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

Abstract

The invention discloses an aluminum silicon-zinc 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 zinc 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 zinc film and the magnesium film; and (c) heating the aluminum-silicon coating steel plate with the zinc and magnesium films in a vacuum heating furnace, so that the coating and the surface film are fully diffused, and the aluminum-silicon-zinc magnesium coating steel plate with antibacterial property and corrosion resistance is prepared. The composite coating is prepared through a two-step method of coating prefabrication and diffusion annealing, element distribution and an organization structure in the coating are regulated and controlled, the obtained steel plate has the antibacterial performance, and the corrosion resistance of the steel plate is improved.

Description

Technical Field

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

[0002] Al-Si coating technology was first developed and patented by Arcelor Mittal. Al-Si was originally designed to prevent oxidation and decarburization of automotive parts during the hot stamping process. Today, Al-Si coated steel sheets are no longer limited to the automotive sector. Due to their excellent high-temperature and corrosion resistance, Al-Si coated steel sheets have also begun to be used in the home appliance field, such as some steam ovens, heating furnaces and other household appliances used in high-temperature environments. Studies have shown that Al-Si coated steel sheets can maintain a bright appearance at temperatures below 450°C. However, as the operating environment becomes more demanding, its corrosion resistance is challenged and needs to be further enhanced.

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

[0004] To address the problems of the prior art, the present invention provides an aluminum-silicon-zinc-magnesium-coated steel sheet with antibacterial and corrosion-resistant properties and a method for manufacturing the same. This invention utilizes Zn as the primary antibacterial agent and utilizes a high-temperature diffusion mechanism to produce the composite coating through a two-step "deposition + diffusion" process on the Al-Si-coated steel sheet. Furthermore, Mg is added to enhance corrosion resistance.

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

[0006] A method for preparing an aluminum-silicon-zinc-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 Zn film and a Mg 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 Zn and Mg films is not specifically required, thereby obtaining an Al-Si coated steel plate with Zn and Mg films;

[0009] (c) An aluminum-silicon (Al-Si) coated steel plate with Zn 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-zinc-magnesium (Al-Si-Zn-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: 0.004-1.1%, Si: 0.03-2.1%, Mn: 0.22-2.6%, S: ≤0.15%, P: ≤0.25%, Al: 0.005-0.2%, 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 concentration of the alkaline solution is 3-7%, and the temperature of the alkaline solution is 70-85°C.

[0013] Furthermore, in step (a), during the electrolytic degreasing process, the current value ranges from 1A to 14A.

[0014] Furthermore, in step (a), during the continuous annealing process, the annealing temperature is 680-870° C. and the strip speed is 30-160 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 640-685°C, and the hot dip coating time is controlled to be 3-6s, 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 controlled to be 10-30 mm, and the air knife pressure is controlled to be 100-200 mbar. By controlling the air knife blowing parameters, the thickness of the Al-Si coating after cooling is made to be 9-35 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), during the magnetron sputtering process, the sputtering current is 0.15-0.8A, the temperature of the aluminum-silicon coated steel plate is 90-300°C, and the sputtering power is 60-200W.

[0021] Furthermore, in step (b), the deposition order of the Zn film and the Mg film is: first depositing the Zn film and then depositing the Mg film; or first depositing the Mg film and then depositing the Zn film.

[0022] Furthermore, in step (b), the thickness of the Zn film and the thickness of the Mg film on the surface of the Al-Si coated steel plate are controlled to be 1-5 μm and 1-5 μm respectively.

[0023] Furthermore, in step (c), during the vacuum high-temperature diffusion process, the heating temperature is controlled at 400-600°C, the heating time is controlled at 1-6 minutes, and the coating is a mixture of Al, Si, Zn, Mg, and MgZn2.

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

[0025] Beneficial effects of the present invention:

[0026] (1) The present invention provides an aluminum-silicon-zinc-magnesium coated steel plate with antibacterial and corrosion resistance and a method for manufacturing the same. A composite coating is prepared by a "two-step method" of pre-coating and diffusion annealing, and the element distribution and organizational structure in the coating are regulated so that the obtained steel plate has antibacterial properties and increased corrosion resistance.

[0027] (2) The present invention combines "antibacterial" with Al-Si coated steel plates, and uses a diffusion mechanism to make the Al-Si coated steel plates have both high temperature resistance and antibacterial properties.

[0028] (3) The present invention is based on an inorganic antibacterial mechanism and selects Zn-based metal ions with higher safety as the core antibacterial component. Zn2+ achieves efficient sterilization through a dual mechanism of action: on the one hand, it directly destroys the bacterial cell membrane structure; on the other hand, it penetrates into the interior of the bacteria and combines with metabolic enzymes to inactivate them, thereby inhibiting bacterial reproduction. In order to further improve the performance of the material, the Mg element is specially introduced, and its active protective effect is used to enhance the overall corrosion resistance, thereby improving the durability of the material while ensuring the antibacterial effect. This system has both biosafety and long-lasting antibacterial properties, and is suitable for medical, household and other health protection fields.

[0029] (4) The antibacterial (Staphylococcus aureus, Escherichia coli) rate of the aluminum-silicon-copper-zinc coating prepared by the present invention can reach 70-90%; its corrosion resistance can reach red rust after 3000-5000 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-zinc-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-zinc-magnesium coated steel plate having antibacterial properties and corrosion resistance, comprising the following specific 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, continuous annealing, 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 steel sheet 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, a Zn film and a Mg film are sequentially deposited on the surface of the Al-Si coated steel plate to obtain an Al-Si coated steel plate with Zn and Mg films; wherein the magnetron sputtering process parameters are shown in Table 4, and the Zn film thickness is shown in Table 5;

[0037] (d) The Al-Si coated steel plate with Zn 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 vacuum high-temperature diffusion process parameter control is shown in Table 6.

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

[0039]

[0040]

[0041] Table 2 Chemical composition of cold-rolled substrate (wt.%)

[0042] C Si Mn S P Al B Nb V Ti Cr Ni Mo Fe. Example 1 0.45 1.4 2.2 0.01 0.08 0.15 - - 0.02 - 0.03 - Bal. Example 2 0.38 0.5 1.4 0.01 0.05 0.06 0.06 - - 0.01 - 0.3 0.01 Bal. Example 3 0.24 0.26 1.6 0.03 0.03 0.03 0.03 - 0.04 - 0.05 - - Bal. Example 4 0.14 0.85 1.3 0.04 0.06 0.08 0.05 0.04 - 0.06 - 0.2 - Bal. Example 5 0.18 1.3 1.0 0.04 0.08 0.13 0.03 - - 0.03 - - 0.05 Bal.

[0043] Table 3 Preparation process parameters of Al-Si coated steel plates

[0044]

[0045] Table 4 Magnetron sputtering process parameters

[0046]

[0047] Table 5 Cold rolled substrate thickness, Al-Si coating thickness, Zn film thickness, Mg film thickness

[0048] Cold rolled substrate / mm Al-Si coating / μm Zn thin film / μm Mg film / μm Example 1 0.45 13 2 5 Example 2 1.3 28 3 3 Example 3 0.8 24 1 1 Example 4 0.85 22 5 2 Example 5 1.4 15 5 4

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

[0050] Heating temperature / ℃ Heating time / min Example 1 521 2 Example 2 472 4 Example 3 483 3.5 Example 4 510 2.5 Example 5 530 3.5

Claims

1. A method for manufacturing an aluminum-silicon-zinc-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 zinc 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 zinc and magnesium films; (c) The aluminum-silicon coated steel plate with zinc and magnesium films is placed in a vacuum heating furnace for heating to allow the coating and the surface film to fully diffuse, thereby obtaining an aluminum-silicon-zinc-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: 0.004-1.1%, Si: 0.03-2.1%, Mn: 0.22-2.6%, S: ≤0.15%, P: ≤0.25%, Al: 0.005-0.2%, B ≤0.15%, Nb: ≤0.15%, V: ≤0.15%, Ti: ≤0.15%, Cr: ≤0.6%, Ni: ≤0.6%, Mo: ≤0.6%; 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 70-85° C.; during the electrolytic degreasing process, the current value is 1A-14A.

4. The manufacturing method according to claim 1, characterized in that In step (a), during the continuous annealing process, the annealing temperature is 680-870° C. and the strip speed is 30-160 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 640-685° C., the hot dip coating time is 3-6 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 10-30mm 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 9-35μm. 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 order of depositing the zinc film and the magnesium film is: depositing the zinc film first and then depositing the magnesium film; or depositing the magnesium film first and then depositing the zinc film.

7. The manufacturing method according to claim 1, characterized in that In step (b), during the magnetron sputtering process, the sputtering current is 0.15-0.8A, the temperature of the aluminum-silicon coated steel plate is 90-300°C, and the sputtering power is 60-200W.

8. The manufacturing method according to claim 1, characterized in that In step (b), the thickness of the zinc film on the surface of the aluminum-silicon coated steel plate is controlled to be 1-5 μm, and the thickness of the magnesium film is controlled to be 1-5 μm.

9. The manufacturing method according to claim 1, characterized in that In step (c), the heating temperature is controlled at 400-600° C. and the heating time is controlled at 1-6 minutes.

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

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