CN105603502B - A method for degreasing metal plate surface - Google Patents

Abstract

The invention relates to the field of metal plate surface treatment, and discloses a method for degreasing the metal plate surface, wherein the method includes electrochemically polishing the metal plate surface in an electrolyte solution containing 5-15% by weight of sulfuric acid. Through the above technical scheme, the following technical effects can be achieved: the traditional HF solution immersion and the impact on the human body and the environment are reduced, and the influence of the traditional immersion or spray degreasing degreasing liquid residual liquid on the subsequent surface treatment process is reduced. It is possible to use regular parts in the home appliance industry; the production process is simple and easy to operate; when the surface of the titanium alloy plate degreased by this process is anodized, the voltage used to obtain the same color in the same solution concentration is lower, so that It will greatly reduce the cost of electricity.

Description

A method for degreasing metal plate surface

technical field

The invention relates to the field of metal plate surface treatment, in particular to a method for degreasing the surface of a metal plate.

Background technique

At present, domestic and foreign manufacturers will form a dense oxide layer on the surface during the production of titanium and titanium alloy plates. This oxide layer is difficult to remove during subsequent surface anodic oxidation treatment or other surface process construction. The traditional treatment method is to soak the surface of titanium and titanium alloy plates with HF solution or use a polishing machine to polish the surface of the plate, and then soak in HF solution to completely remove the oxide layer on the surface, and then perform surface treatment, etc. process.

However, because HF solution is highly corrosive, highly polluting and highly volatile, it will cause serious harm to the environment and the body of the staff. It is not suitable for large-scale industrial production of household appliances. In addition, the process of polishing the surface of titanium plate or titanium alloy plate by polishing machine is not suitable for the production of large household appliances and irregular parts. Titanium and titanium alloy plates of Panzhihua Iron & Steel are mainly used in rice cooker liners, microwave oven liners and various household appliance parts in the domestic large-scale home appliance manufacturing industry. Household appliance companies need a new type of pretreatment process that is less harmful to the environment, low in cost, easy to operate and suitable for mass production.

Moreover, due to the irregular surface of the metal plate, the traditional degreasing methods, such as spray degreasing or soaking degreasing, will cause "water accumulation" or "fluid accumulation" in other parts, resulting in the deposition of degreasing liquid, which will affect the subsequent various surface treatments. Work.

Contents of the invention

The purpose of the present invention is to overcome the above defects and provide a method for degreasing the surface of metal plates. The method has the characteristics of low cost, low environmental hazards, and is suitable for polishing of irregular parts. The surface of the metal plate avoids the phenomenon of "water accumulation" or "liquid accumulation".

In order to achieve the above object, the present invention provides a method for degreasing the surface of a metal plate, wherein the method includes electrochemically polishing the surface of the metal plate in an electrolyte solution containing 5-15% by weight of sulfuric acid.

Preferably, the electrochemical polishing time is 120-250s, the voltage is 1-10V, and the current density is 0.35-0.65A/cm ² .

Preferably, the method further includes the step of washing the electrochemically polished metal plate according to any one of claims 1-3. The water washing includes at least three water washing steps, wherein the first time is spray water washing, the second time is immersion water washing, and the third time is spray water washing.

Preferably, before the electrochemical polishing treatment, the method further includes grinding the surface of the metal plate, and the conditions of grinding are such that the roughness of the surface of the metal plate is 1.5-0.8 μm.

Through the above technical scheme, the following technical effects can be achieved:

(1) By the method of the present invention, the immersion of the traditional HF solution and the impact on the human body and the environment are reduced, and it is more suitable for irregular parts;

(2) After degreasing by this process, the surface grease is removed, which reduces the influence of the traditional soaking or spraying degreasing degreasing liquid residual liquid on the subsequent surface treatment process, making it possible for irregular parts to be used in the home appliance industry;

(3) The present invention uses simple production process and easy operation;

(4) When the surface of the titanium alloy plate degreased by this process is anodized, in the same solution concentration, the voltage used to obtain the same color is lower, which will greatly reduce the cost of electricity;

(5) Take Panzhihua Iron and Steel Titanium as an example. Panzhihua Iron and Steel has started rolling titanium products since 2010, with a designed annual production capacity of 10,000 tons. The profit of titanium plate is calculated at 5,000 yuan, and the new benefits of this technology are shown in the following formula (10,000 yuan);

Y - the annual benefits generated by using this surface treatment technology;

A-Sales profit per ton of titanium sheet: 5,000 yuan/ton;

T-The total tonnage of titanium plates used in the household appliance industry per year: 3,000 tons;

Then: Y=A×T=3000×5000=1500 (10,000 yuan).

