Nickel-plated stainless steel and preparation process thereof

Abstract

The invention relates to the technical field of nickel-plated stainless steel, in particular to nickel-plated stainless steel and a preparation process thereof.The nickel-plated stainless steel at least comprises a stainless steel base material, an impact nickel plating layer, a dark nickel plating layer and a bright nickel plating layer from bottom to top. The binding force of the plating layer and the stainless steel base material is remarkably improved, meanwhile, the internal stress of the plating layer is reduced, the phenomena of blackening, bubbling, falling and the like of the plating layer are avoided, the quality of the nickel-plated stainless steel product is guaranteed, the obtained nickel-plated stainless steel product is uniform in plating layer, high in binding strength and excellent in corrosion resistance, the preparation process is simple, the production efficiency is high, and the cost is relatively low. And large-scale industrial production, popularization and application are easy to realize.

Description

Technical Field

[0001] The invention relates to the technical field of stainless steel nickel-plated steel materials, in particular to a stainless steel nickel-plated steel material and a preparation process thereof. Background Art

[0002] In the field of new energy, especially in the lithium-ion battery industry, nickel-plated steel strips are widely used in the manufacture of lithium battery shells. However, in the preparation process of existing nickel-plated steel strips, there is a common problem of poor bonding between the coating and the substrate, which increases the complexity of the nickel plating process. At present, some studies hope to replace nickel-plated steel strips for battery shells by preparing graphene-plated steel strips. For example, a Chinese patent (publication number CN118639289A) discloses steel strips for new energy battery steel shells and their preparation methods. However, the cost is relatively high, and the process flow is not significantly shortened, which cannot meet the requirements of large-scale industrial applications. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a stainless steel nickel-plated steel material and a preparation process thereof. The obtained stainless steel nickel-plated steel material has a uniform coating, high bonding strength, and excellent corrosion resistance. The preparation process is simple, the production efficiency is high, the cost is relatively low, and it is easy to realize large-scale industrial production and popularize and apply.

[0004] On one hand, the present invention provides a stainless steel nickel-plated steel material, which comprises at least: a stainless steel substrate, an impact nickel plating layer, a dark nickel plating layer, and a bright nickel plating layer from bottom to top.

[0005] As a preferred technical solution, the thickness of the impact nickel plating layer is 0.1-0.5 μm, preferably 0.2-0.3 μm, and most preferably 0.2 μm.

[0006] As a preferred technical solution, the grain size of the impact nickel plating layer is 70-100nm.

[0007] As a preferred technical solution, the thickness of the dark nickel plating layer is 0.1-5 μm, preferably 0.5-2.8 μm, and most preferably 1-1.5 μm.

[0008] As a preferred technical solution, the thickness of the bright nickel plating layer is 0.1-5 μm, preferably 0.5-3 μm, and most preferably 1-2 μm.

[0009] Another aspect of the present invention provides a process for preparing a stainless steel nickel-plated steel material, comprising at least the following steps:

[0010] (1) performing surface pretreatment on a stainless steel substrate before plating to obtain a stainless steel substrate to be plated;

[0011] (2) washing the stainless steel substrate to be plated with water and then electroplating the substrate to be plated to form an impact nickel coating on the surface of the stainless steel substrate;

[0012] (3) after washing, secondary electrodeposition is performed to form a dark nickel coating on the surface of the impact nickel coating;

[0013] (4) after washing, three times of electrodeposition are performed on the dark nickel coating to form a bright nickel coating;

[0014] (5) After washing, drying and rolling, the product is obtained.

[0015] As a preferred technical solution, the surface pretreatment before plating in step (1) at least includes electrochemical degreasing, cleaning, electrolytic pickling activation, and hydrochloric acid activation.

[0016] Preferably, the electrochemical degreasing comprises at least the following steps: placing the stainless steel substrate in a degreasing liquid at a temperature of 50-70°C and a current density of 4-6A / dm 2 Electrochemical degreasing is carried out under the conditions of .

[0017] Preferably, the degreasing liquid at least comprises: NaOH 20-40 g / L, Na2CO3 20-40 g / L, Na3PO4 20-40 g / L, and the solvent is water.

[0018] Preferably, the cleaning is rinsing with distilled water.

[0019] Preferably, the electrolytic pickling activation comprises at least the following steps: placing the cleaned stainless steel substrate in a 220-260 mL / L H2SO4 aqueous solution, controlling the current flow density to 4-6 A / dm 2 , electrolytic pickling activation is carried out at 15-30℃.

