JPH07109539A - Fe-ni-cr-based superalloy, engine valve and knit mesh for exhaust gas catalyst - Google Patents

Abstract

PURPOSE:To produce an Fe-Ni-based superalloy with resource economization excellent in high temp. strength after long time heating and cold ductility, having sufficient oxidation resistance and suitable for an engine valve and a knit mesh material for an exhaust gas catalyst. CONSTITUTION:This Fe-Ni-Cr-based superalloy is the one contg., by weight, <=0.15% C, <=1.0% Si, <=3.0% Mn, 30 to 49% Ni, 10 to 18% Cr and 1.6 to 3.0% Al, contg. total 1.5 to 8.0% of one or >= two kinds of elements selected from the groups IVa and Va, and the balance substantial Fe with impurities, and if required, Mo, W, Co, B, Mg, Ca, Y and rare earth metals may be added in specified ranges.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は高温強度に優れた安価な
Ｆｅ−Ｎｉ−Ｃｒ基超耐熱合金と、この合金を用いて製
造される自動車用エンジンバルブおよび自動車用排ガス
触媒用ニットメッシュに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inexpensive Fe-Ni-Cr-based superheat-resistant alloy having excellent high-temperature strength, and an engine valve for automobiles and a knit mesh for exhaust gas catalysts for automobiles produced by using this alloy. Is.

【０００２】[0002]

【従来の技術】近年、地球的規模の環境汚染問題に対
し、従来にもまして、省エネルギー化、排気ガスの清浄
化が求められているとともに一方では、部品の省資源化
が望まれている。このような目的に対し、自動車等の内
燃機関においてもっとも高温で高い応力下に曝されるエ
ンジンバルブ材や排気ガスメッシュ材などの高品質部材
の省資源化が強く待ち望まれている。2. Description of the Related Art In recent years, energy saving and exhaust gas cleaning have been demanded more than ever in response to global-scale environmental pollution problems, while resource saving of parts has been desired. For such a purpose, resource saving of high quality members such as engine valve materials and exhaust gas mesh materials exposed to the highest temperature and high stress in internal combustion engines such as automobiles has been strongly desired.

【０００３】従来、ガソリンエンジンやディーゼルエン
ジンの排気バルブ用材料としては、高Ｍｎ系のオーステ
ナイト鋼であるＳＵＨ３５（Ｆｅ−８．５Ｍｎ−２１Ｃ
ｒ−４Ｎｉ−０．５Ｃ−０．４Ｎ）が広く使用されてき
たが、一部使用温度の高温化に伴ってＮｉ基超耐熱合金
であるＮＣＦ７５１（Ｎｉ−１５．５Ｃｒ−１Ｎｂ−
２．３Ｔｉ−１．２Ａｌ−７Ｆｅ）が用いられるように
なってきた。しかし、ＮＣＦ７５１はＮｉを約７０％も
含むためにＳＵＨ３５に比べて非常に高価である。そこ
で、ＮＣＦ７５１よりも省資源で、かつできるだけＮＣ
Ｆ７５１に近い高温強度と長時間加熱後の組織安定性を
有する合金開発が行なわれてきた。その結果、例えば特
公平１−１２８２７号、特開昭６２−２１４１４９号、
特開昭５８−１８９３５９号、特開昭６３−２１３６３
１号、特開昭６１−２３８９４２号、特公昭６２−５０
５４２号、特公平４−１１６１３号、特開昭６０−２１
１０２８号等多くの提案がある。Conventionally, SUH35 (Fe-8.5Mn-21C), which is a high Mn austenitic steel, has been used as a material for exhaust valves of gasoline engines and diesel engines.
r-4Ni-0.5C-0.4N) has been widely used, but NCF751 (Ni-15.5Cr-1Nb-), which is a Ni-base super heat-resistant alloy, has been used due to the increase in the operating temperature.
2.3Ti-1.2Al-7Fe) has come into use. However, since NCF751 contains about 70% of Ni, it is much more expensive than SUH35. Therefore, it is more resource-saving than NCF751 and NC as much as possible.
Alloys having high-temperature strength close to that of F751 and structural stability after long-term heating have been developed. As a result, for example, Japanese Examined Patent Publication No. 1-182727, JP-A-62-214149,
JP-A-58-189359 and JP-A-63-21363
No. 1, JP-A-61-238942, JP-B-62-50
No. 542, Japanese Examined Patent Publication No. 4-11613, JP-A-60-21.
There are many proposals such as No. 1028.

【０００４】[0004]

【発明が解決しようとする課題】近年の自動車エンジン
用ガソリン燃料は、排ガスの清浄化要求に対して、無鉛
化対策が進められるようになり、無鉛ガソリン専用エン
ジンが主流となりつつある。自動車エンジンバルブや排
ガス触媒用ニットメッシュ材のようにエンジン部品のな
かでも特に高温で使用される部材にとっては、無鉛化は
腐食環境の改善につながり、ＮＣＦ７５１と同レベルの
耐酸化性さえ有すればよく、従来問題とされていた酸化
鉛に対する耐食性は、考慮せずともよくなった。一方
で、自動車の保証期間の延長に伴って、耐久性に関して
は性能改善が要求されるようになり、高温長時間使用後
の材料の強度低下ならびに脆化が極力少ない合金が要求
されるようになってきた。With respect to gasoline fuel for automobile engines in recent years, lead-free measures have been taken in response to exhaust gas cleaning requirements, and unleaded gasoline-only engines are becoming mainstream. For engine parts such as automobile engine valves and knit mesh materials for exhaust gas catalysts, which are used especially at high temperatures, lead-free improves the corrosive environment, as long as it has the same level of oxidation resistance as NCF751. Well, the corrosion resistance to lead oxide, which has been a problem in the past, was improved without considering it. On the other hand, with the extension of the warranty period of automobiles, performance improvement is required in terms of durability, and there is a demand for alloys with minimal strength deterioration and brittleness after long-term use at high temperature. It's coming.

【０００５】ＮＣＦ７５１の省資源材のうち、特開昭６
３−２１３６３１号、特公平４−１１６１３号および特
開昭６０−２１１０２８号で提案される合金は、ＮＣＦ
７５１に近い高温強度と長時間組織安定性が得られる
が、Ｎｉ含有量が５０％を超えるために、ＮＣＦ７５１
よりも十分に省資源化と低価格化が計れていない。ま
た、特公平１−１２８２７号、特開昭６２−２１４１４
９号、および特開昭５８−１８９３５９号で提案される
合金は、Ｃｒ含有量が高いために耐酸化性・耐食性には
優れるがＣｒに富んだσ相やα’相等の常温の延性を劣
化させる異相が析出する。一方、特開昭６１−２３８９
４２号および特公昭６２−５０５４２号で提案される合
金は、低Ｎｉ、低Ａｌの合金組成のため、長時間加熱時
に析出強化相であるγ’（ガンマプライム）相の粗大化
や、γ’相からη（イータ）相への変態が生じて長時間
加熱後の高温強度の低下量が大きくなる。Of the NCF751 resource-saving materials, Japanese Patent Laid-Open No.
The alloys proposed in JP-A-3-213163, JP-B-4-11613 and JP-A-60-211028 are NCF.
Although high temperature strength close to that of 751 and long-term microstructure stability can be obtained, since the Ni content exceeds 50%, NCF751
Resource saving and price reduction have not been achieved. Also, Japanese Examined Patent Publication No. 1-182727 and JP-A-62-21414.
The alloys proposed in No. 9 and JP-A No. 58-189359 are excellent in oxidation resistance and corrosion resistance because of high Cr content, but deteriorate in ductility at room temperature such as σ phase and α'phase rich in Cr. The heterogeneous phase is deposited. On the other hand, JP-A-61-2389
The alloys proposed in Japanese Patent No. 42 and Japanese Patent Publication No. 62-50542 have low Ni and low Al alloy compositions, so that the γ ′ (gamma prime) phase, which is a precipitation strengthening phase, becomes coarse during long-term heating, and γ ′. The transformation from the phase to the η (eta) phase occurs, and the amount of decrease in high temperature strength after heating for a long time becomes large.

【０００６】本発明の目的は、これら上記の従来合金が
達成し得なかった長時間加熱後の高温強度と常温延性に
優れ、併せて十分な耐酸化性を有する省資源のＦｅ−Ｎ
ｉ−Ｃｒ基超耐熱合金を提供すること、さらにはこの合
金を用いて製造されるエンジンバルブおよび排ガス触媒
用ニットメッシュを提供することにある。The object of the present invention is to save resource-saving Fe-N which is excellent in high temperature strength after long-time heating and room temperature ductility, which are not achieved by the above-mentioned conventional alloys, and also has sufficient oxidation resistance.
An object of the present invention is to provide an i-Cr-based superheat-resistant alloy, and further to provide an engine valve and an exhaust gas catalyst knit mesh manufactured using this alloy.

