JPH06200354A - Heat resistant steel for exhaust valve - Google Patents
Heat resistant steel for exhaust valveInfo
- Publication number
- JPH06200354A JPH06200354A JP34953192A JP34953192A JPH06200354A JP H06200354 A JPH06200354 A JP H06200354A JP 34953192 A JP34953192 A JP 34953192A JP 34953192 A JP34953192 A JP 34953192A JP H06200354 A JPH06200354 A JP H06200354A
- Authority
- JP
- Japan
- Prior art keywords
- high temperature
- strength
- fatigue strength
- steel
- strengthening
- 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.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、自動車等の内燃機関の
排気バルブ等の高温部材で、高温強度や高温疲労強度に
優れた耐熱鋼に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat resistant steel which is a high temperature member such as an exhaust valve of an internal combustion engine of an automobile or the like and which is excellent in high temperature strength and high temperature fatigue strength.
【０００２】[0002]
【従来の技術】近年、自動車の燃費向上・高出力化が望
まれ、これに伴い排気ガス温度も９００℃付近にまで上
昇してきている。これまで、自動車ガソリンエンジン等
の排気バルブ用材料としては、２１−４Ｎ鋼（ＳＵＨ３
５：０．５Ｃ−９Ｍｎ−２１Ｃｒ−４Ｎｉ−０．４Ｎ）
が広く用いられてきたが、この鋼は排ガスの高温化に対
応十分な高温強度や高温疲労強度を有してはいない。ま
た、２１−４Ｎの高温強度不足の観点から、ＮＣＦ７５
１等のＮｉ基合金を用いることで対処している場合もあ
るが、８５０℃以上の高温疲労強度はＮＣＦ７５１も２
１−４Ｎとほぼ同レベルであり、かつＮｉ基合金はコス
ト高でもあるため、コスト−性能のバランスが不十分で
ある。また、一部では、排気バルブの温度を下げるため
に、中空化し、Ｎａ封入することで対処している。しか
し、中空化加工はコスト高になり、かつＮａは取扱いが
非常に困難で危険を伴うという問題点がある。2. Description of the Related Art In recent years, it has been desired to improve the fuel efficiency and output of automobiles, and accordingly, the exhaust gas temperature has risen to around 900.degree. Until now, as a material for exhaust valves of automobile gasoline engines, etc., 21-4N steel (SUH3
5: 0.5C-9Mn-21Cr-4Ni-0.4N)
However, this steel does not have sufficient high temperature strength and high temperature fatigue strength to cope with the high temperature of exhaust gas. From the viewpoint of insufficient high temperature strength of 21-4N, NCF75
Although it may be dealt with by using a Ni-based alloy such as No. 1, the high temperature fatigue strength of 850 ° C. or higher is 2 in NCF751.
Since it is almost at the same level as 1-4N and the cost of the Ni-based alloy is also high, the cost-performance balance is insufficient. Further, in some cases, in order to lower the temperature of the exhaust valve, it is dealt with by hollowing and enclosing Na. However, the hollowing process has a problem that the cost is high and Na is very difficult to handle and dangerous.
【０００３】[0003]
【発明が解決しようとする課題】上記のように、従来の
排気バルブ用材料では、排ガスの高温化に対して、高温
特性、特に高温疲労強度の点で不十分な場合や、素材の
高性能化（Ｎｉ基合金の使用）やバルブ材の低温化（中
空バルブ）のために高コストであったり、製品取扱い上
危険を伴うと言った問題をかかえている。本発明は、経
済性を確保しつつ、熱間加工性を劣化させずに高温強度
および高温疲労強度を改善した排気バルブ用耐熱鋼を提
供することを目的としている。すなわち、バルブシート
等の相手部材の材質の変更を最小限にするとともに、経
済性を確保するため２１−４Ｎ鋼を基本成分とし、これ
にＶ、ＭｏあるいはＷを適量添加することで高温強度お
よび高温疲労強度の改善を図るものである。As described above, in the conventional exhaust valve materials, when the exhaust gas temperature is high, the high temperature characteristics, particularly high temperature fatigue strength, are insufficient, and the performance of the material is high. However, there are problems such as high cost (due to use of Ni-based alloy) and low temperature of valve material (hollow valve), and danger in handling the product. An object of the present invention is to provide a heat-resistant steel for exhaust valves, which is economical and secures high-temperature strength and high-temperature fatigue strength without deteriorating hot workability. That is, in order to minimize the change in the material of the mating member such as the valve seat and to ensure the economical efficiency, 21-4N steel is used as a basic component, and V, Mo or W is added thereto in an appropriate amount to obtain high temperature strength and It is intended to improve high temperature fatigue strength.