[0020] Preferably, the hydrochloric acid activation comprises at least the following steps: placing the stainless steel substrate activated by electrolytic pickling into 80-100 mL / L HCl aqueous solution, and performing hydrochloric acid activation at 20-35° C. to obtain the stainless steel substrate to be plated.

[0021] The stainless steel nickel-plated steel material provided by the present invention is helpful for the subsequent bonding of the impact nickel plating layer with the stainless steel substrate and improves the uniformity of the impact nickel plating layer by performing pre-plating surface pretreatment including electrochemical degreasing, cleaning, electrolytic pickling activation and hydrochloric acid activation on the stainless steel substrate.

[0022] As a preferred technical solution, the electrolyte solution for electrodeposition in step (2) at least includes: HCl 80-100 mL / L, NiCl2·6H2O 200-220 g / L, and the solvent is water.

[0023] As a preferred technical solution, the anode for electrodeposition in step (2) is a nickel block with a purity of ≥99.8%.

[0024] As a preferred technical solution, the temperature of the electrodeposition in step (2) is 35-50°C.

[0025] As a preferred technical solution, the electrolyte solution for secondary electrodeposition in step (3) at least includes: NiSO4·6H2O 260-300 g / L, NiCl2·6H2O 35-45 g / L, H3BO3 35-45 g / L, and the solvent is water.

[0026] Preferably, the pH of the electrolyte solution for the secondary electrodeposition is 3.6-4.2.

[0027] As a preferred technical solution, the anode for the secondary electrodeposition in step (3) is a nickel plate.

[0028] As a preferred technical solution, the temperature of the secondary electrodeposition in step (3) is 40-70°C.

[0029] As a preferred technical solution, the electrolyte solution for the three electrodepositions in step (4) at least includes: NiSO4·6H2O 280-320 g / L, NiCl2·6H2O 35-45 g / L, H3BO3 35-45 g / L, and the solvent is water.

[0030] Preferably, the pH of the electrolyte solution for the three electrodepositions is 3.6-4.2.

[0031] As a preferred technical solution, the anode for the three electrodepositions in step (4) is a nickel plate.

[0032] As a preferred technical solution, the temperature of the three electrodepositions in step (4) is 40-70°C.

[0033] The present invention deposits impact nickel plating, dark nickel plating, and bright nickel plating on the surface of a stainless steel substrate in sequence, thereby significantly improving the bonding strength between the plating and the stainless steel substrate, while reducing the internal stress of the plating, avoiding blackening, blistering, and shedding of the plating, and ensuring the quality of the stainless steel nickel-plated steel product. Furthermore, the stainless steel nickel-plated steel provided by the present invention has particularly good corrosion resistance, and can maintain stable performance, especially in extreme environments (such as high temperature or humid environments), and can be used for primary batteries, secondary batteries, and plasma power battery shell materials.

[0034] In addition, the stainless steel nickel-plated steel provided by the present invention has good surface finish and aesthetics, and can also achieve strong, ductile and firm welding, better meeting the actual application requirements of new energy battery shells.

[0035] Beneficial Effects

[0036] 1. The present invention provides a stainless steel nickel-plated steel material and a preparation process thereof. The obtained stainless steel nickel-plated steel material has a uniform coating, high bonding strength, and excellent corrosion resistance. The preparation process is simple, the production efficiency is high, and the cost is relatively low, and it is easy to realize large-scale industrial production and popularize and apply.

[0037] 2. The stainless steel nickel-plated steel provided by the present invention facilitates the subsequent bonding of the impact nickel plating layer with the stainless steel substrate and improves the uniformity of the impact nickel plating layer by performing pre-plating surface pretreatment of the stainless steel substrate including electrochemical degreasing, cleaning, electrolytic pickling activation, and hydrochloric acid activation.

[0038] 3. The present invention deposits impact nickel plating, dark nickel plating and bright nickel plating on the surface of stainless steel substrate in sequence, thereby significantly improving the bonding strength between the plating and the stainless steel substrate, and reducing the internal stress of the plating, avoiding blackening, blistering and shedding of the plating, and ensuring the quality of stainless steel nickel-plated steel products.

[0039] 4. The stainless steel nickel-plated steel provided by the present invention has special corrosion resistance, especially in extreme environments (such as high temperature or humid environments), and can maintain stable performance, and can be used for primary batteries, secondary batteries and plasma power battery shell materials.

