High-strength weather-resistant nickel-plated steel strip and preparation method thereof

Abstract

The invention discloses a high-strength weather-resistant nickel-plated steel strip and a preparation method thereof, relates to the technical field of nickel-plated steel strips, and aims to improve the corrosion resistance and weather resistance of the steel strip, a composite coating is prepared on the surface of the steel strip on the basis of preparation of the steel strip; according to the method, hardness difference between different plating layers is achieved through component difference between the different plating layers, when the alkaline nickel plating layer is prepared, a large amount of phosphorus element is added into the alkaline nickel plating layer, a large amount of amorphous structures appear in the plating layer due to addition of the phosphorus element, the hardness of the nickel plating layer is reduced, and the bonding performance between the nickel plating layer and a steel substrate is improved; on the basis, graphene is further introduced into the coating, the graphene has extremely high wear resistance and self-lubricating performance, the wear resistance of the outermost layer of the coating can be effectively improved through introduction of the graphene, coating damage caused after the steel strip is subjected to external friction is avoided, and therefore the service life of the coating is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of nickel-plated steel strips, in particular 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. Currently, more than 1 / 6 of the world's steel production is lost every year due to atmospheric corrosion. Currently, most anti-corrosion measures for steel materials are coating protection, among which chromium, nickel and zinc coatings are the main ones. However, during use, the coatings often break or even peel off from the steel, causing defects and serious degradation of atmospheric corrosion and weather resistance, and ultimately leading to a reduction in steel strength. Summary of the invention

[0003] The object of the present invention is to provide a high-strength weather-resistant nickel-plated steel strip and a preparation method thereof, so as to solve the problems raised in the prior art.

[0004] To achieve the above object, the present invention provides the following technical solution: a method for preparing a high-strength weather-resistant nickel steel strip, comprising the following steps: 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 nickel plating solution. During electroplating, apply an external magnetic field with a strength of 0.25-0.4T, control the temperature of the alkaline plating solution to 35-45℃, and the current density to 1.5-3A / dm 2 , the pulse frequency is 10Hz; 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; 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 3 , after electroplating to the required thickness, the electroplating is terminated; 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.

[0005] Furthermore, 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: 1.45-175%, Ni: 0.25-0.80%, and the remainder is iron and other inevitable impurities.

[0006] 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; and the thickness of the graphene nickel-phosphorus layer is 0.5-0.8 μm.

[0007] Furthermore, in step S21, the surface of the steel strip is cleaned with an alkali solution having a temperature of 65-75° C. during degreasing; 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.

[0008] Furthermore, 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.

[0009] Furthermore, in step S22, the alkaline nickel plating solution comprises the following components: 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.

[0010] Furthermore, in step S23, the acid nickel plating solution comprises the following components: 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.

[0011] Further, in step S24, the graphene nickel plating 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.

[0013] Compared with the prior art, the present invention has the following beneficial effects: In order to improve the corrosion and weather resistance of the steel strip, the present invention prepares a composite coating on the surface of the steel strip on the basis of preparing the steel strip; The invention realizes the difference in hardness between different plating layers by using the difference in components between different plating layers. When preparing the alkaline nickel plating layer, the invention adds a large amount of phosphorus element therein, and the invention also applies a magnetic field externally when preparing the alkaline nickel plating layer. Under the action of the strong magnetic field, the solid solubility of the phosphorus element will increase, so that the alkaline nickel plating layer finally prepared contains a large amount of phosphorus element. The addition of the phosphorus element will cause a large amount of amorphous structure to appear in the plating layer, thereby reducing the hardness of the nickel plating layer, buffering stress and improving the bonding performance with the steel substrate. In addition, the system selected when preparing the alkaline nickel plating layer is an alkaline nickel plating solution, which can effectively reduce the probability of hydrogen embrittlement and reduce the adverse effects of nickel plating compared with the acidic nickel plating solution. On this basis, the present application further prepares a thicker acidic nickel plating layer and an outermost graphene nickel plating layer; graphene itself has extremely high wear resistance and self-lubricating properties, and the introduction of graphene can effectively improve the wear resistance of the outermost layer of the coating, avoiding coating damage caused by the steel strip after being subjected to external friction, thereby increasing the coating life, and the present invention also performs a tempering treatment on the steel strip after the coating is prepared, while further removing the cold rolling stress, it can promote the diffusion of metal elements between the coatings and enhance the bonding strength between the coatings, and the maximum tempering temperature of the present application is 680-750°C, at which temperature, the hydrogen atoms between the metal lattices can be effectively migrated and dissipated, further reducing the occurrence of hydrogen embrittlement. DETAILED DESCRIPTION