【０００４】[0004]
【課題を解決するための手段】本発明は、経済性を確保
するという観点から現行の２１−４鋼を基本組成とし、
これの高温強度および高温疲労強度を向上させるため、
析出強化および固溶強化を用いることを基本技術思想と
するもので、第１の発明は、析出強化による高温強度お
よび高温疲労強度の改善を図るべく構成したものであ
る。すなわち、析出強化は、固溶強化に比べ強化量が
大きいこと、析出物の種類によりその強化量や強化の
温度依存性が異なってくることを特に考慮して、Ｖ単独
添加による炭窒化物による析出強化とした。図１〜３に
示すように、従来材である２１−４ＮとＮＣＦ７５１と
を比較すると、全温度域にわたってＮＣＦ７５１が２１
−４Ｎに比べ高強度になっているが、その差は高温にな
るほど小さくなり、９５０℃では両材の高温強度はほぼ
同レベルになってしまう。また、高温疲労強度について
は、やはり低温側では２１−４Ｎに比べＮＣＦ７５１が
高い疲労強度を有しているが、９００℃になると両材の
疲労強度はほぼ同レベルになる。これは、両材の高温強
化機構の違いからくるもので２１−４Ｎが炭窒化物によ
る析出強化であるのに対し、ＮＣＦ７５１はγ′による
析出強化であるためで、γ′の析出強化は炭窒化物の析
出強化に比べ温度依存性が強く、高温になるとγ′の析
出強化は効果が著しく薄れるのである。この点に着目
し、炭窒化物の析出強化＋固溶強化による高温強化を図
った。炭窒化物形成元素の中でも、Ｖの単独添加が最も
効果的であることを見出した。Ｔｉ、Ｎｂ、Ｔａあるい
はＺｒと言った炭窒化物形成元素についても高温強化に
は効果的であるが、Ｖの効果ほどではなく、Ｖとこれら
の複合添加は、Ｖの効果を阻害するものであることを見
出した。これは、Ｖの炭窒化物が高温強化に最も有効で
あり、ＴｉやＮｂの様にＶよりもＣ、Ｎとの親和力が大
きい元素を複合添加するとＶの炭窒化物が析出しにくく
なるめ、Ｖの効果が薄れてしまうのである。したがっ
て、析出強化としてはＶの単独添加による炭窒化物析出
強化にて高温強度および高温疲労強度の改善を図るもの
である。The present invention uses the current 21-4 steel as a basic composition from the viewpoint of ensuring economy.
To improve its high temperature strength and high temperature fatigue strength,
The basic technical idea is to use precipitation strengthening and solid solution strengthening, and the first invention is configured to improve high temperature strength and high temperature fatigue strength by precipitation strengthening. That is, the precipitation strengthening is performed by carbonitride by adding V alone, in consideration of the fact that the strengthening amount is larger than the solid solution strengthening and that the strengthening amount and the temperature dependence of the strengthening differ depending on the type of the precipitate. Precipitation strengthened. As shown in FIGS. 1 to 3, when the conventional material 21-4N and NCF751 are compared, NCF751 is 21% over the entire temperature range.
Although the strength is higher than that of -4N, the difference becomes smaller as the temperature becomes higher, and at 950 ° C, the high temperature strength of both materials becomes almost the same level. Regarding the high temperature fatigue strength, NCF751 has higher fatigue strength than 21-4N on the low temperature side, but at 900 ° C, the fatigue strength of both materials becomes almost the same level. This is due to the difference in the high temperature strengthening mechanism of both materials. While 21-4N is precipitation strengthening by carbonitride, NCF751 is precipitation strengthening by γ ', and precipitation strengthening of γ'is carbon. The temperature dependence is stronger than the precipitation strengthening of nitrides, and the effect of the precipitation strengthening of γ'is significantly diminished at high temperatures. Focusing on this point, we aimed at high temperature strengthening by precipitation strengthening of carbonitride + solid solution strengthening. Among the carbonitride forming elements, it was found that the addition of V alone is the most effective. Carbonitride forming elements such as Ti, Nb, Ta or Zr are also effective for high temperature strengthening, but they are not as effective as V, and V and their combined addition impede the effect of V. I found that there is. This is because carbonitrides of V are most effective for high temperature strengthening, and carbonitrides of V are less likely to precipitate when elements such as Ti and Nb having a greater affinity for C and N than V are added in combination. , V is less effective. Therefore, as precipitation strengthening, carbonitride precipitation strengthening by adding V alone is intended to improve high temperature strength and high temperature fatigue strength.