[0040] 5. The stainless steel nickel-plated steel provided by the present invention has good surface finish and aesthetics, and can also achieve strong, ductile and firm welding, better meeting the practical application requirements of new energy battery shells. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The bending test results of the stainless steel nickel-plated steel provided in Example 1, the left side of the figure is before the bending test, and the right side is after the bending test.

[0042] Figure 2 The bending test results of the stainless steel nickel-plated steel provided in Example 2, the left side of the figure is before the bending test, and the right side is after the bending test.

[0043] Figure 3 The bending test results of the stainless steel nickel-plated steel provided for Comparative Example 1.

[0044] Figure 4 The bending test results of the stainless steel nickel-plated steel provided for comparative example 2, the left side of the figure is before the bending test, and the right side is after the bending test. DETAILED DESCRIPTION

[0045] Example 1

[0046] Embodiment 1 of the present invention provides a stainless steel nickel-plated steel material, which includes a stainless steel substrate, an impact nickel plating layer, a dark nickel plating layer, and a bright nickel plating layer from bottom to top.

[0047] The thickness of the strike nickel plating layer is 0.2 μm.

[0048] The grain size of the impact nickel plating layer is 70-100nm.

[0049] The thickness of the dark nickel plating layer is 1.3 μm.

[0050] The thickness of the bright nickel plating layer is 1.5 μm.

[0051] Embodiment 1 of the present invention provides a process for preparing a stainless steel nickel-plated steel material, comprising the following steps:

[0052] (1) performing surface pretreatment on a stainless steel substrate before plating to obtain a stainless steel substrate to be plated;

[0053] (2) washing the stainless steel substrate to be plated with water and then electroplating the substrate to be plated to form an impact nickel coating on the surface of the stainless steel substrate;

[0054] (3) after washing, secondary electrodeposition is performed to form a dark nickel coating on the surface of the impact nickel coating;

[0055] (4) after washing, three times of electrodeposition are performed on the dark nickel coating to form a bright nickel coating;

[0056] (5) After washing, drying and rolling, the product is obtained.

[0057] The surface pretreatment before plating in step (1) includes electrochemical degreasing, cleaning, electrolytic pickling activation, and hydrochloric acid activation.

[0058] The electrochemical degreasing comprises the following steps: placing the stainless steel substrate in a degreasing liquid at a temperature of 60° C. and a current density of 5A / dm 2 Electrochemical degreasing is carried out under the conditions of .

[0059] The degreasing liquid includes: NaOH 30g / L, Na2CO3 30g / L, Na3PO4 30g / L, and the solvent is water.

[0060] The cleaning is rinsing with distilled water.

[0061] The electrolytic pickling activation comprises the following steps: placing the cleaned stainless steel substrate into a 240 mL / L H2SO4 aqueous solution, and controlling the current flow density to 5 A / dm 2 , electrolytic pickling activation was carried out at 25°C.

[0062] The hydrochloric acid activation comprises the following steps: placing the stainless steel substrate activated by electrolytic pickling into a 90 mL / L HCl aqueous solution, and performing hydrochloric acid activation at 28° C. to obtain the stainless steel substrate to be plated.

[0063] The electrolyte solution for electrodeposition in step (2) includes: 90 mL / L HCl, 210 g / L NiCl2·6H2O, and the solvent is water.

[0064] The anode for electrodeposition in step (2) is a nickel block with a purity of ≥99.8%.

[0065] The temperature of the electrodeposition in the step (2) is 40°C.

[0066] The electrolyte solution for the secondary electrodeposition in step (3) includes: NiSO4·6H2O 280 g / L, NiCl2·6H2O 40 g / L, H3BO3 40 g / L, and the solvent is water.

[0067] The pH of the electrolyte solution for the secondary electrodeposition is 4.

[0068] The anode for the secondary electrodeposition in step (3) is a nickel plate.

[0069] The temperature of the secondary electrodeposition in step (3) is 55°C.

[0070] The electrolyte solution for the three electrodepositions in step (4) includes: 300 g / L NiSO4·6H2O, 40 g / L NiCl2·6H2O, 40 g / L H3BO3, and the solvent is water.

[0071] The pH of the electrolyte solution for the three electrodepositions was 4.

[0072] The anode for the three electrodepositions in step (4) is a nickel plate.

[0073] The temperature of the three electrodepositions in step (4) is 55°C.

