JPH03267354A - Sintered alloy for valve seat - Google Patents
Sintered alloy for valve seatInfo
- Publication number
- JPH03267354A JPH03267354A JP6796690A JP6796690A JPH03267354A JP H03267354 A JPH03267354 A JP H03267354A JP 6796690 A JP6796690 A JP 6796690A JP 6796690 A JP6796690 A JP 6796690A JP H03267354 A JPH03267354 A JP H03267354A
- Authority
- JP
- Japan
- Prior art keywords
- valve
- sintered alloy
- valve seat
- alloy
- wear resistance
- 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.)
- Granted
Links
- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 34
- 239000000956 alloy Substances 0.000 title claims abstract description 34
- 229910000604 Ferrochrome Inorganic materials 0.000 claims abstract description 7
- 239000000843 powder Substances 0.000 claims abstract description 6
- 229910052727 yttrium Inorganic materials 0.000 claims abstract description 6
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 5
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 5
- 239000012535 impurity Substances 0.000 claims abstract description 4
- 229910052802 copper Inorganic materials 0.000 claims abstract description 3
- 229910052745 lead Inorganic materials 0.000 claims abstract description 3
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 3
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 3
- 229910052718 tin Inorganic materials 0.000 claims abstract 2
- 239000002245 particle Substances 0.000 claims description 24
- 229910052684 Cerium Inorganic materials 0.000 claims description 5
- 239000011159 matrix material Substances 0.000 abstract description 9
- 239000000203 mixture Substances 0.000 abstract description 7
- 229910017112 Fe—C Inorganic materials 0.000 abstract description 5
- 230000013011 mating Effects 0.000 abstract description 5
- 238000002485 combustion reaction Methods 0.000 abstract description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 abstract 1
- 229910052804 chromium Inorganic materials 0.000 abstract 1
- 238000000034 method Methods 0.000 abstract 1
- 239000000463 material Substances 0.000 description 19
- 230000000694 effects Effects 0.000 description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 7
- 230000008595 infiltration Effects 0.000 description 5
- 238000001764 infiltration Methods 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 229910000978 Pb alloy Inorganic materials 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 229910001309 Ferromolybdenum Inorganic materials 0.000 description 2
- 229910000756 V alloy Inorganic materials 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000005552 hardfacing Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 229910000765 intermetallic Inorganic materials 0.000 description 1
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical group C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229910001562 pearlite Inorganic materials 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
Abstract
Description
【発明の詳細な説明】
［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。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sintered alloy for valve seats of automobile internal combustion engines.
し従来の技術］
自動車エンジンの動弁系の断面図は第１図に示す通りで
あって、インテークバルブ７のフェース部１６は、バル
ブの上下運動によってバルブシート９と接触する。この
インテークバルブの作動温度は１００〜４５０℃であり
、従来から作動温度での軟化抵抗が大で、耐食性、疲労
強度と併せて高温強度の大きい５ＵＨＩ、３．４．１１
が使用されている。BACKGROUND ART A cross-sectional view of a valve train of an automobile engine is shown in FIG. 1, and the face portion 16 of the intake valve 7 comes into contact with the valve seat 9 due to the vertical movement of the valve. The operating temperature of this intake valve is 100 to 450°C, and conventionally 5UHI, which has high softening resistance at operating temperature, high temperature strength as well as corrosion resistance and fatigue strength, is 3.4.11
is used.
最近、自動車エンジンにおいて、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条件に耐えることが不可避と
なってきている。Recently, there has been an increasing demand for improvements in automobile engines, such as higher output, higher rotation speed, measures to purify exhaust gas, and measures to improve fuel efficiency. For this reason, it has become inevitable for engine valves and valve seats in automobile engines to withstand harsher usage environmental conditions than ever before.
かかる厳しい使用環境に対応するため、耐摩耗性に優れ
高温における硬さと高温腐食に対する抵抗の高いＣｏ基
またはＮｉ基の盛会合金を弁フエース部に溶着するハー
ドフェーシングが採用されてきた。しかし、このハード
フェーシングは高価な盛会を使用するため、高価であり
、そのためコストダウンの要請からフェース部の盛会を
廃止したインテークバルブが使われることも多くなって
きた。In order to cope with such severe usage environments, hard facings have been adopted in which Co-based or Ni-based alloy alloys, which have excellent wear resistance, high hardness at high temperatures, and high resistance to high-temperature corrosion, are welded to the valve face. However, this hard facing is expensive because it uses expensive facings, and therefore, in order to reduce costs, intake valves that do not have facings on the face are increasingly being used.