【０００５】第２の発明は、このような、Ｖの効果を阻
害することなく、さらに強化するための方法としてＭｏ
あるいはＷの単独または複合添加による固溶強化を図ろ
うとするものである。固溶強化元素として７００℃以上
の温度域で固溶量を確保できるＭｏあるいはＷの単独ま
たは複合添加が有効であることを見出した。第３の発明
は、固溶強化は析出強化に比べて長時間安定した高温強
度等を確保できるため高温疲労や長時間クリープに対し
ては有効な強化手法であり、Ｖを添加しない場合、高温
強度および高温疲労強度を向上させる方法として固溶強
化能の高いＭｏあるいはＷの単独または複合添加が特に
高温疲労強度の向上に有効であることを見出したことに
基づくものである。The second invention is Mo as a method for further strengthening the effect of V without impairing the effect of V.
Alternatively, it is intended to achieve solid solution strengthening by adding W alone or in combination. It has been found that Mo or W, which can secure a solid solution amount in a temperature range of 700 ° C. or higher, is effective as a solid solution strengthening element alone or in combination. The third invention is a strengthening method that is effective against high temperature fatigue and long-term creep because solid solution strengthening can secure stable high temperature strength for a long time as compared with precipitation strengthening. This is based on the finding that addition of Mo or W having high solid solution strengthening ability alone or in combination is particularly effective for improving high temperature fatigue strength as a method of improving strength and high temperature fatigue strength.
【０００６】[0006]
【作用】本発明における合金元素の添加量の限定理由を
以下に述べる。 Ｃ：析出強化に必須な添加元素であり、高温強度および
高温疲労強度を確保するために０．３％以上とした。一
方、０．６％を超える添加は、熱間加工性、切削性およ
び常温延性を低下させるためこれを上限とした。The reason for limiting the addition amount of the alloying element in the present invention will be described below. C: Additive element essential for precipitation strengthening, and was set to 0.3% or more in order to secure high temperature strength and high temperature fatigue strength. On the other hand, the addition of more than 0.6% lowers the hot workability, machinability and room temperature ductility, so this was made the upper limit.
【０００７】Ｓｉ：脱酸材として用い、耐酸化性向上に
有効であるため０．１％以上とした。一方、１．０％を
超える添加は常温延性を低下させるためこれを上限とし
た。 Ｍｎ：オーステナイト形成元素であり８．０％以上の添
加が必要である。一方、１１．０％を超える添加は耐酸
化性を阻害するためこれを上限とした。 Ｃｒ：耐酸化性確保のため１９．０％以上とした。ま
た、２５．０％を超える添加は、８００〜９００℃程度
の温度域では、さらなる耐酸化性の向上はなく、これを
上限とした。Si: Used as a deoxidizing material and effective in improving the oxidation resistance, so 0.1% or more. On the other hand, addition of more than 1.0% lowers the room temperature ductility, so this was made the upper limit. Mn: an austenite forming element, and it is necessary to add 8.0% or more. On the other hand, the addition of more than 11.0% impairs the oxidation resistance, so this was made the upper limit. Cr: 19.0% or more to secure oxidation resistance. Further, the addition of more than 25.0% did not further improve the oxidation resistance in the temperature range of about 800 to 900 ° C., and this was made the upper limit.
