KR102139177B1 - Wrought nickel base superalloys for forging having excellent creep property and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a nickel-based super-heat-resistant alloy for annealing with excellent creep properties, and a nickel-based super-heat-resistant alloy for annealing with excellent creep properties according to an embodiment of the present invention is 17.0 to 21.0% by weight of chromium (Cr), 7.0 to 11.0 wt% cobalt (Co), 5.0-9.5 wt% molybdenum (Mo), 1.5-3.5 wt% titanium (Ti), 0.8-2.5 wt% aluminum (Al), 0.05-0.26 wt% silicon ( Si), 0.04 to 0.08% by weight of carbon (C), 0.0001 to 0.060% by weight of lanthanum (La), balance nickel (Ni), and unavoidable impurities.

Description

Nickel base super heat-resistant alloy with excellent creep characteristics and its manufacturing method{WROUGHT NICKEL BASE SUPERALLOYS FOR FORGING HAVING EXCELLENT CREEP PROPERTY AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a nickel-based super-heat-resistant alloy for annealing excellent in creep characteristics and a method for manufacturing the same, and more specifically, by optimizing the composition ratio of the nickel-base super-heat-resistant alloy, the nickel-based super-heat-resistant alloy for annealing excellent in creep characteristics at high temperature and It relates to a manufacturing method.

Nickel-based super-heat-resistant alloy for annealing contains a lot of chromium (Cr), so it is not only excellent in oxidation resistance and corrosion resistance at high temperatures, but also in high temperature mechanical properties, particularly high temperature creep properties, by using solid solution strengthening and precipitation strengthening. It is an alloy made with the main purpose of withstanding use in harsh high temperature environments such as steam or corrosion.

Super heat-resistant alloy is an alloy made with the main purpose of withstanding use at high temperature, and heat-resistant steel refers to an alloy steel having stable mechanical properties and good corrosion resistance even at high temperatures.

Nimonic 263 and Alloy 617 alloys are commonly used alloys known as alloys having excellent oxidation resistance and creep properties in conventionally developed nickel-based super-heat-resistant alloys for annealing, and they can be used for a long time with excellent phase stability up to approximately 650°C. In particular, in the case of power generation facilities such as A-USC (Advanced-Ultra supercritical), it is expected that the temperature of the main steam will increase from 650°C to 700 to 760°C for carbon dioxide reduction and energy efficiency. It is difficult to use silver at a temperature of 700 to 760°C, and a new alloy with excellent creep properties is required.

Many nickel based superalloys are precipitation strengthening type alloys. When manufacturing this type of alloy, a small amount of titanium (Ti) or aluminum (Al) is added or a small amount of neobium (Nb) is further added, and Ni ₃ (hereinafter referred to as gamma prime phase) is called A precipitation phase composed of Ni ₃ Nb called Al, Ti) and/or gamma double-prime phase (indicated by γ ") is formed finely and coherently in an austenite (hereinafter referred to as γ) matrix. And strengthen the system to obtain satisfactory high temperature strength.

Korean Open Patent Publication No. 10-2011-0114928

An object of the present invention is to provide a nickel-based super heat-resistant alloy for annealing excellent in creep characteristics used in harsh environments by controlling alloy components and controlling process conditions and a method for manufacturing the same.

Nickel-based super-heat-resistant alloy for annealing excellent creep characteristics according to an embodiment of the present invention is 17.0 to 21.0% by weight of chromium (Cr); 7.0 to 11.0% by weight of cobalt (Co); 5.0 to 9.5% by weight of molybdenum (Mo); 1.5 to 3.5% by weight of titanium (Ti); 0.8 to 2.5% by weight of aluminum (Al); 0.05 to 0.26% by weight of silicon (Si); 0.04 to 0.08% by weight of carbon (C); 0.0001 to 0.060% by weight of lanthanum (La); Balance nickel (Ni); And unavoidable impurities.

In addition, the nickel-based super-heat-resistant alloy may further include 0.003 to 0.007% by weight of boron (B).

In addition, the nickel-based super-heat-resistant alloy may further include 0.01 to 5.0% by weight of tungsten (W).

