Method for depositing W / WCx composite coating on stainless steel surface and product thereof

Abstract

The invention relates to the technical field of surface engineering, in particular to a method for depositing a W / WCx coating on the surface of stainless steel and a stainless steel product prepared through the method. The method comprises the following steps: S1, depositing a metal transition layer on the surface of a stainless steel substrate; s2, performing diffusion heat treatment on the stainless steel substrate deposited with the metal transition layer in inert gas at 550-800 DEG C; s3, a pure tungsten layer is deposited on the surface of the metal transition layer obtained after diffusion heat treatment; and S4, depositing a W / WCx composite coating on the surface of the pure tungsten layer. The metal composite coating is deposited after the plating layer is subjected to diffusion heat treatment, the surface hardness of the stainless steel can be remarkably improved, and the hardness value of the stainless steel can be four times or above that of traditional stainless steel; the binding force of the metal transition layer and the stainless steel substrate is larger than 120 MPa, the tungsten-containing coating can be effectively prevented from cracking, and the risk of coating stripping is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of surface engineering, in particular to a method for depositing W / WC on the surface of stainless steel. x Composite coating method and products thereof. Background Art

[0002] Tungsten Carbide (WC x ) The coating has many advantages such as strong oxidation resistance, high hardness, good wear resistance and corrosion resistance, and small thermal expansion coefficient. More importantly, by adjusting W and WC x The ratio of the phases can achieve different hardness and toughness matching, which makes it have a wide range of application prospects in various fields. x Composite coatings can effectively improve wear resistance and corrosion resistance, thereby increasing the service life of stainless steel, reducing maintenance costs and replacement frequency, and improving overall engineering efficiency and reliability.

[0003] However, due to WC x The incompatibility of chemical composition with stainless steel surface and the large difference in physical properties make it difficult to prepare WC with good adhesion directly on stainless steel substrate. x At present, W / WC coating is mainly prepared on the surface of stainless steel. x The composite coating method involves preparation methods such as laser cladding, thermal spraying, chemical vapor deposition (CVD), etc. Laser cladding and thermal spraying technology are difficult to form a uniform coating on the surface of complex-shaped structural parts. CVD technology builds a protective layer consisting of pure tungsten layer and tungsten carbide layer on the surface of complex-shaped structural parts by layer-by-layer deposition. This technology has strong wrapping ability and can be evenly coated even on complex-shaped components. Traditional CVD deposition of WC on the surface of stainless steel x The coating is usually prepared on the stainless steel surface firstly, and then the WC x However, the internal stress caused by the difference in thermal expansion coefficients between the coating and the substrate makes the metal (M) / WC prepared by this method x Composite coatings are prone to cracking or peeling off of the coating and substrate.

[0004] Patent CN107130227B discloses a method for preparing WC by atmospheric pressure vapor deposition. xA method for preparing a coating, wherein a tungsten transition layer is first deposited on a substrate, and then a tungsten hexafluoride / dimethyl ether ratio is controlled to deposit ultrafine W2C grains and amorphous materials with a particle size of 3 to 5 nm on the tungsten transition layer, and the coating prepared by the method effectively improves the coating hardness and interlayer bonding strength; Patent application CN117660916A discloses a method for preparing a thick tungsten coating, wherein the method comprises chemical vapor deposition of activated n-propylamine, tungsten hexafluoride and hydrogen on the surface of a substrate, wherein the chemical vapor deposition comprises a plurality of chemical vapor deposition stages performed in sequence, and an annealing stage is provided after each chemical vapor deposition stage, so as to prepare a thick tungsten coating; the prepared thick tungsten coating is composed of a microscopic group of fine columnar crystals with an average width of ≤50 μm, and the width thereof remains substantially unchanged along the growth direction, thereby ensuring the excellent thermal conductivity and mechanical properties of the prepared thick tungsten coating. Currently, these methods for preparing coatings all improve the mechanical properties of the coatings and their interlayer bonding strength by improving the microstructure or internal stress of the coatings themselves. The coatings prepared using these methods cannot guarantee the bonding strength between the transition layer and the substrate, thus becoming a limiting link for the coatings to exhibit excellent performance.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] In order to solve the problem of stainless steel substrate and W / WC x In order to solve the problem of poor bonding strength of the composite coating and improve the mechanical properties of the coating, the present invention provides a method for depositing a metal composite coating on a stainless steel surface and a product thereof, so as to increase the service life of stainless steel products coated with the metal composite coating.

