JP3209902B2 - High temperature corrosion resistant single crystal nickel-based superalloys - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to single crystal nickel-based superalloys and, more particularly, to bare hot corrosion for use in gas turbine engines.
osion) and a single-crystal nickel-based superalloy having improved resistance to the same and products made therefrom.

[0002]

BACKGROUND OF THE INVENTION Recent developments in temperature and stress performance of single crystal products have been the result of the continued development of single crystal superalloys and improvements in casting processes and engine applications. These single crystal superalloy products include rotating and stationary blades and vanes found in the hot sections of gas turbine engines. The goals of gas turbine engine design have remained the same for the past several decades. Such goals include higher engine operating temperatures, rotational speeds, fuel efficiency, and durability and reliability of engine components.

Prior art attempts to provide alloys to achieve these design goals for industrial gas turbine engine applications include U.S. Pat.
No. 4,677,035, which is, by weight percent, 8.0-14.0% chromium, 1.5-6.0% cobalt, 0.5%
~ 2.0% molybdenum, 3.0 to 10.0% tungsten, 2.
5-7.0% titanium, 2.5-7.0% aluminum, 3.
Disclosed is a nickel-based single crystal alloy composition consisting essentially of 0-6.0% tantalum and the balance nickel.
However, while the alloy compositions taught by this reference have relatively high strength when subjected to prolonged or repeated high temperatures, components machined from these alloys have been used in gas turbines. Susceptible to the accelerated corrosion effects of the sometimes exposed high temperature gas environment.

Further, British Patent No. 2153848 (2153848A)
Also without intentionally adding carbon, boron or zirconium, 13.0-15.6% chromium, 5-15% cobalt, 2.5
A nickel-based alloy having a composition in the range of 5% molybdenum, 3-6% tungsten, 4-6% titanium, 2-4% aluminum, and the balance nickel is disclosed, which comprises Processed into crystals. The alloys taught by this reference claim improvements in hot corrosion resistance with increased creep rupture properties, but improved hot corrosion resistance, oxidation resistance, mechanical strength, large part castability, and adequate There is a need in the art for single crystal superalloys for industrial gas turbine applications having an excellent combination of different heat treatment responses.

The dendritic gross pattern of the components
wth pattern) or blade stackin
g) Single crystal products are generally produced with a low modulus (001) crystallographic orientation parallel to the axis. Face-centered cubic (FCC) superalloy single crystals grown in the (001) direction provide significantly better thermal fatigue resistance than conventionally cast polycrystalline products. Because these single crystal products have no grain boundaries, alloy designs that do not use grain boundary strengtheners such as carbon, boron, and zirconium are possible. Because these elements lower the melting point of the alloy, by essentially removing them from the alloy design, they offer greater potential for achieving high mechanical strength.
Because a more complete gamma prime solution and microstructure homogenization is achieved compared to directional solidification (DS) columnar grains and conventionally cast materials, probably produced by higher initial melting points. This is because that.

[0006] The advantages of these processes are not necessarily realized unless a multi-faceted alloy design method is employed. Alloys, especially when used on large cast products, may have freckles, slivers,
s) must be designed to prevent the tendency of casting defects to form, such as spurious grains, and recrystallization. In addition, the alloy is treated with a suitable heat treatment "windo" to allow near complete gamma-prime solution.
w) "(numerical difference between the gamma-prime solvus of the alloy and the initial melting point). At the same time, the compositional balance of the alloy must be designed to provide the proper mix of engineering properties required for operation in a gas turbine engine. Selected properties that gas turbine engine designers generally consider important include high temperature creep rupture strength, thermo-mechanical fatigue resistance, impact resistance, resistance to hot corrosion and oxidation, and coating performance. In particular, industrial turbine designers demand a unique combination of resistance to hot corrosion and oxidation and good long-term mechanical properties.