また、従来のバルブシート材料としては、ＦｅＣ−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（Ｆ
ｅ−Ｃｒ）等の金属間化合物またはＦｅ−Ｃ−Ｃｒ−Ｍ
ｏ−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）。また、ＯｒおよびＭＯを
含有するＦｅ−Ｃ基地組織中に、Ｃｒｓ Ｍ ０％ Ｖ
等からなる鉄系の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６（１２２４７６２）
、Ｐｂ合金等を含浸させたＦｅ−Ｃ−Ｇｏ−Ｎｉ系基地
組織中にＦｅ−Ｃ−Ｃｒ−Ｍｏ−Ｖ合金からなる硬質粒
子を分散させた焼結合金（特開昭６Ｏ−２５１２５８）
等が開示されている。In addition, as a conventional valve seat material, FeC-co
- Ferromolybdenum (Fe-Mo) and ferrochrome (F) are added to Ni-based materials and Fe-C-based materials to improve wear resistance.
intermetallic compounds such as e-Cr) or Fe-C-Cr-M
A material to which an o-V alloy or the like is added is used (Japanese Unexamined Patent Publication No. 154110/1983). In addition, in the Fe-C base structure containing Or and MO, Crs M 0% V
A sintered alloy with improved wear resistance and attackability by dispersing iron-based hard particles consisting of
, a sintered alloy in which hard particles made of Fe-C-Cr-Mo-V alloy are dispersed in a Fe-C-Go-Ni matrix structure impregnated with Pb alloy etc. (Japanese Patent Application Laid-Open No. 6O-251258)
etc. are disclosed.
［発明が解決しようとする課題］
ところで、エンジンの吸排気バルブシートは、それ自体
の耐摩耗性を改善する必要があるが、さらに相手材すな
わちバルブに対する相手攻撃性の少ないことが要求され
る。バルブシート材料の耐摩耗性向上策としては、基地
組織に分散する硬質粒子の量を多くしたり、粒子径を大
きくしたり、あるいはマクロ硬さを硬くしたりする。[Problems to be Solved by the Invention] Incidentally, engine intake and exhaust valve seats need to improve their own wear resistance, but are also required to have less aggressiveness against a mating material, that is, a valve. Measures to improve the wear resistance of valve seat materials include increasing the amount of hard particles dispersed in the matrix structure, increasing the particle diameter, or increasing the macro hardness.
しかし、このようにしてバルブシート材料の耐摩耗性を
向−ヒした場合、相手攻撃性が高くなり、バルブが摩耗
するという問題点がある。そのため、バルブシート材料
の相手攻撃性を下げる方策として、硬さをＨｖｌ ＯＯ
Ｏ以下に下げた硬質粒子を使い、相手攻撃性を下げると
いうことが行なわれている。However, when the abrasion resistance of the valve seat material is improved in this way, there is a problem that the abrasion resistance of the valve seat material increases and the valve wears out. Therefore, as a measure to reduce the aggressiveness of the valve seat material, the hardness has been increased to Hvl OO
Hard particles lowered to below 0 are used to lower the opponent's aggressiveness.
それでも、最高回転数が１万回に近付いた場合や、使用
寿命が１０万ｋｍ以上になると、従来技術ではバルブお
よびバルブシートの摩耗を防ぐことができない。また、
バルブシート表面にできる酸化膜は、バルブとの金属接
触を防止して、耐摩耗性を向上させるが、Ｆｅの酸化物
では密着性が弱く、作動中に剥がれてしまい、酸化膜が
無いためバルブとの間で凝着が発生し、バルブシートが
摩耗していくという問題点がある。Even so, when the maximum rotational speed approaches 10,000 rotations or when the service life exceeds 100,000 km, conventional techniques cannot prevent valve and valve seat wear. Also,
The oxide film that forms on the valve seat surface prevents metal contact with the valve and improves wear resistance, but Fe oxide has weak adhesion and peels off during operation. There is a problem that adhesion occurs between the valve seats and the valve seats wear out.
