JP5373147B2 - Steam turbine rotor, Ni-based forged alloy, boiler tube for steam turbine plant - Google Patents
Steam turbine rotor, Ni-based forged alloy, boiler tube for steam turbine plant Download PDFInfo
- Publication number
- JP5373147B2 JP5373147B2 JP2012095206A JP2012095206A JP5373147B2 JP 5373147 B2 JP5373147 B2 JP 5373147B2 JP 2012095206 A JP2012095206 A JP 2012095206A JP 2012095206 A JP2012095206 A JP 2012095206A JP 5373147 B2 JP5373147 B2 JP 5373147B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- phase
- steam turbine
- forged alloy
- based forged
- 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.)
- Expired - Fee Related
Links
Images
Abstract
Description
本発明は、Ｎｉ基鍛造合金、及びこれを含む部材に関する。 The present invention relates to a Ni-based forged alloy and a member including the same .
蒸気タービン，ガスタービン等の発電効率を向上させるためには、主蒸気温度あるいは燃焼温度の向上が有効である。 In order to improve the power generation efficiency of a steam turbine, a gas turbine, etc., it is effective to improve the main steam temperature or the combustion temperature.
主蒸気温度あるいは燃焼温度の向上に伴い、高温部品の温度が高くなるため、より耐用温度の高い耐熱材料が必要となる。 As the main steam temperature or the combustion temperature increases, the temperature of the high-temperature parts increases, so that a heat-resistant material having a higher durability temperature is required.
高温部品は、さらされる温度および部品のサイズにより、精密鋳造材と鍛造材に分類される。小型で使用温度の高いガスタービンの動翼や静翼は、精密鋳造で製作されるのが一般的であるが、大型品を精密鋳造で作製することは困難であることからその他の大型の部材は鍛造で製作されるのが一般的である。 High temperature parts are classified into precision castings and forgings according to the temperature exposed and the size of the parts. Small and high operating temperature turbine blades and stationary blades of gas turbines are generally manufactured by precision casting, but it is difficult to manufacture large products by precision casting. Is generally manufactured by forging.
鍛造品は、１０００℃〜１２００℃の範囲で熱間鍛造を行い成型されるが、この温度域での加工性を確保するためには、１０００℃以上での変形抵抗が小さい必要がある。 The forged product is molded by hot forging in the range of 1000 ° C. to 1200 ° C., but in order to ensure the workability in this temperature range, the deformation resistance at 1000 ° C. or higher needs to be small.
γ′相（Ｎｉ3Ａｌ）により析出強化されたＮｉ基超合金は、高温強度に優れるため、鍛造で製作される高温部品に広く用いられている。γ′相は、低温で高温より安定であり、温度を上げると消失する特性を有する。γ′相が、析出した状態では熱間加工性が悪いため、熱間加工はγ′相が消失する温度（固溶温度）以上で行う必要がある。 Ni-base superalloys precipitation strengthened by the γ ′ phase (Ni 3 Al) are excellent in high-temperature strength and are widely used in high-temperature parts manufactured by forging. The γ ′ phase has a characteristic that it is more stable at a low temperature than at a high temperature and disappears when the temperature is raised. Since the hot workability is poor when the γ ′ phase is precipitated, it is necessary to perform the hot work at a temperature higher than the temperature at which the γ ′ phase disappears (solid solution temperature).
使用温度での強度は、γ′相の析出量が多いほど強くなるためγ′相の析出量を増やす必要があるが、γ′相の析出量を増やすと固溶温度も上昇するため熱間加工が困難になる。 The strength at the working temperature increases as the amount of precipitation of the γ 'phase increases, so it is necessary to increase the amount of precipitation of the γ' phase. However, increasing the amount of precipitation of the γ 'phase increases the solid solution temperature, so Processing becomes difficult.
このため、γ′相強化型鍛造材の高温強度には限界があった。 For this reason, the high temperature strength of the γ 'phase strengthened die forging has a limit.
必要な１０万時間破断強度を１００ＭＰａとした場合、γ′相の固溶温度を１０００℃以下とし、十分な熱間加工性を確保した場合の鍛造材の耐用温度は７５０℃程度が限界であった。 When the required 100,000-hour breaking strength is 100 MPa, the solid solution temperature of the γ ′ phase is set to 1000 ° C. or less, and when the sufficient hot workability is ensured, the forging temperature is limited to about 750 ° C. It was.
また、７５０℃以上では、酸化が顕著となり始めるため、耐用温度を７５０℃以上に高めるためには耐酸化性の向上も不可欠である。耐酸化性を高めるためには、安定な酸化物を形勢するＡｌの添加が有効であるが、Ａｌはγ′相の固溶温度を高め、熱間加工性を悪化させるため、従来の鍛造合金では３wt.％以下であり、Ａｌ酸化物を安定に形成するためには不十分であった。 Further, since oxidation starts to become remarkable at 750 ° C. or higher, improvement of oxidation resistance is indispensable for increasing the service temperature to 750 ° C. or higher. In order to increase the oxidation resistance, it is effective to add Al that forms a stable oxide. However, Al increases the solid solution temperature of the γ 'phase and deteriorates hot workability. Is 3 wt.% Or less, which is insufficient for stably forming an Al oxide.
