A high-strength weather-resistant nickel-plated steel strip and its preparation method

Abstract

The present invention discloses a high-strength weather-resistant nickel-plated steel strip and a preparation method thereof, which relates to the technical field of nickel-plated steel strips. In order to improve the corrosion resistance and weather resistance of the steel strip, the present invention prepares a composite coating on its surface on the basis of preparing the steel strip; by the difference in the composition between different coatings, the present invention realizes the difference in hardness between different coatings. When preparing the alkaline nickel-plated layer, the present invention adds a large amount of phosphorus element thereto. The addition of the phosphorus element will cause a large number of amorphous structures to appear in the coating, reduce the hardness of the nickel coating, and improve the bonding performance with the steel substrate. On this basis, the present application further introduces graphene into the coating. Graphene itself has extremely high wear resistance and self-lubricating performance. The introduction of graphene can effectively improve the wear resistance of the outermost layer of the coating, avoid the coating damage caused by the steel strip being subjected to external friction, and thus improve the coating life.

Description

Technical Field

[0001] The present invention relates to the technical field of nickel-plated steel strips, and specifically to a high-strength weather-resistant nickel-plated steel strip and a preparation method thereof. Background Art

[0002] Atmospheric corrosion is one of the main forms of damage to steel materials at present. Currently, about 1 / 6 of the world's annual steel production is continuously lost due to atmospheric corrosion;

[0003] Currently, most of the anti-corrosion measures for steel materials are coating protection, among which chromium, nickel, and zinc coatings are often used. However, during use, the coating often has phenomena and defects such as breakage and peeling between the coating and the steel, resulting in a serious decline in the atmospheric corrosion resistance and weather resistance, and ultimately leading to a reduction in the strength of the steel. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-strength weather-resistant nickel-plated steel strip and a preparation method thereof to solve the problems raised in the prior art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A preparation method of a high-strength weather-resistant nickel-plated steel strip, comprising the following steps:

[0006] S1. Prepare a steel strip blank;

[0007] S11. Mix the raw materials and obtain a cast blank after smelting and casting;

[0008] S12. Perform hot rolling on the cast blank, control the heating and discharging temperature to be 1200 - 1300 °C, the final rolling temperature of hot rolling to be 800 - 1000 °C, and the coiling temperature of hot rolling to be 600 - 700 °C;

[0009] S13. After the hot rolling is completed, wait for the temperature of the cast blank to drop to 60 - 80 °C, and then continue cold rolling, with the cold rolling reduction rate being 55 - 90%;

[0010] S14. After the cold rolling is completed, anneal the cold-rolled cast blank. During annealing, control the heating temperature to be 550 - 600 °C. After heating for 15 - 30 s, raise the temperature to 680 - 750 °C, continue heating for 30 - 50 s, then lower the temperature to 450 - 550 °C, and cool for 20 - 30 s to complete the annealing and obtain the steel strip blank;

[0011] S2. Prepare a nickel-plated layer;

[0012] S21. Degrease and activate the surface of the steel strip blank;

[0013] S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with a strength of 0.25 - 0.4 T, control the temperature of the alkaline electroplating solution at 35 - 45 °C, and the current density at 1.5 - 3 A / dm 2 , and the pulse frequency at 10 Hz;

[0014] S23. Place the steel strip blank after alkaline electroplating in an acidic electroplating solution. During electroplating, control the temperature of the acidic electroplating solution at 40 - 60 °C, and the current density at 3 - 8 A / dm 2 , and the pulse frequency at 10 Hz;

[0015] S24. Place the steel strip blank after acidic electroplating in a graphene electroplating solution again. During electroplating, control the temperature of the electroplating solution at 80 - 90 °C, and the current density at 5 - 8 A / dm 3 , and end electroplating after electroplating to the required thickness;

[0016] S3. After the plating is completed, wash the surface of the steel strip with deionized water. After drying, temper the steel strip. During tempering, control the heating temperature at 550 - 600 °C. After heating for 10 - 25 s, raise the temperature to 680 - 750 °C, continue heating for 15 - 45 s, then lower the temperature to 450 - 550 °C, and cool for 10 - 20 s to complete tempering, obtaining a high-strength weather-resistant nickel-plated steel strip.

[0017] Furthermore, the chemical component weight percentages of the steel strip blank are: C: 0.55 - 1.05%, Si: 0.24 - 0.36%, Mn: 0.3 - 0.4%, P: 0 - 0.035%, S: 0 - 0.007%, Cr: 1.45 - 1.75%, Ni: 0.25 - 0.80%, and the balance is iron and other inevitable impurities.

[0018] Furthermore, the thickness of the alkaline nickel-phosphorus layer is 0.7 - 1.1 μm; the thickness of the acidic nickel-phosphorus layer is 2.5 - 3 μm; the thickness of the graphene nickel-phosphorus layer is 0.5 - 0.8 μm.

