JP7702802B2 - Vanadium silicocarbide film-coated member and method for producing same - Google Patents

Description

The present invention relates to a vanadium silicocarbide film-coated member and a method for producing the same.

Conventionally, it is known that a hard film having a harder hardness than the substrate is formed on the substrate surface of dies used in press working and forging, cutting tools, forging tools, automobile parts, etc., in order to prevent wear of the die surface and damage to the workpiece caused by contact friction during processing of the workpiece. Patent Document 1 describes a vanadium silicocarbide film-coated member in which a vanadium silicocarbide film (VSiC film) containing vanadium, carbon, and silicon, which is a type of hard film with excellent adhesion to the substrate and wear resistance, is formed on the substrate surface by an ion plating method.

Japanese Patent Application Publication No. 7-300649

Depending on the application, vanadium silicocarbide film-coated components are used with a large surface pressure on the component surface. For example, when a vanadium silicocarbide film-coated component is used as a forging die, a large surface pressure is applied to the component surface each time molding is performed. When a vanadium silicocarbide film-coated component is used in such a condition, if the adhesion between the substrate and the vanadium silicocarbide film is insufficient, the vanadium silicocarbide film will peel off, significantly shortening the product life. For this reason, there has been a demand for further improvement in the adhesion between the substrate and vanadium silicocarbide formed on the surfaces of dies used in press working and forging, cutting tools, gear cutting tools, forging tools, automotive parts, etc.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vanadium silicocarbide film-coated member capable of improving the adhesion between the vanadium silicocarbide film and a substrate, and a method for producing the same.

The inventors discovered that by forming a nitride layer with a predetermined surface roughness on the surface of the substrate on which the vanadium silicocarbide film is to be formed, and then forming the vanadium silicocarbide film on the nitride layer, it is possible to obtain a vanadium silicocarbide film-coated member that has high adhesion to the substrate, and thus completed the present invention.

Aspects of the present invention that solve the above problems are listed below.
[1] A substrate,
A nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less formed on the surface of the base material;
a vanadium silicocarbide film formed on the nitride layer;
the vanadium silicocarbide film contains vanadium, silicon, and carbon, and the sum of the vanadium element concentration, the silicon element concentration, and the carbon element concentration in the film is 90 at % or more;
The vanadium silicocarbide film-coated member has a vanadium element concentration of 3 to 15 at %, a silicon element concentration of 15 to 30 at %, and a carbon element concentration of 60 to 80 at % .
[2] A substrate,
A nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less formed on the surface of the base material;
a vanadium silicocarbide film formed on the nitride layer;
the vanadium silicocarbide film contains vanadium, silicon, and carbon, and the sum of the vanadium element concentration, the silicon element concentration, and the carbon element concentration in the film is 90 at % or more;
A vanadium silicocarbide film-coated member that satisfies the following formula (1):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≧25 at% (1)
[3] A substrate,
A nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less formed on the surface of the base material;
a vanadium silicocarbide film formed on the nitride layer;
the vanadium silicocarbide film contains vanadium, silicon, and carbon, and the sum of the vanadium element concentration, the silicon element concentration, and the carbon element concentration in the film is 90 at % or more;
A vanadium silicocarbide film-coated member that satisfies the following formula (2):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≧30 at% (2)
[4] A substrate,
A nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less formed on the surface of the base material;
a vanadium silicocarbide film formed on the nitride layer;
the vanadium silicocarbide film contains vanadium, silicon, and carbon, and the sum of the vanadium element concentration, the silicon element concentration, and the carbon element concentration in the film is 90 at % or more;
A vanadium silicocarbide film-coated member that satisfies the following formula (3):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≦36 at % (3)
[5] A substrate,
A nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less formed on the surface of the base material;
a vanadium silicocarbide film formed on the nitride layer;
the vanadium silicocarbide film contains vanadium, silicon, and carbon, and the sum of the vanadium element concentration, the silicon element concentration, and the carbon element concentration in the film is 90 at % or more;
A vanadium silicocarbide film-coated member satisfying the following formula (4):
The silicon element concentration/(the vanadium element concentration+the silicon element concentration)>0.7 (4)
[ 6 ] The vanadium silicocarbide film-coated member according to any one of [1] to [5] , wherein the surface roughness Rzjis of the nitride layer is 0.25 μm or more.
[ 7 ] The vanadium silicocarbide film-coated member according to any one of [1] to [5] , wherein the surface roughness Rzjis of the nitride layer is 0.4 μm or more.
[ 8 ] The vanadium silicocarbide film-coated member according to any one of [1] to [7] , wherein the substrate is a steel material.
[ 9 ] A nitriding process for forming a nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less on the surface of the base material;
a vanadium silicocarbide film forming step of forming a vanadium silicocarbide film on the nitride layer formed in the nitriding treatment step, the vanadium silicocarbide film containing vanadium, silicon and carbon, and having a total vanadium element concentration, silicon element concentration and carbon element concentration of 90 at % or more in the film ,
%。 Vanadium silicocarbide film-coated member of the present invention, wherein the vanadium element concentration is 3 to 15 at %, the silicon element concentration is 15 to 30 at %, and the carbon element concentration is 60 to 80 at % .
[10] A nitriding process for forming a nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less on a surface of a substrate;
a vanadium silicocarbide film forming step of forming a vanadium silicocarbide film on the nitride layer formed in the nitriding treatment step, the vanadium silicocarbide film containing vanadium, silicon and carbon, and having a total vanadium element concentration, silicon element concentration and carbon element concentration of 90 at % or more in the film,
A method for producing a vanadium silicocarbide film-coated member, which satisfies the following formula (1):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≧25 at% (1)
[11] A nitriding process for forming a nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less on a surface of a substrate;
a vanadium silicocarbide film forming step of forming a vanadium silicocarbide film on the nitride layer formed in the nitriding treatment step, the vanadium silicocarbide film containing vanadium, silicon and carbon, and having a total vanadium element concentration, silicon element concentration and carbon element concentration of 90 at % or more in the film,
A method for producing a vanadium silicocarbide film-coated member, which satisfies the following formula (2):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≧30 at% (2)
[12] A nitriding process for forming a nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less on a surface of a substrate;
a vanadium silicocarbide film forming step of forming a vanadium silicocarbide film on the nitride layer formed in the nitriding treatment step, the vanadium silicocarbide film containing vanadium, silicon and carbon, and having a total vanadium element concentration, silicon element concentration and carbon element concentration of 90 at % or more in the film,
A method for producing a vanadium silicocarbide film-coated member, which satisfies the following formula (3):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≦36 at % (3)
[13] A nitriding process for forming a nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less on a surface of a substrate;
a vanadium silicocarbide film forming step of forming a vanadium silicocarbide film on the nitride layer formed in the nitriding treatment step, the vanadium silicocarbide film containing vanadium, silicon and carbon, and having a total vanadium element concentration, silicon element concentration and carbon element concentration of 90 at % or more in the film,
A method for producing a vanadium silicocarbide film-coated member, which satisfies the following formula (4):
The silicon element concentration/(the vanadium element concentration+the silicon element concentration)>0.7 (4)
[ 14 ] The method for producing a vanadium silicocarbide film-coated member according to any one of [9] to [13] , wherein the nitride layer has a surface roughness Rzjis of 0.25 μm or more.
[ 15 ] The method for producing a vanadium silicocarbide film-coated member according to any one of [9] to [13] , wherein the surface roughness Rzjis of the nitride layer is 0.4 μm or more.
[ 16 ] The method for producing a vanadium silicon carbide film-coated member according to any one of [9] to [15] , wherein in the nitriding treatment step, hydrogen gas and nitrogen gas are converted into plasma to perform nitriding treatment on the substrate.
[ 17 ] The method for producing a vanadium silicocarbide film-coated member according to any one of [9] to [16] , wherein the substrate is a steel material.
[ 18 ] The method for producing a vanadium silicocarbide film-coated member according to any one of [9] to [17] , wherein in the vanadium silicocarbide film-forming step, vanadium chloride gas, a silicon source gas, a hydrocarbon gas and a hydrogen gas are supplied, and the vanadium silicocarbide film is formed by a plasma chemical vapor deposition method.
[19] The method for producing a vanadium silicocarbide film-coated member according to [18], wherein in the vanadium silicocarbide film formation step, argon gas is further supplied, and a flow rate ratio of the vanadium chloride gas, the silicon source gas, the hydrocarbon gas, the hydrogen gas and the argon gas is 1:0.25-2:3-20:20-35:0.5-2.