【０００８】Ｎｉ：オーステナイト形成元素であり、耐
熱性向上に有効であるため３．０％以上とした。しか
し、１０．０％を超える添加は、オーステナイト安定性
や耐熱性向上の寄与率が小さくなるため、これを上限と
した。 Ｖ：析出強化による高温強度および高温疲労強度の改善
に不可欠な元素である。Ｖの炭窒化物は、他の炭窒化物
に比べ比較的高温長時間に亙って安定であるため、高温
強度および高温疲労強度を向上させるために有効な析出
物である。一方、過剰添加は熱間加工性および常温延性
の低下を招くため、高温強度および高温疲労強度と熱間
加工性および常温延性の観点から、単独添加の場合（請
求項１）０．３〜１．０％とした。また、固溶強化元素
であるＭｏおよび／またはＷとの複合添加の場合（請求
項２）には、Ｍｏおよび／またはＷの添加も熱間加工性
を劣化させるため、Ｖ単独添加の場合より低い添加量に
する必要があり、０．１〜０．７％とした。Ni: An austenite forming element, which is effective for improving heat resistance, and is therefore set to 3.0% or more. However, the addition of more than 10.0% has a small contribution to the improvement of austenite stability and heat resistance, so this was made the upper limit. V: An element essential for improving high temperature strength and high temperature fatigue strength by precipitation strengthening. The carbonitride of V is more stable than other carbonitrides at a relatively high temperature for a long time, and thus is an effective precipitate for improving high temperature strength and high temperature fatigue strength. On the other hand, since excessive addition causes deterioration of hot workability and room temperature ductility, from the viewpoint of high temperature strength and high temperature fatigue strength, hot workability and room temperature ductility, in the case of single addition (claim 1) 0.3 to 1 It was set to 0.0%. Further, in the case of composite addition with Mo and / or W which are solid solution strengthening elements (claim 2), since addition of Mo and / or W also deteriorates hot workability, it is more than the case of V alone addition. It is necessary to make the addition amount low, and it is 0.1 to 0.7%.
【０００９】Ｎ：析出強化に必須な添加元素であり、高
温強度および高温疲労強度を確保するために０．３％以
上とした。一方、０．６％を超える添加は、熱間加工
性、切削性および常温延性を低下させるため、これを上
限とした。 Ｍｏ：固溶強化による高温強度および高温疲労強度の改
善に不可欠な元素である。固溶強化は析出強化に比べそ
の強化量は小さいものの長時間安定性に優れている。一
方、過剰添加は熱間加工性を著しく低下させる。このた
め、高温強度および高温疲労強度と熱間加工性および常
温延性との両立の観点から、Ｖ無添加の場合である請求
項３では１．０〜５．０％、Ｖとの複合添加の場合であ
る請求項２では０．５〜５．０％とした。また、Ｗと複
合で、Ｖ無添加の場合１．０％≦Ｍｏ＋Ｗ≦７．０％と
し、Ｖ添加の場合０．５％≦Ｍｏ＋Ｗ≦５．０％とし
た。N: An additional element essential for precipitation strengthening, and is set to 0.3% or more in order to secure high temperature strength and high temperature fatigue strength. On the other hand, the addition of more than 0.6% lowers the hot workability, machinability and room temperature ductility, so this was made the upper limit. Mo: An element essential for improving high temperature strength and high temperature fatigue strength by solid solution strengthening. Although solid solution strengthening is smaller than precipitation strengthening, it is superior in long-term stability. On the other hand, excessive addition significantly reduces hot workability. Therefore, from the viewpoint of compatibility of high temperature strength and high temperature fatigue strength with hot workability and room temperature ductility, V is not added. In claim 3, 1.0 to 5.0% of V is added in combination. In the case of claim 2, which is the case, it is set to 0.5 to 5.0%. In addition, in the case where V is not added and composite with W, 1.0% ≦ Mo + W ≦ 7.0%, and when V is added, 0.5% ≦ Mo + W ≦ 5.0%.
