High alloy steel workpiece surface laser bluing process

Abstract

The invention discloses a high alloy steel workpiece surface laser bluing process, which belongs to the field of metal surface treatment, and comprises the following steps: preparing a catalyst comprising ethanol, hydrogen peroxide, hydrochloric acid, sodium carboxymethyl cellulose, gas-phase nano silicon dioxide and deionized water; the catalyst comprises the following components in percentage by volume: 60-70% of ethanol, 10-12% of hydrogen peroxide, 8-10% of sodium carboxymethyl cellulose solution, 2% of gas-phase nano silicon dioxide dispersion liquid, 8-16% of deionized water and 0.25% of hydrochloric acid. The prepared catalyst is sprayed on the surface of a high alloy steel workpiece, and a layer of light yellow oxidation film is formed; laser is adopted to irradiate the surface of the high-alloy steel workpiece sprayed with the catalyst, bluing treatment is carried out, and a uniform Fe3O4 corrosion-resistant layer with the thickness of about 2-20 microns is formed on the surface of the high-alloy steel workpiece after bluing treatment is completed. According to the invention, the high-alloy steel workpiece has very strong corrosion resistance in air, a humid environment or an industrial environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal surface treatment, in particular to a laser bluing process for high-alloy steel workpiece surface. BACKGROUND

[0002] The bluing process is a surface treatment technology for preventing steel workpiece from corrosion and rusting. The principle is that a uniform and dense blue-black oxide film with certain thickness, strong adhesion and good corrosion resistance is formed on the surface of steel and other metals through chemical reaction, mainly oxidation reaction, which effectively isolates air and thus protects the inside of the steel workpiece from oxidation.

[0003] The laser strengthening can be used for bluing treatment on the surface of general metals. However, the high-alloy steel has high alloy content, and the elements of chromium, nickel, molybdenum and vanadium make the high-alloy steel have strong oxidation resistance and the surface is bright and difficult to absorb light. The conventional laser bluing treatment process has poor bluing effect, uneven surface and thin thickness after bluing treatment on the surface of high-alloy steel workpiece, and it is difficult to achieve the purpose of preventing the workpiece from corrosion and rusting. SUMMARY

[0004] The present application solves the technical problem of providing a laser bluing process for high-alloy steel workpiece surface. A thin and uniform Fe3O4 corrosion-resistant layer with a thickness of about 2-20 μm is formed on the surface of high-alloy steel workpiece by coating a special catalyst on the surface of high-alloy steel workpiece and using laser bluing process, so that the high-alloy steel has strong corrosion resistance in air, humid environment or acidic environment.

[0005] To solve the above technical problems, the technical solution adopted by the present application is as follows:

[0006] A laser bluing process for high-alloy steel workpiece surface, comprising the following steps:

[0007] Preparation of catalyst; the reagents in the catalyst include ethanol, hydrogen peroxide, hydrochloric acid, sodium carboxymethyl cellulose, fumed nanosilica and deionized water;

[0008] Spray the prepared catalyst on the surface of high-alloy steel workpiece to form a layer of light yellow oxide film on the surface of high-alloy steel workpiece;

[0009] Irradiate the surface of high-alloy steel workpiece with sprayed catalyst with laser to perform bluing treatment, and form a uniform Fe3O4 corrosion-resistant layer on the surface of high-alloy steel workpiece after bluing treatment.

[0010] The further improvement of the technical scheme of the present application is that the volume ratio of each component in the catalyst is as follows: 60-70% of ethanol, 10-12% of hydrogen peroxide, 8-10% of sodium carboxymethyl cellulose solution, 2% of gaseous nanometer silicon dioxide dispersion solution, 8-16% of deionized water and 0.25% of hydrochloric acid.

[0011] The further improvement of the technical scheme of the present application is that the concentration of the sodium carboxymethyl cellulose solution is 0.4%, and the concentration of the gaseous nanometer silicon dioxide dispersion solution is 0.2%.

[0012] The further improvement of the technical scheme of the present application is that the ethanol, the hydrochloric acid and the hydrogen peroxide are all of superior purity.

[0013] The further improvement of the technical scheme of the present application is that the power of the laser is 1000-10000W, the scanning speed is 100-1000mm / s, and the spot size is Φ3-5mm.

[0014] The further improvement of the technical scheme of the present application is that the thickness of the Fe3O4 corrosion-resistant layer is 2-20μm.

[0015] The further improvement of the technical scheme of the present application is that the surface of the high-alloy steel workpiece needs to be degreased and cleaned before being coated with the catalyst.

[0016] Thanks to the above technical scheme, the present application has the following technical progress:

[0017] 1. The present application can effectively improve the light absorption of the surface of the high-alloy steel workpiece by coating the surface with a special catalyst, and a thin and uniform Fe3O4 corrosion-resistant layer can be formed on the surface of the high-alloy steel workpiece by adopting the laser bluing process.

[0018] 2. The catalyst used in the present application contains hydrogen peroxide (H2O2), which can be adsorbed on the surface of the high-alloy steel workpiece and decomposed into oxygen during the laser bluing process, thereby promoting the formation of Fe3O4 and increasing the thickness of the corrosion-resistant layer.

[0019] 3. In the present application, the laser irradiation on the surface of the high-alloy steel workpiece is completed at a power density of 0.5-5.3W / mm 2 The thickness of the corrosion-resistant layer can be controlled by controlling the power density of the laser, and the thickness is 2-20μm.

[0020] 4. The high alloy steel workpiece treated by the blue laser process has a corrosion resistant layer with a thickness of 2-20 microns, can keep from rusting for at least 2 years in dry air, can keep from rusting for at least 1 year in a humid environment, and has no obvious rust after 72 hours of salt spray test (simulating high salt and humid conditions in industrial environment) in a 5% sodium chloride solution at 35℃, thus achieving the purpose of preventing the high alloy workpiece from rusting.

[0021] 5. The catalyst prepared in the application has the advantages of high laser absorption rate, non-toxicity, no environmental pollution, and high cost performance. BRIEF DESCRIPTION OF DRAWINGS

[0022] None. DETAILED DESCRIPTION

[0023] It should be noted that the specification and claims of the application are intended to cover all inclusive, for example, a process, method, system, product or apparatus that includes a series of steps or units need not be limited to only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to such processes, methods, products or apparatus.

[0024] The application will be further described in detail below in combination with examples:

[0025] A laser blue process for the surface of a high alloy steel workpiece, comprising the following steps:

[0026] Step 1, oil removal and cleaning treatment is performed on the surface of the high alloy steel workpiece;

[0027] Step 2, preparation of catalyst:

[0028] The reagents in the catalyst include ethanol, hydrogen peroxide, hydrochloric acid, sodium carboxymethyl cellulose, fumed nanosilica and deionized water; the ethanol, hydrochloric acid and hydrogen peroxide are all of superior purity, and the experimental water meets the requirements in GB / T6682;

[0029] Catalyst preparation: first, 0.4% sodium carboxymethyl cellulose solution is prepared; then, 0.2% fumed nanosilica dispersion liquid is prepared; and then, the catalyst is prepared according to the following volume ratio: ethanol 60-70%, hydrogen peroxide 10-12%, sodium carboxymethyl cellulose solution 8-10%, fumed nanosilica dispersion liquid 2%, deionized water 8-16%, and hydrochloric acid 0.25%;

[0030] Step 3, the prepared catalyst is sprayed on the surface of the high alloy steel workpiece, and a thin layer of light yellow oxide film is formed on the surface of the high alloy steel workpiece;

[0031] Step 4, the laser with power of 1000-10000W, scanning speed of 100-1000mm / s, spot size of Φ3-5mm (i.e. 0.5-5.3W / mm 2 ) is used to irradiate the surface of the high alloy steel workpiece sprayed with catalyst to perform bluing treatment, and a uniform Fe3O4 corrosion-resistant layer with thickness of about 2-20μm is formed on the surface of the high alloy steel workpiece after the bluing treatment is completed.

[0032] Principle:

[0033] After the catalyst is sprayed on the surface of the high alloy steel workpiece, the iron atoms and other metal atoms on the surface of the high alloy steel workpiece are oxidized with the catalyst in the air, hydrochloric acid reacts with the iron atoms on the surface of the high alloy steel workpiece to generate Fe 2+ , and hydrogen peroxide is used as an oxidizing agent to oxidize Fe and Fe 2+ to Fe 3+ , and sodium carboxymethyl cellulose is used as a thickening agent to increase the viscosity of the solution, and the reaction equation is:

[0034] Fe+2H + →Fe 2+ +H2↑

[0035] H2O2+2Fe+6H + →2Fe 3+ +2H2 O+2H2

[0036] 2Fe 2+ H2O2+2H + →2Fe 3+ +2H2 O

[0037] The formed thin film contains Fe3O4 (Fe O·Fe2 O3) and γ-FeOOH (a small amount).

[0038] The thin film is uniform and has good light absorption, and Fe3O4 in the thin film can improve the light absorption of the surface of the high alloy steel workpiece.

[0039] The laser with power of 1000-10000W, scanning speed of 100-1000mm / s, spot size of Φ3-5mm (i.e. 0.5-5.3W / mm 2 ) is used to irradiate the surface of the high alloy steel workpiece to perform bluing treatment. The surface of the high alloy steel workpiece can quickly react with oxygen in the air to generate a dense Fe3O4 corrosion-resistant layer, which is the bluing process. The generated Fe3O4 corrosion-resistant layer has good wear resistance and corrosion resistance, and the method can meet the bluing treatment of high alloy steel workpieces of different sizes.

