Manufacturing method of aluminum-silicon-copper coated steel plate

Abstract

The invention belongs to the technical field of hot dipping, and particularly relates to a manufacturing method of an aluminum-silicon-copper coated steel plate, an Al-Si-Cu coating is formed on the surface of a steel plate substrate, and the manufacturing method comprises the following steps: 1) melting an Al-Si-Fe alloy ingot to prepare an alloy plating solution; (2) the steel plate base body is subjected to alkali washing, electrolytic degreasing treatment, continuous annealing treatment, hot dipping, air knife purging and cooling after plating, and then an Al-Si plated steel plate is formed; depositing a Cu film on the surface of the substrate by using a magnetron sputtering coating technology; and heating through a heating furnace to obtain the Al-Si-Cu coated steel plate. The preparation method has the advantages that a Cu system is selected as a main antibacterial substance, and the composite coating is prepared from the Al-Si coated steel plate by adopting a deposition and diffusion two-step method by virtue of a high-temperature diffusion mechanism, so that element distribution and an organization structure in the coating have antibacterial and antibacterial properties.

Description

Technical Field

[0001] The invention belongs to the technical field of hot-dip plating, and in particular relates to a method for manufacturing an aluminum-silicon-copper coated steel plate. Background Art

[0002] Al-Si was originally designed to prevent oxidation and decarburization of automotive parts during the hot stamping process. Today, Al-Si-coated steel is no longer limited to the automotive sector. Due to its high-temperature resistance, Al-Si-coated steel has also begun to find application in home appliances, such as steam ovens and heating furnaces, which operate in high-temperature environments. Studies have shown that Al-Si-coated steel can maintain a bright appearance even at temperatures below 450°C.

[0003] Driven by a pursuit of health, products with antimicrobial properties are increasingly popular among consumers. Based on this development philosophy, antimicrobial properties are being combined with Al-Si coated steel sheets to create steel sheets that combine high-temperature resistance with antimicrobial properties. Currently, the main antimicrobial methods include inorganic, organic, and photocatalytic methods. Starting from the perspective of inorganic antimicrobial agents, inorganic antimicrobial materials are primarily heavy metal cations, most of which have strong bactericidal properties. From a safety perspective, their safety order is Ag > Co > Ni > Al > Zn > Cu = Fe > Mn > Sn > Ba > Mg > Ca. Currently, Ag, Cu, and Zn are the most widely used. When bacteria come into contact with metal ions, the metal ions can destroy the bacterial structure, or they can enter the bacterial cell and bind to the enzymes that support bacterial proliferation, inactivating the enzymes and thus achieving their antimicrobial and antibacterial properties.

[0004] In the prior art, patent application number: CN200910231746.2 discloses a method for producing continuous hot-dip aluminum-silicon-copper-magnesium alloy steel plates. A continuous hot-dip plating process is used to plate aluminum, silicon, copper, and magnesium on the surface of cold-rolled steel plates to improve the surface quality of the aluminum-plated plates and make the surface of the aluminum-plated plates smooth and flat. However, the antibacterial and antimicrobial properties of such steel plates are not mentioned. Patent application number: CN201710353213.6 discloses a treatment process for enhancing the corrosion resistance of hot-dip galvanized steel plates. A hot-dip plating process is used to galvanize the surface of the steel plates. The ζ phase in the coating is a continuous and dense structure. The galvanized layer is tightly bonded to the steel plates. The steel plates are then treated with liquid nitrogen to increase their hardness and impact toughness. The surface is then passivated to form a dense protective film, thereby improving the corrosion resistance of the hot-dip galvanized steel plates. This method only enhances the corrosion resistance of the steel plates and does not bring about any antibacterial or antimicrobial effects. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a method for manufacturing aluminum-silicon-copper coated steel plates, in which a composite coating is obtained by a "two-step method" of prefabricated coating plus diffusion annealing, so that the element distribution and organizational structure in the coating have certain antibacterial properties.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A method for manufacturing an aluminum-silicon-copper coated steel plate, forming an Al-Si-Cu coating on the surface of a steel plate substrate, specifically comprising the following steps:

[0008] 1) melting an Al-Si-Fe alloy ingot to prepare an alloy plating solution;

[0009] 2) The steel plate substrate is subjected to alkali washing and electrolytic degreasing treatment, continuous annealing treatment, hot dip coating, air knife blowing, and post-coating cooling to form an Al-Si coated steel plate;

[0010] 3) depositing a Cu thin film on the surface of the Al-Si coated steel plate using a magnetron sputtering coating technique;

[0011] 4) The Al-Si coated steel plate with the Cu film is placed in a vacuum heating furnace for heating to allow the coating and the surface film to fully diffuse, thereby obtaining an Al-Si-Cu coated steel plate.

[0012] The chemical composition of the Al-Si-Fe alloy ingot in step 1) is as follows by weight: Si: 5% to 15%, Fe: 1% to 5%, other impurity elements <1%, and the remainder is Al.