[0007]

Alloy designers can attempt to improve one or two of these design characteristics by adjusting the compositional balance of known superalloys. However, it is extremely difficult to improve one or more of the design characteristics without significantly or significantly impairing some of the remaining characteristics. The unique superalloy of the present invention provides an excellent combination of properties required for use in the production of single crystal components that operate in the hot sections of industrial and marine gas turbine engines.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a high temperature corrosion resistant nickel-based superalloy comprising the following elements by weight: from about 14.2 to about 15.5% chromium, from about 2.0 to about 4.0. % Cobalt, about 0.30 to about 0.45% molybdenum, about 4.0 to about 5.0% tungsten, about 4.5 to about
About 5.8% tantalum, about 0.05 to about 0.25% niobium (columb
ium), about 3.2 to about 3.6% aluminum, about 4.0 to about 4.4%
Of titanium, about 0.01 to about 0.06% hafnium, and the balance of nickel and incidental impurities. This superalloy has a phasial stability nu of less than about 2.45.
mber) has _Nv3B .

Advantageously, the sum of aluminum and titanium in the superalloy composition is between 7.2 and 8.0% by weight. It is also advantageous for the composition of the present invention to have a Ti: Al ratio greater than 1 and a Ta: W ratio greater than 1. While the incidental impurities should be kept as low as possible, the superalloys of the present invention
About 0 to about 0.05% carbon, about 0 to about 0.03% boron, about 0 to about 0.05%
About 0.03% zirconium, about 0 to about 0.25% rhenium,
About 0 to about 0.10% silicon and about 0 to about 0.10% manganese can also be included. In all cases, the base element is nickel. The present invention provides a single crystal superalloy having improved resistance to high temperature corrosion, improved resistance to oxidation, and improved creep rupture strength.

[0010] Single crystal products can suitably be produced from the superalloys of the present invention. Such a product may be a component of a gas turbine engine, and more particularly, the component may be a gas turbine blade or gas turbine blade.

The superalloy compositions of the present invention have a critically balanced alloy composition, which results in a unique combination of desired properties, including improved resistance to high temperature corrosion. Superalloy compositions are particularly suitable for industrial and marine gas turbine applications. These properties include: excellent bare hot corrosion resistance and creep rupture strength; good bare oxidation resistance; good single crystal part castability, especially for large blade or blade parts; good solution heat treatment response; Appropriate resistance to part recrystallization; proper part applicability, and topological close packing (t
Includes microstructural stability, such as long-term resistance to the formation of undesirable brittle phases called opologically close-packed (TCP) phases.

Accordingly, one of the objects of the present invention is to provide a superalloy composition and a single crystal product made from said composition having a unique combination of desired properties including improved hot corrosion resistance. That is. It is another object of the present invention to provide a superalloy and a single crystal product made from the superalloy for use in industrial and marine gas turbine engines. These and other objects and advantages of the present invention will be apparent to those skilled in the art from the following description of preferred embodiments.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The hot corrosion resistant nickel-based superalloys of the present invention include, by weight percent, the following elements: chromium about 14.1 to 15.5 cobalt about 2.0 to 4.0 molybdenum about 0.30 to 0.45 tungsten about 4.0 to 5.0. Tantalum Approximately 4.5 to 5.8 Niobium Approximately 0.05 to 0.25 Aluminum Approximately 3.2 to 3.6 Titanium Approximately 4.0 to 4.4 Hafnium Approximately 0.01 to 0.06 Nickel and incidental impurities Residual amount

The superalloy composition also contains about 2.
It has a phase stability number N _v3B of 45 or less. Further, the present invention has a critically balanced alloy composition, which results in a unique combination of properties useful for industrial and marine gas turbine engine applications. These properties include a superior combination of bare hot corrosion resistance and creep rupture strength compared to prior art single crystal superalloys for industrial and marine gas turbine engine applications, bare oxidation resistance, single crystal Includes microstructural stability such as part castability and resistance to the formation of TCP phases under high stress, high temperature conditions.

The chromium content of the superalloy mainly contributes to obtaining the high-temperature corrosion resistance of the superalloy. The superalloys of the present invention have a relatively high chromium content because the hot corrosion resistance of the alloy was a major design criterion in the development of such alloys. The chromium content is about 14.2-15.5% by weight. Chromium content is 14.3 ~
Advantageously, it is 15.0% by weight. Chromium provides hot corrosion resistance, but can also help the alloy's oxidative tolerance. Further, the tantalum and titanium content of the superalloys of the present invention and their Ti: Al ratios greater than 1 contribute to achieving high temperature corrosion resistance. However, in addition to lowering the gamma prime solvus of the alloy, chromium also contributes to the formation of Cr and W-rich TCP phases, and therefore must be balanced in the compositions of the present invention.