[0040] The role of the gas-phase nanometer silicon dioxide in the catalyst: laser irradiation on the solid, will be absorbed or reflected. It is tested that the reflectivity of the metal surface to the laser is as high as 70-90%, which will cause the loss of most of the laser energy. The gas-phase nanometer silicon dioxide can increase the light absorption of the catalyst, and under the laser strengthening effect, a gray-black uniform and dense Fe3O4 corrosion-resistant layer is formed.

[0041] It is found through experiments that if the surface of the high-alloy steel workpiece is not coated with the catalyst in the application, a uniform and well-absorbed thin film is not formed, even if oxygen is sprayed to the surface of the high-alloy steel workpiece, the effect of forming the Fe3O4 corrosion-resistant layer is still not ideal, the corrosion-resistant layer is thin and uneven. The reason is analyzed to find that if the Fe3O4 corrosion-resistant layer is to be formed quickly, there need to be Fe 2+ , Fe 3+ ions.

[0042] Example 1

[0043] A laser bluing process for the surface of a high-alloy steel workpiece, comprising the following steps:

[0044] Step 1, oil removal and cleaning treatment is performed on the surface of the high-alloy steel workpiece;

[0045] Step 2, preparing the catalyst:

[0046] First, a sodium carboxymethyl cellulose solution with a concentration of 0.4% is prepared; a gas-phase nanometer silicon dioxide dispersion liquid with a concentration of 0.2% is prepared; then the catalyst is prepared according to the following volume ratio: ethanol 70%, hydrogen peroxide 10%, sodium carboxymethyl cellulose solution 9%, gas-phase nanometer silicon dioxide dispersion liquid 2%, deionized water 8.75%, hydrochloric acid 0.25%; among them, the ethanol, hydrochloric acid and hydrogen peroxide are all of superior grade, and the experimental water meets the requirements of GB / T6682; Step 3, the prepared catalyst is sprayed on the surface of the high-alloy steel workpiece, and a thin layer of light yellow oxide film is formed on the surface of the high-alloy steel workpiece;

[0047] Step 4, the surface of the high-alloy steel workpiece sprayed with the catalyst is irradiated by a laser with a power of 10000W, a scanning speed of 400mm / s and a spot size of Φ5mm to perform bluing treatment, and after the bluing treatment is completed, a uniform Fe3O4 corrosion-resistant layer with a thickness of about 19μm is formed on the surface of the high-alloy steel workpiece.

[0048] The high-alloy steel workpiece is placed in a humid environment for 1 year without any rust.

[0049] Example 2

[0050] A laser bluing process for the surface of a high-alloy steel workpiece, comprising the following steps:

[0051] Step 1, oil removal and cleaning treatment is performed on the surface of the high alloy steel workpiece;

[0052] Step 2, preparation of catalyst:

[0053] First, prepare a 0.4% sodium carboxymethyl cellulose solution; a 0.2% fumed nanosilica dispersion solution; then prepare the catalyst according to the following volume ratio: ethanol 65%, hydrogen peroxide 11%, sodium carboxymethyl cellulose solution 8%, fumed nanosilica dispersion solution 2%, deionized water 13.75%, hydrochloric acid 0.25%;

[0054] Ethanol, hydrochloric acid, hydrogen peroxide are all of superior grade, and the experimental water meets the requirements of GB / T6682;

[0055] Step 3, the prepared catalyst is sprayed on the surface of the high alloy steel workpiece, and a thin layer of light yellow oxide film is formed on the surface of the high alloy steel workpiece;

[0056] Step 4, the surface of the high alloy steel workpiece sprayed with the catalyst is irradiated by a laser with a power of 1000W, a scanning speed of 100mm / s, and a spot size of Φ3mm to perform bluing treatment, and after the bluing treatment is completed, a uniform Fe3O4 corrosion-resistant layer with a thickness of about 10μm is formed on the surface of the high alloy steel workpiece.

[0057] The high alloy steel workpiece is placed in air for 2 years without any rust.

[0058] Example 3

[0059] A high alloy steel workpiece surface laser bluing process, comprising the following steps:

[0060] Step 1, oil removal and cleaning treatment is performed on the surface of the high alloy steel workpiece;

[0061] Step 2, preparation of catalyst:

[0062] First, prepare a 0.4% sodium carboxymethyl cellulose solution; a 0.2% fumed nanosilica dispersion solution; then prepare the catalyst according to the following volume ratio: ethanol 65%, hydrogen peroxide 11%, sodium carboxymethyl cellulose solution 8%, fumed nanosilica dispersion solution 2%, deionized water 13.75%, hydrochloric acid 0.25%;

[0063] Ethanol, hydrochloric acid, hydrogen peroxide are all of superior grade, and the experimental water meets the requirements of GB / T6682;

[0064] Step 3, the prepared catalyst is sprayed on the surface of the high alloy steel workpiece, and a thin layer of light yellow oxide film is formed on the surface of the high alloy steel workpiece;

[0065] Step 4, the surface of the high alloy steel workpiece sprayed with catalyst is irradiated by laser with power of 4000W, scanning speed of 1000mm / s and spot size of Φ4mm to carry out blueing treatment, and a uniform Fe3O4 corrosion resistant layer with thickness of about 4μm is formed on the surface of the high alloy steel workpiece after the blueing treatment is completed.

[0066] The high alloy steel workpiece is subjected to salt spray test (simulating high salt moisture conditions in industrial environment) in 5% sodium chloride solution at 35°C environment, and no obvious rust occurs after 72 hours.

[0067] Comparative Example 1

[0068] The difference from Example 1 is that the surface of the high alloy steel workpiece is directly subjected to laser blueing process treatment after oil removal and cleaning treatment, and the corrosion resistant layer obtained after the blueing process treatment is uneven and extremely thin.

[0069] The high alloy steel workpiece is rusted after being placed in a humid environment for 2 months.

[0070] Comparative Example 2

[0071] The difference from Example 2 is that the surface of the high alloy steel workpiece is directly subjected to laser blueing process treatment after oil removal and cleaning treatment, and the corrosion resistant layer obtained after the blueing process treatment is uneven and extremely thin.

[0072] The high alloy steel workpiece is rusted after being placed in air for 1 year.

[0073] Comparative Example 3

[0074] The difference from Example 3 is that the surface of the high alloy steel workpiece is directly subjected to laser blueing process treatment after oil removal and cleaning treatment, and the corrosion resistant layer obtained after the blueing process treatment is uneven and extremely thin.

[0075] The high alloy steel workpiece is rusted after being subjected to salt spray test (simulating high salt moisture conditions in industrial environment) in 5% sodium chloride solution at 35°C environment for 24 hours.

[0076] The effect comparison table of the above examples and comparative examples is shown in Table 1 as follows:

[0077] Table 1 Effect Comparison Table of Examples and Comparative Examples

[0078]

[0079] As shown in Table 1, the application can effectively improve the light absorption of the high-alloy steel workpiece surface by coating a special catalyst on the surface of the high-alloy steel workpiece, and a thin and uniform Fe3O4 corrosion-resistant layer can be formed on the surface of the high-alloy steel workpiece by adopting the laser bluing process.

[0080] In addition, the upper limit, lower limit and interval value of the process parameters (such as volume ratio, power, scanning speed, spot size, thickness, etc.) of the application can all achieve the application, and the embodiments are not listed one by one.

[0081] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A laser bluing process for the surface of high-alloy steel workpieces, characterized in that: Includes the following steps: A catalyst is prepared; the reagents in the catalyst include ethanol, hydrogen peroxide, hydrochloric acid, sodium carboxymethyl cellulose, fumed silica nanoparticles, and deionized water. The prepared catalyst was sprayed onto the surface of the high alloy steel workpiece, and a light yellow oxide film was formed on the surface of the high alloy steel workpiece. The surface of a high-alloy steel workpiece coated with catalyst is irradiated with a laser to perform a bluing treatment, which forms a uniform Fe3O4 corrosion-resistant layer on the surface of the high-alloy steel workpiece.

2. The laser bluing process for the surface of a high-alloy steel workpiece according to claim 1, characterized in that: The volume ratio of each component in the catalyst is as follows: 60-70% ethanol, 10-12% hydrogen peroxide, 8-10% sodium carboxymethyl cellulose solution, 2% fumed silica nano-dispersion, 8-16% deionized water, and 0.25% hydrochloric acid.

3. The laser bluing process for the surface of a high-alloy steel workpiece according to claim 2, characterized in that: The concentration of the sodium carboxymethyl cellulose solution is 0.4%; the concentration of the fumed silica nano-dispersion is 0.2%.

4. The laser bluing process for the surface of a high-alloy steel workpiece according to claim 2, characterized in that: The ethanol, hydrochloric acid, and hydrogen peroxide are all of analytical grade.

5. The laser bluing process for the surface of a high-alloy steel workpiece according to claim 1, characterized in that: The laser has a power of 1000-10000W, a scanning speed of 100-1000mm / s, and a spot size of Φ3-5mm.

6. The laser bluing process for the surface of a high-alloy steel workpiece according to claim 1, characterized in that: The thickness of the Fe3O4 corrosion-resistant layer is 2-20 μm.

7. The laser bluing process for the surface of a high-alloy steel workpiece according to claim 1, characterized in that: The surface of the high-alloy steel workpiece needs to be degreased and cleaned before the catalyst is coated.

Images