例えば、前記特開昭６０−２２４７６２号公報の発明で
は、基地強化および耐熱性向上のためのＣｏが含有され
ておらず、高温の厳しい条件では高温硬さおよび耐酸化
性が不足し、Ｆｅの厚い酸化膜ができ、この層が剥離し
易いため、バルブシートが摩耗するという問題点がある
。For example, the invention disclosed in JP-A-60-224762 does not contain Co to strengthen the base and improve heat resistance, and under severe high-temperature conditions, high-temperature hardness and oxidation resistance are insufficient. There is a problem that a thick oxide film is formed and this layer easily peels off, causing wear of the valve seat.
また、前記特開昭６０−２５１２５８号公報の発明では
、Ｃｏを含有し耐熱性に優れるものの、ｃｏが酸化しな
いため、表面に酸化皮膜層ができにくく、低温雰囲気時
（バルブシート温度が１００℃程度）の場合、特にバル
ブシート表面が酸化されず、凝着を伴う摩耗が発生する
ことがある。In addition, although the invention disclosed in JP-A-60-251258 contains Co and has excellent heat resistance, since Co does not oxidize, it is difficult to form an oxide film layer on the surface. In cases where the valve seat surface is not oxidized, wear accompanied by adhesion may occur.
本発明はバルブシート用焼結合金の前記のごとき問題点
を解決すべくなされたものであって、耐摩耗性を保持し
ながら相手バルブに対する攻撃性が低く、かつ強固な酸
化皮膜が形成されて摩耗が発生しないバルブシート用焼
結合金を提供することを目的とする。The present invention has been made to solve the above-mentioned problems of sintered alloys for valve seats, and has a structure that maintains wear resistance, has low aggressiveness against mating valves, and forms a strong oxide film. The purpose of the present invention is to provide a sintered alloy for a valve seat that does not cause wear.
［課題を解決するための手段］
本発明のバルブシート用焼結合金は、重量比で、Ｃ，０
，４−２，０％、ＮｉまたはＣｏの１種または２種：１
０〜２０％、ＹまたはＣｅの１種または２種：０．２〜
３％、Ａ１．０．５〜１５％を含有し、残部がＦｅおよ
び不純物元素からなる基地組織に、ＦｅＭｏ、ＦｅＣｒ
、ＦｅＷ、ＦｅＮｂまたは重量比でＣｒ；４〜１８％、
Ｖ；０．１−０．５％、Ｍｏ；０．２〜２％、Ｃ：０．
８〜２％を含有し、残部がＦｅおよび不純物元素からな
るＦｅ系合金粉末から選ばれた１種または２種以上から
なる、粒径が２０〜２００μｍの硬質粒子を３〜２０重
量％均一に分散させた焼結合金に、Ｐｂ、ＣｕＳＳｎま
たはそれらの合金を５〜２５重量％溶浸させたことを要
旨とする。[Means for Solving the Problems] The sintered alloy for valve seats of the present invention has a weight ratio of C.0
,4-2,0%, one or two of Ni or Co: 1
0 to 20%, one or two of Y or Ce: 0.2 to
FeMo, FeCr
, FeW, FeNb or Cr by weight ratio; 4-18%,
V: 0.1-0.5%, Mo: 0.2-2%, C: 0.
Hard particles having a particle size of 20 to 200 μm and consisting of one or more selected from Fe-based alloy powder containing 8 to 2% and the balance consisting of Fe and impurity elements are uniformly distributed at 3 to 20% by weight. The gist is that the dispersed sintered alloy is infiltrated with 5 to 25% by weight of Pb, CuSSn, or an alloy thereof.
［作用コ
本発明のバルブシート用焼結合金は、Ｎ１およびＣｏを
含有するＦｅ−Ｃ系基地組織に、酸化し易いＡ１を含有
させて表面にち密で薄いＡ１酸化皮膜を形成すると同時
に、ＹおよびＣｅを含有させて酸化皮膜と基材を強く結
びつけて、酸化皮膜の剥離を防止したものである。[Function] The sintered alloy for valve seats of the present invention contains easily oxidized A1 in the Fe-C base structure containing N1 and Co to form a dense and thin A1 oxide film on the surface, and at the same time and Ce to strongly bind the oxide film and the base material and prevent the oxide film from peeling off.