In one embodiment of the present invention, the cobalt content is about 2.0-4.0% by weight. In another embodiment of the present invention, the cobalt content is about 2.5-3.5% by weight. The chromium and cobalt concentrations in these alloys help make the superalloy solution heat treatable, as both elements tend to lower the gamma prime solvus of the alloy. By properly balancing these elements in the present invention in conjunction with those that tend to raise the initial melting point of alloys such as tungsten and tantalum, the desired solution heat treatment window (initial melting point and its gamma prime solvus and (Numerical difference between the two) is obtained, thereby facilitating sufficient gamma prime solution.

Advantageously, the tungsten content is about 4.0-5.0% by weight and the amount of tungsten is about 4.2-4.8% by weight. Tungsten is added to these compositions because it is an effective solid solution enhancer and can contribute to the strengthening of gamma prime. In addition, tungsten is effective in raising the initial melting point of the alloy.

Like tungsten, tantalum is an important solid solution enhancer in the compositions of the present invention, but also contributes to improved gamma prime particle strength and volume fraction. The tantalum content is about 4.5-5.8% by weight;
Advantageously, the tantalum content is between about 4.8 and 5.4% by weight. In the compositions of the present invention, tantalum is used for bare hot corrosion and oxidation resistance and aluminide.
de) Advantageously because it helps to provide coating durability. In addition, tantalum, especially when present at a higher ratio than tungsten (i.e., when the Ta: W ratio is greater than 1), causes "freckl" during the single crystal casting process.
e) "It is an attractive single crystal alloy additive in the compositions of the present invention because it serves to prevent the formation of defects. In addition, tantalum is considered to not directly participate in the formation of the TCP phase, and is therefore an attractive means of obtaining strength in the compositions of the present invention.

The molybdenum content is about 0.30 to 0.45% by weight. Advantageously, molybdenum is present in an amount of 0.35 to 0.43% by weight. Although molybdenum is a good solid solution enhancer, it is not as effective as tungsten or tantalum and tends to be a negative factor for hot corrosion tolerance. However, since the density of the alloy is always considered in the design of the alloy, and molybdenum atoms are lighter than other solid solution strengtheners, the addition of molybdenum is a means of adjusting the overall density of the composition of the present invention. is there. The relatively low molybdenum content is believed to be unique in this class of bare hot corrosion resistant nickel-based single crystal superalloys.

The aluminum content is about 3.2-3.6% by weight. Furthermore, the amount of aluminum present in the composition according to the invention is advantageously between 3.3 and 3.5% by weight. Aluminum and titanium are the main elements constituting the gamma prime phase. In the present invention, the total of aluminum and titanium is 7.2 to 8.0% by weight. These elements are present in the compositions of this invention in the amounts and proportions necessary to achieve the appropriate alloy castability, solution heat treatability, phase stability, and desired combination of high mechanical strength and high temperature corrosion resistance. Is added. Also, aluminum is added to the alloy of the present invention in an amount sufficient to provide oxidation resistance.

The titanium content is about 4.0-4.4% by weight. In addition, titanium is present in the compositions of the present invention in 4.
Advantageously it is present in an amount of 1 to 4.3% by weight. The titanium content of the alloys of the present invention is relatively high, and is therefore advantageous for the hot corrosion resistance of the alloys. However, titanium can also have a negative effect on oxidation resistance, alloy castability, and the response of the alloy to solution heat treatment. Therefore, it is important that the titanium content be kept within the above-mentioned range of the composition of the present invention, and that the above-mentioned element components be properly balanced. Further, maintaining a Ti: Al ratio greater than 1 is important in achieving the desired bare hot corrosion resistance in the compositions of the present invention.

