Stainless steel with high antibacterial property and preparation method thereof

Abstract

The invention relates to high-antibacterial-property stainless steel and a preparation method thereof, and relates to the field of metal materials and preparation thereof, and the high-antibacterial-property stainless steel comprises the following components in parts by weight: 18-20 parts of chromium, 8-10 parts of nickel, 0.05-0.15 part of carbon, 0.3-0.5 part of silicon, 1-1.8 parts of manganese, 68-75 parts of iron and 0.1-0.3 part of an antibacterial-property component. The antibacterial component comprises silver acetylacetonate. The silver acetylacetonate is used as an antibacterial component, nano-scale uniform dispersion of silver elements in a stainless steel matrix is achieved through the stable thermal decomposition characteristic of the silver acetylacetonate and the wrapping effect of organic ligands, a stable silver dispersion phase is formed, the durability of the antibacterial effect is improved, and reliable basic antibacterial capacity is provided for stainless steel.

Description

Technical Field

[0001] This application relates to the field of metallic materials and their preparation, specifically to a high antibacterial stainless steel and its preparation method. Background Technology

[0002] Stainless steel, as an important metallic material, has a wide range of applications in modern industry and daily life. With the rapid development of industry, stainless steel, with its excellent corrosion resistance, high strength, and aesthetics, plays a key role in many fields such as construction, machinery manufacturing, food processing, and medical equipment.

[0003] In preparing stainless steel with antibacterial properties, existing technologies typically employ the following methods: (1) Coating the stainless steel surface with an antibacterial coating, and adding antibacterial agents, such as silver ions and copper ions, to the coating to give the stainless steel surface antibacterial function. This method can achieve antibacterial effect without changing the composition of the stainless steel matrix, and the operation is relatively simple. (2) Introducing antibacterial elements into the stainless steel surface through surface treatment technologies, such as ion implantation and chemical plating, to form a surface layer with antibacterial properties. (3) Adding some alloying elements with antibacterial effects, such as copper and silver, during the stainless steel smelting process to give the stainless steel overall antibacterial properties.

[0004] However, surface-coated antibacterial coatings are prone to wear and peeling during use, leading to a decrease in antibacterial performance, and the coating's adhesion and stability are limited. While surface treatment technology can improve surface antibacterial properties, both surface treatment and antibacterial coating treatments are relatively shallow, making it difficult to guarantee good antibacterial properties within the stainless steel itself. Furthermore, when antibacterial alloying elements are added during the smelting process, the low solubility of these elements in the iron-based solid solution makes them prone to segregation during smelting and cooling, forming coarse second-phase particles. This hinders the uniform distribution of antibacterial elements, reducing the broad-spectrum and stable antibacterial effect of the stainless steel. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a high-antibacterial stainless steel and its preparation method. In a first aspect, this application provides a high-antibacterial stainless steel, employing the following technical solution: A highly antibacterial stainless steel comprises the following components in parts by weight: 18 parts chromium, 8-10 parts nickel, 0.05-0.15 parts carbon, 0.3-0.5 parts silicon, 1-1.8 parts manganese and 68-75 parts iron, and 0.1-0.5 parts antibacterial component; said antibacterial component includes silver acetylacetone.

[0006] By adopting the above technical solution, silver acetylacetone can stably decompose and release silver atoms. The organic ligand can "encapsulate" the silver atoms released in the early stage, reducing the possibility of silver atoms agglomerating into coarse particles due to high temperature. Finally, a nanoscale silver dispersion phase is formed in the matrix, achieving uniform distribution of silver elements and long-lasting antibacterial effect.

[0007] This application incorporates silver in the form of a compound, thereby reducing the initial activity of silver and mitigating the problems of elemental silver being easily oxidized due to its high activity and easily agglomerated due to its low solid solubility. At the same time, it lays the foundation for the uniform dispersion of silver during the high-temperature treatment process and significantly reduces the phenomenon of local enrichment of silver.

[0008] Preferably, the antibacterial component further includes at least one of copper nitrate and zinc sulfate.