また、ＦｅＭｏ、ＦｅＣｒ、ＦｅＷ等からなる硬質粒子
を基地組織に分散させて耐摩耗性の確保を図ると共に、
その硬質粒子の分散量、粒径を規制することにより、相
手バルブに対する攻撃性を低下させている。さらに、Ｐ
ｂ合金等の溶浸合金を溶浸したので、耐摩耗性が向上し
、被削性が改善された。In addition, hard particles made of FeMo, FeCr, FeW, etc. are dispersed in the base structure to ensure wear resistance.
By regulating the amount and particle size of the hard particles dispersed, the aggressiveness towards the other valve is reduced. Furthermore, P
Since the infiltration alloy such as b-alloy was infiltrated, wear resistance and machinability were improved.
次に、本発明のバルブソート用焼結合金の基地組織を形
成する成分の組成範囲の限定理由について説明する。Next, the reason for limiting the composition range of the components forming the matrix structure of the sintered alloy for valve sorting of the present invention will be explained.
ＣはＦｅと反応してオーステナイト組織とパーライト組
織の混合組織からなる基地組織中に固溶し、焼結反応を
促進させるが、０．５％以下では前記効果が充分でなく
、２．０％以上では、セメンタイト組織が多量に析出し
、焼結体を脆化することから、その組成範囲を０．５〜
２．０％とした。C reacts with Fe and becomes a solid solution in the base structure consisting of a mixed structure of austenite structure and pearlite structure, promoting the sintering reaction, but if it is less than 0.5%, the above effect is not sufficient; In the above, since a large amount of cementite structure precipitates and embrittles the sintered body, the composition range is set from 0.5 to
It was set at 2.0%.
ＧｏとＮｉは同じ効果を持ち、一方まはた両方を合わせ
て含有させても同じ作用をする。ＣＯおよびＮｉは基地
組織中に固溶し、基地組織を強化するとともに、耐熱性
を改善するので有効であるが、１．０％未満では前記効
果が充分でなく、２０％を越えて含有させても前記効果
が飽和してコスト高となるので、これら元素の含有量は
１．０〜２０％に限定した。Go and Ni have the same effect, and even if one or both are contained, the same effect will occur. CO and Ni are effective because they form a solid solution in the base structure, strengthen the base structure, and improve heat resistance. However, if the content is less than 1.0%, the above effect is not sufficient, and if the content exceeds 20%, it is effective. However, the above effects would be saturated and the cost would be high, so the content of these elements was limited to 1.0 to 20%.
Ｐｂ、Ｐｂ合金、Ｃｕ、Ｃｕ合金は、焼結処理後に焼結
合金に溶浸させ、その潤滑作用により耐摩耗性を向上さ
せ、封孔作用によって被削性を改善するために有効であ
る。これら溶浸金属の溶浸量が５％未満であると、その
効果が充分でなく、溶浸量が２５％を越えると、焼結合
金の強度低下が著しくなることから、これら溶浸金属の
溶浸量は５〜２５％に限定した。Pb, Pb alloy, Cu, and Cu alloy are effective in infiltrating the sintered alloy after sintering to improve wear resistance through their lubricating action and improving machinability through their sealing action. If the infiltration amount of these infiltrated metals is less than 5%, the effect will not be sufficient, and if the infiltration amount exceeds 25%, the strength of the sintered alloy will decrease significantly. The amount of infiltration was limited to 5-25%.
ＡＩは酸化し易いため、早期に薄いＡ１の酸化皮膜を形
成し、バルブとの凝着を防止して耐摩耗性を向上させる
。Ａｔ含有量が０．５％未満ではバルブシート表面に酸
化物層が形成されにくい。また、１５％以上含有させる
と、フェライトまたはオーステナイト量が増加してしま
い、基地組織の硬さを低下させるたぬ、Ａｔ含有量は０
．５〜１５％に限定した。Since AI is easily oxidized, a thin oxide film of Al is formed at an early stage to prevent adhesion to the valve and improve wear resistance. When the At content is less than 0.5%, an oxide layer is hardly formed on the valve seat surface. In addition, if the At content exceeds 15%, the amount of ferrite or austenite increases, which reduces the hardness of the matrix structure, and the At content becomes 0.
．． It was limited to 5-15%.
ＹとＣｅは基地とＡ１酸化物層の間で酸化層を形成して
ＡＩ酸化物を基地に密着させるのに有効である。Ｙおよ
び／またはＣｅの含有量が０．２％未満では充分な酸化
物層が形成されず、３％を越えて含有しても、前記効果
の向上が望めないので、その組成範囲を０，２〜３％に
限定した。Y and Ce are effective in forming an oxide layer between the base and the A1 oxide layer and adhering the AI oxide to the base. If the content of Y and/or Ce is less than 0.2%, a sufficient oxide layer will not be formed, and if the content exceeds 3%, no improvement in the above effect can be expected. It was limited to 2-3%.
ＦｅＭｏ、ＦｅＣｒ、ＦｅＷ、ＦｅＮｂまたはＦｅ系合
金粉末からなる硬質粒子は、基地組織中に均一に分散さ
れバルブシート材料の耐摩耗性を向上する。The hard particles made of FeMo, FeCr, FeW, FeNb or Fe-based alloy powder are uniformly dispersed in the matrix structure and improve the wear resistance of the valve seat material.
硬質粒子の大きさが２０μ會未満では耐摩耗性の向上が
得られず、２００μ−を越えると相手攻撃性が大きくな
るため、硬質粒子の粒径は２０〜２００μｍこ限定した
。また、硬質粒子の添加量は３％未満では耐摩耗性の向
上がみられず、２０％を越えると、相手攻撃性が大きく
なるので、硬質粒子の添加量は３〜２０％に限定した。If the size of the hard particles is less than 20 μm, no improvement in wear resistance can be obtained, and if the size exceeds 200 μm, the aggressiveness against the other party increases. Therefore, the particle size of the hard particles is limited to 20 to 200 μm. Further, if the amount of hard particles added is less than 3%, no improvement in wear resistance is observed, and if it exceeds 20%, the aggressiveness towards the other party increases, so the amount of hard particles added was limited to 3 to 20%.
［実施例コ
本発明の実施例を比較例とともに説明し、本発明の効果
を明らかにする。[Example] Examples of the present invention will be explained together with comparative examples to clarify the effects of the present invention.
第１表に示す組成からなる基地組織用合金粉末に、第１
表に示す組成および粒径からなる硬質粒子を、第１表に
示す割合で調合し、これに黒鉛粉末および潤滑剤として
ステアリン酸亜鉛を混合した後、この混合粉末を金型内
に充填して、成形圧７ｔ／ｃｍ”で成形してφ４０ｍｍ
Ｘ８ｍｍの圧粉成形体を得た。なお、第１表において、
番号１〜６は本発明材であり、番号７〜９は基地組織に
ＡＩ、ＹおよびＣｅを含有しない比較材である。In the alloy powder for matrix structure having the composition shown in Table 1,
Hard particles having the composition and particle size shown in the table are mixed in the proportions shown in Table 1, graphite powder and zinc stearate are mixed therein as a lubricant, and then this mixed powder is filled into a mold. , molded at a molding pressure of 7t/cm" to a diameter of 40mm.
A compacted powder body having a size of 8 mm was obtained. In addition, in Table 1,
Numbers 1 to 6 are materials of the present invention, and numbers 7 to 9 are comparative materials that do not contain AI, Y, and Ce in the matrix structure.
この圧粉成形体をアンモニア分解ガス雰囲気中で１１５
０℃の温度にて、６０分間焼結して焼結体を得た。次に
この焼結体をＰｂ等と接触させて、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
焼結体中に第１表に示した割合でＰｂ等の溶浸合金を溶
浸した。This compacted compact was heated to 115°C in an ammonia decomposition gas atmosphere.