The niobium content is between about 0.05 and 0.25% by weight, advantageously the niobium content is between about 0.05 and 0.12% by weight. Niobium is a gamma prime forming element and is an effective enhancer in the nickel-based superalloys of the present invention. However, in general, niobium impairs the oxidation and hot corrosion resistance of the alloy, so that its addition to the compositions of the present invention is minimized. In addition, niobium is added to the composition of the present invention for the purpose of capturing carbon, which is chemisorbed to the surface of the components during a non-optimized vacuum solution heat treatment procedure. Carbon adsorbates tend to form niobium carbide instead of titanium carbide or tantalum, thereby retaining the maximum proportion of titanium and / or tantalum in the alloys of the present invention for gamma prime and / or solid solution strengthening. I do. Furthermore, in order to improve the strength of the superalloy of the present invention, it is important that the sum of niobium and hafnium is 0.06 to 0.31% by weight in the composition of the present invention.

The hafnium content is between about 0.01 and 0.06% by weight, and the hafnium is advantageously present in an amount between about 0.02 and 0.05% by weight. Hafnium is added to the compositions of the present invention in low proportions to aid coating performance and adhesion. Hafnium generally splits the gamma prime phase.

The balance of the superalloy composition of the present invention consists of nickel and small amounts of incidental impurities. Generally, these ancillary impurities are introduced from the industrial process of manufacture, but must be kept as small as possible in the composition so as not to adversely affect the advantageous aspects of the superalloys of the present invention. For example, these incidental impurities
Up to about 0.05% carbon, up to about 0.03% boron, up to about 0.03% zirconium, up to about 0.25% rhenium, about 0.10%
Up to about 0.10% silicon and up to about 0.10% manganese. The amounts of these impurities in excess of the amounts described above can adversely affect the properties of the resulting alloy.

The superalloys of the present invention not only have a composition within the range described above, having a phase stability number N _V3B below about 2.45 or less. As will be appreciated by those skilled in the art, N
_v3B is a nickel-based alloy vacancy TCP phase control element calculation (nickel-based alloy _ellipse).
electron vacancy TCP phasec
control factor calculatio
n) defined by the PWA N-35 method. This calculation is as follows.

Conversion of Formula 1 Weight Percent to Atomic Percent: Atomic% of Element i = Pi = (Wi / Ai) / (Σi (Wi / Ai)) × 100 where: Wi = weight% of element i Ai = Atomic weight of element i.

The amount of each element present in two consecutive matrix phase calculator: element amount of remaining atoms _{Rii Cr R Cr = 0.97P Cr -0.375P} B -1.75P C Ni R Ni = P Ni +0. 525P _B -3 (P _Al +0.03 P _Cr + P _Ti -0.5P _C +0.5 P _V + P _Ta + P _Cb + P _Hf ) Ti, Al, B, Ri = 0 C, Ta, Cb (niobium), Hf V R _{V = 0.5P V W R W = P} W -0.167P C P W / (P Mo + P W) Mo R (Mo) = P (Mo) -0.75P B -0.167P C P Mo / (P Mo + P W)

Equation 3 Calculation of N _v38 using the atomic factors obtained from Equations 1 and 2 above: N _i ⁱ = R _i / _i R _i where N _v3B = Σ _i Ni (N _v ) i where: i = sequential individual elements, N _i i = atomic factor of each element in matrix, (N _v ) i = electron vacancy number of each individual element.

This calculation is based on the International Symposium on Structural Stability in Superalloys.
on Structural Stability in Superalloys)
968), HJ Murphy, CT Sims,
And in the technical literature entitled "PHACOMP Revised" by AM Beltran.
The disclosure of which is incorporated herein by reference. As will be appreciated by those skilled in the art, the phase stability number is important for the superalloys of the present invention, and to provide a stable microstructure and tolerance for desired properties under high temperature and high stress conditions, the maximum Must be: Those skilled in the art, once having understood the contents of the present specification, can determine the phase stability number experimentally.

The superalloy of the present invention can be used to suitably manufacture single crystal components, such as industrial and marine gas turbine engines. These superalloys are preferably used to produce single crystal castings used under high stress, high temperature conditions, and such castings are particularly suitable for corrosive environments containing sulfur, sodium and vanadium impurities. It is characterized by having improved hot corrosion (sulfide) resistance under conditions such as high temperatures up to about 1050 ° C (1922 ° F). While these superalloys can be used for any purpose that requires high-strength castings manufactured as single crystals, their special use is in the manufacture of single crystal blades and blades for industrial and marine gas turbine engines. Casting.