なお、γ′相を高温まで安定化し、強度を高めるため従来のＮｉ基鍛造合金ではＮｂ，Ｔｉ，Ｔａは不可欠な添加元素とされている（特許文献１参照）。 In addition, in order to stabilize the γ 'phase to a high temperature and increase the strength, Nb, Ti, Ta are considered as indispensable additive elements in the conventional Ni-based forged alloy (see Patent Document 1).
従来の技術を説明したが、これら従来の技術では、熱間加工性と高温強度とを十分に確保することは困難であった。 Although the conventional techniques have been described, it has been difficult to secure sufficient hot workability and high temperature strength with these conventional techniques.
そこで、本発明は、熱間加工性を維持しつつ、耐用温度を７６０〜８００℃に向上させることを目的とする。 Therefore, an object of the present invention is to improve the service temperature to 760 to 800 ° C. while maintaining hot workability.
すなわち、本発明は、従来材と同等の熱間加工性を維持しつつ、耐用温度を従来材の限界である７５０℃から７６０〜８００℃に向上させることである。 That is, the present invention is to improve the service temperature from 750 ° C., which is the limit of the conventional material, to 760 to 800 ° C. while maintaining the hot workability equivalent to that of the conventional material.
また、表面にＡｌ皮膜を形成させることで、この温度域で十分な耐酸化性を確保する。
発明者らはこのような目的を達成させるために、高温でγ′相を不安定にし、低温でγ′相を安定化する合金元素の添加バランスについて検討し、熱間加工性を損なうことなく、耐用温度を大幅に向上させることが可能な添加元素のバランスを見出した。
Further, by forming an Al film on the surface, sufficient oxidation resistance is secured in this temperature range.
In order to achieve such an object, the inventors examined the addition balance of alloy elements that make the γ ′ phase unstable at high temperatures and stabilize the γ ′ phase at low temperatures, without impairing hot workability. The balance of additive elements that can significantly improve the service temperature was found.
つまり、本発明のＮｉ基鍛造合金は、０.００１〜０.１wt.％のＣ、１２〜２３wt.％のＣｒ、３.５〜５.０wt.％のＡｌ、および不可避的不純物を含み、残部がＮｉからなるものであって、ＷとＭｏとの和が５〜１２wt.％、Ｍｏが５wt.％以下、Ｔｉ，Ｔａ，Ｎｂの
添加量が実質的にゼロであることを特徴とする。
That is, the Ni-based forged alloy of the present invention contains 0.001 to 0.1 wt.% C, 12 to 23 wt.% Cr, 3.5 to 5.0 wt.% Al, and inevitable impurities. The balance is made of Ni, the sum of W and Mo is 5 to 12 wt.%, Mo is 5 wt.% Or less, and the addition amount of Ti, Ta, and Nb is substantially zero. .
また、ＷとＭｏとの和が５〜１２wt.％、Ｍｏが５wt.％以下、Ｗ及びＭｏ以外の耐火元素の総和が１wt.％以下、Ｔｉ，Ｔａ，Ｎｂの総和が０.５wt.％以下であることを特徴とする。 Also, the sum of W and Mo is 5 to 12 wt.%, Mo is 5 wt.% Or less, the sum of refractory elements other than W and Mo is 1 wt.% Or less, and the sum of Ti, Ta and Nb is 0.5 wt.%. It is characterized by the following.
そして、固溶温度が１０００℃以下であり、７５０℃における１０5ｈクリープ破断強度が１００ＭＰａ以上、平均粒径が５０〜１００ｎｍであるＮｉ3Ａｌ相が、７００℃以下で、体積率で３０％以上析出し、Ｃの含有量が０.００１〜０.０４wt.％であることが好ましい。 The Ni 3 Al phase having a solid solution temperature of 1000 ° C. or less, a 10 5 h creep rupture strength at 750 ° C. of 100 MPa or more, and an average particle size of 50 to 100 nm is 700 ° C. or less and 30% by volume. Precipitating as described above, it is preferable that the C content is 0.001 to 0.04 wt.%.
また、これらＮｉ基鍛造合金は、蒸気タービンプラント用鍛造部品として用いられる。 These Ni-based forged alloys are used as forged parts for steam turbine plants.
特に、主蒸気温度７２０℃以上の蒸気タービンプラント用ボイラチューブ、使用温度が７５０℃以上となる蒸気タービンプラント用ボルト、環境温度が７５０℃以上となる蒸気タービンロータに使用されることが好ましい。 In particular, it is preferably used for a steam turbine plant boiler tube having a main steam temperature of 720 ° C. or higher, a steam turbine plant bolt having a use temperature of 750 ° C. or higher, and a steam turbine rotor having an environmental temperature of 750 ° C. or higher.
