Aluminum-silicon-copper-magnesium coated steel plate with antibacterial property and corrosion resistance and manufacturing method of aluminum-silicon-copper-magnesium coated steel plate

Abstract

The invention discloses an aluminum-silicon-copper-magnesium coated steel plate with antibacterial performance and corrosion resistance and a manufacturing method thereof, and belongs to the field of hot dipping. The method comprises the following steps: (a) carrying out alkali washing, electrolytic degreasing, continuous annealing, hot dipping, air knife purging and cooling after plating on a cold-rolled substrate to form an aluminum-silicon coating steel plate; (b) depositing a copper film and a magnesium film on the surface of the aluminum-silicon coated steel plate by using a magnetron sputtering coating technology to obtain an aluminum-silicon coated steel plate with the copper film and the magnesium film; and (c) heating the aluminum-silicon coating steel plate with the copper and magnesium films in a vacuum heating furnace, so that the coating and the surface film are fully diffused, and the aluminum-silicon-copper-magnesium coating steel plate with antibacterial property and corrosion resistance is prepared. According to the method, a Cu system is selected as a main antibacterial substance, and the Al-Si coated steel plate is subjected to a deposition and diffusion two-step method to prepare the composite coating. In addition, the Mg element is introduced to further improve the corrosion resistance of the material.

Description

Technical Field

[0001] The invention relates to an aluminum-silicon-copper-magnesium coated steel plate with antibacterial properties and enhanced corrosion resistance and a manufacturing method thereof, belonging to the field of hot-dip plating. Background Art

[0002] Aluminum-silicon coated steel sheet is an advanced steel material with excellent performance in high-temperature environments. It is produced by hot-dip coating the steel sheet with an aluminum-silicon alloy. This coating combines the high-temperature oxidation resistance of aluminum with the cathodic protection properties of zinc, enabling it to maintain stable corrosion resistance even under long-term use below 600°C, significantly surpassing the heat resistance of traditional galvanized steel sheet. Its unique microstructure also effectively inhibits the formation of brittle iron-aluminum phases, improving the material's processing and forming capabilities. This type of material is widely used in automotive exhaust systems, industrial furnaces, heat-resistant components of household appliances, and fire-resistant building structures, and is particularly suitable for applications requiring a balance between high-temperature strength and corrosion resistance. With tightening environmental regulations and growing demand for lightweighting, aluminum-silicon coated steel sheet is gradually replacing some stainless steel and aluminum-coated steel sheet, becoming a key material in the high-end manufacturing industry, and its market penetration is expected to continue to rise.

[0003] In pursuit of health, products with “antibacterial properties” are more popular among consumers. Therefore, it is necessary to prepare an aluminum-silicon-copper-magnesium element-coated steel plate with antibacterial properties and corrosion resistance. Summary of the Invention

[0004] To address the challenges of the prior art, the present invention provides an aluminum-silicon-copper-magnesium coated steel sheet with antibacterial and corrosion-resistant properties and a method for manufacturing the same. This invention utilizes a Cu-based compound as the primary antibacterial agent and utilizes a high-temperature diffusion mechanism to produce the composite coating on the Al-Si coated steel sheet through a two-step "deposition + diffusion" process under high-temperature conditions. Furthermore, the addition of Mg further enhances the material's corrosion resistance.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A method for preparing an aluminum-silicon-copper-magnesium coated steel plate having antibacterial properties and corrosion resistance, the manufacturing method comprising the following steps:

[0007] (a) A cold-rolled substrate is subjected to alkali washing and electrolytic degreasing treatment, continuous annealing, hot-dip plating, air knife purging, and post-plating cooling steps to form an aluminum-silicon (Al-Si) coated steel sheet;

[0008] (b) depositing a Cu thin film and a Mg thin film on the surface of an aluminum-silicon (Al-Si) coated steel plate using a magnetron sputtering coating technique, wherein the deposition order of the Cu thin film and the Mg thin film is not specifically required, thereby obtaining an aluminum-silicon (Al-Si) coated steel plate with Cu and Mg thin films;

[0009] (c) An aluminum-silicon (Al-Si) coated steel plate with Cu and Mg thin films is placed in a vacuum heating furnace for heating to allow sufficient diffusion of the coating and the surface film, thereby producing an aluminum-silicon-copper-magnesium (Al-Si-Cu-Mg) coated steel plate with antibacterial properties and corrosion resistance.

[0010] Furthermore, in step (a), the chemical composition of the cold-rolled substrate is calculated by mass percentage as follows: C: 0.006-1.1%, Si: 0.03-2.0%, Mn: 0.25-2.5%, S: ≤0.15%, P: ≤0.25%, Al: 0.006-0.21%, B≤0.15%, Nb: ≤0.15%, V: ≤0.15%, Ti: ≤0.15%, Cr: ≤0.6%, Ni: ≤0.6%, Mo: ≤0.6%, and the balance (Bal.) is Fe and unavoidable impurities (referred to as Fe).

[0011] Furthermore, in step (a), the thickness of the cold-rolled substrate is 0.3-2.5 mm.

[0012] Furthermore, in step (a), during the alkaline washing and degreasing process, the alkaline solution used is a NaOH solution or a KOH solution, the mass concentration of the alkaline solution is 2-7%, and the temperature of the alkaline solution is 65-90°C.

[0013] Furthermore, in step (a), during the electrolytic degreasing process, the current value ranges from 1A to 15A.

[0014] Furthermore, in step (a), during the continuous annealing process, the annealing temperature is 7000-880° C. and the strip speed is 30-150 m / min.

[0015] Furthermore, in step (a), the plating solution used in the hot-dip plating is prepared by melting Al-Si-Fe alloy ingots of a predetermined ratio to form an alloy plating solution.

[0016] Furthermore, the components of the alloy ingot with a predetermined ratio are calculated as follows by mass percentage: Si: 5-15 wt.%, Fe: 1-5 wt.%, and the balance is Al and unavoidable impurities (abbreviated as Al).

[0017] Furthermore, in step (a), during the hot dip coating process, the hot dip coating temperature is controlled to be 650-680°C, and the hot dip coating time is controlled to be 2.5-5s, wherein the temperature of the steel strip entering the pot is 5-10°C higher than the hot dip coating temperature.

[0018] Furthermore, in step (a), during the air knife blowing process, the air knife distance is 10-35 mm, the air knife pressure is 100-200 mbar, and by controlling the air knife blowing parameters, the thickness of the Al-Si coating after cooling is 10-40 μm.

[0019] Furthermore, in step (a), the temperature is cooled to 15-35° C. during the cooling process after plating.

[0020] Furthermore, in step (b), the deposition order of the Cu film and the Mg film is: first depositing the Cu film and then depositing the Mg film; or first depositing the Mg film and then depositing the Cu film.

[0021] Furthermore, in step (b), during the magnetron sputtering process, the sputtering current is 0.25-0.85A, the temperature of the aluminum-silicon coated steel plate is 100-350°C, and the sputtering power is 50-200W.

[0022] Furthermore, in step (b), the thickness of the Cu film and the thickness of the Mg film on the surface of the Al-Si coated steel plate are controlled to be 1-6 μm and 1-6 μm respectively.

[0023] Furthermore, in step (b), during the vacuum high-temperature diffusion process, the heating temperature is controlled at 500-600° C., the heating time is controlled at 1-6 minutes, and the coating is a mixture of Al, Si, Cu, and Mg.

[0024] The aluminum-silicon-copper-magnesium coated steel plate with antibacterial properties and corrosion resistance manufactured by the above manufacturing method comprises a steel plate substrate and an aluminum-silicon-copper-magnesium coating on the surface of the steel plate substrate.

[0025] Beneficial effects of the present invention:

[0026] (1) The present invention provides an antibacterial and corrosion-resistant aluminum-silicon-copper-magnesium coated steel plate and a method for manufacturing the same. The composite coating is produced through a two-step process of pre-coating and diffusion annealing. The element distribution and microstructure of the coating are regulated to impart antibacterial properties to the resulting steel plate. Furthermore, the element Mg is introduced to further enhance the corrosion resistance of the steel plate.

[0027] (2) Based on the development concept of Al-Si coated steel plates, the present invention innovatively combines "antibacterial" with Al-Si coated steel plates, and uses the diffusion mechanism to give the material surface a functional effect, so that the Al-Si coated steel plates have both high temperature resistance and antibacterial properties.

[0028] (3) This invention takes an inorganic antibacterial approach and, considering personal safety, selects Cu as the primary antibacterial agent, which possesses strong bactericidal properties. Its antibacterial mechanism is that metal ions can destroy bacterial structures or enter cells and bind to proliferative enzymes, inactivating them and thus achieving an antibacterial effect.

[0029] (4) The antibacterial (Staphylococcus aureus, Escherichia coli) rate of the aluminum-silicon-copper-magnesium coated steel plate provided by the present invention can reach 80-95%, and its corrosion resistance can reach red rust after 4000-5000 hours under neutral salt spray conditions according to GB / T10125-2021 "Artificial Atmosphere Corrosion Test Salt Spray Test". BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a mechanism diagram of the preparation process of the aluminum-silicon-copper-magnesium coated steel plate of the present invention. DETAILED DESCRIPTION

[0031] The following non-limiting examples may enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0032] Examples 1-5

[0033] A method for manufacturing an aluminum-silicon-copper-magnesium coated steel plate having antibacterial properties and corrosion resistance, comprising the following steps:

[0034] (a) melting an Al-Si-Fe alloy ingot of a predetermined ratio to prepare an alloy plating solution; wherein the composition of each element in the alloy plating solution is shown in Table 1;

[0035] (b) The cold-rolled substrate was subjected to alkali washing and electrolytic degreasing treatment, continuous annealing treatment, hot-dip plating, air knife purging, and post-plating cooling to form an Al-Si coated steel sheet; wherein, the alkali solution used in the alkali washing and degreasing process was a NaOH solution; the composition of the cold-rolled substrate is shown in Table 2, and the thickness is shown in Table 5; the preparation process parameters of the Al-Si coated steel sheet are shown in Table 3, and the substrate was cooled to room temperature after plating; the thickness of the Al-Si coating is shown in Table 5;

[0036] (c) Using magnetron sputtering technology to deposit Cu thin films and Mg thin films on the surface of the Al-Si coated steel plate, an Al-Si coated steel plate with Cu and Mg thin films is obtained; wherein the magnetron sputtering process parameters are shown in Table 4, and the thicknesses of the Cu and Mg films are shown in Table 5;

[0037] (d) The Al-Si coated steel plate with Cu and Mg thin films was placed in a vacuum heating furnace for heating to allow sufficient diffusion between the coating and the surface film, thereby producing an Al-Si-Cu-Mg coated steel plate with antibacterial properties and corrosion resistance; the parameters controlled during the vacuum high-temperature diffusion process are shown in Table 6.

[0038] Table 1 Proportion of each element in the alloy plating solution (mass ratio wt.%)

[0039] 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

[0040] Table 2 Chemical composition of cold-rolled substrate (wt.%)

[0041] C Si Mn S P Al B Nb V Ti Cr Ni Mo Fe. Example 1 0.24 0.25 1.8 0.03 0.02 0.03 0.02 - 0.04 - 0.07 - - Bal. Example 2 0.14 0.87 1.3 0.04 0.07 0.08 0.07 0.04 - 0.07 - 0.2 - Bal. Example 3 0.18 1.3 1.0 0.05 0.06 0.13 0.04 - - 0.06 - 0.06 Bal. Example 4 0.45 1.4 2.2 0.01 0.08 0.15 - - 0.02 - 0.03 - - Bal. Example 5 0.38 0.5 1.4 0.03 0.05 0.06 0.06 - 0.01 - 0.4 0.02 Bal.

[0042] Table 3 Preparation process parameters of Al-Si coated steel plates

[0043]

[0044] Table 4 Magnetron sputtering process parameters

[0045]

[0046] Table 5 Cold rolled substrate thickness, Al-Si coating thickness, Cu film thickness, Mg film thickness

[0047]

[0048]

[0049] Table 6 Parameter control of vacuum high temperature diffusion process

[0050] Heating temperature / ℃ Heating time / min Example 1 546 2 Example 2 572 4 Example 3 558 3.5 Example 4 569 2.5 Example 5 553 3

Claims

1. A method for manufacturing an aluminum-silicon-copper-magnesium coated steel plate having antibacterial properties and corrosion resistance, characterized in that: The following steps are involved: (a) a cold-rolled substrate is subjected to alkali washing and electrolytic degreasing, continuous annealing, hot-dip plating, air knife purging, and post-plating cooling to form an aluminum-silicon coated steel sheet; (b) depositing a copper film and a magnesium film on the surface of the aluminum-silicon coated steel plate using a magnetron sputtering coating technique to obtain an aluminum-silicon coated steel plate with copper and magnesium films; (c) The aluminum-silicon coated steel plate with copper and magnesium films is placed in a vacuum heating furnace for heating to allow the coating and the surface film to fully diffuse, thereby producing an aluminum-silicon-copper-magnesium coated steel plate with antibacterial properties and corrosion resistance.

2. The manufacturing method according to claim 1, characterized in that In step (a), the chemical composition of the cold-rolled substrate is as follows by mass percentage: C: 0.006-1.1%, Si: 0.03-2.0%, Mn: 0.25-2.5%, S: ≤0.15%, P: ≤0.25%, Al: 0.006-0.21%, B: ≤0.15%, Nb: ≤0.15%, V: ≤0.15%, Ti: ≤0.15%, Cr: ≤0.6%, Ni: ≤0.6%, Mo: ≤0.6%, and the balance is Fe and unavoidable impurities; the thickness of the cold-rolled substrate is 0.3-2.5 mm.

3. The manufacturing method according to claim 1, characterized in that In step (a), during the alkaline degreasing process, the alkaline solution used is a NaOH solution or a KOH solution, the mass concentration of the alkaline solution is 3-7%, and the temperature of the alkaline solution is 65-90° C.; during the electrolytic degreasing process, the current value is 1A-15A.

4. The manufacturing method according to claim 1, characterized in that In step (a), during the continuous annealing process, the annealing temperature is 700-880° C. and the strip speed is 30-150 m / min; During the hot-dip plating process, the plating solution used is an alloy plating solution prepared by melting an Al-Si-Fe alloy ingot; wherein the composition of the alloy ingot is as follows by mass percentage: Si: 5-15%, Fe: 1-5%, and the balance is Al and inevitable impurities.

5. The manufacturing method according to claim 1, characterized in that In step (a), during the hot dip coating process, the hot dip coating temperature is controlled to be 640-680° C., the hot dip coating time is 2.5-5 seconds, and the temperature of the steel strip entering the pot is 5-10° C. higher than the hot dip coating temperature; During the air knife blowing process, the air knife distance is 10-35mm and the air knife pressure is 100-200mbar. By controlling the air knife blowing parameters, the thickness of the aluminum silicon coating after cooling is 10-35μm. Cool to 15-35℃ during the post-plating cooling process.

6. The manufacturing method according to claim 1, characterized in that In step (b), the deposition order of the copper film and the magnesium film is: first depositing the copper film and then depositing the magnesium film; or first depositing the magnesium film and then depositing the copper film.

7. The manufacturing method according to claim 1, characterized in that In step (b), during the magnetron sputtering process, the sputtering current is 0.25-0.85A, the temperature of the aluminum-silicon coated steel plate is 100-350°C, and the sputtering power is 40-200W.

8. The manufacturing method according to claim 1, characterized in that In step (b), the thickness of the copper film on the surface of the aluminum-silicon coated steel plate is controlled to be 1-6 μm, and the thickness of the magnesium film is controlled to be 1-6 μm.

9. The manufacturing method according to claim 1, characterized in that In step (c), the heating temperature is controlled at 500-600° C. and the heating time is controlled at 1-6 minutes.

10. The antibacterial and corrosion-resistant aluminum-silicon-copper-magnesium coated steel plate manufactured by the manufacturing method according to any one of claims 1 to 9, characterized in that: The aluminum-silicon-copper-magnesium coated steel plate comprises a steel plate substrate and an aluminum-silicon-copper-magnesium coating on the surface of the steel plate substrate.

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