JP2022106532A - Alloy powder for deposition modeling, deposition model, and deposition modeling method - Google Patents

Abstract

To improve high-temperature creep ductility in deposition modeling of Ni-based alloys.SOLUTION: An alloy powder for deposition modeling according to one embodiment of the present invention is configured from a nickel-based alloy and contains 15.0 mass% or more and 25.0 mass% or less of cobalt, 10.0 mass% or more and 25.0 mass% or less of chromium, 0.0 mass% or more and 3.5 mass% or less of molybdenum, 0.5 mass% or more and 10.0 mass% or less of tungsten, 1.0 mass% or more and 4.0 mass% or less of aluminum, 0.0 mass% or more and 5.0 mass% or less of titanium, 0.0 mass% or more and 4.0 mass% or less of tantalum, 0.0 mass% or more and 2.0 mass% or less of niobium, 0.03 mass% or more and 0.2 mass% or less of carbon, 0.003 mass% or more and 0.05 mass% or less of boron, and 0.1 mass% or more and 0.3 mass% or less of zirconium.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to alloy powders for additive manufacturing, additive manufacturing bodies, and additive manufacturing methods.

In recent years, a layered manufacturing method for obtaining a three-dimensional shape by additive manufacturing of metals has been used as a method for manufacturing various metal products. For example, in the additive manufacturing method by the powder bed method, a three-dimensional shape is formed by repeatedly laminating by melting and solidifying by irradiating a metal powder laid in a layer with an energy beam such as a laser beam or an electron beam.
In the region irradiated with the energy beam, the metal powder is rapidly melted and then rapidly cooled and solidified to form a solidified metal layer. By repeating such a process, a three-dimensionally shaped laminated model is formed.

On the other hand, it is known that Ni-based alloys containing Ni as a main component have high heat resistance and high high-temperature strength. It is widely used in heat-resistant materials that require high-temperature strength.

Recently, as a method for manufacturing a part made of a Ni-based alloy having a complicated shape such as a turbine blade, an attempt has been made to apply a layered manufacturing method that enables direct molding without going through a complicated manufacturing process (for example). Patent Document 1 etc.).

Japanese Unexamined Patent Publication No. 2018-168400

In the γ'phase-reinforced Ni-based alloy, since the strength in the crystal grains is relatively high, the strength of the crystal grain boundaries is relatively low, and there is a tendency for the γ'phase-reinforced Ni-based alloy to be easily broken at the crystal grain boundaries. Therefore, the high temperature creep ductility may decrease. When the creep ductility is reduced, the stress-concentrated part is liable to break brittlely, and the allowable stress in design is significantly reduced.
In the additive manufacturing of Ni-based alloys produced by the additive manufacturing method, the crystal grains become relatively fine due to rapid solidification after irradiation with the energy beam. Therefore, since the crystal grain boundary area per unit volume is larger than that of the conventional cast material, the influence of the crystal grain boundary on the strength of the laminated model is large.

At least one embodiment of the present disclosure aims to improve high temperature creep ductility in a laminated model of a Ni-based alloy in view of the above circumstances.

(1) The alloy powder for laminated molding according to at least one embodiment of the present disclosure is
An alloy powder for laminated molding composed of a nickel-based alloy.
Cobalt of 15.0% by mass or more and 25.0% by mass or less,
With 10.0% by mass or more and 25.0% by mass or less of chromium,
With molybdenum of 0.0% by mass or more and 3.5% by mass or less,
Tungsten of 0.5% by mass or more and 10.0% by mass or less,
Aluminum of 1.0% by mass or more and 4.0% by mass or less,
With titanium of 0.0% by mass or more and 5.0% by mass or less,
With tantalum of 0.0% by mass or more and 4.0% by mass or less,
Niobium of 0.0% by mass or more and 2.0% by mass or less,
With carbon of 0.03% by mass or more and 0.2% by mass or less,
With boron of 0.003% by mass or more and 0.05% by mass or less,
Zirconium of 0.1% by mass or more and 0.3% by mass or less,
Contains.

(2) The laminated model according to at least one embodiment of the present disclosure is
It is a laminated model made of nickel-based alloy.
Cobalt of 15.0% by mass or more and 25.0% by mass or less,
With 10.0% by mass or more and 25.0% by mass or less of chromium,
With molybdenum of 0.0% by mass or more and 3.5% by mass or less,
Tungsten of 0.5% by mass or more and 10.0% by mass or less,
Aluminum of 1.0% by mass or more and 4.0% by mass or less,
With titanium of 0.0% by mass or more and 5.0% by mass or less,
With tantalum of 0.0% by mass or more and 4.0% by mass or less,
Niobium of 0.0% by mass or more and 2.0% by mass or less,
With carbon of 0.03% by mass or more and 0.2% by mass or less,
With boron of 0.003% by mass or more and 0.05% by mass or less,
Zirconium of 0.1% by mass or more and 0.3% by mass or less,
Contains.

(3) The laminated modeling method according to at least one embodiment of the present disclosure includes a step of forming a laminated model by laminating modeling using the alloy powder for laminating modeling having the configuration of (1) above.

According to at least one embodiment of the present disclosure, high temperature creep ductility in a laminated model of a Ni-based alloy can be improved.

It is a figure which showed the structure after the heat treatment about the laminated model of the Ni-based alloy manufactured by the additive manufacturing method using the alloy powder for laminated modeling which concerns on some embodiments. It is a table which shows the composition of the alloy powder for laminated molding which concerns on some embodiments. It is a table which shows the component, composition, and the result of the high temperature creep test about Example and comparative example using the alloy powder for laminated molding which concerns on some Embodiments. It is a flowchart which shows the manufacturing procedure of the laminated model using the alloy powder for laminated model which concerns on some embodiments. It is a flowchart for demonstrating the heat treatment in the step which performs the heat treatment which concerns on some Embodiments.

Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure, but are merely explanatory examples. do not have.
For example, expressions that represent relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" are exact. Not only does it represent such an arrangement, but it also represents a state of relative displacement with tolerances or angles and distances to the extent that the same function can be obtained.
For example, expressions such as "same", "equal", and "homogeneous" that indicate that things are in the same state not only represent exactly the same state, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the existing state.
For example, an expression representing a shape such as a quadrangular shape or a cylindrical shape not only represents a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also an uneven portion or chamfering within a range in which the same effect can be obtained. The shape including the part and the like shall also be represented.
On the other hand, the expressions "equipped", "equipped", "equipped", "included", or "have" one component are not exclusive expressions that exclude the existence of other components.

In the γ'phase (gamma prime phase) reinforced nickel-based alloy, since the strength in the crystal grains is relatively high, the strength of the crystal grain boundaries is relatively low, and it tends to be easily broken at the crystal grain boundaries. .. Therefore, the high temperature creep ductility may decrease.
In the nickel-based alloy laminated model manufactured by the laminated molding method, the crystal grains are finer than those of the conventional casting of the nickel-based alloy produced by casting because of rapid solidification after irradiation with the energy beam.
In the γ'phase-reinforced nickel-based alloy, the strength characteristics at a temperature lower than 500 ° C. tend to be improved as the crystal grain size is smaller. However, if the crystal grain size is small, the grain boundary area per unit volume becomes larger than that of the conventional cast material, so that the influence of the crystal grain boundaries on the strength of the laminated model becomes large. In order to suppress the influence of the crystal grain boundaries on the strength of the laminated model, it is conceivable to coarsen the crystal grains by heat treatment, but if the crystal grain size is increased, the strength characteristics at a temperature lower than 500 ° C. deteriorate. There is a risk.

As a result of diligent studies by the inventors, boron is effective in improving high-temperature creep strength and creep ductility by strengthening grain boundaries by being present at grain boundaries, and by adding 0.003% by mass or more, grain boundaries. It was found that the strengthening effect was increased. On the other hand, it was found that if the addition amount exceeds 0.05% by mass, boride may be formed and the ductility may be lowered.
Further, as a result of diligent studies by the inventors, it has been found that zirconium is effective in improving high-temperature creep strength and creep ductility by strengthening grain boundaries by being present at grain boundaries. When the crystal grains are fine particles of less than 2.0 mm, satisfy the following formula (A), and the volume ratio of the γ'phase is 15% or more, the amount of zirconium added is less than 0.1% by mass. The grain boundary strength is relatively low as compared with the intragranular strength, and the ductility is lowered. On the other hand, if the amount of zirconium added exceeds 0.3% by mass, the local melting point at the grain boundary may be lowered to cause a decrease in strength.
The above-mentioned formula (A) is expressed as follows. When the parameter for the aluminum content is Al mass%, the parameter for the titanium content is Ti mass%, and the parameter for the tantalum content is Ta mass%, the formula (A) is as follows. Is.
Al + 0.56 x Ti + 0.15 x Ta> 4.0 ... (A)

Based on these points, as a result of diligent studies by the inventors, when the composition of each element is set to the following composition in the alloy powder for laminated molding composed of nickel-based alloy, the crystals in the laminated molding 1 (see FIG. 1) It has been found that the grain boundaries can be strengthened to improve creep strength and creep ductility.
Specifically, in the alloy powder for laminated molding composed of a nickel-based alloy, 15.0% by mass or more and 25.0% by mass or less of cobalt and 10.0% by mass or more and 25.0% by mass or less of chromium are used. , 0.0% by mass or more and 3.5% by mass or less of molybdenum, 0.5% by mass or more and 10.0% by mass or less of tungsten, 1.0% by mass or more and 4.0% by mass or less of aluminum, 0 0.03% by mass or more and 5.0% by mass or less of titanium, 0.0% by mass or more and 4.0% by mass or less of tantalum, 0.0% by mass or more and 2.0% by mass or less of niobium. It is preferable to contain carbon of mass% or more and 0.2 mass% or less, boron of 0.003 mass% or more and 0.05 mass% or less, and zirconium of 0.1 mass% or more and 0.3 mass% or less. found.
Further, it was found that the laminated model 1 should have the above composition.

According to the alloy powder for laminated molding having the above composition, even if the crystal grains of the laminated molded product 1 of the Ni-based alloy produced by the laminated molding method become relatively fine, the grain boundaries can be strengthened, so that the high temperature creep strength can be improved. The creep ductility can be improved.
Similarly, according to the laminated model 1 having the above composition, even if the crystal grains of the laminated model 1 are relatively fine, the grain boundaries can be strengthened, so that the high temperature creep strength and the creep ductility can be improved.
Further, according to the alloy powder for laminated molding having the above composition, the grain boundary strength can be improved, so that it is not necessary to coarsen the crystal grains by heat treatment as in the case where the grain boundary strength is not improved. Therefore, the strength characteristics at a temperature lower than 500 ° C. can be improved, and the heat treatment temperature of the laminated model 1 can be relatively lowered.
As described above, although it has been found that zirconium is effective in improving high-temperature creep strength and creep ductility by strengthening grain boundaries by being present at grain boundaries, it is contained as described later. If the amount is too large, the local melting point at the grain boundary may be lowered, causing a decrease in strength. However, according to the alloy powder for laminated molding having the above composition, the grain boundary strength is improved by relatively increasing the content of zirconium. Therefore, as described above, the heat treatment temperature of the laminated molding 1 is relatively high. It can be lowered, and the above-mentioned problem of strength reduction is unlikely to occur.

FIG. 1 is a diagram showing the structure of a laminated model 1 of a Ni-based alloy manufactured by a layered manufacturing method using an alloy powder for layered manufacturing having the above composition after heat treatment. In the laminated model 1 shown in FIG. 1, the average crystal grain size is 0.3 mm. According to the additive manufacturing product 1 shown in FIG. 1, by manufacturing by the additive manufacturing method, it is possible to obtain finer crystal grains as compared with the conventional cast material. The average crystal grain size of the conventional cast material is on the order of mm.

FIG. 2 is a table showing the composition of the alloy powder for laminated molding according to some embodiments. Hereinafter, with reference to FIG. 2, the composition of the precipitate in the nickel-based alloy and each component of the alloy powder for laminated molding according to some embodiments will be described.

(About γ'phase)
The γ'phase is a precipitate mainly composed of Ni, Ti, Al and Ta. The γ'phase contributes to the strengthening of the material by finely dispersing and precipitating in the crystal grains during the heat treatment.

(About MC type carbide)
M in the MC type carbide is mainly composed of Ti, Ta, and Nb. The MC-type carbide is precipitated after the laminated molding.
The MC-type carbides are sparsely precipitated as coarse precipitates in the conventional cast material, but in the laminated model, fine MC-type carbides are dispersed and precipitated in the crystal grains due to quenching and solidification.
When fine MC-type carbides are dispersed and precipitated in the crystal grains, carbon is fixed by the MC-type carbides, so that M ₂₃ C ₆ -type carbides are less likely to precipitate on the crystal grain boundaries, and M ₂₃ C ₆ -type carbides are difficult to precipitate. The effect of strengthening the crystal grain boundaries is reduced. Therefore, it is necessary to reduce the precipitation of MC-type carbides as much as possible.
However, since Ti, Ta, and Nb are also constituent elements of the γ'phase, which is the strengthening phase of the matrix, it is necessary to add a certain amount.

(About M ₂₃ C ₆ type carbide)
M in M _{23 C6} type carbide is mainly composed of Cr, Ni and W.
M _{23 C6} type carbides increase grain boundary strength by precipitating at grain boundaries after aging heat treatment and suppress grain boundary rupture during creep deformation, resulting in improved creep ductility and brittle fracture against stress concentration. Can be prevented.

In the following description, when the content of each element is expressed as a percentage, unless otherwise specified, it is expressed as a mass%.

(Co: 15.0% or more and 25.0% or less)
Co is required to be 15.0% or more because it has an effect of increasing the limit (solid solution limit) for dissolving Ti, Al and the like in the matrix at a high temperature and promoting the solid solution of MC-type carbides.
If the amount of Co is more than 25.0%, a harmful phase is precipitated and brittle, and the high temperature strength is lowered. Therefore, it is necessary to make it 25.0% or less. Therefore, the Co content was set within the range of 15.0% or more and 25.0% or less.

(Cr: 10.0% or more and 25.0% or less)
If the amount of Cr is less than 10%, the high temperature oxidation resistance cannot be sufficiently improved by adding Cr. In addition, the amount of M ₂₃ C ₆ type carbide precipitated decreases and the high temperature strength decreases, so it is necessary to add 10% or more. On the other hand, if the amount of Cr exceeds 25%, a harmful phase is precipitated, which causes a decrease in strength and a decrease in ductility, which is not preferable. Therefore, the Cr content was set within the range of 10.0% or more and 25.0% or less.

(Mo: 0.0% or more and 3.5% or less)
Mo dissolves in the γ phase, which is a matrix, and is effective in improving the strength by strengthening the solid solution. However, if the amount of Mo is more than 3.5%, a harmful phase is precipitated, which causes a decrease in strength and a decrease in ductility. Therefore, the Mo content was set within the range of 0.0% or more and 3.5% or less.

(W: 0.5% or more and 10.0% or less)
W dissolves in the γ phase, which is a matrix, and is effective in improving the strength by strengthening the solid solution. In addition, it is a constituent element of M ₂₃ C ₆ type carbide and has the effect of suppressing the coarsening of M ₂₃ C ₆ type carbide, so it is necessary to add 0.5% or more. However, if the amount of W is more than 10.0%, a harmful phase is precipitated, which causes a decrease in strength and a decrease in ductility. Therefore, the W content was set within the range of 0.5% or more and 10.0% or less.

(Al: 1.0% or more and 4.0% or less)
Al is an element that produces a γ'phase, and is effective in enhancing the high temperature strength of the alloy, particularly the high temperature creep strength, and also in improving the oxidation resistance and corrosion resistance at high temperatures by strengthening the precipitation by the γ'phase precipitation particles. If the amount of Al is less than 1.0, the amount of precipitation of the γ'phase becomes small, and the precipitation strengthening by the precipitated particles cannot be sufficiently achieved. However, if the amount of Al exceeds 4.0%, the weldability is lowered and cracks frequently occur during laminated molding. Therefore, the Al content was set within the range of 1.0% or more and 4.0% or less.

(Ti: 0.0% or more and 5.0% or less)
Ti is an element that produces a γ'phase, and is effective in increasing the high temperature strength of the alloy, especially the high temperature creep strength, and also in improving the oxidation resistance and corrosion resistance at high temperatures by strengthening the precipitation by the γ'phase precipitation particles. If the amount of Ti exceeds 5.0%, the weldability is lowered and cracks frequently occur during laminated molding. Further, since the amount of MC-type carbide precipitated increases and carbon is immobilized, the amount of Ti needs to be suppressed to 5.0%. Therefore, the Ti content was set within the range of 0.0% or more and 5.0% or less.

(Ta: 0.0% or more and 4.0% or less)
Ta is an element that produces a γ'phase, and enhances the high temperature strength of the alloy, especially the high temperature creep strength, by strengthening the precipitation by the γ'phase precipitation particles. On the other hand, it is an element that produces MC-type carbide that is stable at high temperature in the crystal grains, and if it is added in excess of 4.0%, carbon will be immobilized. M ₂₃ C ₆ type carbides are no longer produced, the strength of grain boundaries is reduced, and brittle fracture is likely to occur. Therefore, the Ta content was set within the range of 0.0% or more and 4.0% or less.

(About the content of Al, Ti, and Ta)
As a result of diligent studies by the inventors, when the parameter for the aluminum content is Al mass%, the parameter for the titanium content is Ti mass%, and the parameter for the tantalum content is Ta mass%. , Al + 0.56 × Ti + 0.15 × Ta When the value calculated exceeds 4.0% by mass, it was found that the γ'phase strengthening works effectively and the high temperature creep strength is improved. Therefore, the contents of Al, Ti, and Ta may satisfy the above-mentioned formula (A).

(Nb: 0.0% or more and 2.0% or less)
Nb is an element that produces a γ'phase, and the high temperature strength of the alloy, particularly the high temperature creep strength, is enhanced by the precipitation strengthening by the γ'phase precipitation particles. On the other hand, it is an element that produces MC-type carbide that is stable at high temperature in the crystal grains, and if it is added in excess of 2.0%, carbon will be immobilized. M ₂₃ C ₆ type carbides are no longer produced, the strength of grain boundaries is reduced, and brittle fracture is likely to occur. Therefore, the content of Nb was set within the range of 0.0% or more and 2.0% or less.

(C: 0.03% or more and 0.2% or less)
C can strengthen the grain boundaries and improve creep ductility by forming carbides and precipitating them at the grain boundaries by an appropriate heat treatment. If the C content is less than 0.03%, the amount of carbide is too small and the strengthening effect cannot be expected. On the other hand, when the C content is more than 0.2%, the amount of MC-type carbides precipitated in the crystal grains increases, and the intra-grain strength becomes too large, so that the strength of the grain boundaries relatively decreases and brittleness occurs. Destruction is likely to occur. Therefore, the content of C was set within the range of 0.03% or more and 0.2% or less.

(B: 0.003% or more and 0.05% or less)
When B is present at the grain boundaries, it strengthens the grain boundaries and is effective in improving the high-temperature creep strength and creep ductility. When 0.003% or more is added, the grain boundary strengthening effect is increased. Further, when the content of B is 0.01% or more, the effect becomes larger. On the other hand, if the B content exceeds 0.05%, boride may be formed and the ductility may decrease. Therefore, the content of B was set within the range of 0.003% or more and 0.05% or less. Even within the above range, the content of B is particularly preferably 0.01% or more.

(Zr: 0.1% or more and 0.3% or less)
When Zr is present at the grain boundaries, it strengthens the grain boundaries and is effective in improving high-temperature creep strength and creep ductility. When the crystal grains are fine grains of 1.0 mm or less, Al + 0.56 × Ti + 0.15 × Ta is 4.0% or more, and the volume ratio of the γ'phase is 15% or more, the Zr content is 0. If it is less than 1%, the intergranular strength is relatively low as compared with the intragranular strength, and the ductility is lowered. On the other hand, if the Zr content exceeds 0.3%, the local melting point at the grain boundary may be lowered to cause a decrease in strength. Therefore, the Zr content was set within the range of 0.1% or more and 0.3% or less.

The rest of each of the above elements is Ni and unavoidable impurities. In addition, this kind of Ni-based alloy may contain Fe, Si, Mn, Cu, P, S, N and the like as unavoidable impurities, but these are for Fe, Si, Mn and Cu, respectively. It is desirable that it is 0.5% or less, and 0.01% or less for P, S, and N, respectively.

(About crystal grain size)
When the additive manufacturing product 1 is manufactured by the additive manufacturing method using the alloy powder for additive manufacturing according to some embodiments, the structure is locally formed by quenching and solidification, so that the crystal grain size is changed to 2. It can be less than 0 mm. Regarding the strength characteristics at a temperature lower than 500 ° C., the smaller the crystal grain size, the higher the strength tends to be. Therefore, the crystal grain size is preferably less than 2.0 mm. On the other hand, regarding the strength characteristics at a temperature higher than 700 ° C., particularly the creep strength, it is desirable that the crystal particle size is 0.3 mm or more because the life is shortened if the crystal particle size is small.
Therefore, in the laminated model 1 using the alloy powder for layered modeling according to some embodiments, the average particle size of the crystals is preferably 0.1 mm or more and less than 2.0 mm.
As a result, the strength of the laminated model 1 can be improved. By setting the average particle size of the crystals in the laminated model 1 to 0.3 mm or more and less than 2.0 mm, it is possible to improve the strength characteristics at a relatively high temperature, particularly the creep strength. Further, when the average particle size is less than 1.0 mm, the strength at a relatively low temperature can be improved.

(About the volume fraction of the γ'phase)
In the laminated model 1 using the alloy powder for layered modeling according to some embodiments, the volume fraction of the γ'phase is preferably 15% or more.
As a result, the high-temperature creep strength and creep ductility of the laminated model 1 can be improved.

(About examples)
Hereinafter, examples using the alloy powder for laminated modeling according to some embodiments will be described with reference to comparative examples.
FIG. 3 is a table showing the components, compositions, and high-temperature creep test results for Examples and Comparative Examples using the alloy powder for laminated molding according to some embodiments.
In Examples 1 to 4 and Comparative Examples 1 to 3 shown in FIG. 3, a nickel-based alloy powder (particle size 10 to 45 μm) having each component composition was produced by a gas atomizing method. Then, using the nickel-based alloy powder, laminated molding was performed on a base plate made of SUS316 by a metal laminated molding device (laser method, powder bed). As for the laminated molding conditions, the average solidification layer thickness per layer was 45 μm, the number of laminated layers was 2300, and the maximum thickness was about 100 mm.

After the laminated molding, a stress relieving heat treatment (heating at 1200 ° C. for 2 hours) was performed to separate the laminated model from the base plate. Then, after heating to 1250 ° C. for 2 hours as a solution heat treatment, heating to 1000 ° C. for 4 hours as a stabilizing heat treatment, and further heating at 850 ° C. for 8 hours as an aging heat treatment.
For each laminated model after the aging heat treatment, a round bar-shaped smoothing test piece for a creep rupture test was cut out and subjected to a high temperature creep rupture test at a temperature of 760 ° C. and a load force of 490 MPa in accordance with the high temperature creep test method of JISZ 2272. ..

The results of examining the values of creep rupture elongation obtained by the above-mentioned high-temperature creep test at 760 ° C. are as shown in the table of FIG.
In Examples 1 to 4 shown in FIG. 3, the creep rupture elongation of each of the laminated shaped bodies is 3% or more. In Comparative Examples 1 to 3 shown in FIG. 3, the creep rupture elongation is less than 3%, which is small.
If the creep rupture elongation is smaller than 3%, it is likely to break brittlely mainly in the stress concentration portion, and the allowable design stress is significantly reduced. Therefore, the creep rupture elongation needs to be 3% or more. In that respect, in Examples 1 to 4 shown in FIG. 3, since the creep rupture elongation of each of the laminated shaped bodies is 3% or more, the allowable stress can be increased as compared with Comparative Examples 1 to 3. ..

(About the manufacturing method of laminated model 1)
FIG. 4 is a flowchart showing a manufacturing procedure of a laminated model (laminated model) 1 using the alloy powder for layered modeling according to some embodiments.
As shown in FIG. 4, the procedure for manufacturing the laminated model 1 using the alloy powder for layered modeling according to some embodiments includes a step S10 for laminating modeling and a step S20 for performing heat treatment.

(Step S10 for laminated modeling)
In the manufacturing procedure of the laminated molding 1 using the alloy powder for laminated molding according to some embodiments, the step S10 for laminating molding is laminated by the laminated molding using the alloy powder for laminated molding according to some embodiments. This is the process of forming a model. That is, the laminated modeling method according to some embodiments includes a step of forming a laminated model by laminating modeling using the alloy powder for laminating modeling according to some embodiments.

In step S10 for laminating and modeling according to some embodiments, the laminated model 1 is laminated and modeled by a three-dimensional laminated modeling device (not shown). The three-dimensional laminated modeling apparatus (not shown) can manufacture the three-dimensional laminated model 1 by irradiating the above-mentioned alloy powder for laminated modeling, which is the raw material powder, with an energy beam to perform the laminated modeling. .. The three-dimensional laminated molding apparatus (not shown) may be, for example, an apparatus that performs laminated molding by a powder bed method, or may be, for example, an apparatus that performs laminated molding by an LMD (Laser Metal Deposition) method.

According to the laminated modeling method according to some embodiments, even if the crystal grains become relatively fine in the laminated model (laminated model 1) obtained by going through the above step (step S10 for layering). Since the grain boundaries can be strengthened, high temperature creep strength can be improved and creep ductility can be improved.

(Step S20 for heat treatment)
In the manufacturing procedure of the laminated molding 1 using the alloy powder for laminated molding according to some embodiments, the step S20 to perform the heat treatment is laminated using the alloy powder for laminated molding according to some embodiments. This is a step of heat-treating a laminated model. That is, in step S20 for performing the heat treatment according to some embodiments, it is a step of performing heat treatment on the laminated model 1 which has been laminated and modeled in step S10 for laminating modeling.

FIG. 5 is a flowchart for explaining the heat treatment in step S20 in which the heat treatment according to some embodiments is performed. The steps S20 for performing the heat treatment according to some embodiments are, for example, a step S21 for performing the first heat treatment, a step S22 for performing the second heat treatment, a step S23 for performing the third heat treatment, and a step S24 for performing the fourth heat treatment. And include.

For example, step S21 in which the first heat treatment is performed is for removing stress so that the laminated model 1 formed by using the alloy powder for layered modeling according to some embodiments is not deformed by the residual stress at the time of modeling. This is a step of performing stress relief heat treatment.
For example, in step S21 in which the first heat treatment according to one embodiment is performed, the laminated model 1 may be heated to 1200 ° C. and held for 2 hours.
As a result, it is possible to suppress deformation of the laminated model 1 formed by using the alloy powder for laminated modeling according to some embodiments due to residual stress during modeling.

For example, step S22 of performing the second heat treatment is a step of performing solution heat treatment of the laminated model 1. In step S22 in which the second heat treatment according to some embodiments is performed, it is preferable to perform a solution heat treatment in which the laminated model 1 is held at a temperature of 1150 ° C. or higher and 1270 ° C. or lower for 0.5 hours or longer and 10 hours or shorter.
For example, in step S22 in which the second heat treatment according to one embodiment is performed, the laminated model 1 may be heated to 1250 ° C. and held for 2 hours.
As a result, the coarsening of the crystal grains progresses, so that the average particle size of the crystals can be made 0.1 mm or more. If the heating temperature in the second heat treatment is higher than 1270 ° C., not only the average particle size of the crystals becomes larger than 2.0 mm, but also the temperature is close to the melting point, so that partial melting may occur. Therefore, the temperature should be 1270 ° C. or lower.

For example, step S23 for performing the third heat treatment is a step for performing a stabilized heat treatment for the laminated model 1. In step S23 in which the third heat treatment according to some embodiments is performed, it is preferable to perform a stabilized heat treatment in which the laminated model 1 is held at a temperature of 900 ° C. or higher and 1150 ° C. or lower for 0.5 hours or longer and 10 hours or shorter.
For example, in step S23 in which the third heat treatment according to one embodiment is performed, the laminated model 1 may be heated to 1000 ° C. and held for 4 hours.
As a result, the γ'phase having a precipitation strengthening effect is precipitated in the crystal grains, and the material strength can be improved.

For example, the step S24 of performing the fourth heat treatment is a step of performing the aging heat treatment of the laminated model 1. In step S24 in which the fourth heat treatment according to some embodiments is performed, it is preferable to perform an aging heat treatment in which the laminated model 1 is held at a temperature of 750 ° C. or higher and 900 ° C. or lower for 0.5 hours or longer and 30 hours or shorter.
For example, in step S24 in which the fourth heat treatment according to one embodiment is performed, the laminated model 1 may be heated to 850 ° C. and held for 8 hours.
As a result, finer γ'phases are precipitated in the crystal grains than those obtained by the third heat treatment, and the material strength can be improved. Further, since the grain boundary strength can be improved by precipitating M ₂₃ C ₆ type carbides at the crystal grain boundaries, there is an effect of improving creep ductility.

According to the laminated molding method according to some embodiments, the laminated molding 1 in which the high temperature creep strength is improved and the creep ductility is improved by passing through the above-mentioned heat treatment step (heat treatment step S20) is obtained. can get.

The present disclosure is not limited to the above-described embodiment, and includes a modified form of the above-described embodiment and a combination of these embodiments as appropriate.

The contents described in each of the above embodiments are grasped as follows, for example.
(1) The alloy powder for laminated molding according to at least one embodiment of the present disclosure is an alloy powder for laminated molding composed of a nickel-based alloy, and is composed of 15.0% by mass or more and 25.0% by mass or less of cobalt. , 10.0% by mass or more and 25.0% by mass or less of chromium, 0.0% by mass or more and 3.5% by mass or less of molybdenum, 0.5% by mass or more and 10.0% by mass or less of tungsten, 1 0.0% by mass or more and 4.0% by mass or less of aluminum, 0.0% by mass or more and 5.0% by mass or less of titanium, 0.0% by mass or more and 4.0% by mass or less of tantalum, 0.0 Niobium of mass% or more and 2.0 mass% or less, carbon of 0.03 mass% or more and 0.2 mass% or less, boron of 0.003 mass% or more and 0.05 mass% or less, 0.1 mass% Contains zirconium of 0.3% by mass or more and less than 0.3% by mass.

As described above, as a result of diligent studies by the inventors, boron is effective in improving high-temperature creep strength and creep ductility by strengthening grain boundaries by being present at grain boundaries, and is added in an amount of 0.003% by mass or more. It was found that the effect of strengthening the grain boundaries was increased by doing so. On the other hand, it was found that if the addition amount exceeds 0.03% by mass, boride may be formed and the ductility may be lowered.
Further, as described above, as a result of diligent studies by the inventors, it was found that zirconium is effective in improving high temperature creep strength and creep ductility by strengthening grain boundaries by being present at grain boundaries. There is. When the crystal grains are fine particles of, for example, 2.0 mm or less, satisfy the following formula (A), and the volume ratio of the γ'phase is 15% or more, the amount of zirconium added is less than 0.1% by mass. The grain boundary strength is relatively low as compared with the intragranular strength, and the ductility is lowered. On the other hand, if the amount of zirconium added exceeds 0.3% by mass, the local melting point at the grain boundary may be lowered to cause a decrease in strength.
The above-mentioned formula (A) is expressed as follows. When the parameter for the aluminum content is Al mass%, the parameter for the titanium content is Ti mass%, and the parameter for the tantalum content is Ta mass%, the formula (A) is as follows. Is.
Al + 0.56 x Ti + 0.15 x Ta> 4.0 ... (A)

According to the configuration of (1) above, even if the crystal grains of the laminated model 1 of the Ni-based alloy produced by the laminated modeling method become relatively fine, the grain boundaries can be strengthened, so that the high temperature creep strength is improved and the creep ductility is improved. You can improve it.

(2) In some embodiments, in the configuration of (1) above, 0.01% by mass or more and 0.05% by mass or less of boron is contained.

As described above, as a result of diligent studies by the inventors, it was found that the grain boundary strengthening effect is further improved when the amount of boron added is 0.01% by mass or more and 0.05% by mass or less.
Therefore, according to the configuration of (2) above, the high temperature creep strength can be further improved and the creep ductility can be further improved.

(3) In some embodiments, in the configuration of (1) or (2) above, the parameter for aluminum content is Al mass%, the parameter for titanium content is Ti mass%, and tantalum. When the parameter for the content is Ta mass%,
Equation (A):
Al + 0.56 x Ti + 0.15 x Ta> 4.0
Satisfy the relational expression represented by.

As described above, by satisfying the formula (A), the high-temperature creep of the laminated molded product 1 of the Ni-based alloy produced by the laminated molding method using the alloy powder for laminated molding in the configurations (1) and (2) above. Strength can be improved and creep ductility can be improved.

(4) The laminated model according to at least one embodiment of the present disclosure is a laminated model composed of a nickel-based alloy, which comprises 15.0% by mass or more and 25.0% by mass or less of cobalt and 10.0 by mass. Chromium of mass% or more and 25.0 mass% or less, molybdenum of 0.0 mass% or more and 3.5 mass% or less, tungsten of 0.5 mass% or more and 10.0 mass% or less, 1.0 mass% Aluminum of 4.0% by mass or more, titanium of 0.0% by mass or more and 5.0% by mass or less, tantalum of 0.0% by mass or more and 4.0% by mass or less, and 0.0% by mass or more 2 Niob of 0.0% by mass or less, carbon of 0.03% by mass or more and 0.2% by mass or less, boron of 0.003% by mass or more and 0.05% by mass or less, and 0.1% by mass or more and 0.3. Contains zirconium of mass% or less.

According to the configuration of (4) above, as in the configuration of (1) above, even if the crystal grains of the laminated model are relatively fine, the grain boundaries can be strengthened, so that the high temperature creep strength is improved and the creep ductility is improved. Can be planned.

(5) In some embodiments, in the configuration of (4) above, 0.01% by mass or more and 0.05% by mass or less of boron is contained.

According to the configuration of (5) above, similarly to the configuration of (2) above, the high temperature creep strength of the laminated model can be further improved, and the creep ductility can be further improved.

(6) In some embodiments, in the configuration of (4) or (5) above, the parameter for aluminum content is Al mass%, the parameter for titanium content is Ti mass%, and tantalum. When the parameter for the content is Ta mass%,
Equation (A):
Al + 0.56 x Ti + 0.15 x Ta> 4.0
Satisfy the relational expression represented by.

According to the configuration of the above (6), as described above, by satisfying the formula (A), the high temperature creep strength and the creep ductility of the laminated model in the configurations of the above (4) and (5) can be improved.

(7) In some embodiments, in any of the configurations (4) to (6) above, the average particle size of the crystals is 0.1 mm or more and less than 1.0 mm.

According to the configuration of (7) above, as described above, by setting the average particle size of the crystals to 0.1 mm or more and less than 2.0 mm, the laminated molding in any of the configurations (4) to (6) above. You can improve your body strength.

(8) In some embodiments, the volume fraction of the gamma prime phase is 15% or more in any of the configurations (4) to (7) above.

According to the configuration of (8) above, as described above, by setting the volume fraction of the gamma prime phase to 15% or more, high-temperature creep of the laminated model in any of the configurations (4) to (7) above. Strength can be improved and creep ductility can be improved.

(9) The laminated molding method according to at least one embodiment of the present disclosure is a laminated molding body (laminated model 1) by laminating molding using an alloy powder for laminating molding having any of the above configurations (1) to (3). (Step S10 for laminating modeling) is provided.

According to the method (9) above, in the laminated model (laminated model 1) obtained through the above steps, even if the crystal grains are relatively fine, the grain boundaries can be strengthened, so that the high temperature creep strength can be obtained. It can be improved and creep ductility can be improved.

(10) In some embodiments, in the method of (9) above, the laminated model (laminated model 1) formed in the step of forming the laminated model (laminated model 1) (step S10 for layering). ) May further include a step of performing the heat treatment (step S20 of performing the heat treatment).

According to the method (10) above, a laminated model (laminated model 1) having improved high-temperature creep strength and improved creep ductility can be obtained.

(11) In some embodiments, in the method of (10) above, in the step of performing the heat treatment (step S20 of performing the heat treatment), the laminated model (laminated model 1) is placed at a temperature of 1150 ° C. or higher and 1270 ° C. or lower. The step of performing the solution heat treatment (step S22 of performing the second heat treatment) of holding for 0.5 hours or more and 10 hours or less may be included.

According to the method (11) above, the coarsening of the crystal grains progresses, so that the average particle size of the crystals can be made 0.1 mm or more.

(12) In some embodiments, in the method (10) or (11) above, in the step of performing the heat treatment (step S20 of performing the heat treatment), the laminated model (laminated model 1) is heated to 900 ° C. or higher and 1150 ° C. The step of performing the stabilization heat treatment (step S23 of performing the third heat treatment) of holding at the following temperature for 0.5 hours or more and 10 hours or less may be included.

According to the method (12) above, the γ'phase having a precipitation strengthening effect is precipitated in the crystal grains, and the material strength can be improved.

(13) In some embodiments, in any of the methods (10) to (12) above, in the step of performing the heat treatment (step S20 of performing the heat treatment), the laminated model (laminated model 1) is heated to 750 ° C. The step of performing the aging heat treatment (step S24 for performing the fourth heat treatment) of holding at a temperature of 900 ° C. or lower for 0.5 hours or more and 30 hours or less may be included.

According to the method (13) above, finer γ'phases are precipitated in the crystal grains than those according to the method (12) above, and the material strength can be improved. Further, since the grain boundary strength can be improved by precipitating M ₂₃ C ₆ type carbides at the crystal grain boundaries, there is an effect of improving creep ductility.

1 Laminated model (laminated model)

Claims (13)

An alloy powder for laminated molding composed of a nickel-based alloy.
Cobalt of 15.0% by mass or more and 25.0% by mass or less,
With 10.0% by mass or more and 25.0% by mass or less of chromium,
With molybdenum of 0.0% by mass or more and 3.5% by mass or less,
Tungsten of 0.5% by mass or more and 10.0% by mass or less,
Aluminum of 1.0% by mass or more and 4.0% by mass or less,
With titanium of 0.0% by mass or more and 5.0% by mass or less,
With tantalum of 0.0% by mass or more and 4.0% by mass or less,
Niobium of 0.0% by mass or more and 2.0% by mass or less,
With carbon of 0.03% by mass or more and 0.2% by mass or less,
With boron of 0.003% by mass or more and 0.05% by mass or less,
Zirconium of 0.1% by mass or more and 0.3% by mass or less,
Alloy powder for laminated modeling containing. The alloy powder for laminated molding according to claim 1, which contains 0.01% by mass or more and 0.05% by mass or less of boron. The parameter for aluminum content is Al mass%.
The parameter for titanium content is Ti mass%.
When the parameter for the tantalum content is Ta mass%,
Equation (A):
Al + 0.56 x Ti + 0.15 x Ta> 4.0
The alloy powder for laminated molding according to claim 1 or 2, which satisfies the relational expression represented by. It is a laminated model made of nickel-based alloy.
Cobalt of 15.0% by mass or more and 25.0% by mass or less,
With 10.0% by mass or more and 25.0% by mass or less of chromium,
With molybdenum of 0.0% by mass or more and 3.5% by mass or less,
Tungsten of 0.5% by mass or more and 10.0% by mass or less,
Aluminum of 1.0% by mass or more and 4.0% by mass or less,
With titanium of 0.0% by mass or more and 5.0% by mass or less,
With tantalum of 0.0% by mass or more and 4.0% by mass or less,
Niobium of 0.0% by mass or more and 2.0% by mass or less,
With carbon of 0.03% by mass or more and 0.2% by mass or less,
With boron of 0.003% by mass or more and 0.05% by mass or less,
Zirconium of 0.1% by mass or more and 0.3% by mass or less,
Laminated model containing. The laminated model according to claim 4, which contains 0.01% by mass or more and 0.05% by mass or less of boron. The parameter for aluminum content is Al mass%.
The parameter for titanium content is Ti mass%.
When the parameter for the tantalum content is Ta mass%,
Equation (A):
Al + 0.56 x Ti + 0.15 x Ta> 4.0
The laminated model according to claim 4 or 5, which satisfies the relational expression represented by. The laminated model according to any one of claims 4 to 6, wherein the average particle size of the crystals is 0.1 mm or more and less than 2.0 mm. The laminated model according to any one of claims 4 to 7, wherein the volume fraction of the gamma prime phase is 15% or more. A laminated modeling method comprising a step of forming a laminated model by laminating modeling using the alloy powder for laminating modeling according to any one of claims 1 to 3. The laminated modeling method according to claim 9, further comprising a step of heat-treating the laminated model formed in the step of forming the laminated model. The laminated molding method according to claim 10, wherein the step of performing the heat treatment includes a step of performing a solution heat treatment in which the laminated model is held at a temperature of 1150 ° C. or higher and 1270 ° C. or lower for 0.5 hours or more and 10 hours or less. .. The lamination according to claim 10 or 11, wherein the step of performing the heat treatment includes a step of performing a stabilization heat treatment in which the laminated model is held at a temperature of 900 ° C. or higher and 1150 ° C. or lower for 0.5 hours or more and 10 hours or less. Modeling method. The step of performing the heat treatment is any one of claims 10 to 12, which includes a step of performing an aging heat treatment in which the laminated model is held at a temperature of 750 ° C. or higher and 900 ° C. or lower for 0.5 hours or more and 30 hours or less. The laminated molding method described in.

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