本発明により、熱間加工性を維持しつつ、耐用温度を７６０〜８００℃に向上させることが可能となる。 According to the present invention, it is possible to improve the service temperature to 760 to 800 ° C. while maintaining hot workability.
まず、本発明の添加元素のバランス、すなわち有効な化学成分範囲およびその根拠を以下に示す。 First, the balance of additive elements of the present invention, that is, the effective chemical component range and the basis thereof will be shown below.
Ｃｒは、耐食性を確保する上で重要な元素であり、１５wt.％以上の添加が必要であるが、過剰に添加すると、脆化相としてしられるσ相が析出するため２３wt.％以下とする必要がある。 Cr is an important element for ensuring corrosion resistance and needs to be added in an amount of 15 wt.% Or more. However, if added excessively, the σ phase, which becomes an embrittled phase, is precipitated, so the content is 23 wt.% Or less. There is a need.
しかし、これらの元素は耐酸化性を悪化させ、特に加工温度付近の高温ではγ′相を安定化し高強度化するが使用温度付近ではγ′相の安定化に寄与しないことから、強度と熱間加工性を両立させることを目指した超合金においては、熱間加工性の観点からも添加しないことが望ましい。この点で本発明は従来の合金設計思想と異なる。 However, these elements deteriorate the oxidation resistance and stabilize the γ 'phase at a high temperature near the processing temperature and increase its strength, but do not contribute to the stabilization of the γ' phase near the working temperature. In a superalloy aiming to achieve both hot workability, it is desirable not to add from the viewpoint of hot workability. In this respect, the present invention differs from the conventional alloy design concept.
Ａｌは、γ′相を安定化し強度を高め耐酸化性を向上させる。耐酸化性の観点からは３.５wt.％、強度の観点からは４wt.％以上の添加が望ましい。しかし、Ａｌを５wt.％以上添加するとγ′相の固溶温度が上昇し熱間加工が困難となる。 Al stabilizes the γ ′ phase, increases strength, and improves oxidation resistance. It is desirable to add 3.5 wt.% From the viewpoint of oxidation resistance and 4 wt.% Or more from the viewpoint of strength. However, when Al is added in an amount of 5 wt.% Or more, the solid solution temperature of the γ 'phase increases and hot working becomes difficult.
Ｎｉと類似した特徴をもつＣｏはγ′相を不安定にする。すなわち、γ′相の固溶温度を下げるため、熱間加工下限温度を低くして熱間加工を容易にする。より高い耐酸化性を求める場合、Ｃｏを１５wt.％以上添加することが望ましい。しかし、Ｃｏは有害相であるσ相を安定にすることから、２３wt.％以下にする必要がある。γ′相が析出するマトリックスについても、固溶強化する必要があり、また、高温でのγ′相の粗大化を押させるためには拡散係数を下げる必要がある。 Co having characteristics similar to Ni destabilizes the γ 'phase. That is, in order to lower the solid solution temperature of the γ ′ phase, the hot working lower limit temperature is lowered to facilitate hot working. When higher oxidation resistance is required, it is desirable to add 15 wt.% Or more of Co. However, since Co stabilizes the σ phase, which is a harmful phase, it must be 23 wt.% Or less. The matrix on which the γ ′ phase is precipitated also needs to be strengthened by solid solution, and the diffusion coefficient needs to be lowered in order to suppress the coarsening of the γ ′ phase at a high temperature.
このためには、Ｍｏ，Ｗ，Ｒｅなどの耐火元素を添加する必要がある。ＭｏおよびＲｅなどＷ以外の耐火元素は、凝固時に液相または固相に濃化し偏析欠陥の生成を助長することから添加元素としては望ましくなく、Ｗの添加が好ましい。上記の効果を得るためにはＷを５wt.％以上添加することが望ましい。 For this purpose, it is necessary to add refractory elements such as Mo, W, and Re. Refractory elements other than W such as Mo and Re are not desirable as additive elements because they concentrate in the liquid phase or solid phase during solidification and promote the generation of segregation defects, and the addition of W is preferable. In order to obtain the above effect, it is desirable to add 5 wt.% Or more of W.
しかし、Ｗは有害相であるσ相やμ相を安定化する。また、固溶強化は高温まで維持されγ′相固溶温度以上でも熱間加工性に悪影響を与えることから、Ｗの添加量は１２wt.％以下とする必要がある。 However, W stabilizes the σ phase and μ phase, which are harmful phases. Further, since solid solution strengthening is maintained up to a high temperature and the hot workability is adversely affected even at a temperature higher than the γ ′ phase solid solution temperature, the amount of W needs to be 12 wt.% Or less.
Ｍｏは、前記のように偏析元素であるが、強度，相安定性に与える影響はＷと類似しており、５wt.％まではＷに置き換えて添加することができる。 As described above, Mo is a segregating element, but its influence on strength and phase stability is similar to that of W, and up to 5 wt.