[0007] Based on this, the present invention has the following technical solutions: In the first aspect, the present invention provides a method for depositing W / WC on a stainless steel surface. x A composite coating method comprising: S1: depositing a metal transition layer on the surface of the stainless steel substrate; S2: subjecting the stainless steel substrate after the metal transition layer is deposited to diffusion heat treatment in an inert gas at 550-800°C; S3: depositing a pure tungsten layer on the surface of the metal transition layer obtained after the diffusion heat treatment; S4: Depositing W / WC on the surface of the pure tungsten layer x Composite coating; W / WC x Represents a composite coating of tungsten and tungsten carbide; wherein x represents the atomic ratio of carbon to tungsten, and the value of x is 0.3~1.

[0008] In the present invention, WC xstands for tungsten carbide, where x represents the atomic ratio of carbon to tungsten, specifically 0.3~1, and can be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1, etc.; for example, WC x Is a mixture of W2C and W3C or W2C.

[0009] The present invention can form a good metallurgical bond between the transition layer and the stainless steel substrate by first plating a metal transition layer on the stainless steel substrate and performing the diffusion heat treatment; then depositing a pure tungsten layer, and then depositing W / WC x Composite coating, thereby obtaining a film with higher membrane-base bonding strength and microhardness, to solve the problem of insufficient adhesion between the existing coating and the stainless steel substrate, thereby increasing the service life of stainless steel parts.

[0010] In the present invention, the diffusion heat treatment of the stainless steel plated with the transition metal layer is carried out before deposition in the deposition furnace, which saves the heat treatment equipment and simplifies the preparation process; during the diffusion heat treatment process, the internal stress of the material is released, and the atoms at the interface chemically react to form a metal compound layer, thereby ensuring good metallurgical bonding.

[0011] In specific implementation, the temperature of the diffusion heat treatment can be any value such as 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, etc., or a numerical range with any two of the above values ​​as endpoints.

[0012] In the present invention, S1 also includes plating pretreatment, which includes mechanical polishing, oil removal, ultrasonic cleaning, mixed acid oxide film removal, pure water washing, drying and other processes on the stainless steel substrate in sequence.

[0013] In the specific implementation process, those skilled in the art can deposit the metal transition layer on the surface of the stainless steel substrate by any deposition method including chemical plating, electroplating, hot dip plating, magnetron sputtering, and PVD, which is not limited here.

[0014] Preferably, the raw material of the metal transition layer includes one or more of nickel, cobalt, chromium, titanium and titanium alloy.

[0015] Preferably, the raw material of the metal transition layer is titanium or a titanium alloy; more preferably, the titanium content of the titanium alloy is above 90 wt %.

[0016] Preferably, the diffusion heat treatment comprises: firstly evacuating the inside of the deposition equipment to a vacuum of 5×10 -2 Pa, and then introduce inert gas to normal pressure, repeat this process at least twice to complete the gas replacement in the deposition equipment. After the replacement is completed, the temperature is raised to 550~800℃ under the condition of passing inert gas for diffusion heat treatment.

[0017] Preferably, the holding time of the diffusion heat treatment is 0.5 to 10 hours.

[0018] In the present invention, the temperature and holding time of the diffusion heat treatment should be adjusted in combination with the specific stainless steel type. Generally speaking, the temperature is controlled at 550-800°C and the time is controlled at 0.5-10h, which can ensure that the nickel plating layer forms a good metallurgical bond with the stainless steel substrate.

[0019] Preferably, the W / WC x The carbon content in the composite coating is 10~40 at%.

[0020] The present invention finds that the hardness of the coating can be controlled by controlling the carbon content in the coating, thereby meeting different requirements of products in different application fields; when the carbon content is within the above range, the hardness is higher and the toughness is better, which can improve the comprehensive mechanical properties of the coating.

[0021] Preferably, the W / WC x The deposition thickness of the composite coating is 20-130 μm; more preferably 50-120 μm, for example, it can be any value such as 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm or 120 μm, or a numerical range with any two of the above values ​​as endpoints.