Other features and advantages of the present invention will be described in detail in the detailed description that follows.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, together with the following specific embodiments, are used to explain the present invention, but do not constitute a limitation to the present invention. In the attached picture:

Figure 1 is a picture of a titanium plate of pure titanium without any treatment.

Fig. 2 is a picture of the surface of the titanium plate after spraying treatment according to a specific embodiment of the present application.

Fig. 3 is a picture of the surface of a titanium plate after electrochemical polishing treatment according to a specific embodiment of the present invention.

detailed description

Specific embodiments of the present invention will be described in detail below. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

Oil stains are almost unavoidable on the surface of metal parts. There are three types of oil stains, namely mineral oil, vegetable oil and animal oil. According to the chemical properties of oil, it can be divided into: saponifiable oil and unsaponifiable oil. The chemical components of all animal oils and vegetable oils are mainly fatty acids and glycerides. Since they can react with alkali to form soap, they are called saponifiable oils; the chemical components of mineral oil are various hydrocarbons, which cannot react with alkali, so It is called unsaponifiable oil. Commonly used degreasing methods are: organic solvent degreasing, chemical degreasing and electrochemical degreasing. In the process of research, the inventors of the present invention further found that due to the irregularity of the metal surface, the traditional degreasing method will have "water accumulation" or "fluid accumulation" in other parts, resulting in the deposition of degreasing liquid and affecting various subsequent surfaces. Treatment work, for example, can increase the voltage of anodic oxidation, and the inventors of the present invention have further found that selecting the electrolytic solution as an electrolytic solution containing 5-15% by weight, preferably 8-12% by weight, of sulfuric acid can effectively avoid "Water accumulation" or "fluid accumulation" on the surface of the plate can be eaten, and also reduce the voltage to obtain the same color pattern in the subsequent anodizing process.

Based on the above findings, the present invention provides a method for degreasing the surface of a metal plate, wherein the method includes electrochemically polishing the surface of the metal plate in an electrolyte solution containing 5-15% by weight of sulfuric acid.

Preferably, the electrolyte is an electrolyte containing 8-12% by weight of sulfuric acid.

According to the present invention, the conditions for performing electrochemical polishing on the metal plate can be conventional electrochemical polishing conditions in this field, for example, the time of electrochemical polishing is 120-250s, the voltage is 1-10V, and the current density is 0.35-0.65 A/cm ² . Further preferably, the electrochemical polishing time is 150-220s, the voltage is 3-8V, and the current density is 0.45-0.55A/cm ² .

According to the degreasing method of the present invention, when the metal parts are immersed in the electrolytic tank, the interfacial tension between the oil and the dilute sulfuric acid in the electrolyte will be greatly reduced, and cracks will be formed in the oil film. At the same time, due to the polarization of the electrode due to the electrification, the surface tension between the electrode and the electrolyte decreases, and the wettability of the solution to the metal surface increases, and the solution squeezes the oil film from the discontinuity and crack of the oil film. The method of the present invention is preferably cathodic degreasing, that is, the sample is used as a cathode, and the cathode releases hydrogen: 4H ₂ O+4e ⁻ →2H ₂ ↑+4OH ⁻ . Among them, the hydrogen escapes in the form of a large number of small bubbles, which has a strong stirring and impact effect on the solution, so the oil film is torn and dispersed into many small oil droplets. At the same time, the small bubbles are easy to stay on the oil droplets. , when the bubble grows to a certain size, it will rise to the surface of the solution with small oil droplets. Therefore, the surface polishing treatment of the metal plate is effectively realized.

According to the present invention, the anode used for the above cathodic degreasing can be various inert anodes known in the art, for example, graphite, platinum and the like.

According to the present invention, preferably, the present invention also includes the step of washing the metal plate after the electrochemical polishing treatment, and the washing can be a conventional cleaning method in the field, for example, soaking and/or spraying can be used. Further preferably, the water washing method includes at least 3 times of water washing, wherein the first time is spray water washing, the second time is immersion water washing, and the third time is spray water washing. Wherein, the temperature of the water washing is preferably 65-75° C., for the spray water washing, the spray pressure is preferably 1-1.5 MPa, and for the immersion water washing, the soaking time is preferably 5-10 min.

According to the present invention, the metal plate can be any metal plate that needs to be degreased, for example, it can be a titanium plate, a titanium alloy plate, and the like.