[0019] Furthermore, in step S21, when degreasing, use an alkali solution with a temperature of 65 - 75 °C to clean the surface of the steel strip;

[0020] Among them, the alkali solution contains 15 - 30 g / L of sodium hydroxide, 40 - 80 g / L of sodium carbonate, and 40 - 60 g / L of trisodium phosphate.

[0021] Furthermore, in step S21, when activating, use a hydrochloric acid solution with a concentration of 20 - 25 wt% to clean the surface of the steel strip for 15 - 30 s, then use deionized water to wash the hydrochloric acid on the surface again, and dry to complete the activation of the steel strip surface.

[0022] Further, in step S22, the composition of the alkaline nickel plating solution is: nickel sulfate 15 - 30 g / L, sodium hypophosphite 20 - 30 g / L, sodium citrate 30 - 40 g / L, tetraethylenepentamine 0.1 - 0.3 mL / L, and sodium carbonate 2 - 3 g / L.

[0023] Further, in step S23, the composition of the acidic nickel plating solution is: nickel sulfate 180 - 240 g / L, sodium phosphite 10 - 45 g / L, sodium acetate 10 - 20 g / L, boric acid 20 - 30 g / L, and sodium dodecyl sulfate 0.5 - 0.8 g / L.

[0024] Further, in step S24, the composition of the graphene nickel plating solution is: nickel sulfate 180 - 240 g / L, sodium phosphite 10 - 45 g / L, sodium acetate 10 - 20 g / L, boric acid 20 - 30 g / L, sodium dodecyl sulfate 0.5 - 0.8 g / L, graphene 60 - 180 mg / L, and sodium dodecylbenzenesulfonate 80 - 240 mg / L.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] In order to improve the corrosion and weather resistance of the steel strip, the present invention prepares a composite coating on its surface based on the preparation of the steel strip.

[0027] By the difference in the composition between different coatings, the present invention realizes the difference in hardness between different coatings. When preparing the alkaline nickel plating layer, the present invention adds a large amount of phosphorus element thereto, and also applies a magnetic field externally during the preparation of the alkaline nickel plating layer. Under the action of the strong magnetic field, the solid solution performance of the phosphorus element will increase, so that the finally prepared alkaline nickel plating layer contains a large amount of phosphorus element. The addition of the phosphorus element will cause a large number of amorphous structures to appear in the coating, thereby reducing the hardness of the nickel coating, buffering stress while improving the bonding performance with the steel substrate. Moreover, the system selected for preparing the alkaline nickel plating layer is the alkaline nickel plating solution, which can effectively reduce the probability of hydrogen embrittlement and reduce the adverse effects brought by nickel plating compared with the acidic nickel plating solution.

[0028] On this basis, the present application further prepares an acidic nickel plating layer with a relatively thick thickness and a graphene nickel plating layer on the outermost side; graphene itself has extremely high wear resistance and self-lubricating performance. The introduction of graphene can effectively improve the wear resistance of the outermost layer of the coating, avoid the coating damage caused by the external friction of the steel strip, thereby improving the coating life. Moreover, the present invention also performs tempering treatment on the steel strip after preparing the coating. While further removing the cold rolling stress, it can promote the diffusion of metal elements between the coatings and improve the bonding force between the coatings. And the maximum tempering temperature of the present application is 680 - 750 °C. At this temperature, the hydrogen atoms between the metal lattices can be effectively migrated and dissipated, further reducing the occurrence of hydrogen embrittlement. Detailed implementation mode

[0029] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] In the embodiments and comparative examples of this application, the component raw materials of the steel strip blank are as follows:

[0031] C: 0.74 - 0.76%, Si: 0.25 - 0.27%, Mn: 0.34 - 0.36%, P: 0.135%, S: 0.002 - 0.005%, Cr: 1.52 - 1.55%, Ni: 0.74 - 0.75%, and the balance is iron and unavoidable impurities;

[0032] The graphene used in this application is XF001H type monolayer graphene;

[0033] Example 1. A preparation method of a high-strength weather-resistant nickel-plated steel strip, comprising the following steps:

[0034] S1. Prepare a steel strip blank;

[0035] S11. Mix the raw materials, and after smelting and casting, obtain a cast billet;

[0036] S12. Perform hot rolling on the cast billet, control the heating and discharging temperature at 1250 °C, the final rolling temperature of hot rolling at 860 °C, and the coiling temperature of hot rolling at 645 °C;

[0037] After hot rolling, when the temperature of the cast billet drops to 75 °C, continue cold rolling, and the cold rolling reduction rate is 70%;