In addition, the nickel-based super-heat-resistant alloy may have an average energy level of d-orbital electrons of 0.93 to 0.95.

In addition, the nickel-based super-heat-resistant alloy may have a creep life of 1500 to 2500 hours at a temperature of 760°C and a load of 283 Mpa.

A method of manufacturing a nickel-based super heat-resistant alloy for annealing having excellent creep characteristics according to an embodiment of the present invention includes 17.0 to 21.0% by weight of chromium (Cr); 7.0 to 11.0% by weight of cobalt (Co); 5.0 to 9.5% by weight of molybdenum (Mo); 1.5 to 3.5% by weight of titanium (Ti); 0.8 to 2.5% by weight of aluminum (Al); 0.05 to 0.26% by weight of silicon (Si); 0.04 to 0.08% by weight of carbon (C); 0.0001 to 0.060% by weight of lanthanum (La); Balance nickel (Ni); And mixing and dissolving a raw material composed of unavoidable impurities. Molding the mixed and dissolved alloy; And heat-treating the molded alloy.

In addition, the step of heat-treating the molded alloy is a solution heat treatment at 1200 to 1280 ℃; And aging at 700 to 850°C.

In addition, the method of manufacturing the nickel-based super-heat-resistant alloy further includes a cooling step, and the cooling step may be performed at 1 to 40° C./s.

Nickel-based super-heat-resistant alloy having excellent creep properties according to an embodiment of the present invention can provide a nickel-based super-heat-resistant alloy with improved creep life at a low cost, through which a nickel group with excellent creep properties compared to cost is excellent. Super heat-resistant alloy can be provided.

1 is a flowchart illustrating a method for manufacturing a nickel-based super heat-resistant alloy for annealing having excellent creep characteristics according to an embodiment of the present invention.
Figure 2 shows the creep strain of the nickel-based super-heat-resistant alloy prepared in Examples 1 to 7 and Comparative Examples 1 to 5 with respect to time at a temperature of 760 ℃ and 283Mpa load.
Figure 3 shows the creep life according to the average energy level of the d-orbital electrons of the nickel-based super-heat-resistant alloy prepared in Examples 1 to 7 and Comparative Examples 1 to 5.
Figure 4 shows the creep life according to the lanthanum weight% of the nickel-based super-heat-resistant alloy prepared in Example 4 and Example 5.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for a clearer description, and elements indicated by the same reference numerals in the drawings are the same elements. In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions. In addition, "including" a component throughout the specification means that other components may be further included rather than excluding other components, unless specifically stated to the contrary.

Creep For training with excellent properties Nickel base Super heat-resistant alloy

Hereinafter, a component system and a component range of a nickel-based super-heat-resistant alloy for annealing having excellent creep characteristics according to the present invention will be described.

Chromium (Cr): 17.0 to 21. 0 %

Chromium (Cr) is an essential solid solution strengthening element for improving oxidation resistance, corrosion resistance, and alloy strength in a nickel-based super-heat-resistant alloy, and is an element having oxidation resistance. In addition, chromium is precipitated as a carbide in combination with carbon, thereby increasing the high temperature strength. As described above, chromium (Cr) plays a role in improving corrosion resistance and oxidation resistance in a super-heat-resistant alloy, but when excessively added, carbide or TCP (Topologically Close Packed) phase may be generated.

Therefore, it is preferable that the chromium (Cr) is added in a content ratio of 17.0 to 21.0 wt% of the total weight of the nickel-base superheat-resistant alloy for annealing excellent in creep characteristics according to the present invention. When the content of chromium (Cr) is less than 17.0% by weight, problems in oxidation resistance and corrosion resistance may occur. Conversely, when the content of chromium (Cr) exceeds 21.0% by weight, the formation of a detrimental TCP phase that adversely affects the mechanical properties when exposed to a high temperature for a long time is promoted, and as a result, creep properties may be rapidly reduced.