【０００７】[0007]

【課題を解決するための手段】このような材料劣化を予
測する手段として、本研究では８００℃にて４００時間
加熱した試料を作製し、８００℃での引張強度ならびに
回転曲げ疲労強度を測定することにより、合金の長時間
加熱後の高温強度を測定した。一方でこの試料の常温(2
0℃)Ｕノッチシャルピー衝撃試験を実施し、その衝撃値
から材料の靭性を評価した。さらに耐酸化性について
は、８５０℃にて４００時間加熱後の重量変化を測定し
た。[Means for Solving the Problems] As a means for predicting such material deterioration, in this study, a sample heated at 800 ° C. for 400 hours is prepared, and tensile strength and rotational bending fatigue strength at 800 ° C. are measured. Thus, the high temperature strength of the alloy after heating for a long time was measured. On the other hand, the room temperature (2
(0 ° C.) U-notch Charpy impact test was performed, and the toughness of the material was evaluated from the impact value. Further, regarding the oxidation resistance, the weight change after heating at 850 ° C. for 400 hours was measured.

【０００８】これらの評価結果から、以下に示す３つの
手法を用いることにより、省資源のために５０％を超え
ないＮｉ量で、かつ目的を満足する合金を新規に発明す
るに至った。 (1) Ni₃(Al,IVa,Va)からなるγ’相において、原子％
で表される1.8[Al]/([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[T
a])の量を高めることにより、γ’相を安定化させた
（これは、Ａｌ量単独の増加にもつながる）。この考え
に基づき、Ａｌ量を重量％で１．６〜３．０％とし、さ
らに原子％で表される[Al]/([Al]+[Ti]+[Zr]+[Hf]+[V]+
[Nb]+[Ta])量比を０．４５〜０．７５の範囲とすること
で、従来のFe-Ni-Cr基合金で問題となっていた長時間加
熱時のγ’相からη相やδ相への変態による高温強度の
低下を防ぐことができた。また、このＡｌ量の増量は、
高温加熱時にAl₂O₃の生成量を増し、(3)のＣｒ量の低下
による耐酸化性の低下を補完する働きももつ。５０％を
下回るＮｉ量と２０％以下のＣｒ量を含有するFe-Ni-Cr
基超耐熱合金において、このような高Ａｌと高1.8[Al]/
([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])量を有する従来
合金はなく、まったく新規の発明である。From these evaluation results, by using the following three methods, a new alloy having a Ni content not exceeding 50% and satisfying the purpose was newly invented in order to save resources. (1) In the γ'phase composed of Ni ₃ (Al, IVa, Va), atomic%
1.8 [Al] / ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [T
The [gamma] 'phase was stabilized by increasing the amount of a]) (this also leads to an increase in the amount of Al alone). Based on this idea, the amount of Al is set to 1.6 to 3.0% by weight, and further represented by atomic% [Al] / ([Al] + [Ti] + [Zr] + [Hf] + [ V] +
By setting the [Nb] + [Ta]) amount ratio in the range of 0.45 to 0.75, it is possible to obtain η from the γ'phase during long-time heating, which has been a problem with conventional Fe-Ni-Cr-based alloys. It was possible to prevent the decrease in high temperature strength due to the transformation to the δ phase or the δ phase. In addition, the increase in the amount of Al is
It also has the function of increasing the amount of Al ₂ O ₃ produced during high-temperature heating and complementing the reduction in oxidation resistance due to the reduction in the amount of Cr in (3). Fe-Ni-Cr containing less than 50% Ni and less than 20% Cr
In a base super heat-resistant alloy, such high Al and high 1.8 [Al] /
There is no conventional alloy having an amount of ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta]), which is a completely new invention.

【０００９】(2) マトリックスのＮｉ量低下による高温
強度の低下をγ’相の増量で補う。これらは従来合金と
一部重複するＩＶａ族およびＶａ族の添加量に加え、さ
らに高いAl量を添加することで達成された。さらに詳細
には、目的とする強度を得るためのγ’量は原子％で表
される([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])の量と相
関があり、この値を従来の鍛造合金よりも高い６．５〜
１０．０の範囲に管理することで、短時間高温強度の向
上が可能になった（この量の４倍が計算γ’量とな
る）。このように高い計算γ’量がエンジンバルブ用な
どの鍛造合金で、実用化されたことはなく、この点も全
く新規の発明である。Ｎｉ量が５０％以上のＮｉ基超耐
熱合金の場合、γ’相が高温まで安定となりこのレベル
のγ’量では熱間加工が困難となる。また、(1)で示し
た[Al]/([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])量が低い
合金の場合も,ＩＶａ族およびＶａ族の固溶強化とγ’
相の格子ひずみ量の増加によって、熱間加工が困難とな
る。よって、このような高い計算γ’量はＮｉ量が５０
％を超えず、かつ(1)で示した[Al]/([Al]+[Ti]+[Zr]+[H
f]+[V]+[Nb]+[Ta])量が高い場合のみ加工できることを
見出した。(2) The decrease in high temperature strength due to the decrease in the Ni content of the matrix is compensated by the increase in the γ'phase. These have been achieved by adding a higher Al amount in addition to the IVa and Va group addition amounts that partially overlap with the conventional alloy. More specifically, the amount of γ'for obtaining the desired strength is expressed in atomic% ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta ]), Which is higher than that of conventional forged alloys.
By controlling the range to 10.0, it became possible to improve the high-temperature strength for a short time (four times this amount becomes the calculated γ ′ amount). Such a high calculated γ ′ amount has never been put to practical use in a forged alloy for engine valves or the like, and this is also a completely new invention. In the case of a Ni-based superheat-resistant alloy having a Ni content of 50% or more, the γ'phase is stable up to high temperatures, and hot working becomes difficult at this level of the γ'content. In addition, in the case of the alloy with a low [Al] / ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta]) amount shown in (1), IVa Solution Strengthening of Group III and Va and γ '
Due to the increase in the amount of lattice strain of the phase, hot working becomes difficult. Therefore, such a high calculated γ ′ amount has a Ni amount of 50
%, And [Al] / ([Al] + [Ti] + [Zr] + [H] shown in (1)
It was found that processing can be performed only when the amount of [f] + [V] + [Nb] + [Ta]) is high.

【００１０】(3) 長時間加熱後にもσ相やα’相などの
Ｃｒに富んだ脆化相が析出しないようマトリックスのＣ
ｒ量を耐酸化性を劣化させない最小限の添加に留める。
さらに、Ｃｒと同族の元素であるＭｏとＷの添加量につ
いても必要に応じて、重量％を原子％に換算した場合の
総和で定めた。上記(1),(2)とこのＣｒ量の最適化もま
ったく新規の組み合わせであり、これらを同時に実施す
ることにより目的とする長時間加熱後の強度と延性を兼
備する合金を得ることができた。(3) C of the matrix is prevented so that the Cr-rich embrittlement phases such as σ phase and α'phase do not precipitate even after heating for a long time.
The amount of r is limited to the minimum amount that does not deteriorate the oxidation resistance.
Furthermore, the addition amounts of Mo and W, which are elements in the same family as Cr, were also determined by the total when the weight% was converted into atomic%, if necessary. The above (1) and (2) and the optimization of this Cr content are completely new combinations, and by carrying out them at the same time, it is possible to obtain an alloy having both strength and ductility after long-term heating. It was

【００１１】すなわち、本発明は重量％でＣ０．１５％
以下，Ｓｉ１．０％以下，Ｍｎ３．０％以下，Ｎｉ３０
〜４９％，Ｃｒ１０〜１８％，Ａｌ１．６〜３．０％を
含み、ＩＶａ族とＶａ族から選ばれる１種または２種以
上の元素を合計で１．５〜８．０％含有し、残部は不純
物を除き本質的にＦｅからなるＦｅ−Ｎｉ−Ｃｒ基超耐
熱合金を基本組成とし、必要に応じてＭｏ３％以下とＷ
３％以下の１種または２種を含有できる。That is, in the present invention, C 0.15% by weight is used.
Below, Si 1.0% or less, Mn 3.0% or less, Ni30
.About.49%, Cr 10 to 18%, Al 1.6 to 3.0%, and one or more elements selected from the IVa group and the Va group in a total amount of 1.5 to 8.0%, The balance is a Fe-Ni-Cr-based superheat-resistant alloy consisting essentially of Fe, except for impurities, with a basic composition, and if necessary, Mo 3% or less and W.
One or two of 3% or less can be contained.

【００１２】より好適な範囲は、Ｃ０．０８％以下，Ｓ
ｉ０．５％以下，Ｍｎ１．０％以下，Ｎｉ３０〜４９
％，Ｃｒ１３〜１８％，Ａｌ１．６〜３．０％，Ｔｉ
１．５〜３．０％，Ｎｂ０．３〜２．５％を含み、残部
は不純物を除き本質的にＦｅからなるＦｅ−Ｎｉ−Ｃｒ
基超耐熱合金であり。これも必要に応じてＭｏ３％以下
とＷ３％以下の１種または２種を含有できるが、Ｍｏを
単独で３％以下含有させるのがより好ましい。さらに望
ましい範囲は、重量％でＣ０．０８％以下，Ｓｉ０．２
％以下，Ｍｎ０．５％以下，Ｎｉ３０〜４５％，Ｃｒ１
３．５〜１６％，Ｍｏ０．１〜１．０％，Ａｌ１．８〜
２．４％，Ｔｉ２．０〜３．０％，Ｎｂ０．５〜１．５
％である。これらの合金は、必要に応じて重量％で５％
以下のＣｏを、Ｎｉ＋Ｃｏ≦４９の範囲で含むことがで
きる。A more preferable range is C0.08% or less, S
i 0.5% or less, Mn 1.0% or less, Ni 30 to 49
%, Cr 13-18%, Al 1.6-3.0%, Ti
Fe-Ni-Cr containing 1.5 to 3.0%, Nb 0.3 to 2.5%, and the balance being essentially Fe except for impurities.
It is a base super heat resistant alloy. This may also contain one or two kinds of Mo 3% or less and W 3% or less, if necessary, but it is more preferable to contain Mo alone by 3% or less. A more desirable range is C0.08% or less by weight% and Si0.2.
% Or less, Mn 0.5% or less, Ni 30 to 45%, Cr1
3.5-16%, Mo 0.1-1.0%, Al 1.8-
2.4%, Ti 2.0 to 3.0%, Nb 0.5 to 1.5
%. These alloys, if required, may be 5% by weight.
The following Co can be contained in the range of Ni + Co ≦ 49.