[0014] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0015] In the examples and comparative examples of the present application, the raw materials of the steel strip blank components are as follows: 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%, the balance is iron and unavoidable impurities; The graphene used in this application is XF001H type single-layer graphene; Example 1. A method for preparing a high-strength weather-resistant nickel-plated steel strip, comprising the following steps: 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 1250°C, the hot rolling finishing temperature is 860°C, and the hot rolling curling temperature is 645°C; S13. After the hot rolling is completed, the temperature of the ingot is lowered to 75°C and then cold rolling is continued with a cold rolling reduction rate of 70%; S14. After the cold rolling is completed, the cold rolled ingot is annealed. During the annealing, the heating temperature is controlled to be 580°C. After heating for 25 seconds, the temperature is raised to 725°C. After continuing to heat for 40 seconds, the temperature is lowered to 500°C. After cooling for 20 seconds, 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; When removing oil, the surface of the steel strip is cleaned with an alkali solution at a temperature of 70°C, wherein the alkali solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of sodium trihydrogen phosphate; After degreasing, the surface of the steel strip is cleaned with a 25wt% hydrochloric acid solution for 30s, and then the surface hydrochloric acid is washed again with deionized water and dried to complete the activation of the steel strip surface; S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with an intensity of 0.25T, control the temperature of the alkaline electroplating solution to 45°C, and the current density to 1.5A / dm 2 , the pulse frequency is 10Hz; The alkaline nickel plating solution comprises: 15 g / L nickel sulfate, 20 g / L sodium hypophosphite, 30 g / L sodium citrate, 0.2 mL / L tetraethylene pentamine, and 2.5 g / L sodium carbonate; S23. Place the steel strip after alkaline electroplating in an acidic electroplating solution. During electroplating, the temperature of the acidic electroplating solution is controlled to be 60°C and the current density is 4A / dm 2 , the pulse frequency is 10Hz; The acidic nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 30 g / L boric acid, and 0.5 g / L sodium dodecyl sulfate. S24. The steel strip blank after acid electroplating is placed in the graphene electroplating solution again. During electroplating, the electroplating solution temperature is controlled to be 90°C and the current density is 5A / dm 3, after electroplating to the required thickness, the electroplating is terminated; The graphene nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 25 g / L boric acid, 0.8 g / L sodium dodecyl sulfate, 60 mg / L graphene, and 120 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 at 600°C. After heating for 20 seconds, the temperature is raised to 750°C. After continuing to heat for 45 seconds, the temperature is lowered to 550°C. After cooling for 15 seconds, the tempering is completed to obtain a high-strength weather-resistant nickel-plated steel strip.

