A steel surface composite coating processing method and coating

Abstract

The present invention relates to the technical field of surface corrosion protection, and specifically discloses a steel surface composite coating processing method and coating, comprising a steel substrate and an innermost coating, an intermediate coating and an outer coating sequentially loaded on the surface of the steel substrate, wherein the processing method comprises laser processing the steel substrate to form the innermost coating, and adopting a hot dip coating method to prepare the intermediate coating and the outer coating. The composite coating of the present invention has good bonding strength with the steel substrate and strong corrosion resistance.

Description

Technical Field

[0001] The invention relates to the technical field of surface anticorrosion, and in particular to a steel surface composite coating processing method and coating. Background Art

[0002] Steel is a structural material that can be seen everywhere in life. In humid and corrosive environments, it is often affected by local corrosion. In order to improve the corrosion resistance of steel, hot-dip galvanizing, spray coating, electroplating coating and other technologies are often used to set coatings on the steel surface. However, traditional coatings have problems such as uneven coating quality, poor adhesion, and poor local corrosion resistance. Summary of the invention

[0003] The purpose of the present invention is to provide a steel surface composite coating processing method and coating to solve the problems of poor adhesion, uneven quality and poor local corrosion resistance of existing coatings.

[0004] In order to solve the above technical problems, the present invention provides a method for processing a composite coating on a steel surface, comprising the following steps:

[0005] S1. Performing laser treatment on the surface of the steel substrate to form an innermost phase change layer coating on the surface of the steel substrate, and performing activation treatment on the surface of the innermost phase change layer coating to remove the oxide layer, thereby obtaining a steel substrate with the innermost layer coating loaded on the surface;

[0006] S2, selecting a steel material with the same composition as the steel substrate as the first steel material to be smelted and placing it into a vacuum melting device, and adding a certain amount of manganese, aluminum and copper to melt together to obtain a molten first metal liquid, immersing the steel substrate with the innermost coating on the surface into the molten first metal liquid, and treating it by hot dipping, after which an intermediate coating is formed on the surface of the innermost coating;

[0007] S3. Select steel with the same composition as the steel substrate as the first steel to be smelted, put it into the vacuum melting equipment, add a certain amount of manganese and copper to melt together, and obtain a molten second metal liquid. Immerse the steel substrate with the innermost coating and the middle coating on the surface into the molten second metal liquid, and use hot dip plating to treat it. After the treatment is completed, an outer coating is formed on the surface of the middle coating.

[0008] Preferably, in step S2, the mass fractions of manganese, aluminum and copper in the first metal liquid are 0.15%, 0.08% and 0.02% respectively, and in step S3, the mass fractions of manganese and copper in the second metal liquid are 0.22% and 0.03% respectively.

[0009] Preferably, in step S1, the laser treatment is laser quenching, the laser power is 1200-2000w, and the scanning speed is 400-800mm / min.

[0010] Preferably, in step S1, the innermost phase change layer coating thickness is 2-500 nm.

[0011] Preferably, in step S1, the ratio of the activated metal surface after the activation treatment to the total surface area is greater than 99.97%.

[0012] Preferably, in steps S2 and S3, the vacuum degree of the vacuum melting equipment is set to 0.001-10 Pa, the temperature is set to 1500-2000° C., the insulation time is set to 15-40 min, and the melting rate is set to 1.5-6 kg / min.

[0013] Preferably, in steps S2 and S3, the hot dip treatment is carried out at a temperature of 1200-1500° C. and for a time of 30 s-2 min.

[0014] Preferably, the thickness ratio of the innermost coating layer, the middle coating layer and the outer coating layer is 3:13:5, and the sum of the thicknesses is 0.1-3 mm.

[0015] A coating is prepared according to the above-mentioned steel surface composite coating processing method.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention performs laser processing on the substrate to improve the hardness, wear resistance, strength and corrosion resistance of the steel. Manganese, aluminum and copper are added during the preparation of the middle layer, and manganese and copper are added during the preparation of the outer layer, which can improve the hardness, strength, wear resistance, heat resistance, corrosion resistance and other properties of the steel. A thicker coating is obtained by hot-dip plating, which improves the corrosion resistance of the steel and improves the coating quality. The addition of metal elements during vacuum melting can improve the corrosion resistance of the steel, especially in a humid and corrosive environment, so that the steel has better corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a flow chart of a processing method according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of a multi-layer composite structure local corrosion resistant steel surface coating according to an embodiment of the present invention.