[0031] Single crystal parts made from the compositions of the present invention can be made using any single crystal casting technique known in the art. For example, seed crystal
Single crystal directional solidification processes such as the process and the choke process can be used.

[0032] Castings made from the superalloys of the present invention can be aged at a temperature of about 982 ° C (1800 ° F) to about 1163 ° C (2125 ° F) for about 1 to about 50 hours. However, as will be appreciated by those skilled in the art, the optimal temperature and time for aging will depend on the exact composition of the superalloy.

The present invention provides superalloy compositions having a unique combination of desired properties. These properties include excellent bare hot corrosion resistance and creep rupture strength; good oxidation resistance; good single crystal part castability, especially for large blade or blade parts; good solution heat treatment response;
Appropriate resistance to recrystallization of cast parts; proper part coatability and microstructural stability, such as long-term resistance to the formation of undesirable brittle phases called topological close-packed (TCP) phases. . As noted above, this superalloy has a precise composition that allows only small variations for all elements if a unique combination of properties must be maintained.

The following examples are provided to more clearly illustrate the present invention and to show comparisons with representative superalloys outside the scope of the present invention. The following example,
It is intended to show the invention and the relationship between the invention and other superalloys and products and does not limit the scope of the invention.

[0035]

EXAMPLES Test materials were prepared to examine compositional variability and range for the superalloys of the present invention. One of the alloy compositions that were tested and reported below is outside the scope of the present invention, but was included for comparison to aid in understanding the present invention. Table 1 below shows typical alloy target compositions of the tested materials.

[0036]

[Table 1]

CMSX®-11C shown in Table 1
6.8039 kg of test material defined by the target composition of
(15 pounds) R2D2 alloy melt (see Table 2 below)
And 3.6287 kg (8 pounds) of new elements were mixed, melted, and initially produced by pouring the melt into a ceramic shell mold. (CMSX is a registered trademark of Canon-Maski-Gun Corporation, the assignee of the present application.)

Using the resulting blended product, nineteen 9/8 in. (3/8 inch) diameters and 15.24 cm (6 in.)
A length of test rod and three solid turbine blades were investment cast. Examination of the sample showed that it had a satisfactory grain yield and that only one test rod was rejected for mis-orientation. No freckles appeared. Furthermore, the chemical composition of the test rod was inspected.
It was shown that the target composition of 11C was obtained.

Still another test material was obtained using an alloy product, VIM, manufactured in an amount of 250-270 pounds. The VIM melts produced and their respective compositions are shown in Table 2 below.

[0040]

[Table 2]

Small amounts of these materials were remelted and precision investment cast into both bars and blades.

Inspection of the particles and orientation on the investment cast product has given satisfactory results. In general, the target compositions reported in Table 1 above yielded the products shown in Table 2 and were single crystals and spurious grai
n) and / or no signs of sliver, no apparent freckles, desired primary (001)
SX cast parts were produced having directions generally within 10 ° of the crystallographic direction and meeting compositional requirements.

Using some of the test samples produced, a suitable solution heat treatment method was developed. The results are shown in Table 3 below. Completely coarse γ 'and eutectic γ-γ' solution solution at 1265 ° C
Achieved by applying a peak solution temperature of (2309 ° F).
However, various levels of recrystallization of the test sample were observed during the solution heat treatment. The problem is CMSX-11
It was alleviated by lowering the peak solution temperature of the C alloy to 1254 ° C. (2289 ° F.), where complete γ ′ solution was still dominant.

Similarly, the other two compositional variants listed in Table 1 (CMSX-11C 'and CMSX-11
C ″) was solution treated to a peak temperature of 1254 ° C. (2289 ° F.) with similar results.

All test samples were initially run at 1121 ° C. (20
Aged at 50 ° F. to promote the desired γ ′ morphology and distribution, followed by heat treatment by second aging at 871 ° C. (1600 ° F.) and 760 ° C. (1400 ° F.), respectively. (See Table 3 below).

[0046]

[Table 3]

Differential thermal analysis (DTA) of the VIM melt (shown in Table 2 above) gave the solidus and liquidus data for each alloy. Details of the DTA are shown in Table 4 below.

