JP2024094761A - Ni-based self-fluxing alloy - Google Patents

Abstract

To provide a Ni-based alloy capable of obtaining a film 6 excellent in fluxibility and toughness.SOLUTION: The Ni-based self-fluxing alloy for a film 6 contains P: 0.10 mass% or more and 10.00 mass% or less, B: 0.00 mass% or more and 5.00 mass% or less, Si: 0.00 mass% or more and 5.00 mass% or less, C: 0.0 mass% or more and 3.0 mass% or less, Cr: 0.0 mass% or more and 30.0 mass% or less, Cu: 0.0 mass% or more and 10.0 mass% or less, Mn: 0.0 mass% or more and 10.0 mass% or less, Fe: 0.0 mass% or more and 10.0 mass% or less, and Co: 0.0 mass% or more and 10.0 mass% or less. The alloy may further comprise Mo, W, Al, Ti, Zr, and Hf. The ratio R1 calculated by the following formula (3) is 7.00 or less. R1=(B%+Si%)/P% (3)SELECTED DRAWING: Figure 1

Description

This specification discloses an alloy having self-fluxing properties. In particular, this specification discloses a self-fluxing alloy in which the base metal is Ni.

Various Ni-based self-fluxing alloys are specified in "JIS H8303 2010". Each Ni-based self-fluxing alloy contains B and Si. B and Si reduce oxides. B and Si can also lower the solidus or liquidus temperature of the alloy. This Ni-based self-fluxing alloy is subjected to a thermal spraying method, build-up welding method, centrifugal casting method, etc. to obtain a coating. The main part of the metal product is covered with this coating. This metal product has excellent corrosion resistance, wear resistance, etc.

The coating may be subjected to a remelting process. In the remelting process, the coating is heated and a liquid phase appears in the coating. This liquid phase solidifies upon cooling. The remelting process may increase the density of the coating. Ni-based self-fluxing alloys are suitable for the remelting process because of their low solidus or liquidus temperatures.

JIS Handbook 2010 H8303

The formation of the coating and the subsequent remelting process expose the main part to high temperatures. This thermal history causes damage to the main part. This thermal history also deteriorates the properties of the metal product. The self-fluxing properties of conventional alloys are insufficient.

When metal products are used in harsh environments, the coating is easily damaged. To prevent damage, the coating must be tough. The toughness of coatings obtained from conventional alloys is insufficient.

The inventors' intention is to provide a Ni-based alloy that has excellent self-fluxing properties and can produce a coating with excellent toughness.

The Ni-based self-fluxing alloy disclosed in this specification is
P: 0.10% by mass or more and 10.00% by mass or less,
B: 0.00% by mass or more and 5.00% by mass or less,
Si: 0.00% or more and 5.00% or less by mass,
C: 0.0% by mass or more and 3.0% by mass or less,
Cr: 0.0% by mass or more and 30.0% by mass or less,
Mo: 0.0% by mass or more and 9.0% by mass or less,
W: 0.0% by mass or more and 18.0% by mass or less,
Cu: 0.0% by mass or more and 10.0% by mass or less,
Mn: 0.0% by mass or more and 10.0% by mass or less,
Fe: 0.0% by mass or more and 10.0% by mass or less,
Co: 0.0% by mass or more and 10.0% by mass or less,
Al: 0.00% by mass or more and 0.20% by mass or less,
Ti: 0.00% by mass or more and 0.20% by mass or less,
Zr: 0.00% by mass or more and 0.20% by mass or less,
and Hf: 0.00% by mass or more and 0.20% by mass or less, with the balance being Ni and unavoidable impurities. This alloy satisfies the following formulas (1) and (2). The ratio R1 calculated by the following formula (3) is 7.00 or less.
Mo% + W% / 2 ≦ 9.0 (1)
Al% + Ti% + Zr% + Hf% ≦ 0.20 (2)
R1 = (B% + Si%) / P% (3)
In these formulas, Mo% represents the mass content of Mo, W% represents the mass content of W, Al% represents the mass content of Al, Ti% represents the mass content of Ti, Zr% represents the mass content of Zr, Hf% represents the mass content of Hf, B% represents the mass content of B, Si% represents the mass content of Si, and P% represents the mass content of P.

Preferably, the alloy is substantially free of B. Preferably, the alloy is substantially free of Si.

The powder material disclosed in this specification is a Ni-based self-fluxing alloy.
P: 0.10% by mass or more and 10.00% by mass or less,
B: 0.00% by mass or more and 5.00% by mass or less,
Si: 0.00% or more and 5.00% or less by mass,
C: 0.0% by mass or more and 3.0% by mass or less,
Cr: 0.0% by mass or more and 30.0% by mass or less,
Mo: 0.0% by mass or more and 9.0% by mass or less,
W: 0.0% by mass or more and 18.0% by mass or less,
Cu: 0.0% by mass or more and 10.0% by mass or less,
Mn: 0.0% by mass or more and 10.0% by mass or less,
Fe: 0.0% by mass or more and 10.0% by mass or less,
Co: 0.0% by mass or more and 10.0% by mass or less,
Al: 0.00% by mass or more and 0.20% by mass or less,
Ti: 0.00% by mass or more and 0.20% by mass or less,
Zr: 0.00% by mass or more and 0.20% by mass or less,
and Hf: 0.00% by mass or more and 0.20% by mass or less, with the balance being Ni and unavoidable impurities. This alloy satisfies the following formulas (1) and (2). A ratio R1 calculated by the following formula (3) is 7.00 or less.
Mo% + W% / 2 ≦ 9.0 (1)
Al% + Ti% + Zr% + Hf% ≦ 0.20 (2)
R1 = (B% + Si%) / P% (3)
In these formulas, Mo% represents the mass content of Mo, W% represents the mass content of W, Al% represents the mass content of Al, Ti% represents the mass content of Ti, Zr% represents the mass content of Zr, Hf% represents the mass content of Hf, B% represents the mass content of B, Si% represents the mass content of Si, and P% represents the mass content of P.