【００１３】また上記の合金は、原子％で、Ａｌを必須
添加とし、ＩＶａ族およびＶａ族から選ばれる１種また
は２種以上の元素が，以下の関係式を満たす範囲で添加
するのがよい。 6.5≦[Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta]≦10.0 0.45≦[Al]/([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])≦0.
75 より好適な関係式を満たす範囲は、 6.5≦[Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta]≦8.5 0.50≦[Al]/([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])≦0.
60 である。In addition, Al is an essential addition to the above alloy, and it is preferable that one or more elements selected from the IVa group and the Va group are added within a range satisfying the following relational expression. . 6.5 ≦ [Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta] ≦ 10.0 0.45 ≦ [Al] / ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta]) ≦ 0.
75 The range satisfying the more preferable relational expression is 6.5 ≦ [Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta] ≦ 8.5 0.50 ≦ [Al] / ([ Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta]) ≦ 0.
60.

【００１４】また、上述の合金は、原子％でＣｒを必須
添加とし，さらにＭｏおよびＷの１種または２種が、１
３≦［Ｃｒ］＋［Ｍｏ］＋［Ｗ］≦１８の範囲で含むこ
とが望ましい。これらの合金は、必要に応じて０．０１
５％以下のＢ、０．０２％以下のＭｇと０．０２％以下
のＣａの１種または２種、さらに、０．１％以下のＹと
０．１％以下の希土類元素（以下ＲＥＭという）の１種
または２種を適宜含むことができる。これらの組成を有
する合金の一部は、８００℃にて４００時間加熱後のＵ
ノッチシャルピー衝撃値が０．５MJ/m²以上であること
を特徴とする。さらに，８００℃にて４００時間加熱後
の８００℃−２９４ＭＰａにおける回転曲げ疲労試験の
破断回数が０．５×１０⁶回以上であることを特徴とす
る。また、これらのＦｅ−Ｎｉ−Ｃｒ基超耐熱合金を用
いて製造される自動車用エンジンバルブと自動車用排ガ
ス触媒用ニットメッシュは、従来にない優れた特性を有
する。In the above alloy, Cr is essential added in atomic%, and 1 or 2 kinds of Mo and W are 1
It is desirable to include in the range of 3 ≦ [Cr] + [Mo] + [W] ≦ 18. These alloys can be added to 0.01
5% or less of B, one or two kinds of 0.02% or less of Mg and 0.02% or less of Ca, further 0.1% or less of Y and 0.1% or less of a rare earth element (hereinafter referred to as REM). 1) or 2) can be appropriately contained. Some of the alloys having these compositions have U after heating at 800 ° C. for 400 hours.
The notch Charpy impact value is 0.5 MJ / m ² or more. Further, the number of ruptures in the rotary bending fatigue test at 800 ° C.-294 MPa after heating at 800 ° C. for 400 hours is 0.5 × 10 ⁶ or more. Moreover, the engine valve for automobiles and the knit mesh for exhaust gas catalysts for automobiles, which are produced by using these Fe-Ni-Cr-based superheat-resistant alloys, have excellent properties that have never been obtained.

【００１５】[0015]

【作用】本発明において、ＣはＴｉやＮｂと結びついて
ＭＣ炭化物を形成し、結晶粒の粗大化防止やクリープ破
断延性の改善に役立つため、少量添加する必要がある。
しかし、０．１５％を超える過度の添加は、長時間加熱
時にＭＣ炭化物からＭ₂₃Ｃ₆炭化物への分解反応が多量
に生じて、常温における粒界の延性を低下させる。よっ
て、Ｃは０．１５％以下の添加とする。好適なＣの範囲
は、０．０８％以下である。In the present invention, C combines with Ti and Nb to form MC carbides, which helps prevent coarsening of crystal grains and improves creep rupture ductility, so it must be added in a small amount.
However, excessive addition exceeding 0.15%, the decomposition reaction of a long time during heating from MC carbides into M ₂₃ C ₆ carbides are large amount occurs, reduce the grain boundary ductility at room temperature. Therefore, C is added at 0.15% or less. The preferred range of C is 0.08% or less.

【００１６】ＳｉとＭｎは本発明合金において脱酸元素
として添加されるが、いずれも過度の添加は高温強度の
低下を招くため、Ｓｉは１．０％以下，Ｍｎは３．０％
以下にそれぞれ限定する。好適には、Ｓｉは０．５％以
下，Ｍｎは１．０％以下である。さらに望ましくは、Ｓ
ｉは０．２％以下、Ｍｎは０．５％以下である。Si and Mn are added as deoxidizing elements in the alloy of the present invention, but excessive addition of both causes reduction in high temperature strength, so Si is 1.0% or less and Mn is 3.0%.
Each is limited to the following. Preferably, Si is 0.5% or less and Mn is 1.0% or less. More preferably, S
i is 0.2% or less and Mn is 0.5% or less.

【００１７】Ｎｉは、基地のオーステナイト相を安定化
するとともに高温強度も高める。さらに、γ’相の構成
元素として、必須の添加元素である。Ｎｉが３０％を下
回るとγ’相の析出が不十分となり、高温強度が低下す
る。一方、Ｎｉ量が４９％を超えるとＮＣＦ７５１の省
資源材として価格上のメリットがなくなるため、Ｎｉ量
は３０〜４９％の範囲に限定する。より望ましいＮｉの
範囲は、３０〜４５％である。Ni stabilizes the austenite phase of the matrix and also enhances the high temperature strength. Further, it is an essential additional element as a constituent element of the γ'phase. If the Ni content is less than 30%, the precipitation of the γ'phase will be insufficient and the high temperature strength will be reduced. On the other hand, if the Ni content exceeds 49%, the merit in terms of cost as a resource saving material for NCF751 is lost, so the Ni content is limited to the range of 30 to 49%. A more desirable range of Ni is 30 to 45%.

【００１８】Ｃｒは合金に耐酸化性を付与するのに不可
欠の元素であり、自動車用等の耐熱部品としての耐酸化
性を保証するために最低１０％は必要であるが、１８％
を超えると組織が不安定となり、Ｃｒに富んだα’相ま
たはσ相などの有害脆化相を生成し、クリープ破断強度
と常温延性の低下を招くので、Ｃｒは１０〜１８％とす
る。好適なＣｒ量は１３〜１８％で、より望ましいＣｒ
量は１３．５〜１６％である。Cr is an essential element for imparting oxidation resistance to the alloy, and at least 10% is necessary to guarantee oxidation resistance as a heat resistant component for automobiles, but 18%.
If it exceeds, the structure becomes unstable, and a harmful embrittlement phase such as a Cr-rich α ′ phase or a σ phase is generated, leading to a decrease in creep rupture strength and room temperature ductility, so Cr is set to 10 to 18%. The preferable Cr amount is 13 to 18%, and more desirable Cr
The amount is 13.5-16%.

【００１９】Ａｌは前述のごとく安定なガンマプライム
相を析出させて所望の高温強度を得るために本発明にお
いて不可欠な元素であり、最低１．６％を必要とする
が、３．０％を越えると熱間加工性が劣化するので、
１．６〜３．０％に限定する。また、この高いＡｌ量
は、高温加熱時にAl₂O₃の生成量を増し耐酸化性の向上
にも寄与する。より望ましいＡｌ量は１．８〜２．４％
である。５０％を下回るＮｉ量と２０％以下のＣｒ量を
含有するFe-Ni基超耐熱合金の範疇にあって、このよう
にＡｌの添加量の高い合金は、これまでまったく存在せ
ず、この点が本発明のもっとも特徴とするところの１つ
である。As mentioned above, Al is an essential element in the present invention for precipitating a stable gamma prime phase to obtain a desired high temperature strength, and at least 1.6% is required, but 3.0% is required. If it exceeds, hot workability will deteriorate, so
It is limited to 1.6 to 3.0%. In addition, this high Al amount also increases the amount of Al ₂ O ₃ produced during high temperature heating and contributes to the improvement of oxidation resistance. A more desirable amount of Al is 1.8 to 2.4%
Is. In the category of Fe-Ni-based superheat-resistant alloys containing less than 50% Ni and less than 20% Cr, alloys with such high Al additions have never existed before. Is one of the most characteristic features of the present invention.