Cobalt (Co): 7.0 to 11.0%

Cobalt (Co) is an element that plays a role in improving the high-temperature characteristics of super-heat-resistant alloys such as solid solution strengthening, that is, creep characteristics, and high-temperature by reducing the layered defect energy of the base together with solid solution strengthening of the γ phase, the base of the nickel-based super-heat-resistant alloy. It is known to improve strength. If the content of cobalt is less than 7.0% by weight, there is a problem that creep characteristics are lowered, and when it exceeds 11.0% by weight, a brittle TCP phase is precipitated, thereby deteriorating the high temperature stability and creep characteristics of the alloy.

Molybdenum (Mo): 5.0 to 9.5%

Molybdenum (Mo) is a major element that forms a TCP phase with chromium (Cr) and tungsten (W), although it contributes to improving the high temperature properties of the alloy through solid solution strengthening of the γ phase, which is a nickel matrix, and when it is excessively contained It lowers the phase stability and oxidation resistance.

The molybdenum (Mo) is preferably added in a content ratio of 5.0 to 9.5% by weight of the total weight of the nickel-based super-heat-resistant alloy according to the present invention. When the addition amount of molybdenum (Mo) is less than 5.0% by weight, it is difficult to expect a solid solution strengthening effect due to the small addition amount, and this causes a problem of deteriorating creep characteristics. Conversely, when the amount of molybdenum (Mo) exceeds 9.5% by weight, a TCP phase called a μ-phase is formed to degrade creep properties and oxidation resistance.

Titanium (Ti): 1.5 to 3.5%

Titanium (Ti) mainly acts to form MC carbides and suppress the expansion of alloy grains, and, like aluminum, combines with nickel to promote the precipitation of the γ'phase of Ni ₃ (Al, Ti) to improve creep fracture strength It is an element that contributes to grain boundary strengthening. In addition, titanium is an element that improves the high temperature corrosion resistance of the alloy. On the other hand, if the titanium content is excessively present, the high-temperature stability of the γ'phase is reduced to cause precipitation of the η phase, thereby reducing creep characteristics along with strength, ductility, toughness, and long-term phase stability.

The titanium is preferably added in a content ratio of 1.5 to 3.5% by weight of the total weight in the nickel-based super-heat-resistant alloy for annealing having excellent creep characteristics according to an embodiment of the present invention. When the content of titanium is less than 1.5% by weight, the precipitation strengthening effect of the nickel-based super-heat-resistant alloy may be insignificant, and when the content of titanium exceeds 3.5% by weight, the η phase precipitates, which significantly deteriorates creep properties.

Aluminum (Al): 0.8 to 2.5%

Aluminum (Al) is a constituent element of γ', which is the main strengthening phase of the nickel-based super-heat-resistant alloy, and promotes precipitation of the Ni ₃ Al γ'phase, thereby improving creep strength and contributing to oxidation resistance.

The aluminum (Al) is preferably added in a content ratio of 0.8 to 2.5% by weight of the total weight of the nickel-based super heat-resistant alloy according to the present invention. When the amount of aluminum (Al) added is less than 0.8% by weight, sufficient precipitation hardening cannot be obtained. Conversely, when the addition amount of aluminum (Al) exceeds 2.5% by weight, there is a problem in that workability deteriorates due to excessive precipitation of the γ'phase, and the formation of the TCP phase is promoted to decrease creep characteristics.

Silicon (Si): 0.05% to 0.26%

Silicon (Si) serves to improve the oxidation resistance of the alloy. The silicon (Si) is preferably added in a content ratio of 0.05 to 0.26% by weight of the total weight of the nickel-based super-heat-resistant alloy according to the present invention. When the addition amount of silicon (Si) is less than 0.05% by weight, it may be difficult to properly exhibit the effect of improving oxidation resistance due to a small relationship of the addition amount. Conversely, when the amount of silicon (Si) is added in excess of 0.26% by weight, there is a problem in that creep properties are rapidly reduced by promoting precipitation on the TCP and lowering the melting point of the alloy.

Carbon (C): 0.04 to 0.08%

Carbon (C) is combined with titanium (Ti), chromium (Cr) and molybdenum (Mo) to form MC. It is an element that improves creep properties by forming carbides of M6C and M23C6 inside grain boundaries and grains. In addition, carbon suppresses the expansion of crystal grains and contributes to the improvement of high temperature strength.