The material of the coating disclosed in this specification is a Ni-based self-fluxing alloy.
P: 0.10% by mass or more and 10.00% by mass or less,
B: 0.00% by mass or more and 5.00% by mass or less,
Si: 0.00% or more and 5.00% or less by mass,
C: 0.0% by mass or more and 3.0% by mass or less,
Cr: 0.0% by mass or more and 30.0% by mass or less,
Mo: 0.0% by mass or more and 9.0% by mass or less,
W: 0.0% by mass or more and 18.0% by mass or less,
Cu: 0.0% by mass or more and 10.0% by mass or less,
Mn: 0.0% by mass or more and 10.0% by mass or less,
Fe: 0.0% by mass or more and 10.0% by mass or less,
Co: 0.0% by mass or more and 10.0% by mass or less,
Al: 0.00% by mass or more and 0.20% by mass or less,
Ti: 0.00% by mass or more and 0.20% by mass or less,
Zr: 0.00% by mass or more and 0.20% by mass or less,
and Hf: 0.00% by mass or more and 0.20% by mass or less, with the balance being Ni and unavoidable impurities. This alloy satisfies the following formulas (1) and (2). A ratio R1 calculated by the following formula (3) is 7.00 or less.
Mo% + W% / 2 ≦ 9.0 (1)
Al% + Ti% + Zr% + Hf% ≦ 0.20 (2)
R1 = (B% + Si%) / P% (3)
In these formulas, Mo% represents the mass content of Mo, W% represents the mass content of W, Al% represents the mass content of Al, Ti% represents the mass content of Ti, Zr% represents the mass content of Zr, Hf% represents the mass content of Hf, B% represents the mass content of B, Si% represents the mass content of Si, and P% represents the mass content of P.

The metallic material disclosed in this specification has a main part and a coating covering the surface of the main part. The material of the coating is a Ni-based self-fluxing alloy. The Ni-based self-fluxing alloy is
P: 0.10% by mass or more and 10.00% by mass or less,
B: 0.00% by mass or more and 5.00% by mass or less,
Si: 0.00% or more and 5.00% or less by mass,
C: 0.0% by mass or more and 3.0% by mass or less,
Cr: 0.0% by mass or more and 30.0% by mass or less,
Mo: 0.0% by mass or more and 9.0% by mass or less,
W: 0.0% by mass or more and 18.0% by mass or less,
Cu: 0.0% by mass or more and 10.0% by mass or less,
Mn: 0.0% by mass or more and 10.0% by mass or less,
Fe: 0.0% by mass or more and 10.0% by mass or less,
Co: 0.0% by mass or more and 10.0% by mass or less,
Al: 0.00% by mass or more and 0.20% by mass or less,
Ti: 0.00% by mass or more and 0.20% by mass or less,
Zr: 0.00% by mass or more and 0.20% by mass or less,
and Hf: 0.00% by mass or more and 0.20% by mass or less, with the balance being Ni and unavoidable impurities. This alloy satisfies the following formulas (1) and (2). A ratio R1 calculated by the following formula (3) is 7.00 or less.
Mo% + W% / 2 ≦ 9.0 (1)
Al% + Ti% + Zr% + Hf% ≦ 0.20 (2)
R1 = (B% + Si%) / P% (3)
In these formulas, Mo% represents the mass content of Mo, W% represents the mass content of W, Al% represents the mass content of Al, Ti% represents the mass content of Ti, Zr% represents the mass content of Zr, Hf% represents the mass content of Hf, B% represents the mass content of B, Si% represents the mass content of Si, and P% represents the mass content of P.

The solidus or liquidus temperature of this Ni-based self-fluxing alloy is low. A dense coating can be formed from this Ni-based self-fluxing alloy by processing at a relatively low temperature. In this processing, the main part is not exposed to high temperatures. This coating has low hardness and excellent toughness. Metal products having this coating have excellent performance.

FIG. 1 is a cross-sectional view showing a schematic view of a part of a metal product according to one embodiment.

A preferred embodiment will be described below with reference to the drawings as appropriate.

The metal product 2 shown in FIG. 1 has a main part 4 and a coating 6. The coating 6 covers the surface of the main part 4. The coating 6 may cover the entire surface of the main part 4, or may cover only a part of it. The material of the main part 4 is a metallic material. Various metallic materials are suitable for the main part 4. Typical metallic materials are Fe-based alloys and Cu-based alloys. The coating 6 can be obtained by a thermal spraying method, a build-up welding method, a centrifugal casting method, or the like. In these methods, powder is used.