[0022] Preferably, the thickness of the metal transition layer is 0.2~20μm, more preferably 0.2~5μm, for example, it can be any value such as 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm or 5μm, or a numerical range with any two of the above values ​​as endpoints.

[0023] And / or, the thickness of the pure tungsten layer is 2-8 μm, for example, it can be any value such as 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm or 2 μm, or a numerical range with any two of the above values ​​as endpoints.

[0024] Preferably, S3 comprises: introducing WF6 and H2 at a flow ratio of 1:(3-6) at 580-650°C. For example, the temperature here can be any value such as 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, 640°C, 650°C, or a numerical range with any two of the above values ​​as endpoints.

[0025] Preferably, S4 includes: introducing WF6, carbon source gas C2H6O and H2 at 600-750°C; wherein the flow ratio of WF6 to H2 is 1:(3-5), and the flow ratio of carbon source gas C2H6O to H2 is (0.1-0.4):1. For example, the flow ratio of WF6 to H2 can be any ratio of 1:3, 1:4, 1:5, or a ratio range in which any two of the above ratios are endpoints; the flow ratio of carbon source gas C2H6O to H2 can be any ratio of 0.1:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, or a ratio range in which any two of the above ratios are endpoints.

[0026] In the present invention, the reaction temperature in S4 can be any value such as 600°C, 610°C, 620°C, 630°C, 640°C, 650°C, 660°C, 670°C, 680°C, 690°C, 700°C, 710°C, 720°C, 730°C, 740°C or 750°C, or a numerical range with any two of the above values ​​as endpoints.

[0027] In a second aspect, the present invention provides a stainless steel product, which is produced by the above method.

[0028] The present invention performs diffusion heat treatment on the coating and then deposits a pure tungsten layer and W / WC x The composite coating can significantly increase the surface hardness of stainless steel and the bonding strength between the metal transition layer and the stainless steel substrate, and can effectively prevent the tungsten-containing coating from cracking and avoid the risk of peeling. The hardness of general stainless steel is 150~400HV, while the hardness of the wear-resistant and corrosion-resistant stainless steel produced by the present invention can be significantly improved, reaching more than 4 times the hardness of general stainless steel. The bonding strength between the metal transition layer and the stainless steel substrate is greater than 120MPa, which greatly improves its service life. At the same time, the diffusion heat treatment and the deposition of the film are integrated in the same deposition furnace, with flexible process, simple steps, low cost, and suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 The W / WC deposited on the stainless steel substrate in Example 1 provided by the present invention x -Schematic diagram of the cross-sectional structure of the workpiece with W-Ni composite coating.

[0031] Figure 2 is W / WC in Example 3 provided by the present inventionx XRD phase diagram of the coating.

[0032] Figure 1 Description of the drawings: 101 is a stainless steel substrate, 102 is a transition metal layer, 103 is a pure tungsten layer, 104 is a W / WC x Composite coating. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Unless otherwise specified, the various raw materials used in the examples and comparative examples are commercially available conventional raw materials, and the technical means used are conventional means well known to those skilled in the art.

[0035] Example 1 This embodiment provides a W / WC deposition on the surface of stainless steel. x -W-Ni metal composite coating method (in this embodiment, W / WC is deposited on the stainless steel substrate) x -W-Ni composite coating workpiece cross-sectional structure diagram is shown in Figure 1 ), including the following steps: (1) Commercially available 310S stainless steel was used as the substrate and pretreated, including mechanical polishing, degreasing, ultrasonic cleaning in acetone, mixed acid film removal, pure water ultrasonic cleaning, pure water rinsing, drying, etc., and then chemically plated with Ni. The coating thickness was controlled at 2.4 μm.

[0036] (2) placing the stainless steel substrate plated with the nickel layer into a deposition furnace for diffusion heat treatment, wherein the diffusion heat treatment comprises: first evacuating the deposition furnace to a vacuum of 5×10 -2 Then, the furnace temperature was raised to 800°C in an argon atmosphere and kept at this temperature for 2.5 h.

[0037] (3) Depositing a pure tungsten layer. The specific operation includes: after the diffusion heat treatment is completed, the furnace temperature is lowered to 600°C, and the furnace is vacuumed to 5×10 -2 Hydrogen was introduced below Pa and kept at 600℃ for 1h, during which the hydrogen flow rate was controlled at 1.2L / min. After the insulation, WF6 was introduced at a flow rate of 0.38L / min for 10min, and finally a 15μm pure tungsten coating was obtained.

