JPWO2004053177A1 - Ni-based single crystal superalloy - Google Patents

Abstract

Ingredients by weight: Al: 5.0% to 7.0% by weight, Ta: 4.0% to 10.0% by weight, Mo: 1.1% to 4.5% by weight W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt%, Cr: 2.0 wt% % To 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14.0% by weight, with the balance being Ni and inevitable impurities By using a Ni-based single crystal superalloy having a Ni-based single crystal superalloy capable of preventing the precipitation of the TCP phase at a high temperature and improving the strength.

Description

  The present invention relates to a Ni-based single crystal superalloy, and more particularly to an improvement in a Ni-based single crystal superalloy for the purpose of improving creep characteristics.

上記Ｎｉ基単結晶超合金では、所定の温度で溶体化処理を行った後、時効処理を行ってＮｉ基単結晶超合金を得ている。この合金は、いわゆる析出硬化型合金と呼ばれており、母相であるγ相中に、析出相であるγ’相が析出した形態を有している。
表１に挙げた合金のうち、ＣＭＳＸ−２（キャノン・マスケゴン社製、米国特許第４，５８２，５４８号参照）は第１世代合金、ＣＭＳＸ−４（キャノン・マスケゴン社製、米国特許第４，６４３，７８２号参照）は第２世代合金、Ｒｅｎｅ’Ｎ６（ゼネラル・エレクトリック社製、米国特許第５，４５５，１２０号参照）、ＣＭＳＸ−１０Ｋ（キャノン・マスケゴン社製、米国特許第５，３６６，６９５号参照）は第３世代合金、３Ｂ（ゼネラル・エレクトリック社製、米国特許第５，１５１，２４９号参照）は第４世代合金と呼ばれている。
上記の第１世代合金であるＣＭＳＸ−２や、第２世代合金であるＣＭＳＸ−４は、低温下でのクリープ強度は遜色ないものの、高温の溶体化処理後においても共晶γ’相が多量に残存し、第３世代合金と比較して高温下でのクリープ強度が劣る。
また、上記の第３世代であるＲｅｎｅ’Ｎ６やＣＭＳＸ−１０Ｋは、第２世代合金よりも高温下でのクリープ強度の向上を目的とした合金である。しかしながら、Ｒｅの組成比（５重量％以上）が母相（γ相）へのＲｅ固溶量を越えるため、余剰のＲｅが他の元素と化合して高温下でいわゆるＴＣＰ相（Ｔｏｐｏｌｏｇｉｃａｌｌｙ Ｃｌｏｓｅ Ｐａｃｋｅｄ相）を析出させ、高温下における長時間の使用によりこのＴＣＰ相の量が増加してクリープ強度が低下するという問題があった。
また、Ｎｉ基単結晶超合金のクリープ強度を向上させるには、析出相（γ’相）の格子定数を母相（γ相）の格子定数よりわずかに小さくすることが有効であるが、各相の格子定数は合金の構成元素の組成比により大きく変動するため、格子定数の微妙な調整が困難であるためにクリープ強度の向上を図ることが難しいという問題があった。
本発明は上記事情に鑑みてなされたものであって、高温下でのＴＣＰ相の析出を防止して強度の向上を図ることが可能なＮｉ基単結晶超合金の提供を目的とする。Examples of typical compositions of Ni-based single crystal superalloys that have been developed as materials for moving and stationary blades at high temperatures such as aircraft and gas turbines include those shown in Table 1.

In the Ni-based single crystal superalloy, a solution treatment is performed at a predetermined temperature, and then an aging treatment is performed to obtain a Ni-based single crystal superalloy. This alloy is called a so-called precipitation hardening type alloy, and has a form in which a γ ′ phase as a precipitation phase is precipitated in a γ phase as a parent phase.
Among the alloys listed in Table 1, CMSX-2 (manufactured by Canon Maskegon, see US Pat. No. 4,582,548) is a first generation alloy, CMSX-4 (manufactured by Canon Maskegon, US Pat. No. 4). , 643,782) is a second generation alloy, Rene'N6 (manufactured by General Electric, see US Pat. No. 5,455,120), CMSX-10K (manufactured by Canon Muskegon, US Pat. No. 366,695) is a third generation alloy, and 3B (general electric, see US Pat. No. 5,151,249) is called a fourth generation alloy.
CMSX-2, the first generation alloy, and CMSX-4, the second generation alloy, have a high eutectic γ 'phase even after high temperature solution treatment, although the creep strength at low temperatures is comparable. The creep strength at high temperatures is inferior to that of the third generation alloy.
Further, the above-mentioned third generation Rene'N6 and CMSX-10K are alloys aiming at improving the creep strength at a higher temperature than the second generation alloys. However, since the composition ratio of Re (5% by weight or more) exceeds the amount of Re solid solution in the parent phase (γ phase), excess Re combines with other elements to form a so-called TCP phase (Topologically Closed Packed). Phase) and the amount of the TCP phase increases due to long-term use at high temperatures, resulting in a decrease in creep strength.
In order to improve the creep strength of the Ni-based single crystal superalloy, it is effective to make the lattice constant of the precipitated phase (γ ′ phase) slightly smaller than the lattice constant of the parent phase (γ phase). Since the lattice constant of the phase largely fluctuates depending on the composition ratio of the constituent elements of the alloy, there is a problem that it is difficult to improve the creep strength because fine adjustment of the lattice constant is difficult.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a Ni-based single crystal superalloy capable of preventing the precipitation of a TCP phase at a high temperature and improving the strength.

In order to achieve the above object, the present invention employs the following configuration.
In the Ni-based single crystal superalloy of the present invention, the components are in a weight ratio of Al: 5.0% by weight to 7.0% by weight, Ta: 4.0% by weight to 10.0% by weight, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 14.0 wt% or less The remainder has a composition comprising Ni and inevitable impurities.
In addition, the Ni-based single crystal superalloy of the present invention has components in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 6.0 wt% or less, Mo : 1.1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% or more 0.50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 14.0 wt% or less It has a composition comprising Ni and inevitable impurities.
In addition, the Ni-based single crystal superalloy of the present invention has components in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 6.0 wt% or less, Mo : 2.9 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% or more 0.50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 14.0 wt% or less It has a composition comprising Ni and inevitable impurities.
According to the Ni-based single crystal superalloy described above, the addition of Ru suppresses the precipitation of the TCP phase that causes a decrease in strength when used at high temperatures. In addition, by setting the composition ratio of other constituent elements in an optimum range, it is possible to optimize the lattice constant of the parent phase (γ phase) and the lattice constant of the precipitated phase (γ ′ phase). . As a result, the strength at high temperature can be improved. Further, since the Ru composition ratio is 4.1 wt% or more and 14.0 wt% or less, the precipitation of the TCP phase that causes a decrease in creep strength at the time of high temperature use is suppressed.
Further, in the Ni-based single crystal superalloy described above, the components are in a weight ratio of Al: 5.9 wt%, Ta: 5.9 wt%, Mo: 3.9 wt%, W: 5.9 wt%. %, Re: 4.9% by weight, Hf: 0.10% by weight, Cr: 2.9% by weight, Co: 5.9% by weight, Ru: 5.0% by weight, the balance being inevitable with Ni It is desirable to have a composition consisting of mechanical impurities.
According to the Ni-based single crystal superalloy having the above composition, the creep durability temperature at 137 MPa and 1000 hours can be set to 1344 K (1071 ° C.).
Further, in the Ni-based single crystal superalloy described above, the components are in a weight ratio of Co: 5.8 wt%, Cr: 2.9 wt%, Mo: 3.1 wt%, W: 5.8 wt%. %, Al: 5.8 wt%, Ta: 5.6 wt%, Ru: 5.0 wt%, Re: 4.9 wt%, Hf: 0.10 wt%, and the balance is inevitable with Ni It is desirable to have a composition consisting of mechanical impurities.
According to the Ni-based single crystal superalloy having the above composition, the creep durability temperature at 137 MPa and 1000 hours can be set to 1366 K (1093 ° C.).
In the Ni-based single crystal superalloy described above, the components are in a weight ratio of Co: 5.8 wt%, Cr: 2.9 wt%, Mo: 3.9 wt%, W: 5.8 wt%. %, Al: 5.8 wt%, Ta: 5.8 wt% (5.82 wt%) or 5,6 wt%, Ru: 6.0 wt%, Re: 4.9 wt%, Hf: 0 It is desirable to have a composition containing 10% by weight with the balance being Ni and inevitable impurities.
According to the Ni-based single crystal superalloy having the composition described above, the creep durability temperature at 137 MPa and 1000 hours can be set to 1375 K (1102 ° C.) or 1379 K (1106 ° C.).
Further, the Ni-based single crystal superalloy described above may further contain 0 wt% or more and 2.0 wt% or less of Ti by weight.
Further, the Ni-based single crystal superalloy described above may further contain 0% by weight to 4.0% by weight of Nb by weight ratio.
In addition, the Ni-based single crystal superalloy described above may include at least one of B, C, Si, Y, La, Ce, V, and Zr.
In this case, the individual components are, by weight ratio, B: 0.05% by weight or less, C: 0.15% by weight or less, Si: 0.1% by weight or less, Y: 0.1% by weight or less, La: It is preferable that they are 0.1 weight% or less, Ce: 0.1 weight% or less, V: 1 weight% or less, Zr: 0.1 weight% or less.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 10.0 wt%. Wt% or less, Mo: 1.1 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0 wt% to 0.50 wt%, Cr: 2.0 wt% to 5.0 wt%, Co: 0 wt% to 9.9 wt%, Ru: 10.0 wt% to 14. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2.0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less Having a composition that.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.8 wt% to 7.0 wt%, Ta: 4.0 wt% to 5.6 Wt% or less, Mo: 3.3 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0% by weight to 0.50% by weight, Cr: 2.9% by weight to 4.3% by weight, Co: 0% by weight to 9.9% by weight, Ru: 4.1% by weight to 14. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2.0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less Having formed.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 10.0 wt%. Wt% or less, Mo: 1.1 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0% by weight to 0.50% by weight, Cr: 2.9% by weight to 5.0% by weight, Co: 0% by weight to 9.9% by weight, Ru: 6.5% by weight to 14. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2.0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less Having the composition.
Further, in the Ni-based single crystal superalloy described above, it is more desirable that the components are in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 6.0 wt%. Wt% or less, Mo: 3.3 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0% to 0.50% by weight, Cr: 2.0% to 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14%. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2.0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less Having formed.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.0% by weight or more and 7.0% by weight or less, Ta: 4.0% by weight or more and 5.6%. Wt% or less, Mo: 3.3 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0% to 0.50% by weight, Cr: 2.0% to 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14%. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2.0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less Having formed.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 10.0 wt%. Wt% or less, Mo: 3.1 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0% to 0.50% by weight, Cr: 2.0% to 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14%. 0 wt% or less, Nb: 4.0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.8 wt% to 7.0 wt%, Ta: 4.0 wt% to 10.0 wt%. Wt% or less, Mo: 3.1 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0% to 0.50% by weight, Cr: 2.0% to 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14%. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less Having.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 10.0 wt%. Wt% or less, Mo: 3.1 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0% by weight to 0.50% by weight, Cr: 2.9% by weight to 4.3% by weight, Co: 0% by weight to 9.9% by weight, Ru: 4.1% by weight to 14. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less Having.
Further, the Ni-based single crystal superalloy of the present invention more preferably has components in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta + Nb + Ti: 4.0 wt% or more and 10.0 wt% %: Mo: 3.3 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 to 0.50% by weight, Cr: 2.0 to 5.0% by weight, Co: 0 to 9.9% by weight, Ru: 4.1 to 14.0% % By weight, B: 0.05% by weight or less, C: 0.15% by weight or less, Si: 0.1% by weight or less, Y: 0.1% by weight or less, La: 0.1% by weight or less, Ce : 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less.
Furthermore, the Ni-based single crystal superalloy of the present invention is the Ni-based single crystal superalloy described above, where a2 ≦ 0 when the lattice constant of the parent phase is a1 and the lattice constant of the precipitated phase is a2. 999a1.
According to the Ni-based single crystal superalloy described above, when the lattice constant of the parent phase is a1 and the lattice constant of the precipitated phase is a2, the relationship between a1 and a2 is a2 ≦ 0.999a1, and the lattice of the precipitated phase Since the constant a2 is minus 0.1% or less of the lattice constant a1 of the parent phase, the precipitated phase that precipitates in the parent phase precipitates so as to continuously extend in the direction perpendicular to the load direction, and dislocation occurs under stress. Defects are less likely to move through the alloy structure. As a result, it is possible to increase the strength at high temperatures as compared with conventional Ni-based single crystal superalloys.
In this case, more preferably, the lattice constant a2 of the crystal of the precipitated phase is set to 0.9965 or less of the lattice constant a1 of the crystal of the parent phase.
Furthermore, the Ni-based single crystal superalloy of the present invention is characterized in that the transition network spacing in the alloy is 40 nm or less.