[0048]

[Table 4]

Following the heat treatment, the test rod was machined to a standard ASTM standard sample size and subjected to stress and creep rupture tests under various temperature and stress conditions according to the standard ASTM method. Stress polished. Samples taken from solid turbine blades were similarly manufactured.

Table 5 reported below shows CMSX-11C
The results of a stress rupture test and a creep rupture test performed on an alloy sample are shown. These tests range from 760 to 1038 ° C (1
400-1900 ° F).

Most of the tests reported in Table 5
Performed on an alloy from the previously described melt R2D2 / new material blended with the product from melt VF998. Test results for materials made using the melt VG33 product are marked in Table 5. The products from the remaining VIM melts shown in Table 2 were not tested for breakage.

[0052]

[Table 5]

[0053]

[Table 6]

[0054]

[Table 7]

Selected rupture test samples were metallographically observed after the test. None of the observed fractured samples had undesirable microstructural instability, i.e., sigma,
Topolog dense, such as mu or other
There was no observable sign of the formation of an ically-Close-Packed (TCP) phase.

Further, two test bars were set at 870 ° C./270 MPa.
(1600 ° F / 39.2 ksi) for 200 hours. Observation of the gage section of each bar showed no signs of harmful phase formation.

[0057] Low Cycle Fatigue
The results of the (LCF) test are shown in Table 6 below. 600 ° C (111
The results of the strain control test performed at 2 ° F. were compared with the single crystal CMS
It compares the typical capabilities of X-2 alloy, DS, and other selected alloys such as the equiaxed CM 247 LC® alloy and DS Rene 80H alloy.

[0058]

[Table 8]

In parallel with the above evaluation, the fully heat treated CMSX-11C test sample was subjected to a bare oxidation and high temperature corrosion test.

The results of the high temperature corrosion tests performed are reported in Table 7 below. This test was performed at 700 ° C. (1292 °) in a laboratory furnace using artificial ash and SO ₂ .
F) and 800 ° C. (1472 ° F.). The metal loss data reports the average and maximum values as well as the percentage of test pin loss used. Data are reported at 100, 576, and 1056 hour intervals for the 700 ° C (1292 ° F) test and 100, 576, 105 for the 800 ° C (1472 ° F) test.
Data were reported at intervals of 6 and 5000 hours.

[0061]

[Table 9]

Similarly, FIG. 1 shows that the CMSX-11C alloy and other alloys are synthesized in a slug (GTV type) and in air.
The results of additional hot corrosion tests performed by exposing 500 hours 03 vol% of SO _x. This 500-hour exam is 7
Performed at 50, 850, and 900 ° C (1382, 1562, and 1652 ° F). These results indicate that the CMSX-11C alloy provides very good corrosion resistance at all three temperatures.

Other tests using another slug, type FVV, at test temperatures of 800 ° C. and 900 ° C. (1472 ° F. and 1652 ° F.) were also performed. The results of the 500 hour test are reported in Table 8 below. These results show that the CMSX-11C alloy with higher chromium content is superior in performance compared to the CMSX-11B alloy with 12.5% chromium content.

[0064]

[Table 10]

An additional experimental furnace (crucible type) artificial ash hot corrosion test was performed. 732 ° C (1350 ° F) and 899 ° C (1650 °
The results of these tests performed in F) are shown in FIGS. 2 and 3, respectively. In these tests, one every 100 cycles
The samples were coated with mg / cm ² Na ₂ SO ₄ and cycled three times per day. Each test was performed for about 2400 hours. These results show that the level of hot corrosion resistance obtained with the CMSX-11C alloy is further improved compared to the CMSX-11B material.

Further, a high temperature corrosion test was performed on the CMSX-11C alloy together with other alloys for comparison purposes. In contrast to the tests described above, these hot corrosion assessments were performed in burner rigs. This is usually the preferred test method. This is because the results obtained in burner drilling tests generally provide a more typical indication of how the material will function in a gas turbine engine.

The burner excavation test was conducted at 900 ° C (1652 ° F) and 1
Performed at 050 ° C (1922 ° F). The test results are shown in Tables 9 and 10 below, respectively. Diameter 9 mm (0.35 inch) x length 1
A 00 mm (3.9 inch) test pin was mounted on a rotating cylindrical jig and exposed to a high velocity gas flow. Other test conditions are specified in each table.