[0038] After cold rolling, anneal the cold-rolled cast billet. During annealing, control the heating temperature at 580 °C, after heating for 25 s, raise the temperature to 725 °C, continue heating for 40 s, then lower the temperature to 500 °C, cool for 20 s, and complete annealing to obtain a steel strip blank;

[0039] S2. Prepare a nickel plating layer;

[0040] S21. Degrease and activate the surface of the steel strip blank;

[0041] When degreasing, use an alkaline solution with a temperature of 70 °C to clean the surface of the steel strip. The alkaline solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of trisodium phosphate;

[0042] After degreasing, use a hydrochloric acid solution with a concentration of 25 wt% to clean the surface of the steel strip for 30 s, then use deionized water to wash the hydrochloric acid on the surface again, and dry to complete the activation of the steel strip surface;

[0043] S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with a strength of 0.25 T, control the temperature of the alkaline electroplating solution at 45 °C, and the current density at 1.5 A / dm 2 , and the pulse frequency at 10 Hz;

[0044] Among them, the composition of the alkaline nickel plating solution is: nickel sulfate 15 g / L, sodium hypophosphite 20 g / L, sodium citrate 30 g / L, tetraethylenepentamine 0.2 mL / L, sodium carbonate 2.5 g / L;

[0045] S23. Place the steel strip blank after alkaline electroplating in an acidic nickel plating solution. During electroplating, control the temperature of the acidic electroplating solution at 60 °C, and the current density at 4 A / dm 2 , and the pulse frequency at 10 Hz;

[0046] Among them, the composition of the acidic nickel plating solution is: nickel sulfate 180 g / L, sodium phosphite 25 g / L, sodium acetate 15 g / L, boric acid 30 g / L, sodium dodecyl sulfate 0.5 g / L;

[0047] S24. Place the steel strip blank after acidic electroplating in the graphene electroplating solution again. During electroplating, control the temperature of the electroplating solution at 90 °C, and the current density at 5 A / dm 3 , and end electroplating after electroplating to the required thickness;

[0048] Among them, the composition of the graphene nickel plating solution is: nickel sulfate 180 g / L, sodium phosphite 25 g / L, sodium acetate 15 g / L, boric acid 25 g / L, sodium dodecyl sulfate 0.8 g / L, graphene 60 mg / L, sodium dodecylbenzenesulfonate 120 mg / L;

[0049] S3. After the electroplating is completed, wash the surface of the steel strip with deionized water. After drying, temper the steel strip. During tempering, control the heating temperature at 600 °C. After heating for 20 s, raise the temperature to 750 °C, continue heating for 45 s, then lower the temperature to 550 °C, and cool for 15 s to complete tempering, obtaining a high-strength weather-resistant nickel-plated steel strip.

[0050] Example 2. A method for preparing a high-strength weather-resistant nickel-plated steel strip, comprising the following steps:

[0051] Compared with Example 1, the content of sodium hypophosphite in step S22 is increased in this example;

[0052] S1. Prepare a steel strip blank;

[0053] S11. Mix the raw materials and obtain a casting blank after smelting and casting;

[0054] S12. Hot-roll the continuous casting billet, control the heating and discharging temperature at 1250 °C, the finishing rolling temperature of hot rolling at 860 °C, and the coiling temperature of hot rolling at 645 °C;

[0055] S13. After hot rolling, wait for the temperature of the continuous casting billet to drop to 75 °C, and then continue cold rolling with a cold rolling reduction rate of 70%;

[0056] S14. After cold rolling, anneal the cold-rolled continuous casting billet. During annealing, control the heating temperature at 580 °C. After heating for 25 s, raise the temperature to 725 °C, continue heating for 40 s, then lower the temperature to 500 °C, and cool for 20 s to complete annealing and obtain a steel strip blank;

[0057] S2. Prepare a nickel plating layer;

[0058] S21. Degrease and activate the surface of the steel strip blank;

[0059] When degreasing, use an alkaline solution at 70 °C to clean the surface of the steel strip. The alkaline solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of trisodium phosphate;

[0060] After degreasing, use a 25 wt% hydrochloric acid solution to clean the surface of the steel strip for 30 s, then use deionized water to wash the hydrochloric acid on the surface again, and dry to complete the activation of the steel strip surface;

[0061] S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with an intensity of 0.25 T, control the temperature of the alkaline electroplating solution at 45 °C, and the current density at 1.5 A / dm 2 , and the pulse frequency at 10 Hz;

[0062] Among them, the components of the alkaline nickel plating solution are: 15 g / L of nickel sulfate, 30 g / L of sodium hypophosphite, 30 g / L of sodium citrate, 0.2 mL / L of tetraethylenepentamine, and 2.5 g / L of sodium carbonate;

[0063] S23. Place the steel strip blank after alkaline electroplating in an acidic electroplating solution. During electroplating, control the temperature of the acidic electroplating solution at 60 °C and the current density at 4 A / dm 2 , and the pulse frequency at 10 Hz;