This powder is an aggregate of many particles. The material of these particles is a Ni-based self-fluxing alloy. This Ni-based self-fluxing alloy is,
P: 0.10% by mass or more and 10.00% by mass or less,
B: 0.00% by mass or more and 5.00% by mass or less,
Si: 0.00% or more and 5.00% or less by mass,
C: 0.0% by mass or more and 3.0% by mass or less,
Cr: 0.0% by mass or more and 30.0% by mass or less,
Mo: 0.0% by mass or more and 9.0% by mass or less,
W: 0.0% by mass or more and 18.0% by mass or less,
Cu: 0.0% by mass or more and 10.0% by mass or less,
Mn: 0.0% by mass or more and 10.0% by mass or less,
Fe: 0.0% by mass or more and 10.0% by mass or less,
Co: 0.0% by mass or more and 10.0% by mass or less,
Al: 0.00% by mass or more and 0.20% by mass or less,
Ti: 0.00% by mass or more and 0.20% by mass or less,
Zr: 0.00% by mass or more and 0.20% by mass or less,
and Hf: 0.00 mass % or more and 0.20 mass % or less, with the balance being Ni and unavoidable impurities.

In conventional Ni-based self-fluxing alloys, B and Si contribute to self-fluxing. In the Ni-based self-fluxing alloy of this embodiment, P mainly contributes to self-fluxing. This alloy has extremely excellent self-fluxing properties. The composition of this Ni-based self-fluxing alloy is described in detail below.

[Phosphorus (P)]
P plays an important role in the alloy according to the present embodiment. P lowers the solidus temperature. The addition of P can achieve a low solidus temperature that could not be achieved with conventional Ni-based self-fluxing alloys. The addition of P can achieve a dense coating 6 even in the case of remelting treatment under conditions of 1000°C or less, or even 950°C or less. The solidus temperature in the binary equilibrium diagram of Ni and B is about 1093°C. The solidus temperature in the binary equilibrium diagram of Ni and Si is about 1143°C. On the other hand, the solidus temperature in the binary equilibrium diagram of Ni and P is about 870°C, which is significantly low. It is speculated that such characteristics of P relative to Ni contribute to the low solidus temperature of the Ni-based self-fluxing alloy according to the present embodiment.

In the metal product 2, not only the characteristics of the coating 6 but also the characteristics of the substrate underneath are important. Usually, stainless steel base material is used for components that require high high-temperature strength and corrosion resistance, but when remelting treatment is performed at 1000°C or higher, which is necessary to densify the coating, the crystal grains of the stainless steel substrate become coarse and the strength decreases. In addition, Cu alloy base material is used for components that require high thermal conductivity and electrical conductivity, but the melting point of Cu is about 1083°C, and problems such as melting or excessive deformation of the substrate occur when remelting treatment is performed at 1000°C or higher. On the other hand, the coating 6 can be formed from this Ni-based self-fluxing alloy at a low treatment temperature. Furthermore, a remelting treatment at a low temperature can be adopted for this coating 6. Therefore, in this metal product 2, damage to the main part 4 due to thermal history can be suppressed. For example, when the material of the main part 4 is stainless steel, coarsening of the crystal grains is suppressed. Fine crystal grains can contribute to the strength of the metal product 2. If the material of the main part 4 is a copper alloy, melting and deformation of the main part 4 can be suppressed.

Furthermore, stainless steel conducts heat about three times slower than general steel materials (SS400), so it is prone to deformation when there is uneven heating, such as due to the shape of the base material or fusing with a gas burner. On the other hand, the solidus temperature of this Ni-based self-fluxing alloy is low, so the remelting process can be achieved even with a high-output heating means. In the remelting process using this heating means, uneven heating is unlikely to occur. Therefore, deformation of the main part 4 caused by uneven heating can be suppressed. This coating 6 is also suitable for the main part 4 with low thermal conductivity. Stainless steel is an example of a material for the main part 4 with low thermal conductivity.

In the conventional coating 6 made of a Ni-based self-fluxing alloy, B may diffuse from the coating 6 to the main part 4, impairing the properties of the metal product 2. For example, hard and coarse borides may crystallize, impairing the adhesion between the substrate and the coating, and thus deteriorating the corrosion resistance. In particular, when the material of the main part 4 is an Fe-based alloy, the properties of the metal product 2 are likely to be impaired. For example, when the material of the main part 4 is SUS304 (austenitic stainless steel), B that diffuses excessively to the grain boundaries of the main part 4 reacts with Cr to generate chromium borides. This generation reduces the Cr concentration in the surrounding SUS304 matrix, and a phenomenon similar to the so-called sensitization of stainless steel is observed, impairing the corrosion resistance of the main part 4 near the interface with the coating 6. When the material of the main part 4 is SUS316 (Mo-containing austenitic stainless steel), B that diffuses excessively to the grain boundaries of the main part 4 reacts with Cr and Mo to generate chromium borides and molybdenum borides. The generation of these compounds causes a shortage of Cr and Mo in the base of the main part 4, and the corrosion resistance of the main part 4 near the interface with the coating 6 is impaired. The inventors of the present invention clarified the cause of the corrosion resistance impairment in conventional Ni-based self-fluxing alloys by observing the microstructure of the interface between the main part 4 and the coating 6. Then, they conducted extensive research to suppress the corrosion resistance impairment, and arrived at a Ni-based self-fluxing alloy in which all or part of B is replaced with P. In this alloy, P diffuses into the main part 4. It is presumed that the diffusion of P suppresses the diffusion of B. In the main part 4 in which the diffusion of B is suppressed, corrosion resistance impairment is less likely to occur.

