Nickel plating solution and preparation method of nickel plating stainless steel band based on nickel plating solution

Abstract

The embodiment of the invention provides a preparation method of a nickel-plated stainless steel band based on a nickel-plating solution, the nickel-plating solution used for the nickel-plated stainless steel band is included, the nickel-plating solution comprises nickel salt, boric acid, a leveling agent and deionized water, the nickel salt is composed of nickel sulfate or nickel aminosulfonate and nickel chloride, and the boric acid is composed of boric acid, a leveling agent and deionized water. The leveling agent is any one or any combination of hypophosphorous acid, phosphorous acid, oxalic acid and acetic acid, and the preparation process of the nickel-plated stainless steel band based on the nickel-plating solution can improve the surface quality of the nickel-plated stainless steel band and reduce the defects of scratches, pits and the like on the surface of the nickel-plated stainless steel band; and the corrosion resistance of the nickel-plated stainless steel band is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of metal surface treatment, in particular to a nickel plating solution and a method for preparing a nickel-plated stainless steel strip based on the nickel plating solution. Background Art

[0002] Nickel-plated stainless steel strips have been widely used in electronics, automobiles, construction, home appliances and other industries due to their good corrosion resistance, wear resistance, electrical conductivity, and weldability. With the further expansion of its application areas, the market has put forward higher requirements for nickel-plated stainless steel strips. Among them, the consistency and aesthetics of the product surface not only determine the corrosion resistance and wear resistance of the product, but also directly affect the sales and application of the product. Therefore, the preparation process of nickel-plated stainless steel strips should be optimized to effectively reduce surface defects such as scratches, indentations, and stripes. Summary of the invention

[0003] In view of this, the present invention provides a nickel plating solution and a method for preparing a nickel-plated stainless steel strip based on the nickel plating solution, which significantly optimizes the surface defects of the nickel-plated stainless steel strip, such as scratches, indentations, and stripes, and improves the aesthetics and application performance of the nickel-plated stainless steel strip.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] In a first aspect, an embodiment of the present invention provides a nickel plating solution with a leveling function, wherein the nickel plating solution with a leveling function comprises a nickel salt, boric acid, a leveling agent and deionized water, and the pH value is 1.0-2.5; wherein the leveling agent is any one of hypophosphorous acid, phosphorous acid, oxalic acid, and acetic acid or any combination thereof, and the concentration is 100-300 mg / L; the nickel salt is composed of nickel sulfate or nickel sulfamate and nickel chloride, and the concentration is 200-400 g / L; the concentration of the boric acid is 30-50 g / L;

[0006] In a second aspect, an embodiment of the present invention provides a method for preparing a nickel-plated stainless steel strip based on a nickel plating solution, the preparation method comprising:

[0007] (1) Using an alkaline degreasing liquid containing degreasing powder, the stainless steel strip is degreased and deoiled by chemical degreasing and electrolytic degreasing, the temperature is controlled at 50-70°C, the degreasing time is 3-6 minutes, and then hot water washing is performed;

[0008] (2) Using diluted sulfuric acid to activate the stainless steel strip, wherein the activation time is 1-5 min and the current density is 0.3-1 A / dm 2 , then wash with water;

[0009] (3) electroplating a pre-nickel layer on the surface of the stainless steel strip using a direct current power supply, wherein the plating solution used is prepared from 200-280 g / L of nickel chloride, 120-160 g / L of hydrochloric acid and deionized water, the temperature is controlled at 25-40° C., the pH value is 0.1-0.5, and then washing is performed to obtain a pre-nickel-plated stainless steel strip;

[0010] (4) electroplating a nickel layer on the surface of the pre-nickel-plated stainless steel strip in (3) using a direct current power supply, using the nickel plating solution with a leveling function as described in claim 1, controlling the temperature at 45-65° C. and the pH value at 1-5, then performing surface adjustment, and finally washing with water to obtain a nickel-plated stainless steel strip;

