阅读说明：本技术 一种提高奥氏体不锈钢表面耐腐蚀性的方法 (Method for improving surface corrosion resistance of austenitic stainless steel ) 是由 林乃明 张璐霞 邹娇娟 袁烁 刘茹溢 王振霞 秦林 田林海 唐宾 吴玉程 于 2019-11-08 设计创作，主要内容包括：本发明公开了一种提高奥氏体不锈钢表面耐腐蚀性的方法,属于金属材料表面改性技术领域。该处理方法首先对奥氏体不锈钢进行激光表面加工处理,获得花簇状表面形貌,然后采用有机物接枝技术获得复合表面层,最终得到表面改性奥氏体不锈钢。本发明将激光加工处理与有机物接枝技术相结合,对奥氏体不锈钢进行表面处理,使不锈钢表面具有疏水性并提高了奥氏体不锈钢的耐腐蚀性。(The invention discloses a method for improving the surface corrosion resistance of austenitic stainless steel, and belongs to the technical field of surface modification of metal materials. The treatment method comprises the steps of firstly carrying out laser surface processing treatment on austenitic stainless steel to obtain a flower cluster-shaped surface appearance, then adopting an organic matter grafting technology to obtain a composite surface layer, and finally obtaining the surface modified austenitic stainless steel. The invention combines laser processing treatment and organic grafting technology to carry out surface treatment on the austenitic stainless steel, so that the surface of the stainless steel has hydrophobicity and the corrosion resistance of the austenitic stainless steel is improved.)

1. A method for improving the surface corrosion resistance of austenitic stainless steel is characterized in that: the laser processing technology is combined with organic surface grafting, firstly, the austenitic stainless steel is subjected to laser processing treatment to obtain a flower-like surface appearance, and then, the organic chemical grafting technology is adopted to obtain a surface hydrophobic layer, so that the surface corrosion resistance of the austenitic stainless steel is improved.

2. The method of improving the corrosion resistance of an austenitic stainless steel surface according to claim 1, wherein: the method comprises the following steps:

(1) pretreatment of austenitic stainless steel workpieces: degreasing the surface of an austenitic stainless steel workpiece, and then polishing the surface step by using SiC water sand paper;

(2) ultrasonically cleaning a grinded austenitic stainless steel workpiece in absolute ethyl alcohol, washing with distilled water and drying for later use;

(3) carrying out laser processing on the cleaned austenitic stainless steel plate: processing the austenitic stainless steel plate by using a laser scribing machine to obtain the flower cluster-shaped surface appearance, wherein the processing parameters are as follows: the processing focal length is 23-25 mm, the scanning speed is 15-30 mm/s, the output power is 75-95%, and the marking times are 4-6;

(4) preparing a grafting solution: 0.5-2 mol/L sodium hydroxide; 0.5-2 ml of hexadecyl trimethyl siloxane; 10-30 ml of ethanol;

(5) stirring the prepared solution in the step (4) on a magnetic stirrer for 50-70 min;

(6) immersing the austenitic stainless steel processed in the step (3) in the solution stirred in the step (5), wrapping a preservative film on the top of the beaker, and placing the beaker in an oven;

(7) adjusting the temperature of the oven to 40-60 ℃, preserving the heat for 14-18 h, taking out the austenitic stainless steel sheet, and slowly cooling the austenitic stainless steel to room temperature; and carrying out ultrasonic cleaning, distilled water cleaning and drying on the slowly cooled austenitic stainless steel in absolute ethyl alcohol.

3. The method of improving the corrosion resistance of an austenitic stainless steel surface according to claim 2, wherein: in the step (3), the processing focal length of the laser scanning head and the austenitic stainless steel wafer workpiece is 24.1mm, the scanning speed is 20mm/s, the output power is 80%, and the marking times are 5 times.

4. The method of improving the corrosion resistance of an austenitic stainless steel surface according to claim 2, wherein: the surface appearance of the flower clusters in the step (3) is as follows: regularly distributed circular surface features with intervals of 50 mu m, wherein the diameter of the circular units is 20-21 mu m.

5. The method of improving the corrosion resistance of an austenitic stainless steel surface according to claim 2, wherein: the formula of the grafting solution in the step (3) is as follows: 1 mol/L sodium hydroxide; 1 ml of hexadecyl trimethyl siloxane; 20 ml of ethanol; 23 ml of grafting solution was prepared.