The carbon (C) is preferably added in a content ratio of 0.04 to 0.08% by weight of the total weight of the nickel-based superheat-resistant alloy according to the present invention. When the amount of carbon (C) added is less than 0.04% by weight, sufficient carbides are not formed, and thus it is difficult to achieve a strength improvement effect. Conversely, when the addition amount of carbon (C) exceeds 0.08% by weight, Ti and MC or M ₆ C carbides forming W, Mo, and γ'phases contributing to the known solid solution strengthening are formed, and consequently W, By consuming Mo and Ti, the known solid solution strengthening and γ'precipitation strengthening effects are reduced, thereby reducing creep characteristics. Further, by forming a continuous M ₂₃ C ₆ or M ₆ C type carbide in the form of a film on the grain boundaries, rather, the grain boundary strength is lowered.

Lanthanum (La): 0.0001 to 0.060%

Lanthanum (La) exists segregated at the grain boundaries, and serves as a diffusion barrier for oxygen moving through the grain boundaries, thereby increasing oxidation resistance. In addition, it is also possible to improve creep characteristics by lowering the content of sulfur (S), which lowers the creep characteristics of the super heat-resistant alloy for annealing.

The lanthanum (La) is preferably added at a content ratio of 0.0001 to 0.060% by weight of the total weight of the nickel-based superheat-resistant alloy according to the present invention. When the amount of lanthanum (La) added is less than 0.0001% by weight, it may be difficult to properly exhibit the above effects due to a slight relationship. Conversely, when the amount of lanthanum (La) added exceeds 0.060% by weight, the local strain of the grain boundary is increased to deteriorate the stability and eventually the grain boundary slippage is activated to decrease creep life.

Nickel-based super-heat-resistant alloy for annealing excellent creep characteristics according to an embodiment of the present invention may further include 0.003 to 0.007% by weight of boron (B).

In addition, the nickel-based super-heat-resistant alloy for annealing excellent in creep characteristics according to an embodiment of the present invention may further include 0.01 to 5.0% by weight of tungsten (W).

Description of the component system and range of components of boron and tungsten in a nickel-based super heat-resistant alloy for annealing having excellent creep characteristics according to the present invention is as follows.

Boron (B): 0.003 to 0.007%

Boron (B) is segregated in the grain boundary to improve grain boundary strength, and is an element contributing to grain refinement, thereby inhibiting grain growth to improve creep characteristics. However, if it is excessively present in the alloy, the local melting temperature of the alloy may be reduced to cause local melting in the vicinity of the process structure during solution heat treatment, and boride may be formed on the grain boundaries, thereby reducing creep characteristics.

The boron (B) is preferably added in a content ratio of 0.003 to 0.007% by weight of the total weight of the nickel-based super-heat-resistant alloy according to the present invention. When the amount of boron (B) added is less than 0.003% by weight, it is difficult to properly exhibit the effect of improving creep properties due to the small amount of addition. Conversely, when the amount of boron (B) added exceeds 0.007% by weight, it may be a creep property with a problem that the oxidation resistance decreases due to interaction with lanthanum (La), which improves oxidation resistance.

Tungsten (B): 0.01 to 5.0%

Tungsten (W) is an element with a very low diffusion coefficient in nickel, which serves to enhance the solid solution strengthening and the melting point of the matrix, thereby improving high temperature strength and creep characteristics. In addition, tungsten is a major element that forms M6C and MC carbides together with chromium and molybdenum, and strengthens grain boundaries. On the other hand, if it is added in excess, it forms a vulnerable TCP phase and sharply degrades the creep characteristics.

The tungsten (W) is preferably added in a content ratio of 0.1 to 5.0% by weight of the total weight of the super heat-resistant alloy according to the present invention. When the added amount of tungsten (W) is less than 0.1% by weight, difficulty in properly exerting the above effects may be followed. Conversely, when the amount of addition of tungsten (W) exceeds 5.0% by weight, creep characteristics may deteriorate due to formation of a weak TCP phase.