[0011] (5) electroplating a semi-bright nickel layer on the surface of the nickel-plated stainless steel strip in (4) using a direct current power supply, wherein the plating solution used is composed of 260-360 g / L of nickel sulfate, 10-20 g / L of nickel chloride, 30-50 g / L of boric acid, 10-30 ml / L of a semi-bright brightener and deionized water, and the temperature is controlled at 45-65° C. and the pH value is 2-5, and then washing is performed to obtain a semi-bright nickel-plated stainless steel strip;

[0012] (6) electroplating a full-bright nickel layer on the surface of the semi-bright nickel-plated stainless steel strip in (5) using a direct current power supply, wherein the plating solution used is composed of 260-360 g / L of nickel sulfate, 10-20 g / L of nickel chloride, 30-50 g / L of boric acid, 10-50 ml / L of full-bright brightener and deionized water, the temperature is controlled at 45-65° C., the pH value is 2-5, and then washing is performed to obtain a full-bright nickel-plated stainless steel strip;

[0013] (7) Drying, the drying temperature is 100-180°C.

[0014] The thickness of the pre-nickel plating layer is 0.1-0.5 μm, and the current density during electroplating is 1.5-3 A / dm 2 ;

[0015] The thickness of the dark nickel layer is 1-2 μm, and the current density during electroplating is 1.5-3 A / dm 2 ;

[0016] The surface of the dark nickel plating process was adjusted to change the current direction for electroplating for 10 seconds, and the current density was 5A / dm 2 ;

[0017] The thickness of the semi-bright nickel layer is 1-3 μm, and the current density during electroplating is 3-5 A / dm 2 ;

[0018] An embodiment of the present invention provides a method for preparing a nickel-plated stainless steel strip based on a nickel plating solution, which comprises a nickel plating solution for the nickel-plated stainless steel strip, wherein the nickel plating solution comprises a nickel salt, boric acid, a leveler and deionized water, wherein the nickel salt is composed of nickel sulfate or nickel sulfamate and nickel chloride, and the leveler is any one of hypophosphorous acid, phosphorous acid, oxalic acid and acetic acid or any combination thereof. The preparation process of the nickel-plated stainless steel strip based on the nickel plating solution can not only improve the surface quality of the nickel-plated stainless steel strip, reduce scratches, pits and other defects on the surface of the nickel-plated stainless steel strip, but also effectively improve the corrosion resistance of the nickel-plated stainless steel strip.

[0019] Compared with the prior art, the method for preparing a nickel-plated stainless steel strip based on a nickel plating solution provided by the present invention has the following beneficial effects:

[0020] Compared with the nickel-plated stainless steel strip prepared by conventional processes, the present invention uses phosphorous acid as a leveling agent in the nickel plating solution, which can cooperate with nickel electroplating to better reduce nickel ions in the solution to the surface of the plated piece and the defects on the surface, effectively improve the deep plating ability inside the surface defects of the stainless steel strip, and achieve a smoother plating effect; in addition, a reverse current is added during the nickel plating process to adjust the surface, which can remove the extra nickel deposited on the surface of the plated piece, balance the nickel thickness on the surface and in the defects, and is conducive to further improving the flatness of the surface of the plated piece; the present invention significantly optimizes the surface defects such as scribes, indentations, stripes, etc. on the surface of the nickel-plated stainless steel strip, improves the aesthetics and corrosion resistance of the nickel-plated stainless steel strip, and the plating solution components used in the preparation method provided by the present invention are simple and common, low cost, and simple to prepare. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flow chart of the preparation of the nickel-plated stainless steel strip;

[0022] Figure 2 The figures are the physical images of the embodiments and comparative examples of the present invention;

[0023] Figure 3 The microscope images of the embodiments and comparative examples of the present invention are shown in FIG. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0026] Before further describing the present invention in detail, the nouns and terms involved in the embodiments of the present invention are explained. The nouns and terms involved in the embodiments of the present invention are subject to the following explanations.