A sintered body was obtained by sintering at a temperature of 0° C. for 60 minutes. Next, this sintered body is brought into contact with Pb, etc., and heated again at a temperature of 1050°C for 30 minutes in an ammonia decomposition gas atmosphere to infiltrate Pb, etc. into the sintered body at the ratio shown in Table 1. The alloy was infiltrated.
（以 下 余 白 ）
得られた焼結体を排気バルブシート状に加工して排気量
２０００ｃｃ、４気筒のエンジンに装着し、無鉛ガソリ
ンを用い、回転数５００ Ｏｒｐｍ、全負荷で１０００
時間の台上耐久試験を実施し、バルブ沈み量およびバル
ブシート表面酸化膜厚さを測定した。なお、バルブ沈み
量は第２図のエンジンの部分断面図に示したように、試
験前のバルブのアップダウン幅Ｔから試験後のバルブの
アップダウン幅ｔを差し引いたものによって示した。(Left below) The obtained sintered body was processed into an exhaust valve sheet shape and installed in a 4-cylinder engine with a displacement of 2000 cc, using unleaded gasoline at a rotation speed of 500 Orpm and 1000 rpm at full load.
An hour bench durability test was conducted to measure the amount of valve sinking and the thickness of the oxide film on the valve seat surface. As shown in the partial sectional view of the engine in FIG. 2, the amount of valve depression is shown by subtracting the valve up-down width T after the test from the valve up-down width T before the test.
得られた結果は第２表に示した。The results obtained are shown in Table 2.
（以 下 余 白 ）
区ネ
タ ｉ −
云 ご 本
第
表
（なお、番号８の表面酸化膜は１５μ論であるが、表面
から浮き上がっている所があり、剥離部もあった。）
第２表に示した結果より明らかなように、比較材のバル
ブ沈み量が０．２０〜０．３３μ−であるのに対して、
本発明材は０．０５〜０．０８μ−であって、本発明の
バルブシート用焼結合金は、耐摩耗性に優れるとともに
、相手バルブに対する攻撃性の低いことが確認された。(Left below) Table 2 (Although the surface oxide film in number 8 is 15 μm thick, there are some areas where it is raised from the surface and there are peeling areas.) Table 2 As is clear from the results shown in , the amount of valve sinking of the comparative material is 0.20 to 0.33 μ-, whereas
The material of the present invention has a particle diameter of 0.05 to 0.08 μ-, and it was confirmed that the sintered alloy for a valve seat of the present invention has excellent wear resistance and low aggressiveness against a mating valve.
また、バルブシートの表面酸化膜は、比較材については
２〜３μｍと薄いものであるか、または１５μｌのもの
では浮き上がって剥離部があるのに対し、本発明材では
表面酸化膜が８〜１２μｍと厚いものであって、浮き−
Ｌがりゃ剥離が観察されず、本発明材では強固な酸化膜
の形成により、凝着による過大摩耗が防止できることが
確認された。In addition, the surface oxide film of the valve seat of the comparative material is as thin as 2 to 3 μm, or that of the 15 μl version has peeling parts, whereas the surface oxide film of the inventive material is 8 to 12 μm thick. It is thick and floating.
No peeling was observed in the case of L, confirming that the material of the present invention can prevent excessive wear due to adhesion due to the formation of a strong oxide film.
［発明の効果１
本発明のバルブシート用焼結合金は、ＮｉおよびＣｏを
含有するＦｅ−Ｃ系基地組織に、酸化し易いＡＩを含有
させて表面にち密で薄いＡ１酸化皮膜を形成すると同時
に、ＹおよびＣｅを含有させて酸化皮膜と基材を強く結
びつけて、酸化皮膜の剥離を防止したので、バルブとバ
ルブシートとの接触が酸化層を介して行なわれ、凝着に
よる過大摩耗が防止される。また、ＦｅＭｏ、ＦｅＣｒ
、ＦｅＷ等からなる硬質粒子を基地組織に分散させて耐
摩耗性の確保を図ると共に、その硬質粒子の分散量、粒
径を規制したので相手バルブに対する攻撃性を低下する
ことができた。そのため、バルブおよびバルブシートの
寿命を著しく向上する。さらに、Ｐｂ合金等の溶浸合金
を溶浸したので、耐摩耗性が向上し、被削性が改善され
た。[Effect of the invention 1] The sintered alloy for valve seats of the present invention contains easily oxidized AI in the Fe-C base structure containing Ni and Co to form a dense and thin A1 oxide film on the surface. , Y, and Ce to strongly bind the oxide film to the base material and prevent the oxide film from peeling off.This allows contact between the valve and the valve seat to occur through the oxide layer, preventing excessive wear due to adhesion. be done. Also, FeMo, FeCr
Hard particles made of , FeW, etc. are dispersed in the base structure to ensure wear resistance, and the amount of dispersed hard particles and particle size are regulated, making it possible to reduce the aggressiveness against the mating valve. Therefore, the life of the valve and valve seat is significantly improved. Furthermore, since an infiltration alloy such as a Pb alloy was infiltrated, wear resistance and machinability were improved.