The nickel-based super-heat-resistant alloy for annealing excellent in creep characteristics according to an embodiment of the present invention may have a d-electron orbit average energy level of 0.93 to 0.95.

The average energy level of d-orbital electrons in an annealing nickel-based superalloy having excellent creep characteristics according to an embodiment of the present invention can be calculated through Equation 1 below.

<Equation 1>

: d-궤도 전자의 평균 에너지 레벨

: Average energy level of d-orbit electron

X _Cr, X _Co, X _Mo, X _Ti, X _Al, X _Si, X _W, X _Ni : atomic ratio of each element

When the range of the average energy level of d-orbital electrons in the nickel-based superalloy is out of 0.93 to 0.95, creep life may be deteriorated.

Creep For training with excellent properties Nickel base Manufacturing method of super heat-resistant alloy

1 is a flow chart of a method of manufacturing a nickel-based super heat-resistant alloy for annealing excellent creep characteristics according to an embodiment of the present invention.

Referring to Figure 1, the method of manufacturing a nickel-based super-heat-resistant alloy for annealing excellent creep characteristics according to an embodiment of the present invention is 17.0 to 21.0% by weight of chromium (Cr), 7.0 to 11.0% by weight of cobalt (Co), 5.0 to 9.5% by weight of molybdenum (Mo), 2.0 to 3.5% by weight of titanium (Ti), 0.8 to 1.5% by weight of aluminum (Al), 0.15% to 0.26% by weight of silicon (Si), 0.04 to 0.08% Mixing and dissolving a raw material composed of% carbon (C), 0.003 to 0.007% by weight of boron (B), 0.0001 to 0.060% by weight of lanthanum (La), balance nickel (Ni), and unavoidable impurities; Processing the mixed and molten alloy; And heat-treating the molded alloy.

First, 17.0 to 21.0% by weight of chromium (Cr), 7.0 to 11.0% by weight of cobalt (Co), 5.0 to 9.5% by weight of molybdenum (Mo), 2.0 to 3.5% by weight of titanium (Ti), 0.8 to 1.5% by weight % Aluminum (Al), 0.15 to 0.26% by weight silicon (Si), 0.04 to 0.08% by weight carbon (C), 0.003 to 0.007% by weight boron (B), 0.0001 to 0.060% by weight lanthanum (La) , The step of mixing and dissolving the raw material composed of the remaining nickel (Ni), and inevitable impurities will be described.

The form of the raw material is powder, strip, bar, plate, thin film, rod, wire, tube, shape ) And ingots, and any shape including the shape may be used, preferably in the form of powder.

17.0 to 21.0 wt% Chromium (Cr), 7.0 to 11.0 wt% Cobalt (Co), 5.0 to 9.5 wt% Molybdenum (Mo), 2.0 to 3.5 wt% Titanium (Ti), 0.8 to 1.5 wt% Aluminum (Al), 0.15 to 0.26 wt% silicon (Si), 0.04 to 0.08 wt% carbon (C), 0.003 to 0.007 wt% boron (B), 0.0001 to 0.060 wt% lanthanum (La), balance In the step of mixing and dissolving the raw material composed of nickel (Ni), and inevitable impurities, the dissolving method may be performed by a vacuum induction melting method, but the dissolution method is not limited thereto. If the vacuum induction melting method is used, the metal can be dissolved in a vacuum to prevent impurities from entering.

Next, the step of molding the mixed and dissolved alloy will be described.

In the step of forming the mixed and dissolved alloy, the method of processing may include at least one of hot rolling, cold rolling, casting, and forging.

In the step of processing the mixed and molten alloy, when it is processed by hot rolling, it is preferable to perform hot rolling at a reduction ratio of 40 to 80% at 1100 to 1250°C. When the hot rolling temperature is less than 1100°C, there is a problem that cracking may occur due to hot rolling. Conversely, when the hot rolling temperature exceeds 1250°C, there is a problem in controlling the microstructure by coarsening the grains of the alloy. In addition, when the reduction ratio of hot rolling is less than 40%, it is difficult to secure a uniform and fine structure. Conversely, when the reduction ratio of hot rolling exceeds 80%, there is a problem in that the rolling process time increases and productivity decreases.