According to the present invention, preferably, the step of surface grinding the metal plate is further included before the degreasing, and the conditions of the grinding are preferably such that the surface roughness of the metal plate is 1.5-0.8 μm. Wherein, the grinding method may be any grinding method known in the art, as long as the above roughness can be ensured. For example, it can be polished with a polishing machine, or shot blasted with a shot blasting machine. But as mentioned above, since the degreasing treatment of the present invention can reduce the phenomenon of "water accumulation" or "liquid accumulation" on the surface of the metal plate, the method of the present invention is particularly suitable for the degreasing treatment of the surface of the metal plate after shot blasting.

According to the present invention, the method of shot blasting treatment can be a conventional choice in this field. For example, according to a preferred embodiment of the present invention, the method of shot blasting treatment includes: using particles with a particle size less than or equal to 1 mm to The plates are sprayed at a pressure of 1-4 MPa per square meter of metal plate.

The inventors of the present invention found in the process of research that before the degreasing treatment of the metal plate, the metal plate is sprayed by using particles with a particle size not greater than 1mm, and, with respect to the metal plate per square meter, the particle size is controlled. The crushing pressure of the metal plate is 1-4MPa, which can effectively remove the undesired components (such as rust or other pollutants) such as the oxide layer on the surface, and achieve the polishing treatment of the metal plate surface. And the metal plate after this treatment can achieve uniform roughness and gloss. Further preferably, the pressure is 1.5-3 MPa.

According to the invention, the particles are preferably sand particles or steel balls.

Although the purpose of the present invention can be achieved by spraying the metal plate in the above manner, the inventor of the present invention surprisingly found in the process of research that by setting the particles to 3 different levels of particle diameters, the processed The surface contamination of the metal plate can be further removed, and the surface roughness and gloss are more uniform, which is more conducive to the subsequent anodic oxidation treatment. Wherein, preferably, the particle size of the large particle size particles is 0.6-0.8 mm, the particle size of the medium particle size particles is 0.2-0.5 mm, and the particle size of the small particle size particles is 0.1-0.15 mm.

According to the present invention, under the preferred situation as above, the ratio of large-sized particles, medium-sized particles and small-sized particles can be adjusted within a wide range, and in a further preferred situation, the proportion of medium-sized particles is the largest , and more preferably greater than the sum of the proportions of small and large particle sizes. Most preferably, the ratio of the large-size particles, medium-size particles and small-size particles is 1:(3-6):(0.5-1.2), preferably 1:(4-5):(0.65-1). In this preferred situation, the pollutants (eg, oxide layer) on the surface of the metal plate can be removed more thoroughly, making the roughness and gloss of the surface of the metal plate more uniform.

According to the present invention, the throwing order of the particles in different particle size ranges is not too limited, they can be thrown at the same time, or can be thrown successively according to the size of the particles. When the metal surface is treated with large-sized particles first, and then the metal surface is treated with medium-sized and small-sized particles, the performance of the obtained metal plate can be further improved.

According to the present invention, relative to the metal plate per square meter, the density of the particles can also be selected within a wide range, but considering factors such as the polishing effect and damage degree of the metal plate, relative to the metal plate per square meter Metal plate, the throwing density of the particles is 60-95kg.

According to the present invention, preferably, the present invention also includes the step of washing the metal plate after the spray treatment, and the washing can be a conventional cleaning method in the field, for example, soaking and/or spraying can be used. Further preferably, the water washing method includes at least 3 times of water washing, wherein the first time is spray water washing, the second time is immersion water washing, and the third time is spray water washing. Wherein, the temperature of the water washing is preferably 65-75° C., for the spray water washing, the spray pressure is preferably 1-1.5 MPa, and for the immersion water washing, the soaking time is preferably 5-10 min.

According to the present invention, in the case of preferred shot blasting as above, the thickness of the metal plate is preferably greater than 2 mm.

According to the present invention, in a further preferred situation, the method of the present invention also preferably carries out the step of soaking the metal plate in an organic solvent after the shot blasting treatment and before degreasing, and the organic solvent is preferably selected from gasoline, kerosene, toluene , trichloroethane, tetrachloroethane in one or more. Wherein, the soaking time can be selected within a wide range, preferably 3-10 minutes, and further preferably, the soaking is preferably performed under ultrasonic conditions.

The present invention will be described in detail below by way of examples.

Example 1

This embodiment is used to illustrate the degreasing method of the metal plate surface provided by the present invention

(1) Spray treatment

Put the irregular titanium plate with a thickness of 5mm into the shot blasting machine for shot blasting treatment, fill the shot blasting machine with 15% steel balls with a particle size of 0.8mm, 75% of pellets with a particle size of 0.3mm, and 10% The pellets with a particle size of 0.1mm, wherein, relative to each square meter of metal plate, the shot blasting pressure is 2MPa, and the particle density is 70kg. Among them, the blasting treatment of large-sized particles is carried out first, and then the spraying treatment of medium-sized and small-sized particles is carried out. The surface roughness of the titanium plate after treatment is determined to be between 1.0-0.8 μm.

(2) Purification treatment 1

The titanium plate after the treatment in step (1) was washed with water for 3 times, wherein the first and third times were spray washing, the water temperature was 70°C, and the water pressure was 1MPa, and the second time was immersion washing, wherein the water temperature was 70℃, soaking time is 5min;

Wherein, the surface of the titanium plate before spray treatment is shown in FIG. 1 , and the surface of the titanium plate after spraying and water washing is shown in FIG. 2 .

(3) Degreasing treatment

The titanium plate washed with water in step (2) was used as cathode, 10% by weight dilute sulfuric acid solution was used as electrolyte, and graphite was used as anode for electrochemical polishing for 180s, wherein the voltage was 5V and the current density was 0.5A/cm ² .

(4) Repeat the water washing step of step (2) to obtain the polished titanium plate of the present invention.

The surface of the titanium plate after degreasing treatment is shown in Figure 3.

Example 2

This embodiment is used to illustrate the method for degreasing the metal plate surface provided by the present invention

(1) Spray treatment

Put the irregular titanium plate with a thickness of 8mm into the shot blasting machine for shot blasting treatment, fill the shot blasting machine with 17% steel balls with a particle size of 0.6mm, 68% with pellets with a particle size of 0.4mm, and 15% The pellets with a particle size of 0.15mm, wherein, relative to each square meter of metal plate, the shot blasting pressure is 3MPa, and the particle density is 65kg. Among them, the blasting treatment of large-sized particles is carried out first, and then the spraying treatment of medium-sized and small-sized particles is carried out. The surface roughness of the titanium plate after treatment is determined to be between 1.2-1.0 μm.

(2) Purification treatment 1

The titanium plate after step (1) was washed with water for 3 times, wherein the first and third times were spray washing, wherein the water temperature was 65°C and the water pressure was 1.2MPa, and the second time was immersion washing, wherein , the water temperature is 75°C, and the soaking time is 8 minutes;

(3) Degreasing treatment

The titanium plate washed with water in step (2) was used as cathode, 8% by weight dilute sulfuric acid solution was used as electrolyte, and graphite was used as anode for electrochemical polishing for 220s, wherein the voltage was 3V and the current density was 0.55A/cm ² .

(4) Repeat the water washing step of step (2) to obtain the polished titanium plate of the present invention.

Example 3

This embodiment is used to illustrate the method for degreasing the metal plate surface provided by the present invention

(1) Spray treatment

Put the irregular titanium plate with a thickness of 2mm into the shot blasting machine for shot blasting treatment, fill the shot blasting machine with 15% steel balls with a particle size of 0.65mm, 70% of pellets with a particle size of 0.2mm, and 15% The pellets with a particle size of 0.1mm, the shot blasting pressure is 1.5MPa, and the particle density is 70kg per square meter of metal plate. Among them, the blasting treatment of large-sized particles is carried out first, and then the spraying treatment of medium-sized and small-sized particles is carried out. The surface roughness of the titanium plate after treatment is determined to be between 1.3-1.1 μm.

(2) Purification treatment 1

The titanium plate after step (1) was washed with water for 3 times, wherein the first and third times were spray washing, wherein the water temperature was 75°C and the water pressure was 1.0MPa, and the second time was immersion washing, wherein , the water temperature is 65°C, and the soaking time is 5 minutes.

(3) Degreasing treatment

The titanium plate washed with water in step (2) was used as cathode, 12% by weight dilute sulfuric acid solution was used as electrolyte, and graphite was used as anode for electrochemical polishing for 150s, wherein the voltage was 8V and the current density was 0.45A/cm ² .

(4) Repeat the water washing step of step (2) to obtain the polished titanium plate of the present invention.

Example 4

This embodiment is used to illustrate the method for degreasing the metal plate surface provided by the present invention

The polishing treatment of the surface of the metal plate is carried out according to the method of Example 1, the difference is that in step (1), the particles are of two different particle sizes, wherein 0.2mm occupies 20%, and 0.4mm occupies 80%. The surface roughness of the titanium plate after shot blasting is determined to be between 1.5-0.8 μm.

Example 5

This embodiment is used to illustrate the method for degreasing the metal plate surface provided by the present invention

Carry out the polishing process on the surface of the metal plate according to the method of Example 1, the difference is that the water washing in steps (2) and (4) all adopts soaking water washing for the first time, and spray water washing for the second and third times.

Example 6

This embodiment is used to illustrate the method for degreasing the metal plate surface provided by the present invention

The polishing treatment of the surface of the metal plate is carried out according to the method of Example 1, the difference is that in step (1), the spraying treatment of the medium-sized and small-sized particles is carried out first, and then the spraying treatment of the large-sized particles is carried out. The surface roughness of the titanium plate after treatment is determined to be between 1.5-0.8 μm.

Example 7

This embodiment is used to illustrate the method for degreasing the metal plate surface provided by the present invention

The degreasing treatment of the surface of the metal plate was carried out according to the method of Example 1, the difference was that the step of shot blasting was not carried out, but the metal plate was polished by a polishing machine.

Example 8

This embodiment is used to illustrate the method for degreasing the metal plate surface provided by the present invention

Carry out the degreasing treatment on the surface of the metal plate according to the method of Example 1, the difference is that a gasoline soaking step is added between steps (2) and (3), and the soaking time is 5 minutes.

Comparative example 1

This comparative example is used to illustrate the method of degreasing the surface of the metal plate provided by the reference

Carry out the degreasing treatment of the surface of the metal plate according to the method of Example 1, the difference is that in step (3), the degreasing is gasoline degreasing. That is, the titanium plate treated in step (2) is soaked in gasoline for degreasing treatment, and the soaking time is 5 minutes.

Comparative example 2

This comparative example is used to illustrate the method of degreasing the surface of the metal plate provided by the reference

Carry out degreasing treatment on the surface of the metal plate according to the method of Example 1, the difference is that the electrolyte in step (3) is 10% phosphoric acid.

Comparative example 3

This comparative example is used to illustrate the method of degreasing the surface of the metal plate provided by the reference

Carry out degreasing treatment on the metal plate surface according to the method of embodiment 1, difference is, the electrolytic solution in the step (3) is to contain 500g/L dehydrated alcohol, 400gg/L lactic acid, 88g/L perchloric acid and 7.5g/L L sodium perchlorate electrolyte.

test case 1

Sensory evaluation of surface roughness, gloss and water accumulation of titanium plate

Select 5 senior personnel in the field to evaluate the surface roughness and gloss uniformity of the titanium plates obtained in Examples 1-9 and Comparative Examples 1-3, and evaluate the water accumulation in the titanium plates after washing. Among them, the surface roughness and gloss are very uniform as 5 points, relatively uniform as 4 points, generally 3 points, relatively uneven as 2 points, and very uneven as 1 point. 5 points for no stagnant water, 4 points for careful identification of slight stagnant water, 3 points for visible stagnant water, 2 points for a lot of stagnant water, and 1 point for overflowing stagnant water. The final result is calculated by the average score of each group, and the results are shown in Table 1.

Table 1

roughness Gloss Situation of stagnant water Example 1 4.6 4.7 4.9 Example 2 4.6 4.6 4.7 Example 3 4.5 4.8 4.7 Example 4 4.3 4.2 4.1 Example 5 4.6 4.6 4.5 Example 6 3.9 4.0 3.8 Example 7 4.0 3.9 3.0 Example 8 4.9 5.0 5.0 Comparative example 1 4.5 4.5 3.5 Comparative example 2 4.3 4.4 3.2 Comparative example 3 4.1 4.0 3.9

Wherein, since the test object of the present invention is an irregular titanium plate, as can be seen from Example 7, after adopting the existing polishing machine to carry out polishing treatment, because the polishing machine cannot penetrate into the dead angle position of the titanium plate for processing, therefore , the gloss uniformity of the final obtained titanium plate is poor, and the phenomenon of water accumulation is also relatively serious.

test case 2

Follow the steps below to evaluate the surface polishing of titanium plates

Step 1: Immerse the sample in distilled water and let it stand for 2 minutes;

Step 2: Take the sample out of distilled water, rotate it 90°, and observe whether the water film is complete. If the water film is complete and does not break for a long time, it proves that the polishing is more successful. Record the integrity of the water film and the rupture of the water film at 1min, 5min, 10min, 20min and 30min. The results are shown in Table 2.