以上述べた思想により構成される本発明材は、優れたクリープ強度と耐酸化性を示しながらもNimonic２６３などの従来鍛造合金と同様に熱間加工が可能である。１０万時間クリープ破断強度は７５０℃において１００ＭＰａ以上を示し、高温酸化処理で酸化保護皮膜であるＡｌ酸化物が自己形成されることが本発明材の特徴である。このような、合金は従来は熱間鍛造が困難であり、精密鋳造にて製造する必要があったが、本発明により鍛造を可能とした。 The material of the present invention constituted by the above-described idea can be hot-worked in the same manner as conventional forged alloys such as Nimonic 263 while exhibiting excellent creep strength and oxidation resistance. The 100,000-hour creep rupture strength is 100 MPa or more at 750 ° C., and it is a feature of the material of the present invention that Al oxide as an oxidation protective film is self-formed by high-temperature oxidation treatment. Such an alloy is conventionally difficult to hot forge and must be manufactured by precision casting, but the present invention enables forging.
表１に供試材の化学成分を示す。なお、表中、Ｃ又はＳで始まる材料名のものは従来材と位置づけた。 Table 1 shows chemical components of the test materials. In the table, materials having material names beginning with C or S were regarded as conventional materials.
供試材高周波溶解により作製し、鍛造可能な合金については鍛造し、不可能な成分については、精密鋳造により試料を作製した。 Samples were prepared by high frequency melting, forged alloys that could be forged, and specimens were fabricated by precision casting for the impossible components.
図１は、これらの合金のγ′相固溶温度と７００℃でのγ′相析出量（面積率）の関係を示す。γ′相の固溶温度については、熱示差分析により決定することができる。熱示差分析では、溶体化時効処理によりγ′相を析出させた後、試料を昇温さ、γ′相が固溶する際の反応熱が検知される温度をもとに固溶温度を決定する。 FIG. 1 shows the relationship between the γ ′ phase solid solution temperature of these alloys and the amount of γ ′ phase precipitation (area ratio) at 700 ° C. The solid solution temperature of the γ ′ phase can be determined by thermal differential analysis. In thermal differential analysis, after precipitation of the γ 'phase by solution aging, the temperature of the sample is raised, and the solution temperature is determined based on the temperature at which the heat of reaction is detected when the γ' phase is dissolved. To do.
７００℃でのγ′相析出量は供試材を７００℃において長時間時効した後、ＳＥＭ観察を行いＳＥＭ像について画像解析を行い決定することができる。時効時間は４８時間前後が適当である。 The amount of γ ′ phase precipitation at 700 ° C. can be determined by aging the specimen at 700 ° C. for a long time, and then performing SEM observation and image analysis on the SEM image. A proper aging time is around 48 hours.
図１に示すように従来材では、γ′相固溶温度が高いほど７００℃でのγ′相析出量が多くなり、γ′相の析出強化が強くなり、より高強度となる。γ′相は熱間加工性を著しく阻害することから熱間加工温度は、γ′相固溶温度よりも高い必要があるため、高強度な材料ほど熱間加工が困難であり、γ′相固溶温度が１０５０℃を超えると実質的に鍛造困難となり、鍛造材としてではなく、鋳造材として用いられる。 As shown in FIG. 1, in the conventional material, the higher the γ ′ phase solid solution temperature, the greater the amount of γ ′ phase precipitation at 700 ° C., the stronger the precipitation strengthening of the γ ′ phase, and the higher the strength. Since the γ 'phase significantly hinders hot workability, the hot working temperature needs to be higher than the γ' phase solution temperature. When the solid solution temperature exceeds 1050 ° C., it becomes difficult to forge substantially, and it is used not as a forging material but as a casting material.
鋳造材は鋳造欠陥の観点から大型品の製造は困難であり、大型品の製造には鍛造材が適しているが、従来の知見では鍛造材では７００℃において析出せることができるγ′相の量の上限は２５％程度である。 Casting materials are difficult to manufacture in terms of casting defects, and forgings are suitable for manufacturing large items. However, according to conventional knowledge, forgings have a γ ′ phase that can be precipitated at 700 ° C. The upper limit of the amount is about 25%.
図１に示すように本発明材では、γ′相の固溶温度が１０００℃程度であっても、７００℃で３５％以上のγ′相を析出させることができ従来の鍛造材より大幅に高温強度を向上させるポテンシャルを有することを示す。 As shown in FIG. 1, in the material of the present invention, even if the solid solution temperature of the γ ′ phase is about 1000 ° C., 35% or more of the γ ′ phase can be precipitated at 700 ° C. It has the potential to improve high temperature strength.
図２に、本発明材および従来材の温度とγ′相析出量の関係を示す。本発明材では従来材と同様にγ′相固溶温度を鍛造材料の加工温度以下としながらも使用温度である７００〜８００℃において、従来材と比較して多くのγ′相が析出する成分である。 FIG. 2 shows the relationship between the temperature of the inventive material and the conventional material and the amount of γ ′ phase precipitation. In the material of the present invention, the γ ′ phase solid solution temperature is equal to or lower than the processing temperature of the forging material as in the case of the conventional material, but at a use temperature of 700 to 800 ° C., a component in which more γ ′ phase is precipitated compared to the conventional material. It is.