[0009] By adopting the above technical solution, after high-temperature treatment, the antibacterial components form nanoscale silver, copper oxide, or zinc oxide dispersion phases in the stainless steel matrix. When the stainless steel comes into contact with microorganisms, the antibacterial dispersion phase can slowly release silver ions, copper ions, or zinc ions. Copper ions can target and inhibit the activity of key enzymes in microorganisms, while zinc ions can destroy the integrity of microbial cell membranes and interfere with their metabolic cycles. Both can form a synergistic antibacterial system with silver ions, broaden the antibacterial spectrum of the antibacterial components, and improve the stability of antibacterial efficacy.

[0010] Preferably, the antibacterial component is a mixture of silver acetylacetone and copper nitrate.

[0011] By adopting the above technical solution, the decomposition temperature range of copper nitrate is closer to that of silver acetylacetone, and the two can complete thermal decomposition simultaneously, achieving a uniform distribution of elemental silver and copper oxide dispersed phases, reducing the risk of premature or delayed decomposition of a single component to form coarse particles; moreover, the decomposition products of copper nitrate are copper oxide and nitrogen oxides, and nitrogen oxides can be discharged during sintering without residual impurities, while zinc sulfate decomposition may leave a small amount of sulfate impurities, so copper nitrate is preferred.

[0012] Preferably, the mass ratio of silver acetylacetone to copper nitrate is 1:(1.8-2.2).

[0013] By adopting the above technical solution, when the mass ratio is too low, the copper oxide content is insufficient, making it difficult to fully exert the synergistic antibacterial effect with elemental silver, and the improvement in antibacterial efficacy is limited; when the mass ratio is too high, the silver content is relatively insufficient, making it equally difficult to fully exert the synergistic antibacterial effect with copper oxide. Therefore, after extensive research and experimental verification, the applicant has determined that the mass ratio of silver acetylacetone and copper nitrate in this application is as described above.

[0014] Secondly, this application provides a method for preparing highly antibacterial stainless steel, employing the following technical solution: A method for preparing highly antibacterial stainless steel, comprising the following steps: S1. Mix the formulated amounts of chromium, nickel, carbon, silicon, manganese and iron with the antibacterial components, add grinding aid and wetting agent, ball mill, and dry to obtain antibacterial alloy composite powder; S2. The antibacterial alloy composite powder is subjected to pressing, sintering, solution treatment and aging treatment in sequence to obtain the high antibacterial stainless steel.

[0015] Preferably, in S1, the grinding aid is talc.

[0016] By adopting the above technical solution, talc can effectively reduce the internal friction and adhesion between alloy powder particles during ball milling, reduce particle agglomeration, and achieve a good grinding aid effect. Simultaneously, talc has excellent thermal stability and can stably decompose into magnesium oxide and silicon dioxide in the high-temperature process of stainless steel processing. Magnesium oxide possesses auxiliary antibacterial properties, inhibiting microbial growth by adjusting the pH of the local microenvironment. It also works synergistically with antibacterial particles such as elemental silver and copper oxide to further enhance the antibacterial efficacy of the material.

[0017] In addition, during the ball milling process, talc powder is refined and uniformly dispersed in the composite powder under the action of mechanical force. The specific surface area of ​​the refined talc powder particles is significantly increased, which can effectively adsorb the antibacterial particles generated by the thermal decomposition of antibacterial components, reduce the probability of antibacterial particle migration and agglomeration, assist the antibacterial components to achieve uniform dispersion distribution in the alloy matrix, and delay the excessive diffusion of antibacterial particles, thus prolonging the antibacterial effect.

[0018] Preferably, the sintering process in S2 includes a pre-decomposition stage: heating to 350-400℃ at a rate of 2-5℃ / min.

[0019] By adopting the above technical solution, slow heating can effectively avoid the violent decomposition of antibacterial components or the rapid removal of structural water from talc powder, which would generate a large amount of gas. At the same time, it removes the trace amounts of moisture and volatile impurities adsorbed in the antibacterial alloy composite powder, reduces the possibility of pores or cracks forming inside the blank, and ensures the compactness of the powder particles.

[0020] Furthermore, the structural water released by talc at this temperature can form a vapor film on the surface of the antibacterial alloy composite powder particles, effectively reducing the friction between particles and promoting the contact and bonding of the antibacterial alloy composite powder particles. When the vapor film ruptures, the powder particles undergo plastic deformation, which in turn promotes the formation of sintering necks and lays the foundation for improving the density of the stainless steel sintered body.

[0021] Preferably, the sintering process in S2 further includes: First stage: Increase the temperature by 5-10℃ / min to 550-650℃; Second stage: Increase the temperature by 10-15℃ / min to 1150-1250℃.

[0022] By adopting the above technical solution, although most of the decomposition is completed in the pre-decomposition stage, the residual components need to be completely decomposed in a mild heating environment. The temperature and heating rate of the first stage can avoid defects in the antibacterial phase caused by residual antibacterial components or incomplete decomposition. At the same time, this temperature range can match the activation process of talc powder after destructive water removal, further increasing the specific surface area of ​​talc powder, thereby more efficiently adsorbing incompletely diffused antibacterial particles, laying a solid foundation for the uniform dispersion distribution of the antibacterial phase.

[0023] The second stage raises the temperature to the sintering core temperature at a faster rate, which can reduce the loss of antibacterial particles at high temperatures and improve the stability of the antibacterial component content. It can also enable the magnesium oxide and silicon dioxide produced by the decomposition of talc to quickly fuse with the matrix, avoiding their excessive aggregation and formation of impurity phases. At the same time, with the fine grain control, the antibacterial phase is uniformly embedded in the grain boundaries and within the grains, forming a synergistic structure of fine grain matrix and dispersed antibacterial phase.

[0024] Preferably, the solution treatment temperature in S2 is 1050-1150℃, and the holding time is 60-90min.

[0025] By adopting the above technical solution, it is possible to fully dissolve matrix alloying elements such as chromium and nickel in iron-based solid solution to form a uniform and stable austenitic structure. If the temperature is too high, the antibacterial phase generated by the decomposition of antibacterial components may be lost. If the temperature is too low, the antibacterial phase and talc decomposition products may not diffuse fully, resulting in the aggregation or uneven distribution of the antibacterial phase.

[0026] Insufficient heat preservation time will lead to uneven distribution of alloying elements in the solid solution, making it difficult for antibacterial particles to form a continuous and diffuse distribution, thus reducing the uniformity of antibacterial performance. Excessive heat preservation time will cause excessive growth of austenite grains, reduce the mechanical properties of stainless steel, and even cause excessive diffusion and aggregation of antibacterial particles to form coarse antibacterial phase particles, weakening the antibacterial efficacy and long-term effect.

[0027] Furthermore, by promoting the full solid solution and uniform distribution of chromium, a dense chromium oxide film can be rapidly formed on the substrate surface during the subsequent cooling process. The dispersed magnesium oxide and silicon dioxide particles can further fill the defects in the oxide film, improve the integrity and stability of the oxide film, and achieve a synergistic improvement in antibacterial properties and corrosion resistance, laying a good foundation for the subsequent precipitation of more stable antibacterial phases.

[0028] Preferably, the aging process in S2 includes: Phase 1: Incubate at 450-500℃ for 1-2 hours; Second stage: Keep warm at 500-550℃ for 1-2 hours.

[0029] By adopting the above technical solution In the first stage, low-temperature induction leads to uniform nucleation of the antibacterial phase. Magnesium oxide and silicon dioxide nanoparticles produced by the decomposition of talc can serve as heterogeneous nucleation cores. Their high specific surface area and surface active sites can adsorb surrounding antibacterial particles, promoting the preferential nucleation of the antibacterial phase on its surface and forming a large number of uniformly sized fine crystal nuclei. The low-temperature environment can slowly release the residual internal stress after the solid solution treatment, reducing the possibility of microcracks caused by internal stress concentration in the subsequent high-temperature aging stage and improving the structural integrity of the material.

[0030] The second stage involves the orderly growth of the antibacterial phase under medium temperature regulation. By moderately increasing the temperature, the diffusion rate of antibacterial ions is accelerated, which promotes the slow growth of small crystal nuclei and forms a synergistic diffused antibacterial network in which the intracrystalline antibacterial phase releases antibacterial ions for a long time and the crystal boundary antibacterial phase blocks the attachment and reproduction of microorganisms at the interface.

[0031] In summary, this application has the following beneficial effects: This application uses silver acetylacetone as the antibacterial component. Through its stable thermal decomposition characteristics and the "encapsulation" effect of organic ligands, silver elements are uniformly dispersed at the nanoscale in the stainless steel matrix, forming a stable silver dispersion phase. This improves the durability of the antibacterial effect and provides a reliable basic antibacterial capability for stainless steel. This application significantly broadens the antibacterial spectrum and improves the stability of antibacterial efficacy by leveraging the synergistic effect of silver and copper elements, based on the antibacterial effect of silver acetylacetone. Furthermore, the synchronous thermal decomposition characteristics of both elements enable the uniform co-dispersion of the two antibacterial particles, effectively reducing the possibility of local antibacterial failure caused by asynchronous decomposition of different antibacterial components. This application uses talc as a grinding aid, which can effectively reduce powder agglomeration and improve the uniformity of antibacterial alloy composite powder. At the same time, the high specific surface area of ​​talc after ball milling can realize the secondary dispersion and adsorption fixation of the antibacterial phase, delaying the decay of antibacterial effect. In addition, the overall antibacterial ability can be enhanced by the auxiliary antibacterial effect of magnesium oxide produced by the high temperature decomposition of talc. This application reduces manufacturing defects such as porosity and cracks in the billet by segmented and precise temperature control, effectively improving the structural integrity of the finished stainless steel product. It can promote the uniform dispersion of the antibacterial phase and ensure the formation of a stable austenitic structure and a dense oxide film in stainless steel, ultimately achieving synergistic optimization of antibacterial properties, corrosion resistance and mechanical properties. Detailed Implementation

[0032] The raw materials in this application include the following: Silver acetylacetone: Uses a commercially available product with CAS number 15525-64-1; Wetting agent: Commercially available product using anhydrous ethanol with CAS number 64-17-5; Talc powder: Commercially available product with an average particle size of 3000 mesh, produced by Lingshou County Jushi Mineral Products Processing Plant; The present application will be further described in detail below with reference to embodiments and comparative examples.

[0033] Example 1 A method for preparing highly antibacterial stainless steel includes the following steps: S1a. Place 19 kg of chromium powder, 9 kg of nickel powder, 0.1 kg of carbon (graphite powder), 0.4 kg of silicon powder, 1.5 kg of manganese powder, 70 kg of iron powder, and 0.2 kg of silver acetylacetone into a three-dimensional mixer and premix at 200 r / min for 30 min to obtain a mixed dry material. S1b. Add the above mixed dry materials to the mixing tank of a planetary ball mill, add 0.5 kg of talc powder and 5 kg of anhydrous ethanol for ball milling, and use zirconia balls as the ball milling medium (ball-to-material ratio 10:1, ball diameter ratio 5 mm:3 mm:1 mm = 2:3:5). Set the ball milling parameters as follows: rotation speed 300 r / min, time 4 h, alternating between forward rotation for 30 min and reverse rotation for 30 min. During the ball milling process, the temperature of the ball mill tank is controlled to be below 50℃ by circulating water cooling to obtain the ball mill slurry. S1c. Transfer the ball-milled slurry into a vacuum drying oven, set the temperature to 60℃ and the vacuum degree to -0.09MPa, dry for 4 hours, and remove the grinding balls and large particle agglomerates through a 200-mesh standard sieve to obtain antibacterial alloy composite powder. S2a. The antibacterial alloy composite powder is loaded into a cylindrical mold with a diameter of 50mm and a diameter of 10mm, and pressed using a cold isostatic press with a pressing pressure of 200MPa and a holding time of 5min. After demolding, a green blank is obtained. S2b. Sintering was carried out in a box-type atmosphere sintering furnace. Argon gas was introduced at a flow rate of 0.5 L / min. The green billet was transferred into the sintering furnace for heating. In the pre-decomposition stage, the temperature was increased to 380℃ at a rate of 3℃ / min and held for 1 h. Then, the temperature was increased to 600℃ at a rate of 8℃ / min and held for 2 h. Then, in the second stage, the temperature was increased to 1200℃ at a rate of 12℃ / min and held for 3 h. Then, the temperature was cooled to 500℃ in the furnace and then cooled to room temperature at a rate of 10℃ / min to obtain the stainless steel sintered body. S2c. Place the stainless steel sintered body into a solution furnace, introduce argon gas at a flow rate of 0.3 L / min for protection, heat to 1100℃ at a rate of 15℃ / min, and hold for 75 min; then quickly remove it and immerse it in deionized water at 20℃ to cool, and obtain the solution product. S2d. After drying the solution product with hot air at 80℃ for 30 min, it was placed in an aging furnace and protected with argon gas at a flow rate of 0.2 L / min. The temperature was increased to 480℃ at 10℃ / min and held for 1.5 h. Then, the temperature was increased to 520℃ at 5℃ / min and held for 1.5 h. The furnace was then cooled to room temperature to obtain high antibacterial stainless steel.

[0034] Example 2-3 Examples 2-3 are based on the preparation method of Example 1, but the amount of raw materials for high antibacterial stainless steel is adjusted, as shown in Table 1.

[0035] Comparative Examples 1-2 Comparative Example 1 adjusts the amount of raw materials used in the high antibacterial stainless steel based on the preparation method of Example 1. The specific adjustments are shown in Table 1.

[0036] Comparative Example 2 was prepared using the same method as in Example 1, but with 0.2 kg of silver acetylacetone replaced by 0.15 kg of silver powder, while keeping all other conditions unchanged.

[0037] The high antibacterial stainless steels of Examples 1-3 and Comparative Examples 1-2 were subjected to the following performance tests, and the test results are shown in Table 1: (1) Antibacterial properties The antibacterial properties of high-antimicrobial stainless steel were tested using the coating method according to JIS Z2801-2000 standard. *Escherichia coli* (ATCC 25922) and *Staphylococcus aureus* (ATCC 25923) were used as test bacteria, and a concentration of 10 was prepared. 5 CFU / mL bacterial suspension was uniformly added dropwise to the surfaces of the highly antibacterial stainless steel prepared in the examples and comparative examples, with a bacterial suspension volume of 0.4 mL. Subsequently, a sterile polyethylene film was coated onto the highly antibacterial stainless steel surface, and the samples were incubated in a constant temperature incubator at 36±1℃ for 24 h. Viable bacteria were then counted. Comparative example 1 served as the control group, and the others as experimental groups. The antibacterial rate of the highly antibacterial stainless steel was calculated. Antibacterial rate = (number of viable bacteria) 对照组 - viable bacteria count 实验组 ) / Viable bacteria count 对照组 ×100%; The highly antibacterial stainless steel surface of the experimental group was placed in an aging test chamber and subjected to an aging test for 28 days at a temperature of 37±1℃ and a relative humidity of 90±5%. The above-mentioned coating method test steps were then repeated to calculate the long-term antibacterial rate of the antibacterial stainless steel. Long-lasting antibacterial rate = (number of viable bacteria) 对照组 - viable bacteria count 老化实验组 ) / Viable bacteria count 对照组 ×100%.

[0038] Table 1. Raw material list and performance test table for the high antibacterial stainless steel of Examples 1-3 and Comparative Examples 1-2.

[0039] Referring to Table 1, comparing Examples 1-3 and Comparative Examples 1-2, it can be seen that after adding silver acetylacetone as an antibacterial component to the stainless steel formulation, the antibacterial rate of the stainless steel material against Escherichia coli and Staphylococcus aureus reached over 99.08%, and the long-term antibacterial rate remained above 98.53%, which is better than Comparative Example 2, which directly added silver powder. This indicates that the organic ligand encapsulation effect of silver acetylacetone can effectively prevent the aggregation of silver elements and achieve uniform dispersion at the nanoscale, thereby improving the stability and durability of the antibacterial effect.

[0040] Examples 4-5 Example 4 is based on the preparation method of Example 1, but 0.2 kg of silver acetylacetone is replaced with 0.35 kg of a mixture of silver acetylacetone and copper nitrate, wherein the mass ratio of silver acetylacetone to copper nitrate is 1:2, and the other conditions remain unchanged.

[0041] Example 5 is based on the preparation method of Example 1, except that 0.2 kg of silver acetylacetone is replaced with 0.35 kg of a mixture of silver acetylacetone and zinc sulfate, wherein the mass ratio of silver acetylacetone to zinc sulfate is 1:2, and the other conditions remain unchanged.

[0042] The high antibacterial stainless steels of Examples 4-5 were subjected to the above performance tests, and the test results are shown in Table 2.

[0043] Table 2 Performance test table of high antibacterial stainless steel in Examples 1 and 4-5

[0044] Referring to Table 2, a comparison of Examples 1 and 4-5 shows that the introduction of copper nitrate or zinc sulfate into the antibacterial component improves both the antibacterial performance and long-lasting antibacterial properties of the material compared to the single silver acetylacetone system. This indicates that there is a synergistic antibacterial effect between silver, copper, and zinc, which can broaden the antibacterial spectrum and enhance the stability of antibacterial efficacy. Among them, the antibacterial effect of Example 4 is slightly better than that of Example 5. Therefore, copper nitrate is the preferred synergistic antibacterial component.

[0045] Examples 6-9 Examples 6-9 are based on the preparation method of Example 4, keeping the total mass of silver acetylacetone and zinc sulfate unchanged, and adjusting the mass ratio of silver acetylacetone and copper nitrate, as shown in Table 3.

[0046] The high antibacterial stainless steels of Examples 6-9 were subjected to the above performance tests, and the test results are shown in Table 3.

[0047] Table 3 Performance test table of high antibacterial stainless steel in Examples 4 and 6-9

[0048] Referring to Table 3, a comparison of Examples 4 and 6-9 shows that when the mass ratio of silver acetylacetone to copper nitrate is in the range of 1:(1.8-2.2), the antibacterial rate of stainless steel material against Escherichia coli and Staphylococcus aureus is stable at over 99.76% and over 99.82%, respectively, and the long-term antibacterial rate is over 99.61%. This indicates that when the mass ratio of silver acetylacetone to copper nitrate is within this range, the synergistic antibacterial effect of silver acetylacetone and copper nitrate reaches the optimal level.

[0049] Examples 10-13 Examples 10-13 are based on the preparation method of Example 1, but the parameters of the sintering treatment are adjusted, as shown in Table 4.

[0050] The high antibacterial stainless steels of Examples 1 and 10-13 were subjected to performance testing. The test results are shown in Table 4. (1) Tensile strength The tensile strength of high antibacterial stainless steel was tested according to the standard GB / T 228.1-2021.

[0051] (2) Corrosion resistance Weigh the initial mass M0 of the high antibacterial stainless steel and conduct a neutral salt spray test according to the standard GB / T 10125-2021. Spray a 5wt% NaCl solution onto the surface of the high antibacterial stainless steel in a constant temperature chamber at 36±1℃ for 120 h. After spraying, remove the stainless steel and weigh the mass M1 after the salt spray test. Calculate the weight loss rate W of the high antibacterial stainless steel before and after the neutral salt spray test. r : W r = (M0 - M1) / M0 × 100%.

[0052] Table 4. Sintering treatment parameters and performance test results for Examples 1 and 10-13

[0053] Referring to Table 4, a comparison of Examples 1 and 10-13 shows that when the sintering process parameters are: a pre-decomposition stage with a heating rate of 2-5℃ / min to 350-400℃, a first stage with a heating rate of 5-10℃ / min to 550-650℃, and a second stage with a heating rate of 10-15℃ / min to 1150-1250℃, the stainless steel material exhibits higher tensile strength, lower weight loss in the neutral salt spray test, and maintains a high level of antibacterial rate and long-term antibacterial rate. This is because sintering parameters within the above range can prevent the drastic decomposition of antibacterial components and the formation of pore cracks in the green body, while simultaneously promoting the uniform dispersion and densification of the antibacterial phase and the matrix, thereby improving the comprehensive performance of the high-antibacterial stainless steel.

[0054] Examples 14-17 Examples 14-17 are based on the preparation method of Example 1, with adjustments made to the parameters of the solution treatment. The specific adjustments are shown in Table 5.

[0055] The high antibacterial stainless steels of Examples 1 and 14-17 were subjected to the above performance tests, and the test results are shown in Table 5.

[0056] Table 5 Solution treatment parameters and performance test results for Examples 1 and 14-17

[0057] Referring to Table 5, comparing Example 1 and Examples 14-17, it can be seen that when the solution temperature is 1050-1150℃ and the holding time is 60-90min, the overall performance of stainless steel is better. This is because suitable solution parameters can promote the full dissolution of the matrix alloying elements and promote the uniform diffusion of the antibacterial phase, forming a stable austenitic structure and a dense oxide film.

[0058] Examples 18-21 Examples 18-21 are based on the preparation method of Example 1, with adjustments made to the parameters of the aging treatment. The specific adjustments are shown in Table 6.

[0059] The high antibacterial stainless steels of Examples 1 and 18-21 were subjected to the above performance tests, and the test results are shown in Table 6.

[0060] Table 6. Aging treatment parameters and performance test results for Examples 1 and 18-21

[0061] Referring to Table 6, a comparison of Examples 1 and 18-21 shows that the comprehensive performance of the high antibacterial stainless steel material is optimal when the aging treatment parameters are a two-stage process with a first-stage temperature of 450-500℃ for 1-2 hours and a second-stage temperature of 500-550℃ for 1-2 hours. This is because the above aging treatment parameters can achieve uniform nucleation and orderly growth of the antibacterial phase, forming a diffuse antibacterial network, while releasing the internal stress of the stainless steel material and strengthening the material matrix.

[0062] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A high-antibacterial stainless steel, characterized in that, It comprises the following components in parts by weight: 18-20 parts chromium, 8-10 parts nickel, 0.05-0.15 parts carbon, 0.3-0.5 parts silicon, 1-1.8 parts manganese and 68-75 parts iron, and 0.1-0.5 parts antibacterial component; the antibacterial component includes silver acetylacetone.

2. The high antibacterial stainless steel according to claim 1, characterized in that: The antibacterial component also includes at least one of copper nitrate and zinc sulfate.

3. The high antibacterial stainless steel according to claim 2, characterized in that: The antibacterial component is a mixture of silver acetylacetone and copper nitrate.

4. The high antibacterial stainless steel according to claim 3, characterized in that: The mass ratio of silver acetylacetone to copper nitrate is 1:(1.8-2.2).

5. The method for preparing high antibacterial stainless steel according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Mix the formulated amounts of chromium, nickel, carbon, silicon, manganese and iron with the antibacterial components, add grinding aid and wetting agent, ball mill, and dry to obtain antibacterial alloy composite powder; S2. The antibacterial alloy composite powder is subjected to pressing, sintering, solution treatment and aging treatment in sequence to obtain the high antibacterial stainless steel.

6. The method for preparing high antibacterial stainless steel according to claim 5, characterized in that: In S1, the grinding aid is talc.

7. The method for preparing high antibacterial stainless steel according to claim 6, characterized in that, The sintering process in S2 includes a pre-decomposition stage: heating to 350-400℃ at a rate of 2-5℃ / min.

8. The method for preparing high antibacterial stainless steel according to claim 7, characterized in that, The sintering process in S2 also includes: First stage: Increase the temperature by 5-10℃ / min to 550-650℃; Second stage: Increase the temperature by 10-15℃ / min to 1150-1250℃.

9. The method for preparing high antibacterial stainless steel according to claim 5, characterized in that: The solution treatment temperature in S2 is 1050-1150℃, and the holding time is 60-90min.

10. The method for preparing high antibacterial stainless steel according to claim 5, characterized in that, The time-sensing processing in S2 includes: Phase 1: Incubate at 450-500℃ for 1-2 hours; Second stage: Keep warm at 500-550℃ for 1-2 hours.

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