Anticorrosion, nano black passivation type metal material and its preparation process and application

Abstract

The application relates to the alloy material technical field, in particular to a kind of anticorrosive, nano black passivation type metal material and its preparation process and application.A kind of anticorrosive, nano black passivation type metal material is made of stainless steel powder, surface modification treated tungsten carbide, spherical graphene modified stainless steel powder by powder metallurgy process;The total mass of surface modification treated tungsten carbide and spherical graphene modified stainless steel powder is equal to 0.5-1.0wt% of the mass of anticorrosive, nano black passivation type metal material;The mass ratio of surface modification treated tungsten carbide and spherical graphene modified stainless steel powder is 1:(0.1-5);Surface modification treated tungsten carbide includes matrix tungsten carbide and nano modified metal particles loaded on the surface of matrix tungsten carbide.In the application, the anticorrosive, nano black passivation type metal material meets the salt fog resistance of steel in the electronic industry and does not need subsequent electroplating treatment, the precision of electronic device is relatively good, the product yield is improved, and the product cost is reduced.

Description

[0001] The substrate tungsten carbide is nano tungsten carbide with an average particle size of 50-500 nm; the nano modified metal particles are loaded on the surface of the substrate tungsten carbide by a sol-gel method, and the loading rate of the nano modified metal particles is ≥5 wt%;

[0002] The spherical graphene modified stainless steel powder is prepared by spraying the stainless steel powder and the surface modified graphene; the addition amount of the surface modified graphene is equal to 5-10 wt% of the mass of the spherical graphene modified stainless steel powder; the particle size D 50 of the spherical graphene modified stainless steel powder is ≤35 microns;

[0003] The surface modified graphene comprises substrate graphene and nano modified metal particles loaded on the surface of the substrate graphene, and the loading rate of the nano modified metal particles is ≥5 wt%; the nano modified metal particles at least comprise nano iron particles;

[0004] The surface modified graphene comprises substrate graphene and metal monomers anchored to defect sites of the substrate graphene, and the loading rate of the metal monomers is ≥1 wt%, and the metal monomers at least comprise iron monomers;

[0005] The preparation method of the spherical graphene modified stainless steel powder is as follows:

[0006] S1. After the stainless steel powder and the surface modified graphene are uniformly mixed, they are transferred into a planetary ball mill, tungsten carbide is used as the grinding bead, and dry ball milling is performed at 60-80 rpm for 20-40 min to obtain a mixed alloy powder;

[0007] S2. The mixed alloy powder obtained in S1 is prepared into a spherical alloy powder by an aerosol method, the particle size D 50 of the obtained spherical alloy powder is 5-35 microns, and the tap density is ≥1.75 g / cm 3 ;

[0008] The metal material is coated with a nano passivation coating, the nano passivation coating is prepared from a nano passivation coating material, the nano passivation coating material comprises water-based polyester resin, silane coupling agent, carbon black, and black titanium dioxide nanoparticles, the total mass of the carbon black and the black titanium dioxide nanoparticles accounts for 3-10 wt% of the total mass of the nano passivation coating material; the mass of the silane coupling agent accounts for 0.5-1.0 wt% of the total mass of the nano passivation coating material; and the solid content of the water-based polyester resin is 30-55 wt%.

[0009] Step one, preparation of the surface modified tungsten carbide and the spherical graphene modified stainless steel powder;

[0010] Step two, the surface modified tungsten carbide, spherical graphene modified stainless steel powder prepared in step one is mixed with stainless steel powder according to the ratio, and then transferred to a planetary ball mill, with tungsten carbide as the grinding bead, dry ball milling at 60-80 rpm for 5-15 min to obtain a mixed alloy powder;

[0011] Step three, the mixed alloy powder obtained in step two is placed in a forming mold for hot isostatic pressing treatment, and the hot isostatic pressing parameters are as follows: forming temperature 880-950℃, forming pressure: first pressurized to 120-160MPa at 15-20MPa / s, pressure maintaining for 10-20s, then pressurized to 200-240MPa at 8-10MPa / s, pressure maintaining for 20-30s, then pressurized to 320-350MPa at 4-6MPa / s, pressure maintaining for 20-30s, then pressurized to 450-500MPa at 1-2MPa / s, pressure maintaining for 30-60s, then depressurized to 550-600MPa at 0.5-1MPa / s, pressure maintaining for 30-60s, then depressurized to 280-320MPa at 1-2MPa / s, pressure maintaining for 30-60s, then depressurized to 160-200MPa at 4-8MPa / s, pressure maintaining for 30-60s, finally depressurized to 0MPa at 15-20MPa / s, forming speed is 0.5-5mm / s, cooling to room temperature, grinding burrs to obtain a semi-finished product;

[0012] Step four, the surface of the semi-finished product obtained in step three is subjected to high-energy laser melting treatment, the laser spot temperature is 2880-3000℃, the laser scanning speed is 400-1200mm / s, the spot diameter is 0.04-0.08mm, after high-energy laser melting treatment, quenching+tempering treatment is carried out to obtain a corrosion-resistant metal material, the corrosion-resistant metal material is coated with a 8-20μm thick nano passivation coating by roll coating, and is baked to dry at 150-250℃ to obtain a finished product of corrosion-resistant, nano black passivated metal material. TECHNICAL FIELD

[0013] The present application relates to the technical field of alloy materials, in particular to a corrosion-resistant, nano black passivated metal material and its preparation process and application. BACKGROUND

[0014] At present, in order to prevent steel from being eroded by the external environment and prolong the service life of the whole steel, the surface of the steel is subjected to corrosion prevention treatment. The most popular corrosion prevention treatment method is to electroplate a zinc layer on the surface of the steel. The zinc-plated steel has good corrosion resistance and is widely used in the fields of electronic devices, household appliances, vehicles, ships, mechanical parts, etc.

[0015] The galvanized steel material is tested by GB / T 2423.17 salt spray test for 72H±1H, and different galvanizing processes and thickness and uniformity of the galvanized layer will affect the salt spray resistance of the galvanized steel material. The existing salt spray resistance of the galvanized steel material is less than 73H, and the electronic industry requires the salt spray resistance of the steel material to be greater than or equal to 76H, so that the existing galvanized steel material cannot meet the high salt spray resistance requirement of the electronic industry for electronic devices. In addition, the electronic devices in the electronic industry have high precision and large processing difficulty, and the surface treatment of the steel material by the galvanizing process not only has relatively complex process, but also affects the precision of the electronic device, resulting in a decrease in product yield and an increase in product cost.

[0016] To solve the technical problems of the prior art, the inventors provide a kind of anti-corrosion, nano black passivation type metal material and its preparation process and application. SUMMARY

[0017] To solve the technical problems of the prior art, the inventors provide a kind of anti-corrosion, nano black passivation type metal material and its preparation process and application.

[0018] The anti-corrosion, nano black passivation type metal material provided by the present application is realized by the following scheme:

[0019] The anti-corrosion, nano black passivation type metal material is made of stainless steel powder, surface modified tungsten carbide and spherical graphene modified stainless steel powder by powder metallurgy process; the total mass of the surface modified tungsten carbide and the spherical graphene modified stainless steel powder is equal to 0.5-1.0wt% of the mass of the anti-corrosion, nano black passivation type metal material; the mass ratio of the surface modified tungsten carbide to the spherical graphene modified stainless steel powder is 1:(0.1-5); the surface modified tungsten carbide includes matrix tungsten carbide and nano modified metal particles loaded on the surface of the matrix tungsten carbide, and the nano modified metal particles at least include nano iron particles.