[0016] Example 2. A method for preparing a high-strength weather-resistant nickel-plated steel strip, comprising the following steps: Compared with Example 1, this embodiment increases the content of sodium hypophosphite in step S22; 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 1250°C, the hot rolling finishing temperature is 860°C, and the hot rolling curling temperature is 645°C; S13. After the hot rolling is completed, the temperature of the ingot is lowered to 75°C and then cold rolling is continued with a cold rolling reduction rate of 70%; S14. After the cold rolling is completed, the cold rolled ingot is annealed. During the annealing, the heating temperature is controlled to be 580°C. After heating for 25 seconds, the temperature is raised to 725°C. After continuing to heat for 40 seconds, the temperature is lowered to 500°C. After cooling for 20 seconds, 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; When removing oil, the surface of the steel strip is cleaned with an alkali solution at a temperature of 70°C, wherein the alkali solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of sodium trihydrogen phosphate; After degreasing, the surface of the steel strip is cleaned with a 25wt% hydrochloric acid solution for 30s, and then the surface hydrochloric acid is washed again with deionized water and dried to complete the activation of the steel strip surface; S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with an intensity of 0.25T, control the temperature of the alkaline electroplating solution to 45°C, and the current density to 1.5A / dm 2 , the pulse frequency is 10Hz; The alkaline nickel plating solution comprises: 15 g / L nickel sulfate, 30 g / L sodium hypophosphite, 30 g / L sodium citrate, 0.2 mL / L tetraethylene pentamine, and 2.5 g / L sodium carbonate; S23. Place the steel strip after alkaline electroplating in an acidic electroplating solution. During electroplating, the temperature of the acidic electroplating solution is controlled to be 60°C and the current density is 4A / dm 2 , the pulse frequency is 10Hz; The acidic nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 30 g / L boric acid, and 0.5 g / L sodium dodecyl sulfate. S24. The steel strip blank after acid electroplating is placed in the graphene electroplating solution again. During electroplating, the electroplating solution temperature is controlled to be 90°C and the current density is 5A / dm 3 , after electroplating to the required thickness, the electroplating is terminated; The graphene nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 25 g / L boric acid, 0.8 g / L sodium dodecyl sulfate, 60 mg / L graphene, and 120 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 at 600°C. After heating for 20 seconds, the temperature is raised to 750°C. After continuing to heat for 45 seconds, the temperature is lowered to 550°C. After cooling for 15 seconds, the tempering is completed to obtain a high-strength weather-resistant nickel-plated steel strip.

[0017] Example 3. A method for preparing a high-strength weather-resistant nickel-plated steel strip, comprising the following steps: Compared with Example 1, this embodiment increases the magnetic field strength in step S22; 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 1250°C, the hot rolling finishing temperature is 860°C, and the hot rolling curling temperature is 645°C; S13. After the hot rolling is completed, the temperature of the ingot is lowered to 75°C and then cold rolling is continued with a cold rolling reduction rate of 70%; S14. After the cold rolling is completed, the cold rolled ingot is annealed. During the annealing, the heating temperature is controlled to be 580°C. After heating for 25 seconds, the temperature is raised to 725°C. After continuing to heat for 40 seconds, the temperature is lowered to 500°C. After cooling for 20 seconds, 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; When removing oil, the surface of the steel strip is cleaned with an alkali solution at a temperature of 70°C, wherein the alkali solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of sodium trihydrogen phosphate; After degreasing, the surface of the steel strip is cleaned with a 25wt% hydrochloric acid solution for 30s, and then the surface hydrochloric acid is washed again with deionized water and dried to complete the activation of the steel strip surface; S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with an intensity of 0.4T, control the temperature of the alkaline electroplating solution to 45°C, and the current density to 1.5A / dm 2 , the pulse frequency is 10Hz; The alkaline nickel plating solution comprises: 15 g / L nickel sulfate, 20 g / L sodium hypophosphite, 30 g / L sodium citrate, 0.2 mL / L tetraethylene pentamine, and 2.5 g / L sodium carbonate; S23. The steel strip after alkaline electroplating is placed in an acid electroplating solution. During electroplating, the temperature of the acid electroplating solution is controlled to be 60°C and the current density is 4A / dm 2 , the pulse frequency is 10Hz; The acidic nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 30 g / L boric acid, and 0.5 g / L sodium dodecyl sulfate. S24. The steel strip blank after acid electroplating is placed in the graphene electroplating solution again. During electroplating, the electroplating solution temperature is controlled to be 90°C and the current density is 5A / dm 3 , after electroplating to the required thickness, the electroplating is terminated; The graphene nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 25 g / L boric acid, 0.8 g / L sodium dodecyl sulfate, 60 mg / L graphene, and 120 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 at 600°C. After heating for 20 seconds, the temperature is raised to 750°C. After continuing to heat for 45 seconds, the temperature is lowered to 550°C. After cooling for 15 seconds, the tempering is completed to obtain a high-strength weather-resistant nickel-plated steel strip.