【００１０】Ｗ：固溶強化による高温強度および高温疲
労強度の改善に不可欠な元素である。固溶強化は析出強
化に比べその強化量は小さいものの長時間安定性に優れ
ている。一方、過剰添加は熱間加工性を著しく低下させ
る。このため、高温強度および高温疲労強度と熱間加工
性および常温延性との両立の観点から、Ｖ無添加の場合
である請求項３では１．０〜５．０％、Ｖとの複合添加
の場合である請求項２では０．５〜５．０％とした。ま
た、Ｍｏと複合で、Ｖ無添加の場合１．０％≦Ｍｏ＋Ｗ
≦７．０％とし、Ｖ添加の場合０．５％≦Ｍｏ＋Ｗ≦
５．０％とした。W: An element essential for improving high temperature strength and high temperature fatigue strength by solid solution strengthening. Although solid solution strengthening is smaller than precipitation strengthening, it is superior in long-term stability. On the other hand, excessive addition significantly reduces hot workability. Therefore, from the viewpoint of compatibility of high temperature strength and high temperature fatigue strength with hot workability and room temperature ductility, V is not added. In claim 3, 1.0 to 5.0% of V is added in combination. In the case of claim 2, which is the case, it is set to 0.5 to 5.0%. In addition, when it is composite with Mo and V is not added, 1.0% ≦ Mo + W
≦ 7.0%, with V added 0.5% ≦ Mo + W ≦
It was set to 5.0%.
【００１１】高温強度および高温疲労強度：９００℃の
引張り強度で２３ｋｇｆ／ｍｍ2 より高く、９００℃の
回転曲げ疲労強度が１５ｋｇｆ／ｍｍ2 よりも高いこと
を満たすため、上記化学成分のようにＶ、Ｍｏあるいは
Ｗを単独または複合添加することで達成させるものであ
る。[0011] high-temperature strength and high temperature fatigue strength: in tensile strength of 900 ° C. higher than 23kgf / mm 2, since the rotary bending fatigue strength of 900 ° C. satisfies higher than 15kgf / mm 2, V as above chemical components , Mo or W is added alone or in combination.
【００１２】[0012]
【実施例】表１に本発明鋼および比較鋼の化学成分を、
表２に供試鋼の熱間加工性と材質特性をそれぞれ示す。
なお、供試鋼は、真空溶製後、熱間鍛造し、１１７５℃
にて固溶化処理した後、７６０℃×４時間保定後、空冷
の時効を施し、各種試験片を採取した。EXAMPLES Table 1 shows the chemical composition of the steels of the present invention and comparative steels.
Table 2 shows the hot workability and material properties of the test steels.
The test steel was vacuum-melted and then hot forged at 1175 ° C.
After being subjected to a solution treatment at 760 ° C., it was held at 760 ° C. for 4 hours, and then air-cooled aging was performed to collect various test pieces.
【００１３】表２に示すように、Ｖの単独添加（請求項
１）で１．０％を超えて添加したＪ鋼は、熱間加工性が
良好でなく、鍛造時に表面割れが発生し、試験片採取が
一応できる程度である。また、常温延性も１０％を切る
値で、Ｖの過剰添加は熱間加工性および常温延性ともに
劣化させる。また、高温強度および高温疲労強度を０．
８７％のＶを添加したＢ鋼と比較すると、大きな差はな
く、Ｖを１％を超えて添加しても高温強度および高温疲
労強度のさらなる向上はない。また、Ａ鋼と２１−４Ｎ
鋼の比較から、Ｖは０．３％以上添加することで高温強
度および高温疲労強度が確保できることがわかる。As shown in Table 2, J steel added with V alone (claim 1) in an amount of more than 1.0% does not have good hot workability and surface cracking occurs during forging. The test pieces can be collected for the time being. Further, the room temperature ductility is a value less than 10%, and excessive addition of V deteriorates both hot workability and room temperature ductility. Further, the high temperature strength and the high temperature fatigue strength are 0.
Compared to B steel with 87% V added, there is no significant difference, and addition of V in excess of 1% does not further improve high temperature strength and high temperature fatigue strength. Also, A steel and 21-4N
From the comparison of steels, it can be seen that addition of 0.3% or more of V can secure high temperature strength and high temperature fatigue strength.
【００１４】ＭｏおよびＷとＶを複合添加する（請求項
２）と、Ｃ〜Ｅ鋼と２１−４Ｎ鋼との比較から、高温強
度および高温疲労強度が改善され、常温の延性も確保で
きることがわかる。一方、Ｋ鋼の例からわかるように、
Ｍｏが５％を超えると、また、Ｍｏ＋Ｗで５％を超える
と熱間加工性が劣化し、鍛造時に割れが多発してしま
う。さらにＶについてもＭ鋼の例からわかる通り、Ｍｏ
やＷと複合添加する場合は０．７％を超えると熱間加工
性が劣化してしまう。When Mo and W and V are added in combination (claim 2), the high temperature strength and the high temperature fatigue strength are improved and the ductility at room temperature can be ensured by comparing the C to E steels and the 21-4N steel. Recognize. On the other hand, as can be seen from the example of K steel,
If Mo exceeds 5%, or if Mo + W exceeds 5%, hot workability deteriorates, and cracks frequently occur during forging. As for V, as seen from the example of M steel, Mo
In the case where it is added together with or W, if it exceeds 0.7%, the hot workability deteriorates.