The coating 6 can be formed by a thermal spraying method using powder. Because the Ni-based self-fluxing alloy contains P, the coating 6 is dense. The reason for this is presumably as follows. In the thermal spraying method, high-temperature particles (molten metal) fly through space. During this flight, oxides are generated on the particles, although only slightly. Because the Ni-based self-fluxing alloy contains P, some of the oxides generated on the particles contain P. Because the sublimation temperature of the P-containing oxide is low, some of the P-containing oxide vaporizes during flight. Therefore, the amount of oxides contained in the coating 6 is small. In this coating 6, the inhibition of denseness caused by oxides is suppressed.

From these viewpoints, the P content is preferably 0.10 mass% or more, more preferably 0.20 mass% or more, and particularly preferably 0.50 mass% or more. Excess P leads to the precipitation of coarse phosphides in the coating 6. The coarse phosphides lead to embrittlement of the coating 6 and inhibit the machinability of the coating 6. From the viewpoints of the toughness and machinability of the coating 6, this content is preferably 10.00 mass% or less, more preferably 7.00 mass% or less, and particularly preferably 5.00 mass% or less.

[Boron (B)]
B lowers the solidus temperature of the Ni-based self-fluxing alloy. Furthermore, B can reduce oxides in the coating 6. On the other hand, excessive B leads to the precipitation of coarse borides in the coating 6. The coarse borides increase the liquidus temperature of the coating 6, making the remelting treatment of the coating 6 difficult. Furthermore, the coating 6 containing these borides has high hardness and poor toughness. From the viewpoint of ease of remelting treatment and excellent toughness of the coating 6, the content of B is preferably 5.00 mass% or less, more preferably 4.00 mass% or less, and particularly preferably 2.00 mass% or less.

In this Ni-based self-fluxing alloy, P plays a role in lowering the solidus temperature. Therefore, B is not an essential element. From the viewpoint of ease of remelting processing and excellent toughness of the coating 6, it is preferable that this alloy does not substantially contain B. In other words, an alloy in which the B content is below the detection limit and an alloy in which B is detected as an unavoidable impurity are preferable.

[Silicon (Si)]
Si lowers the solidus temperature of the Ni-based self-fluxing alloy. Furthermore, Si can reduce oxides in the coating 6. On the other hand, excessive Si causes embrittlement of the coating 6 and inhibits the machinability of the coating 6. From the viewpoint of the toughness and machinability of the coating 6, the content is preferably 5.00 mass% or less, more preferably 4.0 mass% or less, and particularly preferably 3.00 mass% or less.

In this Ni-based self-fluxing alloy, P plays a role in lowering the solidus temperature. Therefore, Si is not an essential element. From the viewpoint of the toughness and workability of the coating 6, it is preferable that this alloy does not substantially contain Si. In other words, an alloy in which the Si content is below the detection limit and an alloy in which Si is detected as an unavoidable impurity are preferable.

[Carbon (C)]
C contributes to the high hardness of the coating 6. C is added to the Ni-based self-fluxing alloy when high hardness is required for the coating 6. Therefore, C is not an essential element. From the viewpoint of high hardness, the C content is preferably 0.10 mass% or more, more preferably 0.20 mass% or more, and particularly preferably 0.40 mass% or more. Excess C causes embrittlement of the coating 6 and inhibits the machinability of the coating 6. From the viewpoint of toughness and machinability of the coating 6, this content is preferably 3.00 mass% or less, more preferably 2.50 mass% or less, and particularly preferably 2.00 mass% or less.

[Chromium (Cr)]
Cr contributes to the corrosion resistance of the coating 6. Cr is added to the Ni-based self-fluxing alloy when the coating 6 requires corrosion resistance. Therefore, Cr is not an essential element. From the viewpoint of corrosion resistance, the Cr content is preferably 2.0 mass% or more, more preferably 8.0 mass% or more, and particularly preferably 10.0 mass% or more. Excess Cr increases the liquidus temperature of the coating 6, which makes the remelting treatment of the coating 6 difficult. From the viewpoint of ease of remelting treatment, the content is preferably 30.0 mass% or less, more preferably 20.0 mass% or less, and particularly preferably 18.0 mass% or less.