[0020] In the figure, 1. Steel substrate; 2. Innermost coating; 3. Middle coating; 4. Outer coating. DETAILED DESCRIPTION

[0021] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0022] Example 1

[0023] This embodiment provides a method for processing a composite coating on a steel surface. Figure 1 As shown, the following steps are included:

[0024] S1. The surface of the steel substrate 1 is subjected to laser quenching treatment, the laser power is 1200w, the scanning speed is 400mm / min, the innermost phase change layer coating is formed on the surface of the steel substrate 1, the thickness of the innermost phase change layer coating is 2nm, the surface of the innermost phase change layer coating is subjected to activation treatment, the activated metal surface after the activation treatment accounts for more than 99.97% of the total surface area, the oxide layer is removed, and the steel substrate 1 with the innermost coating 2 loaded on the surface is obtained;

[0025] S2. Select a steel material with the same composition as the steel substrate 1 as the first steel material to be smelted and put it into a vacuum melting device, and add a certain amount of manganese, aluminum and copper for co-smelting. The vacuum degree, temperature and holding time of the vacuum melting device are set to 0.001pa, 1500°C, 15min and 1.5kg / min respectively to obtain a molten first metal liquid. The mass fractions of manganese, aluminum and copper in the first metal liquid are 0.15%, 0.08% and 0.02% respectively. Immerse the steel substrate 1 with the innermost coating 2 on the surface into the molten first metal liquid and treat it by hot dip plating. The temperature is set to 1200°C for 30s. After the hot dip plating, an intermediate coating 3 is formed on the surface of the innermost coating 2.

[0026] S3. Select steel with the same composition as the steel substrate 1 as the first steel to be smelted and put it into the vacuum melting equipment, and add a certain amount of manganese and copper for co-smelting. The vacuum degree, temperature and holding time of the vacuum melting equipment are set to 0.001pa, 1500℃, 15min and 1.5kg / min, respectively. A molten second metal liquid is obtained. The mass fractions of manganese and copper in the second metal liquid are 0.22% and 0.03%, respectively. The steel substrate 1 with the innermost coating 2 and the middle coating 3 on the surface is immersed in the molten second metal liquid and treated by hot dip plating. The temperature set during hot dip plating is 1200℃ and the time is 30s. After hot dip plating, an outer coating 4 is formed on the surface of the middle coating 3.

[0027] The thickness ratio of the innermost coating 2, the middle coating 3 and the outer coating 4 is 3:13:5, and the total thickness is 0.1 mm.

[0028] This embodiment provides a coating, which is prepared according to the above-mentioned steel surface composite coating processing method.

[0029] Example 2

[0030] This embodiment provides a method for processing a composite coating on a steel surface. Figure 1 As shown, the following steps are included:

[0031] S1. The surface of the steel substrate 1 is subjected to laser quenching treatment, the laser power is 1600w, the scanning speed is 600mm / min, the innermost phase change layer coating is formed on the surface of the steel substrate 1, the thickness of the innermost phase change layer coating is 251nm, the surface of the innermost phase change layer coating is subjected to activation treatment, the activated metal surface after the activation treatment accounts for more than 99.97% of the total surface area, the oxide layer is removed, and the steel substrate 1 with the innermost coating 2 loaded on the surface is obtained;

[0032] S2. Select a steel material with the same composition as the steel substrate 1 as the first steel material to be smelted and put it into a vacuum melting device, and add a certain amount of manganese, aluminum and copper for co-smelting. The vacuum degree, temperature and holding time of the vacuum melting device are set to 5 Pa, 1750 ° C, 28 min and 3.8 kg / min respectively. A molten first metal liquid is obtained. The mass fractions of manganese, aluminum and copper in the first metal liquid are 0.15%, 0.08% and 0.02% respectively. Immerse the steel substrate 1 with the innermost coating 2 on the surface into the molten first metal liquid and treat it by hot dip plating. The temperature set during hot dip plating is 1350 ° C and the time is 75 s. After hot dip plating, an intermediate coating 3 is formed on the surface of the innermost coating 2.

[0033] S3. Select steel with the same composition as the steel substrate 1 as the first steel to be smelted and put it into the vacuum melting equipment, and add a certain amount of manganese and copper for co-smelting. The vacuum degree, temperature and holding time of the vacuum melting equipment are set to 5 Pa, 1750 ° C, 28 min and 3.8 kg / min, respectively. A molten second metal liquid is obtained. The mass fractions of manganese and copper in the second metal liquid are 0.22% and 0.03%, respectively. The steel substrate 1 with the innermost coating 2 and the middle coating 3 on the surface is immersed in the molten second metal liquid and treated by hot dip plating. The temperature set during hot dip plating is 1350 ° C and the time is 75 s. After hot dip plating, an outer coating 4 is formed on the surface of the middle coating 3.

[0034] The thickness ratio of the innermost coating 2, the middle coating 3 and the outer coating 4 is 3:13:5, and the total thickness is 1.5 mm.

[0035] This embodiment provides a coating, which is prepared according to the above-mentioned steel surface composite coating processing method.

