Medical antibacterial cold-rolled sheet and method for producing the same

Abstract

The application discloses a production method of medical antibacterial cold-rolled sheet, which comprises the following steps: sequentially processing liquid iron through a liquid iron dephosphorization process, a TSR furnace full-liquid iron smelting, LF refining, continuous casting, heating furnace heating, hot rolling and coiling processes to obtain a steel coil; and sequentially performing cold rolling, annealing and pickling and on-line flattening on the steel coil to obtain the medical antibacterial cold-rolled sheet. The medical antibacterial cold-rolled sheet has good processing performance, the thickness of the steel can be reduced, and the comprehensive cost can be saved by more than 30%. The process can not be carried out through a bell-type annealing, and after the hot rolling, the high-temperature coiling and the slow cooling pit heat preservation can be directly utilized for the antibacterial heat treatment process of the high-temperature self-timing of the steel strip, so that the antibacterial heat treatment process after the hot-rolled product is taken off line is reduced, the production process is shortened, and the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cold-rolled sheet, in particular to a medical antibacterial cold-rolled sheet and a production method thereof. BACKGROUND

[0002] Medical office furniture is an object that medical staff often contact in work, viruses, bacteria and fungi remaining on these objects have the potential risk of spreading diseases. Researchers have detected a large number of residual viruses on the surface of objects used by patients, which shows that furniture carriers increase the risk of virus transmission in public space. When a certain type of infectious disease occurs, hospitals need to receive a large number of patients, and hospital medical staff also become one of the susceptible groups. The application of antibacterial materials on medical office furniture can reduce the risk of illness of medical workers.

[0003] China has a huge demand for medical furniture market, but domestic office furniture enterprises are still in the initial stage of entering the medical industry, and the development mode and product style are also borrowed from foreign brands and products, so innovative improvement is urgently needed. The activity space of doctors can be divided into public area, diagnosis and treatment area, medical technology area, and inpatient area. In these spaces, the following furniture is often contacted: multifunctional office table, office chair, shielding screen, rest chair, storage cabinet, diagnosis and treatment bed, file cabinet, etc. For the antibacterial agent applied to furniture materials, the following points need to be met: non-toxic or extremely low toxicity, long effective antibacterial period; certain heat resistance. Among the two types of inorganic antibacterial materials, photocatalytic antibacterial agents need to be irradiated by ultraviolet light to play a sterilization role, and oxygen or water must also be present, which is not suitable for hospital furniture. Compared with this, nano Cu ion, Ag ion, TiO2 and other metal ion type materials have the characteristics of light resistance, chemical stability, safety and non-toxicity, and long-lasting antibacterial properties.

[0004] Medical medicine cabinets have high requirements for the material quality of steel due to their special use. In addition to having good antibacterial properties, atmospheric corrosion resistance, and high strength and plasticity, the flatness of the steel strip after opening and flattening must be good. Especially for steel plates with high strength level and wide width, if the flatness is not good, it will seriously affect the production and manufacturing of medical medicine cabinets.

[0005] There are mainly two methods for preparing the current medical antibacterial steel plate: one is to spray an antibacterial layer on the surface of the steel material, but this antibacterial coating faces the risk of falling off; patent CN 113151748 A discloses an antibacterial ferrite stainless steel cold-rolled sheet antibacterial heat treatment process, which includes the following steps: cover type furnace antibacterial heat treatment, hot annealing and pickling, cold rolling, cold annealing and pickling, re-coiling treatment, antibacterial heat treatment, and shearing and packaging. However, the cold-rolled sheet prepared by this process has poor ductility and high brittleness, and the effect is not ideal in actual processing and use. SUMMARY

[0006] In view of the prior art, the present application aims to provide a medical antibacterial cold-rolled coil and a production method thereof.

[0007] To achieve the above object, the present application adopts the following technical solution:

[0008] The present application provides a production method of a medical antibacterial cold-rolled coil, comprising the following steps: sequentially performing cold rolling, annealing and pickling, and online skin passing on a steel coil to obtain a medical antibacterial cold-rolled coil.

