TWM641299U - Corrosion-resistant structure - Google Patents

Abstract

The corrosion-resistant structure of the present invention includes a base material and a nickel-phosphorus alloy coating, and the nickel-phosphorus alloy coating is arranged on the base material. Wherein, the surface roughness of the nickel-phosphorus alloy coating is less than 2 μm, the thickness of the nickel-phosphorus alloy coating is not less than 20 μm, and the Knoop hardness of the nickel-phosphorus alloy coating is HK 350-550. The corrosion-resistant structure can reduce the roughness of the inner wall structure of the steel cylinder and improve the corrosion resistance of the inner wall structure of the steel cylinder for a long time.

Description

corrosion resistant structure

The invention relates to a corrosion-resistant structure, in particular to a corrosion-resistant structure with a nickel-phosphorus alloy coating.

Steel cylinders are usually used to store special gases or liquids, so the inner wall structure of steel cylinders requires higher corrosion resistance. If the inner wall structure of steel cylinders is uneven, it is easy for corrosive gases or liquids to penetrate into the inner metal layer through the microscopic valleys on the surface , causing surface corrosion. Therefore, it is usually necessary to carry out anti-corrosion treatment on the inner wall of the steel cylinder to reduce the roughness of the inner wall structure of the steel cylinder. Among them, the current anti-corrosion treatment mainly has the following two methods:

1. Use the method of coating the surface of the inner wall with anti-rust primer, which can increase the corrosion resistance of the inner wall in a short time. However, in long-term use, the corrosion resistance of the inner wall structure will be greatly reduced due to continuous inflation and deflation that will cause the paint layer to fall off. In addition, the peeling paint layer may also block the pipes and valves.

2. Phosphating treatment, that is, immersing the steel cylinder in an acidic solution based on phosphoric acid and phosphate, so that a layer of insoluble phosphate film is formed on the surface of the inner wall structure of the steel cylinder, that is, the phosphating film. Although the corrosion resistance of the inner wall structure after phosphating treatment is improved, as time goes by, the inner wall structure will produce white phosphating powder, and the phosphating powder enters the pipeline with the gas and damages the control valve. Moreover, if the phosphating is repeated, the inner wall structure is prone to hydrogen embrittlement, which affects the safety of use.

Therefore, how to reduce the roughness of the inner wall structure of the steel cylinder and improve the corrosion resistance of the inner wall structure of the steel cylinder for a long time is worth considering by those skilled in the art.

The purpose of the present invention is to provide a corrosion-resistant structure, which can reduce the roughness of the inner wall structure of the steel cylinder and improve the corrosion resistance of the inner wall structure of the steel cylinder for a long time.

The corrosion-resistant structure of the present invention includes a base material and a nickel-phosphorus alloy coating, and the nickel-phosphorus alloy coating is arranged on the base material. Wherein, the surface roughness of the nickel-phosphorus alloy coating is less than 2 μm, and its thickness is not less than 20 μm.

In the corrosion-resistant structure mentioned above, an intermediate layer is also included between the substrate and the nickel-phosphorus alloy coating.

In the above-mentioned corrosion-resistant structure, the thickness of the intermediate layer is less than 1 μm.

In the above-mentioned corrosion-resistant structure, the Knoop hardness of the nickel-phosphorus alloy coating is HK 350-550.

In the above-mentioned corrosion-resistant structure, the nickel-phosphorus alloy coating includes 88wt% to 90wt% of nickel metal.

The object of the present invention is to provide a method for manufacturing a corrosion-resistant structure. The surface of the corrosion-resistant structure produced by the method for manufacturing the corrosion-resistant structure has relatively low roughness.

The manufacturing method of the corrosion-resistant structure of the present invention includes the following steps: firstly, a base material is provided. After that, a nickel-phosphorus alloy is deposited on the substrate to form a nickel-phosphorus alloy coating with a surface roughness less than 2 μm.

In the method of manufacturing the above-mentioned corrosion-resistant structure, the thickness of the nickel-phosphorus alloy plating layer is not less than 20 μm.

In the above-mentioned manufacturing method of the corrosion-resistant structure, it also includes forming an intermediate layer, and the intermediate layer is located between the base material and the nickel-phosphorus alloy plating layer.

In the above-mentioned manufacturing method of the corrosion-resistant structure, the nickel-phosphorus alloy is deposited on the substrate by electroless plating.

In the above-mentioned manufacturing method of the corrosion-resistant structure, the deposition rate of the nickel-phosphorus alloy is 0.08 μm/min˜0.28 μm/min.