According to the present invention, it is possible to provide a vanadium silicocarbide film-coated member capable of improving the adhesion between the vanadium silicocarbide film and a substrate, and a method for producing the same.

1 is a diagram showing a schematic configuration of a vanadium silicocarbide film-coated member according to an embodiment of the present invention. 1 is a diagram showing a schematic configuration of a vanadium silicocarbide film forming apparatus according to an embodiment of the present invention; FIG. 2 is a diagram showing the shape of a test piece. FIG. 1 is a schematic diagram of a ball-on-disk test.

One embodiment of the present invention will be described below with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals to avoid redundant description.

Figure 1 shows the schematic configuration of a vanadium silicocarbide film-coated member according to this embodiment.

The vanadium silicocarbide film-coated member 1 is composed of a vanadium silicocarbide film-forming substrate 2 and a vanadium silicocarbide film 3 formed on the surface of the vanadium silicocarbide film-forming substrate 2.

The vanadium silicocarbide film forming substrate 2 is composed of a substrate 2b and a nitride layer 2a formed on the surface of the substrate 2b.

The material of the substrate 2b is not particularly limited, and a material suitable for the application of the vanadium silicocarbide film coated member 1 is used. For example, various steel materials are used as the material of the substrate 2b. In this specification, steel materials are materials mainly composed of iron, 2% or less of carbon, and other components. Steel materials used for dies and tools include die steel, high-speed tool steel, matrix high-speed steel, etc., which are explained below.

Die steel is a type of alloy tool steel for cold working dies. It is widely used because it can be quenched to a high degree of hardness, has little quench distortion, and is highly wear-resistant. Die steel contains vanadium, molybdenum, tungsten, chromium, etc. "SKD" is used as the symbol for steel-based materials in the JIS (Japanese Industrial Standards), and typical steel types include SKD-11 and SKD-61.

High-speed tool steel, also known as HSS, is a material that has superior wear resistance, impact resistance, and toughness compared to die steel. The JIS symbol for steel-based materials is "SKH," which is summarized in JIS G4403. Representative steel types include SKH-51 and SKH-55.

Matrix HSS is a material designed to obtain high hardness, high toughness, and high heat resistance by lowering the carbon content compared to high speed tool steels, reducing eutectic carbides, and increasing the ratio of alloy elements in the matrix. Products commonly supplied on the market include YXR3, YXR7, and YXR33 from Hitachi Metals Tool Steel Co., Ltd. These materials are used in dies, which require high dimensional accuracy among tool steels, punches used in shearing, blades, and the like. For this reason, the surface coating shown in this embodiment plays an important role in enhancing the characteristics of high hardness, high toughness, and high heat resistance described above.

The nitride layer 2a of the vanadium silicocarbide film-forming substrate 2 is a layer consisting of at least one of a compound layer and a diffusion layer, and is formed by subjecting the substrate 2b to a nitriding treatment. In terms of iron nitrides, the nitride layer is composed of γ' phase (Fe ₄ N), ε phase (Fe _2-3 N), and metastable α" phase (Fe ₁₆ N), etc. In the examples of the present application, nitrides containing alloy elements are composed similarly to these. For example, when die steel, high speed tool steel, or matrix high speed steel is used as the steel material, nitrides of vanadium, molybdenum, tungsten, chromium, etc. are precipitated. The presence of the nitride layer 2 a on the surface of the substrate 2 b improves the chemical compatibility between the vanadium silicocarbide film-forming substrate 2 and the vanadium silicocarbide film 3, and also eliminates lattice mismatch. This makes it possible to further improve the adhesion between the vanadium silicocarbide film-forming substrate 2 and the vanadium silicocarbide film 3. From the viewpoint of further improving the adhesion between the vanadium silicocarbide film-forming substrate 2 and the vanadium silicocarbide film 3, it is preferable that no compound layer is formed on the nitride layer 2 a.

The formation of the nitride layer 2a on the surface of the substrate 2b is confirmed by corroding the cut surface of the substrate 2 for forming the vanadium silicocarbide film and observing the colored state of the corroded cut surface using a metallurgical microscope, in accordance with the provisions of "JIS G 0562 Method for measuring the depth of nitride layers in steel." In the microscope image, the compound layer of the nitride layer 2a is colored white, and the diffusion layer of the nitride layer 2a is colored black, making it possible to visually distinguish whether or not there is a compound layer in the nitride layer 2a, and the boundary between the nitride layer 2a and the substrate 2b.

The nitriding depth of the nitrided layer 2a is not particularly limited, but is preferably 20 to 250 μm. When the nitriding depth of the nitrided layer 2a is 20 μm or more, it is possible to suppress the sudden change in characteristics in the depth direction, such as the change in hardness due to nitriding. On the other hand, when the nitriding depth is 250 μm or less, the nitriding treatment time can be shortened, excessive nitriding can be suppressed, and the surface roughness of the nitrided layer can be easily controlled. The "nitriding depth" of the nitrided layer 2a is the distance from the surface of the nitrided layer 2a to the position where the hardness is the substrate hardness x 1.15 HV. The "substrate hardness" is measured by the following method. First, the cut surface of the test piece on which the nitrided layer is formed is polished and mirror-finished in accordance with the provisions of "JIS G 0562 Method for measuring the depth of nitrided layer of steel". Next, a Vickers hardness test is performed with a load of 25 gf using a micro Vickers hardness tester, and a hardness transition curve from the surface of the test piece is created based on the results. Then, the point on the transition curve where the hardness value converges is identified, and the hardness value at this point is set as the substrate hardness.

The nitride layer 2a formed on the surface of the substrate 2b has a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less. As shown in the examples described later, the substrate 2 for forming the vanadium silicocarbide film has a nitride layer 2a on the surface of the substrate 2b with a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less, thereby improving the adhesion between the substrate 2 for forming the vanadium silicocarbide film and the vanadium silicocarbide film 3. From the viewpoint of further enhancing this effect, the surface roughness Rzjis of the nitride layer 2a is preferably 0.25 μm or more, and more preferably 0.4 μm or more.

(Vanadium silicocarbide film)
The vanadium silicocarbide film-coated member 1 has a vanadium silicocarbide film 3 on a nitride layer 2a having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less. The vanadium silicocarbide film 3 contains vanadium (V), silicon (Si), and carbon (C), and has a total vanadium element concentration, silicon element concentration, and carbon element concentration of 90 at% or more. The total vanadium element concentration, silicon element concentration, and carbon element concentration of the vanadium silicocarbide film 3 is more preferably 91 at% or more, and even more preferably 92 at% or more.

The vanadium, silicon, and carbon element concentrations in the vanadium silicocarbide film 3 can be measured by composition analysis using an electron probe microanalyzer (hereinafter referred to as EPMA). When the thickness of the vanadium silicocarbide film 3 is 1 μm or less, the EPMA measurement results include the influence of the component composition of the substrate. For this reason, when performing a composition analysis of a thin vanadium silicocarbide film 3, it is necessary to perform an EPMA measurement of only the substrate 2b in advance, and subtract the vanadium, silicon, and carbon element concentrations derived from the substrate from the EPMA measurement results after the vanadium silicocarbide film 3 is formed.

The vanadium silicocarbide film 3 preferably has a vanadium element concentration of 3 to 15 at%, a silicon element concentration of 15 to 30 at%, and a carbon element concentration of 60 to 80 at%. The vanadium element concentration is more preferably 4 to 15 at%.

It is preferable that the vanadium element concentration, silicon element concentration, and carbon element concentration in the vanadium silicocarbide film 3 satisfy the following formula (1), whereby the adhesion between the vanadium silicocarbide film-forming substrate 2 and the vanadium silicocarbide film 3 can be further improved.
(carbon element concentration−vanadium element concentration−silicon element concentration)≧25 at% (1)

Furthermore, when the following formula (2) is satisfied, the coefficient of friction between the vanadium silicocarbide film coated member 1 and a counter member that comes into contact with the vanadium silicocarbide film coated member 1 can be made small.
(carbon element concentration−vanadium element concentration−silicon element concentration)≧30 at% (2)

When the following formula (3) is satisfied, the hardness of the vanadium silicate film 3 can be increased.
(carbon element concentration−vanadium element concentration−silicon element concentration)≦36 at% (3)

When the following formula (4) is satisfied, the heat resistance of the vanadium silicate film 3 can be improved.
Silicon element concentration/(vanadium element concentration+silicon element concentration)>0.7 (4)

The thickness of the vanadium silicocarbide film 3 is set appropriately depending on the application of the vanadium silicocarbide film-coated member 1, but for example, when the vanadium silicocarbide film 3 is formed on the substrate of a mold, the film thickness is preferably 0.5 to 4 μm.

The vanadium silicocarbide film 3 may contain elements other than vanadium, silicon, and carbon, as long as the effect of improving adhesion is not impaired. Examples of elements other than vanadium, silicon, and carbon include fluorine, chlorine, hydrogen, and argon contained in the raw material gas and argon gas supplied in the vanadium silicocarbide film formation process, and oxygen and nitrogen contained in the gas remaining in the chamber of the vanadium silicocarbide film formation device described below. The vanadium, silicon, and elements other than carbon contained in the vanadium silicocarbide film 3 are preferably limited to 9 at% or less, and more preferably limited to 8 at% or less.

Next, a method for manufacturing the vanadium silicocarbide film-forming substrate 2 and the vanadium silicocarbide film-coated member 1 will be described. In this embodiment, the vanadium silicocarbide film-forming substrate 2 is produced by forming a nitride layer 2a having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less on the surface of the substrate 2b. Thereafter, the vanadium silicocarbide film 3 is formed on the nitride layer 2a to produce the vanadium silicocarbide film-coated member 1.

First, the substrate 2b is prepared. The substrate 2b is preferably polished until the surface roughness Rzjis is 0.1 μm or less. By making the surface roughness Rzjis of the substrate 2b 0.1 μm or less, the nitride layer 2a can be formed uniformly on the surface of the substrate 2b, which is believed to further improve adhesion.

<Nitriding process>
Next, the substrate 2b is subjected to a nitriding treatment to prepare the substrate 2 for forming the vanadium silicocarbide film. In the nitriding treatment step, a nitride layer 2a having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less is formed on the surface of the substrate 2b.