[0064] Among them, the components of the acidic nickel plating solution are: 180 g / L of nickel sulfate, 25 g / L of sodium phosphite, 15 g / L of sodium acetate, 30 g / L of boric acid, and 0.5 g / L of sodium dodecyl sulfate;

[0065] S24. Place the steel strip blank after acidic electroplating in the graphene electroplating solution again. During electroplating, control the temperature of the electroplating solution at 90 °C and the current density at 5 A / dm 3 , and stop electroplating after electroplating to the required thickness;

[0066] Among them, the components of the nickel-plated graphene solution are: nickel sulfate 180 g / L, sodium hypophosphite 25 g / L, sodium acetate 15 g / L, boric acid 25 g / L, sodium dodecyl sulfate 0.8 g / L, graphene 60 mg / L, and sodium dodecylbenzenesulfonate 120 mg / L;

[0067] S3. After the plating is completed, wash the surface of the steel strip with deionized water. After drying, temper the steel strip. During tempering, control the heating temperature at 600 °C. After heating for 20 s, raise the temperature to 750 °C, continue heating for 45 s, then lower the temperature to 550 °C, and cool for 15 s to complete tempering, obtaining a high-strength weather-resistant nickel-plated steel strip.

[0068] Example 3. A preparation method of a high-strength weather-resistant nickel-plated steel strip, comprising the following steps:

[0069] Compared with Example 1, the magnetic field strength in step S22 is increased in this example;

[0070] S1. Prepare a steel strip blank;

[0071] S11. Mix the raw materials and obtain a casting blank after smelting and casting;

[0072] S12. Perform hot rolling on the casting blank, control the heating and discharging temperature at 1250 °C, the final rolling temperature of hot rolling at 860 °C, and the coiling temperature of hot rolling at 645 °C;

[0073] S13. After hot rolling is completed, wait for the temperature of the casting blank to drop to 75 °C and continue cold rolling, with a cold rolling reduction rate of 70%;

[0074] S14. After cold rolling is completed, anneal the cold-rolled casting blank. During annealing, control the heating temperature at 580 °C. After heating for 25 s, raise the temperature to 725 °C, continue heating for 40 s, then lower the temperature to 500 °C, and cool for 20 s to complete annealing, obtaining a steel strip blank;

[0075] S2. Prepare a nickel-plated layer;

[0076] S21. Degrease and activate the surface of the steel strip blank;

[0077] When degreasing, use an alkaline solution at 70 °C to clean the surface of the steel strip. The alkaline solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of trisodium phosphate;

[0078] After degreasing, use a 25 wt% hydrochloric acid solution to clean the surface of the steel strip for 30 s, then use deionized water to wash the surface hydrochloric acid again, and dry to complete the activation of the steel strip surface;

[0079] S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with a strength of 0.4 T, control the temperature of the alkaline electroplating solution at 45 °C, and the current density at 1.5 A / dm 2 , and the pulse frequency at 10 Hz;

[0080] Among them, the composition of the alkaline nickel plating solution is: nickel sulfate 15 g / L, sodium hypophosphite 20 g / L, sodium citrate 30 g / L, tetraethylenepentamine 0.2 mL / L, sodium carbonate 2.5 g / L;

[0081] S23. Place the steel strip blank after alkaline electroplating in an acidic nickel plating solution. During electroplating, control the temperature of the acidic electroplating solution at 60 °C and the current density at 4 A / dm 2 , and the pulse frequency at 10 Hz;

[0082] Among them, the composition of the acidic nickel plating solution is: nickel sulfate 180 g / L, sodium phosphite 25 g / L, sodium acetate 15 g / L, boric acid 30 g / L, sodium dodecyl sulfate 0.5 g / L;

[0083] S24. Place the steel strip blank after acidic electroplating in the graphene electroplating solution again. During electroplating, control the temperature of the electroplating solution at 90 °C and the current density at 5 A / dm 3 , and end electroplating after electroplating to the required thickness;

[0084] Among them, the composition of the graphene nickel plating solution is: nickel sulfate 180 g / L, sodium phosphite 25 g / L, sodium acetate 15 g / L, boric acid 25 g / L, sodium dodecyl sulfate 0.8 g / L, graphene 60 mg / L, sodium dodecylbenzenesulfonate 120 mg / L;

[0085] S3. After the plating is completed, wash the surface of the steel strip with deionized water. After drying, temper the steel strip. During tempering, control the heating temperature at 600 °C, heat for 20 s, then raise the temperature to 750 °C, continue to heat for 45 s, then lower the temperature to 550 °C, and cool for 15 s to complete tempering and obtain a high-strength weather-resistant nickel-plated steel strip.