[0074] Example 2

[0075] Embodiment 2 of the present invention provides a stainless steel nickel-plated steel material and a preparation process thereof, and its specific implementation manner is the same as that of Embodiment 1, except that the thickness of the dark nickel plating layer is 2.8 μm, and the thickness of the bright nickel plating layer is 3 μm.

[0076] Comparative Example 1

[0077] Comparative Example 1 of the present invention provides a stainless steel nickel-plated steel material and a preparation process thereof, and its specific implementation manner is the same as that of Example 1, except that there is no impact nickel plating layer, and the preparation process of the stainless steel nickel-plated steel material comprises the following steps:

[0078] (1) performing surface pretreatment on a stainless steel substrate before plating to obtain a stainless steel substrate to be plated;

[0079] (2) washing the stainless steel substrate to be plated with water and then electroplating to form a dark nickel coating on the surface of the stainless steel substrate to be plated;

[0080] (3) after washing, secondary electrodeposition is performed on the dark nickel coating to form a bright nickel coating;

[0081] (4) After washing, drying and rolling, the product is obtained.

[0082] Comparative Example 2

[0083] Comparative Example 2 of the present invention provides a stainless steel nickel-plated steel material and a preparation process thereof, and its specific implementation manner is the same as that of Example 1, except that the thickness of the dark nickel plating layer is 0.4 μm, and the thickness of the bright nickel plating layer is 0.4 μm.

[0084] Performance Testing

[0085] The stainless steel nickel-plated steel provided in the embodiment and the comparative example was subjected to a bending test. Specifically, the stainless steel nickel-plated steel provided in the embodiment and the comparative example was cut into 200 mm*300 mm test samples, and the test samples were bent. The bending force was controlled to be the same, and whether the coating fell off at the bending of the guessed sample was observed. The results are shown in Tables 1 and Figure 1-4 .

[0086] Table 1

[0087] Example Bending test Example 1 The coating has not fallen off Example 2 The coating has not fallen off Comparative Example 1 Plating peeling off Comparative Example 2 Plating peeling off

Claims

1. A stainless steel nickel-plated steel material, characterized in that: From bottom to top, it includes at least: a stainless steel substrate, an impact nickel plating layer, a dark nickel plating layer, and a bright nickel plating layer.

2. The stainless steel nickel-plated steel material according to claim 1, characterized in that: The thickness of the impact nickel plating layer is 0.1-0.5 μm.

3. The stainless steel nickel-plated steel material according to claim 2, characterized in that: The grain size of the impact nickel plating layer is 70-100nm.

4. The stainless steel nickel-plated steel material according to claim 3, characterized in that: The thickness of the dark nickel plating layer is 0.1-5 μm.

5. The stainless steel nickel-plated steel material according to claim 4, characterized in that: The thickness of the bright nickel plating layer is 0.1-5 μm.

6. A process for preparing the stainless steel nickel-plated steel material according to any one of claims 1 to 5, characterized in that: At least the following steps are included: (1) performing surface pretreatment on a stainless steel substrate before plating to obtain a stainless steel substrate to be plated; (2) washing the stainless steel substrate to be plated with water and then electroplating the substrate to be plated to form an impact nickel coating on the surface of the stainless steel substrate; (3) after washing, secondary electrodeposition is performed to form a dark nickel coating on the surface of the impact nickel coating; (4) after washing, three times of electrodeposition are performed on the dark nickel coating to form a bright nickel coating; (5) After washing, drying and rolling, the product is obtained.

7. The process for preparing the stainless steel nickel-plated steel material according to claim 6, characterized in that: The surface pretreatment before plating in step (1) at least includes electrochemical degreasing, cleaning, electrolytic pickling activation, and hydrochloric acid activation.

8. The process for preparing the stainless steel nickel-plated steel material according to claim 6, characterized in that: The electrolyte solution for electrodeposition in step (2) at least comprises: 80-100 mL / L of HCl and 200-220 g / L of NiCl2·6H2O, and the solvent is water.

9. The process for preparing the stainless steel nickel-plated steel material according to claim 6, characterized in that: The electrolyte solution for secondary electrodeposition in step (3) at least comprises: NiSO4·6H2O 260-300g / L, NiCl2·6H2O35-45g / L, H3BO335-45g / L, the solvent is water.

10. The process for preparing the stainless steel nickel-plated steel material according to claim 6, characterized in that: The electrolyte solution for the three electrodepositions in step (4) at least comprises: NiSO4·6H2O 280-320g / L, NiCl2·6H2O35-45g / L, H3BO335-45g / L, the solvent is water.

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