[0036] Example 3

[0037] This embodiment provides a method for processing a composite coating on a steel surface. Figure 1 As shown, the following steps are included:

[0038] S1. The surface of the steel substrate 1 is subjected to laser quenching treatment, the laser power is 2000w, the scanning speed is 800mm / min, the innermost phase change layer coating is formed on the surface of the steel substrate 1, the thickness of the innermost phase change layer coating is 500nm, the surface of the innermost phase change layer coating is subjected to activation treatment, the activated metal surface after the activation treatment accounts for more than 99.97% of the total surface area, the oxide layer is removed, and the steel substrate 1 with the innermost coating 2 loaded on the surface is obtained;

[0039] S2. Select a steel material with the same composition as the steel substrate 1 as the first steel material to be smelted and put it into a vacuum melting device, and add a certain amount of manganese, aluminum and copper to melt together. The vacuum degree, temperature and holding time of the vacuum melting device are set to 10 Pa, 2000 ° C, 40 min and 6 kg / min respectively during operation to obtain a molten first metal liquid. The mass fractions of manganese, aluminum and copper in the first metal liquid are 0.15%, 0.08% and 0.02% respectively. Immerse the steel substrate 1 with the innermost coating 2 on the surface into the molten first metal liquid and treat it by hot dip plating. The temperature set during hot dip plating is 1500 ° C and the time is 2 min. After hot dip plating, an intermediate coating 3 is formed on the surface of the innermost coating 2.

[0040] S3. Select steel with the same composition as the steel substrate 1 as the first steel to be smelted and put it into the vacuum melting equipment, and add a certain amount of manganese and copper for smelting together. The vacuum degree, temperature and holding time of the vacuum melting equipment are set to 10 Pa, 2000 ° C, 40 min and 6 kg / min, respectively. The mass fractions of manganese and copper in the second metal liquid are 0.22% and 0.03%, respectively. Immerse the steel substrate 1 with the innermost coating 2 and the middle coating 3 on the surface into the molten second metal liquid and treat it by hot dip plating. The temperature set during hot dip plating is 1500 ° C and the time is 2 min. After hot dip plating, the outer coating 4 is formed on the surface of the middle coating 3.

[0041] The thickness ratio of the innermost coating 2, the middle coating 3 and the outer coating 4 is 3:13:5, and the total thickness is 3 mm.

[0042] This embodiment provides a coating, which is prepared according to the above-mentioned steel surface composite coating processing method.

[0043] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A method for processing a composite coating on a steel surface, characterized in that: The following steps are involved: S1, performing laser treatment on the surface of the steel substrate (1) to form an innermost phase change layer coating on the surface of the steel substrate (1), performing activation treatment on the surface of the innermost phase change layer coating to remove the oxide layer, and obtaining a steel substrate (1) with the innermost layer coating (2) loaded on the surface; S2, selecting a steel material with the same composition as the steel substrate (1) as the first steel material to be smelted and placing it into a vacuum melting device, and adding a certain amount of manganese, aluminum and copper to melt together to obtain a molten first metal liquid, immersing the steel substrate (1) with the innermost coating (2) on the surface into the molten first metal liquid, and treating it by hot dipping, and after the treatment, an intermediate coating (3) is formed on the surface of the innermost coating (2); S3. Select steel with the same composition as the steel substrate (1) as the first steel to be smelted, put it into a vacuum melting device, add a certain amount of manganese and copper and smelt them together to obtain a molten second metal liquid, immerse the steel substrate (1) with the innermost coating (2) and the middle coating (3) on the surface into the molten second metal liquid, and treat it by hot dip plating. After the treatment, an outer coating (4) is formed on the surface of the middle coating (3).

2. The method for processing composite coating on steel surface according to claim 1, characterized in that: In step S2, the mass fractions of manganese, aluminum and copper in the first metal liquid are 0.15%, 0.08% and 0.02% respectively. In step S3, the mass fractions of manganese and copper in the second metal liquid are 0.22% and 0.03% respectively.

3. The method for processing composite coating on steel surface according to claim 1, characterized in that: In the step S1, the laser treatment is laser quenching, the laser power is 1200-2000w, and the scanning speed is 400-800mm / min.

4. The method for processing composite coating on steel surface according to claim 1, characterized in that: In the step S1, the thickness of the innermost phase change layer coating is 2-500 nm.

5. The method for processing composite coating on steel surface according to claim 1, characterized in that: In the step S1, the activated metal surface after the activation treatment accounts for more than 99.97% of the total surface area.

6. The method for processing composite coating on steel surface according to claim 1, characterized in that: In the steps S2 and S3, the vacuum degree, temperature, holding time and melting rate of the vacuum melting equipment are set to 0.001-10 Pa, 1500-2000° C., 15-40 min and 1.5-6 kg / min, respectively.

7. The method for processing composite coating on steel surface according to claim 1, characterized in that: In the steps S2 and S3, the temperature during the hot dip treatment is 1200-1500° C. and the time is 30 seconds to 2 minutes.

8. The method for processing composite coating on a material surface according to claim 1, characterized in that: The thickness ratio of the innermost coating layer (2), the middle coating layer (3) and the outer coating layer (4) is 3:13:5, and the sum of their thicknesses is 0.1-3 mm.

9. A coating, characterized in that: The coating is prepared according to the steel surface composite coating processing method according to any one of claims 1 to 8.

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