In the above-mentioned manufacturing method of the corrosion-resistant structure, after the nickel-phosphorus alloy coating is formed, a heat treatment is performed on the nickel-phosphorus alloy coating, and the temperature of the heat treatment is 100°C-200°C.

In the above-mentioned manufacturing method of the corrosion-resistant structure, the pH value of the electroless plating solution used in the electroless plating method is 3-5.

In the above-mentioned manufacturing method of the corrosion-resistant structure, the temperature of the electroless plating solution is 80° C. to 95° C.

The new type has the following advantages: it can reduce the roughness of the inner wall of the steel cylinder and increase the corrosion resistance of the inner wall of the steel cylinder.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, preferred embodiments are specifically cited below, together with the accompanying drawings, for a detailed description as follows.

10, 20: Corrosion-resistant structure

12: Substrate

13: Nickel-phosphorus alloy coating

24: middle layer

S1~S2: steps

S21~S23: Steps

FIG. 1 is a cross-sectional view of a corrosion-resistant structure 10 of this embodiment and an enlarged view of a part of its structure.

FIG. 2 is a comparison chart of nickel-phosphorus alloy coating 13 with different thicknesses and the roughness of its surface.

FIG. 3 is a cross-sectional view of another embodiment of a corrosion-resistant structure 20 and an enlarged view of its partial structure.

FIG. 4 shows the manufacturing method of the corrosion-resistant structure 10 of this embodiment.

FIG. 5 shows a method for manufacturing the corrosion-resistant structure 20 according to another embodiment.

Please refer to FIG. 1 . FIG. 1 is a cross-sectional view of the corrosion-resistant structure 10 of this embodiment and an enlarged view of part of the structure. The corrosion-resistant structure 10 of the present invention is equivalent to the inner wall structure of a steel cylinder. The corrosion-resistant structure 10 includes a base material 12 and a nickel-phosphorus alloy coating 13. The material of the base material 12 is, for example, stainless steel or aluminum, and the nickel-phosphorus alloy coating 13 is set on the substrate 12 . Wherein, the Knoop hardness of the nickel-phosphorus alloy coating 13 is HK 350-550, and the nickel-phosphorus alloy coating 13 includes 88wt%-90wt% of nickel metal. In this way, the high material hardness and extremely high-purity nickel metal can improve the corrosion resistance of the inner wall structure of the steel cylinder for a long time.

Among the above, the so-called nickel-phosphorus alloy coating 13 is arranged on the base material 12, and is not limited to the nickel-phosphorus alloy coating 13 being directly deposited on the base material 12, and other components can be deposited between the nickel-phosphorus alloy coating 13 and the base material 12. film.

In addition, in this embodiment, the thickness of the nickel-phosphorus alloy coating 13 needs to be not less than 20 μm, that is, greater than or at least equal to 20 μm. The detailed reasons are as follows: first, please refer to FIG. The comparison chart of the surface roughness of the phosphorus alloy coating 13 and the nickel-phosphorus alloy coating 13. The applicant uses a number of nickel-phosphorus alloy coatings 13 of different thicknesses, The surface roughness of the nickel-phosphorus alloy coating 13 with various thicknesses was measured and compared, and the final result is shown in the comparison chart in FIG. 2 .

Can clearly know by the contrast graph of Fig. 2, when the thickness of nickel-phosphorus alloy coating 13 is 15 μ m, the roughness of its surface is 2.3 μ m, and when the thickness of nickel-phosphorus alloy coating 13 is 20 μ m, the roughness of its surface is 1.9 μm. Moreover, when the thickness of the nickel-phosphorus alloy coating 13 is greater, the surface of the nickel-phosphorus alloy coating 13 has a smaller roughness, for example, the surface roughness of the nickel-phosphorus alloy coating 13 with a thickness of 50 μm is 1.48 μm. Therefore, when the thickness of the nickel-phosphorus alloy coating 13 is not less than 20 μm, the surface roughness of the nickel-phosphorus alloy coating 13 will be less than 2 μm, which is already very smooth. In this way, the nickel-phosphorus alloy coating 13 is not easy for corrosive gas or liquid to penetrate into the base material 12 through the microscopic valleys on the surface, so as to prevent the surface of the corrosion-resistant structure 10 from being corroded.