ＣＯＮ２２２は、γ′相の固溶温度が１０００℃以上であるために熱間加工が困難であり、精密鋳造材としてガスタービンの静翼などに用いられる成分であり、８００℃における１０万時間クリープ破断強度は１００ＭＰａ程度である。発明材のγ′相固溶温度は従来の鍛造合金と同等であるにも関わらず、７００〜８００℃では、ガスタービン静翼に用いられる精密鋳造材と同等以上のγ′相が析出する。 CON222 is a component that is difficult to hot work because the solid solution temperature of the γ ′ phase is 1000 ° C. or higher, and is used as a precision casting material for stationary blades of gas turbines, and creeps at 800 ° C. for 100,000 hours. The breaking strength is about 100 MPa. Although the γ ′ phase solid solution temperature of the inventive material is equivalent to that of a conventional forged alloy, a γ ′ phase equivalent to or higher than that of the precision cast material used for the gas turbine stationary blade is precipitated at 700 to 800 ° C.
次に本発明材について、高温強度評価を行った結果を示す。評価は、発明材ＡおよびＢについて実施した。比較材としては、ＣＯＮ１４１，ＣＯＮ２６３，ＣＯＮ７５０およびＣＯＮ９３９を用いた。ＣＯＮ７５０は、従来の大型鍛造材としては最強強度レベルの合金に相当し、航空機エンジンのタービンディスクに用いられている。 Next, the results of high-temperature strength evaluation of the material of the present invention will be shown. The evaluation was performed on the inventive materials A and B. As comparative materials, CON141, CON263, CON750 and CON939 were used. CON750 corresponds to an alloy having the strongest strength level as a conventional large forged material, and is used for a turbine disk of an aircraft engine.
ＣＯＮ２２２は、前記の通り鍛造が困難であり、精密鋳造材としてガスタービンの静翼などに用いられている。これらの試料は、高周波真空溶解にて２０kgずつ溶解した後、熱間鍛造を行い４０mmφの丸棒とした。鍛造温度は１０５０〜１２００℃とした。 As described above, the CON 222 is difficult to forge and is used as a precision casting material for a stationary blade of a gas turbine. These samples were melted 20 kg at a time by high-frequency vacuum melting, and then hot forged into 40 mmφ round bars. The forging temperature was 1050 to 1200 ° C.
ＣＯＮ２２２以外の試料は、問題なく鍛造できたが、ＣＯＮ２２２では、表面割れが発生し傷をグラインダで除去し鍛造を続行した。 Samples other than CON222 could be forged without problems. However, in CON222, surface cracking occurred and scratches were removed with a grinder, and forging was continued.
次に、熱間スエージング装置を用いて、４０mmφの丸棒を１５mmφまで加工した。ＣＯＮ２２２は３０mmφ程度で大きな割れが発生し続行不可能となった。 Next, a 40 mmφ round bar was processed to 15 mmφ using a hot swaging device. CON222 had a large crack of about 30mmφ and could not be continued.
その他の試料は、問題なく１５mmφの丸棒に熱間加工できた。これらの試料は、γ′相の固溶温度以上で溶体化処理を行った後、γ′相の固溶温度以下で時効処理を行い５０〜１００ｎｍのγ′相を析出させ試料とした。溶体化時効処理を行った１５mmφの丸棒から平行部直径６mm，平行部長さ３０mmのクリープ試験片を採取し、８００〜８５０℃においてクリープ試験を行った。 Other samples could be hot-worked into 15 mmφ round bars without problems. These samples were subjected to solution treatment at a temperature equal to or higher than the solid solution temperature of the γ ′ phase, and then subjected to an aging treatment at a temperature equal to or lower than the solid solution temperature of the γ ′ phase to precipitate a 50 to 100 nm γ ′ phase. A creep test piece having a parallel part diameter of 6 mm and a parallel part length of 30 mm was taken from a 15 mmφ round bar subjected to solution aging treatment, and a creep test was conducted at 800 to 850 ° C.
図３にクリープ試験の結果を示す。なお、ＣＯＮ２２２は熱間加工が困難であったため、真空溶解で作製したインゴットを再溶解し１５mmφの丸棒形状に精密鋳造を行った。 FIG. 3 shows the result of the creep test. Since it was difficult to perform hot working on CON222, an ingot produced by vacuum melting was remelted and precision cast into a 15 mmφ round bar shape.