[0018] Example 4. A method for preparing a high-strength weather-resistant nickel-plated steel strip, comprising the following steps: Compared with Example 1, this embodiment increases the graphene content in step S24; 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 1250°C, the hot rolling finishing temperature is 860°C, and the hot rolling curling temperature is 645°C; S13. After the hot rolling is completed, the temperature of the ingot is lowered to 75°C and then cold rolling is continued with a cold rolling reduction rate of 70%; S14. After the cold rolling is completed, the cold rolled ingot is annealed. During the annealing, the heating temperature is controlled to be 580°C. After heating for 25 seconds, the temperature is raised to 725°C. After continuing to heat for 40 seconds, the temperature is lowered to 500°C. After cooling for 20 seconds, 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; When removing oil, the surface of the steel strip is cleaned with an alkali solution at a temperature of 70°C, wherein the alkali solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of sodium trihydrogen phosphate; After degreasing, the surface of the steel strip is cleaned with a 25wt% hydrochloric acid solution for 30s, and then the surface hydrochloric acid is washed again with deionized water and dried to complete the activation of the steel strip surface; S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with an intensity of 0.25T, control the temperature of the alkaline electroplating solution to 45°C, and the current density to 1.5A / dm 2 , the pulse frequency is 10Hz; The alkaline nickel plating solution comprises: 15 g / L nickel sulfate, 20 g / L sodium hypophosphite, 30 g / L sodium citrate, 0.2 mL / L tetraethylene pentamine, and 2.5 g / L sodium carbonate; S23. The steel strip after alkaline electroplating is placed in an acid electroplating solution. During electroplating, the temperature of the acid electroplating solution is controlled to be 60°C and the current density is 4A / dm 2 , the pulse frequency is 10Hz; The acidic nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 30 g / L boric acid, and 0.5 g / L sodium dodecyl sulfate. S24. The steel strip blank after acid electroplating is placed in the graphene electroplating solution again. During electroplating, the electroplating solution temperature is controlled to be 90°C and the current density is 5A / dm 3 , after electroplating to the required thickness, the electroplating is terminated; The graphene nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 25 g / L boric acid, 0.8 g / L sodium dodecyl sulfate, 180 mg / L graphene, and 120 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 at 600°C. After heating for 20 seconds, the temperature is raised to 750°C. After continuing to heat for 45 seconds, the temperature is lowered to 550°C. After cooling for 15 seconds, the tempering is completed to obtain a high-strength weather-resistant nickel-plated steel strip.

[0019] Example 5. A method for preparing a high-strength weather-resistant nickel-plated steel strip, comprising the following steps: Compared with Example 1, this embodiment reduces the tempering time in step S3; 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 1250°C, the hot rolling finishing temperature is 860°C, and the hot rolling curling temperature is 645°C; S13. After the hot rolling is completed, the temperature of the ingot is lowered to 75°C and then cold rolling is continued with a cold rolling reduction rate of 70%; S14. After the cold rolling is completed, the cold rolled ingot is annealed. During the annealing, the heating temperature is controlled to be 580°C. After heating for 25 seconds, the temperature is raised to 725°C. After continuing to heat for 40 seconds, the temperature is lowered to 500°C. After cooling for 20 seconds, 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; When removing oil, the surface of the steel strip is cleaned with an alkali solution at a temperature of 70°C, wherein the alkali solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of sodium trihydrogen phosphate; After degreasing, the surface of the steel strip is cleaned with a 25wt% hydrochloric acid solution for 30s, and then the surface hydrochloric acid is washed again with deionized water and dried to complete the activation of the steel strip surface; S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with an intensity of 0.25T, control the temperature of the alkaline electroplating solution to 45°C, and the current density to 1.5A / dm 2 , the pulse frequency is 10Hz; The alkaline nickel plating solution comprises: 15 g / L nickel sulfate, 20 g / L sodium hypophosphite, 30 g / L sodium citrate, 0.2 mL / L tetraethylene pentamine, and 2.5 g / L sodium carbonate; S23. The steel strip after alkaline electroplating is placed in an acid electroplating solution. During electroplating, the temperature of the acid electroplating solution is controlled to be 60°C and the current density is 4A / dm 2 , the pulse frequency is 10Hz; The acidic nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 30 g / L boric acid, and 0.5 g / L sodium dodecyl sulfate. S24. The steel strip blank after acid electroplating is placed in the graphene electroplating solution again. During electroplating, the electroplating solution temperature is controlled to be 90°C and the current density is 5A / dm 3 , after electroplating to the required thickness, the electroplating is terminated; The graphene nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 25 g / L boric acid, 0.8 g / L sodium dodecyl sulfate, 60 mg / L graphene, and 120 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 at 600°C. After heating for 10 seconds, the temperature is raised to 750°C. After continuing to heat for 15 seconds, the temperature is lowered to 550°C. After cooling for 10 seconds, the tempering is completed to obtain a high-strength weather-resistant nickel-plated steel strip.