[0038] (4) Continue to deposit W / WC on the basis of the pure tungsten layer x The coating was prepared by controlling the furnace temperature to 600 °C, the WF6 flow rate to 0.38 L / min, the C2H6O flow rate to 0.3 L / min, the hydrogen flow rate to 1.2 L / min, and the deposition time to 2 h to obtain W / WC x The thickness of the composite coating is 85 μm, and the carbon content is about 12 at%.

[0039] W / WC of this embodiment x The coating represents a composite coating of tungsten and tungsten carbide; wherein x is 0.3~0.5.

[0040] Example 2 This embodiment provides a method for depositing a metal composite coating on a stainless steel surface, comprising the following steps: (1) Commercially available 310S stainless steel was used as the substrate and pretreated, including mechanical polishing, degreasing, hot water washing, cold water washing, mixed acid film removal, cold water washing, activation, hot water washing, etc., and then chemical nickel plating was performed. The coating thickness was controlled at 2.4 μm.

[0041] (2) placing the stainless steel substrate plated with the nickel layer in a deposition furnace for diffusion heat treatment, wherein the diffusion heat treatment comprises: first evacuating the deposition furnace to a vacuum of 5×10 -2 Then, the furnace temperature was raised to 800°C in an argon atmosphere and kept at this temperature for 2.5 hours to allow the nickel-plated layer to fully diffuse into the stainless steel substrate.

[0042] (3) Depositing a pure tungsten layer. The specific operation includes: after the diffusion heat treatment is completed, the furnace temperature is lowered to 600°C, and the furnace is vacuumed to 5×10 -2 Hydrogen was introduced below Pa and kept at 600℃ for 1h, during which the hydrogen flow rate was controlled at 1.2L / min. After the insulation, WF6 was introduced at a flow rate of 0.38L / min for 10min, and finally a 15μm pure tungsten coating was obtained.

[0043] (4) Continue to deposit W / WC on the basis of the pure tungsten layer x Coating, control the furnace temperature to 600℃, WF6 flow rate to 0.38L / min, C2H6O flow rate to 0.36L / min, hydrogen flow rate to 1.5L / min, deposition time to 2h, and obtain W / WC x The coating thickness is 97 μm, and the carbon content is about 17 at%.

[0044] W / WC of this embodiment x The coating represents a composite coating of tungsten and tungsten carbide; wherein x is 0.3~0.5.

[0045] Example 3 This embodiment provides a method for depositing a metal composite coating on a stainless steel surface, comprising the following steps: (1) Commercially available 17-4PH stainless steel was used as a substrate and pretreated, including mechanical polishing, ultrasonic cleaning in acetone, ultrasonic cleaning in anhydrous ethanol, and drying. Then, a Ti film was deposited by magnetron sputtering with a coating thickness of 0.34 μm.

[0046] (2) placing the stainless steel substrate coated with the titanium layer in a deposition furnace for diffusion heat treatment, wherein the diffusion heat treatment comprises: first evacuating the deposition furnace to a vacuum of 5×10 -2 Then, the furnace temperature was raised to 550°C in an argon atmosphere and kept at this temperature for 4 h.

[0047] (3) Depositing a pure tungsten layer. The specific operation includes: after the diffusion heat treatment is completed, the furnace temperature is raised to 580°C, and the furnace is vacuumed to 5×10 -2 Hydrogen was introduced below Pa and kept at 580℃ for 1h, during which the hydrogen flow rate was controlled at 0.9L / min. After the insulation, WF6 was introduced at a flow rate of 0.28L / min for 12min, and finally a 10μm pure tungsten coating was obtained.

[0048] (4) Continue to deposit W / WC on the basis of the pure tungsten layer x Coating, control the furnace temperature to 620℃, WF6 flow rate to 0.38L / min, C2H6O flow rate to 0.43L / min, hydrogen flow rate to 1.8L / min, deposition time to 1.5h, and obtain W / WC x The coating thickness is 113 μm, and the carbon content is about 24 at%.

[0049] W / WC of this embodiment x The coating represents a composite coating of tungsten and tungsten carbide; where x is 0.5; W / WC x The XRD phase diagram of the coating is shown in Figure 2 .

