carbon (C) 0.5 to 2%, optionally (Ni) 1 to 10%
Based on iron-based alloy containing unavoidable impurities, chromium (Cr) 10-70%, tungsten (W) 5-5%
20%, molybdenum (Mo) 5-20%, carbon (C)
It is characterized in that alloy particles consisting of 0.5 to 3%, 20% or less of iron (Fe), and the balance of cobalt (Co) of 5 to 25% are uniformly dispersed in the base. Further, the present invention provides that the sintered alloy contains 1 to 10% of lead (Pb).
Characterized by 20% infiltration. In the present invention, % indicates weight % unless otherwise specified. The reason for limiting each component element used in the present invention will be explained. First, each component element of the alloy particles added as hard particles will be explained. Cr (chromium) in the alloy particles combines with C (carbon) to form carbides, and a portion also forms an alloy with Co, which has the effect of improving the hardness of the alloy particles. If it is less than 70%, the above effect is insufficient, and if it exceeds 70%, the diffusion of Cr will proceed too much to the surrounding base, creating voids inside and at the periphery of the alloy particles, making the alloy particles brittle. Therefore Cr is 10
Limited to ~70%. However, 40-70% is more preferred. W (tungsten) combines with C to form a double carbide of MC-type hard carbide and Co, improving the hardness of the alloy particles, but this effect is not exhibited when W is less than 5%. If the W content exceeds 5%, the alloy particles become too hard and attack against the valve, which is the mating material, increases, so W is set at 5 to 20%. Mo (molybdenum) combines with C to form hard carbides and increases the hardness of alloy particles, but Mo
If it is less than 20%, the effect will not appear, and if it exceeds 20%, the alloy particles will become too hard and attack the mating material.
~20%. C combines with Cr, Mo and W to form carbides and improves the hardness of alloy particles, but C is 0.5%
If it is less than 3%, the effect will not be exhibited, and if it exceeds 3%, the amount of carbide will be too large and it will become brittle. Therefore, C is
It was set at 0.5 to 3%. Fe (iron) does not need to be particularly added, but if there is no problem with the strength required for the valve seat, it can be used in any range of 20% or less in place of the expensive Co. Furthermore, when Cr, W, and Mo are used as raw materials for alloys as ferroalloys rather than as single substances, they are added. Alloy particles are used because they are effective in improving wear resistance. The particle size is preferably 30 to 150 μm, and a part of the Co in the alloy diffuses into the matrix to form a diffusion layer around the particles, increasing the bonding force between the particles and the matrix. is prevented from falling off. If the alloy particles are less than 5%, the resulting sintered alloy will not exhibit its wear-resistance effect, and if it exceeds 25%, the formability, compressibility, and machinability will decrease, and the mating material, the valve, will be attacked. The alloy particles were limited to 5 to 25% due to the increase in the amount of alloy particles. Next, I will explain the base. By using one or more iron-based alloys containing one or more of Cr, Mo, V (vanadium), and Mn (manganese), the heat resistance and corrosion resistance of the iron base can be improved. can. In particular, Cr1~
5%, Mo0.1~1% and V0.1~1%, Cr0.5~2%, Mo0.1~1% and Mn0.1~1
It is preferable to use iron-based alloys containing Cr6-18%. One or more of Cr, Mo, V, and Mn contained in the above iron-based alloy is 1
If it is less than 20%, there is no effect on improving the heat resistance and corrosion resistance of the iron base, and if it exceeds 20%, no further effect can be obtained, so it was set at 1 to 20%. C diffuses into the iron-based alloy, promotes sintering, and has the effect of strengthening the matrix, and a certain amount of unreacted free graphite remains in the matrix, thereby exerting a lubricating effect. If C is less than 0.5%, it has no effect, and if it exceeds 20%, cementite will precipitate and the base will become brittle, or there will be too much free graphite, reducing the strength of the base, so C is 0.5%.