[0009] The cold rolling process: the total deformation of the steel coil is 60%-85%, the rolling passes are 5-15, the single-pass deformation rate is 5%-25%, the deformation of the first and second passes is <22%, the deformation of the last pass is 10%-13%, the spraying amount of rolling oil is >7000 l / min, the roughness of the middle roller is 0.4-0.6 μm, the roughness of the finishing roller is 0.1-0.15 μm, the finishing roller is changed in the second-to-last pass, the maximum rolling speed is 450 m / min, and the finishing roller pass speed is less than 300 m / min.

[0010] The annealing and pickling process: the annealing temperature is 860-910 ℃, cooling is performed after annealing, and then pickling is performed, and electrolytic sodium sulfate + electrolytic nitric acid + a mixed acid of nitric acid and hydrofluoric acid is used for pickling.

[0011] The online skin passing: the steel material after annealing and pickling is subjected to online skin passing on a cold rolling and pickling line, the roughness of the skin passing roller in the online skin passing is 0.080-0.012 μm, the skin passing pressure is 150-900 t, the elongation is 0.2-2.0%, and the steel coil after skin passing is directly wound on line to obtain the medical antibacterial cold-rolled coil.

[0012] Preferably, in the annealing and pickling process, the concentration of sodium sulfate is 170-210 g / l, the electrolysis temperature of the sodium sulfate section is 70-75 ℃, the concentration of nitric acid is 130-160 g / l, the electrolysis temperature of the nitric acid section is 50-55 ℃, the concentration of the mixed solution of nitric acid and hydrofluoric acid is 30-60 g / l, the mass ratio of nitric acid to hydrofluoric acid is (10-11):(1-1.5), and the electrolysis temperature of the nitric acid and hydrofluoric acid section is 50-60 ℃.

[0013] Preferably, the steel coil is obtained by sequentially subjecting molten iron to a molten iron dephosphorization process, TSR furnace full-molten iron smelting, LF refining, continuous casting, heating furnace heating, hot rolling, and coiling processes.

[0014] Preferably, in the TSR furnace full-molten iron smelting, a bottom blowing gas is used, CO2 is used in the early and middle stages, and argon is used in the later stage; the bottom blowing CO2 time is 10-15 minutes, and the bottom blowing CO2 flow rate is 220-310 Nm 3 / h; the flow rate of the late argon blowing is 220 Nm 3 / h, and the time is 15 min. After the mass ratio of the composition of the molten steel reaches the predetermined requirement, i.e., P≤0.020%, S≤0.005%, C≤0.010%, Cr: 16%-18%, the molten steel is tapped into a ladle to obtain the reduced molten steel.

[0015] As preferred, the step of the LF refining is: fine-tuning the composition, making white slag, first determining oxygen in the LF furnace, the oxygen content is ≤10 ppm, the control of the alloy and the metal cold charge is ≤150 kg / furnace, the alloy is added in advance according to the composition of the previous sample, the soft blowing stage can be entered 10 min after the alloy is added, the calcium wire is fed 250 m 20 min before the steel is poured; the soft blowing argon time is 15-20 min, the composition of the molten steel meets the composition ratio requirement and the temperature reaches the predetermined requirement, i.e., P≤0.015%, S≤0.004%, O≤0.0010%, N≤0.0015%, the molten steel is tapped, and the tapping temperature is 1585-1560℃.

[0016] As preferred, the step of the continuous casting is: the molten steel is settled for 5-15 min, the argon protection is used for the whole process of the continuous casting, the immersion nozzle is used with an upward angle of 15°, the production is carried out at a constant speed of 1.0 m / min, the electromagnetic stirring is used, and the liquid level fluctuation of the crystallizer is <2 mm, and the casting blank is produced.

[0017] The heating furnace has an in-furnace temperature of not less than 550℃, a residence time of 190-240 min, and a furnace atmosphere of weak reducing atmosphere, and the heating temperature is 1190℃-1250℃.