[0020] Comparative Example 1. A method for preparing a high-strength weather-resistant nickel-plated steel strip, comprising the following steps: Compared with Example 1, this comparative example did not perform step S3; 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 1250°C, the hot rolling finishing temperature is 860°C, and the hot rolling curling temperature is 645°C; S13. After the hot rolling is completed, the temperature of the ingot is lowered to 75°C and then cold rolling is continued with a cold rolling reduction rate of 70%; S14. After the cold rolling is completed, the cold rolled ingot is annealed. During the annealing, the heating temperature is controlled to be 580°C. After heating for 25 seconds, the temperature is raised to 725°C. After continuing to heat for 40 seconds, the temperature is lowered to 500°C. After cooling for 20 seconds, 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; When removing oil, the surface of the steel strip is cleaned with an alkali solution at a temperature of 70°C, wherein the alkali solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of sodium trihydrogen phosphate; After degreasing, the surface of the steel strip is cleaned with a 25wt% hydrochloric acid solution for 30s, and then the surface hydrochloric acid is washed again with deionized water and dried to complete the activation of the steel strip surface; S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with an intensity of 0.25T, control the temperature of the alkaline electroplating solution to 45°C, and the current density to 1.5A / dm 2 , the pulse frequency is 10Hz; The alkaline nickel plating solution comprises: 15 g / L nickel sulfate, 20 g / L sodium hypophosphite, 30 g / L sodium citrate, 0.2 mL / L tetraethylene pentamine, and 2.5 g / L sodium carbonate; S23. Place the steel strip after alkaline electroplating in an acidic electroplating solution. During electroplating, the temperature of the acidic electroplating solution is controlled to be 60°C and the current density is 4A / dm 2 , the pulse frequency is 10Hz; The acidic nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 30 g / L boric acid, and 0.5 g / L sodium dodecyl sulfate. S24. The steel strip blank after acid electroplating is placed in the graphene electroplating solution again. During electroplating, the electroplating solution temperature is controlled to be 90°C and the current density is 5A / dm 3 After electroplating to the required thickness, the electroplating is terminated to obtain a high-strength weather-resistant nickel-plated steel strip; The graphene nickel plating solution comprises the following components: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 25 g / L boric acid, 0.8 g / L sodium dodecyl sulfate, 60 mg / L graphene, and 120 mg / L sodium dodecylbenzene sulfonate.

[0021] Comparative Example 2. A method for preparing a high-strength weather-resistant nickel-plated steel strip, comprising the following steps: Compared with Example 1, this comparative example does not perform step S24; 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 1250°C, the hot rolling finishing temperature is 860°C, and the hot rolling curling temperature is 645°C; S13. After the hot rolling is completed, the temperature of the ingot is lowered to 75°C and then cold rolling is continued with a cold rolling reduction rate of 70%; S14. After the cold rolling is completed, the cold rolled ingot is annealed. During the annealing, the heating temperature is controlled to be 580°C. After heating for 25 seconds, the temperature is raised to 725°C. After continuing to heat for 40 seconds, the temperature is lowered to 500°C. After cooling for 20 seconds, 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; When removing oil, the surface of the steel strip is cleaned with an alkali solution at a temperature of 70°C, wherein the alkali solution contains 15 g / L of sodium hydroxide, 40 g / L of sodium carbonate, and 45 g / L of sodium trihydrogen phosphate; After degreasing, the surface of the steel strip is cleaned with a 25wt% hydrochloric acid solution for 30s, and then the surface hydrochloric acid is washed again with deionized water and dried to complete the activation of the steel strip surface; S22. Place the steel strip in an alkaline nickel plating solution. During electroplating, apply an external magnetic field with an intensity of 0.25T, control the temperature of the alkaline electroplating solution to 45°C, and the current density to 1.5A / dm 2 , the pulse frequency is 10Hz; The alkaline nickel plating solution comprises: 15 g / L nickel sulfate, 20 g / L sodium hypophosphite, 30 g / L sodium citrate, 0.2 mL / L tetraethylene pentamine, and 2.5 g / L sodium carbonate; S23. The steel strip after alkaline electroplating is placed in an acid electroplating solution. During electroplating, the temperature of the acid electroplating solution is controlled to be 60°C and the current density is 4A / dm 2 , the pulse frequency is 10Hz; The acidic nickel plating solution comprises: 180 g / L nickel sulfate, 25 g / L sodium phosphite, 15 g / L sodium acetate, 30 g / L boric acid, and 0.5 g / L sodium dodecyl sulfate. 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 at 600°C. After heating for 20 seconds, the temperature is raised to 750°C. After continuing to heat for 45 seconds, the temperature is lowered to 550°C. After cooling for 15 seconds, the tempering is completed to obtain a high-strength weather-resistant nickel-plated steel strip.

[0022] Testing: The steel strips prepared in Examples 1-5 and Comparative Examples 1-2 were prepared into test samples with a steel strip blank thickness of 1 mm, a basic 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; and the performance of the test samples was tested; The tensile strength of the samples prepared in Examples 1-5 and Comparative Examples 1-2 was tested using a universal tensile testing machine; According to GB / T6461-2002, a sodium chloride solution with a pH value of 6.5-7.2 and a concentration of 5±0.5% was prepared at a temperature of 35°C and a relative humidity of 95% at a rate of 1.5 mL / h·cm 2 After spraying the sample surface with a spray volume of 8 hours continuously and immersing it for 16 hours, its corrosion resistance is rated; After the samples prepared in Examples 1-5 and Comparative Examples 1-2 were bent at right angles 5 times, they were again subjected to corrosion resistance rating tests; The wear amount of the sample was tested using a SUJ2 steel ball with a normal load of 3N, a rotation speed of 300rpm, and a friction time of 0.5h. The test results are shown in the table below;

[0023] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in 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 nickel plating solution. During electroplating, apply an external magnetic field with a strength of 0.25-0.4T, control the temperature of the alkaline plating solution to 35-45℃, and the current density to 1.5-3A / dm 2 , the pulse frequency is 10Hz; 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; 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 3 , after electroplating to the required thickness, the electroplating is terminated; 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: 1.45-175%, 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 is 0.7-1.1 μm; the thickness of the acidic nickel-phosphorus layer is 2.5-3 μm; and the thickness of the graphene nickel-phosphorus layer 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. The method for preparing a high-strength weather-resistant nickel steel strip according to claim 1, characterized in that: In step S22, the alkaline nickel plating 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.

7. The method for preparing a high-strength weather-resistant nickel steel strip according to claim 1, characterized in that: In step S23, the acid nickel plating 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.

8. The method for preparing a high-strength weather-resistant nickel steel strip according to claim 1, characterized in that: In step S24, the graphene nickel plating 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.

9. A high-strength weather-resistant nickel steel strip prepared by the preparation method according to any one of claims 1 to 8.

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