【００２０】ＩＶａ族、Ｖａ族の元素は本発明合金にお
いて、ＡｌとともにＮｉと結びついてガンマプライム相
を析出させ高温強度を高める作用があり、１種または２
種以上を合計で１．５％以上添加する必要がある。しか
し、これらの元素が合計で８．０％を越えると高温長時
間加熱時にガンマプライム相が不安定となってη相やδ
相等のγ相と非整合の金属間加工物を生成しやすくな
り、また熱間加工性も害するようになる。よってＩＶａ
族、Ｖａ族の元素は、１種または２種以上を合計で１．
５〜８．０％の添加とする。より望ましい範囲は、３．
０〜５．０％である。In the alloy of the present invention, the elements of group IVa and group Va have a function of combining with Al and Ni and precipitating a gamma prime phase to enhance the high temperature strength.
It is necessary to add at least 1.5% of the seeds or more in total. However, if the total content of these elements exceeds 8.0%, the gamma prime phase becomes unstable during high temperature and long time heating, resulting in η phase and δ phase.
It becomes easy to form an intermetallic work product that is inconsistent with the γ phase such as a phase, and also the hot workability is impaired. Therefore IVa
Group 1 and group 2 Va elements include one kind or two or more kinds in total.
The addition is 5 to 8.0%. A more desirable range is 3.
It is 0 to 5.0%.

【００２１】なお、ＩＶａ族の元素においては、Ｔｉの
添加がもっとも好ましく、好適なＴｉの添加量は、１．
５〜３．０％の範囲である。より望ましいＴｉの範囲は
２．０〜３．０％である。また、ＺｒとＨｆは、γ相へ
の固溶度がＴｉよりも低く、Ｔｉほど多量に添加できな
い。反面、一部が結晶粒界に偏析して、高温域での粒界
強度を高める作用ももつ。また、Ｖａ族の元素において
は、Ｎｂの添加がもっとも好ましく、好適なＮｂの添加
量は、０．３〜２．５％の範囲である。より望ましいＮ
ｂの範囲は、０．５〜１．５％である。一方、Ｖの場合
は、Ｎｂよりも固溶強化作用が弱く、また、耐酸化性も
低下させるので、過度の添加は好ましくない。また、Ｔ
ａの場合は、Ｎｂ以上にγ’相を固溶強化するが、希少
資源で価格が大幅に上昇することもあり、多量に添加す
るには至らない。It is most preferable to add Ti to the group IVa element, and the preferable addition amount of Ti is 1.
It is in the range of 5 to 3.0%. A more desirable Ti range is 2.0 to 3.0%. Further, Zr and Hf have a lower solid solubility in the γ phase than Ti and cannot be added in a large amount as much as Ti. On the other hand, a part of it is segregated at the crystal grain boundaries, and also has the effect of increasing the grain boundary strength in the high temperature region. Further, in the Va group element, the addition of Nb is most preferable, and the preferable addition amount of Nb is in the range of 0.3 to 2.5%. More desirable N
The range of b is 0.5 to 1.5%. On the other hand, in the case of V, the solid solution strengthening action is weaker than that of Nb, and the oxidation resistance is also lowered, so excessive addition is not preferable. Also, T
In the case of a, the γ'phase is solid-solution strengthened above Nb, but the price may increase significantly due to scarce resources, so it cannot be added in a large amount.

【００２２】ＭｏとＷはＣｒと同じＶＩａ族の元素で、
ともにオーステナイト基地を固溶強化し、高温疲労強度
と高温クリープ破断強度を高める効果をもつ。そのため
に必要に応じてＭｏとＷの１種または２種をそれぞれ３
％以下の範囲で添加できる。しかし、合金価格と比重の
点ではＭｏの方が望ましく、その場合のより望ましいＭ
ｏ量は０．１〜１．０％である。また、α’相やσ相の
析出にはＣｒ量とあわせこれら３元素の原子％における
総和が効いてくるため、Ｃｒと同族の元素であるＭｏと
Ｗの添加量についても必要に応じて、重量％を原子％に
換算した場合の総和を一定値に保つことが望ましい。よ
って原子％で表される［Ｃｒ］＋［Ｍｏ］＋［Ｗ］量
は，１３〜１８とすることが望ましい。さらに望ましい
範囲は、１５．０〜１７．５の範囲である。Ｃｏはオー
ステナイト基地に固溶して、熱間加工域では、γ’相の
固溶を促進させ加工性を改善する一方、実用温度域で
は、γ’相の析出量を増加させ、高温強度を高める。そ
のために、Ｃｏは必要に応じて、Ｎｉ量と置換する形
で、Ｎｉ＋Ｃｏ≦４９の範囲で添加することができる
が、ＣｏはＮｉに比べて高価な元素であるため、上限は
５．０％とするのが良い。Mo and W are the same VIa group elements as Cr,
Both have the effect of solid-solution strengthening the austenite matrix and increasing high temperature fatigue strength and high temperature creep rupture strength. For that purpose, one or two kinds of Mo and W may be added to each 3
It can be added in the range of not more than%. However, Mo is preferable in terms of alloy price and specific gravity, and M in that case is more preferable.
The amount of o is 0.1 to 1.0%. In addition, since the sum of these three elements in atomic% together with the Cr content is effective for the precipitation of the α ′ phase and the σ phase, the addition amounts of Mo and W, which are elements in the same family as Cr, may be adjusted as necessary. It is desirable to maintain a constant total value when weight% is converted to atomic%. Therefore, it is desirable that the amount of [Cr] + [Mo] + [W] expressed in atomic% be 13-18. A more desirable range is 15.0 to 17.5. Co forms a solid solution in the austenite matrix and promotes the solid solution of the γ'phase in the hot working region to improve the workability, while increasing the precipitation amount of the γ'phase and increasing the high temperature strength in the practical temperature range. Increase. Therefore, Co can be added in the range of Ni + Co ≦ 49 in a form of substituting with the amount of Ni, if necessary, but since Co is an expensive element compared to Ni, the upper limit is 5.0%. It is good to

【００２３】本発明の目的の達成のためにはＡｌとＩＶ
ａ族元素およびＶａ族元素はそれぞれ単独に上述の成分
範囲を満足する必要があるだけでなく、ガンマプライム
構成元素として、それぞれの元素の総和ならびにＡｌの
比率を適正範囲とすることも重要である。前述のとお
り、Ni₃(Al,IVa,Va)からなるγ’相において、原子％で
表される[Al]/([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])の
量を高めることで、γ’相を安定化することができる。
この[Al]/([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])比が
０．４５に満たないと、長時間加熱時にγ’相からη相
やδ相への変態による高温強度の低下が生じやすくな
る。一方、この量比が０．７５を超えるとγ’相が十分
に固溶強化されず、常温強度が低下する。よって、[Al]
/([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])比は０．４５〜
０．７５の範囲が望ましい。より望ましくは０．５０〜
０．６０の範囲である。To achieve the object of the present invention, Al and IV
Not only is it necessary for each of the a-group element and the Va-group element to independently satisfy the above-mentioned range of components, it is also important to make the sum of the respective elements and the ratio of Al within the proper ranges as gamma prime constituent elements. . As mentioned above, in the γ'phase composed of Ni ₃ (Al, IVa, Va), [Al] / ([Al] + [Ti] + [Zr] + [Hf] + [V] expressed in atomic% By increasing the amount of + [Nb] + [Ta]), the γ'phase can be stabilized.
If this [Al] / ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta]) ratio is less than 0.45, γ ' The high temperature strength tends to decrease due to the transformation from the phase to the η phase or the δ phase. On the other hand, if this amount ratio exceeds 0.75, the γ'phase is not sufficiently solid-solution strengthened, and the room temperature strength decreases. Therefore, [Al]
/ ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta]) ratio is 0.45
The range of 0.75 is desirable. More preferably 0.50
The range is 0.60.

【００２４】さらに、マトリックスのＮｉ量低下による
高温強度の低下をγ’相の増量で補うために、原子％で
表される([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])量につ
いても適性範囲に制御するのが良い。この値が、６．５
を下回ると、Ｎｉ量が５０％を越える従来のFe-Ni-Cr基
超耐熱合金の強度に及ばないようになり、逆に１０を超
えるとエンジンバルブ用等の熱間加工が困難となる。よ
って、原子％で表される([Al]+[Ti]+[Zr]+[Hf]+[V]+[N
b]+[Ta])量は、従来の鍛造合金よりも高い６．５〜１
０．０の範囲に管理することで、短時間高温強度の向上
が可能となる。より好適な範囲は、７．０〜８．５であ
る。このように高い計算γ’量がエンジンバルブ用など
の鍛造合金で、実用化されたことはなく、この点も全く
新規の発明である。Ｎｉ量が５０％以上のＮｉ基超耐熱
合金の場合、γ’相が高温まで安定となりこのレベルの
γ’量ではエンジンバルブ等の強度の熱間加工が困難と
なる。Further, in order to compensate the decrease in high temperature strength due to the decrease in the Ni content of the matrix by the increase in the γ'phase, it is expressed in atomic% ([Al] + [Ti] + [Zr] + [Hf] + [ The amount of V] + [Nb] + [Ta]) should also be controlled within an appropriate range. This value is 6.5
If it is less than 10, the strength of the conventional Fe-Ni-Cr-based superheat-resistant alloy in which the amount of Ni exceeds 50% is not reached, and conversely, if it exceeds 10, hot working for engine valves and the like becomes difficult. Therefore, it is represented by atomic% ([Al] + [Ti] + [Zr] + [Hf] + [V] + [N
b] + [Ta]) amount is higher than that of conventional forged alloys 6.5-1
By controlling the range to 0.0, it becomes possible to improve the high temperature strength for a short time. A more preferable range is 7.0 to 8.5. Such a high calculated γ ′ amount has never been put to practical use in a forged alloy for engine valves or the like, and this is also a completely new invention. In the case of a Ni-base superheat-resistant alloy having a Ni content of 50% or more, the γ'phase is stable up to high temperatures, and with this level of γ'amount, it becomes difficult to perform hot working with high strength for engine valves and the like.