[0020] The anti-corrosion, nano black passivation type metal material provided by the present application meets the salt spray resistance requirement of the steel material in the electronic industry and does not need subsequent electroplating treatment, has relatively good electronic device precision, improves product yield and reduces product cost.

[0021] Preferably, the substrate tungsten carbide is nano tungsten carbide with an average particle size of 50-500 nm; the nano modified metal particles are loaded on the surface of the substrate tungsten carbide by a sol-gel method, and the loading rate of the nano modified metal particles is ≥5 wt%.

[0022] By adopting the technical solution, the compatibility of the nano tungsten carbide and the iron substrate is improved, the surface modified tungsten carbide is uniformly dispersed in the iron substrate, and the overall corrosion resistance and wear resistance are improved.

[0023] Preferably, the spherical graphene modified stainless steel powder is prepared by spraying the stainless steel powder and the surface modified graphene; the addition amount of the surface modified graphene is equal to 5-10 wt% of the mass of the spherical graphene modified stainless steel powder; and the particle size D50 of the spherical graphene modified stainless steel powder is ≤35 microns.

[0024] Preferably, the surface modified graphene comprises substrate graphene and nano modified metal particles loaded on the surface of the substrate graphene, and the loading rate of the nano modified metal particles is ≥5 wt%; the nano modified metal particles at least comprise nano iron particles.

[0025] Preferably, the surface modified graphene comprises substrate graphene and metal monomers anchored to defect sites of the substrate graphene, and the loading rate of the metal monomers is ≥1 wt%; the metal monomers at least comprise iron monomers.

[0026] By adopting the technical solution, the compatibility of the substrate graphene and the iron substrate is improved, the surface modified graphene is uniformly dispersed in the iron substrate, and the overall corrosion resistance, wear resistance and mechanical strength are improved.

[0027] Preferably, the preparation method of the spherical graphene modified stainless steel powder is as follows:

[0028] S1. After the stainless steel powder and the surface modified graphene are uniformly mixed, they are transferred into a planetary ball mill, tungsten carbide is used as a grinding bead, and dry ball milling is performed at 60-80 rpm for 20-40 min to obtain a mixed alloy powder;

[0029] S2. The mixed alloy powder obtained in S1 is used to prepare a spherical alloy powder by an aerosol method, the particle size D50 of the obtained spherical alloy powder is 5-35 microns, and the tap density is ≥1.75 g / cm 50 . 3 .

[0030] By adopting the technical solution, the prepared spherical graphene modified stainless steel powder has good dispersion performance with the stainless steel powder, can improve the dispersion uniformity of the spherical graphene modified stainless steel powder in the iron substrate, and further improve the overall corrosion resistance, wear resistance and mechanical strength.

[0031] Preferably, the total mass of the surface-modified tungsten carbide and the spherical graphene-modified stainless steel powder is equal to 0.7-0.8 wt% of the mass of the corrosion-resistant, nano-black passivated metal material; and the mass ratio of the surface-modified tungsten carbide to the spherical graphene-modified stainless steel powder is 1:(0.5-2).

[0032] By adopting the technical scheme, the salt mist resistance of the steel material in the electronic industry is met, and the overall production cost is reduced.

[0033] The preparation process of the corrosion-resistant, nano-black passivated metal material provided in the present application is realized through the following scheme:

[0034] The preparation process of the corrosion-resistant, nano-black passivated metal material comprises the following steps:

[0035] Step one: preparation of the surface-modified tungsten carbide and the spherical graphene-modified stainless steel powder;

[0036] Step two: the surface-modified tungsten carbide and the spherical graphene-modified stainless steel powder prepared in step one are mixed with the stainless steel powder in a proportion, and then transferred to a planetary ball mill, tungsten carbide is used as the grinding bead, and dry ball milling is performed at 60-80 rpm for 5-15 min to obtain a mixed alloy powder;

[0037] Step three: the mixed alloy powder obtained in step two is placed in a forming mold for hot isostatic pressing treatment, and the hot isostatic pressing parameters are as follows: forming temperature: 880-950℃, forming pressure: first pressurized at 15-20 MPa / s to 120-160 MPa, pressure maintaining for 10-20 s, then pressurized at 8-10 MPa / s to 200-240 MPa, pressure maintaining for 20-30 s, then pressurized at 4-6 MPa / s to 320-350 MPa, pressure maintaining for 20-30 s, then pressurized at 1-2 MPa / s to 450-500 MPa, pressure maintaining for 30-60 s, then pressurized at 0.5-1 MPa / s to 550-600 MPa, pressure maintaining for 30-60 s, then depressurized at 1-2 MPa / s to 280-320 MPa, pressure maintaining for 30-60 s, then depressurized at 4-8 MPa / s to 160-200 MPa, pressure maintaining for 30-60 s, and finally depressurized at 15-20 MPa / s to 0 MPa, forming speed: 0.5-5 mm / s, and cooled to room temperature, and then polished to remove burrs to obtain a semi-finished product;

[0038] Step four: high-energy laser melting treatment is performed on the surface of the semi-finished product obtained in step three, the laser spot temperature is 2880-3000℃, the laser scanning speed is 400-1200 mm / s, and the spot diameter is 0.04-0.08 mm; after the high-energy laser melting treatment is completed, quenching + tempering treatment is performed to obtain a corrosion-resistant metal material, and the corrosion-resistant metal material is coated in a roll coating manner 20μm thick nano-passivation coating, and baking at 150 250℃ until dry, to obtain the finished anti-corrosion, nano-black passivation type metal material;

[0039] The nano-passivation coating is made of nano-passivation paint, and the nano-passivation paint comprises water-based polyester resin, silane coupling agent, carbon black, and black titanium dioxide nanoparticles.

[0040] In the preparation process of the application, high-energy laser is used to melt the surface of the steel material, which improves the compatibility of the surface modified tungsten carbide and the stainless steel matrix, and is beneficial to improving the overall corrosion resistance of the steel material.

[0041] The preparation process of the application is relatively simple, and the operation difficulty is low, which is convenient for industrial production and manufacturing.

[0042] The anti-corrosion, nano-black passivation type metal material is applied to the internal metal parts of electronic products.

[0043] In summary, the application has the following advantages:

[0044] 1. The anti-corrosion, nano-black passivation type metal material in the application is applied to the internal metal parts of electronic products, which can meet the salt mist resistance of steel in the electronic industry and does not need subsequent electroplating treatment, the precision of electronic devices is relatively good, the product yield is improved, and the product cost is reduced.

[0045] 2. The preparation process of the application is relatively simple, and the operation difficulty is low, which is convenient for industrial production and manufacturing. DETAILED DESCRIPTION

[0046] In order to further understand the application, the preferred embodiments of the application are described below in combination with examples and comparative examples.

[0047] EXAMPLE

[0048] The anti-corrosion, nano-black passivation type metal material is made of stainless steel powder, surface modified tungsten carbide, and spherical graphene modified stainless steel powder through powder metallurgy process.