~2%. Ni (nickel) dissolves in the Fe base and helps improve the strength of the base, so it is added when further strength is required, but if Ni is less than 1%, its effect will not be exhibited, and 10 If the Ni content exceeds 1%, the base becomes soft and the wear resistance decreases, so the Ni content was set to 1 to 10%. Infiltration of sintered alloys with Pb (lead) is carried out in the case of valve seats used under more severe conditions. The infiltrated Pb acts as a lubricant by forming a Pb oxide layer at the contact area between the valve and the valve seat, improving mutual wear resistance between the valve and the valve seat. If the Pb infiltration is less than 1%, the effect of Pb infiltration will not be exhibited;
If infiltration exceeds 1%, the skeleton of the sintered alloy will weaken and wear will increase, so it was set at 1% to 20%. [Example] The present invention will be explained with reference to an example. Example 1 Alloy atomized powder (-100 mesh) 15%, graphite powder (-350 mesh) 1.5%, consisting of 30% Cr, 10% W, 10% Mo, 10% Fe, 2.5% C, and the balance Co.
The powder composition for sintering is an alloy atomized iron powder (-100 mesh) consisting of carbonyl Ni powder (10 μm or less) 3%, and the balance of the powder is 12% Cr and the balance Fe, and 0.8% zinc stearate powder as a lubricant.
%, this mixed powder was filled into a mold and molded at a molding pressure of 7 t/cm ² to obtain a powder molded body in the rough shape of a valve seat. This powder compact was sintered at a temperature of 1150°C for 60 minutes in an ammonia decomposition gas atmosphere to obtain a sintered body. The density of the sintered body is 7.0g/cm ² . The obtained sintered body was processed into the shape of an exhaust valve seat and installed in a 2000cc 4-cylinder diesel engine.
A bench durability test was conducted for 200 hours under full load, and the amount of increase in the face width per valve seat and the amount of valve wear were measured. In addition, JISNFC751 was used for the mating valve. Examples 2 to 4 Each material was blended in the respective composition ratios shown in Tables 1 and 2, and the same procedure as in Example 1 was carried out to obtain each sintered body. In addition, in Examples 3 and 4, the obtained sintered body was brought into contact with a Pb lump and heated again at a temperature of 1050°C for 30 minutes in an ammonia decomposition gas atmosphere to infiltrate Pb into the sintered body. It is. Each of the obtained sintered bodies was processed into a valve seat shape, and the increase in surface width per valve seat and the amount of valve wear were tested and measured in the same manner as in Example 1. Example 5 Alloy atomized powder (-100 mesh) 15%, graphite powder (-350 mesh) 1.1%, consisting of 43% Cr, 16% W, 17% Mo, 8% Fe, 1.5% C, and the balance Co.
The powder composition for sintering is an alloy atomized iron powder (-100 mesh) consisting of carbonyl Ni powder (10 μm or less) 4%, and the balance of the powder is 12% Cr and the balance Fe, and 0.8% zinc stearate powder as a lubricant.
%, this mixed powder was filled into a mold and molded at a molding pressure of 7 t/cm ² to obtain a powder molded body in the rough shape of a valve seat. This powder compact was sintered at a temperature of 1150°C for 60 minutes in an ammonia decomposition gas atmosphere to obtain a sintered body. The density of the sintered body is 6.8g/cm ² . The obtained sintered body was processed into the shape of an exhaust valve seat and installed in a 2000 c.c. 4-cylinder diesel engine, and a bench durability test was conducted for 200 hours under full load, which resulted in an increase in the surface width of the valve seat. The amount of wear and valve wear were measured. In addition, JISNFC751 was used for the mating valve. Examples 6 to 8 Each material was blended in the respective composition ratios shown in Tables 1 and 2, and the same procedure as in Example 1 was carried out to obtain each sintered body. In Examples 7 and 8, the obtained sintered body was brought into contact with a Pb lump and heated again at a temperature of 1050°C for 30 minutes in an ammonia decomposition gas atmosphere to infiltrate Pb into the sintered body. It is. Each of the obtained sintered bodies was processed into a valve seat shape, and the increase in surface width per valve seat and the amount of valve wear were tested and measured in the same manner as in Example 1. Comparative Examples 1 and 2 JISFC30 cast iron as Comparative Example 1, and JISFC30 cast iron as Comparative Example 2
JIS heat-resistant steel SUH4B was used to form a valve seat shape, and these were tested in the same manner as in Example 1 to measure the amount of valve wear. The above measurement results are summarized in Table 1.