[Molybdenum (Mo)]
Mo contributes to the corrosion resistance of the coating 6. Mo is added to the Ni-based self-fluxing alloy when the coating 6 requires corrosion resistance. Therefore, Mo is not an essential element. From the viewpoint of corrosion resistance, the content of Mo is preferably 0.5 mass% or more, more preferably 0.8 mass% or more, and particularly preferably 1.0 mass% or more. Excess Mo increases the liquidus temperature of the coating 6, causing difficulty in the remelting treatment of the coating 6. Excess Mo also causes the precipitation of coarse molybdenum-containing phosphides. The coarse phosphides cause the coating 6 to become embrittled and inhibit the machinability of the coating 6. From the viewpoint of ease of remelting treatment, toughness, and workability, the content is preferably 9.0 mass% or less, more preferably 5.0 mass% or less, and particularly preferably 4.0 mass% or less.

[Tungsten (W)]
W contributes to the corrosion resistance of the coating 6. W is added to the Ni-based self-fluxing alloy when the coating 6 requires corrosion resistance. Therefore, W is not an essential element. From the viewpoint of corrosion resistance, the content of W is preferably 1.0 mass% or more, more preferably 1.5 mass% or more, and particularly preferably 2.0 mass% or more. Excess W increases the liquidus temperature of the coating 6, causing difficulty in the remelting treatment of the coating 6. Excess W also causes the precipitation of coarse tungsten-containing phosphides. The coarse phosphides cause the coating 6 to become embrittled and inhibit the machinability of the coating 6. From the viewpoint of ease of remelting treatment, toughness, and workability, the content is preferably 18.0 mass% or less, more preferably 10.0 mass% or less, and particularly preferably 8.0 mass% or less.

[Mo and W]
This Ni-based self-fluxing alloy satisfies the following formula (1).
Mo% + W% / 2 ≦ 9.0 (1)
In this formula, Mo% represents the mass content of Mo, and W% represents the mass content of W. In the Ni-based self-fluxing alloy, W plays the same role as Mo. However, the effect obtained by adding W is about half of the effect obtained by adding the same amount of Mo. Therefore, in this embodiment, 1/2 is adopted as a coefficient for the content of W, and the molybdenum equivalent (Mo% + W% / 2) is calculated. In the Ni-based self-fluxing alloy that satisfies the above formula, the molybdenum equivalent is 9.0 mass% or less. From this Ni-based self-fluxing alloy, a film 6 that is easy to remelt and has excellent toughness and workability can be obtained. From these points of view, the molybdenum equivalent is more preferably 5.0 mass% or less, and particularly preferably 4.0 mass% or less. As mentioned above, Mo and W are not essential elements. Therefore, the molybdenum equivalent may be zero. In respect of corrosion resistance, the molybdenum equivalent is preferably 0.5 mass % or more, more preferably 0.8 mass % or more, and particularly preferably 1.0 mass % or more.

[Copper (Cu)]
Cu contributes to the corrosion resistance of the coating 6. Cu is added to the Ni-based self-fluxing alloy when corrosion resistance is required for the coating 6. Therefore, Cu is not an essential element. From the viewpoint of corrosion resistance, the Cu content is preferably 0.1 mass% or more, more preferably 0.5 mass% or more, and particularly preferably 1.0 mass% or more. Excess Cu actually inhibits the corrosion resistance of the coating 6. From the viewpoint of corrosion resistance, this content is preferably 10.0 mass% or less, more preferably 5.0 mass% or less, and particularly preferably 4.0 mass% or less.

[Manganese (Mn)]
Mn does not have a significant effect on the characteristics of the Ni-based self-fluxing alloy according to this embodiment. Mn is not an essential component of the Ni-based self-fluxing alloy. Therefore, the content of Mn in this Ni-based self-fluxing alloy may be zero. Excess Mn leads to a decrease in the content of essential elements. Therefore, the content of Mn is preferably 10.0 mass% or less.

[Iron (Fe)]
Fe does not have a significant effect on the characteristics of the Ni-based self-fluxing alloy according to this embodiment. Fe is not an essential component of the Ni-based self-fluxing alloy. Therefore, the content of Fe in this Ni-based self-fluxing alloy may be zero. Excess Fe leads to a decrease in the content of essential elements. Therefore, the content of Fe is preferably 10.0 mass% or less.

[Cobalt (Co)]
Co does not have a significant effect on the characteristics of the Ni-based self-fluxing alloy according to this embodiment. Co is not an essential component of the Ni-based self-fluxing alloy. Therefore, the content of Co in this Ni-based self-fluxing alloy may be zero. Excess Co leads to a decrease in the content of essential elements. Therefore, the content of Co is preferably 10.0 mass% or less.

[Aluminum (Al)]
In this embodiment, Al is an impurity. Excessive Al forms a strong oxide film and inhibits the denseness of the film 6. From the viewpoint of denseness, the Al content is preferably 0.20 mass% or less, more preferably 0.15 mass% or less, and particularly preferably 0.10 mass% or less. The ideal Al content is zero.

[Titanium (Ti)]
In this embodiment, Ti is an impurity. Excessive Ti forms a strong oxide film and inhibits the denseness of the film 6. From the viewpoint of denseness, the Ti content is preferably 0.20 mass% or less, more preferably 0.15 mass% or less, and particularly preferably 0.10 mass% or less. The ideal Ti content is zero.