[0049] The total mass of the surface modified tungsten carbide and the spherical graphene modified stainless steel powder is equal to 0.5-1.0wt% of the mass of the anti-corrosion, nano-black passivation type metal material.

[0050] Preferably, the total mass of the surface-modified tungsten carbide and the spherical graphene-modified stainless steel powder is equal to 0.7-0.8wt% of the mass of the corrosion-resistant, nano-black passivated metal material.

[0051] The mass ratio of the surface-modified tungsten carbide to the spherical graphene-modified stainless steel powder is 1:(0.1-5).

[0052] Preferably, the mass ratio of the surface-modified tungsten carbide to the spherical graphene-modified stainless steel powder is 1:(0.5-2).

[0053] The surface-modified tungsten carbide comprises a base tungsten carbide and nano-modified metal particles loaded on the surface of the base tungsten carbide, and the nano-modified metal particles at least comprise nano-iron particles. The base tungsten carbide is nano-tungsten carbide with an average particle size of 50-500nm. The nano-modified metal particles are loaded on the surface of the base tungsten carbide by a sol-gel method, and the loading rate of the nano-modified metal particles is ≥5wt%.

[0054] The spherical graphene-modified stainless steel powder is made of stainless steel powder and surface-modified graphene by a spray method.

[0055] The addition amount of the surface-modified graphene is equal to 5-10wt% of the mass of the spherical graphene-modified stainless steel powder.

[0056] The particle size D50 of the spherical graphene-modified stainless steel powder is ≤35 microns.

[0057] The surface-modified graphene comprises a base graphene and nano-modified metal particles loaded on the surface of the base graphene, and the loading rate of the nano-modified metal particles is ≥5wt%. The nano-modified metal particles at least comprise nano-iron particles. Alternatively, the surface-modified graphene comprises a base graphene and metal monomers anchored to defect sites of the base graphene, and the loading rate of the metal monomers is ≥1wt%, and the metal monomers at least comprise iron monomers.

[0058] The preparation method of the spherical graphene-modified stainless steel powder is as follows:

[0059] S1. The stainless steel powder and the surface-modified graphene are uniformly mixed and then transferred to a planetary ball mill, tungsten carbide is used as the grinding bead, and dry ball milling is performed at 60-80rpm for 20-40min to obtain a mixed alloy powder;

[0060] S2. The mixed alloy powder obtained in S1 is made into a spherical alloy powder by an aerosol method, and the particle size D50 of the obtained spherical alloy powder is 5-35 microns, and the tap density is ≥1.75g / cm 50 . 3

[0061] A preparation process of a corrosion-resistant, nano-black passivated metal material comprises the following steps:

[0062] ​Step one, preparation of surface modified tungsten carbide, spherical graphene modified stainless steel powder;

[0063] Step two, the surface modified tungsten carbide, spherical graphene modified stainless steel powder prepared in step one is mixed with stainless steel powder according to the ratio, and then transferred to a planetary ball mill, with tungsten carbide as the grinding beads, dry ball milling at 60-80 rpm for 5-15 min to obtain a mixed alloy powder;

[0064] Step three, the mixed alloy powder obtained in step two is placed in a forming mold for hot isostatic pressing treatment, and the hot isostatic pressing parameters are as follows: forming temperature 880-950℃, forming pressure: first pressurized to 120-160MPa at 15-20MPa / s, pressure maintaining for 10-20s, then pressurized to 200-240MPa at 8-10MPa / s, pressure maintaining for 20-30s, then pressurized to 320-350MPa at 4-6MPa / s, pressure maintaining for 20-30s, then pressurized to 450-500MPa at 1-2MPa / s, pressure maintaining for 30-60s, then depressurized to 550-600MPa at 0.5-1MPa / s, pressure maintaining for 30-60s, then depressurized to 280-320MPa at 1-2MPa / s, pressure maintaining for 30-60s, then depressurized to 160-200MPa at 4-8MPa / s, pressure maintaining for 30-60s, finally depressurized to 0MPa at 15-20MPa / s, forming speed is 0.5-5mm / s, cooling to room temperature, grinding burrs to obtain a semi-finished product;

[0065] Step four, high-energy laser melting treatment is performed on the surface of the semi-finished product obtained in step three, the laser spot temperature is 2880-3000℃, the laser scanning speed is 400-1200mm / s, the spot diameter is 0.04-0.08mm, after high-energy laser melting treatment, quenching+tempering treatment is performed to obtain a corrosion-resistant metal material, the corrosion-resistant metal material is coated with a 8 20μm thick nano passivation coating by roll coating, and baked at 150 250℃ until dry to obtain a finished product of corrosion-resistant, nano black passivation type metal material.

[0066] The nano passivation coating is made of nano passivation coating, which is made of water-based polyester resin, silane coupling agent, carbon black, and black titanium dioxide nanoparticles.

[0067] The total mass of carbon black and black titanium dioxide nanoparticles accounts for 3-10wt% of the total mass of the nano passivation coating.

[0068] The mass ratio of carbon black and black titanium dioxide nanoparticles is 1:(0.2-0.4).

[0069] The mass of the silane coupling agent accounts for 0.5-1.0 wt% of the total mass of the nano passivation coating. Preferably, the silane coupling agent is KH570, and the mass of KH570 accounts for 0.6-0.75 wt% of the total mass of the nano passivation coating.

[0070] The solid content of the aqueous polyester resin is 30-55 wt%.

[0071] In the present application, the anticorrosion and nano black passivation type metal material is applied to the internal metal parts of electronic products, which can meet the requirements of salt spray resistance (GB / T 2423.17 salt spray test 78H-85H) for steel in the electronic industry without subsequent electroplating treatment. The electronic device has relatively good precision, which improves the product yield of the anticorrosion and nano black passivation type metal material, reduces the production cost of the product, and enhances the production competitive advantage.

[0072] Preparation Example 1: The surface modified tungsten carbide is prepared by a sol-gel method, and the preparation method is as follows:

[0073] S1. 4.04 g of iron nitrate nonahydrate (Fe(NO3)3·9H2O, molecular weight 404, iron content 13.82 wt%), 250 mL of distilled water, and a magnetic stirrer were added to a 500 mL beaker, the magnetic stirring speed was adjusted to 160 rpm, and stirring was performed for 30 min to obtain an aqueous iron nitrate solution with a concentration of 0.04 mol / L;

[0074] S2. Under the stirring speed of 160 rpm, 20 g of nano tungsten carbide (Brofos-WC-200 nano tungsten carbide purchased from Brofos Nanotech (Ningbo) Co., Ltd., average particle size 200 nm, purity 99.9%, hexagonal crystal type) was added to the 500 mL beaker, the addition speed of the nano tungsten carbide was 0.2 g / s, after the addition of the nano tungsten carbide was completed, the magnetic stirring was maintained at 160 rpm for 5 min, then the magnetic stirrer was removed, and an ultrasonic stirrer was used for ultrasonic stirring, the ultrasonic frequency was 44 kHz, the power was 600 W, the ultrasonic dispersion was performed for 30 min, then the water bath was heated to 45℃, and 3.2 wt% ammonia water was added, the dropping speed of the ammonia water was 2 drops / s, and the ammonia water was added dropwise to the Fe 3+ After complete precipitation, Fe(OH)3 was formed, the magnetic stirrer was placed in the Fe(OH)3, the magnetic stirring was performed at 80 rpm for 2 h, and the Fe(OH)3 / WC binary colloid was obtained after standing and aging for 24 h;