[0068]

[Table 11]

[0069]

[Table 12]

The test results show that at both test temperatures C
The MSX-11C alloy provides much better hot corrosion resistance than the IN 738LC alloy, and furthermore the CMSX-11B
It shows that it has better performance than the alloy. Further, FIG. 4 shows that CMSX-11C alloy is 1050 ° C. (1922 ° F.).
To provide a preferred combination of strength and high temperature corrosiveness, and in particular, the commercially widely used DSR
It shows that the performance is superior to the ene 80 H alloy. It is believed that a similar analysis at 900 ° C. indicates a better combination of capabilities.

In parallel with the high temperature corrosion test, CMSX-11
An oxidation test of the C alloy was performed. Table 11 below shows the
Crucible oxidation test performed at 950 ° C (1742 ° F) for 1000 hours (cr
ucible oxidation test). The average and maximum oxidation depth and weight gain measured at intervals of 100 and 500 hours and at the end of the test are reported.

[0072]

[Table 13]

FIG. 5 shows the results of the oxidation test at a slightly higher temperature. The data shown is 30 ° C at 1000 ° C (1832 ° F).
It is a result of an oxidation test performed up to 00 hours. The test was performed in air and the change in weight of the test sample was measured as a function of time. The test temperature was cycled to room temperature on an hourly basis. Test results indicate that the CMSX-11C alloy provides much better oxidation resistance than IN 738LC, an alloy widely used in the industrial turbine industry.

FIG. 6 shows the results of the oxidation test. In this particular test, the pins were kept at 1010 ° C (1850 ° C).
° F) from the test temperature to room temperature three times a day,
Weight change was measured as a function of time. The test was performed for about 2400 hours. The result is that CMSX-11C material is alloy IN
It shows much better oxidation resistance than 738 LC.

The burner excavation oxidation test was performed at 1200 ° C. (2192 °
F). The results are shown in Table 12 below. Various alloys were tested in the same rotating circular platform. Sample weight loss was measured at intervals of 100, 200, 300, 400, and 500 hours. Other test conditions are given in the table.

[0076]

[Table 14]

The result of the burner excavation oxidation test was CMSX
-11C material has a very good 1200 ° C. compared to widely used industrial turbine blade and blade materials
(2192 ° F.).

A comparison between the strength of the alloy and 1200 ° C. (2192 ° F.) oxidation is shown in FIG. This figure shows CMSX-11C
The combined ability of the alloys is Rene 80 H, F
It shows superiority to directionally solidified alloys such as SX414, IN 939 and IN 738 LC alloys.

Although the invention has been described with reference to specific embodiments, many other forms and modifications of the invention will be apparent to those skilled in the art. It is intended that the following claims and the invention be interpreted as covering such obvious forms and modifications as fall within the true spirit and scope of the invention.

[Brief description of the drawings]

FIG. 1 is a graph showing the results of a high temperature corrosion test performed on one embodiment of the present invention and four other alloys at three exposure temperatures.

FIG. 2 is a graph showing a comparison of hot corrosion data from tests performed at 1350 ° F. for one embodiment of the present invention and two other alloys.

FIG. 3 is a graph showing a comparison of hot corrosion data from tests performed at 1650 ° F. for one embodiment of the present invention and two other alloys.

FIG. 4 is a graph showing a comparison of alloy strength and hot corrosion data from tests performed on one embodiment of the present invention and six other alloys.

FIG. 5 is a graph showing a comparison of oxidation data obtained from tests performed at 1000 ° C. (1832 ° F.) for one embodiment of the present invention and two other alloys.

FIG. 6 is a graph showing a comparison of oxidation data obtained from tests performed at 1010 ° C. (1850 ° F.) for one embodiment of the present invention and two other alloys.

FIG. 7 is a graph showing a comparison of alloy strength and oxidation data obtained from tests performed on one embodiment of the present invention and six other alloys.

Continuation of the front page (56) References JP-A-7-145703 (JP, A) JP-A-4-280938 (JP, A) JP-A-4-124237 (JP, A) JP-A-3-291333 (JP) JP-A-62-235450 (JP, A) JP-A-62-30037 (JP, A) JP-A-57-210942 (JP, A) JP-B-63-43458 (JP, B2) JP-B-sho 62-3221 (JP, B2) JP 5-69891 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C22C 19/05 C30B 29/52

Claims (20)

(57) [Claims] Claims 1. A high temperature corrosion resistant nickel-based superalloy comprising, by weight percent, chromium 14.2 to 15.5 cobalt 2.0 to 4.0 molybdenum 0.30 to 0.45 tungsten 4.0 to 5.0 tantalum 4.5 to 5.8 niobium 0.05 to 0.25 aluminum 3.2 to 3.6 titanium 4.0 to 4.4 hafnium 0.01 to 0.06 nickel and incidental impurities remaining amount includes an element, superalloy having 2.45 or less of phase stability number N _V3B. Wherein in weight percent, carbon from 0 to 0.05 further comprises a boron 0 to 0.03 zirconium 0 to 0.03 rhenium 0 to 0.25 silicon 0 to 0.10 manganese from 0 to 0.10, superalloy of claim 1. 3. The total of niobium and hafnium is 0.06 to 0.31.
2. The superalloy of claim 1 which is in weight percent. 4. The ratio of Ti to Al (Ti / Al)
The superalloy of claim 1, wherein is greater than one. 5. The total of aluminum and titanium is 7.2
2. The superalloy of claim 1 wherein the amount is about 8.0% by weight. 6. The ratio of Ta to W (Ta / W) is 1
The superalloy of claim 1, wherein the superalloy is greater. 7. The superalloy of claim 1 having improved oxidation resistance. 8. A single crystal product made from the superalloy of claim 1. 9. The product of claim 8, which is a component for a turbine engine. 10. The product of claim 9, which is a gas turbine blade or gas turbine blade. 11. A single crystal casting having excellent resistance to high temperature corrosion, comprising, in weight percent, chromium 14.3-15.0 cobalt 2.5-3.5 molybdenum 0.35-0.43 tungsten 4.2-4.8 tantalum 4.8-5.4 niobium 0.05- 0.12 Aluminum 3.3-3.5 Titanium 4.1-4.3 Hafnium _0.02-0.05 A single crystal casting made from a nickel-based superalloy containing nickel and ancillary impurities with a balance of _Nv3B of 2.45 or less. 12. The single crystal casting of claim 11, wherein the superalloy further comprises, by weight percent, carbon 0-0.05 boron 0-0.03 zirconium 0-0.03 rhenium 0-0.25 silicon 0-0.10 manganese 0-0.10. 13. The total of niobium and hafnium is 0.06 to 0.
The single crystal casting of claim 11, which is 31% by weight. 14. The total of aluminum and titanium is 7.
The single crystal casting according to claim 11, which is 2 to 8.0% by weight. 15. The ratio of Ti to Al (Ti / A)
The single crystal casting of claim 11, wherein the ratio of Ta to l) and W (Ta / W) is greater than one. 16. The single crystal casting of claim 11 having improved oxidation resistance. 17. The single crystal casting of claim 11, having improved creep rupture strength. 18. The single crystal casting according to claim 11, which is a gas turbine blade or a gas turbine blade. 19. A single crystal casting having excellent resistance to hot corrosion, in weight percent, chromium 14.5 Cobalt 3.0 Molybdenum 0.40 Tungsten 4.4 Tantalum 4.95 Niobium 0.10 Aluminum 3.40 Titanium 4.2 Hafnium 0.04 Carbon 0 to 0.05 boron from 0 to 0.03 zirconium 0 to 0.03 rhenium 0 to 0.25 silicon 0 to 0.10 manganese from 0 to 0.10 nickel remainder amount, a single crystal castings made from a nickel-based superalloy containing an element, the superalloys is 2.45 or less phase It has a stability number N _v3B and the sum of niobium and hafnium is
0.06-0.31% by weight, the sum of aluminum and titanium is 7.2-8.0% by weight, and the ratio of Ti to Al
(Ti / Al) is greater than 1 and Ta to W
Is a single crystal casting having a ratio (Ta / W) of greater than 1. 20. The single crystal casting according to claim 19, which is a gas turbine blade or a gas turbine blade.