Please refer to FIG. 3 . FIG. 3 is a cross-sectional view of another embodiment of a corrosion-resistant structure 20 and an enlarged view of a part of the structure. The difference between the corrosion-resistant structure 20 and the corrosion-resistant structure 10 is that the corrosion-resistant structure 20 also includes an intermediate layer 24, the intermediate layer 24 is arranged between the base material 12 and the nickel-phosphorus alloy coating 13, and the thickness of the intermediate layer 24 is less than 1 μm . In this embodiment, the material of the intermediate layer is, for example, palladium (Pd), and the intermediate layer helps the nickel-phosphorus alloy coating 13 to provide a good conductive layer and adhesion, and prevents the nickel-phosphorus alloy coating 13 from corrosion and peeling off.

In addition, when nickel-phosphorus alloy is deposited, because of its microstructure is different from that of the substrate 12, the film formed by deposition will produce a compressive stress or tensile hardness. When the film is deposited thicker, the stress is also greater, and excessive hardness The force will cause the film and substrate 12 to come off. Therefore, the thickness of the nickel-phosphorus alloy coating 13 is preferably not greater than 50 μm.

The above content mainly discloses the structures of the corrosion-resistant structure 10 and the corrosion-resistant structure 20 . The following will illustrate how to manufacture the corrosion-resistant structure 10 and the corrosion-resistant structure 20 with reference to FIG. 4 and FIG. 5 respectively.

First, please refer to step S1 , providing a base material 12 , such as stainless steel or aluminum.

Afterwards, referring to step S2 , a nickel-phosphorus alloy is deposited on the substrate 12 to form a nickel-phosphorus alloy coating 13 with a surface roughness less than 2 μm. Specifically, the nickel-phosphorus alloy is deposited on the base material 12 by means of electroless plating, the pH value of the electroless plating solution used in the electroless nickel plating method is 3-5, and the temperature of the electroless plating solution 80° C. to 95° C., so that the deposition rate of the nickel-phosphorus alloy is 0.08 μm/min to 0.28 μm/min. In this way, a nickel-phosphorous alloy plating layer 13 with a uniform thickness can be formed.

Among the above, the process involved in the electroless plating method, for example: pretreatment → degreasing → water washing → pickling (sulfuric acid or sodium sulfate solution) → water washing → microetching → water washing → pre-soaking (H2SO4) → activation (Pd contact media)→water washing→chemical nickel (Ni/P)→water washing→drying, which are familiar to those with ordinary knowledge in the field, so they will not be described in detail in this specification.

In addition, after the step S2, a heat treatment is usually performed on the nickel-phosphorus alloy coating 13, and the temperature of the heat treatment is 100°C-200°C. This is because the thin film deposited by electroless plating is less dense and tends to contain water vapor in the micropores. The heat treatment can dissipate the water vapor, which helps to increase the compactness and hardness of the nickel-phosphorus alloy coating 13 .

The method for manufacturing the corrosion-resistant structure 20 according to another embodiment of the present invention includes the following steps: First, please refer to step S21 , providing a base material 12 . Afterwards, please refer to step S22 , deposit a palladium metal on the substrate 12 to form an intermediate layer 24 with a thickness less than 1 μm, and the material of the intermediate layer is, for example, palladium (Pd). Afterwards, referring to step S23 , a nickel-phosphorus alloy is deposited on the intermediate layer 24 to form a nickel-phosphorus alloy coating 13 with a surface roughness less than 2 μm. In this way, the corrosion-resistant structure 20 of this embodiment is completed.

To sum up, the new corrosion-resistant structure effectively reduces the roughness of the inner wall structure of the steel cylinder, and improves the corrosion resistance of the inner wall structure of the steel cylinder for a long time.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field may make some changes and modifications without departing from the spirit and scope of the present invention. , so the scope of protection of the present invention should be defined by the scope of the appended patent application.

10: Corrosion-resistant structure

12: Substrate

13: Nickel-phosphorus alloy coating

Claims (6)

A corrosion-resistant structure, comprising: a base material; and a nickel-phosphorus alloy coating disposed on the base material; wherein, the surface roughness of the nickel-phosphorus alloy coating is less than 2 μm. The corrosion-resistant structure as claimed in claim 1, wherein the thickness of the nickel-phosphorus alloy coating is not less than 20 μm. The corrosion-resistant structure as claimed in claim 1, further comprising an intermediate layer between the substrate and the nickel-phosphorus alloy coating. The corrosion-resistant structure as claimed in claim 3, wherein the thickness of the intermediate layer is less than 1 μm. The corrosion-resistant structure according to claim 1 or claim 2, wherein the Knoop hardness of the nickel-phosphorus alloy coating is HK 350-550. The corrosion-resistant structure according to claim 1 or claim 2, wherein the nickel-phosphorus alloy coating includes 88wt% to 90wt% nickel metal.

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