[0075] S3. After the Fe(OH)3 / WC binary colloid was washed with distilled water for three times, the Fe(OH)3 / WC solid material was obtained by reduced pressure filtration and vacuum drying, and was ready for use;

[0076] S4. The obtained Fe(OH)3 / WC solid material was transferred into an atmosphere tube furnace for calcination treatment, and was calcined at 800°C for 5.0 h under an air atmosphere at a rate of 10°C / min, to obtain Fe2O3@WC composite powder. Then, hydrogen-argon mixed gas was introduced into the atmosphere tube furnace, the volume ratio of hydrogen to argon in the hydrogen-argon mixed gas was 1:4, and the reduction reaction was carried out at 800°C for 6.0 h. After the reduction reaction was completed, the furnace was opened, and the nano Fe@WC solid powder was naturally cooled to room temperature;

[0077] S5. The obtained nano Fe@WC solid powder was placed in a planetary ball mill, and was subjected to low-speed ball milling treatment under a nitrogen atmosphere with tungsten carbide as a grinding bead, at a speed of 60 rpm for 30 min, to obtain tungsten carbide modified by surface nano Fe, and the loading rate of nano Fe was 2.99 wt%.

[0078] Preparation Example 2 was different from Preparation Example 1 in that S1. 6.9 g of iron nitrate nonahydrate, 250 mL of distilled water, and a magnetic stirring bar were added into a 500 mL beaker, and stirring was performed at a magnetic stirring speed of 160 rpm for 30 min, to obtain an iron nitrate aqueous solution with a concentration of 0.0684 mol / L. The loading rate of nano Fe in the obtained tungsten carbide modified by surface nano Fe was 5.01 wt%.

[0079] Preparation Example 3 was different from Preparation Example 1 in that S1. 14.3 g of iron nitrate nonahydrate, 250 mL of distilled water, and a magnetic stirring bar were added into a 500 mL beaker, and stirring was performed at a magnetic stirring speed of 160 rpm for 30 min, to obtain an iron nitrate aqueous solution with a concentration of 0.142 mol / L. The loading rate of nano Fe in the obtained tungsten carbide modified by surface nano Fe was 9.90 wt%.

[0080] Preparation Example 4 was different from Preparation Example 1 in that S1. 30.3 g of iron nitrate nonahydrate, 250 mL of distilled water, and a magnetic stirring bar were added into a 500 mL beaker, and stirring was performed at a magnetic stirring speed of 160 rpm for 30 min, to obtain an iron nitrate aqueous solution with a concentration of 0.3 mol / L. The loading rate of nano Fe in the obtained tungsten carbide modified by surface nano Fe was 19.04 wt%.

[0081] Preparation Example 5: The surface modified graphene was prepared by a sol-gel method, and the preparation method was as follows:

[0082] S1. 0.404 g of iron nitrate nonahydrate, 250 mL of distilled water, and a magnetic stirring bar were added into a 500 mL beaker, and stirring was performed at a magnetic stirring speed of 160 rpm for 30 min, to obtain an iron nitrate aqueous solution with a concentration of 0.004 mol / L;

[0083] S2. In a 500 mL beaker, 2 g of amino-functionalized graphene (amino-functionalized graphene BKMK2009, purity 98%, thickness 0.55-3.74 nm, size 0.5-3 μm, layer number 10, ordered from Suzhou Kefan New Material Technology Co., Ltd.) was added at a stirring speed of 320 rpm. The addition rate of the amino-functionalized graphene was 0.1 g / s. After the addition of the tungsten carbide nanoparticles was completed, the magnetic stirring was maintained at 320 rpm for 5 min. Then, the magnetic stirrer was removed, and an ultrasonic stirrer was used for ultrasonic stirring at a frequency of 44 kHz and a power of 600 W for 30 min. After the water bath was heated to 50°C, 3.2 wt% ammonia water was added dropwise at a rate of 1 drop / s. The ammonia water was added dropwise to the Fe 3+ After complete precipitation, Fe(OH)3was formed. The Fe(OH)3was placed in a magnetic stirrer and stirred at 200 rpm for 2 h. After standing for 24 h, Fe(OH)3 / AGS binary colloids were obtained.

[0084] S3. After the Fe(OH)3 / AGS binary colloids were washed with distilled water for three times, the Fe(OH)3 / AGS solid material was obtained by reduced pressure filtration and vacuum drying, which was ready for use.

[0085] S4. The obtained Fe(OH)3 / AGS solid material was placed in a gas atmosphere tube furnace for calcination treatment. The temperature was increased to 760°C at a rate of 10°C / min under air atmosphere, and calcination was performed for 4 h. Then, hydrogen and argon mixed gas was introduced into the tube furnace, and the volume ratio of hydrogen to argon in the mixed gas was 1:3. Reduction reaction was performed at 760°C for 4.0 h. After the reduction reaction was completed, the furnace was opened, and the temperature was naturally cooled to room temperature to obtain nano-Fe@AGS solid powder.

[0086] S5. The obtained nano-Fe@AGS solid powder was placed in a planetary ball mill, and nitrogen was introduced for protection. Tungsten carbide was used as a grinding bead for low-speed ball milling treatment under nitrogen atmosphere. The ball milling was performed at 60 rpm for 60 min to obtain graphene modified by surface nano-Fe. The loading rate of nano-Fe was 2.98 wt%.

[0087] Preparation Example 6 was different from Preparation Example 5 in that S1. 6.95 g of iron nitrate nonahydrate, 250 mL of distilled water, and a magnetic stirrer were added to a 500 mL beaker. The magnetic stirring speed was adjusted to 160 rpm, and stirring was performed for 30 min to obtain an aqueous solution of iron nitrate with a concentration of 0.0684 mol / L. The loading rate of nano-Fe in the obtained graphene modified by surface nano-Fe was 5.03 wt%.

[0088] Preparation Example 7 is different from Preparation Example 5 in that: S1. 14.3 g of iron nitrate nonahydrate, 250 mL of distilled water, and a magnetic stirring bar were added to a 500 mL beaker, the magnetic stirring speed was adjusted to 160 rpm, and stirring was performed for 30 min to obtain an aqueous iron nitrate solution with a concentration of 0.142 mol / L. The nano-Fe loading rate in the obtained surface nano-Fe modified graphene was 9.85 wt%.

[0089] Preparation Example 8 is different from Preparation Example 5 in that: S1. 30.3 g of iron nitrate nonahydrate, 250 mL of distilled water, and a magnetic stirring bar were added to a 500 mL beaker, the magnetic stirring speed was adjusted to 160 rpm, and stirring was performed for 30 min to obtain an aqueous iron nitrate solution with a concentration of 0.3 mol / L. The nano-Fe loading rate in the obtained surface nano-Fe modified graphene was 19.01 wt%.