[Zirconium (Zr)]
In this embodiment, Zr is an impurity. Excessive Zr forms a strong oxide film and inhibits the denseness of the film 6. From the viewpoint of denseness, the Zr content is preferably 0.20 mass% or less, more preferably 0.15 mass% or less, and particularly preferably 0.10 mass% or less. The ideal Zr content is zero.

[Hafnium (Hf)]
In this embodiment, Hf is an impurity. Excess Hf forms a strong oxide film and inhibits the denseness of the film 6. From the viewpoint of denseness, the Hf content is preferably 0.20 mass% or less, more preferably 0.15 mass% or less, and particularly preferably 0.10 mass% or less. The ideal Hf content is zero.

[Al, Ti, Zr and Hf]
This Ni-based self-fluxing alloy satisfies the following formula (2).
Al% + Ti% + Zr% + Hf% ≦ 0.20 (2)
In this formula, Al% represents the mass content of Al, Ti% represents the mass content of Ti, Zr% represents the mass content of Zr, and Hf% represents the mass content of Hf. In a Ni-based self-fluxing alloy that satisfies this formula, the total content of Al, Ti, Zr, and Hf is 0.20 mass% or less. In this Ni-based self-fluxing alloy, the formation of a strong oxide film is suppressed. Therefore, in this Ni-based self-fluxing alloy, a dense film 6 can be formed. From this viewpoint, this total content is preferably 0.20 mass% or less, more preferably 0.15 mass% or less, and particularly preferably 0.10 mass% or less. The ideal total content is zero.

[Ratio R1]
In this embodiment, the ratio R1 is calculated by the following formula (3).
R1 = (B% + Si%) / P% (3)
In this formula, B% represents the mass content of B, Si% represents the mass content of Si, and P% represents the mass content of P. As described above, each of P, B, and Si can lower the solidus temperature. The ratio R1 is the ratio of the contribution of B and Si to the contribution of P to the solidus temperature reduction. The ratio R1 is preferably 7.00 or less. In a powder having a ratio R1 of 7.00 or less, the contribution of P to the solidus temperature reduction is sufficiently large. From this powder, a dense coating 6 having excellent corrosion resistance, crack resistance, and toughness can be obtained. From this viewpoint, the ratio R1 is more preferably 4.50 or less, and particularly preferably 3.50 or less. The ratio R1 may be zero.

[Production of powder]
The powder is preferably obtained by atomization. Gas atomization, disk atomization, water atomization, centrifugal atomization, etc. are adopted. Preferred atomization methods are gas atomization and disk atomization. The powder obtained by atomization may be subjected to mechanical milling, etc.

[Formation of film]
Typically, the coating 6 is formed by a thermal spraying method. In the thermal spraying method, particles made of a Ni-based self-fluxing alloy are heated and melted, and then sprayed onto the main part 4. The molten metal that collides with the main part 4 solidifies to form a solidified layer. Since the particles are continuously sprayed, the molten particles also collide with the solidified layer and solidify, and the solidified layer grows. In this way, the coating 6 is formed. Since the Ni-based self-fluxing alloy according to this embodiment contains P, the particles can be melted by heating at a relatively low temperature. The temperature of this molten metal can be low. Therefore, damage to the main part 4 caused by heat can be suppressed. Even if the material of the main part 4 is a low melting point material (e.g., a Cu alloy), melting and deformation of the main part 4 can be suppressed. As described above, a part of the P-containing oxide is vaporized during the flight of the molten metal. Therefore, the amount of oxide contained in the coating 6 is small. This coating 6 is dense. The coating 6 may be formed by a method other than the thermal spraying method. As methods other than the thermal spraying method, overlay welding and centrifugal casting are exemplified. Since the solidus temperature of the Ni-based self-fluxing alloy is low, damage to the main portion 4 can be suppressed in any of the methods.

[Remelting process]
The coating 6 may be subjected to a remelting process. In the remelting process, the coating 6 is heated until it reaches a temperature equal to or higher than the solidus temperature. This heating generates a liquid phase in the coating 6. The coating 6 is in a solid-liquid mixed state. This liquid phase solidifies and the coating 6 is reformed. The remelting process increases the density of the coating 6. Since the Ni-based self-fluxing alloy according to this embodiment contains P, a liquid phase can be generated at a relatively low heating temperature. Therefore, damage to the main portion 4 caused by heat can be suppressed.

The effects of the Ni-based self-fluxing alloy according to the embodiment will be explained below, but the scope of the disclosure in this specification should not be interpreted as being limited based on the description of the embodiment.

[Example 1]
The metals having the compositions shown in Table 1 were melted to obtain a molten metal. The molten metal was poured into an alumina crucible. The molten metal was discharged from the nozzle of the crucible, and high-pressure nitrogen gas was sprayed onto it to obtain a powder. The powder was classified using a sieve to adjust the particle size to 45 μm or more and 125 μm or less. On the other hand, a plate-shaped main part made of SUS304 and having a size of "100 x 100 x 10 mm" was prepared. The surface of the main part was polished and finished to a flat surface. The powder was subjected to a gas flame spraying method to form a coating having a thickness of 1 mm on the surface of the main part. The main part and the coating were put into an electric furnace and held at a temperature of 940 ° C for 30 minutes. The coating was air-cooled to obtain the metal product of Example 1.

[Examples 2, 4, 7, and 9-23 and Comparative Examples 3-4, 6-8, and 10]
Metal products of Examples 2, 4, 7 and 9-23 and Comparative Examples 3-4, 6-8 and 10 were obtained in the same manner as in Example 1, except that the compositions were as shown in Tables 1 and 2 below.

[Examples 3 and 6 and Comparative Examples 2 and 9]
Metal products of Examples 3 and 6 and Comparative Examples 2 and 9 were obtained in the same manner as in Example 1, except that the compositions were as shown in Tables 1 and 2 below, and the main parts were made of SUS316L.

[Examples 5 and 8 and Comparative Examples 1 and 5]
Metal products of Examples 5 and 8 and Comparative Examples 1 and 5 were obtained in the same manner as in Example 1, except that the compositions were as shown in Tables 1 and 2 below, and the main part was made of SS400.

[Residual Pores and Residual Oxides]
A test piece was cut out from the coating before the remelting treatment, and the cross section was polished. The test piece was photographed near the center of the coating in the thickness direction at 100 times magnification using an optical microscope. The obtained image was observed, and the number of residual pores and residual oxides with a size (major axis) of 20 μm or more in an area of 500 × 500 μm was counted. The results were ranked according to the following criteria.
A: 5 or less B: 6 or more but less than 30 C: 30 or more Test pieces were similarly taken from the coating after the remelting treatment and were ranked in the same manner. The results are shown in Tables 3 and 4 below.

[Corrosion resistance]
Test pieces were cut out from the coating after the remelting treatment, and the cross sections were polished. The test pieces were subjected to a corrosion resistance test. The test pieces of Examples 1-4, 6-7, and 9-23 and Comparative Examples 2-4 and 6-10 were subjected to a salt spray test. The test pieces of Examples 5 and 8 and Comparative Examples 1 and 5 were subjected to a high temperature and high humidity test. The test conditions for each were as follows:
Salt spray test Salt water composition: 5% NaCl aqueous solution Temperature: 35°C
Time: 96 hours High temperature and humidity test Temperature: 70°C
Humidity: 95% RH
Time: After 96 hours of testing, the coating and the interface between the coating and the main part were observed and rated according to the following criteria.
A: Rust is observed in some areas. B: Rust is observed over the entire surface. The results are shown in Tables 3 and 4 below.

[Transform]
A base was prepared, and the metal product after the remelting treatment was placed on the base so that the coating was in contact with the base. The rattle of the metal product was observed and rated according to the following criteria.
A: No rattling (no deformation of the main part)
B: There is rattling (the main part is deformed)
The results are shown in Tables 3 and 4 below.

各合金は、表１及び２に示された元素以外に、不可避的不純物を含有しうる。

In addition to the elements shown in Tables 1 and 2, each alloy may contain unavoidable impurities.

As shown in Tables 3 and 4, the metal products of each example have excellent performance. These evaluation results clearly demonstrate the superiority of this Ni-based self-fluxing alloy.

The alloys described above are suitable for a variety of applications where self-fluxing is required.

2: Metal product 4: Main part 6: Coating

Claims (6)

P: 0.10% by mass or more and 10.00% by mass or less,
B: 0.00% by mass or more and 5.00% by mass or less,
Si: 0.00% or more and 5.00% or less by mass,
C: 0.0% by mass or more and 3.0% by mass or less,
Cr: 0.0% by mass or more and 30.0% by mass or less,
Mo: 0.0% by mass or more and 9.0% by mass or less,
W: 0.0% by mass or more and 18.0% by mass or less,
Cu: 0.0% by mass or more and 10.0% by mass or less,
Mn: 0.0% by mass or more and 10.0% by mass or less,
Fe: 0.0% by mass or more and 10.0% by mass or less,
Co: 0.0% by mass or more and 10.0% by mass or less,
Al: 0.00% by mass or more and 0.20% by mass or less,
Ti: 0.00% by mass or more and 0.20% by mass or less,
Zr: 0.00% by mass or more and 0.20% by mass or less,
and Hf: 0.00% by mass or more and 0.20% by mass or less, with the remainder being Ni and unavoidable impurities, and satisfying the following mathematical expressions (1) and (2),
A Ni-based self-fluxing alloy having a ratio R1 calculated by the following formula (3) of 7.00 or less.
Mo% + W% / 2 ≦ 9.0 (1)
Al% + Ti% + Zr% + Hf% ≦ 0.20 (2)
R1 = (B% + Si%) / P% (3)
(In these formulas, Mo% represents the mass content of Mo, W% represents the mass content of W, Al% represents the mass content of Al, Ti% represents the mass content of Ti, Zr% represents the mass content of Zr, Hf% represents the mass content of Hf, B% represents the mass content of B, Si% represents the mass content of Si, and P% represents the mass content of P.) The alloy of claim 1, which is substantially free of B. The alloy according to claim 1 or 2, which is substantially free of Si. The material is a Ni-based self-fluxing alloy,
The Ni-based self-fluxing alloy is
P: 0.10% by mass or more and 10.00% by mass or less,
B: 0.00% by mass or more and 5.00% by mass or less,
Si: 0.00% or more and 5.00% or less by mass,
C: 0.0% by mass or more and 3.0% by mass or less,
Cr: 0.0% by mass or more and 30.0% by mass or less,
Mo: 0.0% by mass or more and 9.0% by mass or less,
W: 0.0% by mass or more and 18.0% by mass or less,
Cu: 0.0% by mass or more and 10.0% by mass or less,
Mn: 0.0% by mass or more and 10.0% by mass or less,
Fe: 0.0% by mass or more and 10.0% by mass or less,
Co: 0.0% by mass or more and 10.0% by mass or less,
Al: 0.00% by mass or more and 0.20% by mass or less,
Ti: 0.00% by mass or more and 0.20% by mass or less,
Zr: 0.00% by mass or more and 0.20% by mass or less,
and Hf: 0.00% by mass or more and 0.20% by mass or less, with the remainder being Ni and unavoidable impurities, and satisfying the following mathematical expressions (1) and (2),
A powder having a ratio R1 calculated by the following formula (3) of 7.00 or less.
Mo% + W% / 2 ≦ 9.0 (1)
Al% + Ti% + Zr% + Hf% ≦ 0.20 (2)
R1 = (B% + Si%) / P% (3)
(In these formulas, Mo% represents the mass content of Mo, W% represents the mass content of W, Al% represents the mass content of Al, Ti% represents the mass content of Ti, Zr% represents the mass content of Zr, Hf% represents the mass content of Hf, B% represents the mass content of B, Si% represents the mass content of Si, and P% represents the mass content of P.) The material is a Ni-based self-fluxing alloy,
The Ni-based self-fluxing alloy is
P: 0.10% by mass or more and 10.00% by mass or less,
B: 0.00% by mass or more and 5.00% by mass or less,
Si: 0.00% or more and 5.00% or less by mass,
C: 0.0% by mass or more and 3.0% by mass or less,
Cr: 0.0% by mass or more and 30.0% by mass or less,
Mo: 0.0% by mass or more and 9.0% by mass or less,
W: 0.0% by mass or more and 18.0% by mass or less,
Cu: 0.0% by mass or more and 10.0% by mass or less,
Mn: 0.0% by mass or more and 10.0% by mass or less,
Fe: 0.0% by mass or more and 10.0% by mass or less,
Co: 0.0% by mass or more and 10.0% by mass or less,
Al: 0.00% by mass or more and 0.20% by mass or less,
Ti: 0.00% by mass or more and 0.20% by mass or less,
Zr: 0.00% by mass or more and 0.20% by mass or less,
and Hf: 0.00% by mass or more and 0.20% by mass or less, with the remainder being Ni and unavoidable impurities, and satisfying the following mathematical expressions (1) and (2),
A coating having a ratio R1 calculated by the following formula (3) of 7.00 or less.
Mo% + W% / 2 ≦ 9.0 (1)
Al% + Ti% + Zr% + Hf% ≦ 0.20 (2)
R1 = (B% + Si%) / P% (3)
(In these formulas, Mo% represents the mass content of Mo, W% represents the mass content of W, Al% represents the mass content of Al, Ti% represents the mass content of Ti, Zr% represents the mass content of Zr, Hf% represents the mass content of Hf, B% represents the mass content of B, Si% represents the mass content of Si, and P% represents the mass content of P.) The nozzle has a main portion and a coating covering a surface of the main portion,
The material of the coating is a Ni-based self-fluxing alloy,
The Ni-based self-fluxing alloy is
P: 0.10% by mass or more and 10.00% by mass or less,
B: 0.00% by mass or more and 5.00% by mass or less,
Si: 0.00% or more and 5.00% or less by mass,
C: 0.0% by mass or more and 3.0% by mass or less,
Cr: 0.0% by mass or more and 30.0% by mass or less,
Mo: 0.0% by mass or more and 9.0% by mass or less,
W: 0.0% by mass or more and 18.0% by mass or less,
Cu: 0.0% by mass or more and 10.0% by mass or less,
Mn: 0.0% by mass or more and 10.0% by mass or less,
Fe: 0.0% by mass or more and 10.0% by mass or less,
Co: 0.0% by mass or more and 10.0% by mass or less,
Al: 0.00% by mass or more and 0.20% by mass or less,
Ti: 0.00% by mass or more and 0.20% by mass or less,
Zr: 0.00% by mass or more and 0.20% by mass or less,
and Hf: 0.00% by mass or more and 0.20% by mass or less, with the remainder being Ni and unavoidable impurities, and satisfying the following mathematical expressions (1) and (2),
A metal product having a ratio R1 calculated by the following formula (3) of 7.00 or less.
Mo% + W% / 2 ≦ 9.0 (1)
Al% + Ti% + Zr% + Hf% ≦ 0.20 (2)
R1 = (B% + Si%) / P% (3)
(In these formulas, Mo% represents the mass content of Mo, W% represents the mass content of W, Al% represents the mass content of Al, Ti% represents the mass content of Ti, Zr% represents the mass content of Zr, Hf% represents the mass content of Hf, B% represents the mass content of B, Si% represents the mass content of Si, and P% represents the mass content of P.)

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