【００２５】また、原子％で表される上述した[Al]/([A
l]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])量が低い合金の場合
も,Ti,Nb,Ta等の元素の固溶強化とγ’相の格子ひずみ
量の増加によって、熱間加工が困難となる。よって、こ
のような高い計算γ’量はＮｉ量が５０％を超えず、か
つ[Al]/([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])量比が高
い場合のみ熱間加工が可能となる。上述の関係式で表さ
れる原子％のうち、無添加の元素については、ゼロとし
て計算する。Further, the above-mentioned [Al] / ([A
[l] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta]) Even in the case of alloys with low amount, solid solution strengthening of elements such as Ti, Nb, Ta and γ ' Due to the increase in the amount of lattice strain of the phase, hot working becomes difficult. Therefore, in such a high calculated γ ′ amount, the Ni amount does not exceed 50%, and [Al] / ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + Hot working is possible only when the [Ta]) amount ratio is high. Of the atomic% represented by the above relational expression, the element without addition is calculated as zero.

【００２６】Ｂは、本発明において粒界強化作用により
高温の強度と延性を高めるのに有効であり、本発明合金
に適量添加できる。その効果は少量の添加量から始まる
が、０．０１５％を超えると加熱時の初期溶融温度が低
下して熱間加工性が劣化するので、Ｂの上限は、０．０
１５％とするのが良い。ＭｇとＣａは、強力な脱酸・脱
硫元素として合金の清浄度を高めるとともに、高温引張
やクリープ変形時さらに熱間加工時の延性改善に役立つ
ため、１種または２種を適量添加できる。その効果は少
量の添加量から始まるが、Ｍｇ，Ｃａがそれぞれ、０．
０２％を超えると加熱時の初期溶融温度が低下して熱間
加工性が劣化するので、ＭｇおよびＣａの上限は、それ
ぞれ０．０２％とするのが良い。In the present invention, B is effective in increasing the strength and ductility at high temperature due to the grain boundary strengthening action, and can be added in an appropriate amount to the alloy of the present invention. The effect starts from a small amount of addition, but if it exceeds 0.015%, the initial melting temperature during heating is lowered and the hot workability is deteriorated, so the upper limit of B is 0.0
15% is good. Since Mg and Ca serve as strong deoxidizing / desulfurizing elements to improve the cleanliness of the alloy and to help improve ductility during high temperature tension and creep deformation and during hot working, one or two kinds can be added in appropriate amounts. The effect starts from a small amount of addition, but Mg and Ca each have an amount of 0.
If it exceeds 02%, the initial melting temperature at the time of heating decreases and the hot workability deteriorates. Therefore, the upper limits of Mg and Ca are preferably 0.02%.

【００２７】ＹおよびＲＥＭは、本発明において高温の
耐酸化性を高めるのに有効であり、本発明合金に１種ま
たは２種を適量添加できる。その効果は少量の添加量か
ら始まるが、ＹおよびＲＥＭがそれぞれ、０．１％を超
えると加熱時の初期溶融温度が低下して熱間加工性が劣
化するので、ＹおよびＲＥＭの上限は、それぞれ０．１
％とするのが良い。なお、本発明合金をベースに、耐酸
化性を限界まで高めるために、ランタノイドの元素群の
中から最適な添加割合を求めることは容易であり、この
ような操作は、本発明の範囲を越えるものではない。Y and REM are effective in increasing the oxidation resistance at high temperature in the present invention, and one or two kinds can be added in appropriate amounts to the alloy of the present invention. The effect starts from a small amount of addition, but if Y and REM exceed 0.1%, the initial melting temperature at the time of heating decreases and the hot workability deteriorates, so the upper limits of Y and REM are: 0.1 each
It is good to set it as%. In addition, it is easy to obtain the optimum addition ratio from the lanthanoid element group in order to increase the oxidation resistance to the limit based on the alloy of the present invention, and such an operation is beyond the scope of the present invention. Not a thing.

【００２８】また、請求項には挙げていないが、Ｒｅ
は、オーステナイト基地を固溶強化し、同時にγ’相の
析出も促進し、高温耐食性にも有効に働くため、本発明
合金に２．０％以下の範囲で添加してもよい。ただし、
希少資源で合金価格が大幅に高くなるので、過度に添加
する必要はない。Ｆｅは、省資源合金として安価なオー
ステナイト基地を形成するのに有効な元素である。ま
た、Ｎｉよりも高温域で基地を軟化させるので、上述の
強化合金元素量を含んでも熱間加工が可能となる。以上
の理由によりＦｅは不可避の不純物を除き残部とする。
また、不純物のうち、下記の元素については、以下に示
す範囲であれば本発明合金に含まれてもよい。 Ｐ≦０．０４％， Ｓ≦０．０２％， Ｏ≦０．０２
％， Ｎ≦０．０５％ より望ましくは、以下の範囲である。 Ｐ≦０．０２％， Ｓ≦０．００５％， Ｏ≦０．０１
％， Ｎ≦０．０１％ 以上述べたFe-Ni-Cr基超耐熱合金は、単一の真空溶解、
または真空溶解後のエレクトロスラグ再溶解や真空アー
ク再溶解等の精練工程を経て得られたインゴットを熱間
鍛造や熱間圧延等の加工工程を通して１次製品に仕上げ
られる。Although not mentioned in the claims, Re
May strengthen the austenite matrix in a solid solution, promote the precipitation of the γ'phase at the same time, and effectively act on the high temperature corrosion resistance. Therefore, it may be added to the alloy of the present invention in the range of 2.0% or less. However,
It is not necessary to add it excessively because the alloy price will rise significantly due to scarce resources. Fe is an element effective as a resource-saving alloy for forming an inexpensive austenite base. Further, since the matrix is softened in a temperature range higher than that of Ni, hot working is possible even when the above-mentioned amount of the strengthening alloying element is included. For the above reasons, Fe is the balance except for the inevitable impurities.
Further, among the impurities, the following elements may be included in the alloy of the present invention within the ranges shown below. P ≦ 0.04%, S ≦ 0.02%, O ≦ 0.02
%, N ≦ 0.05% More preferably, the range is as follows. P ≦ 0.02%, S ≦ 0.005%, O ≦ 0.01
%, N ≦ 0.01% The above-mentioned Fe-Ni-Cr based super heat resistant alloy is a single vacuum melting,
Alternatively, an ingot obtained through a refining process such as electroslag remelting after vacuum melting or vacuum arc remelting is finished into a primary product through a working process such as hot forging and hot rolling.

【００２９】これらの素材はγ’析出強化型超耐熱合金
に一般的に用いられる９００〜１１００℃の固溶化処理
と６００〜８００℃の時効処理を実施したのち実用に供
される。熱間加工が固溶化処理を兼ねる場合は、熱間加
工後、直接時効処理を実施してもよい。本合金はさらに
実用を模擬した長時間加熱処理、例えば、８００℃にて
４００時間程度の長時間加熱を実施したのちの状態でも
十分な常温の靭性・延性が得られる。これは従来の高Ｃ
ｒのＦｅ−Ｎｉ−Ｃｒ基超耐熱合金では、得られなかっ
た特性で、具体的な数値としてはシャルピー衝撃値で
０．５MJ/m²以上の値が得られる。These materials are put to practical use after being subjected to a solution treatment at 900 to 1100 ° C. and an aging treatment at 600 to 800 ° C. which are generally used for γ'precipitation strengthened super heat resistant alloys. When the hot working also serves as a solution treatment, the aging treatment may be directly performed after the hot working. The present alloy can obtain sufficient toughness and ductility at room temperature even after being subjected to a long-term heat treatment simulating practical use, for example, a long-term heating at 800 ° C. for about 400 hours. This is the conventional high C
With the r-Fe-Ni-Cr-based superheat-resistant alloy, a characteristic that could not be obtained, and as a concrete numerical value, a Charpy impact value of 0.5 MJ / m ² or more was obtained.

【００３０】これらは自動車の保証期間増加に伴い、従
来よりも各部品材の耐久性を改善する必要性が出てきた
ために、あらたに着目した特性である。自動車エンジン
用バルブ材として８００℃で４００時間加熱後の衝撃値
が０．５MJ/m²に満たないと長期使用後のエンジンを寒
冷地で急速に高温まで回転させた場合等に、靭性が不十
分なためにバルブの折損につながる可能性がある。した
がって、必要に応じ、本発明合金の８００℃で４００時
間加熱後の衝撃値は０．５MJ/m²以上に規定するのが良
い。また、本合金は同じく８００℃にて４００時間加熱
したのちの状態でも十分な疲労強度が得られる。エンジ
ンバルブのように高温で繰り返し応力が働く部材におい
て、寿命を律速する最大の因子は疲労であり、自動車の
保証期間の延長に伴い、バルブの性能を保証するために
は、８００℃にて４００時間加熱後の８００℃−２９４
ＭＰａの試験条件下での回転曲げ疲労破断回数が０．５
×１０⁶回以上に規定するのが良い。より望ましい破断
回数は２．５×１０⁶回以上である。本発明合金は、最
適な熱処理条件下においてこれらの疲労強度を満足する
ことができる。These characteristics are the characteristics that pay attention to the new characteristics because it is necessary to improve the durability of each component material as compared with the conventional one as the warranty period of the automobile increases. If the impact value after heating at 800 ° C for 400 hours as a valve material for automobile engine is less than 0.5MJ / m ² , the toughness is unsatisfactory when the engine is used for a long time and rapidly rotated to a high temperature in cold regions. Sufficient may lead to valve breakage. Therefore, if necessary, the impact value after heating the alloy of the present invention at 800 ° C. for 400 hours is preferably specified to be 0.5 MJ / m ² or more. Further, the present alloy also has sufficient fatigue strength even after being heated at 800 ° C. for 400 hours. In a member such as an engine valve, which is subjected to repeated stress at high temperature, fatigue is the greatest factor that determines the life. With the extension of the warranty period of automobiles, in order to guarantee the performance of the valve, 400 ° C. at 800 ° C. After heating for 800 hours-294
The number of rotational bending fatigue ruptures under the MPa test condition is 0.5
It is preferable to specify x10 ⁶ times or more. The more desirable number of breaks is 2.5 × 10 ⁶ or more. The alloy of the present invention can satisfy these fatigue strengths under optimum heat treatment conditions.

【００３１】本発明合金は、これら高温長時間加熱後の
優れた常温靭性と高い高温疲労強度を両立することがで
きる。これは、従来のＦｅ−Ｎｉ−Ｃｒ基超耐熱合金で
は為し得なかった性能であり、本発明合金がもつ優れた
性質を具体的に表す数値である。さらに本合金製の熱間
圧延棒材を必要寸法に切断後、熱間据え込み鍛造や熱間
押し出しによって成型された自動車用エンジンバルブ
は、高温疲労強度、高温硬度、組織安定性、耐酸化性お
よび長時間加熱後の常・高温強度に優れたバルブフェー
ス部の肉盛り不要の安価な省資源バルブであり、自動車
の経済性に大きく寄与することができる。なお、このエ
ンジンバルブは、種々のプロセスによる表面窒化や各種
硬質めっきを施して使用することもできる。さらに軸部
側に各種耐熱鋼や高硬度の合金工具鋼を溶接した接合バ
ルブとしても使用できる。また、種々の加工方法によ
り、中空エンジンバルブとして使用するとさらに耐久性
が向上する。The alloy of the present invention can achieve both excellent room temperature toughness after high temperature and long time heating and high high temperature fatigue strength. This is a performance that could not be achieved with the conventional Fe-Ni-Cr-based superheat-resistant alloy, and is a numerical value that specifically represents the excellent properties of the alloy of the present invention. Furthermore, automotive engine valves molded by hot upsetting and hot extrusion after cutting the hot rolled bar made of this alloy to the required size have high temperature fatigue strength, high temperature hardness, microstructure stability and oxidation resistance. Also, it is an inexpensive resource-saving valve that does not require padding of the valve face portion that is excellent in normal / high temperature strength after being heated for a long time, and can greatly contribute to the economical efficiency of automobiles. The engine valve can also be used after being subjected to surface nitriding by various processes or various hard plating. It can also be used as a joint valve by welding various heat resistant steels and high hardness alloy tool steels to the shaft side. Further, the durability is further improved by using it as a hollow engine valve by various processing methods.

【００３２】また、本合金製の熱間圧延棒材を固溶化処
理した状態から冷間あるいは温間加工と焼鈍の繰り返し
により、最小直径0.2mm程度のワイヤーに加工し、排ガ
ス触媒のセラミック担体を支えるニットメッシュに成形
すると、従来のニットメッシュ材であるSUS310S等のス
テンレス鋼に比べてより優れた耐酸化性と高温強度を有
するため、高い信頼性と耐久性に優れたニットメッシュ
が得られる。Further, the hot-rolled bar made of the present alloy is processed into a wire having a minimum diameter of about 0.2 mm by repeating cold or warm working and annealing from the solution-treated state, and a ceramic carrier for an exhaust gas catalyst is obtained. When formed into a supporting knit mesh, it has superior oxidation resistance and high-temperature strength compared to conventional knit mesh materials such as SUS310S and other stainless steels, so that a knit mesh with high reliability and durability can be obtained.

【００３３】[0033]

【実施例】【Example】

（実施例１）表１に示す組成の合金を真空誘導溶解によ
って１０kgのインゴットにした後、熱間加工によって３
０mm角の棒材を作成した（ＲＥＭはミッシュメタルとし
て添加）。これに１０５０℃×３０分保持後水冷の固溶
化処理と７５０℃×４時間保持後空冷の時効処理を行な
い、この標準熱処理ままおよびさらにこの状態から８０
０℃×４００時間保持した後の常温硬さ、常温シャルピ
ー衝撃試験、常温および８００℃の引張試験、８００℃
−２９４ＭＰａの条件下での回転曲げ疲労試験を実施し
た。さらに８５０℃×４００ｈ加熱時の耐酸化性につい
ても調査した。常温硬度は、ロックウェル硬度計により
測定した。シャルピー衝撃試験は試験温度２０℃で、Ｊ
ＩＳ法により、２Ｕノッチ３号試験片を用いて測定し
た。また、引張試験はＡＳＴＭ法により、平行部直径6.
35mm、伸び４Ｄにて測定した。回転曲げ疲労試験は、Ｊ
ＩＳ Ｚ２２７４号に従い、平行部直径8mmの試験片を
用いて、回転数３６００回転で、試験片が破断するまで
の回数を求めた。さらに耐酸化試験は直径10mm、長さ20
mmの丸棒試験片を用いて８５０℃×４００時間加熱前後
の重量測定による酸化重量変化を評価した。各種試験結
果を表２に示す。(Example 1) After alloys having the compositions shown in Table 1 were made into 10 kg ingots by vacuum induction melting, they were hot-worked to 3
A 0 mm square rod was created (REM was added as misch metal). This was subjected to a solution treatment of water cooling after holding at 1050 ° C. for 30 minutes and an aging treatment of holding at 750 ° C. for 4 hours and then air cooling.
Room temperature hardness after holding at 0 ℃ x 400 hours, normal temperature Charpy impact test, normal temperature and 800 ℃ tensile test, 800 ℃
A rotary bending fatigue test was carried out under the condition of -294 MPa. Further, the oxidation resistance when heated at 850 ° C. for 400 hours was also investigated. The room temperature hardness was measured with a Rockwell hardness meter. Charpy impact test at a test temperature of 20 ℃, J
It was measured by the IS method using a 2U notch No. 3 test piece. The tensile test is based on the ASTM method.
It was measured at 35 mm and elongation of 4D. The rotary bending fatigue test is J
According to IS Z2274, a test piece having a parallel part diameter of 8 mm was used, and the number of times until the test piece broke at 3600 rotations was determined. Furthermore, the oxidation resistance test is 10 mm in diameter and 20 in length.
The change in oxidative weight by weight measurement before and after heating at 850 ° C. for 400 hours was evaluated using a mm round bar test piece. The results of various tests are shown in Table 2.

【００３４】[0034]

【表１】 [Table 1]

【００３５】[0035]

【表２】 [Table 2]

【００３６】表１のＮｏ．１〜２１は本発明合金、Ｎ
ｏ．３１〜３３は比較合金、Ｎｏ．４１は特公平４−１
１６１３号に開示される従来合金である。表１の各種化
学組成に併記したＡ値、Ｂ値、およびＣ値は、それぞれ
原子％で表される[Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta]
量、[Al]/([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])量、お
よび[Cr]+[Mo]+[W]量である。なお、これらの計算にあ
たって、ＲＥＭの添加量はＬａの原子量を代表値として
用いた。また、Ａ値とＢ値の関係を図１に示す。本発明
合金の各種機械的性質および耐酸化性は、６０％のＮｉ
を含む従来合金Ｎｏ．４１と同等以上の優れた特性が得
られており、いかに本発明合金が省資源の優れた耐熱合
金であるかがわかる。No. 1 in Table 1 1 to 21 are alloys of the present invention, N
o. 31-33 are comparative alloys, No. 41 is 4-1
It is a conventional alloy disclosed in No. 1613. The A value, B value, and C value shown together with the various chemical compositions in Table 1 are each expressed in atomic% [Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb]. + [Ta]
Amount, [Al] / ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta]) amount, and [Cr] + [Mo] + [W] amount Is. In addition, in these calculations, the atomic amount of La was used as a representative value for the amount of REM added. The relationship between the A value and the B value is shown in FIG. The various mechanical properties and oxidation resistance of the alloy of the present invention are 60% Ni.
Conventional alloy No. including Excellent properties equal to or higher than those of No. 41 were obtained, and it can be seen how the alloy of the present invention is a heat-resistant alloy excellent in resource saving.