6. The method of improving the corrosion resistance of an austenitic stainless steel surface according to claim 2, wherein: the stirring time in the step (5) is 60 min.

7. The method of improving the corrosion resistance of an austenitic stainless steel surface according to claim 2, wherein: the temperature of the oven in the step (7) is 50 ℃, and the heat preservation time is 16 h;

the mixture was washed with distilled water and dried at room temperature.

8. The method of improving the corrosion resistance of an austenitic stainless steel surface according to claim 2, wherein: the laser scribing machine comprises an industrial control computer, a fiber laser, a fiber mirror and a high-speed scanning galvanometer; the industrial control computer outputs data to the optical fiber laser, the energy generated by the optical fiber laser is transmitted to the optical mirror and the high-speed scanning galvanometer by the optical fiber, and then the laser beam with higher energy density is emitted by the high-speed scanning galvanometer to irradiate on the workpiece; the industrial control computer is internally provided with scribing software, can draw target patterns in the scribing software, and can adjust laser parameters.

Technical Field

The invention relates to a method for improving the surface corrosion resistance of austenitic stainless steel, belonging to the technical field of surface modification of metal materials.

Background

The austenitic stainless steel has good comprehensive mechanical property and process property, so that the austenitic stainless steel is widely applied to the fields of industry, civil use, national defense and the like. The austenitic stainless steel is the most various stainless steel and the most used steel, and the production amount and the used amount of the austenitic stainless steel account for about 65-70% of the whole stainless steel production amount. However, due to the disadvantage of poor alkali resistance of the austenitic stainless steel surface, the austenitic stainless steel is generally not used for manufacturing parts in an alkaline aqueous solution environment, and the wider use of the austenitic stainless steel is limited. Based on the fact that corrosion occurs on the surface of the material, studies have shown that the corrosion resistance of austenitic stainless steels can be effectively improved by means of surface techniques. The selection of a proper surface treatment technology has significant meaning for expanding the application of austenitic stainless steel as a corrosion-resistant material. The surface technology is adopted to further improve the surface corrosion resistance of the stainless steel, the requirement of severe environment on the performance of austenitic stainless steel is met, the service life is prolonged, and the production cost is reduced, so that the method has obvious significance.

Disclosure of Invention

The invention aims to provide a method for improving the surface corrosion resistance of austenitic stainless steel, and the obtained austenitic stainless steel has excellent corrosion resistance and prolonged service life.

The invention provides a method for improving the surface corrosion resistance of austenitic stainless steel. The laser surface processing technique is to use the higher heat generated by a laser beam to realize surface processing. The laser scriber is controlled by an industrial control computer, and scribing software is installed in the industrial control computer. Drawing target pattern in the scribing software, outputting data to the fiber laser by the industrial control computer, and transmitting energy to the optical mirror by the fiber laser, wherein the optical mirror is connected with the high-speed scanning galvanometer. The laser beam with higher energy density is emitted by the high-speed scanning galvanometer and irradiated on the surface of the austenitic stainless steel, the surface of the austenitic stainless steel absorbs the laser energy, and a thermal excitation process is generated in an irradiation area, so that the surface temperature of the stainless steel rises, phenomena of metamorphosis, melting, ablation, evaporation and the like are generated, and a surface processing layer is formed on the surface of a workpiece. The laser processing layer is formed because the surface of the metal material is melted and ablated, and the surface roughness of the austenitic stainless steel is improved. The organic solution soaking method has low requirements on implementation conditions, can complete grafting with the metal surface under simple working conditions, and obtains the super-hydrophobic surface with a water contact angle of 158 degrees. The super-hydrophobic surface can reduce the contact area of water and the metal surface, thereby obviously improving the corrosion resistance. The invention innovatively combines the laser processing technology with the organic matter surface grafting, fully exerts the advantages of the two processing technologies, obviously improves the corrosion resistance of the austenitic stainless steel, and has the advantages of super-hydrophobicity and self-cleaning.