[0027] Example

[0028] This embodiment uses a 430 stainless steel strip with a thickness of 0.3 mm as the electroplating substrate, and takes the use of a nickel plating solution with a flattening function to prepare a nickel-plated stainless steel strip with a total nickel plating thickness greater than 2 μm as an example. The specific preparation steps are as follows:

[0029] (1) The stainless steel strip is degreased and deoiled by chemical degreasing and electrolytic degreasing using an alkaline degreasing liquid containing degreasing powder, the temperature is controlled at 70°C, the degreasing time is 5 minutes, and then hot water washing is performed; wherein the degreasing liquid formula is 50 g / L sodium hydroxide, 40 g / L sodium carbonate, 20 g / L trisodium phosphate, and 50 g / L degreasing powder; the water washing includes hot water brushing and ultrasonic cleaning.

[0030] (2) Using diluted sulfuric acid to activate the stainless steel strip, wherein a mixed solution of 4% dilute sulfuric acid and 2% hydrochloric acid is used, the activation temperature is 30° C., the activation time is 2 min, and the current density is 0.5 A / dm 2 , then wash with water after activation.

[0031] (3) A DC power supply is used to electroplate a pre-nickel layer on the surface of the stainless steel strip, with a current density of 1.5A / dm 2 The thickness of the pre-nickel plating layer is 0.3 μm, the temperature is controlled at 30°C, the pH value is 0.3, and then washed with water to obtain a pre-nickel-plated stainless steel strip; wherein the pre-plating solution is composed of 260 g / L nickel chloride, 130 g / L hydrochloric acid, and deionized water.

[0032] (4) A direct current power source is used to electroplate a nickel layer on the surface of the pre-nickel-plated stainless steel strip in (3) at a current density of 3A / dm 2 The thickness of the dark nickel layer was 1 μm, the temperature was controlled at 50 °C, the pH was 2, and then the surface was adjusted with a current density of 5 A / dm 2 The reverse current is used to continue electroplating for 10 seconds, and finally the nickel-plated stainless steel strip is washed with water; wherein the dark nickel plating solution is composed of 300g / L nickel sulfate, 40g / L boric acid, 200mg / L leveling agent, and deionized water.

[0033] (5) A direct current power source is used to electroplate a semi-bright nickel layer on the surface of the nickel-plated stainless steel strip in (4) at a current density of 5A / dm 2The thickness of the semi-bright nickel layer is 0.5 μm, the temperature is controlled at 60°C, the pH value is 3, and then washed with water to obtain a semi-bright nickel-plated stainless steel strip; wherein the semi-bright nickel plating solution is composed of 300 g / L nickel sulfate, 20 g / L nickel chloride, 35 g / L boric acid, 20 ml / L semi-bright brightener, and deionized water.

[0034] (6) A DC power supply is used to electroplate a semi-bright nickel layer on the surface of the nickel-plated stainless steel strip in (4) at a current density of 5A / dm 2 The thickness of the all-bright nickel layer is 0.5μm, the temperature is controlled at 60℃, the pH value is 3, and then washed with water to obtain a nickel-plated stainless steel strip with a total nickel plating layer thickness greater than 2μm; wherein the all-bright nickel plating solution is composed of 300g / L nickel sulfate, 20g / L nickel chloride, 35g / L boric acid, 20ml / L all-bright brightener, and deionized water.

[0035] (7) Drying: drying temperature: 140°C, 5 min.

[0036] Comparative Example 1

[0037] Compared with the embodiment, in this comparative example, no leveling agent is used in the nickel plating solution in step (4), that is, the nickel plating solution used is changed to 300 g / L nickel sulfate, 20 g / L nickel chloride, 35 g / L boric acid, and deionized water. At the same time, the surface adjustment step in step (4) is not performed, and the other steps and solutions are consistent with the embodiment.