[0090] Preparation Example 9: The surface modified graphene is metal single-atom Fe modified graphene (produced by Beijing Graphene Technology Research Institute Co., Ltd.), and the preparation method is as follows:

[0091] S1. 2 g of graphene (graphene TNRGO of Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, specific surface area: 500-1000 m2 / g, thickness: 0.55-3.74 nm, diameter: 0.5-3 μm, layer number: <10 layers) was dispersed in 500 g of distilled water to obtain a graphene dispersion liquid;

[0092] Meanwhile, 2 g of KOH was dissolved in 250 mL of distilled water to obtain a 8 g / L KOH aqueous solution;

[0093] S2. The graphene dispersion liquid in S1 and the 8 g / L KOH aqueous solution in S1 were added to a 1.5 L beaker and stirred at a magnetic stirring speed of 200 rpm for 15 min. After uniform mixing, the water bath was warmed to 80℃, and stirring was performed at a speed of 200 rpm for 10 min at 80℃. The magnetic stirring bar was removed, and ultrasonic stirring was performed using an ultrasonic stirring machine at an ultrasonic frequency of 44 kHz and a power of 600 W for 30 min. The product was obtained by vacuum drying.

[0094] S3. The obtained surface alkali-treated graphene was placed in crucible A, 0.12 g of iron chloride was placed in crucible B, crucible A was loaded in the downstream zone of the tube furnace, and crucible B was loaded in the upstream zone of the tube furnace. The tube furnace was sealed, and the upstream temperature zone of the tube furnace was raised to 800℃ at a rate of 10℃ / min from room temperature and was kept at 800℃ for 60 min. Meanwhile, the downstream temperature zone of the tube furnace was raised to 800℃ at a rate of 10℃ / min from room temperature and was kept at 800℃ for 60 min. A metal single-atom doped graphene precursor was obtained.

[0095] S4. The metal monatomic atom-doped graphene precursor was added into dilute hydrochloric acid with a concentration of 1.0 mol / L, stirred, vacuum filtered, washed with distilled water, and dried to obtain metal monatomic atom Fe-modified graphene, wherein the loading rate of metal monatomic atom Fe in the metal monatomic atom Fe-modified graphene was 0.49 wt%.

[0096] Preparation Example 10 is different from Preparation Example 9 in that: S3. The obtained surface alkali-treated graphene was placed in crucible A, 0.28 g of iron chloride was placed in crucible B, crucible A was loaded in the downstream zone of the tube furnace, crucible B was loaded in the upstream zone of the tube furnace, the tube furnace was sealed, and under an argon atmosphere, the upstream temperature zone of the tube furnace was raised to 800 ℃ at a temperature rising rate of 10 ℃ / min for 60 min, while the downstream temperature zone of the tube furnace was raised to 800 ℃ at a temperature rising rate of 10 ℃ / min for 60 min to obtain a metal monatomic atom-doped graphene precursor. The loading rate of metal monatomic atom Fe in the obtained metal monatomic atom Fe-modified graphene was 1.01 wt%.

[0097] Preparation Example 11 is different from Preparation Example 9 in that: S3. The obtained surface alkali-treated graphene was placed in crucible A, 0.58 g of iron chloride was placed in crucible B, crucible A was loaded in the downstream zone of the tube furnace, crucible B was loaded in the upstream zone of the tube furnace, the tube furnace was sealed, and under an argon atmosphere, the upstream temperature zone of the tube furnace was raised to 800 ℃ at a temperature rising rate of 10 ℃ / min for 60 min, while the downstream temperature zone of the tube furnace was raised to 800 ℃ at a temperature rising rate of 10 ℃ / min for 60 min to obtain a metal monatomic atom-doped graphene precursor. The loading rate of metal monatomic atom Fe in the obtained metal monatomic atom Fe-modified graphene was 1.98 wt%.

[0098] Preparation Example 12 is different from Preparation Example 9 in that: S3. The obtained surface alkali-treated graphene was placed in crucible A, 1.6 g of iron chloride was placed in crucible B, crucible A was loaded in the downstream zone of the tube furnace, crucible B was loaded in the upstream zone of the tube furnace, the tube furnace was sealed, and under an argon atmosphere, the upstream temperature zone of the tube furnace was raised to 800 ℃ at a temperature rising rate of 10 ℃ / min for 60 min, while the downstream temperature zone of the tube furnace was raised to 800 ℃ at a temperature rising rate of 10 ℃ / min for 60 min to obtain a metal monatomic atom-doped graphene precursor. The loading rate of metal monatomic atom Fe in the obtained metal monatomic atom Fe-modified graphene was 5.08 wt%.

[0099] Example 1: An anti-corrosion, nano-black passivation type metal material is made of stainless steel powder, surface-modified tungsten carbide in Preparation Example 2, and spherical graphene-modified stainless steel powder in Preparation Example 6 by a powder metallurgy process. The total mass of the surface-modified tungsten carbide and the spherical graphene-modified stainless steel powder is equal to 0.5wt% of the mass of the anti-corrosion, nano-black passivation type metal material. The mass ratio of the surface-modified tungsten carbide to the spherical graphene-modified stainless steel powder is 4:1.

[0100] A preparation process of an anti-corrosion, nano-black passivation type metal material, comprising the following steps:

[0101] Step one, the preparation method of the surface-modified tungsten carbide is described in Preparation Example 2.

[0102] The preparation method of the spherical graphene-modified stainless steel powder is described in Preparation Example 6.

[0103] Step two, mix the surface-modified tungsten carbide in Preparation Example 2 and the spherical graphene-modified stainless steel powder in Preparation Example 6 with stainless steel powder (304 stainless steel powder from Hebei Ruichuang Metal Material Co., Ltd., purity 99.9%, 500 mesh) according to the proportion, and then transfer them to a planetary ball mill. Use tungsten carbide as the grinding beads and dry ball mill at 80rpm for 15min to obtain a mixed alloy powder.

[0104] Step three, place the mixed alloy powder obtained in Step two in a forming mold for hot isostatic pressing treatment. The hot isostatic pressing parameters are as follows: forming temperature 920℃, forming pressure: first pressurize at 15MPa / s to 150MPa, hold for 20s, then pressurize at 10MPa / s to 240MPa, hold for 30s, then pressurize at 5MPa / s to 350MPa, hold for 30s, then pressurize at 2MPa / s to 500MPa, hold for 60s, then pressurize at 0.5MPa / s to 600MPa, hold for 30s, then depressurize at 2MPa / s to 300MPa, hold for 60s, then depressurize at 4MPa / s to 200MPa, hold for 30s, and finally depressurize at 20MPa / s to 0MPa. The forming speed is 1.0mm / s, cool to room temperature, and polish the burrs to obtain a semi-finished product.

[0105] Step four, high-energy laser melting treatment is performed on the surface of the semi-finished product obtained in step three, the laser spot temperature is 2950±5℃, the laser power is 420W, the laser scanning speed is 800mm / s, the spot diameter is 0.08mm, after the high-energy laser melting treatment is completed, cooling to room temperature, quenching treatment, heating to 460℃ at a rate of 5℃ / min, keeping for 15min, adjusting the temperature to 1020℃ at a rate of 10℃ / min, keeping for 90min, and then using gas quenching: inputting nitrogen-oxygen mixed gas at a temperature of 65℃, the oxygen volume content in the nitrogen-oxygen mixed gas is 15%, rapidly cooling to 400℃, and then performing tempering treatment: adjusting the temperature to 650℃ at a rate of 5℃ / min, keeping for 1.5h, cooling to 220℃ at a rate of 10℃ / min, opening the furnace and naturally cooling, secondary tempering treatment: adjusting the temperature to 680℃ at a rate of 6℃ / min, keeping for 1.5h, cooling to 200℃ at a rate of 15℃ / min, opening the furnace and naturally cooling to room temperature, obtaining the corrosion-resistant metal material, the corrosion-resistant metal material is coated with a 20μm-thick nano-passivation coating in a roll-coating manner, and is baked to dry at 175℃, obtaining the finished product of the corrosion-resistant nano-black passivation metal material.