[0086] Example 4. A method for preparing a high-strength weather-resistant nickel-plated steel strip, comprising the following steps:

[0087] Compared with Example 1, this example increases the graphene content in step S24;

[0088] S1. Prepare a steel strip blank;

[0089] S11. Mix the raw materials and obtain a casting blank after smelting and casting;

[0090] S12. Hot-roll the continuous casting billet, control the heating and discharging temperature at 1250 °C, the final rolling temperature of hot rolling at 860 °C, and the coiling temperature of hot rolling at 645 °C;

[0091] S13. After the hot rolling is completed, wait for the temperature of the continuous casting billet to drop to 75 °C, and then continue with cold rolling, with the cold rolling reduction rate being 70%;

[0092] S14. After the cold rolling is completed, anneal the cold-rolled continuous casting billet. During annealing, control the heating temperature at 580 °C. After heating for 25 s, raise the temperature to 725 °C. After continuing to heat for 40 s, lower the temperature to 500 °C. After cooling for 20 s, the annealing is completed to obtain a steel strip blank;

[0093] S2. Prepare a nickel plating layer;

[0094] S21. Degrease and activate the surface of the steel strip blank;

[0095] When degreasing, use an alkaline solution at 70 °C to clean the surface of the steel strip. The alkaline solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of trisodium phosphate;

[0096] After degreasing, use a 25 wt% hydrochloric acid solution to clean the surface of the steel strip for 30 s. Then, use deionized water to wash the hydrochloric acid on the surface again and dry it to complete the activation of the steel strip surface;

[0097] S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with a strength of 0.25 T, control the temperature of the alkaline electroplating solution at 45 °C, and the current density at 1.5 A / dm 2 , and the pulse frequency at 10 Hz;

[0098] Among them, the components of the alkaline nickel plating solution are: 15 g / L of nickel sulfate, 20 g / L of sodium hypophosphite, 30 g / L of sodium citrate, 0.2 mL / L of tetraethylenepentamine, and 2.5 g / L of sodium carbonate;

[0099] S23. Place the steel strip blank after alkaline electroplating in an acidic electroplating solution. During electroplating, control the temperature of the acidic electroplating solution at 60 °C, and the current density at 4 A / dm 2 , and the pulse frequency at 10 Hz;

[0100] Among them, the components of the acidic nickel plating solution are: 180 g / L of nickel sulfate, 25 g / L of sodium phosphite, 15 g / L of sodium acetate, 30 g / L of boric acid, and 0.5 g / L of sodium dodecyl sulfate;

[0101] S24. Place the steel strip blank after acidic electroplating in the graphene electroplating solution again. During electroplating, control the temperature of the electroplating solution at 90 °C, and the current density at 5 A / dm 3 , and end the electroplating after electroplating to the required thickness;

[0102] Among them, the components of the nickel-plated graphene solution are: nickel sulfate 180 g / L, sodium hypophosphite 25 g / L, sodium acetate 15 g / L, boric acid 25 g / L, sodium dodecyl sulfate 0.8 g / L, graphene 180 mg / L, and sodium dodecyl benzene sulfonate 120 mg / L;

[0103] S3. After the plating is completed, wash the surface of the steel strip with deionized water. After drying, temper the steel strip. During tempering, control the heating temperature at 600 °C. After heating for 20 s, raise the temperature to 750 °C, continue heating for 45 s, then lower the temperature to 550 °C, and cool for 15 s to complete tempering, obtaining a high-strength weather-resistant nickel-plated steel strip.

[0104] Example 5. A method for preparing a high-strength weather-resistant nickel-plated steel strip, comprising the following steps:

[0105] Compared with Example 1, the tempering duration in step S3 is reduced in this example;

[0106] S1. Prepare a steel strip blank;

[0107] S11. Mix the raw materials and obtain a casting blank after smelting and casting;

[0108] S12. Perform hot rolling on the casting blank, control the heating and discharging temperature at 1250 °C, the final rolling temperature of hot rolling at 860 °C, and the coiling temperature of hot rolling at 645 °C;

[0109] S13. After hot rolling is completed, wait for the temperature of the casting blank to drop to 75 °C and continue cold rolling, with a cold rolling reduction rate of 70%;

[0110] S14. After cold rolling is completed, anneal the cold-rolled casting blank. During annealing, control the heating temperature at 580 °C. After heating for 25 s, raise the temperature to 725 °C, continue heating for 40 s, then lower the temperature to 500 °C, and cool for 20 s to complete annealing, obtaining a steel strip blank;

[0111] S2. Prepare a nickel-plated layer;

[0112] S21. Perform degreasing and activation treatment on the surface of the steel strip blank;

[0113] When degreasing, use an alkaline solution at 70 °C to clean the surface of the steel strip. The alkaline solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of sodium hydrogen phosphate;