FIG. 1 is a diagram showing the relationship between lattice misfit and creep life.
FIG. 2 is a diagram showing the relationship between transition network spacing and creep life.
FIG. 3 is a transmission electron micrograph of a Ni-based single crystal superalloy illustrating the transition network of the Ni-based single crystal superalloy of the present invention and the distance between the transition networks.

Hereinafter, embodiments of the present invention will be described in detail.
The Ni-based single crystal superalloy of the present invention is an alloy containing components such as Al, Ta, Mo, W, Re, Hf, Cr, Co, and Ru, and Ni (remainder), and further containing inevitable impurities. is there.
In the Ni-based single crystal superalloy described above, for example, the composition ratio is Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 10.0 wt% or less, Mo: 1.1 Wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt % Or less, Cr: 2.0% by weight or more and 5.0% by weight or less, Co: 0% by weight or more and 9.9% by weight or less, Ru: 4.1% by weight or more and 14.0% by weight or less, and the balance An alloy composed of Ni and inevitable impurities.
The Ni-based single crystal superalloy has a composition ratio of, for example, Al: 5.0% by weight or more and 7.0% by weight or less, Ta: 4.0% by weight or more and 6.0% by weight or less, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 14.0 wt% or less The balance is an alloy composed of Ni and inevitable impurities.
The Ni-based single crystal superalloy has a composition ratio of, for example, Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 6.0 wt% or less, Mo: 2 0.9 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 14.0 wt% or less The balance is an alloy composed of Ni and inevitable impurities.
Each of the alloys has a γ phase (parent phase) that is an austenite phase and a γ ′ phase (precipitation phase) that is an intermediate ordered phase dispersed and precipitated in the parent phase. The γ ′ phase is mainly composed of an intermetallic compound represented by Ni 3 Al, and this γ ′ phase improves the high temperature strength of the Ni-based single crystal superalloy.
Cr is an element excellent in oxidation resistance, and improves the high temperature corrosion resistance of the Ni-based single crystal superalloy.
The composition ratio of Cr is preferably in the range of Cr: 2.0 wt% or more and 5.0 wt% or less, more preferably 2.9 wt% or more and 5.0 wt% or less, and more preferably 2.9 wt% or more and 4 wt% or less. The range of .3% by weight or less is more preferable, and the range of 2.9% by weight is most preferable.
If the Cr composition ratio is less than 2.0% by weight, the desired high-temperature corrosion resistance cannot be ensured, which is not preferable. If the Cr composition ratio exceeds 5.0% by weight, precipitation of the γ ′ phase is suppressed. Since harmful phases such as σ phase and μ phase are generated and high temperature strength is lowered, it is not preferable.
In the presence of W and Ta, Mo dissolves in the γ phase, which is the parent phase, to increase the high temperature strength and contribute to the high temperature strength by precipitation hardening. Further, Mo greatly contributes to lattice misfit and dislocation network spacing (described later), which are characteristics of this alloy.
The composition ratio of Mo is preferably in the range of 1.1 wt% to 4.5 wt%, more preferably in the range of 2.9 wt% to 4.5 wt%, and more preferably 3.1 wt% to 4.5 wt%. A range of not more than wt%, or a range of not less than 3.3 wt% and not more than 4.5 wt% is more preferred, and most preferred is 3.1 wt% or 3.9 wt%.
If the Mo composition ratio is less than 1.1% by weight, the desired high-temperature strength cannot be secured. On the other hand, even if the Mo composition ratio exceeds 4.5% by weight, the high-temperature strength decreases, Is not preferable because the high-temperature corrosion resistance also decreases.
W improves the high-temperature strength by the action of solid solution strengthening and precipitation hardening in the presence of Mo and Ta as described above.
The W composition ratio is preferably in the range of 4.0 wt% to 10.0 wt%, and most preferably 5.9 wt% or 5.8 wt%.
If the W composition ratio is less than 4.0% by weight, the desired high-temperature strength cannot be ensured. This is not preferable, and if the W composition ratio exceeds 10.0% by weight, the high-temperature corrosion resistance decreases.
Ta improves the high-temperature strength by the action of solid solution strengthening and precipitation hardening in the presence of Mo and W as described above, and partly precipitates and hardens against the γ 'phase to improve the high-temperature strength. .
The composition ratio of Ta is preferably in the range of 4.0 wt% to 10.0 wt%, more preferably 4.0 wt% to 6.0 wt%, and more preferably 4.0 wt% to 5.6 wt%. A range of not more than wt% is more preferred, and most preferred is 5.6 wt% or 5.82 wt%.
If the Ta composition ratio is less than 4.0% by weight, the desired high-temperature strength cannot be ensured, which is not preferable. If the Ta composition ratio exceeds 10.0% by weight, a σ phase or μ phase is generated. This is not preferable because the high temperature strength decreases.
Al is combined with Ni to form an intermetallic compound represented by Ni ₃ Al) constituting a γ ′ phase that is finely and uniformly dispersed and precipitated in the matrix at a volume fraction of 60 to 70%. , Improve high temperature strength.
The composition ratio of Al is preferably in the range of 5.0% by weight to 7.0% by weight, more preferably in the range of 5.8% by weight to 7.0% by weight, and more preferably 5.9% by weight or 5.8%. Most preferred is wt%.
If the Al composition ratio is less than 5.0% by weight, the amount of precipitation of the γ ′ phase becomes insufficient, and the desired high-temperature strength cannot be secured, which is not preferable. If the Al composition ratio exceeds 7.0% by weight, A large amount of coarse γ phase called a eutectic γ ′ phase is formed, so that solution treatment is impossible and high temperature strength cannot be secured.
Hf is a grain boundary segregation element and is unevenly distributed in the grain boundaries of the γ phase and the γ ′ phase to strengthen the grain boundaries, thereby improving the high temperature strength.
The composition ratio of Hf is preferably in the range of 0.01 wt% to 0.50 wt%, and most preferably 0.10 wt%.
If the Hf composition ratio is less than 0.01% by weight, the amount of precipitation of the γ ′ phase becomes insufficient, and the desired high-temperature strength cannot be ensured. However, if necessary, the composition ratio of Hf may be 0 wt% or more and less than 0.01 wt%. On the other hand, if the Hf composition ratio exceeds 0.50% by weight, it is not preferable because local melting may occur and the high-temperature strength may be reduced.
Co increases the solid solution limit of Al, Ta, and other parent phases at high temperatures, disperses and precipitates fine γ ′ phases by heat treatment, and improves high-temperature strength.
The composition ratio of Co is preferably in the range of 0.1 wt% to 9.9 wt%, and most preferably 5.8 wt%.
If the Co composition ratio is less than 0.1% by weight, the amount of precipitation of the γ ′ phase becomes insufficient, and the desired high-temperature strength cannot be ensured. However, if necessary, the Co composition ratio may be 0 wt% or more and less than 0.1 wt%. Further, if the Co composition ratio exceeds 9.9% by weight, the balance with other elements such as Al, Ta, Mo, W, Hf, and Cr will be lost, and a harmful phase will precipitate and the high temperature strength will decrease. It is not preferable.
Re dissolves in the γ phase, which is the parent phase, and improves high-temperature strength by solid solution strengthening. It also has the effect of improving corrosion resistance. On the other hand, when a large amount of Re is added, a TCP phase, which is a harmful phase, precipitates at a high temperature, and the high-temperature strength may be reduced.
The composition ratio of Re is preferably in the range of 3.1 wt% to 8.0 wt%, and most preferably 4.9 wt%.
If the Re composition ratio is less than 3.1% by weight, the solid solution strengthening of the γ phase is insufficient and the desired high-temperature strength cannot be ensured, and the Re composition ratio exceeds 8.0% by weight. In this case, the TCP phase is precipitated at high temperatures, and high high-temperature strength cannot be secured.
Ru suppresses the precipitation of the TCP phase, thereby improving the high temperature strength.
The composition ratio of Ru is in the range of 4.1 wt% to 14.0 wt%, or in the range of 10.0 wt% to 14.0 wt%, or 6.5 wt% to 14.0 wt%. The following range is preferable, and it is most preferable to set it as 5.0 weight% or 6.0 weight% or 7.0 weight%.
When the composition ratio of Ru is less than 1.0% by weight, a TCP phase is precipitated at a high temperature, and a high high-temperature strength cannot be ensured. Furthermore, when the Ru composition ratio is less than 4.1% by weight, the high-temperature strength is lowered as compared with the case where the Ru composition ratio is 4.1% by weight or more. On the other hand, if the Ru composition ratio exceeds 14.0% by weight, the ε phase is precipitated and the high-temperature strength decreases, which is not preferable.
In the present invention, by adjusting the composition ratio of Al, Ta, Mo, W, Hf, Cr, Co, Re, and Ni to an optimum one, the lattice constant of the γ phase and the lattice constant of the γ ′ phase are calculated. While setting the lattice misfit and the transition network spacing (described later) to the optimum ranges to improve the high-temperature strength, the addition of Ru can suppress the precipitation of the TCP phase. In particular, the production cost of the alloy can be reduced by setting the composition ratio of Al, Cr, Ta, and Mo as described above. Furthermore, the specific strength can be improved, and lattice misfit and transition network spacing can be set to optimum values.
Further, in a use environment at a high temperature such as 1273 K (1000 ° C.) to 1373 K (1100 ° C.), the lattice constant of the crystal constituting the γ phase as the parent phase is a1, and the γ ′ phase as the precipitated phase is constituted. When the lattice constant of the crystal is a2, the relationship between a1 and a2 is preferably a2 ≦ 0.999a1. That is, it is preferable that the lattice constant a2 of the crystal of the precipitated phase is not more than minus 0.1% of the lattice constant a1 of the crystal of the parent phase. More preferably, the lattice constant a2 of the crystal of the precipitated phase is 0.9965 or less of the lattice constant a1 of the crystal of the parent phase. In this case, the relationship between a1 and a2 described above is a2 ≦ 0.9965a1. In the following description, the percentage of the crystal lattice constant a2 of the precipitated phase crystal to the lattice constant a1 of the parent phase crystal is referred to as “lattice misfit”.
When both lattice constants have such a relationship, when the precipitated phase is precipitated in the matrix by heat treatment, the precipitated phase precipitates so as to continuously extend in the direction perpendicular to the load direction. Therefore, dislocation defects are less likely to move in the alloy structure, and the creep strength is increased.
In order to make the relationship between the lattice constant a1 and the lattice constant a2 a2 ≦ 0.999a1, it is necessary to appropriately adjust the composition of the constituent elements constituting the Ni-based single crystal superalloy.
FIG. 1 shows the relationship between the lattice misfit and the time until creep rupture of the alloy (creep life).
In FIG. 1, it can be seen that if the lattice misfit is approximately −0.35 or less, the creep life substantially satisfies the required value (value indicated by a dotted line on the vertical axis in the figure). Therefore, in the present invention, a more preferable lattice misfit is set to −0.35 or less. In order to set the lattice misfit to −0.35 or less, it is necessary to adjust the composition ratio of other constituent elements while maintaining the Mo composition ratio high.
According to the Ni-based single crystal superalloy described above, the addition of Ru suppresses the precipitation of the TCP phase that causes a decrease in creep strength during high temperature use. In addition, by setting the composition ratio of other constituent elements in the optimum range, it is possible to optimize the lattice constant of the parent phase (γ phase) and the lattice constant of the precipitated phase (γ 'phase). Become. As a result, the creep strength at high temperatures can be improved.
The Ni-based single crystal superalloy described above may further contain Ti. In this case, the composition ratio of Ti is preferably in the range of 0% by weight to 2.0% by weight. If the composition ratio of Ti exceeds 2.0% by weight, a harmful phase precipitates and the high-temperature strength decreases, which is not preferable.
The Ni-based single crystal superalloy described above may further contain Nb. In this case, the composition ratio of Nb is preferably 0% by weight or more and 4.0% by weight or less. If the composition ratio of Nb exceeds 4.0% by weight, a harmful phase precipitates and the high-temperature strength decreases, which is not preferable.
Alternatively, the high-temperature strength can be improved by setting the composition ratio of Ta, Nb, and Ti to 4.0% by weight or more and 10.0% by weight or less in the total of both (Ta + Nb + Ti).
In addition, the Ni-based single crystal superalloy described above may contain, for example, B, C, Si, Y, La, Ce, V, Zr, etc. in addition to the inevitable impurities. When containing at least one of B, C, Si, Y, La, Ce, V, and Zr, the composition ratio of each component is B: 0.05% by weight or less, C: 0.15% by weight or less Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% % Or less is preferable. If the composition ratio of the individual components exceeds the above range, a harmful phase precipitates and the high-temperature strength decreases, which is not preferable.
In the Ni-based single crystal superalloy described above, the transition network spacing in the alloy is desirably 40 nm or less. The transition network indicates dislocations (displacement of atoms connected in a line) formed in a network in the alloy. The interval between the meshes is defined as the dislocation network interval. FIG. 2 shows the relationship between the transition network interval and the time until creep rupture of the alloy (creep life).
In FIG. 2, it can be seen that the creep life satisfies the required value (the value indicated by the dotted line on the vertical axis in the figure) if the transition network interval is approximately 40 nm or less. Therefore, in the present invention, the preferable transition network interval is set to 40 nm or less. In order to make the transition network interval 40 nm or less, it is necessary to adjust the composition ratio of other constituent elements while keeping the Mo composition ratio high.
FIG. 3 is a transmission electron micrograph of the Ni-based single crystal superalloy illustrating the transition network and intervals of the Ni-based single crystal superalloy of the present invention (Example 3 described later). FIG. 3 shows that the Ni-based single crystal superalloy of the present invention has a transition network interval of 40 nm or less.
In addition, in the conventional Ni-based single crystal superalloy, there are alloys that cause reverse distribution, but the Ni-based single crystal superalloy according to the present invention does not cause reverse distribution.

次に、合金インゴットに対して溶体化処理及び時効処理を行い、合金組織の状態を走査型電子顕微鏡（ＳＥＭ）で観察した。溶体化処理は、１５７３Ｋ（１３００℃）で１時間保持した後、１６０３Ｋ（１３３０℃）まで昇温し、５時間保持した。また、時効処理は、１２７３Ｋ〜１４２３Ｋ（１０００℃〜１１５０℃）で４時間保持する１次時効処理と、１１４３Ｋ（８７０℃）で２０時間保持する２次時効処理を連続して行った。
その結果、各試料ともに、組織中にＴＣＰ相は確認されなかった。
次に、溶体化処理及び時効処理を施した各試料に対して、クリープ試験を行った。クリープ試験は、表３に示す温度及び応力の各条件下で各試料（参考例１〜６、及び実施例１〜１４）がクリープ破断するまでの時間を寿命として測定した。また、格子ミスフィットの値を併せて計測した。これらの結果を表３に示す。さらに、表１に示した従来の合金（比較例１〜比較例５）の格子ミスフィットの値を併せて計測した。これらの結果を表４に示す。

表３から明らかなように、参考例１〜６、及び実施例１〜１４の試料はいずれも、１２７３Ｋ（１０００℃）以上の高温の条件下であっても高い強度を有していることがわかる。特に、Ｒｕの組成比が４．０重量％である参考例５、及びＲｕの組成比がほぼ５．０重量％である実施例１、２、４、９、１０、及び１１、Ｒｕの組成比が６．０重量％である実施例３及び１２、１３、Ｒｕの組成比が７．０重量％である実施例１４は、高い高温強度を有していることがわかる。
また、表３、４から明らかなように、比較例の格子ミスフィットは、−０．３５以上であるのに対して、参考例１〜６、及び実施例１〜１４の試料は、いずれも、格子ミスフィットは−０．３５以下であることがわかる。
さらに、表１に示した従来の合金（比較例１〜比較例５）、及び表２に示した各試料（参考例１〜６、及び実施例１〜１４）に対して、クリープランチャー特性（耐用温度）を比較した。その結果を表５に示す。クリープランチャー特性は、１３７ＭＰａの応力を１０００時間印加した条件で試料が破断するまでの温度を測定した結果、または試料の破断温度をその条件下に換算したものを用いている。