【００１５】ＭｏやＷを添加（請求項３）すると、Ｆ〜
Ｈ鋼の例からわかるように２１−４Ｎに比べ高温強度お
よび高温疲労強度が改善され、常温の延性も確保でき
る。しかし、Ｌ鋼の例からわかるように、Ｗが５％を超
えると、またＭｏ＋Ｗで７％を超えると熱間加工性が劣
化し、鍛造時に割れが多発してしまう。Ｍｏ、Ｗあるい
はＶを添加してもＴｉあるいはＮｂを添加してしまう
と、Ｏ鋼とＤ鋼、Ｎ鋼とＡ鋼とをそれぞれ比較すること
でわかるように、２１−４Ｎに比べ高温強度および高温
疲労強度を改善することはできるが、ＴｉあるいはＮｂ
を添加しない方がその改善効果が大きいことがわかる。When Mo or W is added (claim 3), F to
As can be seen from the example of H steel, the high temperature strength and high temperature fatigue strength are improved as compared with 21-4N, and the ductility at room temperature can be secured. However, as can be seen from the example of L steel, when W exceeds 5%, and when Mo + W exceeds 7%, the hot workability deteriorates and cracks frequently occur during forging. If Ti or Nb is added even if Mo, W, or V is added, as can be seen by comparing O steel and D steel, and N steel and A steel, respectively, high temperature strength and 21 High temperature fatigue strength can be improved, but Ti or Nb
It can be seen that the improvement effect is more significant when no is added.
【００１６】[0016]
【表１】 [Table 1]
【００１７】[0017]
【表２】 [Table 2]
【００１８】[0018]
【発明の効果】本発明に従った鋼は、排ガスの高温化に
対応可能な高温強度および高温疲労強度を有する。即
ち、本発明は、９００℃における高温引張り強度が２３
ｋｇｆ／ｍｍ2 より高く、かつ９００℃における回転曲
げ疲労強度が１６ｋｇｆ／ｍｍ2より高く、経済性およ
び熱間加工性を確保できる排気バルブ用耐熱鋼を提供で
きる。The steel according to the present invention has high-temperature strength and high-temperature fatigue strength that can cope with the high temperature of exhaust gas. That is, the present invention has a high temperature tensile strength of 23 at 900 ° C.
higher than kgf / mm 2, and higher rotating bending fatigue strength than 16 kgf / mm 2 at 900 ° C., can provide economical and hot workability can be ensured exhaust valve for heat-resistant steels.
【図１】ＮＣＦ７５１、２１−４Ｎ鋼および本発明鋼の
９００℃の高温引張り強度と疲労強度との関係を示す図
である。FIG. 1 is a diagram showing the relationship between high temperature tensile strength at 900 ° C. and fatigue strength of NCF751, 21-4N steel and steel of the present invention.
【図２】ＮＣＦ７５１および２１−４Ｎ鋼の高温引張り
強度と試験温度の関係を示す図である。FIG. 2 is a diagram showing the relationship between high temperature tensile strength and test temperature of NCF751 and 21-4N steel.
【図３】ＮＣＦ７５１および２１−４Ｎ鋼の高温疲労特
性を示す図である。FIG. 3 is a diagram showing high temperature fatigue properties of NCF751 and 21-4N steel.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 山中 幹雄 千葉県富津市新富20−１ 新日本製鐵株式 会社技術開発本部内 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mikio Yamanaka 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation Corporate Technology Development Division
Claims (3)
り、９００℃における高温引張り強度が２３ｋｇｆ／ｍ
ｍ2 より高く、かつ９００℃の回転曲げ疲労強度が１６
ｋｇｆ／ｍｍ2 より高い排気バルブ用耐熱鋼。1. C .: 0.3 to 0.6% Si: 0.1 to 1.0% Mn: 8.0 to 11.0% Cr: 19.0 in weight% (hereinafter abbreviated as%) 25.0% Ni: 3.0 to 10.0% V: 0.3 to 1.0% N: 0.3 to 0.6% with the balance being Fe and inevitable impurities, 900 High temperature tensile strength at 23 ℃ is 23kgf / m
m 2 and a bending fatigue strength at 900 ° C of 16
Heat-resistant steel for exhaust valves with higher than kgf / mm 2 .