本発明材は、ＣＯＮ７５０の３倍以上のクリープ破断寿命を示し、ＣＯＮ７５０のクリープ耐用温度は７５０℃であるが、ラルソンミラー法（ＬＭＰ＝〔絶対温度〕×（log（〔クリープ破断時間〕）＋２０）／１０００）により推定される発明材Ａ，Ｂ，Ｃのクリープ耐用温度（１０万時間クリープ破断強度が１００ＭＰａとなる推定温度）はそれぞれ７７５℃，７８０℃，８００℃であった。 The material of the present invention exhibits a creep rupture life three times or more that of CON750, and CON750 has a creep service temperature of 750 ° C., but the Larson Miller method (LMP = [absolute temperature] × (log ([creep rupture time])) + 20 ) / 1000), the creep durability temperatures (estimated temperatures at which the 100,000 hour creep rupture strength becomes 100 MPa) of the inventive materials A, B, and C were 775 ° C., 780 ° C., and 800 ° C., respectively.
発明材Ｄはさらに高いクリープ強度を示した。以上の結果から、本発明材は従来の鍛造合金と比較して極めて高強度でありながら、従来材と同等の熱間加工性を示す優れた鍛造合金であることが示された。 Inventive material D exhibited even higher creep strength. From the above results, it was shown that the material of the present invention is an excellent forged alloy exhibiting hot workability equivalent to that of the conventional material while having extremely high strength as compared with the conventional forged alloy.
このように、本発明により、蒸気タービン，ガスタービンのさらなる高効率化が可能となり、ＣＯ2排出量を大幅に削減できる。 As described above, according to the present invention, the steam turbine and the gas turbine can be further improved in efficiency, and the CO 2 emission amount can be greatly reduced.
本発明材を用いて作製した鍛造部品の例を以下に示めす。 Examples of forged parts produced using the material of the present invention are shown below.
図４（ａ）は本発明材を蒸気タービンプラントのボイラチューブに適用した場合の例である。蒸気タービンプラントの主蒸気温度は６００〜６２０℃が最高であり、さらなる高効率化のために主蒸気温度を７００℃に高める研究開発が進められている。主蒸気温度が７００℃の場合、ボイラの最高温度は７５０℃になる。従来の鍛造材料の耐用温度は７５０℃までが限界であったため、主蒸気温度を７００℃以上に高めるのは困難である。 FIG. 4A shows an example in which the material of the present invention is applied to a boiler tube of a steam turbine plant. The main steam temperature of the steam turbine plant is highest at 600 to 620 ° C., and research and development for increasing the main steam temperature to 700 ° C. is being promoted for further efficiency improvement. When the main steam temperature is 700 ° C., the maximum boiler temperature is 750 ° C. Since the service temperature of conventional forging materials is limited to 750 ° C., it is difficult to increase the main steam temperature to 700 ° C. or higher.
本発明材の耐用温度は７５０℃〜８００℃以上であり、本発明材をボイラチューブに用いれば、主蒸気温度を７３０℃以上に高めることが可能となる。主蒸気はタービンに流れ、仕事をした後、３００℃近くまで温度が下がり、再びボイラに戻り再加熱され再熱蒸気となる。再熱温度は、主蒸気温度よりも高いのが一般的であるが、圧力は大きく低下するため、本発明材を用いれば再熱温度はボイラ内で８００℃以上、タービンに供給する再熱蒸気の温度は７５０℃以上に高めることができる。 The service temperature of the material of the present invention is 750 ° C. to 800 ° C. or higher. If the material of the present invention is used for a boiler tube, the main steam temperature can be increased to 730 ° C. or higher. The main steam flows to the turbine, and after working, the temperature drops to near 300 ° C., returns to the boiler again, is reheated, and becomes reheated steam. The reheat temperature is generally higher than the main steam temperature. However, since the pressure is greatly reduced, the reheat temperature is 800 ° C. or higher in the boiler when the material of the present invention is used. The temperature of can be raised to 750 ° C. or higher.
図４（ｂ）は、本発明材をタービンロータに適用した場合の例を示す。超合金は製造設備の制約から１０ton程度の鍛造品の製造が限界であり、ロータが１０tonを超える場合には、溶接構造のロータとなり、蒸気入り口側の高温部を超合金、低温部はフェライト鋼とし、本発明材は最も温度の高い部位に用いる。従来の鍛造材の耐用温度の限界は７５０℃であるため、蒸気温度が７５０℃以上になるとロータ材の耐用温度を超えるため、再熱蒸気が流入する再熱タービンでは、主蒸気側の低温高圧蒸気を用いて冷却を行う必要がある。 FIG.4 (b) shows the example at the time of applying this invention material to a turbine rotor. Superalloys are limited to the production of forgings of about 10 tons due to restrictions on manufacturing equipment. If the rotor exceeds 10 tons, it becomes a rotor with a welded structure, the superalloy is the high temperature part on the steam inlet side, and the low temperature part is ferritic steel. The material of the present invention is used for a part having the highest temperature. Since the limit of the service temperature of the conventional forging material is 750 ° C., when the steam temperature exceeds 750 ° C., the service temperature of the rotor material is exceeded. Therefore, in the reheat turbine into which reheat steam flows, the low temperature and high pressure on the main steam side It is necessary to cool with steam.
冷却を行う場合、構造が複雑になるとともに熱効率が低下するという問題があるが、本発明材をロータ高温部に用いた場合、耐用温度が７５０℃以上であるため冷却が不要となる。 In the case of cooling, there is a problem that the structure becomes complicated and the thermal efficiency is lowered. However, when the material of the present invention is used in the high temperature part of the rotor, the service temperature is 750 ° C. or higher, so that cooling is unnecessary.
図４（ｃ）は本発明材をタービンケーシングのボルトに用いた場合の例である。タービンケーシングは耐圧部品であり、高温高圧に耐える必要があり鋳造材で上下別々に製作されボルト締結で一体化するのが一般的である。温度の上昇に対してはケーシングの肉厚を増やすことで対応可能である。しかし、従来の鍛造材を用いた場合、クリープ変形によりボルトの緩みが大きくなるという問題がある。本発明材をボルトに用いた場合、ボルトの対応温度が大きく向上し、ボルトの緩みが発生しなくなる。 FIG.4 (c) is an example at the time of using this invention material for the bolt of a turbine casing. The turbine casing is a pressure-resistant component and needs to withstand high temperature and pressure, and is generally manufactured separately from upper and lower parts by casting and integrated by bolt fastening. The increase in temperature can be dealt with by increasing the thickness of the casing. However, when a conventional forging material is used, there is a problem that the bolt loosens due to creep deformation. When the material of the present invention is used for a bolt, the corresponding temperature of the bolt is greatly improved, and the bolt is not loosened.
本発明は、ガスタービン，蒸気タービン等の高温部品および高温部品に利用できるものである。 The present invention can be used for high-temperature parts and high-temperature parts such as gas turbines and steam turbines.
Claims (8)
前記高温部が、Ｎｉ基鍛造合金で構成されており、
前記Ｎｉ基鍛造合金が、
Ｃ：０．００１〜０．１wt.％、
Ｃｒ：１５〜２３wt.％、
Ａｌ：３．５〜５．０wt.％、
Ｃｏ：１５〜２３wt.％、
Ｍｏ：５wt.％以下、
ＭｏとＷの和：５〜１２wt.％、
Ｔｉ，Ｔａ及びＮｂの総和：０.５wt.％以下を含み
残部がＮｉと不可避不純物であることを特徴とする蒸気タービンロータ。 In the steam turbine rotor in which the high temperature part on the steam inlet side and the low temperature part are connected via a weld,
The high temperature part is made of a Ni-based forged alloy,
The Ni-based forged alloy is
C: 0.001 to 0.1 wt.%,
Cr: 15-23 wt.%,
Al: 3.5 to 5.0 wt.%,
Co: 15-23 wt.%,
Mo : 5 wt.% Or less,
Sum of Mo and W : 5-12 wt.%,
A total of Ti, Ta, and Nb : A steam turbine rotor including 0.5 wt.% Or less , the balance being Ni and inevitable impurities.
前記Ｎｉ基鍛造合金が、Ｃ：０．００１〜０．０４wt.％を含むことを特徴とする蒸気タービンロータ。 In claim 1,
The Ni-based forged alloy contains C: 0.001 to 0.04 wt.% .
前記Ｎｉ基鍛造合金が、Ａｌ：４〜５wt.％を含むことを特徴とする蒸気タービンロータ。The steam turbine rotor, wherein the Ni-based forged alloy contains Al: 4 to 5 wt.%.
Ｃｒ：１５〜２３wt.％、Cr: 15-23 wt.%,
Ａｌ：３．５〜５．０wt.％、Al: 3.5 to 5.0 wt.%,
Ｃｏ：１５〜２３wt.％、Co: 15-23 wt.%,
Ｍｏ：５wt.％以下、Mo: 5 wt.% Or less,
ＭｏとＷの和：５〜１２wt.％、Sum of Mo and W: 5-12 wt.%,
Ｔｉ，Ｔａ及びＮｂの総和：０.５wt.％以下を含み、Total of Ti, Ta and Nb: including 0.5 wt.% Or less,
残部がＮｉと不可避不純物であることを特徴とするＮｉ基鍛造合金。A Ni-based forged alloy characterized in that the balance is Ni and inevitable impurities.
Ｃ：０．００１〜０．０４wt.％を含むことを特徴とするＮｉ基鍛造合金。C: Ni-based forged alloy containing 0.001 to 0.04 wt.%.