表５から明らかなように、参考例１〜６の試料、及び実施例１〜１４の試料はいずれも、従来の合金（比較例１〜比較例５）に比べて同等以上の高い耐用温度を有していることがわかる。特に、実施例１〜１４はいずれも、高い耐用温度（実施例１：１３４４Ｋ（１０７１℃）、実施例２：１３６８Ｋ（１０９３℃）、実施例３：１３７５Ｋ（１１０２℃）、実施例４：１３７２Ｋ（１０９９℃）、実施例５：１３７９Ｋ（１１０６℃）、実施例６：１３７９Ｋ（１１０６℃）、実施例７：１３７９Ｋ（１１０６℃）、実施例８：１３６３Ｋ（１０９０℃）、実施例９：１３５８Ｋ（１０８５℃）、実施例１０：１３６２Ｋ（１０８９℃）、実施例１１：１３６１Ｋ（１０８８℃）、実施例１２：１３６３Ｋ（１０９０℃）、実施例１３：１３６６Ｋ（１０９３℃）、実施例１４：１３８４Ｋ（１１１１℃））を有していることがわかる。
従って、本実施例１〜１４は、従来のＮｉ基単結晶超合金と比較して高い耐熱温度を有しており、優れた高温強度を有していることがわかる。
なお、Ｎｉ基単結晶超合金では、Ｒｕが必要以上に増えると、ε相が析出して高温強度が低下するため、Ｒｕの含有量は、他の元素とのバランスがくずれない範囲内（例えば、４．１重量％以上１４．０重量％以下）に定められるのが好ましい。Next, an example is shown and the effect of the present invention is explained.
Various melts of Ni-based single crystal superalloys were prepared using a vacuum melting furnace, and a plurality of alloy ingots having different compositions were cast using the molten alloy. Table 2 shows the composition ratio of each alloy ingot (Reference Examples 1 to 6, Examples 1 to 14).

Next, solution treatment and aging treatment were performed on the alloy ingot, and the state of the alloy structure was observed with a scanning electron microscope (SEM). The solution treatment was held at 1573 K (1300 ° C.) for 1 hour, then heated to 1603 K (1330 ° C.) and held for 5 hours. Moreover, the aging treatment performed continuously the primary aging treatment hold | maintained at 1273K-1423K (1000 to 1150 degreeC) for 4 hours, and the secondary aging treatment hold | maintained at 1143K (870 degreeC) for 20 hours.
As a result, no TCP phase was confirmed in the tissues in each sample.
Next, a creep test was performed on each sample subjected to solution treatment and aging treatment. In the creep test, the time until each sample (Reference Examples 1 to 6 and Examples 1 to 14) creep ruptured was measured as the lifetime under the conditions of temperature and stress shown in Table 3. Moreover, the value of lattice misfit was also measured. These results are shown in Table 3. Furthermore, the lattice misfit values of the conventional alloys shown in Table 1 (Comparative Examples 1 to 5) were also measured. These results are shown in Table 4.

As is apparent from Table 3, the samples of Reference Examples 1 to 6 and Examples 1 to 14 have high strength even under high temperature conditions of 1273K (1000 ° C.) or higher. Recognize. In particular, Reference Example 5 in which the Ru composition ratio is 4.0% by weight, and Examples 1, 2, 4, 9, 10, and 11, Ru in which the Ru composition ratio is approximately 5.0% by weight. It can be seen that Examples 3 and 12, 13 in which the ratio is 6.0% by weight, and Example 14 in which the composition ratio of Ru is 7.0% by weight have high high-temperature strength.
Further, as apparent from Tables 3 and 4, the lattice misfit of the comparative example is −0.35 or more, whereas the samples of Reference Examples 1 to 6 and Examples 1 to 14 are all It can be seen that the lattice misfit is -0.35 or less.
Furthermore, with respect to the conventional alloys shown in Table 1 (Comparative Examples 1 to 5) and the samples shown in Table 2 (Reference Examples 1 to 6 and Examples 1 to 14), creep resistance characteristics ( The service temperature was compared. The results are shown in Table 5. Creepture characteristics are obtained by measuring the temperature until the sample breaks under a condition where a stress of 137 MPa is applied for 1000 hours, or by converting the breaking temperature of the sample into the conditions.

As is clear from Table 5, the samples of Reference Examples 1 to 6 and Examples 1 to 14 all have a high service temperature equal to or higher than that of the conventional alloys (Comparative Examples 1 to 5). You can see that it has. In particular, each of Examples 1 to 14 has a high service temperature (Example 1: 1344K (1071 ° C), Example 2: 1368K (1093 ° C), Example 3: 1375K (1102 ° C), and Example 4: 1372K. (1099 ° C), Example 5: 1379K (1106 ° C), Example 6: 1379K (1106 ° C), Example 7: 1379K (1106 ° C), Example 8: 1363K (1090 ° C), Example 9: 1358K (1085 ° C), Example 10: 1362K (1089 ° C), Example 11: 1361K (1088 ° C), Example 12: 1363K (1090 ° C), Example 13: 1366K (1093 ° C), Example 14: 1384K (1111 ° C.)).
Therefore, it can be seen that Examples 1 to 14 have a higher heat-resistant temperature as compared with the conventional Ni-based single crystal superalloy and have an excellent high-temperature strength.
In addition, in the Ni-based single crystal superalloy, if Ru increases more than necessary, the ε phase precipitates and the high-temperature strength decreases, so the content of Ru is within a range where the balance with other elements is not lost (for example, 4.1 wt% or more and 14.0 wt% or less).

  The present invention relates to a Ni-based single crystal superalloy, and more particularly to an improvement in a Ni-based single crystal superalloy for the purpose of improving creep characteristics.

  Examples of typical compositions of Ni-based single crystal superalloys that have been developed as materials for moving and stationary blades at high temperatures such as aircraft and gas turbines include those shown in Table 1.

  In the Ni-based single crystal superalloy, a solution treatment is performed at a predetermined temperature, and then an aging treatment is performed to obtain a Ni-based single crystal superalloy. This alloy is called a so-called precipitation hardening type alloy and has a form in which a γ ′ phase as a precipitation phase is precipitated in a γ phase as a parent phase.

Among the alloys listed in Table 1, CMSX-2 (manufactured by Canon Muskegon, see Patent Document 1) is the first generation alloy, and CMSX-4 (Cannon Maskegon, see Patent Document 2) is the second generation alloy. Rene'N6 (manufactured by General Electric, see Patent Document 3), CMSX-10K (Canon Maskegon, see Patent Document 4) are third generation alloys, 3B (General Electric Company, see Patent Document 5) ) Is called a fourth generation alloy.
U.S. Pat. No. 4,582,548 US Pat. No. 4,643,782 US Pat. No. 5,455,120 US Pat. No. 5,366,695 US Pat. No. 5,151,249

  CMSX-2, the first generation alloy, and CMSX-4, the second generation alloy, have a high eutectic γ 'phase even after high temperature solution treatment, although the creep strength at low temperatures is comparable. The creep strength at high temperatures is inferior to that of the third generation alloy.

  Further, the above-mentioned third generation Rene'N6 and CMSX-10K are alloys aiming at improving the creep strength at a higher temperature than the second generation alloys. However, since the composition ratio of Re (5% by weight or more) exceeds the amount of Re solid solution in the parent phase (γ phase), excess Re combines with other elements to form a so-called TCP phase (Topologically Close Packed) at high temperatures. Phase) and the amount of the TCP phase increases due to long-term use at high temperatures, resulting in a decrease in creep strength.

  In order to improve the creep strength of the Ni-based single crystal superalloy, it is effective to make the lattice constant of the precipitated phase (γ ′ phase) slightly smaller than the lattice constant of the parent phase (γ phase). Since the lattice constant of the phase largely fluctuates depending on the composition ratio of the constituent elements of the alloy, there is a problem that it is difficult to improve the creep strength because fine adjustment of the lattice constant is difficult.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a Ni-based single crystal superalloy capable of preventing the precipitation of a TCP phase at a high temperature and improving the strength.

In order to achieve the above object, the present invention employs the following configuration.
In the Ni-based single crystal superalloy of the present invention, the components are in a weight ratio of Al: 5.0% by weight to 7.0% by weight, Ta: 4.0% by weight to 10.0% by weight, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 8.0 wt% or less The remainder has a composition comprising Ni and inevitable impurities.
In the Ni-based single crystal superalloy of the present invention, the components are in a weight ratio of Al: 5.0% by weight to 7.0% by weight, Ta: 4.0% by weight to 6.0% by weight, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 8.0 wt% or less The remainder has a composition comprising Ni and inevitable impurities.
In the Ni-based single crystal superalloy of the present invention, the components are in a weight ratio of Al: 5.0% by weight to 7.0% by weight, Ta: 4.0% by weight to 6.0% by weight, Mo: 2 0.9 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 8.0 wt% or less The remainder has a composition comprising Ni and inevitable impurities.
In the Ni-based single crystal superalloy of the present invention, the components are in a weight ratio of Al: 5.0% by weight to 7.0% by weight, Ta: 4.0% by weight to 10.0% by weight, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 7.0 wt% or less The remainder has a composition comprising Ni and inevitable impurities.
In the Ni-based single crystal superalloy of the present invention, the components are in a weight ratio of Al: 5.0% by weight to 7.0% by weight, Ta: 4.0% by weight to 6.0% by weight, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 7.0 wt% or less The remainder has a composition comprising Ni and inevitable impurities.
In the Ni-based single crystal superalloy of the present invention, the components are in a weight ratio of Al: 5.0% by weight to 7.0% by weight, Ta: 4.0% by weight to 6.0% by weight, Mo: 2 0.9 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 7.0 wt% or less The remainder has a composition comprising Ni and inevitable impurities.
In the Ni-based single crystal superalloy of the present invention, the components are in a weight ratio of Al: 5.0% by weight to 7.0% by weight, Ta: 4.0% by weight to 10.0% by weight, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.6 wt% or more and 7.0 wt% or less The remainder has a composition comprising Ni and inevitable impurities.
In the Ni-based single crystal superalloy of the present invention, the components are in a weight ratio of Al: 5.0% by weight to 7.0% by weight, Ta: 4.0% by weight to 6.0% by weight, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.6 wt% or more and 7.0 wt% or less The remainder has a composition comprising Ni and inevitable impurities.
In the Ni-based single crystal superalloy of the present invention, the components are in a weight ratio of Al: 5.0% by weight to 7.0% by weight, Ta: 4.0% by weight to 6.0% by weight, Mo: 2 0.9 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.6 wt% or more and 7.0 wt% or less The remainder has a composition comprising Ni and inevitable impurities.