[0106] The nano-passivation coating is made of a nano-passivation coating material, and the nano-passivation coating material is made of 954g of water-based polyester resin (solid content of 32wt%, Refober ® HYR-2402 water-based polyurethane resin, viscosity of 600mPa*s at 23℃, pH value of 7.7), 6g of silane coupling agent KH570, 30g of carbon black (carbon black TS720, Cabot), and 10g of black titanium dioxide nanoparticles (sharp titanium type 5nm titanium dioxide, Yame Nano).

[0107] Example 2 differs from Example 1 in that the corrosion-resistant nano-black passivation metal material is made of stainless steel powder, surface-modified tungsten carbide in Preparation Example 3, and spherical graphene-modified stainless steel powder in Preparation Example 6 through a powder metallurgy process.

[0108] Example 3 differs from Example 1 in that the corrosion-resistant nano-black passivation metal material is made of stainless steel powder, surface-modified tungsten carbide in Preparation Example 4, and spherical graphene-modified stainless steel powder in Preparation Example 6 through a powder metallurgy process.

[0109] Example 4 differs from Example 1 in that the corrosion-resistant nano-black passivation metal material is made of stainless steel powder, surface-modified tungsten carbide in Preparation Example 2, and spherical graphene-modified stainless steel powder in Preparation Example 7 through a powder metallurgy process.

[0110] Example 5 differs from Example 1 in that the corrosion-resistant nano-black passivation metal material is made of stainless steel powder, surface-modified tungsten carbide in Preparation Example 2, and spherical graphene-modified stainless steel powder in Preparation Example 8 through a powder metallurgy process.

[0111] Example 6 differs from Example 1 in that the corrosion resistant, nano black passivated metal material is made by powder metallurgy process from stainless steel powder, surface modified tungsten carbide in Preparation Example 2, and spherical graphene modified stainless steel powder in Preparation Example 10.

[0112] Example 7 differs from Example 1 in that the corrosion resistant, nano black passivated metal material is made by powder metallurgy process from stainless steel powder, surface modified tungsten carbide in Preparation Example 2, and spherical graphene modified stainless steel powder in Preparation Example 11.

[0113] Example 8 differs from Example 1 in that the corrosion resistant, nano black passivated metal material is made by powder metallurgy process from stainless steel powder, surface modified tungsten carbide in Preparation Example 2, and spherical graphene modified stainless steel powder in Preparation Example 12.

[0114] Example 9 differs from Example 1 in that the total mass of surface modified tungsten carbide and spherical graphene modified stainless steel powder is equal to 0.75 wt% of the mass of the corrosion resistant, nano black passivated metal material.

[0115] Example 10 differs from Example 1 in that the total mass of surface modified tungsten carbide and spherical graphene modified stainless steel powder is equal to 1.0 wt% of the mass of the corrosion resistant, nano black passivated metal material.

[0116] Example 11 differs from Example 1 in that the mass ratio of surface modified tungsten carbide to spherical graphene modified stainless steel powder is 2:1.

[0117] Example 12 differs from Example 1 in that the mass ratio of surface modified tungsten carbide to spherical graphene modified stainless steel powder is 3:2.

[0118] Example 13 differs from Example 1 in that the mass ratio of surface modified tungsten carbide to spherical graphene modified stainless steel powder is 1:1.

[0119] Example 14 differs from Example 1 in that the mass ratio of surface modified tungsten carbide to spherical graphene modified stainless steel powder is 1:2.

[0120] Example 15 differs from Example 1 in that the mass ratio of surface modified tungsten carbide to spherical graphene modified stainless steel powder is 1:5.

[0121] Example 16 differs from Example 1 in that the anti-corrosion, nano-black passivation type metal material is made from stainless steel powder, surface-modified tungsten carbide in Preparation Example 3, and spherical graphene-modified stainless steel powder in Preparation Example 11 by a powder metallurgy process. The total mass of the surface-modified tungsten carbide and the spherical graphene-modified stainless steel powder is equal to 0.75 wt% of the mass of the anti-corrosion, nano-black passivation type metal material. The mass ratio of the surface-modified tungsten carbide to the spherical graphene-modified stainless steel powder is 3:2.

[0122] Example 17 differs from Example 1 in that in Step 3, the mixed alloy powder obtained in Step 2 is placed in a forming mold for hot isostatic pressing treatment, and the hot isostatic pressing parameters are as follows: forming temperature 880-950°C, forming pressure: first pressurized at 20 MPa / s to 150 MPa, pressure maintained for 15 s, then pressurized at 10 MPa / s to 200 MPa, pressure maintained for 25 s, then pressurized at 5 MPa / s to 350 MPa, pressure maintained for 30 s, then pressurized at 1 MPa / s to 500 MPa, pressure maintained for 30 s, then pressurized at 0.5 MPa / s to 600 MPa, pressure maintained for 60 s, then depressurized at 1 MPa / s to 300 MPa, pressure maintained for 60 s, then depressurized at 5 MPa / s to 200 MPa, pressure maintained for 30 s, and finally depressurized at 20 MPa / s to 0 MPa, forming speed is 1 mm / s, cooled to room temperature, and the burrs are ground to obtain a semi-finished product.

[0123] Example 18 differs from Example 16 in that in Step 3, the mixed alloy powder obtained in Step 2 is placed in a forming mold for hot isostatic pressing treatment, and the hot isostatic pressing parameters are as follows: forming temperature 880-950°C, forming pressure: first pressurized at 20 MPa / s to 150 MPa, pressure maintained for 15 s, then pressurized at 10 MPa / s to 200 MPa, pressure maintained for 25 s, then pressurized at 5 MPa / s to 350 MPa, pressure maintained for 30 s, then pressurized at 1 MPa / s to 500 MPa, pressure maintained for 30 s, then pressurized at 0.5 MPa / s to 600 MPa, pressure maintained for 60 s, then depressurized at 1 MPa / s to 300 MPa, pressure maintained for 60 s, then depressurized at 5 MPa / s to 200 MPa, pressure maintained for 30 s, and finally depressurized at 20 MPa / s to 0 MPa, forming speed is 1 mm / s, cooled to room temperature, and the burrs are ground to obtain a semi-finished product.

[0124] Comparative Example 1 differs from Example 1 in that the anti-corrosion, nano-black passivation type metal material is made from stainless steel powder, nano-tungsten carbide, and graphene by a powder metallurgy process.

[0125] The content of nano-tungsten carbide in the anti-corrosion, nano-black passivation type metal material prepared in Comparative Example 1 is equal to the mass of the surface-modified tungsten carbide in the anti-corrosion, nano-black passivation type metal material prepared in Example 1.