を満たす範囲で含み、残部がＦｅおよび不可避的不純物
からなり、９００℃における高温引張り強度が２３ｋｇ
ｆ／ｍｍ2 より高く、かつ９００℃の回転曲げ疲労強度
が１６ｋｇｆ／ｍｍ2 より高い排気バルブ用耐熱鋼。2. C .: 0.3 to 0.6% Si: 0.1 to 1.0% Mn: 8.0 to 11.0% Cr: 19.0 to 25.0% Ni: 3.0 to 10.0% V: 0.1 to 0.7% N: 0.3 to 0.6%, Mo: 0.5 to 5.0% W: 0.5 to 5 0.0% of at least one of 0.5% ≦ Mo + W ≦ 5.0%
Satisfying the requirement, the balance consists of Fe and unavoidable impurities, and the high temperature tensile strength at 900 ° C is 23 kg.
Heat-resistant steel for exhaust valves that has a bending bending fatigue strength at 900 ° C higher than 16 kgf / mm 2 and higher than f / mm 2 .
を満たす範囲で含み、残部がＦｅおよび不可避的不純物
からなり、９００℃における高温引張り強度が２３ｋｇ
ｆ／ｍｍ2 より高く、かつ９００℃の回転曲げ疲労強度
が１６ｋｇｆ／ｍｍ2 より高い排気バルブ用耐熱鋼。3. C: 0.3 to 0.6% Si: 0.1 to 1.0% Mn: 8.0 to 11.0% Cr: 19.0 to 25.0% Ni: 3.0 to 10.0% N: 0.3 to 0.6%, Mo: 1.0 to 5.0% W: 1.0 to 5.0% at least one or more 0.0% ≦ Mo + W ≦ 7.0%
Satisfying the requirement, the balance consists of Fe and unavoidable impurities, and the high temperature tensile strength at 900 ° C is 23 kg.
Heat-resistant steel for exhaust valves that has a bending bending fatigue strength at 900 ° C higher than 16 kgf / mm 2 and higher than f / mm 2 .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34953192A JPH06200354A (en) | 1992-12-28 | 1992-12-28 | Heat resistant steel for exhaust valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34953192A JPH06200354A (en) | 1992-12-28 | 1992-12-28 | Heat resistant steel for exhaust valve |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06200354A true JPH06200354A (en) | 1994-07-19 |
Family
ID=18404357
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34953192A Pending JPH06200354A (en) | 1992-12-28 | 1992-12-28 | Heat resistant steel for exhaust valve |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06200354A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0810294A1 (en) * | 1996-05-24 | 1997-12-03 | TRW Deutschland GmbH | Heat treatable stainless steel for combustion engine valves |
| US8137634B2 (en) * | 2002-07-25 | 2012-03-20 | Uhde Gmbh | Fission reactor for a Claus plant |
| WO2015141331A1 (en) * | 2014-03-19 | 2015-09-24 | 株式会社リケン | Valve seat constituted of iron-based sintered alloy |
-
1992
- 1992-12-28 JP JP34953192A patent/JPH06200354A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0810294A1 (en) * | 1996-05-24 | 1997-12-03 | TRW Deutschland GmbH | Heat treatable stainless steel for combustion engine valves |
| US8137634B2 (en) * | 2002-07-25 | 2012-03-20 | Uhde Gmbh | Fission reactor for a Claus plant |
| WO2015141331A1 (en) * | 2014-03-19 | 2015-09-24 | 株式会社リケン | Valve seat constituted of iron-based sintered alloy |
| JP2015178650A (en) * | 2014-03-19 | 2015-10-08 | 株式会社リケン | Iron-based sinter alloy valve sheet |
| US10233793B2 (en) | 2014-03-19 | 2019-03-19 | Kabushiki Kaisha Riken | Valve seat of sintered iron-based alloy |
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