第１図は自動車エンジンの動弁系の断面図、第２図はバ
ルブ沈み量を説明するエンジンの部分断面図である。FIG. 1 is a sectional view of a valve train of an automobile engine, and FIG. 2 is a partial sectional view of the engine for explaining the amount of valve depression.
Claims (1)
ｏの１種または２種：１．０〜２０％、ＹまたはＣｅの
１種または２種：０．２〜３％、Ａｌ：０．５〜１５％
を含有し、残部がＦｅおよび不純物元素からなる基地組
織に、ＦｅＭｏ、ＦｅＣｒ、ＦｅＷ、ＦｅＮｂまたは重
量比でＣｒ：４〜１８％、Ｖ：０．１〜０．５％、Ｍｏ
：０．２〜２％、Ｃ：０．８〜２％を含有し、残部がＦ
ｅおよび不純物元素からなるＦｅ系合金粉末から選ばれ
た１種または２種以上からなる、粒径が２０〜２００μ
ｍの硬質粒子を３〜２０重量％均一に分散させた焼結合
金に、Ｐｂ、Ｃｕ、Ｓｎまたはそれらの合金を５〜２５
重量％溶浸させたことを特徴とするバルブシート用焼結
合金。(1) Weight ratio: C: 0.4-2.0%, Ni or C
One or two types of o: 1.0 to 20%, one or two types of Y or Ce: 0.2 to 3%, Al: 0.5 to 15%
FeMo, FeCr, FeW, FeNb or weight ratio of Cr: 4 to 18%, V: 0.1 to 0.5%, Mo
: 0.2-2%, C: 0.8-2%, and the balance is F.
The particle size is 20 to 200μ, consisting of one or more selected from Fe-based alloy powders consisting of e and impurity elements.
5 to 25% of Pb, Cu, Sn or their alloys are added to the sintered alloy in which 3 to 20% by weight of hard particles of m are uniformly dispersed.
A sintered alloy for valve seats characterized by being infiltrated by weight%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6796690A JP2725430B2 (en) | 1990-03-16 | 1990-03-16 | Sintered alloy for valve seat |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6796690A JP2725430B2 (en) | 1990-03-16 | 1990-03-16 | Sintered alloy for valve seat |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03267354A true JPH03267354A (en) | 1991-11-28 |
| JP2725430B2 JP2725430B2 (en) | 1998-03-11 |
Family
ID=13360223
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6796690A Expired - Fee Related JP2725430B2 (en) | 1990-03-16 | 1990-03-16 | Sintered alloy for valve seat |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2725430B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0732417A1 (en) * | 1995-03-17 | 1996-09-18 | Toyota Jidosha Kabushiki Kaisha | A metal sintered body composite material and a method for producing the same |
| US7578866B2 (en) | 2003-03-10 | 2009-08-25 | Mitsubishi Materials Pmg Corporation | Iron-based sintered alloy having excellent machinability |
-
1990
- 1990-03-16 JP JP6796690A patent/JP2725430B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0732417A1 (en) * | 1995-03-17 | 1996-09-18 | Toyota Jidosha Kabushiki Kaisha | A metal sintered body composite material and a method for producing the same |
| US7578866B2 (en) | 2003-03-10 | 2009-08-25 | Mitsubishi Materials Pmg Corporation | Iron-based sintered alloy having excellent machinability |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2725430B2 (en) | 1998-03-11 |
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