As a nitriding treatment apparatus for forming the nitride layer 2a and an apparatus for forming the vanadium silicocarbide film-coated member 1 described later, for example, a plasma treatment apparatus 10 as shown in FIG. 2 is used. The plasma treatment apparatus 10 includes a chamber 11 into which the substrate 2b is carried, an anode 12, a cathode 13, and a DC pulse power supply 14 for applying a pulse voltage between the anode 12 and the cathode 13. A gas supply pipe 15 for supplying each raw material gas is connected to the upper part of the chamber 11, and a gas exhaust pipe 16 for exhausting the gas in the chamber 11 is connected to the lower part of the chamber 11. A vacuum pump (not shown) is provided downstream of the gas exhaust pipe 16. The cathode 13 also serves as a support stand for supporting the substrate 2b, and the substrate 2b carried into the chamber 11 is placed on the cathode 13. A heater (not shown) is provided inside the chamber 11, and the temperature of the substrate 2b is adjusted by adjusting the atmospheric temperature in the chamber 11 with the heater.

The configuration of the plasma processing apparatus 10 is not limited to the configuration described in this embodiment. For example, a high-frequency power supply may be used instead of the DC pulse power supply 14, or a shower head (not shown) may be provided to supply the raw material gas and used as the anode 12. Also, the substrate 2b may be heated only by a glow current without providing a heater. In other words, the plasma processing apparatus 10 may be configured to be capable of turning the raw material gas supplied into the chamber 11 into plasma and to form a nitride layer 2a on the substrate 2b.

The nitriding method for the substrate 2b is not particularly limited, and for example, plasma nitriding or gas nitriding can be applied. However, when the vanadium silicocarbide film is formed by plasma chemical vapor deposition and the nitriding is performed by plasma nitriding, the nitriding of the substrate 2b and the formation of the vanadium silicocarbide film 3 can be performed in the same plasma processing device. Therefore, from the viewpoint of efficiently manufacturing the vanadium silicocarbide film-coated member 1 compared to using separate devices, it is preferable to perform the nitriding of the substrate 2b by plasma nitriding. In addition, by performing the nitriding and plasma nitriding in the same plasma processing device, the effects of surface oxidation can be prevented, which is preferable. In addition, since the film can be formed without cooling or cleaning the substrate 2b, it is possible to efficiently manufacture the vanadium silicocarbide film-coated member 1.

The plasma nitriding process is a process in which hydrogen gas and nitrogen gas supplied into a plasma processing device are turned into plasma to form a nitride layer 2a on the surface of the substrate 2b. During this plasma nitriding process, argon gas may be supplied as appropriate in addition to hydrogen gas and nitrogen gas. Argon gas contributes to stabilizing the plasma and improving the ion density by ionizing other molecules with argon ions. The surface roughness Rzjis of the nitride layer 2a can be controlled by appropriately changing the nitriding process time, the partial pressure ratio of the supplied hydrogen gas and nitrogen gas, the voltage, the current density, the duty ratio, etc.

From the viewpoint of productivity, the processing time for the plasma nitriding process is preferably 30 to 300 minutes. More preferably, it is 60 to 240 minutes.

The ratio of the nitrogen partial pressure to the hydrogen partial pressure in the plasma processing device, that is, the nitrogen partial pressure/hydrogen partial pressure, is preferably 0.15 to 2.0, which makes it easier to nitride the substrate 2b. From the viewpoint of suppressing the formation of a compound layer in the nitride layer 2a, the nitrogen partial pressure/hydrogen partial pressure is preferably 1.0 or less, and more preferably 0.70 or less. On the other hand, the lower limit of the nitrogen partial pressure/hydrogen partial pressure is preferably 0.25 or more. The pressure in the chamber 11 during the plasma nitriding process is preferably 30 to 200 Pa.

The power supply voltage during the plasma nitriding treatment is preferably 1000 to 2500 V, and more preferably 1200 to 2000 V. The current density during the plasma nitriding treatment is preferably 0.2 to 0.7 mA/ ^cm2 , and more preferably 0.3 to 0.6 mA/ ^cm2 . The duty ratio calculated by the following formula, which is defined by the voltage application time per cycle, is preferably 5 to 60%.
Duty ratio (%) = 100 x application time (ON time) / {application time (ON time)
time) + application stop time (OFF time)}

In this embodiment, the vanadium silicocarbide film forming substrate 2 is manufactured by the above nitriding process.

<Vanadium silicocarbide film formation process>
Next, the vanadium silicocarbide film 3 is formed on the nitride layer 2a of the vanadium silicocarbide film-forming substrate 2 by plasma chemical vapor deposition.

Vanadium chloride gas, silicon source gas, hydrocarbon gas, and hydrogen gas are supplied into the chamber 11 of the plasma processing device 10 as raw material gases for forming the vanadium silicocarbide film 3, and a pulse voltage is applied between the anode 12 and the cathode 13 using the pulse power supply 14. As a result, the raw material gases supplied into the chamber 11 are converted into plasma between the anode 12 and the cathode 13, and the vanadium silicocarbide film 3 is formed on the nitride layer 2a. In this way, the vanadium silicocarbide film-coated member 1 in this embodiment is manufactured.

As the vanadium chloride gas, for example, vanadium tetrachloride (VCl ₄ ) gas, vanadium oxide trichloride (VOCl ₃ ) gas, etc. are used. Note that vanadium tetrachloride gas is preferably used from the viewpoint that the number of elements constituting the gas is small and that it is easy to remove impurities from the vanadium silicocarbide film 3. In addition, vanadium tetrachloride gas is easily available, is a liquid at room temperature, and can be easily supplied as a gas, so it is preferable to use it from this viewpoint as well.

As the silicon source gas, for example, a silane-based gas such as monomethylsilane gas, dimethylsilane gas, trimethylsilane gas, tetramethylsilane gas, silicon tetrachloride gas, silicon tetrafluoride gas, etc. can be used.

Examples of the hydrocarbon gas that can be used include methane gas, ethane gas, ethylene gas, and acetylene gas. The gases exemplified here may be supplied alone or in combination of two or more types of gases.

When silicon tetrachloride gas is contained in the raw material gas supplied in the vanadium silicocarbide film formation process, the vanadium silicocarbide film 3 will inevitably contain chlorine as an impurity in the remainder excluding vanadium, silicon, and carbon. Since chlorine easily combines with hydrogen gas, when hydrogen gas is contained in the raw material gas, the chlorine generated from the vanadium chloride gas combines with hydrogen and is easily discharged outside the system. This makes it possible to suppress the intrusion of chlorine into the vanadium silicocarbide film 3.