[0114] After degreasing, use a 25 wt% hydrochloric acid solution to clean the surface of the steel strip for 30 s, then use deionized water to wash the surface hydrochloric acid again, and dry to complete the activation of the steel strip surface;

[0115] S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with a strength of 0.25 T, control the temperature of the alkaline electroplating solution at 45 °C, and the current density at 1.5 A / dm 2 , and the pulse frequency at 10 Hz;

[0116] Among them, the composition of the alkaline nickel plating solution is: nickel sulfate 15 g / L, sodium hypophosphite 20 g / L, sodium citrate 30 g / L, tetraethylenepentamine 0.2 mL / L, sodium carbonate 2.5 g / L;

[0117] S23. Place the steel strip blank after alkaline electroplating in an acidic nickel plating solution. During electroplating, control the temperature of the acidic electroplating solution at 60 °C, and the current density at 4 A / dm 2 , and the pulse frequency at 10 Hz;

[0118] Among them, the composition of the acidic nickel plating solution is: nickel sulfate 180 g / L, sodium phosphite 25 g / L, sodium acetate 15 g / L, boric acid 30 g / L, sodium dodecyl sulfate 0.5 g / L;

[0119] S24. Place the steel strip blank after acidic electroplating in the graphene electroplating solution again. During electroplating, control the temperature of the electroplating solution at 90 °C, and the current density at 5 A / dm 3 , and stop electroplating after electroplating to the required thickness;

[0120] Among them, the composition of the graphene nickel plating solution is: nickel sulfate 180 g / L, sodium phosphite 25 g / L, sodium acetate 15 g / L, boric acid 25 g / L, sodium dodecyl sulfate 0.8 g / L, graphene 60 mg / L, sodium dodecylbenzenesulfonate 120 mg / L;

[0121] S3. After the plating is completed, wash the surface of the steel strip with deionized water. After drying, temper the steel strip. During tempering, control the heating temperature at 600 °C, heat for 10 s, then raise the temperature to 750 °C, continue heating for 15 s, then lower the temperature to 550 °C, and cool for 10 s to complete tempering, obtaining a high-strength weather-resistant nickel-plated steel strip.

[0122] Comparative Example 1. A method for preparing a high-strength weather-resistant nickel-plated steel strip includes the following steps:

[0123] Compared with Example 1, this comparative example does not perform the treatment of step S3;

[0124] S1. Prepare a steel strip blank;

[0125] S11. Mix the raw materials and obtain a casting blank after smelting and casting;

[0126] S12. Hot-roll the continuous casting billet, control the heating and discharging temperature at 1250 °C, the final rolling temperature of hot rolling at 860 °C, and the coiling temperature of hot rolling at 645 °C;

[0127] S13. After hot rolling, wait until the temperature of the continuous casting billet drops to 75 °C, and then continue cold rolling with a cold rolling reduction rate of 70%;

[0128] S14. After cold rolling, anneal the cold-rolled continuous casting billet. During annealing, control the heating temperature at 580 °C. After heating for 25 s, raise the temperature to 725 °C, continue heating for 40 s, then lower the temperature to 500 °C, and cool for 20 s to complete annealing and obtain a steel strip blank;

[0129] S2. Prepare a nickel plating layer;

[0130] S21. Degrease and activate the surface of the steel strip blank;

[0131] When degreasing, use an alkaline solution at 70 °C to clean the surface of the steel strip. The alkaline solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of trisodium phosphate;

[0132] After degreasing, use a 25 wt% hydrochloric acid solution to clean the surface of the steel strip for 30 s, then use deionized water to wash the hydrochloric acid on the surface again, and dry to complete the activation of the steel strip surface;

[0133] S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with an external magnetic field strength of 0.25 T, control the temperature of the alkaline electroplating solution at 45 °C, and the current density at 1.5 A / dm 2 , and the pulse frequency at 10 Hz;

[0134] Among them, the components of the alkaline nickel plating solution are: 15 g / L of nickel sulfate, 20 g / L of sodium hypophosphite, 30 g / L of sodium citrate, 0.2 mL / L of tetraethylenepentamine, and 2.5 g / L of sodium carbonate;

[0135] S23. Place the steel strip blank after alkaline electroplating in an acidic electroplating solution. During electroplating, control the temperature of the acidic electroplating solution at 60 °C, and the current density at 4 A / dm 2 , and the pulse frequency at 10 Hz;

[0136] Among them, the components of the acidic nickel plating solution are: 180 g / L of nickel sulfate, 25 g / L of sodium phosphite, 15 g / L of sodium acetate, 30 g / L of boric acid, and 0.5 g / L of sodium dodecyl sulfate;

[0137] S24. Place the steel strip blank after acidic electroplating in the graphene electroplating solution again. During electroplating, control the temperature of the electroplating solution at 90 °C, and the current density at 5 A / dm 3, after electroplating to the required thickness, the electroplating is ended to obtain a high-strength weather-resistant nickel-plated steel strip;

[0138] Among them, the components of the graphene nickel plating solution are: nickel sulfate 180 g / L, sodium hypophosphite 25 g / L, sodium acetate 15 g / L, boric acid 25 g / L, sodium dodecyl sulfate 0.8 g / L, graphene 60 mg / L, and sodium dodecyl benzene sulfonate 120 mg / L.

[0139] Comparative Example 2. A method for preparing a high-strength weather-resistant nickel-plated steel strip, comprising the following steps:

[0140] Compared with Example 1, this comparative example does not perform the treatment of step S24;

[0141] S1. Prepare a steel strip blank;

[0142] S11. Mix the raw materials and obtain a casting blank after smelting and casting;

[0143] S12. Perform hot rolling on the casting blank, control the heating furnace outlet temperature at 1250 °C, the hot rolling final rolling temperature at 860 °C, and the hot rolling coiling temperature at 645 °C;

[0144] S13. After the hot rolling is completed, wait for the temperature of the casting blank to drop to 75 °C and continue cold rolling, and the cold rolling reduction rate is 70%;

[0145] S14. After the cold rolling is completed, anneal the cold-rolled casting blank. During annealing, control the heating temperature at 580 °C, after heating for 25 s, raise the temperature to 725 °C, continue heating for 40 s, then lower the temperature to 500 °C, cool for 20 s, and complete the annealing to obtain a steel strip blank;

[0146] S2. Prepare a nickel plating layer;

[0147] S21. Degrease and activate the surface of the steel strip blank;

[0148] When degreasing, use an alkaline solution with a temperature of 70 °C to clean the surface of the steel strip. The alkaline solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of trisodium phosphate;

[0149] After degreasing, use a 25 wt% hydrochloric acid solution to clean the surface of the steel strip for 30 s, then use deionized water to wash the surface hydrochloric acid again, and dry to complete the activation of the steel strip surface;

[0150] S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with an intensity of 0.25 T, control the temperature of the alkaline electroplating solution at 45 °C, and the current density at 1.5 A / dm 2 , and the pulse frequency is 10 Hz;

[0151] Among them, the components of the alkaline nickel plating solution are: nickel sulfate 15 g / L, sodium hypophosphite 20 g / L, sodium citrate 30 g / L, tetraethylenepentamine 0.2 mL / L, and sodium carbonate 2.5 g / L;

[0152] S23. Place the steel strip blank after alkaline electroplating in the acidic electroplating solution. During electroplating, control the temperature of the acidic electroplating solution at 60 °C and the current density at 4 A / dm 2 , and the pulse frequency at 10 Hz;

[0153] Among them, the components of the acidic nickel plating solution are: nickel sulfate 180 g / L, sodium phosphite 25 g / L, sodium acetate 15 g / L, boric acid 30 g / L, and sodium dodecyl sulfate 0.5 g / L;

[0154] S3. After the plating is completed, wash the surface of the steel strip with deionized water. After drying, temper the steel strip. During tempering, control the heating temperature at 600 °C. After heating for 20 s, raise the temperature to 750 °C, continue heating for 45 s, then lower the temperature to 550 °C, and cool for 15 s to complete the tempering, obtaining a high-strength weather-resistant nickel-plated steel strip.

[0155] Detection: Prepare test specimens with a steel strip blank thickness of 1 mm, an alkaline nickel-phosphorus layer thickness of 1 μm, an acidic nickel-phosphorus layer thickness of 3 μm, and a graphene nickel-phosphorus layer thickness of 0.5 μm from the steel strips prepared in Examples 1-5 and Comparative Examples 1-2; conduct performance tests on them;

[0156] Use a universal tensile testing machine to test the tensile strength of the samples prepared in Examples 1-5 and Comparative Examples 1-2;

[0157] According to GB / T6461-2002, configure a sodium chloride solution with a pH value of 6.5 - 7.2 and a concentration of 5 ± 0.5%. In an environment with an ambient temperature of 35 °C and a relative humidity of 95%, continuously spray the surface of the specimen at a spray rate of 1.5 mL / h·cm 2 for 8 h and continue to immerse for 16 h, and then rate its corrosion resistance;

[0158] After bending the samples prepared in Examples 1-5 and Comparative Examples 1-2 at a right angle 5 times, conduct a corrosion resistance rating test on them again;

[0159] Use a SUJ2 steel ball, with a normal load of 3 N, a rotation speed of 300 rpm, and a friction time of 0.5 h to detect the wear amount of the test specimen;

[0160] The test results are shown in the following table;

[0161]

[0162] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a high-strength weather-resistant nickel steel strip, characterized in that: The following steps are involved: S1. Preparing a steel strip blank; S11. The raw materials are mixed, smelted and cast to obtain a cast billet; S12. The ingot is hot rolled, the heating furnace temperature is controlled to be 1200-1300°C, the hot rolling finishing temperature is 800-1000°C, and the hot rolling curling temperature is 600-700°C; S13. After hot rolling, the temperature of the ingot is reduced to 60-80°C, and cold rolling is continued, with a cold rolling reduction rate of 55-90%; S14. After the cold rolling is completed, the cold rolled ingot is annealed. During the annealing, the heating temperature is controlled to be 550-600°C. After heating for 15-30s, the temperature is raised to 680-750°C. After continuing to heat for 30-50s, the temperature is lowered to 450-550°C. After cooling for 20-30s, the annealing is completed to obtain a steel strip blank. S2. Preparing a nickel-plated layer; S21. Degreasing and activating the surface of the steel strip body; S22. Place the steel strip in an alkaline electroplating solution. During electroplating, apply an external magnetic field with a strength of 0.25-0.4T, control the temperature of the alkaline electroplating solution to 35-45℃, and the current density to 1.5-3A / dm 2 , the pulse frequency is 10Hz; The alkaline electroplating solution comprises: 15-30 g / L nickel sulfate, 20-30 g / L sodium hypophosphite, 30-40 g / L sodium citrate, 0.1-0.3 mL / L tetraethylene pentamine, and 2-3 g / L sodium carbonate; S23. Place the steel strip after alkaline electroplating in an acidic electroplating solution. During electroplating, control the temperature of the acidic electroplating solution to 40-60°C and the current density to 3-8A / dm 2 , the pulse frequency is 10Hz; The acidic electroplating solution comprises: 180-240 g / L nickel sulfate, 10-45 g / L sodium phosphite, 10-20 g / L sodium acetate, 20-30 g / L boric acid, and 0.5-0.8 g / L sodium dodecyl sulfate; S24. The steel strip blank after acid electroplating is placed in the graphene electroplating solution again. During electroplating, the temperature of the electroplating solution is controlled to be 80-90°C and the current density is 5-8A / dm 2 , after electroplating to the required thickness, the electroplating is terminated; The graphene electroplating solution comprises: 180-240 g / L nickel sulfate, 10-45 g / L sodium phosphite, 10-20 g / L sodium acetate, 20-30 g / L boric acid, 0.5-0.8 g / L sodium dodecyl sulfate, 60-180 mg / L graphene, and 80-240 mg / L sodium dodecylbenzene sulfonate; S3. After plating, the surface of the steel strip is washed with deionized water. After drying, the steel strip is tempered. During tempering, the heating temperature is controlled to be 550-600℃. After heating for 10-25s, the temperature is raised to 680-750℃. After continuing to heat for 15-45s, the temperature is lowered to 450-550℃. After cooling for 10-20s, the tempering is completed to obtain a high-strength weather-resistant nickel-plated steel strip.

2. The method for preparing a high-strength weather-resistant nickel steel strip according to claim 1, characterized in that: The chemical components of the steel strip blank are as follows by weight: C: 0.55-1.05%, Si: 0.24-0.36%, Mn: 0.3-0.4%, P: 0-0.035%, S: 0-0.007%, Cr: 1.45-1.75%, Ni: 0.25-0.80%, and the remainder is iron and other inevitable impurities.

3. The method for preparing a high-strength weather-resistant nickel steel strip according to claim 1, characterized in that: The thickness of the alkaline nickel-phosphorus layer formed after electroplating with an alkaline electroplating solution is 0.7-1.1 μm; The thickness of the acidic nickel-phosphorus layer formed after electroplating with an acidic electroplating solution is 2.5-3 μm; the thickness of the graphene nickel-phosphorus layer formed after electroplating with a graphene electroplating solution is 0.5-0.8 μm.

4. The method for preparing a high-strength weather-resistant nickel steel strip according to claim 1, characterized in that: In step S21, during degreasing, an alkali solution at a temperature of 65-75° C. is used to clean the surface of the steel strip; The alkali solution contains 15-30 g / L of sodium hydroxide, 40-80 g / L of sodium carbonate, and 40-60 g / L of sodium trihydrogen phosphate.

5. The method for preparing a high-strength weather-resistant nickel steel strip according to claim 1, characterized in that: In step S21, during activation, the surface of the steel strip is cleaned with a hydrochloric acid solution having a concentration of 20-25wt% for 15-30s, and then the surface hydrochloric acid is washed again with deionized water and dried to complete the activation of the surface of the steel strip.

6. A high-strength weather-resistant nickel steel strip prepared by the preparation method according to any one of claims 1 to 5.

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