Next, the step of heat-treating the alloy will be described.

The heat treatment of the alloy may include a solution heat treatment at 1100 to 1200°C, and an aging treatment at 700 to 850°C. The aging treatment step may be selectively performed according to the composition of the alloy.

For example, the nickel-based alloy formed in the previous step is subjected to a solution heat treatment that is maintained at a high temperature region of 1100 to 1200°C for 30 to 240 minutes, followed by an aging treatment at a medium temperature region of 700 to 850 °C for 4 to 8 hours. Can be performed.

At this time, if the solution heat treatment is carried out outside of 1100 ~ 1200 ℃, there is a problem that all the precipitates are not dissolved or have the desired properties due to grain coarsening phenomenon. Here, the solution heat treatment is preferably performed for 30 to 240 minutes, in which the homogenization treatment is sufficiently performed in the alloy, that is, the carbide and γ′ precipitated phase in the alloy are sufficiently dissolved and solidified, but crystal grain growth does not occur.

On the other hand, the aging treatment is to uniformly distribute the γ′ precipitated phase of the alloy in the matrix, and precipitate carbides at the grain boundaries to induce aging treatment to occur sufficiently so that there is no change in structure even when exposed in the same aging treatment temperature range. It is preferably carried out at 700 to 850°C for 4 to 8 hours.

In addition, the method of manufacturing a nickel-based super-heat-resistant alloy according to an embodiment of the present invention further includes a cooling step, and the cooling step may be performed at 1 to 40°C/s. In the cooling step, cooling may be performed to room temperature by water cooling or air cooling, and the normal temperature may be 1 to 40°C, but is not limited thereto.

Example

Specimen preparation

Nickel-based super-heat-resistant alloys of Examples 1 to 7 and Comparative Examples 1 to 5 were prepared with the composition of Table 1.

Cr (% by weight) Co (% by weight) Mo (% by weight) Ti (% by weight) Al (% by weight) Si (% by weight) C (% by weight) B (% by weight) La (% by weight) W (% by weight) Ni (% by weight) Example 1 18 8 8.5 1.6 2.4 0.15 0.06 0.005 0 bal. Example 2 18 8 6 1.6 2.4 0.15 0.06 0.005 0 4.0 bal. Example 3 20 10 8.5 3.0 1.0 0.25 0.06 0.005 0 bal. Example 4 20 10 8.5 3.0 1.0 0.25 0.06 0.005 0.02 bal. Example 5 20 10 8.5 3.0 1.0 0.25 0.06 0.005 0.06 bal. Example 6 20 10 8.5 2.0 2.0 0.05 0.06 0.005 0 bal. Example 7 18 8 8.5 1.8 2.7 0.15 0.06 0.005 0 bal. Comparative Example 1 18 8 8.5 1.0 1.5 0.15 0.06 0.005 0 bal. Comparative Example 2 22 12 8.5 1.0 1.5 0.15 0.06 0.005 bal. Comparative Example 3 18 8 8.5 1.5 2.25 0.15 0.06 0.005 0 bal. Comparative Example 4 20 10 8.5 2.0 1.5 0.15 0.06 0.005 bal. Comparative Example 5 22 12 8.5 1.5 2.25 0.15 0.06 0.005 bal.

The nickel-based super-heat-resistant alloys of Examples 1 to 7 and Comparative Examples 1 to 5 were mixed and dissolved in the composition, molded at a reduction rate of 60% at a temperature of 1200°C, and subjected to a solution heat of 1150°C. Solution was performed for 60 minutes, and then air-cooled to cool to room temperature.

FIG. 2 shows creep strain rates over time by evaluating creep properties at 760° C. temperature and 283 MPa load conditions to compare the nickel-base superheat-resistant alloys prepared in Examples 1 to 7 and Comparative Examples 1 to 5 with conventional commercial alloys. It is shown.