[0050] Example 4 This embodiment provides a W / WC deposition on the surface of stainless steel. x The composite coating method comprises the following steps: (1) Commercially available 310S stainless steel was used as the substrate and pretreated, including mechanical polishing, degreasing, hot water washing, cold water washing, mixed acid defilming, cold water washing, activation, hot water washing, etc., and then a Ti film was deposited by magnetron sputtering with a thickness of 80 nm.

[0051] (2) placing the stainless steel substrate coated with the Ti layer in a deposition furnace for diffusion heat treatment, wherein the diffusion heat treatment comprises: first evacuating the deposition furnace to a vacuum of 5×10 -2 Then, the furnace temperature was raised to 550°C in an argon atmosphere and kept at this temperature for 4 h.

[0052] (3) Depositing a pure tungsten layer. The specific operation includes: after the diffusion heat treatment is completed, the furnace temperature is raised to 600°C, and the furnace is evacuated to 5×10 -2 Hydrogen was introduced below Pa and kept at 600℃ for 1h, during which the hydrogen flow rate was controlled at 1.2L / min. After the insulation, WF6 was introduced at a flow rate of 0.38L / min for 10min, and finally a pure tungsten coating with a thickness of 15μm was obtained.

[0053] (4) Continue to deposit W / WC on the basis of the pure tungsten layer x Coating, control the furnace temperature to 600℃, WF6 flow rate to 0.38L / min, C2H6O flow rate to 0.36L / min, hydrogen flow rate to 1.5L / min, deposition time to 2h, and obtain W / WC x The composite coating has a thickness of 97 μm and a carbon content of about 17 at%.

[0054] W / WC of this embodiment x The coating represents a composite coating of tungsten and tungsten carbide; wherein x is 0.3~0.5.

[0055] Example 5 This embodiment provides a W / WC deposition on the surface of stainless steel. x The composite coating method comprises the following steps: (1) Commercially available 310S stainless steel was used as the substrate and pretreated, including mechanical polishing, degreasing, hot water washing, cold water washing, mixed acid defilming, cold water washing, activation, hot water washing, etc. Then, a Co film was deposited by magnetron sputtering with a coating thickness of 80 nm.

[0056] (2) placing the stainless steel substrate coated with the Co layer in a deposition furnace for diffusion heat treatment, wherein the diffusion heat treatment comprises: first evacuating the deposition furnace to a vacuum of 5×10 -2 Then, the furnace temperature was raised to 600°C in an argon atmosphere and kept at this temperature for 2 h to allow the Co-plated layer to fully diffuse into the stainless steel substrate.

[0057] (3) Depositing a pure tungsten layer. The specific operation includes: after the diffusion heat treatment is completed, the furnace is evacuated to a vacuum of 5×10 - 2Hydrogen was introduced below Pa and kept warm for 1 hour, during which the hydrogen flow rate was controlled at 1.2L / min. After the insulation, WF6 was introduced at a flow rate of 0.38L / min for 10 minutes, and finally a 15μm pure tungsten coating was obtained.

[0058] (4) Continue to deposit W / WC on the basis of the pure tungsten layer x Coating, control the furnace temperature to 600℃, WF6 flow rate to 0.38L / min, C2H6O flow rate to 0.2L / min, hydrogen flow rate to 1.5L / min, deposition time to 2h, and obtain W / WC x The coating thickness is 97 μm, and the carbon content is 17 at%.

[0059] W / WC of this embodiment x The coating represents a composite coating of tungsten and tungsten carbide; wherein x is 0.3~0.5.

[0060] Example 6 This embodiment provides a method for depositing a metal composite coating on a stainless steel surface, which is different from Embodiment 3 only in that the metal transition layer is a tungsten-titanium alloy, wherein the mass ratio of tungsten to titanium is 90:10.

[0061] W / WC of this embodiment x The coating represents a composite coating of tungsten and tungsten carbide; wherein x is 0.3~0.5.

[0062] Example 7 This embodiment provides a method for depositing a tungsten and tungsten carbide composite coating on a stainless steel surface, which differs from Embodiment 3 only in that the metal transition layer is a tungsten-titanium alloy, wherein the mass ratio of tungsten to titanium is 70:30.