The surface treatment method of the stainless steel comprises the following steps:

(1) pretreatment of austenitic stainless steel workpieces: degreasing the surface of an austenitic stainless steel workpiece, and then polishing the surface step by using SiC water sand paper;

(2) carrying out ultrasonic cleaning, distilled water washing and drying on the austenitic stainless steel workpiece with the polished surface in absolute ethyl alcohol for later use;

(3) carrying out laser processing on the cleaned austenitic stainless steel plate: processing the austenitic stainless steel plate by using a laser scribing machine to obtain the flower cluster-shaped surface appearance, wherein the processing parameters are as follows: the processing parameters are as follows: the processing focal length is 23-25 mm, the scanning speed is 15-30 mm/s, the output power is 75-95%, and the marking times are 4-6;

(4) preparing a grafting solution: 0.5-2 mol/L sodium hydroxide; 0.5-2 ml of hexadecyl trimethyl siloxane; 10-30 ml of ethanol;

(5) and (5) stirring the solution prepared in the step (4) on a magnetic stirrer for 50-70 min.

(6) And (4) placing the austenitic stainless steel processed in the step (3) into the solution stirred in the step (5), wrapping a preservative film on the top of the beaker, and placing the beaker in an oven.

(7) And adjusting the temperature of the oven to 40-60 ℃, preserving the heat for 14-18 h, taking out the austenitic stainless steel sheet, and slowly cooling the austenitic stainless steel to room temperature. And carrying out ultrasonic cleaning, distilled water cleaning and drying on the slowly cooled austenitic stainless steel in absolute ethyl alcohol.

(8) And (3) carrying out corrosion resistance detection on the treated austenitic stainless steel workpiece, and carrying out comparison test on an untreated austenitic stainless steel workpiece.

In the processing method, the processing focal length of the laser scanning head and the austenitic stainless steel wafer workpiece in the step (3) is 24.1mm, the scanning speed is 20mm/s, the output power is 80%, and the marking times are 5 times;

in the preparation scheme, the regularly distributed circular surface features with the spacing of 50 mu m in the step (3), wherein the diameter of the circular unit is 20 mu m;

in the above preparation scheme, the formula of the grafting solution in the step (3) is as follows: 1 mol/L sodium hydroxide; 1 ml of hexadecyl trimethyl siloxane; 20 ml of ethanol;

in the preparation scheme, the stirring time in the step (5) is 60 min;

in the preparation scheme, the temperature of the oven in the step (7) is 50 ℃, and the temperature is kept for 16 h.

The invention has the beneficial effects that:

the invention combines the laser treatment and the organic matter grafting technology to carry out surface treatment on the austenitic stainless steel, fully exerts the advantages of the laser treatment and the organic matter grafting and improves the corrosion resistance of the austenitic stainless steel.

Drawings

FIG. 1 is a schematic diagram of a laser scribing apparatus;

FIG. 2 is a surface topography of the treated 304 austenitic stainless steel of example 1;

FIG. 3 is a surface topography map of an untreated 304 austenitic stainless steel;

FIG. 4 is an electrochemical open circuit diagram of example 1(AISI 304), comparative example 1, comparative example 3, and untreated AISI 304;

FIG. 5 is a plot of electrochemical polarization of example 1(AISI 304), comparative example 1, comparative example 3, and untreated AISI 304;

FIG. 6 is a surface topography of the treated 304 austenitic stainless steel of example 2;

FIG. 7 is a surface topography of an untreated 316 austenitic stainless steel;

FIG. 8 is an electrochemical open circuit diagram of example 2(AISI 316), comparative example 2, comparative example 4, and untreated AISI 316;

FIG. 9 is a plot of electrochemical polarization of example 2(AISI 316), comparative example 2, comparative example 4, and untreated AISI 316;

in the figure: 1: an industrial control computer; 2: a fiber laser; 3: an optical fiber; 4: a light mirror; 5: scanning a galvanometer at a high speed; 6: a laser beam; 7: and (5) sampling the workpiece.

Detailed Description

The present invention is further illustrated by, but is not limited to, the following examples.

As shown in fig. 1, the structure of the laser scriber used in the present invention is: comprises an industrial control computer 1, an optical fiber laser 2, an optical mirror 4 and a high-speed scanning galvanometer 5; the processing process comprises the following steps: the industrial control computer 1 outputs data to the optical fiber laser 2, the energy generated by the optical fiber laser 2 is transmitted to the optical mirror 4 and the high-speed scanning galvanometer 5 through the optical fiber 3, and then the laser beam 6 with higher energy density is emitted through the high-speed scanning galvanometer 5 to irradiate on a sample workpiece 7. The industrial control computer is internally provided with scribing software, a target pattern can be drawn in the scribing software, and meanwhile, laser parameters can be adjusted.

The specific embodiments of the present invention will now be described using 304 austenitic stainless steel and 316 austenitic stainless steel as examples: