JP3067416B2 - Ni-based alloy powder for manufacturing high temperature heat resistant parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to Ni used for manufacturing turbine moving blades and vanes of a gas turbine, moving blades of a high-temperature blower and other high-temperature heat-resistant parts by powder metallurgy.
It relates to a base alloy powder.

[0002]

2. Description of the Related Art Turbine blades and vanes of a gas turbine, blades of a high-temperature blower and other high-temperature heat-resistant parts are generally made of Ni-base having excellent high-temperature strength, high-temperature oxidation resistance and high-temperature corrosion or sulfide corrosion resistance. Manufactured by casting alloys. However, in recent years, these high temperature heat resistant parts have begun to be manufactured by powder metallurgy.

[0003] For example, Japanese Patent Publication No. 51-43802 describes a Ni-based alloy powder for producing the high temperature heat-resistant component by powder metallurgy. This Ni-based alloy powder is expressed in terms of% by weight (hereinafter,% indicates% by weight).
50% or less, Cr: 10 to 16%, Co: 7 to 11%,
Mo: 5% or less, W: 7% or less, Nb: 5% or less, T
a: 5% or less, Hf: 5% or less, Zr: 0.01-0.
20%, (however, Mo + W + Nb + Ta + Hf + Zr
= 10 to 12%), Ti: 1 to 5%, Al: 2 to 6%,
B: 0.01 to 0.20%, with the balance being Ni and inevitable impurities. The structure of a high-temperature heat-resistant component manufactured by powder metallurgy using this Ni-based alloy powder is found in conventional cast materials and forged materials despite the fact that about 50% of a precipitated phase called a γ prime phase is contained. It has no such segregation, and has a homogeneous and excellent alloy structure.

[0004]

The high-temperature heat-resistant alloy member manufactured by the powder metallurgy method using the above-mentioned conventional Ni-based alloy powder, when oxygen and sulfur segregate at crystal grain boundaries, embrittles the material and causes tensile properties. It is known to reduce the elongation and creep rupture life in the high temperature heat-resistant alloy members manufactured by powder metallurgy using Ni-based alloy powder, especially compared to other cast alloys due to fine crystal grains The characteristics of the grain boundaries greatly affect the entire material.

In particular, a sintered member manufactured by a powder metallurgy method using a Ni-based alloy powder is further subjected to forging such as hot pressing to produce a sized high-temperature heat-resistant alloy member having improved strength. , Oxygen and sulfur also cause defects such as cracks during the forging.

[0006]

The inventors of the present invention have conducted intensive studies and found that the amount of Cr was slightly increased to 13.1 to 15%,
W, Mo, Al, Ti, Ta, C, B, Zr, etc. are added in a balanced manner as much as possible, and a Ni-based alloy powder containing a total amount of Mg and / or Ca of 1 to 100 ppm is sintered. The resulting sintered member can suppress the adverse effects of impurities such as oxygen and sulfur, has high high-temperature strength, and also has oxidation resistance and corrosion resistance at high temperatures, and further causes defects such as cracks during forging. This led to the discovery that this could be used as a material for a gas turbine component using a low-grade fuel such as heavy oil, leading to the present invention.

[0007] The present invention has been made based on such findings, and includes: Cr: 13.1 to 15.0%, Co:
8.5 to 10.5%, Mo: 1.0 to 3.5%, W:
3.5-4.5%, Ta: 3.0-5.5%, Al:
3.5-4.5%, Ti: 2.2-3.2%, C: 0.
01-0.09%, B: 0.005-0.025%, Z
r: 0.01 to 0.10%, Mg and / or Ca:
1 to 100 ppm, and if necessary, H
f: 0.5 to 1.5%, Pt: 0.05 to 0.5%, R
h: 0.05 to 0.5%, Re: 0.05 to 0.5%, contains one or more of them, with the balance being Ni and unavoidable impurities, high-temperature strength and oxidation resistance And Ni-based alloy powder for producing high temperature heat resistant parts having excellent corrosion resistance.

Next, the reasons for limiting each element in the composition of the Ni-based alloy powder of the present invention will be described in detail.

Cr: 13.1 to 15.0% Industrial gas turbines are required to have high-temperature oxidation resistance and corrosion resistance because they come into contact with combustion gas containing oxidizing and corrosive substances generated by combustion. Cr is an element that imparts oxidation resistance and corrosion resistance to the alloy, and the effect is remarkable as the Cr content in the alloy is increased.

However, when the Cr content is less than 13.1%, the effect is small. On the other hand, in the Ni-based alloy of the present invention, Co, Mo,
Since W, Ta, and the like are also added, it is not preferable to contain more than 15% in order to balance them. Therefore, the Cr content is set to 13.1 to 15.0%.

Co: 8.5-10.5% In a γ ′ precipitation-hardening Ni-based alloy made of Ti, Al or the like, these additional elements are sufficiently dissolved in a substrate by a solution treatment, and then γ ′ in a subsequent aging treatment. Good high-temperature strength can be obtained by precipitating uniformly and finely as a phase.

[0012] Co has the effect of increasing the limit (solid solubility limit) at which Ti, Al, or the like exhibiting such an effect is dissolved in a base material at a high temperature and improving the strength of a Ni-based alloy. In the Al and Ti contents of the alloy according to the above, the Co content needs to be 8.5% or more. On the other hand, if the Co content exceeds 10.5%, Cr, Mo, W, Ta, Al, Ti, etc. The Co content is set to 8.5 to 10.5% because the balance with the element is lost and the ductility is reduced due to the precipitation of the harmful phase.

Ti: 2.2-3.2 % Ti is an element necessary for precipitation of a γ ′ phase for increasing the high-temperature strength of a γ ′ precipitation-hardening Ni-based alloy, and when less than 2.2%, γ ′
The precipitation strengthening of the phase is insufficient and the required strength cannot be satisfied, and if added in excess of 3.2%, the amount of precipitation becomes too large and the ductility is impaired. Therefore, the Ti content is
It was set to 2.2 to 3.2%.

Al: 3.5-4.5% Al is an element that exhibits the same effect as Ti, generates a γ ′ phase, increases high-temperature strength, and contributes to oxidation resistance and corrosion resistance at high temperatures. Has an effect, but its amount is 3.5%
It is necessary that the amount of Ti is more than 4.5%. On the other hand, if the content is excessively large, exceeding 4.5%, the ductility is impaired, so that the Ti content is set to 3.5-4.5%.

Mo: 1.0-3.5% Mo has a function of increasing the high-temperature strength by forming a solid solution in the base material, but if its content is less than 1.0%, it is insufficient.
On the other hand, if added in excess of 3.5%, the ductility due to the precipitation of harmful phases is impaired, so Mo was set to 1.0-3.5%.

W: 3.5-4.5% W has the effect of solid solution strengthening like Mo, and has the effect of contributing to the provision of high-temperature strength, but the amount is required to be 3.5% or more, and too much. If too long, a harmful phase is precipitated, and W is an element having a large specific gravity, so that the specific gravity of the whole alloy becomes large, which is disadvantageous for a turbine rotor blade in which centrifugal force works and the cost is high. Is
3.5-4.5%.

Ta: 3.0-5.5 % Ta contributes to improvement of high-temperature strength by solid solution strengthening and γ ′ phase precipitation hardening, and is effective at 3.0% or more. On the other hand, if added too much, the ductility decreases, so the content was made 5.5% or less.

C: 0.01-0.09% C tends to form harmful carbides at the old powder grain boundaries in the process of densifying the powder, and if added in excess of 0.09%, impairs mechanical properties such as ductility. However, on the other hand, a small amount of C
Is required to be 0.01% or more because it particularly contributes to strengthening of grain boundaries. Therefore, its content was made 0.01-0.09%.

B: 0.005% to 0.025% B increases the bonding force at the crystal grain boundaries to strengthen the base and improves creep rupture characteristics and hot workability, so 0.005%
Although it is necessary as described above, if added in an excessive amount, the ductility may be impaired, so the content was made 0.025% or less.

Zr: 0.01-0.10% Zr also strengthens the substrate by increasing the bonding force at the crystal grain boundaries,
0.010 to improve creep rupture characteristics and hot workability
% Or more is necessary, however, if added in an excessive amount, the ductility may be impaired, so the content is set to 0.10% or less.

Mg and / or Ca: 1-100 ppm Mg and / or Ca have a strong bonding force with impurities such as oxygen and sulfur, and also prevent ductility from being reduced by segregation at the grain boundary of impurities such as oxygen and sulfur. However, if the content is less than 1 ppm, a sufficient effect cannot be obtained. On the other hand, if the content exceeds 100 ppm, Mg and / or Ca are determined to be 1 to 100 ppm because the bonding of the crystal grain boundaries is rather weakened to cause cracking. Was.

Hf: 0.5-1.5% Hf has the effect of forming a stable carbide and preventing harmful carbide precipitation at the old powder grain boundary in the process of densifying the alloy powder, but the content is 0.5%. If the content is less than 1.5%, sufficient effects cannot be obtained.On the other hand, if the content exceeds 1.5%, the ductility and the hot workability are reduced.
It was determined to be 5 to 1.5%.

One or more of Pt, Rh, and Re: 0.
05-0.5% These elements have an effect of improving corrosion resistance, but if the content is less than 0.05%, a sufficient effect cannot be obtained.
If the content exceeds 5%, further effects cannot be expected, and the price increases because of the noble metals, which is not preferable. Therefore, one or more of Pt, Rh, and Re are
It was set to 0.05-0.5%.

The Ni-base alloy powder according to the present invention will be described in more detail with reference to examples.

EXAMPLES Ni-base alloys having the component compositions shown in Tables 1 to 3 were vacuum-melted, and the resulting melts were made into a Ni-base alloy powder by a gas atomization method using Ar gas to obtain a powder having a large particle size. Sift to remove the particles, the particle size of 100μ
Inventive Ni-based alloy powders 1-16, comparative Ni-based alloy powders 1-4, and conventional Ni-based alloy powders 1-2 prepared below m were prepared.

[0025]

[Table 1]Ni-based alloy powder of the present invention  Element 1 2 3 4 5 6 7 8 Cr 13.1 14.0 15.0 13.5 14.5 13.3 14.2 13.8 Co 9.0 8.5 10.1 10.5 9.7 8.8 9.3 9.5 Mo 2.1 1.0 3.5 1.5 2.4 2.7 3.0 1.8 W 4.0 3.5 4.3 3.7 4.5 4.1 3.9 4.2 Ta 3.3 5.4 4.9 3.0 3.8 3.5 3.8 4.5 Al 4.0 3.5 4.3 3.7 4.5 4.1 3.9 4.2 Ti 2.7 2.3 3.2 2.5 2.9 3.0 2.8 2.7 C 0.05 0.06 0.01 0.09 0.03 0.06 0.07 0.05 B 0.020 0.009 0.007 0.025 0.013 0.012 0.010 0.005 Zr 0.060 0.010 0.072 0.069 0.010 0.068 0.010 0.089 Ca 54-5 25 74 34 10 18 Mg 22 98 − 37 5 54 12 72 Hf − − 1.1 0.7 1.2 0.9 0.8 − Pt − − − − 0.5 − − 0.05 Rh − − − − − − 0.3 − Re − − − − − − − 0.4 0.05 Ni remaining remaining remaining remaining remaining remaining remaining remaining % By weight, where Ca and Mg are ppm

[0026]

[Table 2]Ni-based alloy powder of the present invention  Element 9 10 11 12 13 14 15 16 Cr 13.1 14.0 15.0 13.5 14.5 13.3 14.2 13.8 Co 9.0 8.5 10.1 10.5 9.7 8.8 9.3 9.5 Mo 2.1 1.0 3.5 1.5 2.4 2.7 3.0 1.8 W 4.0 3.5 4.3 3.7 4.5 4.1 3.9 4.2 Ta 3.3 5.3 4.9 3.0 3.8 3.5 3.8 4.5 Al 4.0 3.5 4.3 3.7 4.5 4.1 3.9 4.2 Ti 2.7 2.3 3.2 2.5 2.9 3.0 2.8 2.7 C 0.05 0.06 0.01 0.09 0.02 0.05 0.08 0.04 B 0.020 0.009 0.007 0.025 0.013 0.012 0.010 0.005 Zr 0.067 0.010 0.052 0.044 0.096 0.073 0.089 0.077 Ca 54-99 25 74 34 10 18 Mg 22 98-37 5 54 12 72 Hf--1.5 0.7 1.2 0.9 0.8 1.3 Pt 0.05 0.1-0.2 0.06 0.2 0.05 0.08 Rh 0.05 0.2 0.1 0.1--0.09-Re 0.05-0.3-0.07 0.1 0.05 0.2 Ni remaining remaining remaining remaining remaining remaining remaining remaining % By weight, where Ca and Mg are ppm

[0027]

Table 3 Comparative invention Ni-based alloy powder Conventional Ni-based alloy powder Element 1 2 3 4 1 2 Cr 12.5 15.5 14.0 13.5 9.0 13.9 Co 9.0 8.5 10.1 10.5 14.9 7.9 Mo 2.1 1.0 3.5 1.5 3.2 1.9 W 4.0 3.5 4.3 3.7 3.8 2.5 Ta 3.3 5.3 4.9 3.0 1.5 1.2 Al 4.0 3.5 4.3 3.7 5.5 4.0 Ti 2.7 2.3 3.2 2.5 2.7 3.1 C 0.03 0.07 0.01 0.09 0.04 0.06 B 0.020 0.009 0.007 0.025 0.015 0.020 Zr 0.061 0.010 0.088 0.064 0.010 0.015 Ca * 0.5-* 105 25- -Mg-* 0.5-* 110--Nb----1.0 1.0 Hf 1.1 0.5 1.5 0.7 1.3-Pt 0.05-----Rh 0.05 0.5-0.07--Re--0.3--- Ni Remaining Remaining Remaining Remaining Remaining weight%, however, Ca and Mg are ppm . The mark * deviates from the condition of the present invention.

The obtained Ni-based alloy powders 1 to 16 of the present invention were compared.
The Ni-based alloy powders 1 to 4 and the conventional Ni-based alloy powders 1 and 2 were filled in stainless steel cans having an inner dimension of 100 mm in diameter and 100 mm in length, evacuated and sealed to prepare capsules. The obtained capsules are 1100-12
After performing hot isostatic pressure treatment (HIP) at a predetermined temperature of 00 ° C., 1000 atm, and holding for 5 hours to densify the Ni-based alloy powder, a stainless steel can as a capsule material is machined by machining. After removal, the hot isostatic pressure treated body was taken out. The removed hot isostatic pressure treated body has a diameter of 80 mm,
The length was 70 mm.

The above-mentioned hot isostatically treated body having a length of 70 mm is further subjected to a strain rate of 1 × 10 ^{−4 to} 5 × 10 ⁻³ [/ sec. ], A hot press having a diameter of 170 mm and a thickness of 15 mm was produced from a hot isostatic pressure treated body having a length of 70 mm. Whether or not cracks have occurred on the peripheral end surface of the hot pressed body by such hot pressing is visually inspected, and the results are shown in Tables 3 to 5. The obtained hot pressed body is further heated in the air at a temperature of 950 to 1200.
The forged Ni-based sintered alloy member was manufactured by maintaining the temperature at a predetermined temperature in ° C. for a predetermined time in 1 to 30 hours. these
The following high-temperature corrosion resistance test and creep rupture strength test were performed on the Ni-based sintered alloy forged member, and the test results are shown in Tables 3 to 5.

High-Temperature Corrosion Resistance Test Diameter: 10 mm, length: 100 m manufactured from a forged Ni-based sintered alloy having a diameter of 170 mm and a length of 15 mm
m test pieces each containing hydrogen sulfide gas at a temperature of about 110
After being kept in a natural gas flame at 0 ° C. for 1 hour, cooling was repeated 50 times for 30 minutes. After removing the scale formed on the surface of the test piece subjected to such a treatment, the weight loss of the test piece was measured, and the weight of the other test pieces relative to the weight loss of the test piece prepared from the above-mentioned conventional Ni-based alloy powder 1 The ratio of the weight loss was measured, and the high temperature corrosion resistance was evaluated based on the weight loss ratio.

Creep Rupture Strength Test A parallel portion made from a Ni-based sintered alloy forged member having a diameter of 170 mm and a length of 15 mm has a diameter of 6 mm and a length of 2
5 mm test pieces were prepared, and these test pieces were held in an air atmosphere at a temperature of 871 ° C. with a load of 35 kg / mm ² applied thereto, and the life (hour) until breakage was measured.
Assuming that the rupture life of a test piece made from the base alloy powder 1 is 1,
The ratio of the rupture life of the other test pieces was measured, and the high temperature creep rupture strength was evaluated.

[0032]

[Table 4]

[0033]

[Table 5]

[0034]

From the results shown in Tables 1 to 5, Cr was converted to
13.1 to 15.0% and W, Mo, Al, Ti, T
a, C, B, Zr, etc. are added in a well-balanced manner, and Mg and / or Ca are further added in an amount of 1 to 100 ppm.
Hf, Pt, Rh, Re if necessary.
Ni-based sintered alloy hot-pressed body obtained by sintering a Ni-based alloy powder having a composition containing: has excellent corrosion resistance at high temperatures without cracking during hot pressing and It can be seen that the high temperature creep rupture strength is also excellent.

Therefore, the Ni-based alloy powder obtained by the present invention is excellent not only in high-temperature strength but also in high-temperature oxidation resistance and high-temperature corrosion resistance, and is in contact with a combustion gas containing an oxidizing substance. It is particularly useful as a raw material powder for producing a moving blade and a stationary blade, a moving blade of a high-temperature blower, and other high-temperature heat-resistant parts by powder metallurgy.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ichiro Tsuji 2-1-1, Shinhama, Arai-machi, Takasago City, Hyogo Prefecture Inside Mitsubishi Heavy Industries, Ltd. Takasago Works (72) Inventor Koji Takahashi 2-1-1, Araimachi, Takarai City, Hyogo Prefecture No. 1 Inside the Takasago Works, Mitsubishi Heavy Industries, Ltd. (72) Inventor Taiji Torigoe 2-1-1, Niihama, Araimachi, Takasago City, Hyogo Prefecture Inside the Takasago Works, Mitsubishi Heavy Industries, Ltd. (72) Inventor Masahiro Wada 1--1, Kitabukurocho, Omiya City, Saitama Prefecture 297 Mitsubishi Materials Corporation Central Research Laboratory (72) Inventor Takeaki Sadai 1-297 Kitabukurocho, Omiya City, Saitama Prefecture Mitsubishi Materials Corporation Central Research Laboratory (72) Inventor Akira Mitsuhashi 1-297 Kitabukurocho, Omiya City, Saitama Mitsubishi (56) References JP-A-50-77203 (JP, A) JP-A-49 106408 (JP, A) JP Akira 52-72321 (JP, A) JP Akira 59-110755 (JP, A) Tokuoyake Akira 51-43802 (JP, B2) (58) investigated the field (Int.Cl. ⁷ , DB name) B22F 1/00 C22C 19/05

Claims (4)

(57) [Claims] 1. A weight percentage of Cr: 13.1 to 15.0%, Co: 8.5 to 1
0.5%, Mo: 1.0 to 3.5%, W: 3.5 to 4.5
%, Ta: 3.0-5.5%, Al: 3.5-4.0.
5%, Ti: 2.2 to 3.2%, C: 0.01 to 0.2%
09%, B: 0.005 to 0.025%, Zr: 0.01 to
0.10%, containing Mg and / or Ca: 1 to 100 ppm,
A Ni-based alloy powder for producing a high-temperature heat-resistant component, the balance being composed of Ni and unavoidable impurities. 2. In weight%, Cr: 13.1 to 15.0%, Co: 8.5 to 1
0.5%, Mo: 1.0 to 3.5%, W: 3.5 to 4.5
%, Ta: 3.0-5.5%, Al: 3.5-4.0.
5%, Ti: 2.2 to 3.2%, C: 0.01 to 0.2%
09%, B: 0.005 to 0.025%, Zr: 0.01 to
0.10%, contains Mg and / or Ca: 1 to 100 ppm, further contains Hf: 0.5 to 1.5%, and the balance is composed of Ni and unavoidable impurities. Ni-based alloy powder for manufacturing high temperature heat resistant parts . 3. A weight percentage of Cr: 13.1-15.0%, Co: 8.5-1.
0.5%, Mo: 1.0 to 3.5%, W: 3.5 to 4.5
%, Ta: 3.0-5.5%, Al: 3.5-4.0.
5%, Ti: 2.2 to 3.2%, C: 0.01 to 0.2%
09%, B: 0.005 to 0.025%, Zr: 0.01 to
0.10%, Mg and / or Ca: 1 to 100 ppm, Pt: 0.05 to 0.5%, Rh: 0.05 to 0.5
%, Re: 0.05 to 0.5%, a Ni-based alloy powder for producing a high-temperature heat-resistant component , characterized in that it contains one or more of 0.05 to 0.5%, and the balance has a composition consisting of Ni and unavoidable impurities. 4. A weight percentage of Cr: 13.1 to 15.0%, Co: 8.5 to 1
0.5%, Mo: 1.0 to 3.5%, W: 3.5 to 4.5
%, Ta: 3.0-5.5%, Al: 3.5-4.0.
5%, Ti: 2.2 to 3.2%, C: 0.01 to 0.2%
09%, B: 0.005 to 0.025%, Zr: 0.01 to
0.10%, Mg and / or Ca: 1 to 100 ppm, Hf: 0.5 to 1.5%, Pt: 0.05 to 0.5%, Rh: 0 .05-0.5
%, Re: contains 0.05% to 0.5% one or more of, Ni-based alloy powder for high temperature resistant component manufacturing and having the balance consisting of Ni and unavoidable impurities.