【００３７】一方、比較合金のうちＮｏ．３１は熱間鍛
造時に割れが発生し評価試験を実施しなかった。これは
表１のＩＶａ族とＶａ族の和が８．２％と高く、併せて
Ａ値が高すぎたことによるものである。また、Ｎｏ．３
２は図１に示すように、Ａ値およびＢ値は本発明合金と
同じレベルにあり、標準熱処理後の機械的性質は優れて
いるが、長時間加熱後の常温の引張絞り、およびシャル
ピー衝撃値が大きく低下している。これは、Ｃｒ量およ
びＣ値が高すぎるために結晶粒界にσ相が析出したため
である。また、Ｎｏ．３３は標準熱処理後の機械的性質
は優れているが、長時間加熱後の高温引張強度と回転曲
げ疲労破断回数が本発明合金に比べて低く、また常温の
引張絞りやシャルピー衝撃値の低下量が大きい。これら
はＡｌ量と図１に示すようにＢ値が低いために長時間加
熱中にγ’相の粗大化とγ’相からη相への変態が生じ
たためである。On the other hand, of the comparative alloys, No. No. 31 did not undergo an evaluation test because cracking occurred during hot forging. This is because the sum of IVa group and Va group in Table 1 was as high as 8.2%, and in addition, the A value was too high. In addition, No. Three
As shown in FIG. 1, No. 2 has the A value and the B value at the same level as the alloy of the present invention, and the mechanical properties after the standard heat treatment are excellent, but the tensile drawing at room temperature after a long time heating and the Charpy impact The value is greatly reduced. This is because the amount of Cr and the C value were too high and the σ phase was precipitated at the crystal grain boundaries. In addition, No. No. 33 has excellent mechanical properties after the standard heat treatment, but the high temperature tensile strength and the number of rotational bending fatigue ruptures after long-time heating are lower than those of the alloys of the present invention, and the reduction in tensile drawing and Charpy impact value at room temperature. Is big. These are because the amount of Al and the B value as shown in FIG. 1 are low, so that the γ ′ phase is coarsened and the γ ′ phase is transformed to the η phase during long-time heating.

【００３８】（実施例２）表１の本発明合金Ｎｏ．２を
さらに熱間鍛造と切削および研削加工により、直径６mm
の丸棒に仕上げた。さらにこの丸棒の１端を熱間据え込
みにより、エンジンバルブの形状に成形した。このエン
ジンバルブと特公平４−１１６１３号に開示される従来
合金製の量産エンジンバルブを実施例１に記載の標準熱
処理を実施した後、無鉛ガソリン仕様のエンジンテスタ
ーを用いてベンチテストを実施した。試験条件は高速高
温連続耐久試験として、バルブの最高温度が７８０〜８
３０℃となる条件を選び、４００時間の連続運転を行な
った。試験終了後、本発明合金と従来合金製のエンジン
バルブの形状変化および断面の腐食状況を確認したとこ
ろ、両者ともまったく実用に問題ないレベルの性状であ
ることが確認できた。(Example 2) Inventive alloy No. 1 in Table 1 2 is 6mm in diameter by hot forging, cutting and grinding.
Finished into a round bar. Further, one end of this round bar was hot upset to form an engine valve shape. This engine valve and a conventional alloy mass-produced engine valve disclosed in Japanese Examined Patent Publication No. 4-11613 were subjected to the standard heat treatment described in Example 1, and then a bench test was performed using an unleaded gasoline engine tester. The test conditions are high-speed high-temperature continuous durability test, and the maximum temperature of the valve is 780-8
A condition of 30 ° C. was selected, and continuous operation was performed for 400 hours. After the test was completed, the shape change and the cross-sectional corrosion state of the engine valve made of the alloy of the present invention and the conventional alloy were confirmed, and it was confirmed that both were in a level of no problem for practical use.

【００３９】（実施例３）実施例２の本発明合金Ｎｏ．
２製の６mmの丸棒を冷間引抜と焼鈍の繰り返しで、直径
0.25mmのワイヤーに加工したのち、排ガス触媒用セラミ
ック担体のニットメッシュに成形した。この触媒ユニッ
トを実施例２のベンチテスト時に同時に組み入れ、ニッ
トメッシュとしての性能を調査した。ニットメッシュの
温度はバルブの温度よりさらに高温であるが、試験終了
後、本発明合金製のニットメッシュはクリープ変形や異
常酸化を起こすことなく、排ガスニットメッシュとして
も優れた性能を有することがわかった。(Example 3) The alloy No. of the present invention of Example 2 was used.
The diameter of a 6 mm round rod made of 2 is repeatedly drawn by cold drawing and annealing.
After processing into a wire of 0.25 mm, it was formed into a knit mesh of a ceramic carrier for exhaust gas catalyst. This catalyst unit was simultaneously incorporated in the bench test of Example 2 to investigate the performance as a knit mesh. The temperature of the knit mesh is higher than the temperature of the valve, but after the test, the knit mesh made of the alloy of the present invention was found to have excellent performance as an exhaust gas knit mesh without causing creep deformation or abnormal oxidation. It was

【００４０】[0040]

【発明の効果】本発明によれば、エンジンバルブ等に使
用される５０％以上のＮｉを含むＮｉ基超耐熱合金と同
等以上の優れた組織安定性、長時間加熱後の優れた常温
・高温の引張性質、高温耐酸化性、優れた高温疲労特性
および耐食性を有する省資源かつ安価なＦｅ−Ｎｉ−Ｃ
ｒ基超耐熱合金が得られ、この合金を用いたエンジンバ
ルブや排ガス触媒用ニットメッシュを自動車エンジンに
使用すると経済性と耐久性にすぐれた信頼性の高いエン
ジンを製造することができる。EFFECTS OF THE INVENTION According to the present invention, excellent structural stability equal to or higher than that of Ni-base superalloys containing 50% or more of Ni used in engine valves and the like, and excellent room temperature and high temperature after long time heating. Resource-saving and inexpensive Fe-Ni-C having excellent tensile properties, high temperature oxidation resistance, excellent high temperature fatigue characteristics and corrosion resistance
An r-base super heat-resistant alloy is obtained, and when an engine valve or an exhaust gas catalyst knit mesh using this alloy is used in an automobile engine, a highly reliable engine excellent in economy and durability can be manufactured.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明合金、比較合金および従来合金の組成の
うち、[Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta]と、[Al]/
([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])の関係をプロッ
トした図である。1] Among the compositions of the present invention alloy, comparative alloy and conventional alloy, [Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta] and [Al] /
It is the figure which plotted the relationship of ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta]).

───────────────────────────────────────────────────── フロントページの続き (72)発明者 佐藤 克明 埼玉県和光市中央１丁目４番１号 株式会 社本田技術研究所内 (72)発明者 坂 勉 埼玉県和光市中央１丁目４番１号 株式会 社本田技術研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuaki Sato 1-4-1 Chuo, Wako-shi, Saitama Inside of Honda R & D Co., Ltd. (72) Inventor Tsutomu Saka 1-4-1 Chuo, Wako, Saitama Stock Company Honda Technical Research Institute

Claims (17)