[0013] In the step 2), the steel plate substrate is a cold-rolled steel plate, and the chemical composition of the cold-rolled steel plate is as follows by weight: C: 0.005% to 1.0%, Si: 0.02% to 2.0%, Mn: 0.2% to 2.5%, S≤0.1%, P≤0.2%, Al: 0.005% to 0.2%, B≤0.1%, Nb≤0.1%, V≤0.1%, Ti≤0.1%, Cr≤0.5%, Ni≤0.5%, Mo≤0.5%, and the rest is Fe and unavoidable impurities.

[0014] In the alkali washing process in step 2), the alkali solution used is NaOH solution, the mass fraction of the NaOH solution is 3% to 7%, and the temperature of the NaOH solution is 70 to 85° C.; the current in the electrolytic degreasing treatment is controlled at 1 to 12A.

[0015] In the continuous annealing treatment in step 2), the annealing temperature is 700-850° C. and the strip speed is 35-150 m / min.

[0016] The hot-dip coating temperature in step 2) is 650-680° C., and the hot-dip coating time is controlled to be 3-5 seconds, wherein the temperature of the steel plate substrate entering the pot is 5-10° C. higher than the hot-dip coating temperature.

[0017] The coating thickness of the Al-Si coated steel plate obtained in step 2) is 10 to 35 μm.

[0018] In the magnetron sputtering coating process of step 3), the sputtering current is 0.2-0.8A, the temperature of the Al-Si coated steel plate is 100-300°C, and the sputtering power is 50-200W.

[0019] The thickness of the Cu film formed on the surface of the Al-Si coated steel plate in step 3) is 1 to 5 μm.

[0020] In the step 3), the heating temperature in the vacuum heating furnace is 500-600° C., and the heating time is 1-5 minutes.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention utilizes a diffusion mechanism to impart both high-temperature resistance and antibacterial properties to Al-Si coated steel sheets, while also providing a surface strengthening effect. Using Cu as the primary antibacterial agent, and leveraging the high-temperature diffusion mechanism, a composite coating is produced using a two-step "deposition + diffusion" process. This results in a coating with antibacterial properties, resulting in a distribution of elements and a microstructure within the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the aluminum-silicon-copper coating of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0025] A method for manufacturing an aluminum-silicon-copper coated steel plate, forming an Al-Si-Cu coating on the surface of a steel plate substrate, specifically comprising the following steps:

[0026] 1) An Al-Si-Fe alloy ingot is melted to prepare an alloy plating solution; the chemical composition of the Al-Si-Fe alloy ingot is as follows by weight: Si: 5% to 15%, Fe: 1% to 5%, other impurity elements <1%, and the remainder being Al.

[0027] 2) The steel plate substrate is a cold-rolled steel plate, and the chemical composition of the cold-rolled steel plate is as follows by weight: C: 0.005% to 1.0%, Si: 0.02% to 2.0%, Mn: 0.2% to 2.5%, S≤0.1%, P≤0.2%, Al: 0.005% to 0.2%, B≤0.1%, Nb≤0.1%, V≤0.1%, Ti≤0.1%, Cr≤0.5%, Ni≤0.5%, Mo≤0.5%, and the rest is Fe and unavoidable impurities.

[0028] The steel plate substrate is subjected to alkali washing and electrolytic degreasing treatment, continuous annealing, hot dip coating, air knife purging, and post-coating cooling to form an Al-Si coated steel plate with a thickness of 10 to 35 μm.

[0029] During the alkaline washing process, the alkali solution used is a NaOH solution with a mass fraction of 3% to 7% and a temperature of 70-85°C. During the electrolytic degreasing process, the current is controlled at 1-12A. During the continuous annealing process, the annealing temperature is 700-850°C and the strip speed is 35-150m / min. The hot-dip coating temperature is 650-680°C and the hot-dip coating time is controlled to be 3-5s. The steel substrate entry temperature is 5-10°C higher than the hot-dip coating temperature.

[0030] 3) A Cu film is deposited on the Al-Si coated steel plate using magnetron sputtering technology to form a Cu film with a thickness of 1 to 5 μm on the surface of the Al-Si coated steel plate. During the magnetron sputtering process, a sputtering current of 0.2 to 0.8 A, a temperature of 100 to 300° C. for the Al-Si coated steel plate, and a sputtering power of 50 to 200 W are used to ensure a uniform film layer.

[0031] 4) The Al-Si coated steel sheet with the Cu film is placed in a vacuum heating furnace and heated to allow the coating to fully diffuse with the surface film, thereby producing an Al-Si-Cu coated steel sheet. The heating temperature in the vacuum heating furnace is 500-600°C, and the heating time is 1-5 minutes.

[0032] See Figure 1 , aluminum-silicon-copper coated steel plate and its manufacturing method, in specific embodiments, the chemical composition of the Al-Si-Fe alloy ingot is shown in Table 1; the preparation process parameters of the Al-Si coated steel plate in each embodiment are shown in Table 2; the Cu film is deposited on the surface of the Al-Si coated steel plate using magnetron sputtering coating technology, and the process parameters of the magnetron sputtering process are shown in Table 3; the thickness of the Al-Si coating and the Cu film in each embodiment are shown in Table 4.

[0033] Table 1 Proportion of each element in the alloy plating solution (mass ratio wt.%)

[0034] Si Fe Al Example 1 9.6 2.6 margin Example 2 8.5 3.3 margin Example 3 10.3 2.8 margin Example 4 11.2 2.5 margin Example 5 10.7 2.1 margin

[0035] Table 2 Preparation process parameters of Al-Si coated steel plates

[0036]

[0037] Table 3 Magnetron sputtering process parameters

[0038] Sputtering current / A Substrate temperature / ℃ Sputtering power / w Example 1 0.6 150 140 Example 2 0.4 210 120 Example 3 0.3 160 90 Example 4 0.7 150 170 Example 5 0.5 130 150

[0039] Table 4 Al-Si coating thickness, Cu film thickness

[0040] Al-Si coating / μm Cu film / μm Example 1 19 2 Example 2 14 1 Example 3 27 1 Example 4 25 3 Example 5 31 2

[0041] Table 5 Parameter control of vacuum high temperature diffusion process

[0042] Heating temperature / ℃ Heating time / min Example 1 546 2 Example 2 572 4 Example 3 558 3.5 Example 4 569 2.5

[0043] This invention utilizes a diffusion mechanism to impart both high-temperature resistance and antibacterial properties to Al-Si coated steel sheets, while also providing a surface strengthening effect. Using Cu as the primary antibacterial agent, and leveraging the high-temperature diffusion mechanism, a composite coating is produced using a two-step "deposition + diffusion" process. This results in a coating with an elemental distribution and microstructure that imparts antibacterial properties, achieving an antibacterial rate of 80% to 95%.

Claims

1. A method for manufacturing an aluminum-silicon-copper coated steel plate, characterized in that: Forming an Al-Si-Cu coating on the surface of a steel plate substrate specifically includes the following steps: 1) melting an Al-Si-Fe alloy ingot to prepare an alloy plating solution; 2) The steel plate substrate is subjected to alkali washing and electrolytic degreasing treatment, continuous annealing treatment, hot dip coating, air knife blowing, and post-coating cooling to form an Al-Si coated steel plate; 3) depositing a Cu thin film on the surface of the Al-Si coated steel plate using a magnetron sputtering coating technique; 4) The Al-Si coated steel plate with the Cu film is placed in a vacuum heating furnace for heating to allow the coating and the surface film to fully diffuse, thereby obtaining an Al-Si-Cu coated steel plate.

2. The method for manufacturing an aluminum-silicon-copper coated steel plate according to claim 1, characterized in that: The chemical composition of the Al-Si-Fe alloy ingot in step 1) is as follows by weight: Si: 5% to 15%, Fe: 1% to 5%, other impurity elements <1%, and the remainder is Al.

3. The method for manufacturing an aluminum-silicon-copper coated steel plate according to claim 1, characterized in that: In the step 2), the steel plate substrate is a cold-rolled steel plate, and the chemical composition of the cold-rolled steel plate is as follows by weight: C: 0.005% to 1.0%, Si: 0.02% to 2.0%, Mn: 0.2% to 2.5%, S≤0.1%, P≤0.2%, Al: 0.005% to 0.2%, B≤0.1%, Nb≤0.1%, V≤0.1%, Ti≤0.1%, Cr≤0.5%, Ni≤0.5%, Mo≤0.5%, and the rest is Fe and unavoidable impurities.

4. The method for manufacturing an aluminum-silicon-copper coated steel plate according to claim 1, characterized in that: In the alkali washing process in step 2), the alkali solution used is NaOH solution, the mass fraction of the NaOH solution is 3% to 7%, and the temperature of the NaOH solution is 70 to 85° C.; the current in the electrolytic degreasing treatment is controlled at 1 to 12A.

5. The method for manufacturing an aluminum-silicon-copper coated steel plate according to claim 1, characterized in that: In the continuous annealing treatment in step 2), the annealing temperature is 700-850° C. and the strip speed is 35-150 m / min.

6. The method for manufacturing an aluminum-silicon-copper coated steel plate according to claim 1, characterized in that: The hot-dip coating temperature in step 2) is 650-680° C., and the hot-dip coating time is controlled to be 3-5 seconds, wherein the temperature of the steel plate substrate entering the pot is 5-10° C. higher than the hot-dip coating temperature.

7. The method for manufacturing an aluminum-silicon-copper coated steel plate according to claim 1, characterized in that: The coating thickness of the Al-Si coated steel plate obtained in step 2) is 10 to 35 μm.

8. The method for manufacturing an aluminum-silicon-copper coated steel plate according to claim 1, characterized in that: In the magnetron sputtering coating process of step 3), the sputtering current is 0.2-0.8A, the temperature of the Al-Si coated steel plate is 100-300°C, and the sputtering power is 50-200W.

9. The method for manufacturing an aluminum-silicon-copper coated steel plate according to claim 1, characterized in that: The thickness of the Cu film formed on the surface of the Al-Si coated steel plate in step 3) is 1 to 5 μm.

10. The method for manufacturing an aluminum-silicon-copper coated steel plate according to claim 1, characterized in that: In the step 4), the heating temperature in the vacuum heating furnace is 500-600° C., and the heating time is 1-5 minutes.

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