JPH10219353A - Production of exhaust valve - Google Patents

Production of exhaust valve

Info

Publication number
JPH10219353A
JPH10219353A JP2561697A JP2561697A JPH10219353A JP H10219353 A JPH10219353 A JP H10219353A JP 2561697 A JP2561697 A JP 2561697A JP 2561697 A JP2561697 A JP 2561697A JP H10219353 A JPH10219353 A JP H10219353A
Authority
JP
Japan
Prior art keywords
weight
exhaust valve
less
umbrella
resistant steel
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
Application number
JP2561697A
Other languages
Japanese (ja)
Other versions
JP4203609B2 (en
Inventor
Toshiharu Noda
Michio Okabe
Shigenori Ueda
道生 岡部
茂紀 植田
俊治 野田
Original Assignee
Daido Steel Co Ltd
大同特殊鋼株式会社
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Daido Steel Co Ltd, 大同特殊鋼株式会社 filed Critical Daido Steel Co Ltd
Priority to JP02561697A priority Critical patent/JP4203609B2/en
Priority claimed from US08/955,753 external-priority patent/US5951789A/en
Publication of JPH10219353A publication Critical patent/JPH10219353A/en
Application granted granted Critical
Publication of JP4203609B2 publication Critical patent/JP4203609B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To provide a method for inexpensively producing an automotive exhaust valve. SOLUTION: A heat resistant steel stock contg., by weight, 0.01 to 0.1% C, <=2% Si, <=2% Mn, 12 to 25% Cr, 0.2 to 2.0% Nb+Ta, <=3.5% Ti, 0.5 to 3.0% Al, 25 to 45% Ni, 0.1 to 5.0% Cu, 0.001 to 0.01% B, and the balance Fe with inevitable impurities is subjected to solution heat treatment and is thereafter subjected to cold working or warm working to form a valve head, next, this valve head is joined with a shaft part composed of a martensitic heat resistant steel, and after that, aging treatment is executed.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【0001】[0001]
【発明の属する技術分野】本発明は排気バルブの製造方
法に関し、更に詳しくは、性能は従来のものと変わるこ
とのない排気バルブを安価に製造する方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an exhaust valve, and more particularly, to a method of manufacturing an exhaust valve at a low cost without changing its performance.
【0002】[0002]
【従来の技術】自動車エンジン用の排気バルブは、従来
から概ね次のようにして製造されている。まず、Fe−
Ni−Cr系耐熱鋼を冷間で引き抜き加工して所定寸法
の棒材を成形する。ついで、その棒材に対し例えば電気
アップセットで予備成形したのち熱間据え込みを行って
傘部を成形する。そして、この傘部に、通常はJIS
SUH−11やJIS SUH−3として規格化されて
いるマルテンサイト系耐熱鋼から成る軸部を例えば摩擦
溶接して接合一体化する。
2. Description of the Related Art Exhaust valves for automobile engines have been generally manufactured in the following manner. First, Fe-
A Ni-Cr heat-resistant steel is cold drawn to form a bar having a predetermined size. Next, the bar is preformed by, for example, an electric upset, and then hot upset to form an umbrella. And this umbrella usually has JIS
A shaft portion made of martensitic heat-resistant steel standardized as SUH-11 or JIS SUH-3 is integrally joined by, for example, friction welding.
【0003】その後、前記した加工処理によって蓄積さ
れている加工歪みを除去するために溶体化処理を行い、
ついで時効処理を行って(Ni,Cr)3(Al,Ti,
Nb,Ta)のようなγ’相を析出せしめることにより
高温強度を確保する。そして、必要により軸端の焼入れ
を行って硬化させ、最後に、機械的な仕上げ加工を行っ
て出荷される。
[0003] Thereafter, a solution treatment is performed to remove the processing strain accumulated by the above-mentioned processing,
Then, aging treatment is performed to (Ni, Cr) 3 (Al, Ti,
High temperature strength is ensured by precipitating a γ 'phase such as Nb, Ta). Then, if necessary, the shaft ends are quenched and hardened, and finally, they are mechanically finished and shipped.
【0004】[0004]
【発明が解決しようとする課題】しかしながら、上記し
た従来の製造方法には次のような問題がある。すなわ
ち、傘部の成形時には、電気アップセットで予備成形し
その後に熱間据え込みを行うという2工程を必要とする
ことである。また、成形された傘部の寸法精度はあまり
高くなく、発生した表面傷の完全な除去ということも加
味されて、仕上げ加工時における加工代は大きくなりや
すく、したがって仕上げ加工に要する時間も長くなりや
すいということである。更に、時効処理前に溶体化処理
が必要となる。
However, the above-mentioned conventional manufacturing method has the following problems. That is, when forming the umbrella portion, two steps of preforming by an electric upset and then performing hot upsetting are required. In addition, the dimensional accuracy of the molded umbrella is not very high, and taking into account the complete removal of generated surface scratches, the processing allowance at the time of finishing is likely to be large, and therefore the time required for finishing is also long. It is easy. Further, a solution treatment is required before the aging treatment.
【0005】これらの問題は、いずれも製造コストの上
昇要因であり、その解決が要求されている。上記した問
題のうちの前者の問題は、傘部の成形を熱間で行うので
はなく、例えば冷間加工または温間加工の1工程で行う
ことにより基本的には解消することができる。その場合
には、傘部用の耐熱鋼素材は冷間加工性に優れているこ
とが必要になる。
[0005] These problems are all factors that increase the manufacturing cost, and there is a demand for their solution. The former problem among the above-mentioned problems can be basically solved by performing the forming of the umbrella portion in one step of cold working or warm working, for example, instead of hot working. In that case, the heat-resistant steel material for the umbrella needs to be excellent in cold workability.
【0006】しかしながら、現在まで提案されている耐
熱鋼はいずれも熱間加工することを前提としたものであ
るため、それら素材に対して冷鍛や温鍛を行って傘部を
成形することは困難である。本発明は上記したような問
題を解決し、既に本発明者らが特願平8−301223
号や特願平8−301224号として出願した冷間加工
性に優れる耐熱鋼を排気バルブの傘部用素材とすること
により傘部の冷間加工が可能となり、従来の排気バルブ
の性能と同等な排気バルブを安価に製造する方法の提供
を目的とする。
However, since all of the heat-resistant steels proposed up to now are based on the premise that hot working is performed, it is not possible to form an umbrella portion by performing cold forging or hot forging on these materials. Have difficulty. The present invention solves the above-mentioned problems, and the present inventors have already filed Japanese Patent Application No. 8-301223.
By applying heat-resistant steel with excellent cold workability, which was filed as No. 8 or Japanese Patent Application No. 8-301224, as a material for the head part of the exhaust valve, the head part can be cold-worked, equivalent to the performance of the conventional exhaust valve. It is an object of the present invention to provide a method for manufacturing a simple exhaust valve at low cost.
【0007】[0007]
【課題を解決するための手段】上記した目的を達成する
ために、本発明においては、C:0.01〜0.1重量%,
Si:2重量%以下,Mn:2重量%以下,Cr:12
〜25重量%,Nb+Ta:0.2〜2.0重量%,Ti:
3.5重量%以下,Al:0.5〜3.0重量%,Ni:25
〜45重量%,Cu:0.1〜5.0重量%,B:0.001
〜0.01重量%,残部がFeおよび不可避的不純物から
成る耐熱鋼素材に溶体化処理を施したのち、冷間加工ま
たは温間加工を行って傘部を成形し、ついで前記傘部に
マルテンサイト系耐熱鋼から成る軸部を接合したのち時
効処理を行うことを特徴とする排気バルブの製造方法が
提供される。
In order to achieve the above object, in the present invention, C: 0.01 to 0.1% by weight,
Si: 2% by weight or less, Mn: 2% by weight or less, Cr: 12
-25% by weight, Nb + Ta: 0.2-2.0% by weight, Ti:
3.5% by weight or less, Al: 0.5 to 3.0% by weight, Ni: 25
To 45% by weight, Cu: 0.1 to 5.0% by weight, B: 0.001
To 0.01% by weight, the balance being heat-treated steel material consisting of Fe and unavoidable impurities, and then performing cold working or warm working to form an umbrella portion. A method for manufacturing an exhaust valve is provided, wherein an aging treatment is performed after joining a shaft portion made of site-based heat-resistant steel.
【0008】[0008]
【発明の実施の形態】本発明では、まず、上記した組成
の耐熱鋼素材を用いて傘部が成形される。その場合、目
的製品である排気バルブは、それがロッカーアーム式,
直動式のものであるを問わず、高温・腐食性の環境下で
稼働するので、前記した冷間加工性または温間加工性に
優れていると同時に、高温強度と耐食性にも優れている
ことが必要になる。
DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, an umbrella is first formed using a heat-resistant steel material having the above-described composition. In that case, the exhaust valve that is the target product is a rocker arm type,
Regardless of whether it is a direct acting type, it operates in a high-temperature, corrosive environment, so it has excellent cold workability or warm workability as well as high temperature strength and corrosion resistance. It becomes necessary.
【0009】この素材において、Cは、他の成分である
Nb,Ta,Tiとの間で炭化物を生成して素材の高温
強度の向上に資する成分であって、その含有量は0.01
〜0.1重量%に設定される。0.01重量%より少ない場
合は上記した炭化物の生成量は少なくなって高温強度は
低下傾向を示し、また0.1重量%より多い場合は、炭化
物が多量に析出して冷間加工性の低下や表面傷の発生が
多くなるからである。好ましくは0.01〜0.05重量%
である。
In this material, C is a component that contributes to the improvement of high-temperature strength of the material by forming carbides with other components Nb, Ta, and Ti, and its content is 0.01.
It is set to ~ 0.1% by weight. If the amount is less than 0.01% by weight, the amount of the above-mentioned carbides is reduced and the high-temperature strength tends to decrease. If the amount is more than 0.1% by weight, a large amount of carbides precipitates and the cold workability is reduced. This is because the number of occurrences of deterioration and surface flaws increase. Preferably 0.01 to 0.05% by weight
It is.
【0010】Siは脱酸剤として機能し、また素材の耐
酸化性の確保に寄与する。しかし、あまり多量に含有さ
れていると、素材の冷間加工性は低下するので、その上
限値は2重量%とする。Mnは、Siと同様に脱酸剤と
して機能する。しかし、あまり多量に含有されている
と、素材の高温下における耐酸化性が悪くなるだけでは
なく、靭性を阻害するη相(Ni3Ti)の析出を助長
するので、その含有量は2重量%以下に設定する。
[0010] Si functions as a deoxidizing agent and also contributes to securing the oxidation resistance of the material. However, if the content is too large, the cold workability of the material is reduced, so the upper limit is set to 2% by weight. Mn functions as a deoxidizing agent like Si. However, if the content is too large, not only the oxidation resistance of the material at high temperatures is deteriorated, but also the precipitation of η phase (Ni 3 Ti) which inhibits toughness is promoted. Set to less than%.
【0011】Crは高温下における耐酸化性と耐食性の
向上に資する成分であり、その含有量は12〜25重量
%に設定される。12重量%より少なくなると、上記し
た効果は発揮されず、また25重量%より多くなると、
母地のオーステナイト相が不安定となり、脆化相である
σ層が析出して素材の脆性低下を招くからである。好ま
しくは、12〜20重量%である。
[0011] Cr is a component contributing to the improvement of oxidation resistance and corrosion resistance at high temperatures, and its content is set to 12 to 25% by weight. When the amount is less than 12% by weight, the above-mentioned effects are not exhibited.
This is because the austenite phase of the base becomes unstable, and the σ layer, which is the embrittlement phase, precipitates, leading to a reduction in the brittleness of the material. Preferably, it is 12 to 20% by weight.
【0012】Nb,Taは、いずれもNiと一緒になっ
て前記したγ’相を形成して素材の高温強度の向上に資
する成分である。その合量が0.2重量%より少なくなる
と上記した効果は現れず、また合量が2.0重量%より多
くなると、δ相(Ni3(Nb,Ti))の析出が起こ
りはじめて素材の靭性低下を招く。好ましくは、0.5〜
1.5重量%である。
Nb and Ta are components that contribute to the improvement of the high-temperature strength of the material by forming the γ ′ phase together with Ni. If the total amount is less than 0.2% by weight, the above-mentioned effect is not exhibited. If the total amount is more than 2.0% by weight, precipitation of the δ phase (Ni 3 (Nb, Ti)) starts to occur, and This leads to a decrease in toughness. Preferably, 0.5 to
1.5% by weight.
【0013】Tiは、前記したようにγ’相の析出に寄
与する成分であるが、とくに後述する時効処理時にγ’
相の析出を促進する成分である。しかし、あまり多量に
含有させると、脆化相である前記したη相を析出させる
ことにより素材の靭性低下を引き起こすので、その含有
量は3.5重量%以下に設定する。好ましくは、0.5〜2.
5重量%である。
As described above, Ti is a component that contributes to the precipitation of the γ ′ phase.
It is a component that promotes phase precipitation. However, if the content is too large, the toughness of the material is reduced by precipitating the η phase, which is the embrittlement phase, so the content is set to 3.5% by weight or less. Preferably, 0.5 to 2.
5% by weight.
【0014】Alはγ’相の析出にとって必要な成分で
あり、素材の高温強度の向上に資する。その含有量が0.
5重量%より少ないと、γ’相の析出量が不充分となっ
て上記した効果の発現は少なくなり、また3.0重量%よ
り多くなると、素材の熱間加工性の低下が引き起こされ
るようになるので、その含有量は0.5〜3.0重量%に設
定される。好ましくは、0.7〜2.0重量%である。
Al is a component necessary for the precipitation of the γ 'phase, and contributes to improving the high-temperature strength of the material. Its content is 0.
If the amount is less than 5% by weight, the amount of the γ 'phase precipitated becomes insufficient and the above-mentioned effect is reduced. If the amount is more than 3.0% by weight, the hot workability of the material is reduced. Therefore, the content is set to 0.5 to 3.0% by weight. Preferably, it is 0.7 to 2.0% by weight.
【0015】Niはオーステナイト形成用の成分であ
り、素材の耐熱性と耐食性を向上せしめ、また高温下に
おいて組織を安定化せしめ、更には、強化相であるγ’
相の析出のために必須な成分であって、その含有量は2
5〜45重量%に設定される。25重量%より少ない場
合は上記した効果が充分に発揮されず、また45重量%
より多くなると、Niが高価な金属であることからして
素材のコスト上昇を招き、本発明の目的と合致しなくな
る。しかも、Ni含有量が多くなると、後述する溶体化
処理後の素材の硬さを高め、そのため、冷間加工性が低
下して、後述する冷間加工または温間加工が行いづらく
なる。好ましくは27〜35重量%である。
Ni is a component for forming austenite, improves the heat resistance and corrosion resistance of the material, stabilizes the structure at high temperatures, and furthermore, γ ′ as a strengthening phase.
Indispensable component for phase precipitation, its content is 2
It is set to 5-45% by weight. When the amount is less than 25% by weight, the above-mentioned effects are not sufficiently exerted.
If the number increases, the cost of the raw material increases because Ni is an expensive metal, and the object of the present invention is not met. In addition, when the Ni content increases, the hardness of the material after the solution treatment described later is increased, so that the cold workability is reduced and it becomes difficult to perform the cold work or the warm work described later. Preferably it is 27 to 35% by weight.
【0016】Cuは、加工硬化を抑制し、もって素材の
冷間加工性の向上に資する成分であって、その含有量は
0.1〜5.0重量%に設定される。0.1重量%より少ない
場合は上記した効果が有効に発揮されず、また5.0重量
%より多くしても、上記した効果が発揮されないだけで
はなく素材の熱間加工性の低下も引き起こされるように
なる。好ましくは0.5〜3.0重量%である。
Cu is a component that suppresses work hardening and thus contributes to improving the cold workability of a material.
It is set to 0.1 to 5.0% by weight. When the amount is less than 0.1% by weight, the above-mentioned effects are not effectively exhibited. When the amount is more than 5.0% by weight, not only the above-mentioned effects are not exhibited, but also the hot workability of the material is lowered. Will be able to Preferably it is 0.5 to 3.0% by weight.
【0017】Bは結晶粒界に偏析して粒界強度の向上に
資する成分で、その含有量は0.001〜0.01重量%に
設定される。0.001重量%より少ない場合は上記効果
が充分に発揮されず、また0.01重量%より多くなると
素材の熱間加工性が低下するようになる。本発明で用い
る耐熱鋼素材には、更にP,S,O,Nなどの不可避的
不純物が含有されているが、これら不可避的不純物は、
いずれも、他の成分との間で非金属介在物を生成して素
材の機械的強度の低下を引き起こす要因になるので、そ
の含有量は0.01重量%に制限されることが好ましい。
B is a component that segregates at the crystal grain boundaries and contributes to the improvement of the grain boundary strength, and its content is set to 0.001 to 0.01% by weight. When the amount is less than 0.001% by weight, the above effect is not sufficiently exhibited. When the amount is more than 0.01% by weight, the hot workability of the material is reduced. The heat-resistant steel material used in the present invention further contains unavoidable impurities such as P, S, O, and N.
In any case, the content is preferably limited to 0.01% by weight, since nonmetallic inclusions are generated with other components to cause a decrease in mechanical strength of the material.
【0018】この素材は、上記した組成を必須とする
が、更に必要に応じては、W:3重量%以下,Mo:3
重量%以下,V:1重量%以下,Co:5重量%以下,
Ca+Mg:0.001〜0.01重量%,Zr:0.001
〜0.01重量%を含有していてもよい。その場合、W,
Mo,Vはいずれも溶体化処理後における素材の高温強
度の向上に資する成分である。これらの成分の含有量を
あまり多くしても、上記した効果は飽和状態に達するだ
けではなく、素材のコスト上昇,冷間加工性の低下を招
くようになるので、それらの含有量は上記した値を上限
値とする。
This material must have the above-mentioned composition, but if necessary, W: 3% by weight or less, Mo: 3
% By weight, V: 1% by weight or less, Co: 5% by weight or less,
Ca + Mg: 0.001 to 0.01% by weight, Zr: 0.001
To 0.01% by weight. In that case, W,
Both Mo and V are components that contribute to improving the high-temperature strength of the material after the solution treatment. Even if the content of these components is too large, the above-mentioned effects not only reach the saturated state, but also increase the cost of the material and decrease the cold workability. The value is the upper limit.
【0019】Coは、Niと略同じ作用を示す成分であ
って、Niの一部を置換する状態で含有させることがで
きる。しかしながら、CoはNiに比べても高価な金属
であるため、多量に含有させると素材のコスト上昇を招
くので、その含有量は上記した値を上限にする。Ca,
Mgは、いずれも、素材を溶製するときに、脱酸剤およ
び脱硫剤として機能する成分であり、脱酸,脱硫効果を
発揮させるためには0.001重量%以上を必要とする
が、あまり多く含有させると素材の熱間加工性の低下が
引き起こされるので0.01重量%以下に制限することが
好ましい。
Co is a component having substantially the same effect as Ni, and can be contained in a state where Ni is partially substituted. However, since Co is a more expensive metal than Ni, if it is contained in a large amount, the cost of the material will increase. Therefore, the content is limited to the above value. Ca,
Mg is a component that functions as a deoxidizing agent and a desulfurizing agent at the time of melting the material, and requires 0.001% by weight or more to exhibit the deoxidizing and desulfurizing effects. If the content is too large, the hot workability of the raw material is reduced. Therefore, the content is preferably limited to 0.01% by weight or less.
【0020】また、ZrはBと同じように粒界強度の向
上に資する成分であり、Bの場合と同じように、その含
有量は0.001〜0.01重量%の範囲内にすることが好
ましい。本発明は次のようにして実施される。最初に、
上記した組成の耐熱鋼を素材として、以下の手順で傘部
が成形される。
Zr is a component contributing to the improvement of the grain boundary strength in the same manner as B, and the content thereof is in the range of 0.001 to 0.01% by weight as in the case of B. Is preferred. The present invention is implemented as follows. At first,
Using the heat-resistant steel having the above-described composition as a material, an umbrella portion is formed in the following procedure.
【0021】すなわち、まず、素材に均熱処理を施した
のち、熱間で鍛伸および圧延を行って所定形状の棒材に
する。ついで、この棒材に溶体化処理を行う。具体的に
は、棒材を1000〜1100℃の温度域で10〜60
分間程度保持したのち、水または油を用いて急冷する。
That is, first, after a soaking treatment is applied to the material, hot forging and rolling are performed to obtain a bar having a predetermined shape. Next, the rod is subjected to a solution treatment. Specifically, the rod is heated at a temperature of 1000 to 1100 ° C. for 10 to 60 hours.
After holding for about a minute, quench using water or oil.
【0022】この溶体化処理により、Cr炭化物や、前
記したγ’相,脆化相であるη相は固溶し、再結晶によ
る軟化がすすみ、また前記した鍛伸および圧延で蓄積さ
れた内部応力が除去され、棒材は全体として軟化する。
傘部を成形するに際しては、上記した溶体化処理後の棒
材が出発の素材となる。
As a result of the solution treatment, the Cr carbide and the γ ′ phase and the η phase, which is the embrittlement phase, form a solid solution and soften by recrystallization, and the internal state accumulated by the forging and rolling described above. The stress is removed and the bar softens as a whole.
When forming the umbrella, the rod material after the above solution treatment is the starting material.
【0023】すなわち、上記棒材に対し、直接、冷間加
工または間鍛加工が施されることにより、目的とする形
状の傘部が成形される。棒材は既に溶体化処理されて軟
質になっているので、この冷間による据え込み加工は円
滑に行うことができる。そして、成形された傘部の寸法
精度は高くなるため、最後の仕上げ加工時における加工
代が少なくなる。また、冷間加工または温間加工である
ため、傘部の形成に要する費用は熱間加工の場合に比べ
て節約される。
That is, the bar is directly subjected to cold working or cold forging, whereby an umbrella portion having a desired shape is formed. Since the rod has already been softened by the solution treatment, the cold upsetting can be performed smoothly. Since the dimensional accuracy of the formed umbrella part is high, the processing allowance at the time of the final finishing processing is reduced. Further, since the cold working or the warm working is performed, the cost required for forming the umbrella portion is reduced as compared with the case of the hot working.
【0024】ついで、上記傘部に、例えばJIS SU
H−11やJIS SUH−3のような低温焼きなまし
をしたマルテンサイト系耐熱鋼から成る軸部が例えば摩
擦接合されて目的形状の排気バルブが成形される。そし
て、本発明においては、成形された排気バルブに対し、
従来のように溶体化処理を施すことなく、直ちに、例え
ば650〜800℃の温度域で0.5時間程度の高温時効
処理が行われる。
Next, for example, JIS SU
A shaft portion made of martensitic heat-resistant steel annealed at a low temperature such as H-11 or JIS SUH-3 is friction-joined, for example, to form an exhaust valve having a desired shape. And in the present invention, for the formed exhaust valve,
A high-temperature aging treatment is performed immediately in a temperature range of, for example, 650 to 800 ° C. for about 0.5 hours without performing a solution treatment as in the related art.
【0025】この時効処理により、前記した冷間加工時
の残留歪みで加工硬化していることに加えて、更に傘部
ではγ’相の析出が進んでHV350〜500程度にま
で硬化する。また、硬化した接合部では、マルテンサイ
トの焼戻しが起こってHVは250〜350程度にまで
低下し、かつ靭性は向上する。そして最後に、仕上げ加
工を行って、目的とする排気バルブが製造される。
By this aging treatment, in addition to the work hardening due to the residual strain during the cold working described above, the precipitation of the γ 'phase further proceeds in the umbrella part, and the HV hardens to about 350 to 500 HV. Further, in the hardened joint portion, tempering of martensite occurs, HV is reduced to about 250 to 350, and toughness is improved. Finally, finishing processing is performed to manufacture a target exhaust valve.
【0026】なお、本発明においては、上記した仕上げ
加工に続けて、軸部に窒化処理を行って当該軸部に窒化
層を形成すると、耐摩耗性が向上するので好適である。
窒化処理の方法としては格別限定されるものではない
が、靭性に富みかつ耐摩耗性が優れた極めて薄い窒化層
を形成できるという点で、タフトライド法に代表される
液体窒化法を適用することが好ましい。
In the present invention, it is preferable to perform a nitriding treatment on the shaft portion to form a nitrided layer on the shaft portion after the above-mentioned finishing work, because the wear resistance is improved.
Although the method of the nitriding treatment is not particularly limited, it is possible to apply a liquid nitriding method represented by a tuftride method in that an extremely thin nitride layer having high toughness and excellent wear resistance can be formed. preferable.
【0027】また、排気バルブがロッカーアーム式のも
のである場合には、更に軸端部に対して焼入れ硬化を行
うと、当該軸端部の摩耗防止にとって有効である。焼入
れの方法としては、例えば、高周波焼入れ,フレーム焼
入れなどを適用することができる。
When the exhaust valve is of a rocker arm type, quenching and hardening the shaft end is effective for preventing the shaft end from being worn. As a quenching method, for example, induction hardening, frame quenching, or the like can be applied.
【0028】[0028]
【実施例】【Example】
実施例1〜3,従来例 真空誘導炉で表1に示した組成の鋼を50kg溶製したの
ちインゴットを製造した。
Examples 1 to 3 and Conventional Example An ingot was manufactured after melting 50 kg of steel having the composition shown in Table 1 in a vacuum induction furnace.
【0029】[0029]
【表1】 [Table 1]
【0030】これら7種類のインゴットに1100℃で
16時間の均熱処理を行ったのち、直径70mmに鍛伸
し、更に直径16mmの丸棒に圧延した。ついで、これら
の丸棒を、温度1050℃で30分間保持したのち油冷
して溶体化処理を行い、傘部の素材とした。これらの素
材を用いて、以下の態様で排気バルブを製造した。
The seven types of ingots were subjected to a soaking process at 1100 ° C. for 16 hours, then forged to a diameter of 70 mm, and further rolled into a round bar having a diameter of 16 mm. Next, these round bars were maintained at a temperature of 1050 ° C. for 30 minutes, and then cooled with oil to perform a solution treatment to obtain a material for an umbrella portion. Using these materials, exhaust valves were manufactured in the following manner.
【0031】1)各素材室温下で冷間加工して傘径が24.
3mmの傘部を成形し、それに、JIS SUH−11か
ら成り、直径が5.8mmの軸部を摩擦接合した。ついで、
温度750℃で4時間保持したのち空冷する時効処理を
おこなったのち仕上げ加工し、更に、温度570℃で3
0分間のタフトライド処理を施して7種類の排気バルブ
を製造した。この排気バルブは直動式の動弁系に使用す
ることを目的とする。これを実施例1とする。
1) Each material is cold worked at room temperature and the umbrella diameter is 24.
A 3 mm umbrella was molded, and a shaft made of JIS SUH-11 and having a diameter of 5.8 mm was friction-bonded thereto. Then
After holding at a temperature of 750 ° C. for 4 hours, performing an aging treatment of air cooling, finishing, and further finishing at a temperature of 570 ° C. for 3 hours.
Seven types of exhaust valves were produced by performing a 0 minute tuftride treatment. This exhaust valve is intended to be used for a direct-acting valve train. This is referred to as Example 1.
【0032】2)各素材を温度500℃で温間加工して傘
部を成形したことを除いては、実施例1と同様にして排
気バルブを製造した。この排気バルブもまた直動式動弁
系への使用が目的とされている。これを実施例2とす
る。 3)実施例1で製造した排気バルブの軸端部に、高周波を
用い、温度1050℃で30秒間加熱したのち空冷を行
った。
2) An exhaust valve was manufactured in the same manner as in Example 1 except that each material was warm-worked at a temperature of 500 ° C. to form an umbrella. This exhaust valve is also intended for use in a direct acting valve train. This is Example 2. 3) The shaft end of the exhaust valve manufactured in Example 1 was heated at a temperature of 1050 ° C. for 30 seconds using high frequency and then air-cooled.
【0033】この排気バルブは、ロッカーアーム式の動
弁系に使用することを目的としている。これを実施例3
とする。 4)各素材を通電アップセット法で予備成形したのち熱間
で据え込み加工して傘径24.3mmの傘部を成形し、これ
にJIS SUH−11から成る軸部(直径5.8mm)を
摩擦接合した。
This exhaust valve is intended to be used for a rocker arm type valve train. Example 3
And 4) Each material is preformed by the energization upset method, and then hot-set up to form an umbrella portion with an umbrella diameter of 24.3 mm. The shaft portion (diameter of 5.8 mm) made of JIS SUH-11 Was friction bonded.
【0034】ついで、温度1050℃で30分間保持し
たのち油冷して溶体化処理を行い、更に続けて、温度7
50℃で4時間保持したのち空冷して時効処理を行っ
た。その後、仕上げ加工を行い、更に温度570度で3
0分間のタフトライド処理を行い、ついで軸端部を、高
周波を用い、1050℃で30秒間加熱したのち空冷を
行ってロッカーアーム式動弁系に使用する排気バルブを
製造した。これを従来例とする。
Then, the mixture was kept at a temperature of 1050 ° C. for 30 minutes, cooled with oil, and subjected to a solution treatment.
After maintaining at 50 ° C. for 4 hours, the mixture was air-cooled and subjected to an aging treatment. After that, finish processing is performed.
The shaft end was heated at 1050 ° C. for 30 seconds using high frequency and then air-cooled to produce an exhaust valve used for a rocker arm type valve train. This is a conventional example.
【0035】上記した態様で製造した各排気バルブのフ
ェース面の硬度を測定した。また、従来例による製造コ
ストと実施例1,2,3による製造コストを比較した。
それらの結果を、表1で示した各素材に対比させて表2
に示した。
The hardness of the face surface of each of the exhaust valves manufactured as described above was measured. Further, the manufacturing cost according to the conventional example and the manufacturing cost according to Examples 1, 2, and 3 were compared.
The results are shown in Table 2 in comparison with each material shown in Table 1.
It was shown to.
【0036】[0036]
【表2】 [Table 2]
【0037】本発明方法で製造した排気バルブのフェー
ス面は、従来方法で製造した排気バルブのフェース面よ
りも硬くなっている。そこで、試料No.1〜3の素材を
用いて、実施例1の方法と従来例の方法で製造した直動
式動弁系の排気バルブを実機に組み込んで6000rp
m,100時間の耐久試験を行い、傘部と首部の損傷状
態を観察した。このときの使用温度は約800℃であっ
た。
The face of the exhaust valve manufactured by the method of the present invention is harder than the face of the exhaust valve manufactured by the conventional method. Therefore, using the materials of Sample Nos. 1 to 3, the exhaust valve of the direct-acting type valve train manufactured by the method of Example 1 and the method of the conventional example was incorporated in an actual machine to 6000 rp.
The endurance test was performed for 100 hours at m, and the umbrella and the neck were observed for damage. The working temperature at this time was about 800 ° C.
【0038】両者ともに損傷は認められなかった。ま
た、耐久試験の終了後、本発明方法で製造した排気バル
ブを取り外し、そのフェース面の硬さを測定したとこ
ろ、HVは280〜350であり、従来の場合と同等の
硬さになっていた。
No damage was observed in either case. After the endurance test, the exhaust valve manufactured by the method of the present invention was removed, and the hardness of the face surface was measured. The HV was 280 to 350, which was equivalent to the hardness of the conventional case. .
【0039】[0039]
【発明の効果】以上の説明で明らかなように、本発明方
法で製造した排気バルブは、実機試験において、従来方
法で製造した排気バルブと同等の性能を発揮する。そし
て、傘部の成形を冷間加工または温間加工で行うので、
従来に比べて成形コストは低減し、しかも寸法精度が高
くなって仕上げ加工時の加工代は少なくなり、全体とし
ての製造コストは低減する。
As apparent from the above description, the exhaust valve manufactured by the method of the present invention exhibits the same performance as the exhaust valve manufactured by the conventional method in an actual machine test. And since the umbrella is formed by cold working or warm working,
The molding cost is reduced as compared with the related art, and the dimensional accuracy is increased, so that the processing cost at the time of finishing is reduced, and the overall manufacturing cost is reduced.
【0040】すなわち、本発明は、従来と性能的に同等
な排気バルブを安価に製造することができるので、その
工業的価値は大である。
That is, according to the present invention, an exhaust valve equivalent in performance to a conventional exhaust valve can be manufactured at low cost, and therefore, its industrial value is great.

Claims (4)

    【特許請求の範囲】[Claims]
  1. 【請求項1】 C:0.01〜0.1重量%,Si:2重量
    %以下,Mn:2重量%以下,Cr:12〜25重量
    %,Nb+Ta:0.2〜2.0重量%,Ti:3.5重量%
    以下,Al:0.5〜3.0重量%,Ni:25〜45重量
    %,Cu:0.1〜5.0重量%,B:0.001〜0.01重
    量%,残部がFeおよび不可避的不純物から成る耐熱鋼
    素材に溶体化処理を施したのち、冷間加工または温間加
    工を行って傘部を成形し、ついで前記傘部にマルテンサ
    イト系耐熱鋼から成る軸部を接合したのち時効処理を行
    うことを特徴とする排気バルブの製造方法。
    1. C: 0.01 to 0.1% by weight, Si: 2% by weight or less, Mn: 2% by weight or less, Cr: 12 to 25% by weight, Nb + Ta: 0.2 to 2.0% by weight , Ti: 3.5% by weight
    Hereinafter, Al: 0.5 to 3.0% by weight, Ni: 25 to 45% by weight, Cu: 0.1 to 5.0% by weight, B: 0.001 to 0.01% by weight, the balance being Fe and After subjecting the heat-resistant steel material composed of unavoidable impurities to a solution treatment, cold working or warm working was performed to form an umbrella portion, and then a shaft portion made of martensitic heat-resistant steel was joined to the umbrella portion. A method for manufacturing an exhaust valve, comprising performing aging treatment afterwards.
  2. 【請求項2】 前記耐熱鋼素材には、更に、W:3重量
    %以下,Mo:3重量%以下,V:1重量%以下,C
    o:5重量%以下,Ca+Mg:0.001〜0.01重量
    %,Zr:0.001〜0.01重量%が含有されている請
    求項1の排気バルブの製造方法。
    2. The heat-resistant steel material further comprises: W: 3% by weight or less, Mo: 3% by weight or less, V: 1% by weight or less,
    2. The method for manufacturing an exhaust valve according to claim 1, wherein o: 5% by weight or less, Ca + Mg: 0.001 to 0.01% by weight, and Zr: 0.001 to 0.01% by weight.
  3. 【請求項3】 前記時効処理後に、窒化処理を行う請求
    項1または2の排気バルブの製造方法。
    3. The method according to claim 1, wherein a nitriding treatment is performed after the aging treatment.
  4. 【請求項4】 前記窒化処理後に、前記軸部の端部に焼
    入れ処理を行う請求項1〜3のいずれかの排気バルブの
    製造方法。
    4. The method for manufacturing an exhaust valve according to claim 1, wherein a quenching process is performed on an end of the shaft portion after the nitriding process.
JP02561697A 1997-02-07 1997-02-07 Exhaust valve manufacturing method Expired - Fee Related JP4203609B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP02561697A JP4203609B2 (en) 1997-02-07 1997-02-07 Exhaust valve manufacturing method

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP02561697A JP4203609B2 (en) 1997-02-07 1997-02-07 Exhaust valve manufacturing method
US08/955,753 US5951789A (en) 1996-10-25 1997-10-22 Heat resisting alloy for exhaust valve and method for producing the exhaust valve
EP97118341A EP0838533B1 (en) 1996-10-25 1997-10-22 Heat resisting alloy for exhaust valve and method for producing the exhaust valve
DE1997610409 DE69710409T2 (en) 1996-10-25 1997-10-22 Heat resistant alloy for exhaust valves and method of manufacturing such exhaust valves
US09/114,494 US6099668A (en) 1996-10-25 1998-07-13 Heat resisting alloy for exhaust valve and method for producing the exhaust valve

Publications (2)

Publication Number Publication Date
JPH10219353A true JPH10219353A (en) 1998-08-18
JP4203609B2 JP4203609B2 (en) 2009-01-07

Family

ID=12170829

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
JP (1) JP4203609B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1464718A1 (en) * 2003-03-18 2004-10-06 HONDA MOTOR CO., Ltd. High-strength, heat-resistant alloy for exhaust valves with improved overaging-resistance
JP2012225203A (en) * 2011-04-18 2012-11-15 Nippon Parkerizing Co Ltd Highly durable engine valve
JP2015121228A (en) * 2014-12-25 2015-07-02 日本パーカライジング株式会社 High durability engine valve

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1464718A1 (en) * 2003-03-18 2004-10-06 HONDA MOTOR CO., Ltd. High-strength, heat-resistant alloy for exhaust valves with improved overaging-resistance
JP2012225203A (en) * 2011-04-18 2012-11-15 Nippon Parkerizing Co Ltd Highly durable engine valve
JP2015121228A (en) * 2014-12-25 2015-07-02 日本パーカライジング株式会社 High durability engine valve

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