[0018] As preferred, the step of the hot rolling rolling is: the slab is descaled in a slab descaling box, and the descaling is used in the 1st, 3rd and 5th passes of the rough rolling mill; the rough rolling is carried out in 7 passes, the first pass reduction is 15%-25%, and the rough rolling final rolling temperature is 1150℃-1180℃; the finishing rolling is carried out in a furnace and roll mill+3 mill continuous rolling mode, the finishing descaling box is not used, the coiling furnace temperature is 1150±20℃, the finishing rolling opening rolling temperature is ≥1030℃, the final rolling temperature is ≥850℃, and the laminar cooling is not used.

[0019] As preferred, the step of the coiling process is: the coiling temperature is 720℃-820℃, the steel coil is directly lifted to the slow cooling pit for slow cooling for 48 hours after three passes of the coiling and bundling, the steel strip residual heat is used for the antibacterial treatment, and the 30-200 nm grade antibacterial Cu phase is obtained.

[0020] The second aspect of the present application provides the medical antibacterial cold-rolled sheet produced by the production method of the medical antibacterial cold-rolled sheet, and the medical antibacterial cold-rolled sheet comprises the following components by weight: C≤0.020%, Si 0.35-0.45%, Mn 0.25-0.45%, P≤0.020%, S≤0.005%, Cr 16.00-18.00%, Cu 2.5-5.0%, Ni≤0.50%, N≤0.015%, and the rest is Fe and impurities.

[0021] The third aspect of the present application provides the application of the medical antibacterial cold-rolled sheet produced by the production method of the medical antibacterial cold-rolled sheet in the preparation of the medical medicine cabinet.

[0022] The difficulty in improving the performance of the medical antibacterial cold-rolled sheet lies in how to ensure good elongation and yield ratio while improving the antibacterial performance, and how to improve the oxidation resistance and corrosion resistance of the steel at low temperature for a long time. In order to ensure that the medical antibacterial cold-rolled sheet has high elongation and low temperature resistance and corrosion resistance, the chemical composition is adjusted and an appropriate amount of copper alloy is added, combined with high temperature coiling and slow cooling pit heat preservation process to realize the precipitation of fine dispersed ε-Cu copper-rich antibacterial phase in the steel strip, so that the product has excellent antibacterial ability, and a low-cost medical antibacterial cold-rolled sheet with good antibacterial performance is produced, which has low harmful element content and banded structure level, and has good corrosion resistance and forming performance.

[0023] The medical medicine cabinet cold-rolled sheet obtained by using the above chemical composition, rolling process and heat treatment process has uniform ferrite structure at room temperature, high toughness and plasticity, excellent antibacterial performance and forming performance, the tensile strength Rm is greater than or equal to 480 MPa, the yield strength is greater than or equal to 258 MPa, and the elongation is greater than or equal to 28%, and the hardness is less than or equal to 170 HV. Using the medical medicine cabinet cold-rolled sheet as raw material can effectively avoid the stamping or bending cracking phenomenon, and plays a positive role in ensuring the safety of medical medicine storage.

[0024] The beneficial effects of the present application are as follows:

[0025] The medical antibacterial cold-rolled sheet has good processing performance, the thickness of the steel can be thinned, and the comprehensive cost can be saved by more than 30%. After using the medical medicine cabinet cold-rolled sheet, the weight of the medical medicine cabinet can be reduced, the overall performance can be increased, and the cost can be reduced, which has significant economic and social benefits.

[0026] Traditionally produced medical antibacterial steel coils have high strength and hardness, but are also brittle, have poor formability, and poor corrosion resistance. This new process eliminates the need for annealing in a bell-type enclosure. After hot rolling, the steel strip can be directly subjected to high-temperature self-tempering via high-temperature coiling and slow cooling pit insulation to achieve the antibacterial heat treatment process. This reduces the antibacterial heat treatment process after the hot-rolled products come off the production line, ensuring that the products have excellent antibacterial properties while maintaining their corrosion resistance and toughness. It also shortens the production process and reduces production costs. Detailed Implementation

[0027] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0028] As described in the background section, the present invention provides a method for producing medical antibacterial cold-rolled coils, characterized by comprising the following steps:

[0029] (1) A hot metal dephosphorization process and TSR furnace full hot metal smelting are adopted. In the early stage (when the carbon content ω[C] in the molten pool is ≥1.2%) and the middle stage (0.6% ≤ ω[C] < 1.2%), CO2 is used for bottom blowing according to decarburization requirements. The weak oxidizing property of CO2 enhances molten pool decarburization, increases bottom blowing stirring capacity, and reduces chromium oxidation loss, achieving low-phosphorus, low-oxygen, decarburized chromium-preserving smelting in the TSR furnace, thus reducing production costs. The bottom blowing CO2 time is 10–15 minutes, and the bottom blowing CO2 flow rate is 220–310 Nm3 / h. In the later stage (when ω[C] ≤ 0.6%), argon is used for bottom blowing, with a bottom blowing argon flow rate of 220 Nm3 / h. 3 / h, time is 15min. After the mass ratio of the molten steel composition reaches the predetermined requirements, namely: P≤0.020%, S≤0.005%, C≤0.010%, Cr:16%~18%, the steel is tapped into the ladle to obtain reduced molten steel.

[0030] (2) LF Refining: Fine-tuning the composition and creating white slag. First, determine the oxygen content before LF refining; the oxygen content should be ≤10ppm. Control the addition of alloy and cold metal materials to ≤150kg / furnace. During the soft blowing stage, feed 250m of calcium wire 20 minutes before steelmaking. The soft blowing argon time must be 15-20 minutes. Soft blowing must not expose the molten steel; the standard for soft blowing is based on slag surface creep. After the molten steel composition meets the required proportions and the temperature reaches the predetermined requirements, tap the molten steel at a temperature of 1585-1560℃. The LF ladle refining process produces molten steel with low sulfur and phosphorus content (P ≤0.015%, S ≤0.004%), low oxygen and nitrogen content, and high purity (ΣO ≤0.0010%, N ≤0.0015%).

[0031] (3) Continuous casting process: The molten steel is poured from the exit to the start of the pouring, and the quenching time is 5-15 minutes. The whole process of continuous casting is protected by argon. The immersion nozzle is inclined by 15°. The production is carried out at a constant speed of 1.0 m / min. The electromagnetic stirring is used. The liquid level fluctuation of the crystallizer is less than 2 mm. The casting blank is produced.

[0032] (4) Heating furnace heating: The temperature of the furnace should not be lower than 550℃. The residence time is (190-240) minutes. The furnace atmosphere is weak reducing atmosphere. The heating temperature is 1190℃-1250℃.

[0033] (5) Hot rolling process: To reduce the temperature drop of the slab rolling line, the descaling passes need to be reduced and reasonably distributed, which can effectively remove the iron scale. A special descaling scheme is adopted: one pass of the slab descaling box, and the first, third and fifth passes of the rough rolling mill. The rough rolling is carried out in 7 passes. The first pass reduction rate is 15%-25%. The rough finishing temperature is 1150℃-1180℃. The production is organized according to the slow furnace discharge, fast rolling and high temperature rolling. The finishing rolling adopts the furnace and roll mill + 3 rack continuous rolling mode. The finishing descaling box is not used. The coiling furnace temperature is controlled at 1150±20℃. The finishing rolling opening temperature is ≥1030℃. The final rolling temperature is ≥850℃. The laminar cooling is not used.

[0034] (6) Coiling process: The coiling temperature is controlled in the range of 720℃-820℃. The steel coil is directly lifted to the slow cooling pit for slow cooling for 48 hours after three passes of bundling and packaging. The steel belt is treated for antibacterial treatment using the residual heat of the steel belt to obtain 30-200 nm antibacterial Cu phase. The steel coil is slowly cooled to prevent the hardness of the steel belt from being uneven.

[0035] (7) Cold rolling process: The total deformation of the 20-roll mill is controlled at 60%-85%. The rolling passes are 5-15 passes. The single pass deformation rate is 5%-25%. The first and second pass deformation is less than 22%. The last pass deformation is 10%-13%. The rolling oil spray amount is greater than 7000 l / min. The roughness of the middle roll is 0.4μm-0.6μm. The roughness of the finishing roll is 0.1μm-0.15μm. The finishing roll is changed in the second last pass. The rolling speed is controlled at a maximum speed of 450 m / min. The finishing roll pass speed is less than 300 m / min.

[0036] (8) Annealing pickling process: the annealing temperature is controlled at 860-910 ℃, after high-temperature holding is finished, air cooling + fog cooling is used for rapid cooling, and the steel strip is output from the annealing furnace after being cooled to below 80 ℃. After annealing, the steel coil is pickled, electrolytic sodium sulfate + electrolytic nitric acid + mixed acid of nitric acid and hydrofluoric acid are used for pickling, and the pickling process is as follows: sodium sulfate electrolysis (concentration 170-210 g / l, temperature 70-75 ℃)→nitric acid section (concentration 130-160 g / l, temperature 50-55 ℃)→nitric acid and hydrofluoric acid mixed acid section (concentration 30-60 g / l, temperature 50-60 ℃, wherein the mass ratio of nitric acid to hydrofluoric acid is (10-11):(1-1.5))→water cleaning.

[0037] (9) Online skin pass: the steel coil after annealing and pickling is subjected to large pressure online skin pass in a cold rolling and pickling line to improve the surface roughness and shape of the steel strip, a 2-roll skin pass mill is used for skin pass, the roughness of the skin pass roll is 0.080 μm-0.012 μm, the skin pass pressure is 150-900 t, the elongation is 0.2-2.0%, and the steel coil after skin pass is directly wound online and then taken offline.

[0038] The medical antibacterial cold-rolled sheet obtained by using the above production method comprises the following components by weight: C≤0.020%, Si 0.35-0.45%, Mn 0.25-0.45%, P≤0.020%, S≤0.005%, Cr 16.00-18.00%, Cu 2.5-5.0%, Ni≤0.50%, N≤0.015%, and the rest is Fe and impurities.

[0039] In order to enable those skilled in the art to more clearly understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below in combination with specific examples.

[0040] The test materials used in the embodiments of the present application are all conventional test materials in the art and can be purchased through commercial channels.

[0041] Example 1

[0042] The starting raw material used for smelting is molten iron, and the element ratio is: Si≤0.50%, P≤0.130, and temperature≥1250.

[0043] (1) The molten iron dephosphorization process and TSR furnace full molten iron smelting are used, the bottom blowing gas is blown in the early stage (when the carbon content ω[C]≥1.2%) and the middle stage (0.6%≤ω[C]<1.2%) according to the decarburization requirement, CO2 is used for blowing, the molten pool stirring performance is improved, and the decarburization reaction is strengthened, the bottom blowing CO2 time is 12 min, the bottom blowing CO2 flow rate is 280 Nm 3 / h; argon is used in the later stage (ω[C]≤0.6%), the bottom blowing argon flow rate is 220 Nm 3 / h, time is 15 min. When the composition of molten steel mass ratio reaches the predetermined requirements P≤0.020%, S≤0.005%, C≤0.010%, Cr: 16%~18%, tapping to ladle, get the reduced molten steel.

[0044] (2) LF refining: fine-tune the composition, white slag, into the LF furnace first oxygen, oxygen content 9 ppm, alloy and metal cold charge 142 kg / furnace. Soft blowing stage, 20 min before tapping, feeding calcium line 250 m. Soft blowing argon time 19 minutes, soft blowing can not be naked molten steel, soft blowing standard with the slag surface peristalsis. Molten steel composition meets the composition ratio requirements and temperature reaches the predetermined requirements, tapping, temperature is 1585℃. LF ladle refining process, the molten steel prepared, low sulfur and phosphorus content, [P]≤0.015%, [S]≤0.004%, low oxygen and nitrogen content, high purity of molten steel, Σ[O]≤0.0010%, [N]≤0.0015%.

[0045] (3) Continuous casting process: from the exit to the start of casting, the quieting 10 min, the whole process of continuous casting using argon protection pouring, the submerged entry nozzle using the angle of 15° upward, using 1.0 m / min constant speed production, using electromagnetic stirring, crystallizer liquid level fluctuation <2 mm, production of billet.

[0046] (4) heating furnace heating: into the furnace temperature 695℃, residence time 196 min, furnace atmosphere is weak reducing atmosphere, heating temperature 1197℃.

[0047] (5) hot rolling rolling process: slab descaling: slab descaling box is removed in one pass, rough rolling mill descaling is used in 1, 3, 5 passes. Rough rolling 7 passes, the first pass reduction rate 15%~25%, rough rolling final rolling temperature 1176℃, according to the slow furnace fast rolling, high temperature rolling organization production. The precision rolling adopts furnace rolling mill + 3 rack continuous rolling mode, the precision descaling box is not used, the coiling furnace temperature is controlled at 1158℃, the precision rolling opening temperature is 1037℃, the final rolling temperature is 898℃, the laminar cooling is not used.

[0048] (6) coiling process: coiling temperature 793℃, after three times of steel coil offline bundling, directly hoisted to the slow cooling pit for slow cooling for 48 hours, using the residual heat of steel strip to carry out antibacterial treatment, obtaining 30~200 nm level of antibacterial ε-Cu phase; ensure the slow cooling of steel coil to prevent the uneven hardness of steel strip.

[0049] (7) Cold rolling process: total deformation of 20-roller mill is controlled at 84.0%, the rolling passes are 5-15, the deformation of the first and second passes is ≤22%, the deformation of the last pass is 10%-13%, the spraying amount of rolling oil is >7000 l / min, the roughness of the middle roller is 0.4-0.6 μm, the roughness of the finishing roller is 0.1-0.15 μm, the finishing roller is changed in the second last pass, the rolling speed is controlled at a maximum speed of 450 m / min, and the finishing roller pass speed is less than 300 m / min.

[0050] (8) Annealing and pickling process: the annealing temperature is controlled at 860°C, after high-temperature holding, air cooling + mist cooling is used for rapid cooling, and the steel strip is output from the annealing furnace after cooling to 80°C. The steel coil after annealing is pickled, first electrolysis of sodium sulfate is performed, the concentration of sodium sulfate solution is 172 g / l, and the temperature is 71°C, then electrolysis of nitric acid is performed, the concentration of nitric acid solution is 152 g / l, and the temperature is 53°C, finally mixed acid electrolysis of nitric acid and hydrofluoric acid is performed, the concentration of mixed acid solution is 55 g / l, the mass ratio of nitric acid to hydrofluoric acid is 10:1-11:1, and the temperature is 55°C, and finally water cleaning is performed;

[0051] (9) On-line skin pass: the steel coil after annealing and pickling is subjected to on-line skin pass with large pressure in the cold rolling and pickling line to improve the surface roughness and shape of the steel strip, 2-roller skin pass mill is used for skin pass, the roughness of the skin pass roller is 0.085 μm, the skin pass pressure is 800 t, and the elongation is 0.3%, and the steel coil after skin pass is directly wound on-line and then taken offline.

[0052] The production parameters of Examples 2-6 are shown in Table 1, and the rest are the same as those of Example 1. The chemical compositions of the coils obtained in Examples 1-6 are shown in Table 2.

[0053] Comparative Example

[0054] In the present comparative example, cover furnace antibacterial heat treatment is performed in step (6), and the rest of the steps and parameters are the same as those of Example 4. The specific steps of antibacterial heat treatment are as follows: the temperature of the cover annealing furnace is 850°C, and the holding time is 6 hours.

[0055] Experimental Example

[0056] The obtained coiled sheets of Examples 1-6 and the comparative example were subjected to mechanical property testing, and the results are shown in Table 3. The yield strength, tensile strength, and elongation were tested according to the steps in GB / T 228.1-2021 “Metallic Materials-Tensile Testing-Part 1: Method of Test at Room Temperature”. The hardness was tested according to the steps in GB / T 4340.1-2009 “Metallic Materials-Vickers Hardness Test-Part 1: Test Method”. The cold bending test was tested according to the steps in GB / T 232-2010 “Metallic Materials-Bending Test Method”. The antibacterial rate was tested according to the steps in YBT 4171-2020 “Copper-Containing Antibacterial Stainless Steel”. The salt spray test was tested according to the steps in GB / T 10125-2021 “Artificial Atmosphere Corrosion Test-Salt Spray Test”.

[0057] Table 1: Process parameters of each example

[0058]

[0059]

[0060]

[0061] Table 2: Chemical composition content (wt%) of the coiled sheets obtained in each example

[0062] Example 1 2 3 4 5 6 Standard C 0.008 0.009 0.008 0.006 0.007 0.009 ≤0.020 Si 0.38 0.41 0.36 0.38 0.36 0.4 0.35-0.45 Mn 0.3 0.38 0.4 0.45 0.28 0.3 0.25-0.45 P 0.02 0.016 0.017 0.018 0.012 0.015 ≤0.020 S 0.003 0.002 0.003 0.004 0.003 0.002 ≤0.005 Cr 17.05 16.89 17.25 17.8 16.25 17.21 16.00-18.00 Cu 3 2.8 3.5 4.2 4.6 3.7 2.5-5.0 Ni 0.32 0.28 0.22 0.44 0.35 0.34 ≤0.50 N 0.009 0.008 0.01 0.009 0.011 0.015 ≤0.015

[0063] Table 3: Properties of the coiled sheets obtained in each example

[0064] Example 1 2 3 4 5 6 Comparative Example Standard Thickness 0.4 0.5 0.65 1.0 1.5 2.0 1.0 Yield Strength / MPa 334 393 320 354 332 347 328 ≥205 Tensile Strength / MPa 489 503 492 527 486 489 480 ≥420 Elongation / % 32 28 33 32 31 28 24 ≥22 Hardness / HV 144.8 143 150 141.36 142.25 145.55 154.86 ≤200 Cold Bending 2a Pass Pass Pass Pass Pass Pass Pass Antibacterial Rate / % ＞99 ＞99 ＞99 ＞99 ＞99 ＞99 ＞99 ＞99 Salt Spray Test Rating / Grade 10 10 10 10 10 10 10 ≥9

[0065] The antibacterial rate of the antibacterial cold-rolled sheet prepared by the present application is all above 99%, the elongation is large, the strength is high, the low-temperature resistance and corrosion resistance are excellent, the low-temperature impact toughness is strong, the antibacterial performance is improved while the good elongation and strength are ensured, and the oxidation resistance and corrosion resistance of the steel material at low temperature for a long time are improved. The technical effect of Example 4 in each example of the present application is the best. The comparative example and Example 4 use a traditional bell-type furnace antibacterial heat treatment, and the indicators are all lower than those of Example 4, the elongation is poor, the brittleness is poor, and the strength is low.

[0066] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for producing a medical antibacterial cold-rolled sheet, characterized by, The method comprises the following steps: The steel coil is sequentially subjected to cold rolling, annealing and pickling, and online leveling to obtain the medical antibacterial cold-rolled coil; The steel coil is prepared by the following steps: the molten iron is sequentially subjected to molten iron dephosphorization, TSR furnace full molten iron smelting, LF refining, continuous casting, heating furnace heating, hot rolling and coiling processes to obtain the steel coil; wherein the coiling temperature is 720-820℃, the steel coil is directly lifted to the slow cooling pit after three processes of coiling, packing and unloading, and is slowly cooled for 48 hours, the antibacterial treatment is performed by using the residual heat of the steel strip, and the 30-200nm antibacterial Cu phase is obtained; The cold rolling process: the total deformation of the steel coil is 60-85%, the rolling pass is 5-15, the single pass deformation rate is 5-25%, the first and second pass deformation is less than 22%, the last pass deformation is 10-13%, the rolling oil spraying amount is greater than 7000l / min, the roughness of the middle roller is 0.4-0.6μm, the roughness of the finishing roller is 0.1-0.15μm, the finishing roller is changed in the second last pass, the maximum rolling speed is 450m / min, and the finishing roller pass speed is less than 300m / min; The annealing and pickling process: the annealing temperature is 860-910℃, the steel is cooled after annealing, and then pickled, and the pickling is performed by using electrolytic sodium sulfate+electrolytic nitric acid+mixed acid of nitric acid and hydrofluoric acid; The online leveling: the annealed and pickled steel is subjected to online leveling in the cold rolling and pickling line, the roughness of the leveling roller is 0.080-0.012μm, the leveling pressure is 150-900t, the elongation is 0.2-2.0%, and the leveled steel coil is directly coiled after online leveling and then uncoiled to obtain the medical antibacterial cold-rolled coil; The medical antibacterial cold-rolled coil prepared by the production method comprises the following components by weight: C≤0.020%, Si 0.35-0.45%, Mn 0.25-0.45%, P≤0.020%, S≤0.005%, Cr 16.00-18.00%, Cu 2.5-5.0%, Ni≤0.50%, N≤0.015%, and the rest is Fe and impurities.

2. The method of producing a medical antibacterial cold-rolled sheet according to claim 1, characterized by, In the annealing and pickling process, the concentration of sodium sulfate is 170-210g / l, the electrolysis temperature of the sodium sulfate section is 70-75℃, the concentration of nitric acid is 130-160g / l, the electrolysis temperature of the nitric acid section is 50-55℃, the concentration of the mixed solution of nitric acid and hydrofluoric acid is 30-60g / l, the mass ratio of nitric acid to hydrofluoric acid is 10-11:1-1.5, and the electrolysis temperature of the nitric acid and hydrofluoric acid section is 50-60℃.

3. The method of producing a medical antibacterial cold-rolled sheet according to claim 1, characterized by, The TSR furnace smelts with bottom gas blowing, CO2 is used in the early and middle stages, and argon is used in the later stage; the bottom CO2 blowing time is 10-15 minutes, the bottom CO2 blowing flow is 220-310 Nm 3 / h; the flow of the later argon blowing is 220 Nm 3 / h, the time is 15 min, after the mass ratio of the steel water composition reaches the predetermined requirement, i.e. P≤0.020%, S≤0.005%, C≤0.010%, Cr 16%-18%, the steel is tapped to the ladle, and the reduced steel water is obtained.

4. The method of producing a medical antibacterial cold-rolled sheet according to claim 1, characterized by, The LF refining step is: fine-tuning the composition, white slag making, oxygen is first determined in the LF furnace, oxygen content is less than or equal to 10 ppm, the amount of alloy and metal cold charge is controlled to be less than or equal to 150 kg per furnace, alloy is added in advance according to the composition of the previous sample, 10 minutes after the alloy is added, the soft blowing stage can be entered, 20 minutes before the steel is poured, the calcium wire is fed at a speed of 250 m; the soft blowing argon time is 15-20 minutes, after the composition of the molten steel meets the composition ratio requirements and the temperature reaches the predetermined requirements, the molten steel is poured, the out-of-steel temperature is 1585-1560℃.

5. The method of producing a medical antibacterial cold-rolled sheet according to claim 1, characterized by, The continuous casting step is: the molten steel is settled for 5-15 minutes, argon protection is used for the whole continuous casting process, the immersion nozzle is inclined at an angle of 15°, a constant speed of 1.0 m / min is used for production, electromagnetic stirring is used, the liquid level fluctuation of the crystallizer is less than 2 mm, and the casting blank is produced; the heating furnace has an in-furnace temperature of not less than 550℃, a residence time of 190-240 minutes, and a furnace atmosphere of weak reducing atmosphere, and the heating temperature is 1190℃-1250℃.

6. The method of producing a medical antibacterial cold-rolled sheet according to claim 1, characterized by, The hot rolling step is: slab descaling: one pass of the slab descaling box, and the first, third and fifth passes of the rough rolling mill are used for descaling; rough rolling is performed for 7 passes, the first pass reduction rate is 15%-25%, and the rough rolling final rolling temperature is 1150℃-1180℃; the furnace and roll rolling mill and 3-mill continuous rolling mode are used for finish rolling, the finish descaling box is not used, the coiling furnace temperature is 1150±20℃, the finish rolling opening rolling temperature is greater than or equal to 1030℃, the final rolling temperature is greater than or equal to 850℃, and the laminar cooling is not used.

7. The use of the medical antibacterial cold-rolled sheet produced by the production method of the medical antibacterial cold-rolled sheet according to any one of claims 1-6 in the preparation of a medical medicine cabinet.

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