The remainder of the vanadium silicocarbide film 3 may contain unavoidable impurities other than chlorine. When vanadium chloride gas and silicon tetrachloride gas are supplied into the chamber 11 in the vanadium silicocarbide film formation process, the volumetric flow rate of the hydrogen gas supplied into the chamber 11 is preferably 5 to 25 times the total volumetric flow rate of the vanadium chloride gas and the silicon tetrachloride gas. Argon gas may be supplied into the chamber 11 as necessary, since argon ions ionize other molecules, thereby contributing to stabilizing the plasma and improving ion density.

In the vanadium silicocarbide film formation process, the flow rate ratio of vanadium chloride gas, silicon source gas, hydrocarbon gas, hydrogen gas, and argon gas is preferably 1:0.25-2:3-20:20-35:0.5-2. This makes it easier to obtain a vanadium silicocarbide film 3 in which the total of the vanadium element concentration, silicon element concentration, and carbon element concentration in the film is 90 at% or more. In this specification, the "vanadium chloride gas flow rate," "silicon source gas flow rate," "hydrocarbon gas flow rate," "hydrogen gas flow rate," and "argon gas flow rate" used in calculating the above flow rate ratios are volumetric flow rates at 0°C and 1 atm.

The pressure in the chamber 11 during the vanadium silicocarbide film formation process is preferably, for example, 30 to 200 Pa. The power applied from the DC pulse power supply 14 during the vanadium silicocarbide film formation process is preferably 100 to 1000 W. The voltage applied from the DC pulse power supply 14 is preferably 1000 to 2000 V. The duty ratio is preferably 10% to 60%. The vanadium element concentration, silicon element concentration, and carbon element concentration in the vanadium silicocarbide film 3 can be controlled by appropriately setting the flow rate of each raw material gas, the power of the pulse power supply, the voltage of the pulse power supply, and the duty ratio.

By the vanadium silicocarbide film formation process as described above, a vanadium silicocarbide film 3 having a total vanadium element concentration, silicon element concentration, and carbon element concentration of 90 at% or more is formed on the nitride layer 2a having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less. The vanadium silicocarbide film-coated member 1 produced in this manner has excellent adhesion between the vanadium silicocarbide film-forming substrate 2 and the vanadium silicocarbide film 3.

Although one embodiment of the present invention has been described above, the present invention is not limited to this example. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

After preparing a vanadium silicocarbide film-forming substrate 2 in which a nitride layer 2a was formed on the surface of the substrate 2b by plasma nitriding, a vanadium silicocarbide film-coated member 1 was prepared in which a vanadium silicocarbide film 3 was formed on the nitride layer 2a of the substrate 2 in which a vanadium silicocarbide film was formed by plasma chemical vapor deposition, and various evaluations were carried out. The plasma processing device with the structure shown in Figure 2 was used as the device for nitriding the substrate 2b and forming the vanadium silicocarbide film 3, and a DC pulse power supply was used as the power source.

The substrate 2b was made by cutting a φ22 mm round bar made of SKH-51, a type of high-speed tool steel, at intervals of 6 to 7 mm, and mirror-polishing the coating surface of the cut bar as shown in Figure 3 to a surface roughness Rzjis of 0.085 μm. The nitride layer 2a and vanadium silicocarbide film 3 were formed on the mirror-polished surface of the substrate 2b.

Example 1
The following describes the method of nitriding the substrate and the method of forming the vanadium silicocarbide film in Example 1. The nitriding conditions and the conditions for forming the vanadium silicocarbide film are also shown in Tables 1 and 2 below. The volumetric flow rates of each gas in the following description are those at 0° C. and 1 atm.

First, the substrate is placed in the chamber of the plasma processing device, and the chamber is evacuated for 60 minutes to reduce the pressure inside the chamber to 25 Pa or less. At this time, the heater installed in the chamber is not operated. The atmospheric temperature inside the chamber is measured with a sheathed thermocouple. Next, the heater is set to 550°C, and the substrate is baked for 60 minutes. After that, the heater is turned off, and the forming device is left for 120 minutes to allow the chamber to cool.

Next, hydrogen gas is supplied into the chamber at a volumetric flow rate of 100 ml/min, and the exhaust rate is adjusted to set the pressure inside the chamber to 100 Pa. The heater temperature is then set to 525°C, and the atmosphere inside the chamber is heated for 30 minutes.

<Nitriding process>
Then, the flow rate of hydrogen gas is set to 80 ml/min, and nitrogen gas and argon gas are supplied into the chamber. In this process, the flow rate of nitrogen gas is set to 20 ml/min, and the flow rate of argon gas is set to 3 ml/min. At this time, the total pressure in the chamber is maintained at 58 Pa by adjusting the exhaust rate. The nitrogen partial pressure/hydrogen partial pressure, which is the partial pressure ratio of the nitrogen partial pressure and the hydrogen partial pressure in Example 1, was 0.25. Then, the voltage of the pulse power supply is set to 1400 V, the duty ratio is set to 40%, and the DC pulse power supply is operated in a unipolar output format. Here, the hydrogen gas, nitrogen gas, and argon gas are plasmatized between the electrodes by increasing the voltage of the pulse power supply. As a result, nitrogen penetrates from the surface of the substrate, and a nitriding process in which a nitride layer is formed on the surface of the substrate is performed for 120 minutes, and a substrate for forming a vanadium silicocarbide film is obtained.

<Vanadium silicocarbide film formation process>
Next, the volumetric flow rate of vanadium tetrachloride gas as vanadium chloride gas is set to 3 ml/min, the volumetric flow rate of monomethylsilane gas as silicon source gas is set to 4.5 ml/min, the volumetric flow rate of methane gas as hydrocarbon gas is set to 30 ml/min, the volumetric flow rate of hydrogen gas is set to 78 ml/min, and the volumetric flow rate of argon gas is set to 3 ml/min, and each gas is supplied into the chamber of the plasma processing apparatus. In other words, each gas is supplied into the chamber in a state where the flow rate ratio of vanadium chloride gas, silicon source gas, hydrocarbon gas, hydrogen gas, and argon gas is 1:1.5:11.5:26:1. At this time, the exhaust amount is adjusted to set the pressure in the chamber to 58 Pa. Then, the voltage of the pulse power supply is set to 1400 V, and the duty ratio is set to 20%. The power of the pulse power supply at this time was 241 W. As a result, the plasmatized vanadium, silicon, and carbon are adsorbed onto the nitride layer, and a vanadium silicocarbide film containing vanadium, silicon, and carbon is formed on the nitride layer. This state was maintained for 180 minutes, yielding a vanadium silicocarbide film-coated member in which the vanadium silicocarbide film-forming substrate was coated with the vanadium silicocarbide film.

Example 2
A vanadium silicocarbide film-forming substrate was obtained under the same conditions as in Example 1, except that the nitriding time was changed to 60 minutes in the nitriding step of Example 1. In addition, a vanadium silicocarbide film was formed under the same conditions as in Example 1, to obtain a vanadium silicocarbide film-coated member, except that in the vanadium silicocarbide film-forming step, the volumetric flow rate of methane gas was set to 10 ml/min, the volumetric flow rate of hydrogen gas was set to 98 ml/min, the vanadium chloride gas, silicon source gas, hydrocarbon gas, hydrogen gas and argon gas were supplied into the chamber in a flow rate ratio of 1:1.5:4.8:33:1, the power of the pulse power source was set to 364 W, and the duty ratio was set to 40%.

Example 3
A vanadium silicocarbide film was formed under the same conditions as in Example 1 to obtain a vanadium silicocarbide film-coated member, except that in the nitriding treatment step of Example 1, the nitriding treatment time was changed to 240 minutes to obtain a base material for forming a vanadium silicocarbide film.

Example 4
A vanadium silicocarbide film-coated member was obtained by forming the vanadium silicocarbide film under the same conditions as in Example 1, except that in the vanadium silicocarbide film-forming step in Example 1, the formation time of the vanadium silicocarbide film was changed to 315 minutes.

(Example 5)
A vanadium silicocarbide film-coated member 1 was obtained by forming the vanadium silicocarbide film under the same conditions as in Example 1, except that in the vanadium silicocarbide film-forming step in Example 1, the formation time of the vanadium silicocarbide film was changed to 420 minutes.

Example 6
In the vanadium silicocarbide film formation process of Example 1, silicon tetrachloride gas was supplied at a volumetric flow rate of 4.5 ml/min instead of monomethylsilane gas supplied as the silicon source gas, the volumetric flow rates of methane gas and hydrogen gas were set to 15 ml/min and 98 ml/min, respectively, vanadium chloride gas, silicon source gas, hydrocarbon gas, hydrogen gas and argon gas were supplied into the chamber in a flow rate ratio of 1:1.5:5:33:1, the power of the pulsed power supply was set to 364 W, the duty ratio was set to 40%, and the formation time of the vanadium silicocarbide film was set to 300 minutes. Except for this, a vanadium silicocarbide film was formed under the same conditions as in Example 1, to obtain a vanadium silicocarbide film-coated member.

(Comparative Example 1)
A vanadium silicocarbide film was formed on the substrate under the same conditions as in Example 6 without carrying out a nitriding treatment, to obtain a vanadium silicocarbide film-coated member.

Next, the state of formation of the nitride layer was confirmed and the surface roughness Rzjis of the nitride layer was measured for the test pieces of the substrate for forming the vanadium silicocarbide film of Examples 1 to 6 and the test pieces of the substrate of the comparative example that was not subjected to nitriding treatment. In addition, the nitriding depth was measured for the test pieces of the substrate for forming the vanadium silicocarbide film of Examples 1 and 3 to 6.

<Confirmation of the nitride layer formation state>
The test piece was cut perpendicular to the surface, the cross section was polished with emery paper, and the polished surface was mirror-finished with a buff. Then, based on the nitric acid alcohol method (Nital method) specified in JIS G 0562, nitric acid and ethanol were mixed, and the test piece was immersed in the resulting 3% nitric acid etching solution for 5 minutes. Thereafter, the cross section of the test piece was observed at a magnification of 1000 times using a metal (optical) microscope, and for test pieces in which the black colored part could be visually recognized in the microscope image, it was determined that a diffusion layer was formed in the nitrided layer, and it was recorded as "present" in Table 3, and when the black part could not be visually recognized, it was recorded as "absent". In addition, for test pieces in which the white colored part could be visually recognized in the microscope image, it was determined that a compound layer was formed in the nitrided layer, and it was recorded as "present" in Table 3, and when the white part could not be visually recognized, it was recorded as "absent".

<Nitriding depth measurement>
The substrate hardness of the test piece was measured, and the nitriding depth (the distance from the surface of the nitrided layer to the position where the hardness is the substrate hardness x 1.15 HV) was measured. The measurement results are shown in Table 3. The substrate hardness value was determined by polishing and mirror finishing the cut surface of the test piece on which the nitrided layer was formed, and then performing a Vickers hardness test with a load of 25 gf using a micro Vickers hardness tester in accordance with the provisions of JIS G 0562. A hardness transition curve was created from the results, and the value at the point where the hardness value converged on the transition curve was used.

<Surface roughness measurement>
A 3D laser microscope (Keyence VK-X120) was used to measure the surface roughness. After obtaining a 0.2 mm x 1.2 mm laser microscope image with an objective lens magnification of 50 times, the surface roughness Rzjis of the nitrided layer was measured using the multiple line roughness measurement function of the multi-file analysis application attached to the microscope. Then, 15 line profiles were obtained in the long side direction of the test piece, and the surface roughness Rzjis obtained from each line profile was averaged to obtain the surface roughness Rzjis value. The results of measuring the surface roughness Rzjis of the nitrided layer of the test pieces of the vanadium silicocarbide film-forming substrates of Examples 1 to 3 and the surface roughness Rzjis of the test pieces of the substrate of Comparative Example 1 that was not subjected to nitriding treatment are shown in Table 3.

Next, the vanadium silicocarbide film-coated members of Examples 1 to 6 and Comparative Example 1 were subjected to thickness measurement of the vanadium silicocarbide film, composition analysis of the vanadium silicocarbide film, scratch testing, hardness measurement, heat resistance evaluation, and friction evaluation testing (ball-on-disk testing).

<Film thickness measurement>
The thickness of the vanadium silicocarbide film formed on the substrate was measured by cutting the test piece vertically, mirror-polishing the cut surface, observing the cut surface with a metallurgical microscope at a magnification of 1000 times, and calculating based on the observed image information. The measurement results are shown in Table 3.

<Composition analysis>
The analytical conditions are as follows. The measurement results are shown in Table 3.
Measuring device: EPMA (JXA-8530F manufactured by JEOL Ltd.)
Measurement mode: semi-quantitative analysis Acceleration voltage: 15 kV
Irradiation current: 1.0×10 ^-7 A
Beam shape: Circle Beam diameter setting value: 50 μm
Spectroscopic crystal: LDE6H, TAP, LDE5H, PETH, LIFH, LDE1H

In addition, when the thickness of the vanadium silicocarbide film is 1 μm or less, the EPMA measurement results include the influence of the component composition of the substrate. Therefore, when calculating the composition analysis of a thin vanadium silicocarbide film, it is necessary to perform an EPMA measurement of only the substrate in advance, and subtract the vanadium element concentration, silicon element concentration, carbon element concentration, and chlorine element concentration derived from the substrate from the EPMA measurement results after the formation of the vanadium silicocarbide film.

<Scratch test>
The adhesion between the substrate and the vanadium silicocarbide film was evaluated using a scratch tester (Revetest manufactured by CSM). The scratch test was performed using a conical diamond indenter with a tip curvature of 100 μm, with a minimum load of 1 N, a maximum load of 100 N, a load speed of 100 N/min, a scratch speed of 5 mm/min, and a scratch distance of 5 mm. The critical load, which is the load at which the vanadium silicocarbide film around the contact point between the indenter and the test piece was broken, that is, the load at which the vanadium silicocarbide film peeled off from the substrate, was measured, and the adhesion between the substrate and the vanadium silicocarbide film was evaluated based on this critical load. The larger the critical load in the scratch test, the more difficult it is for the vanadium silicocarbide film to peel off from the substrate, indicating that the adhesion between the substrate and the vanadium silicocarbide film is high. Note that if the thickness of the vanadium silicocarbide film is within the range of 0.5 to 5.0 μm, the variation in the scratch test results due to differences in film thickness becomes negligibly small.

<Hardness measurement>
The nanoindentation method is carried out using Fischer Instruments' FISCHER SCOPE (registered trademark) H100C. Specifically, a Berkovich-type diamond indenter is pressed into the test piece with a maximum pressing load of 3 mN, and the pressing depth is continuously measured. From the measurement data of the pressing depth obtained, the Martens hardness and the Vickers hardness converted from the Martens hardness are calculated using Fisher Instruments' software "Product name: WIN-HCU (registered trademark)". The calculated Vickers hardness is displayed on the screen of the measuring device, and this value is treated as the hardness of the film at the measurement point. In this example, the Vickers hardness of any 20 points on the outermost surface of each test piece is obtained, and the average value of the obtained hardness is taken as the Vickers hardness of the film. The measurement results are shown in Table 3.

<Heat resistance evaluation>
First, the surface hardness of the test piece is measured at room temperature (25°C). Next, the test piece is placed in a heat treatment furnace and heated to the target temperature over 60 minutes. Then, the test piece is held at the target temperature for another 60 minutes and then allowed to cool for 120 minutes or more. All of these processes are performed in an air atmosphere. After cooling, the surface hardness of the test piece is measured again at room temperature (25°C). The target temperature during heat treatment is set in 100°C increments in the range from room temperature to 1000°C, and one test piece is prepared for each target temperature and a heat treatment test is performed. The maximum target temperature at which the surface hardness after heat treatment/surface hardness before heat treatment is ≧0.75 is determined as the heat resistance temperature for that film type and film formation conditions.

<Friction evaluation test (ball-on-disk test)>
The ball-on-disk tester used was a "Tribometer" manufactured by CSM Instruments. The disks were test pieces of the vanadium silicocarbide film-coated members of Examples 1 to 3, 5, and Comparative Example. A ball made of carbon steel S45C and having a diameter of 6 mm was used as the ball to be in contact with the disk. As shown in FIG. 4, the ball was brought into contact with the disk under an environment of 23 to 24°C and 21% humidity, and the disk was rotated so that the sliding speed was 0.167 m/s while applying a load of 5 N to the ball. The contact point between the ball and the disk was a point with a radius of 6 mm from the center of the disk. The friction coefficient between the disk and the ball when the sliding distance between the disk and the ball reached 100 m was taken as the measured value of the friction coefficient of the vanadium silicocarbide film formed on the substrate.

(summary)
In view of the results of Examples 1 to 6 and Comparative Example, it was found that the adhesion was improved by forming a vanadium silicocarbide film on a vanadium silicocarbide film-forming substrate having a nitride layer with a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less. A comparison of Examples 1, 3 to 6 with Example 2 revealed that a vanadium silicocarbide film-coated member with higher adhesion could be obtained by setting the surface roughness Rzjis of the nitride layer to 0.4 μm or more.

Comparing Examples 1 and 3 to 6 with Example 2, it was found that the adhesion was further improved by satisfying the following formula (1).
(carbon element concentration−vanadium element concentration−silicon element concentration)≧25 at% (1)

Comparing Examples 1 and 5 with Examples 2 and 3, it was found that the coefficient of friction between the vanadium silicocarbide film coated member and the mating member in contact with it was reduced by satisfying the following formula (2).
(carbon element concentration−vanadium element concentration−silicon element concentration)≧30 at% (2)

Comparing Examples 2, 3, and 6 with Examples 1, 4, and 5, it was found that the hardness of the vanadium silicate film was increased by satisfying the following formula (3).
(carbon element concentration−vanadium element concentration−silicon element concentration)≦36 at% (3)

Comparing Examples 1, 4, and 5 with Example 6, it was found that the heat resistance of the vanadium silicate film was improved by satisfying the following formula (4).
Silicon element concentration/(vanadium element concentration+silicon element concentration)>0.7 (4)

The vanadium silicocarbide film-forming substrate and vanadium silicocarbide film-coated member of the present invention can be suitably used as a substrate and vanadium silicocarbide film-coated member for forming vanadium silicocarbide films used in dies, cutting tools, gear cutting tools, forging tools, automotive parts, and the like that are used under conditions of high surface pressure.

Reference Signs List 1 Vanadium silicocarbide film-coated member 2 Substrate for forming vanadium silicocarbide film 2a Nitride layer 2b Substrate 3 Vanadium silicocarbide film 10 Plasma treatment device 11 Chamber 12 Anode 13 Cathode 14 Pulse power source 15 Gas supply pipe 16 Gas exhaust pipe

Claims (19)

A substrate;
A nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less formed on the surface of the base material;
a vanadium silicocarbide film formed on the nitride layer;
the vanadium silicocarbide film contains vanadium, silicon, and carbon, and the sum of the vanadium element concentration, the silicon element concentration, and the carbon element concentration in the film is 90 at % or more;
The vanadium silicocarbide film-coated member has a vanadium element concentration of 3 to 15 at %, a silicon element concentration of 15 to 30 at %, and a carbon element concentration of 60 to 80 at % . A substrate;
A nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less formed on the surface of the base material;
a vanadium silicocarbide film formed on the nitride layer;
the vanadium silicocarbide film contains vanadium, silicon, and carbon, and the sum of the vanadium element concentration, the silicon element concentration, and the carbon element concentration in the film is 90 at % or more;
A vanadium silicocarbide film-coated member that satisfies the following formula (1):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≧25 at% (1) A substrate;
A nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less formed on the surface of the base material;
a vanadium silicocarbide film formed on the nitride layer;
the vanadium silicocarbide film contains vanadium, silicon, and carbon, and the sum of the vanadium element concentration, the silicon element concentration, and the carbon element concentration in the film is 90 at % or more;
A vanadium silicocarbide film-coated member that satisfies the following formula (2):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≧30 at% (2) A substrate;
A nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less formed on the surface of the base material;
a vanadium silicocarbide film formed on the nitride layer;
the vanadium silicocarbide film contains vanadium, silicon, and carbon, and the sum of the vanadium element concentration, the silicon element concentration, and the carbon element concentration in the film is 90 at % or more;
A vanadium silicocarbide film-coated member that satisfies the following formula (3):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≦36 at % (3) A substrate;
A nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less formed on the surface of the base material;
a vanadium silicocarbide film formed on the nitride layer;
the vanadium silicocarbide film contains vanadium, silicon, and carbon, and the sum of the vanadium element concentration, the silicon element concentration, and the carbon element concentration in the film is 90 at % or more;
A vanadium silicocarbide film-coated member satisfying the following formula (4):
The silicon element concentration/(the vanadium element concentration+the silicon element concentration)>0.7 (4) The vanadium silicocarbide film-coated member according to any one of claims 1 to 5 , wherein the surface roughness Rzjis of the nitride layer is 0.25 µm or more. The vanadium silicocarbide film-coated member according to any one of claims 1 to 5 , wherein the surface roughness Rzjis of the nitride layer is 0.4 µm or more. The vanadium silicocarbide film-coated member according to any one of claims 1 to 7 , wherein the substrate is a steel material. a nitriding process for forming a nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less on a surface of the substrate;
a vanadium silicocarbide film forming step of forming a vanadium silicocarbide film on the nitride layer formed in the nitriding treatment step, the vanadium silicocarbide film containing vanadium, silicon and carbon, and having a total vanadium element concentration, silicon element concentration and carbon element concentration of 90 at % or more in the film ,
%。 Vanadium silicocarbide film-coated member of the present invention, wherein the vanadium element concentration is 3 to 15 at %, the silicon element concentration is 15 to 30 at %, and the carbon element concentration is 60 to 80 at % . a nitriding process for forming a nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less on a surface of the substrate;
a vanadium silicocarbide film forming step of forming a vanadium silicocarbide film on the nitride layer formed in the nitriding treatment step, the vanadium silicocarbide film containing vanadium, silicon and carbon, and having a total vanadium element concentration, silicon element concentration and carbon element concentration of 90 at % or more in the film,
A method for producing a vanadium silicocarbide film-coated member, which satisfies the following formula (1):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≧25 at% (1) a nitriding process for forming a nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less on a surface of the substrate;
a vanadium silicocarbide film forming step of forming a vanadium silicocarbide film on the nitride layer formed in the nitriding treatment step, the vanadium silicocarbide film containing vanadium, silicon and carbon, and having a total vanadium element concentration, silicon element concentration and carbon element concentration of 90 at % or more in the film,
A method for producing a vanadium silicocarbide film-coated member, which satisfies the following formula (2):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≧30 at% (2) a nitriding process for forming a nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less on a surface of the substrate;
a vanadium silicocarbide film forming step of forming a vanadium silicocarbide film on the nitride layer formed in the nitriding treatment step, the vanadium silicocarbide film containing vanadium, silicon and carbon, and having a total vanadium element concentration, silicon element concentration and carbon element concentration of 90 at % or more in the film,
A method for producing a vanadium silicocarbide film-coated member, which satisfies the following formula (3):
(the carbon element concentration−the vanadium element concentration−the silicon element concentration)≦36 at % (3) a nitriding process for forming a nitride layer having a surface roughness Rzjis of 0.2 μm or more and 1.0 μm or less on a surface of the substrate;
a vanadium silicocarbide film forming step of forming a vanadium silicocarbide film on the nitride layer formed in the nitriding treatment step, the vanadium silicocarbide film containing vanadium, silicon and carbon, and having a total vanadium element concentration, silicon element concentration and carbon element concentration of 90 at % or more in the film,
A method for producing a vanadium silicocarbide film-coated member, which satisfies the following formula (4):
The silicon element concentration/(the vanadium element concentration+the silicon element concentration)>0.7 (4) The method for producing a vanadium silicocarbide film-coated member according to any one of claims 9 to 13 , wherein the surface roughness Rzjis of the nitride layer is 0.25 µm or more. The method for producing a vanadium silicocarbide film-coated member according to any one of claims 9 to 13 , wherein the surface roughness Rzjis of the nitride layer is 0.4 µm or more. The method for producing a vanadium silicocarbide film-coated member according to any one of claims 9 to 15 , wherein in the nitriding treatment step, the substrate is nitrided by converting hydrogen gas and nitrogen gas into plasma. The method for producing a vanadium silicocarbide film-coated member according to any one of claims 9 to 16 , wherein the substrate is a steel material. 18. The method for producing a vanadium silicocarbide film-coated member according to claim 9 , wherein in the vanadium silicocarbide film-forming step, vanadium chloride gas, a silicon source gas, a hydrocarbon gas and a hydrogen gas are supplied, and the vanadium silicocarbide film is formed by a plasma chemical vapor deposition method. 19. The method for producing a vanadium silicocarbide film-coated member according to claim 18, wherein in the vanadium silicocarbide film forming step, argon gas is further supplied, and a flow rate ratio of the vanadium chloride gas, the silicon source gas, the hydrocarbon gas, the hydrogen gas and the argon gas is 1 :0.25-2:3-20:20-35:0.5-2.

Images