  According to the Ni-based single crystal superalloy described above, the addition of Ru suppresses the precipitation of the TCP phase that causes a decrease in strength when used at high temperatures. In addition, by setting the composition ratio of other constituent elements in an optimum range, it is possible to optimize the lattice constant of the parent phase (γ phase) and the lattice constant of the precipitated phase (γ ′ phase). . As a result, the strength at high temperature can be improved. Moreover, since the Ru composition ratio is 4.1 wt% or more and 8.0 wt% or less, precipitation of the TCP phase that causes a decrease in creep strength at the time of high temperature use is suppressed.

Further, in the Ni-based single crystal superalloy described above, the components are in a weight ratio of Al: 5.9 wt%, Ta: 5.9 wt%, Mo: 3.9 wt%, W: 5.9 wt%. %, Re: 4.9% by weight, Hf: 0.10% by weight, Cr: 2.9% by weight, Co: 5.9% by weight, Ru: 5.0% by weight, the balance being inevitable with Ni It is desirable to have a composition consisting of mechanical impurities.
According to the Ni-based single crystal superalloy having the above composition, the creep durability temperature at 137 MPa and 1000 hours can be set to 1344 K (1071 ° C.).

Further, in the Ni-based single crystal superalloy described above, the components are in a weight ratio of Co: 5.8 wt%, Cr: 2.9 wt%, Mo: 3.1 wt%, W: 5.8 wt%. %, Al: 5.8 wt%, Ta: 5.6 wt%, Ru: 5.0 wt%, Re: 4.9 wt%, Hf: 0.10 wt%, and the balance is inevitable with Ni It is desirable to have a composition consisting of mechanical impurities.
According to the Ni-based single crystal superalloy having the above composition, the creep durability temperature at 137 MPa and 1000 hours can be set to 1366 K (1093 ° C.).

In the Ni-based single crystal superalloy described above, the components are in a weight ratio of Co: 5.8 wt%, Cr: 2.9 wt%, Mo: 3.9 wt%, W: 5.8 wt%. %, Al: 5.8 wt%, Ta: 5.8 wt% (5.82 wt%) or 5,6 wt%, Ru: 6.0 wt%, Re: 4.9 wt%, Hf: 0 It is desirable to have a composition containing 10% by weight with the balance being Ni and inevitable impurities.
According to the Ni-based single crystal superalloy having the composition described above, the creep durability temperature at 137 MPa and 1000 hours can be set to 1375 K (1102 ° C.) or 1379 K (1106 ° C.).

Further, the Ni-based single crystal superalloy described above may further contain 0 wt% or more and 2.0 wt% or less of Ti by weight.
Further, the Ni-based single crystal superalloy described above may further contain 0% by weight to 4.0% by weight of Nb by weight ratio.

In addition, the Ni-based single crystal superalloy described above may include at least one of B, C, Si, Y, La, Ce, V, and Zr.
In this case, the individual components are, by weight ratio, B: 0.05% by weight or less, C: 0.15% by weight or less, Si: 0.1% by weight or less, Y: 0.1% by weight or less, La: It is preferable that they are 0.1 weight% or less, Ce: 0.1 weight% or less, V: 1 weight% or less, Zr: 0.1 weight% or less.

In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.8 wt% to 7.0 wt%, Ta: 4.0 wt% to 5.6 Wt% or less, Mo: 3.3 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0% to 0.50% by weight, Cr: 2.9% to 4.3% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 8%. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2.0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less Having.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 10.0 wt%. Wt% or less, Mo: 1.1 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0% by weight to 0.50% by weight, Cr: 2.9% by weight to 5.0% by weight, Co: 0% by weight to 9.9% by weight, Ru: 6.5% by weight to 8%. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2.0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less Having formed.
Further, in the Ni-based single crystal superalloy described above, it is more desirable that the components are in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 6.0 wt%. Wt% or less, Mo: 3.3 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0 wt% to 0.50 wt%, Cr: 2.0 wt% to 5.0 wt%, Co: 0 wt% to 9.9 wt%, Ru: 4.1 wt% to 8. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2.0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less Having.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.0% by weight or more and 7.0% by weight or less, Ta: 4.0% by weight or more and 5.6%. Wt% or less, Mo: 3.3 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0 wt% to 0.50 wt%, Cr: 2.0 wt% to 5.0 wt%, Co: 0 wt% to 9.9 wt%, Ru: 4.1 wt% to 8. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2.0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less Having.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 10.0 wt%. Wt% or less, Mo: 3.1 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0 wt% to 0.50 wt%, Cr: 2.0 wt% to 5.0 wt%, Co: 0 wt% to 9.9 wt%, Ru: 4.1 wt% to 8. 0 wt% or less, Nb: 4.0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.8 wt% to 7.0 wt%, Ta: 4.0 wt% to 10.0 wt%. Wt% or less, Mo: 3.1 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0 wt% to 0.50 wt%, Cr: 2.0 wt% to 5.0 wt%, Co: 0 wt% to 9.9 wt%, Ru: 4.1 wt% to 8. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: Composition comprising 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less A.
In the Ni-based single crystal superalloy described above, the components are more preferably in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 10.0 wt%. Wt% or less, Mo: 3.1 wt% or more and 4.5 wt% or less, W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf : 0% to 0.50% by weight, Cr: 2.9% to 4.3% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 8%. 0 wt% or less, Nb: 4.0 wt% or less, Ti: 2 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: Composition comprising 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less A.

Further, the Ni-based single crystal superalloy of the present invention more preferably has components in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta + Nb + Ti: 4.0 wt% or more and 10.0 wt% %: Mo: 3.3 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 to 0.50 wt%, Cr: 2.0 to 5.0 wt%, Co: 0 to 9.9 wt%, Ru: 4.1 to 8.0 wt% % By weight, B: 0.05% by weight or less, C: 0.15% by weight or less, Si: 0.1% by weight or less, Y: 0.1% by weight or less, La: 0.1% by weight or less, Ce : 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less.
Further, the Ni-based single crystal superalloy of the present invention more preferably has components in a weight ratio of Al: 5.0 wt% or more and 7.0 wt% or less, Ta + Nb + Ti: 4.0 wt% or more and 10.0 wt% %: Mo: 3.3 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 to 0.50 wt%, Cr: 2.0 to 5.0 wt%, Co: 0 to 9.9 wt%, Ru: 4.1 to 7.0 wt% % By weight, B: 0.05% by weight or less, C: 0.15% by weight or less, Si: 0.1% by weight or less, Y: 0.1% by weight or less, La: 0.1% by weight or less, Ce : 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less.
Further, the Ni-based single crystal superalloy of the present invention more preferably has components in a weight ratio of Al: 5.0% by weight to 7.0% by weight, Ta + Nb + Ti: 4.0% by weight to 10.0% by weight. %: Mo: 3.3 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 to 0.50% by weight, Cr: 2.0 to 5.0% by weight, Co: 0 to 9.9% by weight, Ru: 4.6 to 7.0% by weight % By weight, B: 0.05% by weight or less, C: 0.15% by weight or less, Si: 0.1% by weight or less, Y: 0.1% by weight or less, La: 0.1% by weight or less, Ce : 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% or less.

Further, the Ni-based single crystal superalloy of the present invention is the Ni-based single crystal superalloy described above, wherein 0.9937a1 when the lattice constant of the parent phase is a1 and the lattice constant of the precipitated phase is a2. ≤a2≤0.9958a1.
According to the Ni-based single crystal superalloy described above, the relationship between a1 and a2 is 0.9937a1 ≦ a2 ≦ 0.9958a1 where the lattice constant of the parent phase is a1 and the lattice constant of the precipitated phase is a2. Since the lattice constant a2 of the precipitated phase is minus 0.1% or less of the lattice constant a1 of the parent phase, the precipitated phase that precipitates in the parent phase is precipitated so as to continuously extend in the direction perpendicular to the load direction, Dislocation defects are less likely to move through the alloy structure under stress. As a result, it is possible to increase the strength at high temperatures as compared with conventional Ni-based single crystal superalloys.

Hereinafter, embodiments of the present invention will be described in detail.
The Ni-based single crystal superalloy of the present invention is an alloy containing components such as Al, Ta, Mo, W, Re, Hf, Cr, Co, and Ru, and Ni (remainder), and further containing inevitable impurities. is there.