[0126] The content of graphene in the anti-corrosion, nano-black passivated metal material prepared in Comparative Example 1 is equal to the mass of the surface-modified graphene in the anti-corrosion, nano-black passivated metal material prepared in Example 1.

[0127] Comparative Example 2 differs from Example 1 in that the anti-corrosion, nano-black passivated metal material is prepared by powder metallurgy from stainless steel powder, surface-modified tungsten carbide in Preparation Example 2, and graphene.

[0128] The content of graphene in the anti-corrosion, nano-black passivated metal material prepared in Comparative Example 2 is equal to the mass of the surface-modified graphene in the anti-corrosion, nano-black passivated metal material prepared in Example 1.

[0129] Comparative Example 3 differs from Example 1 in that the anti-corrosion, nano-black passivated metal material is prepared by powder metallurgy from stainless steel powder, nano-tungsten carbide, and surface-modified graphene in Preparation Example 6.

[0130] The content of nano-tungsten carbide in the anti-corrosion, nano-black passivated metal material prepared in Comparative Example 3 is equal to the mass of the surface-modified tungsten carbide in the anti-corrosion, nano-black passivated metal material prepared in Example 1.

[0131] Comparative Example 4 differs from Example 1 in that the anti-corrosion, nano-black passivated metal material is prepared by powder metallurgy from stainless steel powder, surface-modified tungsten carbide in Preparation Example 1, and spherical graphene-modified stainless steel powder in Preparation Example 6.

[0132] Comparative Example 5 differs from Example 1 in that the anti-corrosion, nano-black passivated metal material is prepared by powder metallurgy from stainless steel powder, surface-modified tungsten carbide in Preparation Example 1, and spherical graphene-modified stainless steel powder in Preparation Example 5.

[0133] Comparative Example 6 differs from Example 1 in that the anti-corrosion, nano-black passivated metal material is prepared by powder metallurgy from stainless steel powder, surface-modified tungsten carbide in Preparation Example 2, and spherical graphene-modified stainless steel powder in Preparation Example 5.

[0134] Comparative Example 7 differs from Example 1 in that the anti-corrosion, nano-black passivated metal material is prepared by powder metallurgy from stainless steel powder, surface-modified tungsten carbide in Preparation Example 2, and spherical graphene-modified stainless steel powder in Preparation Example 9.

[0135] Comparative Example 8 differs from Example 1 in that the anti-corrosion, nano-black passivation type metal material is made from stainless steel powder and the surface-modified tungsten carbide in Preparation Example 2 by a powder metallurgy process. The amount of the surface-modified tungsten carbide in Preparation Example 2 added is 0.5wt%.

[0136] Comparative Example 9 differs from Example 1 in that the anti-corrosion, nano-black passivation type metal material is made from stainless steel powder and the spherical graphene-modified stainless steel powder in Preparation Example 6 by a powder metallurgy process. The amount of the spherical graphene-modified stainless steel powder in Preparation Example 6 added is 0.5wt%.

[0137] Comparative Example 10 differs from Example 1 in that the total mass of the surface-modified tungsten carbide and the spherical graphene-modified stainless steel powder is equal to 0.2wt% of the mass of the anti-corrosion, nano-black passivation type metal material.

[0138] Comparative Example 11 differs from Example 1 in that the total mass of the surface-modified tungsten carbide and the spherical graphene-modified stainless steel powder is equal to 1.5wt% of the mass of the anti-corrosion, nano-black passivation type metal material.

[0139] Comparative Example 12 differs from Example 1 in that in Step 3, the mixed alloy powder obtained in Step 2 is placed in a forming mold for hot isostatic pressing treatment, and the hot isostatic pressing parameters are as follows: forming temperature 920℃, forming pressure: first pressurized to 600MPa at 15MPa / s, pressure holding for 170s, then depressurized to 0MPa at 20MPa / s, forming speed is 1.0mm / s, cooled to room temperature, and the burrs are polished to obtain a semi-finished product.

[0140] Comparative Example 13 differs from Example 1 in that in Step 4, the semi-finished product obtained in Step 3 is subjected to quenching treatment, heated to 460℃ at 5℃ / min, held for 15min, adjusted to 1020℃ at 10℃ / min, held for 90min, then gas quenching: input temperature is 65℃ of nitrogen-oxygen mixed gas, oxygen content in the nitrogen-oxygen mixed gas is 15%, rapidly cooled to 400℃, then tempering treatment: adjusted to 650℃ at 5℃ / min, held for 1.5h, then cooled to 220℃ at 10℃ / min, furnace is opened and naturally cooled, secondary tempering treatment: adjusted to 680℃ at 6℃ / min, held for 1.5h, then cooled to 200℃ at 15℃ / min, furnace is opened and naturally cooled to room temperature, to obtain an anti-corrosion type metal material, the anti-corrosion type metal material is coated with a 20μm thick nano-passivation coating by roller coating, and baked to dry at 175℃, to obtain a finished anti-corrosion, nano-black passivation type metal material.

[0141] Performance test: 1. Salt spray resistance test method: according to GB / T 2423.17. 2. Hardness test method: according to GB / T 230.1-2004 "Metal Rockwell hardness test Part 1: test method". 3. Yield strength test: according to GB / T 228.1. 4. Toughness test is V-impact test: according to GB / T 229-2007.

[0142] Table 1: Test parameters of the anti-corrosion, nano black passivated metal material prepared in examples 1-18 and comparative examples 1-13

[0143]

[0144] It can be seen from the combination of examples 1 and comparative examples 1-3 and table 1 that the anti-corrosion, nano black passivated metal material made of stainless steel powder, surface modified tungsten carbide, and spherical graphene modified stainless steel powder through powder metallurgy process has good corrosion resistance, wear resistance and mechanical strength. Without surface modification treatment of tungsten carbide and graphene, its dispersion performance in the stainless steel matrix is poor, resulting in poor mechanical strength of the prepared steel material, which cannot meet the actual use requirements of internal metal parts of electronic products.

[0145] It can be seen from the combination of examples 1-8 and comparative examples 4-9 and table 1 that the loading rate of nano modified iron metal particles in the surface modified tungsten carbide is ≥5wt%, otherwise the dispersion performance of the prepared surface modified tungsten carbide in the stainless steel matrix is also relatively poor, resulting in low mechanical strength of the prepared steel material, limiting its application range.

[0146] It can be seen from the combination of examples 1-8 and comparative examples 4-9 and table 1 that the loading rate of nano modified iron metal particles in the surface modified graphene is ≥5wt%, otherwise the dispersion performance of the prepared surface modified graphene in the stainless steel matrix is also relatively poor, resulting in low mechanical strength of the prepared steel material, limiting its application range.

[0147] It can be seen from the combination of examples 1-8 and comparative examples 4-9 and table 1 that the loading rate of metal iron single atom in the surface single atom iron modified graphene is ≥1wt%, otherwise the dispersion performance of the prepared surface modified graphene in the stainless steel matrix is also relatively poor, resulting in low mechanical strength of the prepared steel material, limiting its application range.