【表】＊組成は表２に示す。
[Table] *The composition is shown in Table 2.

〔Effect of the invention〕

本発明のバルブシート用鉄系焼結合金は上記し
たように合金粒子をCr、Mo、Ｖ、Mnの１種又
は２種以上を含む鉄基合金基地中に均一に分散さ
せたので、耐摩耗性に優れ、かつ相手材であるバ
ルブに対する攻撃性が低く、バルブシート用焼結
合金として最適なものである。 As mentioned above, the iron-based sintered alloy for valve seats of the present invention has alloy particles uniformly dispersed in the iron-based alloy base containing one or more of Cr, Mo, V, and Mn, so it has excellent wear resistance. This sintered alloy is ideal as a sintered alloy for valve seats, as it has excellent properties and low aggressiveness against the mating material, the valve.

Claims

[Claims] 1 Chromium (Cr), molybdenum (Mo), vanadium (V), and manganese (Mn) in weight ratio
One or more elements selected from the group consisting of1
~20%, carbon (C) 0.5~2% and unavoidable impurities as a base, based on an iron-based alloy containing chromium (Cr) 10~70%, tungsten (W) 5~20%,
Molybdenum (Mo) 5-20%, carbon (C) 0.5-3
%, iron (Fe) 20% or less, balance cobalt (Co)
An iron-based sintered alloy for a valve seat, characterized in that 5 to 25% of alloy particles consisting of the following are uniformly dispersed in the matrix. 2 By weight, chromium (Cr) 1-5%, molybdenum (Mo) 0.1-1%, and vanadium (V) 0.1
The iron-based sintered alloy for a valve seat according to claim 1, characterized in that the iron-based alloy contains ~1% of the iron-based sintered alloy. 3 By weight, chromium (Cr) 0.5-2%, molybdenum (Mo) 0.1-1%, and manganese (Mn) 0.1-2%
The iron-based sintered alloy for a valve seat according to claim 1, characterized in that the iron-based sintered alloy contains 1% of the iron-based alloy. 4. Claim 1, characterized in that the iron-based alloy contains 6 to 18% chromium (Cr) by weight.
Iron-based sintered alloy for valve seats as described in . 5. The iron-based sintered alloy for a valve seat according to claim 1, wherein the content of chromium (Cr) in the alloy particles is 40 to 70% by weight. 6 Chromium (Cr), molybdenum (Mo), vanadium (V), and manganese (Mn) in weight ratio
One or more elements selected from the group consisting of1
~20%, carbon (C) 0.5-2%, nickel (Ni)
Based on an iron-based alloy containing 1-10% and unavoidable impurities, the weight ratio is 10-70% chromium (Cr), 5-20% tungsten (W), and 5% molybdenum (Mo).
Alloy particles 5 consisting of ~20%, carbon (C) 0.5 to 3%, iron (Fe) 20% or less, and the balance cobalt (Co)
An iron-based sintered alloy for a valve seat, characterized in that ~25% is uniformly dispersed in the base. 7 By weight, chromium (Cr) 1-5%, molybdenum (Mo) 0.1-1%, and vanadium (V) 0.1
The iron-based sintered alloy for valve seats according to claim 6, characterized in that the iron-based alloy contains ~1% of the iron-based sintered alloy. 8 By weight, chromium (Cr) 0.5~2%, molybdenum (Mo) 0.1~1%, and manganese (Mn) 0.1~
The iron-based sintered alloy for a valve seat according to claim 6, characterized in that the iron-based sintered alloy contains 1% of the iron-based alloy. 9. Claim 6, characterized in that the iron-based alloy contains 6 to 18% chromium (Cr) by weight.
Iron-based sintered alloy for valve seats as described in . 10. The iron-based sintered alloy for a valve seat according to claim 6, wherein the content of chromium (Cr) in the alloy particles is 40 to 70% by weight. 11 Chromium (Cr), molybdenum (Mo), vanadium (V), and manganese (Mn) in weight ratio
One or more elements selected from the group consisting of1
~20%, carbon (C) 0.5~2% and unavoidable impurities as a base, based on an iron-based alloy containing chromium (Cr) 10~70%, tungsten (W) 5~20%,
Molybdenum (Mo) 5-20%, carbon (C) 0.5-3
%, iron (Fe) 20% or less, balance cobalt (Co)
1. An iron-based sintered alloy for a valve seat, characterized in that 1-20% of lead (Pb) is infiltrated into the sintered alloy made by uniformly dispersing 5-25% of alloy particles in the base. 12 By weight, chromium (Cr) 1-5%, molybdenum (Mo) 0.1-1% and vanadium (V)
The iron-based sintered alloy for a valve seat according to claim 11, characterized in that the iron-based alloy contains 0.1 to 1% of the iron-based sintered alloy. 13 By weight, chromium (Cr) 0.5-2%, molybdenum (Mo) 0.1-1%, and manganese (Mn) 0.1
12. The iron-based sintered alloy for a valve seat according to claim 11, wherein the iron-based sintered alloy contains ~1% of the iron-based alloy. 14. The iron-based sintered alloy for a valve seat according to claim 11, wherein the iron-based alloy contains chromium (Cr) in an amount of 6 to 18% by weight. 15. The iron-based sintered alloy for a valve seat according to claim 11, wherein the content of chromium (Cr) in the alloy particles is 40 to 70% by weight. 16 Chromium (Cr), molybdenum (Mo), vanadium (V), and manganese (Mn) in weight ratio
One or more elements selected from the group consisting of1
~20%, carbon (C) 0.5-2%, nickel (Ni)
Based on an iron-based alloy containing 1-10% and unavoidable impurities, the weight ratio is 10-70% chromium (Cr), 5-20% tungsten (W), and 5% molybdenum (Mo).
Alloy particles 5 consisting of ~20%, carbon (C) 0.5 to 3%, iron (Fe) 20% or less, and the balance cobalt (Co)
An iron-based sintered alloy for a valve seat, characterized in that 1 to 20% of lead (Pb) is infiltrated into a sintered alloy in which 1 to 25% of lead (Pb) is uniformly dispersed in the matrix. 17 By weight, chromium (Cr) 1-5%, molybdenum (Mo) 0.1-1% and vanadium (V)
The iron-based sintered alloy for a valve seat according to claim 16, characterized in that the iron-based alloy contains 0.1 to 1% of the iron-based sintered alloy. 18 By weight, chromium (Cr) 0.5-2%, molybdenum (Mo) 0.1-1%, and manganese (Mn) 0.1
17. The iron-based sintered alloy for a valve seat according to claim 16, wherein the iron-based sintered alloy contains ~1% of the iron-based alloy. 19. The iron-based sintered alloy for a valve seat according to claim 16, characterized in that the iron-based alloy contains 6 to 18% chromium (Cr) by weight. 20. The iron-based sintered alloy for a valve seat according to claim 16, wherein the content of chromium (Cr) in the alloy particles is 40 to 70% by weight.