In the Ni-based single crystal superalloy described above, for example, the composition ratio is Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 10.0 wt% or less, Mo: 1.1 Wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt %: Cr: 2.0 wt% or more, 5.0 wt% or less, Co: 0 wt% or more, 9.9 wt% or less, Ru: 4.1 wt% or more, 8.0 wt% or less, and the balance An alloy composed of Ni and inevitable impurities.
The Ni-based single crystal superalloy has a composition ratio of, for example, Al: 5.0% by weight or more and 7.0% by weight or less, Ta: 4.0% by weight or more and 6.0% by weight or less, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 8.0 wt% or less The balance is an alloy composed of Ni and inevitable impurities.
The Ni-based single crystal superalloy has a composition ratio of, for example, Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 6.0 wt% or less, Mo: 2 0.9 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 8.0 wt% or less The balance is an alloy composed of Ni and inevitable impurities.
The Ni-based single crystal superalloy has a composition ratio of, for example, Al: 5.0% by weight or more and 7.0% by weight or less, Ta: 4.0% by weight or more and 10.0% by weight or less, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 7.0 wt% or less The balance is an alloy composed of Ni and inevitable impurities.
The Ni-based single crystal superalloy has a composition ratio of, for example, Al: 5.0% by weight or more and 7.0% by weight or less, Ta: 4.0% by weight or more and 6.0% by weight or less, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 7.0 wt% or less The balance is an alloy composed of Ni and inevitable impurities.
The Ni-based single crystal superalloy has a composition ratio of, for example, Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 6.0 wt% or less, Mo: 2 0.9 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.1 wt% or more and 7.0 wt% or less The balance is an alloy composed of Ni and inevitable impurities.
The Ni-based single crystal superalloy has a composition ratio of, for example, Al: 5.0% by weight or more and 7.0% by weight or less, Ta: 4.0% by weight or more and 10.0% by weight or less, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.6 wt% or more and 7.0 wt% or less The balance is an alloy composed of Ni and inevitable impurities.
The Ni-based single crystal superalloy has a composition ratio of, for example, Al: 5.0% by weight or more and 7.0% by weight or less, Ta: 4.0% by weight or more and 6.0% by weight or less, Mo: 1 1 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.6 wt% or more and 7.0 wt% or less The balance is an alloy composed of Ni and inevitable impurities.
The Ni-based single crystal superalloy has a composition ratio of, for example, Al: 5.0 wt% or more and 7.0 wt% or less, Ta: 4.0 wt% or more and 6.0 wt% or less, Mo: 2 0.9 wt% to 4.5 wt%, W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.0 wt% 50 wt% or less, Cr: 2.0 wt% or more and 5.0 wt% or less, Co: 0 wt% or more and 9.9 wt% or less, Ru: 4.6 wt% or more and 7.0 wt% or less The balance is an alloy composed of Ni and inevitable impurities.

  Each of the above alloys has a γ phase (matrix) that is an austenite phase and a γ ′ phase (precipitation phase) that is an intermediate ordered phase dispersed and precipitated in the matrix. The γ ′ phase is mainly composed of an intermetallic compound represented by Ni 3 Al, and the γ ′ phase improves the high-temperature strength of the Ni-based single crystal superalloy.

Cr is an element excellent in oxidation resistance, and improves the high temperature corrosion resistance of the Ni-based single crystal superalloy.
The composition ratio of Cr is preferably in the range of Cr: 2.0 wt% or more and 5.0 wt% or less, more preferably 2.9 wt% or more and 5.0 wt% or less, and more preferably 2.9 wt% or more and 4 wt% or less. The range of .3% by weight or less is more preferable, and the range of 2.9% by weight is most preferable.
If the Cr composition ratio is less than 2.0% by weight, the desired high-temperature corrosion resistance cannot be ensured, which is not preferable. If the Cr composition ratio exceeds 5.0% by weight, precipitation of the γ ′ phase is suppressed. Since harmful phases such as σ phase and μ phase are generated and high temperature strength is lowered, it is not preferable.

In the presence of W and Ta, Mo dissolves in the γ phase, which is the parent phase, to increase the high temperature strength and contribute to the high temperature strength by precipitation hardening. Further, Mo greatly contributes to lattice misfit and dislocation network spacing (described later), which are characteristics of this alloy.
The composition ratio of Mo is preferably in the range of 1.1 wt% to 4.5 wt%, more preferably in the range of 2.9 wt% to 4.5 wt%, and more preferably 3.1 wt% to 4.5 wt%. A range of not more than wt%, or a range of not less than 3.3 wt% and not more than 4.5 wt% is more preferred, and most preferred is 3.1 wt% or 3.9 wt%.
If the Mo composition ratio is less than 1.1% by weight, the desired high-temperature strength cannot be secured. On the other hand, even if the Mo composition ratio exceeds 4.5% by weight, the high-temperature strength decreases, Is not preferable because the high-temperature corrosion resistance also decreases.

W improves the high-temperature strength by the action of solid solution strengthening and precipitation hardening in the presence of Mo and Ta as described above.
The W composition ratio is preferably in the range of 4.0 wt% to 10.0 wt%, and most preferably 5.9 wt% or 5.8 wt%.
If the W composition ratio is less than 4.0% by weight, the desired high-temperature strength cannot be ensured. This is not preferable, and if the W composition ratio exceeds 10.0% by weight, the high-temperature corrosion resistance decreases.

Ta improves the high-temperature strength by the action of solid solution strengthening and precipitation hardening in the presence of Mo and W as described above, and partly precipitates and hardens against the γ 'phase to improve the high-temperature strength. .
The composition ratio of Ta is preferably in the range of 4.0 wt% to 10.0 wt%, more preferably 4.0 wt% to 6.0 wt%, and more preferably 4.0 wt% to 5.6 wt%. A range of not more than wt% is more preferred, and most preferred is 5.6 wt% or 5.82 wt%.
If the Ta composition ratio is less than 4.0% by weight, the desired high-temperature strength cannot be ensured, which is not preferable. If the Ta composition ratio exceeds 10.0% by weight, a σ phase or μ phase is generated. This is not preferable because the high temperature strength decreases.

Al forms an intermetallic compound represented by Ni3Al) which forms a γ 'phase that combines with Ni and finely and uniformly disperses and precipitates in the matrix phase at a volume fraction of 60 to 70%. Improve strength.
The composition ratio of Al is preferably in the range of 5.0% by weight to 7.0% by weight, more preferably in the range of 5.8% by weight to 7.0% by weight, and more preferably 5.9% by weight or 5.8%. Most preferred is wt%.
If the Al composition ratio is less than 5.0% by weight, the amount of precipitation of the γ ′ phase becomes insufficient, and the desired high-temperature strength cannot be secured, which is not preferable. If the Al composition ratio exceeds 7.0% by weight, A large amount of coarse γ phase called a eutectic γ ′ phase is formed, so that solution treatment is impossible and high temperature strength cannot be secured.

Hf is a grain boundary segregation element and is unevenly distributed in the grain boundaries of the γ phase and the γ ′ phase to strengthen the grain boundaries, thereby improving the high temperature strength.
The composition ratio of Hf is preferably in the range of 0.01 wt% to 0.50 wt%, and most preferably 0.10 wt%.
If the Hf composition ratio is less than 0.01% by weight, the amount of precipitation of the γ ′ phase becomes insufficient, and the desired high-temperature strength cannot be ensured. However, if necessary, the composition ratio of Hf may be 0 wt% or more and less than 0.01 wt%. On the other hand, if the Hf composition ratio exceeds 0.50% by weight, it is not preferable because local melting may occur and the high-temperature strength may be reduced.

Co increases the solid solution limit of Al, Ta, and other parent phases at high temperatures, disperses and precipitates fine γ ′ phases by heat treatment, and improves high-temperature strength.
The composition ratio of Co is preferably in the range of 0.1 wt% to 9.9 wt%, and most preferably 5.8 wt%.
If the Co composition ratio is less than 0.1% by weight, the amount of precipitation of the γ ′ phase becomes insufficient, and the desired high-temperature strength cannot be ensured. However, if necessary, the Co composition ratio may be 0 wt% or more and less than 0.1 wt%. Further, if the Co composition ratio exceeds 9.9% by weight, the balance with other elements such as Al, Ta, Mo, W, Hf, and Cr will be lost, and a harmful phase will precipitate and the high temperature strength will decrease. It is not preferable.

Re dissolves in the γ phase, which is the parent phase, and improves high-temperature strength by solid solution strengthening. It also has the effect of improving corrosion resistance. On the other hand, when a large amount of Re is added, a TCP phase, which is a harmful phase, precipitates at a high temperature, and the high-temperature strength may be reduced.
The composition ratio of Re is preferably in the range of 3.1 wt% to 8.0 wt%, and most preferably 4.9 wt%.
If the Re composition ratio is less than 3.1% by weight, the solid solution strengthening of the γ phase is insufficient and the desired high-temperature strength cannot be ensured, and the Re composition ratio exceeds 8.0% by weight. In this case, the TCP phase is precipitated at high temperatures, and high high-temperature strength cannot be secured.

Ru suppresses the precipitation of the TCP phase, thereby improving the high temperature strength.
The composition ratio of Ru is in the range of 4.1 wt% to 8.0 wt%, or in the range of 4.1 wt% to 7.0 wt%, or 4.6 wt% to 7.0 wt%. % Or less is preferable, and 5.0% by weight, 6.0% by weight, or 7.0% by weight is most preferable.
When the composition ratio of Ru is less than 1.0% by weight, a TCP phase is precipitated at a high temperature, and a high high-temperature strength cannot be ensured. Furthermore, when the Ru composition ratio is less than 4.1% by weight, the high-temperature strength is lowered as compared with the case where the Ru composition ratio is 4.1% by weight or more. On the other hand, if the Ru composition ratio exceeds 14.0% by weight, the ε phase is precipitated and the high-temperature strength decreases, which is not preferable.

  In the present invention, by adjusting the composition ratio of Al, Ta, Mo, W, Hf, Cr, Co, Re, and Ni to an optimum one, the lattice constant of the γ phase and the lattice constant of the γ ′ phase are calculated. While setting the lattice misfit and the dislocation network spacing (described later) to the optimum ranges to improve the high-temperature strength, the addition of Ru can suppress the precipitation of the TCP phase. In particular, the production cost of the alloy can be reduced by setting the composition ratio of Al, Cr, Ta, and Mo as described above. Furthermore, the specific strength can be improved, and lattice misfit and dislocation network spacing can be set to optimum values.

  Further, in a use environment at a high temperature such as 1273 K (1000 ° C.) to 1373 K (1100 ° C.), the lattice constant of the crystal constituting the γ phase as the parent phase is a1, and the γ ′ phase as the precipitated phase is constituted. When the lattice constant of the crystal is a2, the relationship between a1 and a2 is preferably a2 ≦ 0.999a1. That is, the lattice constant a2 of the crystal of the precipitated phase is preferably minus 0.1% or less of the lattice constant a1 of the parent phase crystal. More preferably, the lattice constant a2 of the precipitated phase crystal is 0.9965 or less of the lattice constant a1 of the parent phase crystal. In this case, the relationship between a1 and a2 described above is a2 ≦ 0.9965a1. In the following description, the percentage of the crystal constant a2 of the precipitated phase relative to the lattice constant a1 of the parent phase crystal is referred to as “lattice misfit”.

When both lattice constants have such a relationship, when the precipitated phase is precipitated in the matrix by heat treatment, the precipitated phase precipitates so as to continuously extend in the direction perpendicular to the load direction. Therefore, dislocation defects are less likely to move in the alloy structure, and the creep strength is increased.
In order to make the relationship between the lattice constant a1 and the lattice constant a2 a2 ≦ 0.999a1, it is necessary to appropriately adjust the composition of the constituent elements constituting the Ni-based single crystal superalloy.

FIG. 1 shows the relationship between the lattice misfit and the time until creep rupture of the alloy (creep life).
In FIG. 1, it can be seen that if the lattice misfit is approximately −0.35% or less, the creep life substantially satisfies the required value (value indicated by a dotted line on the vertical axis in the figure). Therefore, in the present invention, a more preferable lattice misfit is set to −0.35% or less. In order to set the lattice misfit to −0.35% or less, it is necessary to adjust the composition ratio of other constituent elements while maintaining the Mo composition ratio high.

  According to the Ni-based single crystal superalloy described above, the addition of Ru suppresses the precipitation of the TCP phase that causes a decrease in creep strength during high temperature use. In addition, by setting the composition ratio of other constituent elements in the optimum range, it is possible to optimize the lattice constant of the parent phase (γ phase) and the lattice constant of the precipitated phase (γ 'phase). Become. As a result, the creep strength at high temperatures can be improved.

  The Ni-based single crystal superalloy described above may further contain Ti. In this case, the composition ratio of Ti is preferably in the range of 0% by weight to 2.0% by weight. If the composition ratio of Ti exceeds 2.0% by weight, a harmful phase precipitates and the high-temperature strength decreases, which is not preferable.

  The Ni-based single crystal superalloy described above may further contain Nb. In this case, the composition ratio of Nb is preferably 0% by weight or more and 4.0% by weight or less. If the composition ratio of Nb exceeds 4.0% by weight, a harmful phase precipitates and the high-temperature strength decreases, which is not preferable.

Alternatively, the high-temperature strength can be improved by setting the composition ratio of Ta, Nb, and Ti to 4.0% by weight or more and 10.0% by weight or less in the total of both (Ta + Nb + Ti).
In addition, the Ni-based single crystal superalloy described above may contain, for example, B, C, Si, Y, La, Ce, V, Zr, etc. in addition to the inevitable impurities. When containing at least one of B, C, Si, Y, La, Ce, V, and Zr, the composition ratio of each component is B: 0.05% by weight or less, C: 0.15% by weight or less Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: 0.1 wt% % Or less is preferable. If the composition ratio of the individual components exceeds the above range, a harmful phase precipitates and the high-temperature strength decreases, which is not preferable.

  In the Ni-based single crystal superalloy described above, the dislocation network spacing in the alloy is preferably 40 nm or less. The dislocation network indicates dislocations (displacement of atoms connected in a line) formed in a network in the alloy. The interval between the meshes is defined as the dislocation network interval. FIG. 2 shows the relationship between the distance between dislocation networks and the time until the alloy undergoes creep rupture (creep life).

  In FIG. 2, it can be seen that the creep life satisfies the required value (value indicated by the dotted line on the vertical axis in the figure) when the dislocation network interval is approximately 40 nm or less. Therefore, in the present invention, a preferable dislocation network interval is set to 40 nm or less. In order to set the dislocation network interval to 40 nm or less, it is necessary to adjust the composition ratio of other constituent elements while maintaining the Mo composition ratio high.

  FIG. 3 is a transmission electron micrograph of the Ni-based single crystal superalloy illustrating the dislocation network and the interval of the Ni-based single crystal superalloy of the present invention (Example 3 described later). FIG. 3 shows that the dislocation network spacing is 40 nm or less in the Ni-based single crystal superalloy of the present invention.

  In addition, in the conventional Ni-based single crystal superalloy, there are alloys that cause reverse distribution, but the Ni-based single crystal superalloy according to the present invention does not cause reverse distribution.

Next, an example is shown and the effect of the present invention is explained.
Various melts of Ni-based single crystal superalloys were prepared using a vacuum melting furnace, and a plurality of alloy ingots having different compositions were cast using the molten alloy. Table 2 shows the composition ratio of each alloy ingot (Reference Examples 1 to 6, Examples 1 to 14).

Next, solution treatment and aging treatment were performed on the alloy ingot, and the state of the alloy structure was observed with a scanning electron microscope (SEM). The solution treatment was held at 1573 K (1300 ° C.) for 1 hour, then heated to 1603 K (1330 ° C.) and held for 5 hours. Moreover, the aging treatment performed continuously the primary aging treatment hold | maintained at 1273K-1423K (1000 to 1150 degreeC) for 4 hours, and the secondary aging treatment hold | maintained at 1143K (870 degreeC) for 20 hours.
As a result, no TCP phase was confirmed in the tissues in each sample.

  Next, a creep test was performed on each sample subjected to solution treatment and aging treatment. In the creep test, the time until each sample (Reference Examples 1 to 6 and Examples 1 to 14) creep ruptured was measured as the lifetime under the conditions of temperature and stress shown in Table 3. Moreover, the value (%) of lattice misfit was also measured. These results are shown in Table 3. Furthermore, the lattice misfit (%) values of the conventional alloys shown in Table 1 (Comparative Examples 1 to 5) were also measured. These results are shown in Table 4.

  As is apparent from Table 3, the samples of Reference Examples 1 to 6 and Examples 1 to 14 have high strength even under high temperature conditions of 1273K (1000 ° C.) or higher. Recognize. In particular, Reference Example 5 in which the Ru composition ratio is 4.0% by weight, and Examples 1, 2, 4, 9, 10, and 11, Ru in which the Ru composition ratio is approximately 5.0% by weight. It can be seen that Examples 3 and 12, 13 in which the ratio is 6.0% by weight, and Example 14 in which the composition ratio of Ru is 7.0% by weight have high high-temperature strength.

  Further, as apparent from Tables 3 and 4, the lattice misfit of the comparative example is −0.35% or more, whereas the samples of Reference Examples 1 to 6 and Examples 1 to 14 are It can be seen that the lattice misfit is -0.35% or less.

  Furthermore, with respect to the conventional alloys shown in Table 1 (Comparative Examples 1 to 5) and the samples shown in Table 2 (Reference Examples 1 to 6 and Examples 1 to 14), creep resistance characteristics ( The service temperature was compared. The results are shown in Table 5. Creepture characteristics are obtained by measuring the temperature until the sample breaks under a condition where a stress of 137 MPa is applied for 1000 hours, or by converting the breaking temperature of the sample into the conditions.

  As is clear from Table 5, the samples of Reference Examples 1 to 6 and Examples 1 to 14 all have a high service temperature equal to or higher than that of the conventional alloys (Comparative Examples 1 to 5). You can see that it has. In particular, each of Examples 1 to 14 has a high service temperature (Example 1: 1344K (1071 ° C), Example 2: 1368K (1093 ° C), Example 3: 1375K (1102 ° C), and Example 4: 1372K. (1099 ° C), Example 5: 1379K (1106 ° C), Example 6: 1379K (1106 ° C), Example 7: 1379K (1106 ° C), Example 8: 1363K (1090 ° C), Example 9: 1358K (1085 ° C), Example 10: 1362K (1089 ° C), Example 11: 1361K (1088 ° C), Example 12: 1363K (1090 ° C), Example 13: 1366K (1093 ° C), Example 14: 1384K (1111 ° C.)).

  Therefore, it can be seen that Examples 1 to 14 have a higher heat-resistant temperature as compared with the conventional Ni-based single crystal superalloy and have an excellent high-temperature strength.

  In addition, in the Ni-based single crystal superalloy, if Ru increases more than necessary, the ε phase precipitates and the high-temperature strength decreases, so the content of Ru is within a range where the balance with other elements is not lost (for example, 4.1 wt% or more and 8.0 wt% or less).

It is a figure which shows the relationship between a lattice misfit and a creep life. It is a figure which shows the relationship between a dislocation network space | interval and a creep life. 3 is a transmission electron micrograph of a Ni-based single crystal superalloy illustrating the dislocation network and the interval between the Ni-based single crystal superalloys of the present invention.

Claims (24)

Ingredients by weight: Al: 5.0% to 7.0% by weight, Ta: 4.0% to 10.0% by weight, Mo: 1.1% to 4.5% by weight W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt%, Cr: 2.0 wt% % To 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14.0% by weight, with the balance being Ni and inevitable impurities Ni-based single crystal superalloy having Ingredients by weight: Al: 5.0% to 7.0% by weight, Ta: 4.0% to 6.0% by weight, Mo: 1.1% to 4.5% by weight W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt%, Cr: 2.0 wt% % To 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14.0% by weight, with the balance being Ni and inevitable impurities Ni-based single crystal superalloy having Components are by weight: Al: 5.0% to 7.0% by weight, Ta: 4.0% to 6.0% by weight, Mo: 2.9% to 4.5% by weight W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt%, Cr: 2.0 wt% % To 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14.0% by weight, with the balance being Ni and inevitable impurities Ni-based single crystal superalloy having The components are in a weight ratio of Al: 5.9 wt%, Ta: 5.9 wt%, Mo: 3.9 wt%, W: 5.9 wt%, Re: 4.9 wt%, Hf: 0.00. 4. The composition according to claims 1 to 3, comprising 10% by weight, Cr: 2.9% by weight, Co: 5.9% by weight, Ru: 5.0% by weight, with the balance being composed of Ni and inevitable impurities. The Ni-based single crystal superalloy according to any one of the above. The components are by weight ratio: Al: 5.8 wt%, Ta: 5.6 wt%, Mo: 3.1 wt%, W: 5.8 wt%, Re: 4.9 wt%, Hf: 0.00. 4. A composition comprising 10% by weight, Cr: 2.9% by weight, Co: 5.8% by weight, Ru: 5.0% by weight, and the balance comprising Ni and inevitable impurities. The Ni-based single crystal superalloy according to any one of the above. The components are by weight: Al: 5.8 wt%, Ta: 5.8 wt%, Mo: 3.9 wt%, W: 5.8 wt%, Re: 4.9 wt%, Hf: 0.00. 3. A composition comprising 10% by weight, Cr: 2.9% by weight, Co: 5.8% by weight, Ru: 6.0% by weight, and the balance comprising Ni and inevitable impurities. The Ni-based single crystal superalloy according to any one of the above. The Ni-based single crystal superalloy according to any one of claims 1 to 6, further containing 2.0% by weight or less of Ti by weight. The Ni-based single crystal superalloy according to any one of claims 1 to 7, further containing 4.0% by weight or less of Nb by weight ratio. The Ni-based single crystal superalloy according to any one of claims 1 to 8, which contains at least one of B, C, Si, Y, La, Ce, V, and Zr. By weight ratio, B: 0.05% by weight or less, C: 0.15% by weight or less, Si: 0.1% by weight or less, Y: 0.1% by weight or less, La: 0.1% by weight or less, Ce The Ni-based single crystal superalloy according to claim 9, wherein: 0.1 wt% or less, V: 1 wt% or less, and Zr: 0.1 wt% or less. Ingredients by weight: Al: 5.0% to 7.0% by weight, Ta: 4.0% to 10.0% by weight, Mo: 1.1% to 4.5% by weight W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt%, Cr: 2.0 wt% % To 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 10.0% to 14.0% by weight, Nb: 4.0% by weight or less, Ti: 2. 0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, The Ni group unit according to any one of claims 1 to 3, which contains Ce: 0.1 wt% or less, V: 1 wt% or less, and Zr: 0.1 wt% or less. Crystal superalloys. Components are by weight: Al: 5.8 wt% to 7.0 wt%, Ta: 4.0 wt% to 5.6 wt%, Mo: 3.3 wt% to 4.5 wt% W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt%, Cr: 2.9 wt% %: 4.3% by weight or less, Co: 0% by weight or more, 9.9% by weight or less, Ru: 4.1% by weight or more, 14.0% by weight or less, Nb: 4.0% by weight or less, Ti: 2. 0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, The Ni-based single crystal according to any one of claims 1 to 3, comprising Ce: 0.1 wt% or less, V: 1 wt% or less, and Zr: 0.1 wt% or less. Alloy. Ingredients by weight: Al: 5.0% to 7.0% by weight, Ta: 4.0% to 10.0% by weight, Mo: 1.1% to 4.5% by weight W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf: 0 wt% or more and 0.50 wt% or less, Cr: 2.9 wt% % To 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 6.5% to 14.0% by weight, Nb: 4.0% by weight or less, Ti: 2. 0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, The Ni-based single bond according to any one of claims 1 to 3, containing Ce: 0.1 wt% or less, V: 1 wt% or less, and Zr: 0.1 wt% or less. Superalloys. Components are by weight: Al: 5.0% to 7.0% by weight, Ta: 4.0% to 6.0% by weight, Mo: 3.3% to 4.5% by weight W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt%, Cr: 2.0 wt% % To 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14.0% by weight, Nb: 4.0% by weight or less, Ti: 2. 0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, The Ni-based single crystal according to any one of claims 1 to 3, which contains Ce: 0.1 wt% or less, V: 1 wt% or less, and Zr: 0.1 wt% or less. Alloy. Components are by weight: Al: 5.0% to 7.0% by weight, Ta: 4.0% to 5.6% by weight, Mo: 3.3% to 4.5% by weight W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt%, Cr: 2.0 wt% % To 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14.0% by weight, Nb: 4.0% by weight or less, Ti: 2. 0 wt% or less, B: 0.05 wt% or less, C: 0.15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, The Ni-based single crystal according to any one of claims 1 to 3, which contains Ce: 0.1 wt% or less, V: 1 wt% or less, and Zr: 0.1 wt% or less. Alloy. Ingredients by weight: Al: 5.0% to 7.0% by weight, Ta: 4.0% to 10.0% by weight, Mo: 3.1% to 4.5% by weight W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt%, Cr: 2.0 wt% % To 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14.0% by weight, Nb: 4.0% by weight or less, Ti: 2% % Or less, B: 0.05% by weight or less, C: 0.15% by weight or less, Si: 0.1% by weight or less, Y: 0.1% by weight or less, La: 0.1% by weight or less, Ce: The Ni-based single crystal superstructure according to any one of claims 1 to 3, comprising 0.1 wt% or less, V: 1 wt% or less, and Zr: 0.1 wt% or less. Gold. Ingredients by weight: Al: 5.8 wt% to 7.0 wt%, Ta: 4.0 wt% to 10.0 wt%, Mo: 3.1 wt% to 4.5 wt% W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt%, Cr: 2.0 wt% % To 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14.0% by weight, Nb: 4.0% by weight or less, Ti: 2% % Or less, B: 0.05% by weight or less, C: 0.15% by weight or less, Si: 0.1% by weight or less, Y: 0.1% by weight or less, La: 0.1% by weight or less, Ce: The Ni-based single crystal superstructure according to any one of claims 1 to 3, comprising 0.1 wt% or less, V: 1 wt% or less, and Zr: 0.1 wt% or less. Gold. Ingredients by weight: Al: 5.0% to 7.0% by weight, Ta: 4.0% to 10.0% by weight, Mo: 3.1% to 4.5% by weight W: 4.0 wt% or more and 10.0 wt% or less, Re: 3.1 wt% or more and 8.0 wt% or less, Hf: 0 wt% or more and 0.50 wt% or less, Cr: 2.9 wt% % To 4.3% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14.0% by weight, Nb: 4.0% by weight or less, Ti: 2% % Or less, B: 0.05% by weight or less, C: 0.15% by weight or less, Si: 0.1% by weight or less, Y: 0.1% by weight or less, La: 0.1% by weight or less, Ce: The Ni-based single crystal superstructure according to any one of claims 1 to 3, comprising 0.1 wt% or less, V: 1 wt% or less, and Zr: 0.1 wt% or less. Gold. Components are by weight: Al: 5.0% to 7.0% by weight, Ta + Nb + Ti: 4.0% to 10.0% by weight, Mo: 3.3% to 4.5% by weight W: 4.0 wt% to 10.0 wt%, Re: 3.1 wt% to 8.0 wt%, Hf: 0 wt% to 0.50 wt%, Cr: 2.0 wt% % To 5.0% by weight, Co: 0% to 9.9% by weight, Ru: 4.1% to 14.0% by weight, B: 0.05% by weight or less, C: 0.00%. 15 wt% or less, Si: 0.1 wt% or less, Y: 0.1 wt% or less, La: 0.1 wt% or less, Ce: 0.1 wt% or less, V: 1 wt% or less, Zr: Ni-based single crystal superalloy containing 0.1% by weight. 20. The Ni-based single crystal superalloy according to any one of claims 1 to 19, wherein a2 ≦ 0.999a1 when the lattice constant of the matrix phase is a1 and the lattice constant of the precipitated phase is a2. 21. The Ni-based single crystal superalloy according to claim 20, wherein a lattice constant a2 of the crystal of the precipitated phase is 0.9965 or less of a lattice constant a1 of the crystal of the parent phase. The lattice constant a2 of the crystal of the precipitated phase is 0.9965 or less of the lattice constant a1 of the matrix of the parent phase, contains Re and Ru in the components, and Mo: 2.9% by weight or more 4 Ni-based single crystal superalloy containing 5 wt% or less. The lattice constant a2 of the crystal of the precipitated phase is 0.9965 or less of the lattice constant a1 of the parent phase crystal, and Mo: 2.9% by weight to 4.5% by weight, Re: A Ni-based single crystal superalloy containing 3.1 wt% or more and 8.0 wt% or less and Ru: 4.1 wt% or more and 14.0 wt% or less. The Ni-based single crystal superalloy according to any one of claims 1 to 23, wherein a transition network interval in the alloy is 40 nm or less.

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