Table 2

Whether the water film is complete 1min 5min 10min 20min 30min Example 1 yes N N N N N Example 2 yes N N N N N Example 3 yes N N N N N Example 4 yes N N N N Y Example 5 yes N N N Y Example 6 yes N N N Y Example 7 yes N N Y Example 8 yes N N N N N Comparative example 1 yes N N N Y Comparative example 2 yes N N N Y Comparative example 3 yes N N N Y

Note: Among them, N means unbroken, and Y means cracked.

Test case 3

Evaluate the voltage required for anodizing titanium plates

With the titanium plate as the anode, the graphite as the cathode, and ₁₀ % _H2SO4 as the electrolyte, observe the voltage required to obtain the red plate. The results are shown in Table 3.

table 3

Voltage (V) Example 1 15 Example 2 15 Example 3 15 Example 4 16 Example 5 17 Example 6 17 Example 7 17 Example 8 14 Comparative example 1 19 Comparative example 2 18 Comparative example 3 19

As can be seen from the above Tables 1-3, the method of the present invention can solve the problem of water accumulation after shot blasting, while taking into account the roughness and gloss of the titanium plate surface, and preferably, in addition, using this method The titanium plate obtained by the inventive method requires a lower voltage to obtain the same color in the same solution concentration, which effectively saves the cost. And, because the method of the present invention can penetrate into the dead corner of the metal plate for polishing, it is especially suitable for the treatment of irregular parts.

As can be seen from Figures 1-3 of the present application, the technical solution of the present invention can effectively remove the oxide layer on the surface of the titanium metal plate. In the case of further preferred degreasing, the surface of the obtained titanium plate is more even and uniform, and the color brighter.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention. These simple modifications All belong to the protection scope of the present invention.

In addition, it should be noted that the various specific technical features described in the above specific implementation manners may be combined in any suitable manner if there is no contradiction. In order to avoid unnecessary repetition, various possible combinations are not further described in the present invention.

In addition, various combinations of different embodiments of the present invention can also be combined arbitrarily, as long as they do not violate the idea of the present invention, they should also be regarded as the disclosed content of the present invention.

Claims (8)

1. a kind of degreasing method of metal sheet surface, it is characterised in that this method is included in the sulfuric acid containing 5-15 weight % Electrochemical polishing treatment is carried out to the metal sheet surface in electrolyte；

Before the electrochemical polishing treatment, carrying out spray treatment to metallic plate using particle of the granularity less than or equal to 1mm makes The roughness for obtaining metal sheet surface is 1.5-0.8 μm, and relative to every square metre of metallic plate, the pressure of the injection is 1- 4MPa；The particle is made up of the particle of 3 kinds of granularities, and the granularities of big grain particles is 0.6-0.8mm, the granularity of middle grain particles For 0.2-0.5mm, the granularity of small size particle is 0.1-0.15mm；The big grain particles, middle grain particles and small grain size The ratio of grain is 1:3-6:0.5-1.2；The method of the spray treatment includes：The spray treatment of big grain particles is first carried out, then The spray treatment of the particle of granularity and small grain size in progress；

Wherein, the metallic plate is titanium plate and/or titanium alloy sheet.

2. according to the method for claim 1, wherein, the time of the electrochemical polishing treatment is 120-250s, and voltage is 1-10V, current density 0.35-0.65A/cm²。

3. according to the method for claim 2, wherein, the time of the electrochemical polishing treatment is 150-220s, and voltage is 3-8V, current density 0.45-0.55A/cm²。

4. according to the method described in any one in claim 1-3, wherein, in the electrochemical polishing treatment, the gold Category plate is negative electrode.

5. according to the method described in any one in claim 1-3, wherein, this method also includes in claim 1-3 to appoint The step of metallic plate after electrochemical polishing treatment described in meaning one is washed.

6. the method according to claim 11, wherein, it is described to wash the step of comprising at least 3 washings, wherein, for the first time For spray washing, second is soaking and water washing, is for the third time spray washing.

7. according to the method described in any one in claim 1-3, wherein, before the electrochemical polishing treatment, this method Also include soaking shown metal sheetmetal organic solvent.

8. according to the method for claim 7, wherein, the organic solvent is selected from gasoline, kerosene, toluene, trichloroethanes, four One or more in chloroethanes.