Preparation method for processing wear-resistant and corrosion-resistant stainless steel surface

Abstract

The invention discloses a preparation method for processing a wear-resistant and corrosion-resistant stainless steel surface. Belongs to the technical field of metal material surface treatment. According to the method, a composite modified layer with excellent wear resistance and corrosion resistance is formed on the surface of stainless steel through the steps of pretreatment, electrochemical modification, magnetron sputtering coating, post-treatment and the like on a stainless steel base material. By optimizing all technological parameters, the treated stainless steel is low in surface roughness and high in film binding force, the chromium oxide film and the electrochemical modified layer act synergistically, the wear resistance and corrosion resistance of the stainless steel are remarkably improved, and the method is suitable for the field with high requirements for material surface performance.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of stainless steel surface treatment, in particular to a preparation method of a wear-resistant and corrosion-resistant stainless steel surface processing. BACKGROUND

[0002] Stainless steel has excellent corrosion resistance and mechanical properties, and is widely used in chemical industry, machinery, medical treatment, food and other fields. However, in some special working conditions, such as high wear and strong corrosion environment, the surface performance of ordinary stainless steel still cannot meet the use requirements, and the surface of the stainless steel is prone to wear and corrosion, which shortens the service life of the material and increases the production cost. In the prior art, various surface treatment methods are adopted, such as electroplating, chemical plating, spraying, ion implantation and the like. However, these methods have some disadvantages, for example, electroplating and chemical plating are easy to cause environmental pollution, the adhesion between the coating and the substrate is not ideal, the sprayed coating has a high porosity, and the ion implantation equipment is expensive and has a limited processing area. Therefore, the application provides a preparation method of wear-resistant and corrosion-resistant stainless steel surface processing. SUMMARY

[0003] In order to solve the above problems, the application provides a preparation method of wear-resistant and corrosion-resistant stainless steel surface processing. The application solves the problems in the prior art that various surface treatment methods are adopted, such as electroplating, chemical plating, spraying, ion implantation and the like. However, these methods have some disadvantages, for example, electroplating and chemical plating are easy to cause environmental pollution, the adhesion between the coating and the substrate is not ideal, the sprayed coating has a high porosity, and the ion implantation equipment is expensive and has a limited processing area.

[0004] The preparation method of the wear-resistant and corrosion-resistant stainless steel surface processing in the application is performed according to the following steps to obtain a wear-resistant and corrosion-resistant modified layer on the surface of the stainless steel: S1, the surface of the stainless steel substrate is polished by using 180#-800# silicon carbide sandpaper in stages until the roughness Ra is less than or equal to 0.2 microns, and the surface is cleaned by sequentially using acetone, alcohol and deionized water to obtain a pretreated stainless steel material, and the substrate is immersed in an alkaline degreasing solution at 50 DEG C and ultrasonically cleaned for 20 minutes, and then washed with deionized water for three times; S2, the stainless steel substrate is immersed in a 10% hydrochloric acid solution at room temperature for 5 minutes, washed with deionized water immediately after the oxide skin is removed until the pH value is 7, and dried in a vacuum drying oven at 80 DEG C for 30 minutes to avoid secondary pollution. S3, the pretreated stainless steel is used as an anode, graphite is used as a cathode, the distance between the anode and the cathode is controlled to be 50 mm, a mixed aqueous solution of citric acid 35 g / L + boric acid 20 g / L is used as a base solution, a composite additive is added, and the pH value is adjusted to 4.0. S5, the stainless steel substrate is placed in an electrolyte, the current density is controlled to be 300 A / m2, the electrolyte temperature is 40 DEG C, the constant current polarization treatment is 9 min, the substrate is taken out and cleaned with deionized water for 10 min, and the residual electrolyte on the surface is removed. S6, the electrochemically modified substrate is placed into a magnetron sputtering furnace, vacuum is extracted to 5*10-6 Pa, and a chromium oxide film with a thickness of 3 microns is formed on the surface of the stainless steel substrate. 4 Pa, a pure chromium target is used, argon and oxygen are introduced, and the flow ratio is controlled to be 13:5; S7, the substrate temperature is 150 DEG C, the sputtering power is 200 W, the deposition time is 60 min, the stainless steel substrate surface forms a chromium oxide film with a thickness of 3 microns, and the vacuum state is maintained to cool to room temperature, avoiding coating oxidation; S8, the coated substrate is placed in a vacuum tempering furnace, 200 DEG C is kept for 2h, internal stress is eliminated, the substrate is immersed in a silane coupling agent solution at room temperature for 15 min, a molecular level sealing layer is formed, and 60 DEG C hot air drying is performed for 10 min, and the preparation is completed.

[0005] In the above scheme, the stainless steel substrate is 304, 30Cr15Mo1N.

[0006] In the above scheme, the alkaline degreasing solution is sodium hydroxide 15g / L + sodium carbonate 20g / L + surfactant 3g / L.

[0007] In the above scheme, the composite additive is zinc citrate 5g / L + manganese nitrate 0.8g / L.

[0008] In the above scheme, the purity of the pure chromium target is 99.95%.

[0009] In the above scheme, the concentration of the silane coupling agent solution is 5%.

[0010] The advantages and beneficial effects of the present application are that the present application provides a preparation method for wear-resistant and corrosion-resistant stainless steel surface processing, the present application gradually polishes and multi-step cleans to make the stainless steel substrate surface reach a lower roughness, provides a clean and uniform substrate for subsequent processing, and is beneficial to improve the adhesion between the modified layer and the substrate. Electrochemical modification treatment is adopted to form a uniform modified layer on the surface of the stainless steel, the modified layer is firmly combined with the substrate, and a good adhesion foundation is provided for subsequent magnetron sputtering coating. The chromium oxide film prepared by magnetron sputtering has high hardness and wear resistance, and can significantly improve the wear resistance of the stainless steel surface; at the same time, the chromium oxide film has good chemical stability, and can improve the corrosion resistance of the stainless steel. The vacuum tempering in the post-processing step can eliminate the internal stress generated in the coating process and improve the stability of the film; the silane coupling agent sealing treatment can effectively fill the micropores and defects on the surface of the film, further block the penetration path of the corrosion medium, and improve the corrosion resistance of the stainless steel. DETAILED DESCRIPTION

[0011] The specific embodiments of the present application are further described below in conjunction with examples. The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application. Embodiment

[0012] The present application is a preparation method of a wear-resistant and corrosion-resistant stainless steel surface processing, comprising the following steps: S1, substrate pretreatment: 304 stainless steel is selected as the substrate, and the surface of the stainless steel substrate is polished by using 180#, 320#, 500# and 800# silicon carbide sandpaper in sequence until the roughness Ra=0.15μm, and then the surface is cleaned by ultrasonic cleaning with acetone, alcohol and deionized water for 15min respectively, and the pretreated stainless steel material is obtained. The substrate is immersed in an alkaline degreasing solution (sodium hydroxide 15g / L + sodium carbonate 20g / L + surfactant 3g / L) at 50℃ for ultrasonic cleaning for 20min, and then washed with deionized water for 3 times; S2, pickling and drying: the stainless steel substrate treated in step S1 is immersed in a 10% hydrochloric acid solution at room temperature for 5min, and then washed with deionized water immediately after removing the oxide skin until the pH value is 7, and then dried in a vacuum drying oven at 80℃ for 30min; S3, electrochemical modification preparation: the stainless steel pretreated in step S2 is used as an anode, graphite is used as a cathode, the distance between the anode and the cathode is controlled to be 50mm, the basic solution is a mixed aqueous solution of citric acid 35g / L + boric acid 20g / L, and a composite additive (zinc citrate 5g / L + manganese nitrate 0.8g / L) is added, and the pH value is adjusted to 4.0; S4, electrochemical modification treatment: the stainless steel substrate prepared in step S3 is placed in the electrolyte, the current density is controlled to be 300A / m², the electrolyte temperature is 40℃, and the constant current polarization treatment is carried out for 9min, then the substrate is taken out and ultrasonically cleaned with deionized water for 10min to remove the residual electrolyte on the surface; S5, magnetron sputtering preparation: the substrate after electrochemical modification in step S4 is placed in a magnetron sputtering furnace, and vacuumized to 5×10⁻ 4 Pa, a pure chromium target with a purity of 99.95% is used, argon and oxygen are introduced, and the flow ratio is controlled to be 13:5; S6, magnetron sputtering coating: the substrate temperature is controlled to be 150℃, the sputtering power is 200W, the deposition time is 60min, and a chromium oxide film with a thickness of 3μm is formed on the surface of the stainless steel substrate, and then the vacuum state is maintained to cool to room temperature; S7, post-treatment: the substrate after coating in step S6 is placed in a vacuum tempering furnace, and then heat treated at 200℃ for 2h to eliminate internal stress, and then immersed in a 5% silane coupling agent solution at room temperature for 15min to form a molecular level sealing layer, and then hot air dried at 60℃ for 10min to complete the preparation. Embodiment

