Preparation method of high-strength wear-resistant antibacterial stainless steel

Abstract

The application relates to a preparation method of high-strength wear-resistant antibacterial stainless steel and belongs to the technical field of metal matrix composites, which comprises the following steps: preparing stainless steel powder with a particle size of 15-53 mu m, mixing the stainless steel powder with micron-grade SiC which has been subjected to surface modification treatment, wet-milling in a ball mill tank to obtain primary wet powder, and then drying to obtain completely dry primary powder; weighing equal mass of aluminum oxide monohydrate and aluminum hydroxide, mixing the two into an aqueous solution, then adding the primary powder, wet-milling in a ball mill tank to obtain secondary wet powder, and then drying to obtain completely dry secondary powder; roasting the secondary powder in a vacuum tube furnace to in-situ generate nano-aluminum oxide; and then pressure forming and vacuum sintering to obtain the target product. The micron-grade SiC particles and nano-grade Al2O3 particles are uniformly and dispersedly distributed in the stainless steel matrix, and the hardness and wear resistance of the antibacterial stainless steel are significantly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metal matrix composites, and relates to a preparation method of high-strength wear-resistant antibacterial stainless steel. BACKGROUND

[0002] Due to the influence of the epidemic in recent years, people's awareness of antibacterial has been greatly enhanced, and it is generally recognized that bacteria will adhere to many positions including hands, and the antibacterial requirements of public places including elevators, handrails, landscape sculptures and the like are also higher and higher, and the demand for antibacterial products has significantly increased, and the demand for antibacterial stainless steel has significantly increased. In public places, the application of antibacterial stainless steel is very extensive, such as elevator coverings and buttons, handrails, landscape sculptures, curtain walls and the like.

[0003] In the 1990s, a new type of ferritic antibacterial stainless steel was developed by Nisshin Steel, which has good processability and antibacterial property. Subsequently, Japan Kawasaki Steel Company expanded the variety of silver-containing stainless steel. Today, the antibacterial stainless steel produced in Japan has been applied in the fields of household appliances, kitchen utensils, cutters and the like.

[0004] Antibacterial stainless steel is mainly alloy type, and generally Cu, Ag and other alloy elements with bactericidal effect are added in the stainless steel. However, the mechanical property of ordinary antibacterial stainless steel is usually low, the strength is low and the wear resistance is poor, and it cannot be used in public places, especially in scenes requiring high wear resistance, so the application range is greatly limited. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a preparation method of high-strength wear-resistant antibacterial stainless steel to solve the problems of poor strength and wear resistance of the existing antibacterial stainless steel.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0007] A preparation method of high-strength wear-resistant antibacterial stainless steel, comprising the following steps:

[0008] 1. A preparation method of high-strength wear-resistant antibacterial stainless steel, comprising the following steps:

[0009] S1. Preparing stainless steel powder with a particle size of 15-53 microns, and performing surface modification treatment on micron-sized SiC to remove part of residual raw materials and a small amount of impurities inevitably introduced during the preparation of SiC powder, so as to prevent adverse effects on the material performance;

[0010] S2. Mixing the micron-sized SiC after surface modification treatment with the stainless steel powder, and performing wet grinding in a ball mill tank to obtain a first wet powder, and drying the first wet powder to obtain completely dry first powder;

[0011] S3 take equal mass of monohydrate aluminum oxide and aluminum hydroxide, and make it into an aqueous solution, then add the primary powder, wet mill in a planetary ball mill jar, get secondary wet powder, dry the secondary wet powder to get completely dry secondary powder, vacuum calcine the secondary powder, the calcination temperature is 500-800℃, in-situ generate nano-alumina, get the powder containing nano-alumina;

[0012] S4 pressure form the powder containing nano-alumina to get a green body;

[0013] S5 vacuum sinter the green body to get a high-strength wear-resistant antibacterial stainless steel product.

[0014] Optionally, in step S1, the preparation of the stainless steel powder comprises the following steps: prepare the alloy powder according to the following weight percentage: C 0.02-0.08%, Si 0.25-0.45%, Mn 1.5-2.5%, Cu 2-4.5%, Cr 18-20%, Ni 0.5-0.9%, Ag 0.02-0.08%, Sc 0.001-0.01%, and the balance is Fe, melt and spray the prepared alloy powder, and screen out the stainless steel powder with a particle size of 15-53μm; in step S4, the pressure of the pressure forming is >200Mpa, and the pressure holding time is 10-90S; in step S5, the sintering temperature is 780-1050℃, and the sintering time is 5-36h.

[0015] Optionally, in step S2, wet mill in a planetary ball mill jar, the ball-to-material ratio is 10:1-80:1, the ball milling speed is 50-400r / min, and the ball milling time is 0.2-10h.

[0016] Optionally, in step S3, wet mill in a planetary ball mill jar, the ball-to-material ratio is 10:1-50:1, the ball milling speed is 10-250r / min, and the ball milling time is 0.1-5h.

[0017] Optionally, in step S2, the wet milling medium is alcohol, and the wet milling aid is stearic acid.

[0018] Optionally, in step S1, the particle size of the SiC is 200-1500nm.

[0019] Optionally, in step S1, the surface modification treatment is pickling.

[0020] Optionally, in step S1, SiC with a particle size of 5μm is used for surface modification treatment.

[0021] Optionally, in step S3, the secondary powder is calcined in a vacuum tube furnace.

[0022] Optionally, in step S5, the green body is sintered in a vacuum tube furnace.

[0023] The present application has the following advantages:

[0024] (1) By in-situ endogenous nano-sized aluminum oxide particles, effectively avoid the quality difference, uneven distribution problem after sintering of traditional process using doped aluminum oxide nanoparticles, greatly improve the heat and mass transfer process in the sintering process.

[0025] (2) By the synergistic effect of micron-sized SiC particles and nano-sized Al2O3 particles, the hardness and wear resistance of the antibacterial stainless steel are significantly improved, the method is simple, efficient, and conducive to the scale preparation of high-quality antibacterial stainless steel products.

[0026] (3) The material prepared by the method of the present application has a higher cost than the traditional casting process, but the product hardness increases by 120%, the wear resistance increases by 3-5 times, and still shows good prospects for use.

[0027] Other advantages, objects and features of the present application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and attained by the embodiments particularly pointed out in the written description and claims hereof. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to make the objects, technical solutions and advantages of the present application clearer, the preferred detailed description of the present application will be combined with the drawings as follows, wherein:

[0029] Figure 1 Scanning electron microscope image of the high-strength wear-resistant antibacterial stainless steel of the present application. DETAILED DESCRIPTION

[0030] The embodiments of the present application will be described below by specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure of the present specification. The present application can also be implemented or applied by different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be noted that the drawings provided in the following examples only illustrate the basic concept of the present application in a schematic manner, and the following examples and features in the examples can be combined with each other without conflict.

[0031] Wherein, the drawings are only used for illustrative explanation, the representation is only a schematic diagram, not a physical diagram, and cannot be understood as a limitation of the present application; in order to better illustrate the embodiments of the present application, some components in the drawings are omitted, enlarged or reduced, and do not represent the actual size of the product; for those skilled in the art, it is understandable that some known structures and their descriptions in the drawings can be omitted.

[0032] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar components; in the description of the present application, it is understood that if the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "back", etc. are based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationships in the drawings are only used for exemplary illustration and cannot be understood as a limitation on the present application, for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0033] Please refer to Figure 1 A preparation method of high-strength wear-resistant antibacterial stainless steel, comprising the following steps:

[0034] (1) Preparation of alloy powder:

[0035] The alloy powder is prepared according to the following weight percentage: C 0.02-0.08%, Si 0.25-0.45%, Mn 1.5-2.5%, Cu 2-4.5%, Cr 18-20%, Ni 0.5-0.9%, Ag 0.02-0.08%, Sc 0.001-0.01%, and the balance is Fe;

[0036] The prepared alloy powder is melted and sprayed, and the antibacterial stainless steel powder with a particle size of 15-53 μm is screened out for standby;

[0037] (2) Enhancement body powder pretreatment: micron-sized SiC is subjected to surface modification treatment to remove part of the residual raw materials and a small amount of impurities inevitably introduced during the preparation of SiC powder, and to prevent adverse effects on the material performance;

[0038] (3) First ball milling and mixing: the micron-sized SiC powder after surface modification treatment obtained in step (2) is mixed with the stainless steel powder obtained in step (1), and is added into a planetary ball mill jar for wet milling;

[0039] (4) Drying powder: after step (3) is completed, the wet powder is taken out and separated, and is baked in an oven until completely dry to obtain completely dry primary powder;

[0040] (5) Second ball milling and mixing: equal mass of aluminum hydroxide monohydrate and aluminum hydroxide is weighed and prepared into an aqueous solution, and the primary powder obtained in step (4) is added and poured into a ball mill jar to start re-milling;

[0041] (6) Drying powder: after the milling is completed, the wet powder is taken out and separated, and is baked in an oven until completely dry to obtain completely dry secondary powder;

[0042] (7) In-situ generation of nano-alumina: the secondary powder obtained in step (6) is calcined in a vacuum tube furnace, the calcination temperature is 500-800 DEG C;

[0043] (8) Pressing blank: the powder obtained in step (7) is formed at a pressure of > 200 Mpa, the holding time is 10-90 S, to obtain a pressing blank;

[0044] (9) Sintering: the pressing blank is sintered by using a vacuum tube furnace, the sintering temperature is 780-1050 DEG C, the sintering time is 5-36 h, to obtain a high-strength wear-resistant antibacterial stainless steel product.

[0045] The application realizes the uniform dispersion of the micron-sized SiC particles and the nano-sized Al2O3 particles in the stainless steel matrix by combining the ball-milling assisted dispersion of the micron-sized ceramic particles with the in-situ production of the nano-sized alumina nano-particles; the hardness and the wear resistance of the antibacterial stainless steel are effectively improved through the synergistic reinforcement effect, so that the service life of the material is greatly prolonged.

[0046] Further, in step (2), the particle size of the SiC powder is 200-1500 nm, and the surface modification treatment is pickling.

[0047] Further, in step (3), the wet grinding medium is alcohol, and the ball milling aid is stearic acid; the ball-to-material ratio is 10:1-80:1, the ball milling speed is 50-400 r / min, and the ball milling time is 0.2-10 h.

[0048] Further, in step (5), the ball-to-material ratio is 10:1-50:1, the ball milling speed is 10-250 r / min, and the ball milling time is 0.1-5 h.

[0049] The application realizes excellent antibacterial performance by alloying copper (Cu) and silver (Ag) in terms of composition; the strength and the wear resistance of the product are significantly improved by realizing the uniform dispersion of the micron-sized SiC particles and the nano-sized Al2O3 particles in the stainless steel matrix in terms of structure, so that the inevitable dispersion difference problem in the mixed reinforcement of the micron-sized reinforcement and the nano-sized reinforcement is solved, wherein the micron-sized SiC mainly bears the friction load, and the nano-sized Al2O3 particles are used to disperse strengthen the matrix in the places where the micron-sized SiC particles are less distributed, so as to as far as possible improve the hardness and the wear resistance of the matrix and reduce the wear rate.

[0050] Example 1

[0051] A preparation method of a high-strength wear-resistant antibacterial stainless steel, comprising the following steps:

[0052] (1) Preparation of alloy powder

[0053] The alloy powder is prepared according to the following weight percentage: C 0.08%, Si 0.25%, Mn 2%, Cu 4.5%, Cr 18%, Ni 0.7%, Ag 0.04%, and the balance of Fe; the prepared alloy powder is smelted and sprayed, and the stainless steel powder with a particle size of 15 μm-53 μm is screened out for standby use (the same batch of stainless steel powder is used in Examples 1, 2 and Comparative Examples 1-4);

[0054] (2) Enhancement body powder pretreatment

[0055] The SiC powder with a particle size of 5 μm is selected and subjected to surface pickling;

[0056] (3) First-time ball milling of powder

[0057] The micron-sized SiC powder subjected to surface modification treatment obtained in step (2) is mixed with the stainless steel powder obtained in step (1), and the mixed powder is added into a planetary ball mill tank for wet milling; the wet milling medium is alcohol, and the ball milling aid is stearic acid; the ball-to-powder ratio is 20:1, the ball milling speed is 350 r / min, and the ball milling time is 5 h;

[0058] (4) Drying of powder

[0059] After the end of step (3), the wet powder is taken out and separated, and is baked in an oven until completely dried to obtain completely dried primary powder;

[0060] (5) Second-time ball milling of powder

[0061] The same mass of aluminum oxide monohydrate and aluminum hydroxide is weighed and prepared into an aqueous solution, the dry powder obtained in step (4) is added, and is poured into a ball mill tank to start the second-time ball milling; the ball-to-powder ratio is 20:1, the ball milling speed is 150 r / min, and the ball milling time is 2 h;

[0062] (6) Drying of powder

[0063] After the end of the ball milling, the wet powder is taken out and separated, and is baked in an oven until completely dried to obtain completely dried secondary powder;

[0064] (7) In-situ generation of nano-alumina

[0065] The secondary powder obtained in step (6) is subjected to calcination in a vacuum tube furnace, the calcination temperature is 800 °C, and the calcination time is 2 h;

[0066] (8) Pressing of green body

[0067] The powder obtained in step (7) is formed at a pressure of 400 MPa, and the pressure maintaining time is 20 s to obtain a pressed green body;

[0068] (9) Sintering and forming

[0069] The green compact is sintered in a vacuum tube furnace, the sintering temperature is 1050℃, and the sintering time is 8h.

[0070] The sintered sample is polished and polished to obtain the final product.

[0071] Example 2

[0072] A method for preparing a high-strength wear-resistant antibacterial stainless steel comprises the following steps:

[0073] (1) Reinforcement powder pretreatment

[0074] SiC powder with a particle size of 2μm is selected for surface pickling;

[0075] (2) First ball milling

[0076] The micron-sized SiC powder after surface modification treatment obtained in step (1) is mixed with stainless steel powder, and the mixed powder is added to a planetary ball mill tank for wet milling; the wet milling medium is alcohol, and the ball milling aid is stearic acid; the ball-to-material ratio is 30:1, the ball milling speed is 320r / min, and the ball milling time is 12h;

[0077] (3) Drying powder

[0078] After step (2) is completed, the wet powder is taken out and separated, and is baked in an oven until completely dry to obtain completely dry primary powder;

[0079] (4) Second ball milling

[0080] An equal mass of aluminum oxide monohydrate and aluminum hydroxide is weighed and prepared into an aqueous solution, the dry powder obtained in step (3) is added, and the ball mill tank is poured into the ball mill tank to start ball milling again; the ball-to-material ratio is 30:1, the ball milling speed is 180r / min, and the ball milling time is 4h;

[0081] (5) Drying powder

[0082] After ball milling is completed, the wet powder is taken out and separated, and is baked in an oven until completely dry to obtain completely dry secondary powder;

[0083] (6) In-situ generation of nano-alumina,

[0084] The secondary powder obtained in step (6) is calcined in a vacuum tube furnace, the calcination temperature is 800℃, and the calcination time is 2h;

[0085] (7) Pressing compact

[0086] The powder obtained in step (6) is formed at a pressure of 200Mpa, and the pressure holding time is 20S;

[0087] (8) Sintering

[0088] Sintering temperature: 980℃, sintering time: 8h;

[0089] The final product was obtained after polishing and polishing treatment of the sintered sample.

[0090] Comparative Example 1 (without adding micron-sized SiC and nano-sized Al2O3)

[0091] (1) Ball milling of mixed powder

[0092] A certain amount of stainless steel powder was weighed and ball milled by adding the powder into a planetary ball mill tank for wet milling; the wet milling medium was alcohol, and the ball milling aid was stearic acid; the ball-to-powder ratio was 20:1, the ball milling speed was 350 r / min, and the ball milling time was 5h;

[0093] (2) Drying of powder

[0094] After step (2) was completed, the wet powder was taken out and separated, and was baked in an oven until completely dry;

[0095] (3) Pressing of green body

[0096] The powder was formed at a pressure of 400Mpa, and the holding time was 20S;

[0097] (4) Sintering of formed body

[0098] Sintering was performed using a vacuum tube furnace, with a sintering temperature of 1050℃ and a sintering time of 8h;

[0099] The final product was obtained after polishing and polishing treatment of the sintered sample.

[0100] Comparative Example 2 (without adding micron-sized SiC)

[0101] (1) Ball milling of mixed powder

[0102] A certain amount of stainless steel powder was weighed, and an equal amount of aluminum monohydrate and aluminum hydroxide was weighed to form an aqueous solution, which was mixed and then poured into a ball mill tank for ball milling; the ball-to-powder ratio was 20:1, the ball milling speed was 150 r / min, and the ball milling time was 2h;

[0103] (2) Drying of powder

[0104] After ball milling was completed, the wet powder was taken out and separated, and was baked in an oven until completely dry;

[0105] (3) In-situ generation of nano-alumina

[0106] The powder obtained in step (2) was calcined in a vacuum tube furnace at a calcination temperature of 800℃ for 2h;

[0107] (4) Pressing of green body

[0108] The powder is formed at a pressure of 400 MPa, and the pressure maintaining time is 20 s.

[0109] (5) Sintering

[0110] The sintering is performed by using a vacuum tube furnace, the sintering temperature is 1050℃, and the sintering time is 8 h.

[0111] The final product is obtained after polishing and polishing treatment of the sintered sample.

[0112] Comparative Example 3 (without adding nano-Al2O3)

[0113] (1) Reinforcing powder pretreatment

[0114] First, the SiC powder with a particle size of 5 μm is selected for surface pickling;

[0115] (2) First ball milling of mixed powder

[0116] The micron-sized SiC powder after surface modification treatment obtained in step (1) is mixed with stainless steel powder, and the mixed powder is added to a planetary ball mill tank for wet milling; the wet milling medium is alcohol, and the ball milling aid is stearic acid; the ball-to-powder ratio is 20:1, the ball milling speed is 350 r / min, and the ball milling time is 5 h.

[0117] (3) Drying of powder

[0118] After step (2) is completed, the wet powder is taken out and separated, and is baked in an oven until completely dry.

[0119] (4) Pressing of green body

[0120] The powder is formed at a pressure of 400 MPa, and the pressure maintaining time is 20 s.

[0121] (5) Sintering

[0122] The sintering is performed by using a vacuum tube furnace, the sintering temperature is 1050℃, and the sintering time is 8 h.

[0123] The final product is obtained after polishing and polishing treatment of the sintered sample.

[0124] Comparative Example 4 (changing the way of adding nano-Al2O3)

[0125] (1) Reinforcing powder pretreatment

[0126] First, the SiC powder with a particle size of 5 μm is selected for surface pickling;

[0127] (2) First ball milling of mixed powder

[0128] ​​​​​​​​​​The micron-sized SiC powder after surface modification treatment obtained in step (1) is mixed with stainless steel powder, and the mixed powder is added into a planetary ball mill jar for wet milling; the wet milling medium is alcohol, and the ball milling aid is stearic acid; the ball-to-powder ratio is 20:1, the ball milling speed is 350 r / min, and the ball milling time is 5 h;

[0129] (3) Drying the powder

[0130] After step (2) is completed, the wet powder is taken out and separated, and is baked in an oven until completely dry;

[0131] (4) Second ball milling for mixing the powder

[0132] A certain amount of nano-sized alumina particles with a nominal particle size of 50 nm is weighed, the dry powder obtained in step (3) is added, and is poured into a ball mill jar to start the second ball milling; alcohol is added for wet milling, the ball-to-powder ratio is 20:1, the ball milling speed is 150 r / min, and the ball milling time is 2 h;

[0133] (4) Drying the powder

[0134] After the ball milling is completed, the wet powder is taken out and separated, and is baked in an oven until completely dry;

[0135] (5) Pressing the green body

[0136] The powder is formed at a pressure of 400 MPa, and the pressure maintaining time is 20 s;

[0137] (6) Sintering the formed body

[0138] The vacuum tube furnace is used for sintering, the sintering temperature is 1050 ℃, and the sintering time is 8 h;

[0139] After the sintered sample is treated by grinding and polishing, the final product is obtained.

[0140] Table 1 shown below shows the mechanical property table of the products obtained in the examples and the comparative examples, from which it can be seen that the strength and wear resistance of the product obtained by using the preparation method of the present application are obviously higher than those of the prior art.

[0141] Table 1 Mechanical property table

[0142]

[0143] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application but not to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the present technical solutions, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A method for preparing high-strength, wear-resistant, and antibacterial stainless steel, characterized in that: Includes the following steps: S1. Prepare stainless steel powder with a particle size of 15μm~53μm by surface modification of micron-sized SiC. The preparation of stainless steel powder includes the following steps: alloy powder is prepared according to the following weight percentages: C 0.02~0.08%, Si 0.25~0.45%, Mn 1.5~2.5%, Cu 2~4.5%, Cr 18~20%, Ni 0.5~0.9%, Ag 0.02~0.08%, Sc 0.001~0.01%, with the balance being Fe. The prepared alloy powder is then smelted, sprayed, and sieved to obtain stainless steel powder with a particle size of 15μm~53μm. S2 mixes surface-modified micron-sized SiC with stainless steel powder and wet-mills it in a ball mill jar to obtain primary wet powder. The primary wet powder is then dried to obtain completely dry primary powder. Among them, wet grinding is carried out in a planetary ball mill jar, with a ball-to-material ratio of 10:1 to 80:1, a ball mill speed of 50 to 400 r / min, and a ball milling time of 0.2 to 10 h; S3 Weigh equal masses of monohydrate alumina and aluminum hydroxide, prepare an aqueous solution, add the primary powder, and wet grind in a ball mill jar to obtain secondary wet powder. Dry the secondary wet powder to obtain completely dry secondary powder. Vacuum calcinate the secondary powder at a temperature of 500-800℃ to generate nano-alumina in situ, thus obtaining powder containing nano-alumina. S4 The powder containing nano-alumina is pressure-formed to obtain a pressed blank; wherein the pressure of pressure forming is >200Mpa and the holding time is 10-90S; S5 involves vacuum sintering the pressed blank; the sintering temperature is 780-1050℃, and the sintering time is 5-36h.

2. The method for preparing a high-strength, wear-resistant, and antibacterial stainless steel according to claim 1, characterized in that: In step S3, wet grinding is carried out in a planetary ball mill jar with a ball-to-material ratio of 10:1 to 50:1, a ball milling speed of 10 to 250 r / min, and a ball milling time of 0.1 to 5 h.

3. The method for preparing a high-strength, wear-resistant, and antibacterial stainless steel according to claim 1, characterized in that: In step S2, the wet grinding medium is alcohol, and the wet grinding aid is stearic acid.

4. The method for preparing a high-strength, wear-resistant, and antibacterial stainless steel according to claim 1, characterized in that: In step S1, the particle size of SiC is 200-1500 nm.

5. The method for preparing a high-strength, wear-resistant, and antibacterial stainless steel according to claim 1, characterized in that: In step S1, the surface modification treatment is pickling.

6. The method for preparing a high-strength, wear-resistant, and antibacterial stainless steel according to claim 1, characterized in that: In step S1, SiC with a particle size of 5 μm is selected for surface modification treatment.

7. The method for preparing a high-strength, wear-resistant, and antibacterial stainless steel according to claim 1, characterized in that: In step S3, the secondary powder is calcined in a vacuum tube furnace.

8. The method for preparing a high-strength, wear-resistant, and antibacterial stainless steel according to claim 1, characterized in that: In step S5, the pressed green body is sintered in a vacuum tube furnace.

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