JPS5976839A - Heat resistant composite alloy member and its production - Google Patents

Abstract

PURPOSE:To develop a composite alloy member which permits the use in a high temp. part in the stage of joining members of a sintered alloy and a heat resistant alloy and producing a heat resistant composite alloy member by penetrating beforehand B in the joining part of the heat resistant ally member then subjecting said member to diffusion joining with the sintered alloy member. CONSTITUTION:A blade or nozzle for a gas turbine is produced by constituting the part to be exposed to a particularly high temp. of a sintered alloy and the part continuous therewith of an ordinary heat resistant alloy, whereby the cost of production is reduced. An oxide dispersion-reinforced alloy of Ni or Co base, a fiber-reinforced alloy, unidirectionally solidified alloy, single crystal metal, etc. are used for the sintered alloy, and an Ni alloy contg. 0.05-0.20% C, <1% Si, <1% Mn, 10-25% Cr, 2-10% >=1 kinds of Mo and W, 0.5-7% Al and Ti respectively, and 0.005-0.05% B is used for the heat resistant alloy. B is penetrated at <=0.2% in the joining part of such heat resistant alloy and the sintered alloy is brought into contact with the surface thereof, then the members are heated in a non-oxidative atmosphere, whereby the diffusion joining is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a new heat-resistant composite alloy member, and particularly to a member suitable for gas turbine blades and nozzles.

[Prior art]

Conventionally, heat-resistant parts for gas turbines, such as rotor blades, stationary blades, and combustors, all have the same composition and are usually made of a single piece of polycrystalline heat-resistant alloy produced by melting.

As shown in FIG. 1, the rotor blade includes a blade section 1, a shank section 2, and a dovetail section 3, all of which are made of an r'-phase precipitation-strengthened Nt-based heat-resistant alloy that is precision cast by vacuum melting.

[Problems with conventional technology]

In recent years, as the efficiency of gas turbines has improved, it has become essential to raise the working temperature of rotor blades, but polycrystalline Ni-based alloys produced by conventional vacuum melting and precision casting lack high-temperature strength, making gas turbines at higher temperatures. Can not do it. This problem t'',
The same is true for Shizume and combustors. As a method to solve this problem, gas turbine parts are cooled by air or water to lower the metal temperature of the parts, thereby raising the overall temperature of the gas turbine. Although this cooling method is effective to some extent,
If the amount of cooling medium is too large, it will not be possible to lower the gas temperature, but will instead reduce thermal efficiency. ,! In the combustor, a thermal barrier coating is applied to the surface of the combustor to lower the metal temperature, thereby achieving a certain degree of high temperature. However, with both the cooling method and the thermal barrier coating, the temperature that can be raised is at most several tens of degrees Celsius, and the gas temperature is 1,300 to
This alone is not sufficient to achieve a high temperature gas turbine of 1500c.

Well, the problem is being solved by using alloys. −
For example, oxide dispersion strengthened alloys exhibit significantly less strength loss at temperatures above 850C than heat-resistant alloys, and also have excellent thermal fatigue resistance, oxidation resistance, and sulfide corrosion resistance, making them extremely suitable for high-temperature gas turbine components. , and has attracted particular attention in recent years. It is already used in some jet engines. The manufacturing process for this oxide dispersion strengthened alloy is complex and varied, so it is extremely difficult to manufacture it, especially for gas turbine parts for power generation, which are large structures.

[Outline of invention cost]

(Objective of the Invention) An object of the present invention is to provide a heat-resistant composite alloy member and a method for manufacturing the same, which can be used at high temperatures with less decrease in strength of joints.

(Summary of the Invention) The present invention provides a superalloy member made of one of oxide dispersion strengthened alloy parts, materials, fiber reinforced alloy members, directionally solidified alloy members, and single crystal metal members, and 1. 1. The superalloy member is a composite member formed by diffusion bonding with a metal interposed therebetween that is alloyed with these alloy members to form a melting point lower than that of the superalloy member, and the bonded portion of the superalloy member is bonded. The percentage indicates that the previous tissue is maintained.

As a result of investigating the temperature fc of gas turbine blades in use, the inventors found that there is a difference of several hundred C between the maximum and minimum temperatures.
It was found that the temperature gradient of For example, if the gas temperature is 1100C, the blade tip of the moving plate is 9201? ,
Approximately 400C at the tail part, and the leading edge part at the tip of the wing is approximately 1 x 1
50 tons? I discovered something. From this, the inventors determined that the metal temperature exceeds the operating temperature of the above-mentioned superalloy members in a part of the blade tip of the rotor blade, and that in other parts of the rotor blade, the metal temperature exceeds the operating temperature of the previously used heat-resistant alloy members other than the superalloy members. We focused on the fact that it can be used sufficiently. For this purpose, the high temperature part is made of the above-mentioned superalloy member, the part at a lower temperature is made of the conventionally used heat resistant alloy member, and by diffusion bonding these parts, a much higher temperature can be achieved as a whole member.

Oxide dispersion strengthened alloys, fiber reinforced alloys, unidirectionally solidified alloys,
Since all superalloy parts of crystalline metal parts are strengthened by a special arrangement of alloys, it goes without saying that if these regularities are broken, the strength will be extremely reduced. Therefore, it has been found that when joining with heat-resistant alloys other than these superalloys, high strength IW cannot be obtained unless this regularity is disrupted at the joint.

It is extremely difficult to restore these regularity disruptions by any other means such as post-bonding heat treatment! The structure of general heat-resistant alloys can be improved by heat treatment.

Conventionally, diffusion bonding was carried out through metal parts that were alloyed and had a melting point lower than that of the base metal, such as 8.8i foil or powder, so the two metal parts at the bonding interface were alloyed. The method used was always to melt the material and then perform a diffusion treatment.

However, this method has the problems described above, and the strength of the joint is low.

In the present invention, the problem is solved by forming a metal with a low melting point on another heat-resistant alloy (11!I) so that the original structure at the joint of the superalloy members is not destroyed. Since the alloy member does not have any melting parts and is joined only by solid diffusion of metal such as B, a highly strong composite alloy member can be obtained.

Oxide dispersion strengthened alloys, fiber reinforced alloys, unidirectionally solidified alloys,
It is after 850C that the crystalline metal parts I and I do not exhibit this characteristic.
Therefore, it is best to place these superalloy members and heat-resistant alloys in a place where the temperature of all parts is below 850C.At temperatures below 3850C, heat-resistant alloys have better strength and ductility than these superalloy members. As a result, a more balanced member can be obtained.

(Manufacturing method) In particular, in the diffusion bonding of the present invention, holon is infiltrated in advance,
After that, it is preferable to perform a bonding method that involves diffusion.

In particular, at first, the heat-resistant alloy is infiltrated only into the joint surface.
Next, it is important to set the superalloy member on the joint surface of the heat-resistant alloy and perform diffusion bonding. Even if the bonding surface of the two is infiltrated with a bolt 17 and heated only to the bonding surface of the superalloy part, and then diffusion bonding is performed, an unfused portion will be formed on the bonding surface, which is not preferable. The reason why there are so many non-+11 bonded parts is that, for example, when an oxide dispersion strengthened alloy is impregnated with B, the surface is unclean due to a large oxide film. In addition, boride may be generated on the diffusion bonding surface, but if there is a large amount of boride, it will cause a decrease in high-temperature ductility, so the width of boride precipitation should be 20 μm.
It is preferable to keep it within. The amount of boride varies depending on the boron 11 at the time of boron infiltration, the diffusion temperature and holding time during diffusion bonding, but the most important factor is the amount of boron in the boron permeation layer.

If the amount of boron is 15% or more, the subsequent diffusion bonding treatment at high temperatures may result in boron diffusion being insufficient.
It begins to precipitate to a size of 0 μm or more. Also, the amount of boron is 1
If it exceeds 5%, it is not preferable because it combines with Cr in the matrix to form Cr boride, which is not eliminated even by diffusion treatment. In diffusion bonding, if the amount of boron is too low, the bonding rate can be improved by applying a load M, but if the amount of boron is selected appropriately, it can be done without spending any money.

If the amount of B in the joint after diffusion treatment exceeds 0.2%, the creep rupture strength will decrease, so the amount of B should be less than 2"10.
It is better to set it below.

(Combination b of heat-resistant composite parts) A PE-based ausanite alloy is used for the combustor liner phase.

The C content of the alloy should be 0.05 or more from the viewpoint of high temperature strength, but it is 0.
．． If it exceeds 2%, workability will decrease, so 0.05 to 0.
．． 2% is preferred. Cr is 20 to 4 from the viewpoint of high temperature corrosion resistance.
0%, Ni is required in an amount of 15 to 50% to obtain stable heat resistance and an austenitic structure. On the other hand, compared to this alloy, the composition of the oxide dispersion strengthened alloy is 0.3 to 8% Y2O3 from the viewpoint of high temperature strength and 0.2 to 0.0% from the viewpoint of workability.
An alloy containing 8% Ti1, 3 to 6% Pano 5 from the viewpoint of oxidation resistance, 15 to 25% Crff1 from the viewpoint of corrosion resistance, and the balance consisting of Ni is optimal.

Heat-resistant alloys for gas turbine statics include carbide precipitation-strengthened CO-based and Ni-based alloys (r/phase precipitation-strengthened Ni-based alloys). Carbide precipitation strengthened type 1 alloy r, t, from the point of view of high strength and ductility, C091~0.6''/.

W5~1-0 electric inertia, Co15~35%, Cr20=40% LUFlii as the basic component from the viewpoint of corrosion resistance 7-/In the case of phase precipitation strengthened Nt-based alloy, A11 with r' phase-forming element ~3′! 4. T12~5%, C) from the viewpoint of high temperature strength, c O, 05~0.2%, 0017~
22%, and preferably 15 to 25% Cr from the viewpoint of high temperature corrosion resistance. The oxide dispersion strengthened alloy for this stator blade is Y2030, 3 to 1.5 in terms of high grade strength and thermal fatigue resistance.
%CO,02-,0,15%Al
From the viewpoint of corrosion resistance, it is preferably composed of 0.2 to 5% Cr, 15 to 25% Cr from the viewpoint of corrosion resistance, and 13 to 0.7% Ti and the balance Nt from the viewpoint of workability.

An r'-phase precipitation strengthened Ni-based alloy is used as the heat-resistant alloy in Dogo, and its components include A13, which is a γ'-forming element.
~6%, 't'ti ~4%, to Cr6 for high temperature corrosion resistance, 17.9, high temperature strength and castability all considered 1, C0,05
It is preferable to set it as 0.15%. On the other hand, oxide dispersion strengthened alloy No. 1 needs to have higher high temperature strength than those used for the combustor liner and stator blade material, and Y*Os is 0.71 to 1.
．． 5%, and furthermore, to strengthen the base, the r' phase forming elements are At3-6%, T11-4%, C0.02-0.
15%, Ta 1-3%, W 2-6%, grain boundary strong element Z r 0.1-0.3%, 80.02-0.2%, Cr 12-18' Chaos residue for high temperature corrosion resistance The one with Ni is preferable.

A/, 0.5 in place of the oxide dispersion strengthened alloy described above
~6%, Tio, 5~6%, C0,02~0
．． Directionally solidified superalloy consisting of 0.5~20% Cr, 5~20% Cr, and the balance Nt, At 0.5~6%
, TiO, 5-6%, 0103-20%, Cr5-20
%, the balance being Ni, and the fiber-reinforced superalloy in which fibers made of the aforementioned gas are dispersed can be used in the same way.

For both unidirectionally solidified superalloys and fiber-reinforced superalloys, it is necessary that the direction in which the tensile force is applied coincides with the direction of solidification in the former and the length direction of the fibers in the latter.

[Embodiments of the invention]

Example 1 FIG. 1 is a perspective view of a static spectrum for a gas turbine to which alloy 1&: of the present invention is applied. 27, 2 g, 2// in wing part 2
/ is a part exposed to 850C or higher, up to 1100C
may reach. M spring, 0.25%C130%C
A Co-based heat-resistant alloy consisting of r, 7.7% W%, 0.012% B, 10.5% N1, and the balance co is melted in vacuum, precision cast using the lost wax method, and the joint surfaces are finished with emery paper. Polished to +SOO. Then, by weight, 2o
%Cr 0.6 %Yz Os, 0,3 %A t, 0
．． Component 2/ of FIG.
21/, 2"' was molded. Next, f other than the joint surface of the wing part 2
7 Sprinkle, 1% B - 2,5% NH*C1 - Remainder A
It was embedded in a mixed powder made of 12O5 powder and heated at 850 Cxah in Ar. Next, the B permeation surface t' of the joint surface was lightly honed and further washed with water. Carefully align the joint surfaces with each other, fix them with a jig so that they do not move, apply pressure, and heat them in Ar at 1,200? ,”X3h
Diffusion treatment was performed. Next, heat treatment of the CO-based heat-resistant alloy 1.150CX2h→cooling, 982UX4b→air cooling was performed to obtain the cold slt for gas turbine shown in the figure. Bonding is done only on the wing section 2, and is not done on the sidewall 1°1". It was found that this allows the operating temperature of the stator vane to be raised by about 150C. As a result of microscopic observation of the joint section, it was found that the section without polide was bonded. It was a uniform organization.

Example 2 Figure 2C shows a gas turbine lu υ to which the alloy of the present invention is applied.
FIG. 2 is a perspective view of a wing. The tip part of wing part 3-C3' is 850
exposed to temperatures above C. 3' is the 17'4 position of the wing section 3. This partial gold amount is 15% Cr, 1.1% ¥2
03.4.5%At, 2.5%Ti12%T'a, 2
%Mo, 4%W, 0.1%Zr, 0.0
It was made from an oxide-dispersed alloy of 1% BIBalNi. Next, except for 3', the wing part 3", shank 4, and dovetail 5 parts were made of 0.1% C, i% Co, 16.2% Cr by weight.
.

2.7% W, 2% M O, (1, Q6') Z r,
J2''/i+ Al*3, C34"shi θIll i
It was manufactured by applying and melting the NN-based heat-resistant base metal with the remaining Ni, and by Xun Midiao construction. This heat-resistant alloy C) becomes shallower;
Masking the areas other than the contact area MJ, it was diffused and infiltrated in the same manner as in Example 1 of Actual JJ 14.

Diffusion bonding was performed in the same manner as described above under pressure. Then, N
! 1,121C x 2h, similar to the heat treatment of base ij heat base metal →
Nitrogen cooling, 843 tl, 'X24h→Visual cooling was performed. FIG. 3 shows that as a result of observing the microstructure of the joint, a good joint was obtained. As a result, better and more balanced performance than that of a rotor blade made of an alloy reinforced with oxidized oxides was obtained.

Example 3 Instead of the oxide dispersion strengthened superalloy of Example 1, a diameter of 0.
A sample of a fiber-reinforced superalloy produced by impregnating a 4 mI Wa bundle with a molten Nl-based alloy containing 20 xtt'poCrk was diffusion bonded in the same manner as in Example 1. Heating for diffusion bonding was performed in a vacuum, and after bonding, the same heat treatment as in Example 1 was performed. The area ratio of the W wire was 75%, and the fiber-reinforced alloy was joined at the end face of the fiber. According to this composite alloy, the usability of stator blades for gas turbines can be reduced by approximately 10%.
You can get 0C.

Example 4 Instead of the oxide dispersion strengthened alloy of Example 2, a diameter of 0.4
A bunch of fighting W lines with iL guys, W2.5%, Cr15%.

At2">6+ T I 2' glaze was impregnated with a molten alloy consisting of the remainder Ni, and the fiber-reinforced gold alloy with a W area ratio of 90% was bonded by υ diffusion bonding in the same manner as in Example 2. The surface was the shoulder surface of the fiber, and after bonding, processing was performed to λ similar to Example 2 and "C1".

According to this double 8 base metal, the operating temperature f' of the gas turbine rotor blade is
k150t? I can crystallize it. Note that it is preferable that the entire rotor blade be coated with platinum with a thickness of 10 μm.

Example 5 In place of the oxide dispersion strengthened alloy of Example 1, the group was
S? o, 'riz, s%, C0,15%, W 12
”io.

Co 10'3'o, Cr9'3'o, 1N 1.
A directionally solidified alloy consisting of 8%, 80.02%, Zr 0.08%, and the balance Ni was diffusion bonded by the same method as in Example 1. The bonding was performed by heating at 1.23 I' in a solid wall at 211° C., and the bonding surface was made between /1 and 211 mm during the solidification process. After joining, aging treatment by 982CX 4h heating and 8
Aging treatment was performed by heating for 71t; x20h. This composite alloy can lower the operating temperature of gas turbines by approximately 1
00C can be made to look tall.

Example 6 Instead of the oxide fractionally strengthened alloy of Example 2, with an amount of ijh,
CrlO%, At5%, 1'11.5%, Ta12
A single crystal member consisting of 10% W, 4% W, and the remainder tqr was diffusion bonded by the same method as in Example 1. After bonding, the operating temperature of 1079CX4h can be raised by about 100C.

〔Effect of the invention〕

According to the present invention, a composite alloy member with high bonding strength can be obtained! It is possible to significantly increase the operating temperature of the 11J blades and stationary blades for the Samurai gas turbine.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an example of a gas turbine using the alloy of the present invention at -51, and Fig. 2 is a fi view of an IS F4 for a gas turbine to which the alloy of the present invention is applied. 1.1'...Side wall, 2,3...Todorobu, 4
...Shank, 5...Dovetail, 2/, 2 L
/ , 2r1/ , 3'/ 3-1-1 Saiwaimachi, Hitachi City
No.Hitachi, Ltd., Hitachi Research Institute

Claims (1)

[Claims] 1. A superalloy member consisting of one of an oxide dispersion reinforced alloy member, a fiber reinforced alloy member, a directionally solidified alloy member, and a single crystal metal member, and a heat-resistant alloy member other than the superalloy member. , a member that is diffusion bonded with a metal that is alloyed with these alloy parts and lowers the melting point of the alloy member, and the superalloy joint part must maintain its structure before joining. Features a heat-resistant composite alloy member. 2. The metal is poron, and the amount of boron in the joint is 0.
The heat-resistant composite alloy member according to claim 1, wherein the content is 2% by weight or less. 3. The heat-resistant composite according to claim 1 or 2, wherein the composite member is a blade for a gas turbine, and at least 1/4 of the tip portion of the blade portion is constituted by the superalloy phase. Alloy parts. 4° Said blade has at least the remainder of its distal end portion 1/4-+dil'+, it of CO,05 to 0.2
'10. 841% or less, Mn 1% or less, Cr 10-25%. Mo and W over 11ft 2-1O%, AtO, 5-7
%, Ti0.5-7%, 80.005-O, o5'3.
, and the remainder is Ni, the amount of Az-t-'ri is 3 to 1
4. The heat-resistant composite alloy member according to claim 3, which is made of a Ni-based hooked alloy strengthened by precipitation of 0% and r' phase. 5. The heat-resistant alloy member according to claim 1 or 2, wherein the composite member is a gas turbine nozzle, and at least the trailing edge portion of the blade portion thereof is made of the superalloy member. 6. The nozzle has a weight of C0.1 to 0.6%, excluding at least the trailing edge of its wing. Si2% or less, Mn2% or less, Cr2O~40%. C010-35%, 5-10% of one or more of MO and W,
The heat-resistant alloy part according to item 5 of the scope of patent MrJ, consisting of a Co-based cast alloy strengthened by precipitation of Bo, 0.005 to 0.05%, balance Ni, eutectic carbide and secondary cinnamate. . 7. The nozzle has a carbon content of 0.2 to 0.6%, except for at least the trailing etch portion of the wing. Cr 20-40', Ni 5-15%, one or more of Mo and W 5-10%, Bo, 005-0.05% balance C
Claim 5 consisting of a Ni-based cast alloy strengthened by the precipitation of eutectic carbides and secondary carbides.
The heat-resistant composite alloy member described in . 8. The oxide dispersion strengthened alloy member has a weight of C0,0
2-0.2%, y, oso, a-1.5%, Ti002
~5%, AtO, 2~6%, Cr12~25%,
A Fe-based, Ni-based or Co-based superalloy containing at least 40% of at least one of Fe, Ni and CO
[The heat-resistant composite alloy member according to any one of claims 1 to 7. 9. The directionally solidified alloy member has a weight of C0.02~0
．． 2%, 811% or less, Mn 1% or less, Cr5-20%
, A10.5-6%, lo, s-6% IMO and 1 of W
2-10% of seeds and above, C05-20%. Claims 1 to 7 have a cast structure solidified in one direction, with the remainder being Ni, and a surface perpendicular to the growth direction of the cast structure is joined to the heat-resistant alloy member. The heat-resistant composite alloy member according to any one of Items 1-2. 10. The single crystal metal member has A12 to 7% by weight,
Ti3-6%, Cr6-20%, Ta5-15% and 6
The heat-resistant composite alloy member according to any one of claims 1 to 7, comprising a Ni-based alloy containing 40% or more of Ni and 40% or more of Ni. 11. A superalloy member made of one of the following: an oxide dispersion reinforced alloy member, a fiber reinforced alloy member, a directionally solidified alloy member, and a single crystal metal member; In the method of diffusion bonding using a metal that is alloyed with a member and lowers the melting point of the alloy member, the gold rt is pre-diffused into the bonding surface of the heat-resistant alloy member, and the superalloy member is applied to that surface. A method for producing a heat-resistant composite alloy member, which comprises contacting the member and heating it in a non-oxidizing atmosphere. 12. The method for manufacturing a heat-resistant composite alloy member according to claim 11, wherein pressure is applied between joint surfaces of the alloy member during the heating. 13. Embed the heat-resistant alloy in a powder made of the metal and a diffusion promoter that reacts with the metal and gasifies at a temperature at which it diffuses and permeates, and heat it at a predetermined temperature in a non-oxidizing atmosphere. The method for manufacturing a heat-resistant composite alloy member according to claim 11 or 12, wherein a diffusion permeation layer of the metal is formed on the joint surface. 14. The heat-resistant composite according to any one of claims 11 to 13, wherein the diffusion permeation layer has a B content of 5 to 15% by weight on the outermost surface and a thickness of 5 to 20 μm. Manufacturing method for alloy parts.