[0148] It can be seen from the combination of the embodiment 1, the embodiments 9-10 and the comparative examples 10-11 and the combination of the table 1 that the total mass of the surface modified tungsten carbide and the spherical graphene modified stainless steel powder is equal to 0.75wt% of the mass of the corrosion resistant, nano black passivated metal material, the prepared steel material has relatively optimal comprehensive performance, and has relatively good economic performance.

[0149] It can be seen from the combination of the embodiment 1, the embodiments 11-15 and the comparative examples 8-9 and the combination of the table 1 that the surface modified tungsten carbide and the spherical graphene modified stainless steel powder are used in combination, the prepared steel material has relatively optimal comprehensive performance, and has relatively good economic performance, the mass ratio of the surface modified tungsten carbide and the spherical graphene modified stainless steel powder is preferably 3:2, the prepared steel material has relatively good corrosion resistance, wear resistance and mechanical strength, and is more economical in production, and is suitable for industrialized batch production.

[0150] It can be seen from the combination of the embodiment 1, the embodiment 17 and the comparative example 12 and the combination of the table 1 that the corrosion resistant, nano black passivated metal material prepared by the preparation method provided in the application has good corrosion resistance, wear resistance and mechanical strength, and the hot isostatic pressing process directly affects the comprehensive performance of the prepared corrosion resistant, nano black passivated metal material.

[0151] It can be seen from the combination of the embodiment 1 and the comparative example 13 and the combination of the table 1 that the corrosion resistant, nano black passivated metal material prepared by the preparation method provided in the application has good corrosion resistance, wear resistance and mechanical strength, and the high-energy laser melting treatment especially improves the corrosion resistance and wear resistance of the steel material.

[0152] In summary, the corrosion resistant, nano black passivated metal material in the application meets the salt mist resistance of the steel material in the electronic industry and does not need subsequent electroplating treatment, the electronic device has relatively good precision, improves the product yield, and reduces the product cost.

[0153] The specific embodiments are only an explanation of the application, and are not a limitation of the application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as the modifications are within the scope of the claims of the application, the modifications are protected by the patent law.

Claims

1. An anticorrosive, nanometer black passivated metal material, characterized by: The anticorrosion, nano black passivation type metal material is made of stainless steel powder, surface modified tungsten carbide and spherical graphene modified stainless steel powder by powder metallurgy process; the total mass of the surface modified tungsten carbide and the spherical graphene modified stainless steel powder is equal to 0.5-1.0wt% of the mass of the anticorrosion, nano black passivation type metal material; the mass ratio of the surface modified tungsten carbide to the spherical graphene modified stainless steel powder is 1:(0.1-5); the surface modified tungsten carbide comprises base tungsten carbide and nano modified metal particles loaded on the surface of the base tungsten carbide, and the nano modified metal particles at least comprise nano iron particles; The base tungsten carbide is nano tungsten carbide with an average particle size of 50-500nm; the nano modified metal particles are loaded on the surface of the base tungsten carbide by sol-gel method, and the loading rate of the nano modified metal particles is greater than or equal to 5wt%; The spherical graphene modified stainless steel powder is made of stainless steel powder and surface modified graphene by spray method; the adding amount of the surface modified graphene is equal to 5-10wt% of the mass of the spherical graphene modified stainless steel powder; the particle size D 50 ≤ 35 microns; The surface modified graphene comprises base graphene and nano modified metal particles loaded on the surface of the base graphene, and the loading rate of the nano modified metal particles is greater than or equal to 5wt%; the nano modified metal particles at least comprise nano iron particles; The surface modified graphene comprises base graphene and metal monatomic particles anchored to defect points of the base graphene, and the loading rate of the metal monatomic particles is greater than or equal to 1wt%; the metal monatomic particles at least comprise iron monatomic particles; The preparation method of the spherical graphene modified stainless steel powder is as follows: S1. After the stainless steel powder and the surface modified graphene are uniformly mixed, they are transferred into a planetary ball mill, tungsten carbide is used as grinding beads, and dry ball milling is performed at 60-80rpm for 20-40min to obtain mixed alloy powder; S2. The mixed alloy powder obtained in S1 is made into spherical alloy powder by the gas atomization method, the particle size D 50 of the spherical alloy powder obtained is 5-35 microns, and the tap density is ≥ 1.75 g / cm 3 ; The metal material is coated with a nano passivation coating, and the nano passivation coating is made of nano passivation paint, the nano passivation paint is made of water-based polyester resin, silane coupling agent, carbon black and black titanium dioxide nanoparticles, the total mass of the carbon black and the black titanium dioxide nanoparticles accounts for 3-10wt% of the total mass of the nano passivation paint; the mass of the silane coupling agent accounts for 0.5-1.0wt% of the total mass of the nano passivation paint; and the solid content of the water-based polyester resin is 30-55wt%.

2. The anticorrosive, nanometer black passivated metal material according to claim 1, characterized in that: The total mass of the surface modified tungsten carbide and the spherical graphene modified stainless steel powder is equal to 0.7-0.8wt% of the mass of the anticorrosion, nano black passivation type metal material; and the mass ratio of the surface modified tungsten carbide to the spherical graphene modified stainless steel powder is 1:(0.5-2).

3. A process for the preparation of a corrosion-protected, nanocrystalline black passivated metallic material according to any one of claims 1 to 2, characterized in that: The method comprises the following steps: Step one, preparation of surface modified tungsten carbide and spherical graphene modified stainless steel powder; Step two, the surface modified tungsten carbide and the spherical graphene modified stainless steel powder prepared in step one are uniformly mixed with stainless steel powder according to a proportion, and then transferred into a planetary ball mill, tungsten carbide is used as grinding beads, and dry ball milling is performed at 60-80rpm for 5-15min to obtain mixed alloy powder; Step three, the mixed alloy powder obtained in step two is placed in a forming mold for hot isostatic pressing treatment, and the hot isostatic pressing parameters are as follows: forming temperature 880-950℃, forming pressure: first pressurized to 120-160MPa at 15-20MPa / s, pressure maintaining for 10-20s, then pressurized to 200-240MPa at 8-10MPa / s, pressure maintaining for 20-30s, then pressurized to 320-350MPa at 4-6MPa / s, pressure maintaining for 20-30s, then pressurized to 450-500MPa at 1-2MPa / s, pressure maintaining for 30-60s, then pressurized to 550-600MPa at 0.5-1MPa / s, pressure maintaining for 30-60s, then depressurized to 280-320MPa at 1-2MPa / s, pressure maintaining for 30-60s, then depressurized to 160-200MPa at 4-8MPa / s, pressure maintaining for 30-60s, finally depressurized to 0MPa at 15-20MPa / s, forming speed is 0.5-5mm / s, cooling to room temperature, grinding burrs to obtain semi-finished product; Step four, high-energy laser melting treatment is performed on the surface of the semi-finished product obtained in step three, the laser spot temperature is 2880-3000℃, the laser scanning speed is 400-1200mm / s, the spot diameter is 0.04-0.08mm, after high-energy laser melting treatment, quenching+tempering treatment is performed to obtain the corrosion-resistant metal material, the corrosion-resistant metal material is coated with a 8-20μm thick nano passivation coating by roll coating, and is baked to dry at 150-250℃ to obtain the finished product of corrosion-resistant, nano black passivated metal material.

4. The corrosion-resistant, nano black passivated metal material of any one of claims 1-2 is applied to the internal metal components of electronic products.

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