JP3474634B2 - Polycrystalline nickel superalloy and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a nickel superalloy, and a method for manufacturing a nickel superalloy having high oxidation resistance by containing a predetermined amount of boron and zirconium. Such nickel superalloys is suitable for technical fields has excellent oxidation resistance and high strength at high temperatures is required, for example, of a jet engine combustor, are suitable for the nozzle, and a low turbine constituting material and the like.

[0002]

2. Description of the Prior Art Various nickel-based superalloys have been known. A superalloy is an alloy that maintains high strength even at high temperatures. Nickel-based superalloys have been described, for example, in U.S. Patent Nos. 3,322,543 and 3,526,4.
No. 99, 3,653,987, 3,832,167, and 4,719,080, the contents of which are described later.

Other commercially available nickel-based superalloys include B1900 + Hf and Mar-M247. The composition of the components is shown below by weight ratio (wt%).

[0004]

Table 3 B1900 + HF Mar-M247 nickel balance balance balance 8.0 8.0 8.4 cobalt 10.0 10.0 10.0 carbon 0.11 0.15 titanium 1.0 1.1 aluminium 6.0 5.5 molybdenum 6. 0 0.65 Tungsten-10.0 Boron 0.015 0.015 Hafnium 1.15 1.4 Tantalum 4.25 3.1 Zirconium 0.08 0.055 These alloys maintain high mechanical strength even at high temperatures. Therefore, it is particularly useful as a material for forming a jet engine.

In order to improve the boundary strength and the ductility of the particles of the superalloy, boron is usually used in the conventional method in an amount of 0.010 to 0.020 wt.
% Added.

Further, in order to improve the boundary characteristics of particles,
Zirconium is usually added in an amount of 0.03 to 0.13 wt%. Yttrium may be added to increase the oxidation resistance of the nickel superalloy.

[0007]

However, in the prior art, nickel superalloys, which are said to provide excellent oxidation resistance at high temperatures [above about 1093 ° C. (2000 ° F.)], are very brittle.

[0008] Thus, with good ductility can be obtained, it has become necessary nickel superalloy having excellent oxidation resistance at high temperatures.

Also, about 760 to 1038 (° C) (1400 °
F~1900 ° F) turbine construction material of a jet engine with good strength and excellent oxidation resistance in a temperature range of is also required.

[0010] The present invention has been made based on the above background, have excellent oxidation resistance at high temperatures, also aims to provide a nickel-base superalloy having good ductility (nickel superalloy) And

Further, about 760 to 1038 (° C.) (1900 ° F.
Good strength is maintained in the temperature range of ~ 1400 ° F),
An object of the present invention is to provide a nickel superalloy suitable as a constituent material of a jet engine.

[0012]

In order to solve the above problems, the present invention provides 0.004 to 0.010 wt% boron and 0.25 to 0.40.
It is characterized by containing wt% zirconium.

A method for producing a polycrystalline nickel superalloy having high oxidation resistance , comprising the step of incorporating 0.25 to 0.40 wt% zirconium and 0.004 to 0.010 wt% boron in the superalloy. A method of making the featured superalloy is also provided.

[0014]

In the preferred embodiment, the superalloys of the present invention contain 5.0 to 8.0 wt% aluminum to create a barrier layer which provides the effect of inhibiting superalloy oxidation.

The presence of zirconium in the superalloy promotes the formation of an alumina barrier layer.

[0016] by burner rig oxidation testing, boron was revealed that adversely affect the oxidation resistance at high temperature [about 1,093 to 1,204 ° C. (from 2,000 to 2,200 ° F)].

Although the removal of boron from the nickel superalloy does not present such problems, it results in an unacceptably poor ductility of the alloy.

By adding a small amount of boron (0.020-0.010 wt%), the oxidizing effect was acceptable, but its ductility was insignificant under optimal conditions.

Further, the addition of yttrium causes a problem of weakening due to the formation of surface oxide fine particles during casting. This is a problem that results from the reaction of yttrium with the cast ceramic.

However, as a result of further experiments, the combination of zirconium and boron at the levels indicated in the present specification maintains the boundary properties of the particles and thus the inclusion formation during casting. It has been found that it is possible to suppress and at the same time make the oxidation resistance of nickel superalloys cast by conventional methods very high.

In addition to the above critical concentrations of zirconium and boron, it is recognized that the nickel superalloy according to the present invention exerts its effect when each element is added in the following weight ratio.

[0022]

[Table 4] Element Weight ratio (wt%) Chromium 5.0 to 12.0 Hafnium 0.75 to 2.0 Cobalt 0 to 1.0 The following elements are added to enhance the strength of the alloy.

[0023]

[Table 5] Element weight ratio (wt%) Tungsten 0-12 Molybdenum 0-12 Tantalum 0-12 Titanium 0-2 Columbium (niobium) 0-2 Carbon 0.06-0.20 Manganese, phosphorus, sulfur, silicon, iron, bismuth, The elements of lead, selenium, tellurium, and thallium are added at low levels in order to suppress the deterioration of the characteristics of the superalloy.

In another embodiment of the invention, the superalloy contains the elements given in the following weight ratios:

[0025]

[Table 6] Nickel Remainder If desired, the superalloy according to the present invention may contain the following additives. The maximum addition weight ratio (wt%) is also shown below.

Manganese (0.20), phosphorus (0.015), sulfur (0.015), silicon (0.10), iron (0.25), titanium (0.10), columbium (0.10), bismuth (0.0000)
5, 0.5ppm), lead (0.0002, 2ppm), selenium (0.000)
1, 1ppm), tellurium (0.00005, 0.5ppm), and thallium (0.00005, 0.5ppm).

[0027] Thus, according to the present invention, equiaxed nickel superalloy having excellent oxidation resistance under conditions such as occur in the jet engine is shown. 0 for this superalloy.
It contains 25 to 0.40 wt% zirconium and 0.004 to 0.010 wt% boron. Under burner rig oxidation conditions, a zirconium-stabilized alumina barrier layer is formed in this alloy that significantly reduces the oxidation rate of the alloy.

A method for producing the above superalloy and a method for casting an engine constituent material using the superalloy as a raw material are also shown.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an illustration of burner rig oxidation results at about 1093 ° C. (2000 ° F.), which shows nickel superalloys according to the present invention and other commercially available nickel superalloys (B1900 + Hf, MAR M-.
247) and weight loss over time. The constituent components of these alloys are shown in Table 3.

FIG. 2 is an illustration of burner rig oxidation result times at about 1204 ° C. (2200 ° F.), comparing the nickel superalloy of the present invention with other commercially available nickel superalloys in weight loss over time. Is.

In accordance with the present invention, the resulting alloy is an ingot of the required composition, vacuum remelted, and a precision-baked alloy used to obtain an alloy containing nickel as the major component by conventional methods. It is obtained by performing recasting using a casting method. The ingot is cast by a single furnace charge under vacuum.

The flow baked superalloy in the conventional method precision casting, as formed Engineering ingot superalloys, and SuperalloysII (Sims et respect to other general information, John Wiley & son
S., New York, 1987), the contents of which are referred to below.

[0034] Typically, the industrial, master heat (master he element to be alloyed at the time of degree ingot formation of Engineering
at). In a preferred embodiment, Mn, P, S, Si, Fe, Ti, Cb (Nb), Bi, Pb, Se, T in alloy elements
The added amount of e, Tl, etc. is smaller than the maximum value of each content described above.

Table 7 shows an example of the component composition of the above alloy.

[0036]

[Table 7]

In one example of the present invention, a superalloy having the composition shown in Table 7 was obtained. It should be noted that this example does not limit the present invention.

A nickel superalloy having a composition similar to that of the present invention but having a boron and zirconium content not within the critical range specified in the present invention was compared with the superalloy according to the present invention. As shown in Table 8, excellent ductility was exhibited in the present invention.

[0039]

[Table 8] Tensile elongation (%) Alloy 24 ° C (75 ° F) 649 ° C (1200 ° F) 871 ° C (1600 ° F) 982 ° C (1800 ° F) Invention 6.0 5.3 6.6 7.0 Alloy 1 1.3 0.7 3.3 2.0 The tensile extension test referred to is the Metals handbook (No. 9).
Edition, American Society for Metals vol 8, 1985).

The tensile elongation properties in the superalloys of the invention were tested according to the guidelines set out in ASTM E8.

In one embodiment, a superalloy according to the present invention was tested at three ASTM E 8 tests at 649 ° C (1200 ° F).
An average tensile elongation of greater than 0% was obtained.

In the preferred embodiment, the superalloys of this invention are tested at three ASTM E8 at 1200 ° F (649 ° C).
An average tensile elongation of more than 5.0% was obtained.

By the burner rig oxidation test, the superalloy of the present invention was found to be conventional nickel superalloy B1900 + HF, Mar-M-24.
It was shown to have excellent oxidation resistance as compared with 7 (see FIGS. 1 and 2 and Table 7).

The burner rig test at 1204 ° C. (2200 ° F.) was repeated 70 times, and it was 55 for B1900 + HF.
%, Mar-M-247 had a weight loss of 75%, whereas the alloy of the present invention had a weight loss of only about 2%.

In the burner rig repeat test used to evaluate the superalloys of the present invention, the liquid fuel burner was controlled by the fuel pressure to maintain the temperature of interest.

When the test is repeated, the sample is taken out or the flame is extinguished, and the sample is cooled by direct exposure to the high pressure atmosphere.

The sample is usually in the form of a cylindrical rod [0.47 inch diameter x 3.25 inch length (0.47 "x 3.25") in this example]. The samples can also be tested individually. A rotating spindle is used to test multiple samples.

In order to monitor the material loss due to oxidative peeling, the weight and diameter of the sample are measured at regular intervals during the above test. The oxidation rate is proportional to the weight loss (the oxidation ratio increases as the mass loss increases).

[0049] To characterize the nickel superalloy of the present invention, it is also possible to carry out the second oxidation resistance test.

In this test method, a superalloy coupon
Coupons are hung from wires and placed in a furnace maintained at 1149 ° C ± 14 ° C (2100 ° F ± 25 ° F) exposed to the atmosphere.

In this test method, the shape of the alloy sample is 12.7 ±
3.05 (mm) × 19.05 ± 3.05 (mm) Square and height 1.016 ± 0.254 (mm)
[0.50 × 0.75 in. ± 0.12 in. By 0.040 in. ± 0.010 in.]

Prior to inserting the sample, each side and apex of the sample is rounded.

The sample is heated in a cycle of 24 ± 4 hours.
At the end of each cycle, the sample is removed from the furnace and weighed after cooling in air. The mass exfoliated during heating or cooling is not measured.

[0054] As the oxidation resistance test examples of the alloy according to the present invention, in the air, 1149 ° C. (2100 ° F) at 300 hours Weight Loss repeated test results conducted, the amount of loss, 10 of the original weight It did not exceed%.

Acid resistance of alloys according to preferred embodiments of the present invention
As resistance test example, in the atmosphere, 1149 ° C. at a repetition conditions (2
A weight loss test was conducted at 100 ° F for 300 hours. As a result, the amount of loss did not exceed 5% of the original weight.

[0056] 30 to super alloy sample according to the present invention the greater the Engineering
When applied for 2 hours (11 cycles), its weight loss was 4.7%.

The superalloys included in the present invention were also prepared. The composition of the components is shown in Table 9 below. Note that these do not limit the present invention.

[0058]

[Table 9]

In a preferred embodiment, the nickel superalloy component according to the present invention is 1079 ± 14 ° C. (1975 ± 25 ° C.) in air.
F) for 4 hours, at least 22 ° C / min (40 ° F / min)
It was air cooled.

This component was then 871 ± 14 ° C. (1600 ± 2
Heated at 5 ° F for 16 hours and at least 22 ° C / min (40 °
It is air cooled at F / min). This heat treatment improves the ductility and creep properties of the superalloy component.

In a preferred embodiment, the polycrystalline nickel superalloy according to the present invention is equiaxed, and in another embodiment, the polycrystalline nickel superalloy according to the present invention is columnar. )Met.

The nickel superalloy constituents of the present invention shown in Table 7 could be suitably used as constituents of a float wall combustor.

Although the present invention has been described with reference to various preferred embodiments, it is possible to use the preferred embodiments without departing from the spirit and scope of the present invention.
It goes without saying that various modifications and variations that can be easily devised by those skilled in the art are possible. Such modifications and variations are intended to fall within the scope of the invention and the appended claims.

[0064]

According to the alloy of the present invention, about 1093 ° C (2000
° F), preferably excellent oxidation resistance at up to about 1204 ° C. (2200 ° F) is obtained. The nickel superalloy of the present invention has a
Good strength was obtained in the temperature range of 760 ° C (1400 ° F) to about 1038 ° C (1900 ° F).

[0065] Since the superalloy of the present invention has excellent oxidation resistance, the jet engine combustor, such as a nozzle and low turbine construction materials, also suitable for high temperature applications.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of burner rig oxidation results at about 1093 ° C. (2000 ° F.).

FIG. 2 is an explanatory diagram of burner rig oxidation result time at about 1204 ° C. (2200 ° F.).

Continuation of front page (72) Inventor Paul P. Norris, Jr. USA, Florida, Junoeach, APT. 9, Mercury Circle 250 (56) Reference JP-A-61-79742 (JP, A) JP-B 5-69891 (JP, B2) JP-B 47-15585 (JP, B1) JP-B 36-11111 (JP, B1) JP-B 35-11909 (JP, B1) JP-B 56-31345 (JP, B1) JP-B 38-4160 (JP, B1) JP-B 43-12505 (JP-B1) Publication 36-13511 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C22C 1/00-49/14 B22C 9/04

Claims (13)

(57) [Claims] 1. A 0.25~0. 35 wt% of zirconium, 0.004
～0.010Wt% boron, 6.5 0 to 6.7 0 wt% of aluminum, of 9.5 to 1 0.5 0 wt% chromium, 1. 0 5~ 1. 25 wt% of hafnium, 3.00 ~ 3.40 wt% tungsten, 1.75 to 2. 25 wt%
Molybdenum, 3.9 0 to 4.30 wt% tantalum, and 0.0 8
~0. 13 wt% of carbon, containing, polycrystalline nickel-based superalloy, wherein the balance nickel. 2. The alloy of claim 1, wherein the particles of the alloy are equiaxed. 3. The alloy according to claim 1, wherein the particles of the alloy are columnar. 4. An alumina layer which suppresses the oxidation of the superalloy is formed on the surface of the superalloy when exposed to an oxidizing condition at a temperature of 1093 ° C. or higher . The alloy according to any one. 5. The alloy according to any one of claims 1 to 4 , wherein the alloy contains 0.007 wt% or less of boron. 6. The nickel-base superalloy having an average tensile elongation of 3% in three ASTM E 8 tests at 649 ° C. of 12.7 ± 3.05 (mm) × 19.05 ±
The original weight loss sample in the atmosphere of 1149 ° C. at a cycle of 24 ± 4 hours for 300 hours in the atmosphere using the above superalloy sample having a shape of 3.05 (mm) square and a height of 1.016 ± 0.254 (mm). It is less than 10% of the weight of.
The alloy according to any one of to 5 . 7. The average tensile elongation in three ASTM E 8 tests at 649 ° C. exceeds 5.0% and is 12.7 ± 3.0.
Using the above superalloy sample having a shape of 5 mm × 19.05 ± 3.05 (mm) and a height of 1.016 ± 0.254 (mm), in air, 1149
° C., the alloy according to any one of claims 1 to 6, wherein the weight loss in the test of 300 hours in cycles of 24 ± 4 hours is not more than 5% of the weight of the original sample. 8. A jet engine construction material characterized by containing a nickel-base superalloy according to any one of claims 1-7. Wherein said structure material, combustor or construction material according to claim 8, wherein the a nozzle or low turbine constituting material. 10. A method for producing oxidation resistant polycrystalline nickel superalloy, 0.25~0. 35 wt% of zirconium, 0.004～0.010Wt% boron, 6.5 0 to 6.7 0 wt% aluminum, 9.5 to 1 0.5 0 wt%
Of chromium, 1. 0 5~ 1. 25 wt% of hafnium, 3.00 ~ 3.40 wt
% Tungsten, 1.75 ~ 2. 2 5 wt% molybdenum, 3.9 0
~ 4.30 wt% tantalum, and 0.0 8 ~0. 13 wt% carbon,
The method for producing a superalloy, characterized in that the balance of the superalloy is nickel. 11. 0.25~0. 35 wt% of zirconium, 0.00
4～0.010Wt% boron, 6.5 0 to 6.7 0 wt% of aluminum, of 9.5 to 1 0.5 0 wt% chromium, 1. 0 5~ 1. 25 wt% of hafnium, 3.00 ~ 3.40 wt% tungsten, 1.75 to 2 . 2 5 wt%
Molybdenum, 3.9 0 to 4.30 wt% tantalum, and 0.0 8
~0. 13 wt% of carbon, containing, manufacturing method of a jet engine construction material, characterized in that the balance comprises the step of casting a nickel superalloy is nickel. 12. The method of claim 11, wherein the superalloy manufacturing method of a jet engine construction material according to claim 1 1, wherein the cast by a single furnace insertion under vacuum. Ingot wherein said superalloy is redissolved in vacuo, followed by the claim 1 2, wherein a to be cast using a precision casting flow baked nickel alloy jet engine construction material Production method.