[0063] W / WC of this embodiment x The coating represents a composite coating of tungsten and tungsten carbide; wherein x is 0.3~0.5.

[0064] Comparative Example 1 This comparative example provides a method for depositing a composite coating on a stainless steel surface, which differs from Example 1 only in that a pure tungsten layer and a composite coating of tungsten and tungsten carbide are directly deposited on a stainless steel substrate covered with a transition metal layer, without performing diffusion heat treatment on the intermediate transition layer.

[0065] Comparative Example 2 This comparative example provides a method for depositing a composite coating on a stainless steel surface, which differs from Example 2 only in that a pure tungsten layer and a composite coating of tungsten and tungsten carbide are directly deposited on a stainless steel substrate covered with a transition metal layer, without performing diffusion heat treatment on the intermediate transition layer.

[0066] Comparative Example 3 This comparative example provides a method for depositing a composite coating on a stainless steel surface, which differs from Example 3 only in that the temperature of the diffusion heat treatment is 450°C.

[0067] Comparative Example 4 This comparative example provides a method for depositing a composite coating on a stainless steel surface, which differs from Example 3 only in that the diffusion heat treatment is performed in air.

[0068] Test example The present invention further studies the bonding strength between the transition metal layer and the stainless steel substrate and the W / WC x The microhardness of the composite coating was tested and the results are shown in Table 1.

[0069] Test method: Bonding strength between transition metal layer and stainless steel substrate: tested according to GB5210-2006-T paint and varnish pull-off adhesion test method.

[0070] W / WC x Microhardness of composite coating: carried out according to ASTM-E384-11 Vickers hardness standard test method.

[0071] Table 1

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for depositing W / WC on stainless steel surface x A coating method, characterized in that include: S1: depositing a metal transition layer on the surface of the stainless steel substrate; S2: subjecting the stainless steel substrate after the metal transition layer is deposited to diffusion heat treatment in an inert gas at 550-800°C; S3: depositing a pure tungsten layer on the surface of the metal transition layer obtained after the diffusion heat treatment; S4: Depositing W / WC on the surface of the pure tungsten layer x Composite coating; W / WC x Represents a composite coating of tungsten and tungsten carbide; wherein x represents the atomic ratio of carbon to tungsten, and the value of x is 0.3~1.

2. The method for depositing W / WC on the surface of stainless steel according to claim 1. x A coating method, characterized in that The raw materials in the metal transition layer include one or more of nickel, cobalt, chromium, titanium and titanium alloy.

3. The method for depositing W / WC on the surface of stainless steel according to claim 2 x A coating method, characterized in that The raw material of the metal transition layer is titanium or titanium alloy; the titanium content in the titanium alloy is more than 90wt%.

4. The method for depositing W / WC on the surface of stainless steel according to any one of claims 1 to 3. x A coating method, characterized in that The holding time of the diffusion heat treatment is 0.5 to 10 hours.

5. The method for depositing W / WC on the surface of stainless steel according to any one of claims 1 to 3. x A coating method, characterized in that The carbon content in the composite coating of tungsten and tungsten carbide is 10-40 at%.

6. The method for depositing W / WC on the surface of stainless steel according to any one of claims 1 to 3. x A coating method, characterized in that The deposition thickness of the composite coating of tungsten and tungsten carbide is 20-130 μm.

7. The method for depositing W / WC on the surface of stainless steel according to any one of claims 1 to 3. x A coating method, characterized in that The thickness of the metal transition layer is 0.2-20 μm; and / or the thickness of the pure tungsten layer is 2-8 μm.

8. The method for depositing W / WC on the surface of stainless steel according to any one of claims 1 to 3. x A coating method, characterized in that S3 includes: WF6 and H2 at a flow ratio of 1: (3-6) at 580-650°C.

9. The method for depositing W / WC on the surface of stainless steel according to any one of claims 1 to 3. x A coating method, characterized in that S4 The method comprises: introducing WF6, carbon source gas C2H6O and H2 at 600-750° C.; wherein the flow ratio of WF6 and H2 is 1:(3-5), and the flow ratio of carbon source gas C2H6O and H2 is (0.1-0.4):

1.

10. A stainless steel product, characterized in that: It is prepared by the method described in any one of claims 1 to 9.

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