Referring to Figure 2, it can be seen that the nickel-based super-heat-resistant alloy prepared in Examples 1 to 7 exhibits an increased creep life compared to the nickel-based super-heat-resistant alloy prepared in Comparative Examples 1 to 5. have. In particular, it can be seen that the nickel-based super-heat-resistant alloys prepared in Examples 4 and 5 exhibit creep life exceeding 2000 hours by adding 0.02 or 0.04% by weight of lanthanum.

3 and 2 show creep lifespans according to the average energy level of d-orbital electrons of the nickel-based super-heat-resistant alloy prepared in Examples 1 to 7 and Comparative Examples 1 to 5.

3 and Table 2, it can be seen that the nickel-based super-heat-resistant alloys prepared by Examples 1 to 7 have a d-orbital electron average energy level in the range of 0.93 to 0.95, thereby improving creep life. On the other hand, the nickel-based super-heat-resistant alloy prepared in Comparative Examples 1 to 5 deviates from the d-orbital electron average energy level in the range of 0.93 to 0.95, and also creep life compared to the nickel-based super-heat-resistant alloy prepared in Examples 1 to 7 You can see this short.

Figure 4 shows the creep life according to the lanthanum weight% of the nickel-based super-heat-resistant alloy prepared in Example 4 and Example 5.

Referring to Figure 4, the creep life according to the lanthanum weight% of the nickel-based superheat-resistant alloy prepared in Examples 4 and 5 is the highest when the lanthanum is added by 0.02% by weight relative to the nickel-based superheat-resistant alloy Can be.

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited by the appended claims. Accordingly, various forms of substitution, modification, and modification will be possible by those skilled in the art without departing from the technical spirit of the present invention as set forth in the claims, and this also belongs to the scope of the present invention. something to do.

Claims (8)

17.0 to 21.0% by weight of chromium (Cr);
7.0 to 11.0% by weight of cobalt (Co);
5.0 to 9.5% by weight of molybdenum (Mo);
1.5 to 3.5% by weight of titanium (Ti);
0.8 to 2.5% by weight of aluminum (Al);
0.05 to 0.26% by weight of silicon (Si);
0.04 to 0.08% by weight of carbon (C);
0.0001 to 0.060% by weight of lanthanum (La);
0.003 to 0.007% by weight of boron (B);
Balance nickel (Ni);
And an unavoidable impurity; a nickel-based super-heat-resistant alloy for annealing having excellent creep characteristics.
delete According to claim 1,
The nickel-based super-heat-resistant alloy is a nickel-based super-heat-resistant alloy for annealing having excellent creep characteristics, further comprising 0.01 to 5.0% by weight of tungsten (W).
According to claim 1,
The nickel-based super-heat-resistant alloy is a nickel-based super-heat-resistant alloy for annealing, which has excellent creep characteristics, wherein the average energy level of d-orbital electrons is 0.93 to 0.95.
According to claim 1,
Nickel-based super-heat-resistant alloy for annealing with excellent creep characteristics with a creep life of 1500 to 2500 hours at a temperature of 760°C and a load of 283 Mpa.
17.0 to 21.0 wt% Chromium (Cr), 7.0 to 11.0 wt% Cobalt (Co), 5.0 to 9.5 wt% Molybdenum (Mo), 1.5 to 3.5 wt% Titanium (Ti), 0.8 to 2.5 wt% Aluminum (Al), 0.05 to 0.26 wt% silicon (Si), 0.04 to 0.08 wt% carbon (C), 0.0001 to 0.060 wt% lanthanum (La), 0.003 to 0.007 wt% boron (B) balance nickel (Ni) and unavoidable impurities, mixing and dissolving the raw material composed of;
Molding the mixed and dissolved alloy; And
Method of manufacturing a nickel-based super heat-resistant alloy for annealing excellent creep characteristics, including; heat-treating the molded alloy.
The method of claim 6,
The heat treatment of the molded alloy may include heat treatment of solution at 1100 to 1200°C; And a aging treatment at 700 to 850°C.
The method of claim 6,
The method of manufacturing the nickel-based super-heat-resistant alloy further includes a cooling step, and the cooling step is a method of manufacturing a nickel-based super-heat-resistant alloy for annealing having excellent creep characteristics performed at 1 to 40°C/s.

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