【特許請求の範囲】[Claims] 【請求項１】 重量％でＣ０．１５％以下，Ｓｉ１．０
％以下，Ｍｎ３．０％以下，Ｎｉ３０〜４９％，Ｃｒ１
０〜１８％，Ａｌ１．６〜３．０％を含み、ＩＶａ族と
Ｖａ族から選ばれる１種または２種以上の元素を合計で
１．５〜８．０％含有し、残部は不純物を除き本質的に
Ｆｅからなることを特徴とするＦｅ−Ｎｉ−Ｃｒ基超耐
熱合金。1. C0.15% or less by weight%, Si1.0
% Or less, Mn 3.0% or less, Ni 30 to 49%, Cr1
0 to 18%, Al 1.6 to 3.0%, one or more elements selected from the IVa group and the Va group in a total amount of 1.5 to 8.0%, and the balance containing impurities. Fe-Ni-Cr based super heat resistant alloy characterized by being essentially composed of Fe. 【請求項２】 重量％でＣ０．１５％以下，Ｓｉ１．０
％以下，Ｍｎ３．０％以下，Ｎｉ３０〜４９％，Ｃｒ１
０〜１８％，Ｍｏ３％以下とＷ３％以下の１種または２
種，Ａｌ１．６〜３．０％を含み、ＩＶａ族とＶａ族か
ら選ばれる１種または２種以上の元素を合計で１．５〜
８．０％含有し、残部は不純物を除き本質的にＦｅから
なることを特徴とするＦｅ−Ｎｉ−Ｃｒ基超耐熱合金。2. C0.15% or less by weight%, Si1.0
% Or less, Mn 3.0% or less, Ni 30 to 49%, Cr1
0-18%, Mo 3% or less and W3% or less 1 type or 2
, Al 1.6 to 3.0%, and one or more elements selected from the IVa group and the Va group in total of 1.5 to
Fe-Ni-Cr based super heat resistant alloy containing 8.0% and the balance being essentially Fe except impurities. 【請求項３】 重量％でＣ０．０８％以下，Ｓｉ０．５
％以下，Ｍｎ１．０％以下，Ｎｉ３０〜４９％，Ｃｒ１
３〜１８％，Ａｌ１．６〜３．０％，Ｔｉ１．５〜３．
０％，Ｎｂ０．３〜２．５％を含み、残部は不純物を除
き本質的にＦｅからなることを特徴とするＦｅ−Ｎｉ−
Ｃｒ基超耐熱合金。3. C0.08% or less by weight%, Si0.5
% Or less, Mn 1.0% or less, Ni 30 to 49%, Cr1
3-18%, Al1.6-3.0%, Ti1.5-3.
Fe-Ni- characterized in that it contains 0% and 0.3-2.5% Nb, and the balance is essentially Fe except for impurities.
Cr-based super heat resistant alloy. 【請求項４】 重量％でＣ０．０８％以下，Ｓｉ０．５
％以下，Ｍｎ１．０％以下，Ｎｉ３０〜４９％，Ｃｒ１
３〜１８％，Ｍｏ３％以下とＷ３％以下の１種または２
種，Ａｌ１．６〜３．０％，Ｔｉ１．５〜３．０％，Ｎ
ｂ０．３〜２．５％を含み、残部は不純物を除き本質的
にＦｅからなることを特徴とするＦｅ−Ｎｉ−Ｃｒ基超
耐熱合金。4. C0.08% or less by weight%, Si0.5
% Or less, Mn 1.0% or less, Ni 30 to 49%, Cr1
3-18%, Mo 3% or less and W3% or less 1 type or 2
Seed, Al 1.6-3.0%, Ti 1.5-3.0%, N
b Fe 0.3-2.5%, and the balance is essentially Fe except for impurities, Fe-Ni-Cr base super heat resistant alloy characterized by the above-mentioned. 【請求項５】 重量％でＣ０．０８％以下，Ｓｉ０．５
％以下，Ｍｎ１．０％以下，Ｎｉ３０〜４９％，Ｃｒ１
３〜１８％，Ｍｏ３％以下，Ａｌ１．６〜３．０％，Ｔ
ｉ１．５〜３．０％，Ｎｂ０．３〜２．５％を含み、残
部は不純物を除き本質的にＦｅからなることを特徴とす
るＦｅ−Ｎｉ−Ｃｒ基超耐熱合金。5. C0.08% or less by weight%, Si0.5
% Or less, Mn 1.0% or less, Ni 30 to 49%, Cr1
3-18%, Mo 3% or less, Al 1.6-3.0%, T
A Fe-Ni-Cr based super heat-resistant alloy, characterized in that it contains i1.5 to 3.0% and Nb 0.3 to 2.5%, and the balance is essentially Fe except impurities. 【請求項６】 重量％でＣ０．０８％以下，Ｓｉ０．２
％以下，Ｍｎ０．５％以下，Ｎｉ３０〜４５％，Ｃｒ１
３．５〜１６％，Ｍｏ０．１〜１．０％，Ａｌ１．８〜
２．４％，Ｔｉ２．０〜３．０％，Ｎｂ０．５〜１．５
％を含み、残部は不純物を除き本質的にＦｅからなるこ
とを特徴とするＦｅ−Ｎｉ−Ｃｒ基超耐熱合金。6. C0.08% or less by weight%, Si0.2
% Or less, Mn 0.5% or less, Ni 30 to 45%, Cr1
3.5-16%, Mo 0.1-1.0%, Al 1.8-
2.4%, Ti 2.0 to 3.0%, Nb 0.5 to 1.5
%, And the balance is essentially Fe except for impurities, Fe-Ni-Cr based super heat resistant alloy. 【請求項７】 重量％で５％以下のＣｏを、Ｎｉ＋Ｃｏ
≦４９の範囲で含むことを特徴とする請求項１〜６のい
ずれかに記載のＦｅ−Ｎｉ−Ｃｒ基超耐熱合金。7. A Co content of 5% or less by weight, Ni + Co
The Fe-Ni-Cr based superheat-resistant alloy according to any one of claims 1 to 6, characterized in that it is contained in a range of ≤49. 【請求項８】 原子％で、Ａｌを必須添加とし、さらに
ＩＶａ族およびＶａ族から選ばれる１種または２種以上
の元素が，以下の関係式を満たすことを特徴とする請求
項１〜７のいずれかに記載のＦｅ−Ｎｉ−Ｃｒ基超耐熱
合金。 6.5≦[Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta]≦10.0 0.45≦[Al]/([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])≦0.
758. An atomic percentage of Al is essential addition, and one or more elements selected from the IVa group and the Va group satisfy the following relational expressions. Fe-Ni-Cr based super heat resistant alloy as described in any one of 1. 6.5 ≦ [Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta] ≦ 10.0 0.45 ≦ [Al] / ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta]) ≦ 0.
75 【請求項９】 原子％で、Ａｌを必須添加とし、さらに
ＩＶａ族およびＶａ族から選ばれる１種または２種以上
の元素が，以下の関係式を満たすことを特徴とする請求
項１〜７のいずれかに記載のＦｅ−Ｎｉ−Ｃｒ基超耐熱
合金。 6.5≦[Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta]≦8.5 0.50≦[Al]/([Al]+[Ti]+[Zr]+[Hf]+[V]+[Nb]+[Ta])≦0.
609. At least 1 atomic% of Al is added, and one or more elements selected from the IVa group and the Va group satisfy the following relational expressions: Fe-Ni-Cr based super heat resistant alloy as described in any one of 1. 6.5 ≦ [Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta] ≦ 8.5 0.50 ≦ [Al] / ([Al] + [Ti] + [Zr] + [Hf] + [V] + [Nb] + [Ta]) ≦ 0.
60 【請求項１０】 原子％でＣｒを必須添加とし，さらに
ＭｏおよびＷの１種または２種が、１３≦［Ｃｒ］＋
［Ｍｏ］＋［Ｗ］≦１８の範囲で含まれることを特徴と
する請求項１〜９のいずれかに記載のＦｅ−Ｎｉ−Ｃｒ
基超耐熱合金。10. Cr is essential addition in atomic%, and 1 or 2 kinds of Mo and W are 13 ≦ [Cr] +.
Fe-Ni-Cr according to any one of claims 1 to 9, characterized in that it is contained in a range of [Mo] + [W] ≤18.
Base super heat resistant alloy. 【請求項１１】 重量％で、０．０１５％以下のＢを含
むことを特徴とする請求項１〜１０のいずれかに記載の
Ｆｅ−Ｎｉ−Ｃｒ基超耐熱合金。11. The Fe-Ni-Cr based super heat-resistant alloy according to claim 1, which contains 0.015% or less B by weight. 【請求項１２】 重量％で、０．０２％以下のＭｇと
０．０２％以下のＣａの１種または２種を含むことを特
徴とする請求項１〜１１のいずれかに記載のＦｅ−Ｎｉ
−Ｃｒ基超耐熱合金。12. The Fe- according to any one of claims 1 to 11, characterized in that it contains, by weight, one or two of 0.02% or less of Mg and 0.02% or less of Ca. Ni
-Cr-based super heat resistant alloy. 【請求項１３】 重量％で、０．１％以下のＹと０．１
％以下のＲＥＭの１種または２種を含むことを特徴とす
る請求項１〜１２のいずれかに記載のＦｅ−Ｎｉ−Ｃｒ
基超耐熱合金。13. Y and 0.1 by weight of 0.1% or less.
% Fe or less of 1 or 2 types of REM are contained, Fe-Ni-Cr in any one of Claims 1-12 characterized by the above-mentioned.
Base super heat resistant alloy. 【請求項１４】 ８００℃にて４００時間加熱後の２０
℃におけるＵノッチシャルピー衝撃値が０．５MJ/m²以
上であることを特徴とする請求項１〜１３のいずれかに
記載のＦｅ−Ｎｉ−Ｃｒ基超耐熱合金。14. 20 after heating at 800 ° C. for 400 hours
The Fe-Ni-Cr-based superheat-resistant alloy according to any one of claims 1 to 13, which has a U-notch Charpy impact value at 0.5 ° C of 0.5 MJ / m ² or more. 【請求項１５】 ８００℃にて４００時間加熱後の８０
０℃−２９４ＭＰａにおける回転曲げ疲労試験の破断回
数が０．５×１０⁶回以上であることを特徴とする請求
項１〜１４のいずれかに記載のＦｅ−Ｎｉ−Ｃｒ基超耐
熱合金。15. 80 after heating at 800 ° C. for 400 hours
The Fe-Ni-Cr based super heat-resistant alloy according to any one of claims 1 to 14, wherein the number of times of rupture in a rotary bending fatigue test at 0 ° C-294 MPa is 0.5 × 10 ⁶ or more. 【請求項１６】 請求項１〜１５のいずれかに記載のＦ
ｅ−Ｎｉ−Ｃｒ基超耐熱合金を用いて製造される自動車
用エンジンバルブ。16. The F according to any one of claims 1 to 15.
An engine valve for an automobile manufactured by using an e-Ni-Cr-based superalloy. 【請求項１７】 請求項１〜１５のいずれかに記載のＦ
ｅ−Ｎｉ−Ｃｒ基超耐熱合金を用いて製造される自動車
用排ガス触媒用ニットメッシュ。17. The F according to any one of claims 1 to 15.
A knit mesh for an automobile exhaust gas catalyst manufactured using an e-Ni-Cr-based super heat-resistant alloy.