[0013] A method for preparing a wear-resistant and corrosion-resistant stainless steel surface processing, comprising the following steps: S1, substrate pretreatment: 30Cr15Mo1N stainless steel is selected as the substrate, and the surface of the stainless steel substrate is polished by using 180#, 320#, 500# and 800# silicon carbide sandpaper in sequence until the roughness Ra=0.18μm, and then the surface is cleaned by sequentially ultrasonic cleaning with acetone, alcohol and deionized water for 15min each, and the substrate is immersed in an alkaline degreasing solution (15g / L of sodium hydroxide+20g / L of sodium carbonate+3g / L of surfactant) at 50℃ for ultrasonic cleaning for 20min, and then washed with deionized water for 3 times; S2, pickling and drying: the stainless steel substrate treated in step S1 is immersed in a 10% hydrochloric acid solution at room temperature for 5min, and then washed with deionized water immediately after removing the oxide skin until the pH value is 7, and then dried in a vacuum drying oven at 80℃ for 30min; S3, electrochemical modification preparation: the stainless steel pretreated in step S2 is used as an anode, graphite is used as a cathode, the distance between the anode and the cathode is controlled to be 50mm, the basic solution is a mixed aqueous solution of 35g / L of citric acid and 20g / L of boric acid, and a composite additive (5g / L of zinc citrate and 0.8g / L of manganese nitrate) is added, and the pH value is adjusted to 4.0; S4, electrochemical modification treatment: the stainless steel substrate prepared in step S3 is placed in an electrolyte, the current density is controlled to be 300A / m², the temperature of the electrolyte is 40℃, and the stainless steel substrate is treated by constant current polarization for 9min, then the stainless steel substrate is taken out and ultrasonically cleaned with deionized water for 10min to remove the residual electrolyte on the surface; S5, magnetron sputtering preparation: the stainless steel substrate treated by electrochemical modification in step S4 is placed in a magnetron sputtering furnace, the vacuum degree is controlled to be 5×10⁻ 4 Pa, a pure chromium target with a purity of 99.95% is used, argon and oxygen are introduced, and the flow ratio is controlled to be 13:5; S6, magnetron sputtering coating: the temperature of the substrate is controlled to be 150℃, the sputtering power is 200W, the deposition time is 60min, a chromium oxide film with a thickness of 3μm is formed on the surface of the stainless steel substrate, and the vacuum state is maintained to cool to room temperature; S7, post-treatment: the substrate coated in step S6 is placed in a vacuum tempering furnace, heated at 200℃ for 2h to eliminate internal stress, immersed in a 5% silane coupling agent solution at room temperature for 15min to form a molecular level sealing layer, and then hot air dried at 60℃ for 10min to complete the preparation.

[0014] The stainless steel samples prepared in the above embodiment 1 and embodiment 2 are tested for performance, and the results show that the hardness of the stainless steel surface treated by the method of the present application is significantly improved, the wear resistance is better than that of untreated stainless steel; in the salt spray test, the corrosion resistance time is significantly prolonged, and the corrosion resistance is significantly improved The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a wear-resistant and corrosion-resistant stainless steel surface, characterized in that, The method for obtaining a wear-resistant and corrosion-resistant modified layer on a stainless steel surface is performed according to the following steps: S1. Use 180#-800# silicon carbide sandpaper to grind the surface of the stainless steel substrate step by step until the roughness Ra≤0.2μm. Then use acetone, alcohol and deionized water to perform ultrasonic cleaning in sequence to clean the surface and obtain the pretreated stainless steel material. Immerse the substrate in 50℃ alkaline degreasing solution for ultrasonic cleaning for 20min and rinse with deionized water 3 times. S2. Immerse the stainless steel substrate in a 10% hydrochloric acid solution at room temperature for 5 minutes to remove the oxide scale. Immediately rinse with deionized water until pH=7, and dry in an 80℃ vacuum drying oven for 30 minutes to avoid secondary contamination. S3. Using pretreated stainless steel as the anode and graphite as the cathode, the electrode distance is controlled at 50 mm. The base solution is a mixed aqueous solution of citric acid 35 g / L + boric acid 20 g / L. Add composite additives and adjust the pH to 4.

0. S5. The stainless steel substrate is placed in the electrolyte, the current density is controlled at 300A / m², the electrolyte temperature is 40℃, and constant current polarization treatment is performed for 9 minutes. The substrate is then removed and ultrasonically cleaned with deionized water for 10 minutes to remove residual electrolyte from the surface. S6. Place the electrochemically modified substrate into a magnetron sputtering furnace and evacuate to a vacuum level of 5×10⁻⁻⁻⁻⁵. 4 Pa, using a pure chromium target, is introduced with argon and oxygen in a flow ratio controlled at 13:5; S7, substrate temperature 150℃, sputtering power 200W, deposition time 60min, a 3μm thick chromium oxide film is formed on the surface of the stainless steel substrate, and the substrate is kept in a vacuum state and cooled to room temperature to avoid coating oxidation. S8. Place the coated substrate in a vacuum tempering furnace and keep it at 200°C for 2 hours to eliminate internal stress. Immerse it in a silane coupling agent solution at room temperature for 15 minutes to form a molecular-level sealing layer. Dry it with hot air at 60°C for 10 minutes to complete the preparation.

2. The method for preparing a wear-resistant and corrosion-resistant stainless steel surface finish according to claim 1, characterized in that, The stainless steel substrate is 304 or 30Cr15Mo1N.

3. The method for preparing a wear-resistant and corrosion-resistant stainless steel surface according to claim 1, characterized in that, The alkaline degreasing solution consists of 15 g / L sodium hydroxide + 20 g / L sodium carbonate + 3 g / L surfactant.

4. The method for preparing a wear-resistant and corrosion-resistant stainless steel surface according to claim 1, characterized in that, The composite additive is 5 g / L zinc citrate + 0.8 g / L manganese nitrate.

5. The method for preparing a wear-resistant and corrosion-resistant stainless steel surface finish according to claim 1, characterized in that, The purity of the pure chromium target is 99.95%.

6. The method for preparing a wear-resistant and corrosion-resistant stainless steel surface according to claim 1, characterized in that, The concentration of the silane coupling agent solution is 5%.