[0038] Comparative Example 2

[0039] Compared with the embodiment, in this comparative example, no leveling agent is used in the nickel plating solution in step (4), that is, the nickel plating solution used is 300 g / L nickel sulfate, 40 g / L boric acid, and deionized water, and the other steps and solutions are consistent with the embodiment.

[0040] Comparative Example 3

[0041] Compared with the embodiment, the surface adjustment step in step (4) is not performed in this comparative example, and the other steps and solutions are consistent with the embodiment.

[0042] Comparative Example 4

[0043] Compared with the embodiment, the surface adjustment treatment time in step (4) was increased from 10 s to 30 s, and the other steps and solutions were consistent with the embodiment.

[0044] Please refer to Table 1 and Table 2, which are the comparison summaries of all embodiments and comparative examples in the present invention, from which it can be seen that:

[0045] 1) Compared with the comparative example 1 using the conventional nickel plating formula, the nickel-plated stainless steel strip prepared in the embodiment has a bright surface and no defects such as scratches and pits (see attached Figure 2 , 3In the comparison (in the middle), the surface roughness is smaller (0.04μm), indicating that the surface flatness of the plated nickel layer is better, that is, the defects on the original surface of the stainless steel strip are effectively improved by the nickel layer. And it also shows better corrosion resistance in the neutral salt spray test (reaching 24h 10 level), which once again verifies that the nickel layer on the surface of the nickel-plated stainless steel strip prepared in the embodiment has good integrity and no defects that cause corrosion; compared with the comparative example 2 without the use of the leveling agent, the nickel-plated stainless steel strip prepared in the embodiment also has better surface properties and corrosion resistance, indicating that the use of the leveling agent effectively improves the ability of the plating solution to nickel-plate in defects, because the leveling agent can be evenly dispersed into the defects on the surface of the plated part with the solution, and further in situ reduce nickel from the solution in the defects, forming a synergistic effect with the electroplated nickel, and finally achieving a better and smoother plating effect; therefore, the plating solution used in the nickel plating process in the present application is a nickel plating solution with a leveling function;

[0046] 2) The comparison of the results of the embodiment in Table 2 with those of comparative examples 3 and 4 shows that the surface adjustment operation performed during the nickel plating process also plays an important role in the flatness of the nickel plating layer, and the optimal parameter is 5A / dm 2 , 10s. This operation of surface adjustment by reverse current can modify the microstructure of the surface of the nickel plating layer to make it more uniform and smooth, but if the time is too long, it will affect the thickness and uniformity of the plating layer.

[0047]

[0048] Table 1

[0049]

[0050] Table 2

[0051] In summary, compared with the nickel-plated stainless steel strip prepared by the existing preparation process, the example of the present invention provides a method for preparing a nickel-plated stainless steel strip based on a nickel-plating solution with a flattening function, and the surface of the prepared nickel-plated stainless steel strip has no surface defects such as surface scratches, indentations, and stripes, and the aesthetics is significantly improved. In addition, the nickel-plating solution with a flattening function in the present invention contains a leveling agent that can improve the deep plating ability inside the surface defects of the stainless steel strip, making the nickel-plated layer flatter and having better corrosion resistance, and the plating solution components used are simple and common, with low cost and simple preparation.

[0052] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] In this document, the terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of elements other than those listed and may also include additional elements not expressly listed.

[0054] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A nickel plating solution, characterized in that The method comprises nickel salt, boric acid, a leveler and deionized water, with a pH value of 1.0-2.5; wherein the leveler is any one of hypophosphorous acid, phosphorous acid, oxalic acid and acetic acid or any combination thereof, with a concentration of 100-300 mg / L; the nickel salt is composed of nickel sulfate or nickel sulfamate and nickel chloride, with a concentration of 200-400 g / L; and the concentration of boric acid is 30-50 g / L.

2. A method for preparing a nickel-plated stainless steel strip based on a nickel plating solution, characterized in that: The preparation method comprises: (1) Using an alkaline degreasing liquid containing degreasing powder, the stainless steel strip is degreased and deoiled by chemical degreasing and electrolytic degreasing, the temperature is controlled at 50-70°C, the degreasing time is 3-6 minutes, and then hot water washing is performed; (2) Using diluted sulfuric acid to activate the stainless steel strip, wherein the activation time is 1-5 min and the current density is 0.3-1 A / dm 2 , then wash with water; (3) electroplating a pre-nickel layer on the surface of the stainless steel strip using a direct current power supply, wherein the plating solution used is prepared by 200-280 g / L of nickel chloride, 120-160 g / L of hydrochloric acid and deionized water, the temperature is controlled at 25-40° C., the pH value is 0.1-0.5, and then washing is performed to obtain a pre-nickel-plated stainless steel strip; (4) electroplating a nickel layer on the surface of the pre-nickel-plated stainless steel strip using a direct current power supply, wherein the nickel plating solution comprises a nickel salt, boric acid, a leveling agent and deionized water, and the pH value is 1.0-2.5; wherein the leveling agent is any one of hypophosphorous acid, phosphorous acid, oxalic acid, and acetic acid or any combination thereof, and the concentration is 100-300 mg / L; the nickel salt is composed of nickel sulfate or nickel sulfamate and nickel chloride, and the concentration is 200-400 g / L; the boric acid concentration is 30-50 g / L, the temperature is controlled to be 45-65° C., the pH value is 1-5, and then surface adjustment is performed, and finally water washing is performed to obtain the nickel-plated stainless steel strip; (5) electroplating a semi-bright nickel layer on the surface of the nickel-plated stainless steel strip using a direct current power supply, wherein the plating solution used is composed of 260-360 g / L of nickel sulfate, 10-20 g / L of nickel chloride, 30-50 g / L of boric acid, 10-30 ml / L of a semi-bright brightener and deionized water, the temperature is controlled to be 45-65° C., the pH value is 2-5, and then washing is performed to obtain a semi-bright nickel-plated stainless steel strip; (6) electroplating a full-bright nickel layer on the surface of the semi-bright nickel-plated stainless steel strip using a direct current power supply, wherein the plating solution used is composed of 260-360 g / L of nickel sulfate, 10-20 g / L of nickel chloride, 30-50 g / L of boric acid, 10-50 ml / L of a full-bright brightener and deionized water, the temperature is controlled to be 45-65° C., the pH value is 2-5, and then washing is performed to obtain a full-bright nickel-plated stainless steel strip; (7) Drying, the drying temperature is 100-180°C.

3. The method for preparing a nickel-plated stainless steel strip based on a nickel plating solution according to claim 2, characterized in that: The thickness of the pre-nickel plating layer is 0.1-0.5 μm, and the current density during electroplating is 1.5-3 A / dm 2 .

4. The method for preparing a nickel-plated stainless steel strip based on a nickel plating solution according to claim 2, characterized in that: The thickness of the nickel layer is 1-2 μm, and the current density during electroplating is 1.5-3 A / dm 2 .

5. The method for preparing a nickel-plated stainless steel strip based on a nickel plating solution according to claim 2, characterized in that: The surface of the nickel plating process is adjusted to change the current direction and perform electroplating for 10 seconds, and the current density is 3-5A / dm 2 .

6. The method for preparing a nickel-plated stainless steel strip based on a nickel plating solution according to claim 2, characterized in that: The thickness of the semi-bright nickel layer is 0.5-1 μm, and the current density during electroplating is 3-5 A / dm 2 .

7. The method for preparing a nickel-plated stainless steel strip based on a nickel plating solution according to claim 2, characterized in that: The thickness of the all-bright nickel layer is 0.5-1 μm, and the current density during electroplating is 3-5 A / dm 2 .

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