Ａｌ：４〜５wt.％を含むことを特徴とするＮｉ基鍛造合金。Al: Ni-based forged alloy containing 4 to 5 wt.%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012095206A JP5373147B2 (en) | 2012-04-19 | 2012-04-19 | Steam turbine rotor, Ni-based forged alloy, boiler tube for steam turbine plant |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012095206A JP5373147B2 (en) | 2012-04-19 | 2012-04-19 | Steam turbine rotor, Ni-based forged alloy, boiler tube for steam turbine plant |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2007271925A Division JP4982324B2 (en) | 2007-10-19 | 2007-10-19 | Ni-based forged alloy, forged parts for steam turbine plant, boiler tube for steam turbine plant, bolt for steam turbine plant, and steam turbine rotor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2012177370A JP2012177370A (en) | 2012-09-13 |
| JP5373147B2 true JP5373147B2 (en) | 2013-12-18 |
Family
ID=46979347
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2012095206A Expired - Fee Related JP5373147B2 (en) | 2012-04-19 | 2012-04-19 | Steam turbine rotor, Ni-based forged alloy, boiler tube for steam turbine plant |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5373147B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6942871B2 (en) * | 2017-11-17 | 2021-09-29 | 三菱パワー株式会社 | Manufacturing method of Ni-based forged alloy material |
| KR102193336B1 (en) | 2017-11-17 | 2020-12-22 | 미츠비시 파워 가부시키가이샤 | Ni-based forged alloy material and turbine high-temperature member using the same |
| EP3719163A1 (en) * | 2019-04-02 | 2020-10-07 | Siemens Aktiengesellschaft | Fastener for a valve or turbine housing |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10331659A (en) * | 1997-06-02 | 1998-12-15 | Hitachi Ltd | Power generating gas turbine and combined power generating system |
| JP2004036469A (en) * | 2002-07-03 | 2004-02-05 | Hitachi Ltd | Steam turbine rotor |
| JP2004256840A (en) * | 2003-02-24 | 2004-09-16 | Japan Steel Works Ltd:The | COMPOSITE REINFORCED TYPE Ni BASED SUPERALLOY, AND PRODUCTION METHOD THEREFOR |
| JP4123064B2 (en) * | 2003-06-13 | 2008-07-23 | 株式会社日立製作所 | Steam turbine rotor and steam turbine plant |
| JP4387331B2 (en) * | 2005-06-30 | 2009-12-16 | 株式会社日本製鋼所 | Ni-Fe base alloy and method for producing Ni-Fe base alloy material |
-
2012
- 2012-04-19 JP JP2012095206A patent/JP5373147B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2012177370A (en) | 2012-09-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4982324B2 (en) | Ni-based forged alloy, forged parts for steam turbine plant, boiler tube for steam turbine plant, bolt for steam turbine plant, and steam turbine rotor | |
| JP5165008B2 (en) | Ni-based forged alloy and components for steam turbine plant using it | |
| JP5127749B2 (en) | Ni-base alloy for turbine rotor of steam turbine and turbine rotor of steam turbine using the same | |
| JP6057363B1 (en) | Method for producing Ni-base superalloy | |
| JP4261562B2 (en) | Ni-Fe based forged superalloy excellent in high temperature strength and high temperature ductility, its manufacturing method, and steam turbine rotor | |
| JP5478601B2 (en) | Ni-based forged alloy and gas turbine using the same | |
| JP5216839B2 (en) | Ni-base heat-resistant alloy, gas turbine member, and turbine with excellent segregation characteristics | |
| JP6223743B2 (en) | Method for producing Ni-based alloy | |
| JPWO2018151222A1 (en) | Ni-base heat-resistant alloy and method for producing the same | |
| JP5537587B2 (en) | Ni-base alloy welding material and welding wire, welding rod and welding powder using the same | |
| JP4987921B2 (en) | Ni-based alloy and cast component for steam turbine using the same, steam turbine rotor, boiler tube for steam turbine plant, bolt for steam turbine plant, and nut for steam turbine plant | |
| JP2012092378A (en) | FORGING Ni-BASED ALLOY OF STEAM TURBINE, AND FORGED COMPONENT THEREOF | |
| JP5373147B2 (en) | Steam turbine rotor, Ni-based forged alloy, boiler tube for steam turbine plant | |
| JP5932622B2 (en) | Austenitic heat resistant steel and turbine parts | |
| JP5356572B2 (en) | Turbine rotor | |
| JP2009221545A (en) | Ni-BASED ALLOY FOR TURBINE ROTOR OF STEAM TURBINE, AND TURBINE ROTOR OF STEAM TURBINE | |
| WO2016111249A1 (en) | Austenite-based heat-resistant steel, and turbine component | |
| JP2015086432A (en) | Austenitic heat resistant steel and turbine component | |
| JP6173822B2 (en) | Austenitic heat resistant steel and turbine parts | |
| JP6173956B2 (en) | Austenitic heat resistant steel and turbine parts | |
| JP5981251B2 (en) | Ni-based alloy and forged parts for forging | |
| JP2010235985A (en) | Nickel-based alloy for forged parts in steam-turbine excellent in high-temperature strength characteristics, forgeability and weldability, and member for steam-turbine | |
| JP2017155264A (en) | Austenitic heat resistant steel and turbine component | |
| WO2016142963A1 (en) | Austenitic heat-resistant steel and turbine component | |
| JP2013136843A (en) | Ni-BASED HEAT RESISTANT ALLOY HAVING EXCELLENT SEGREGATION PROPERTY, GAS TURBINE MEMBER AND GAS TURBINE |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20130528 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20130729 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20130820 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20130918 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 5373147 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |