Preparation method of a medical stainless steel narrow thin strip
Through vacuum smelting and multiple drawing combined with precision rolling, a narrow thin strip of medical stainless steel with excellent mechanical properties and plasticity was prepared, which solved the problems of difficult plastic deformation and poor forming quality of domestic products.
Patent Information
- Application Number
- CN202411238578.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-05
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2044-09-05
AI Technical Summary
Domestic micron-grade medical stainless steel narrow strips have problems such as difficulty in plastic deformation and poor forming quality, which cannot meet the strict performance needs of implant interventional medical devices.
The wires are prepared by vacuum smelting of medical stainless steel ingots, combined with forging, rolling and homogenizing heat treatment, and the wires are prepared by thick pulling, medium pulling, fine pulling and micro pulling, and finally the mechanical properties of the narrow strip are adjusted through precision rolling and vacuum continuous annealing.
It achieves the strong plasticity and mechanical properties of narrow strips of medical stainless steel. The product is straight and curled in a free state, with bright and flat surface, and the tensile strength is between 800 and 2700 MPa.
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Figure CN119281812B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of medical devices, and particularly relates to a preparation method of a narrow and thin medical stainless steel strip. Background Art
[0002] The narrow and thin medical stainless steel strip has excellent characteristics such as strength, dimensional accuracy, surface finish, and biocompatibility, and has a wide range of applications in high-end medical devices. It is mainly used as the matrix braiding material for three types of medical devices such as microcatheters, guide wires, and stents.
[0003] With the development of minimally invasive medical technology, the size of the narrow and thin medical stainless steel strip is getting smaller and smaller, and its application prospects are also getting broader and broader. In the implantable and interventional medical industry that requires light, thin, short, and small devices, in addition to carrying traditional structural applications, the narrow and thin medical stainless steel strip is currently also developing in the directions of functions and electricity.
[0004] Domestic micron-level narrow and thin medical stainless steel strips often have problems such as difficult plastic deformation and poor forming quality, and cannot meet the performance requirements for strictly required implantable and interventional medical devices.
[0005] Therefore, in view of the deficiencies of the prior art, a preparation method of a narrow and thin medical stainless steel strip is provided. Summary of the Invention
[0006] In order to overcome the deficiencies of the prior art, the present invention provides a preparation method of a narrow and thin medical stainless steel strip, aiming to solve the problems of difficult plastic deformation and poor forming quality.
[0007] To achieve the above object, the present invention adopts the following technical solutions:
[0008] A preparation method of a narrow and thin medical stainless steel strip includes the following steps:
[0009] S1: Prepare wire rods: Vacuum melt medical stainless steel, and process the medical stainless steel ingot into wire rods by combining forging and rolling with heat treatment, and perform annealing treatment on the wire rods.
[0010] S2: Prepare wire filaments: Draw the wire rods into thick filaments, perform vacuum continuous annealing treatment on the thick filaments, draw the thick filaments into thin filaments, draw the thin filaments into ultra-thin filaments, and draw the ultra-thin filaments into micro-filaments.
[0011] S3: Prepare narrow and thin strip materials: Finally, roll the ultra-thin filaments into narrow and thin strip materials.
[0012] S4: Adjust mechanical properties: Perform vacuum continuous annealing treatment on the narrow and thin strip materials.
[0013] As a further improvement of the technical solution of the present invention, in step S1, the diameter of the wire rods is 5-8 mm, the annealing temperature is 800-1200 °C, and the time is 20-60 min.
[0014] As a further improvement of the technical solution of the present invention, in step S2,
[0015] S2.1: Use a disk wire drawing machine and a tungsten carbide wire drawing die to draw the medical stainless steel wire into a thick wire with a diameter of 0.5 - 1 mm at a speed of 1 - 20 m / min;
[0016] S2.2: Use an intermediate wire drawing machine and a tungsten carbide wire drawing die to draw the thick wire after vacuum continuous annealing into a thin wire with a diameter of 0.1 mm at a speed of 100 - 500 m / min;
[0017] S2.3: Use a fine wire drawing machine and a natural diamond wire drawing die to draw the thin wire into an ultra - thin wire with a diameter of 0.05 mm at a speed of 100 - 900 m / min;
[0018] S2.4: Use a micro wire drawing machine and a natural diamond wire drawing die to draw the ultra - thin wire into a micro wire with a diameter less than 0.05 mm.
[0019] As a further improvement of the technical solution of the present invention, in step S2.1, use a vacuum continuous annealing furnace to anneal the thick wire. When annealing, an inert gas is filled into the continuous annealing furnace. The annealing temperature is 850 - 1100 °C, and the annealing speed is 2 - 20 m / min.
[0020] As a further improvement of the technical solution of the present invention, in step S2, before rolling the narrow thin strip, calculate the diameter of the stainless steel wire corresponding to the required narrow thin strip size according to the principle of constant volume.
[0021] As a further improvement of the technical solution of the present invention, in step S2.1, an oily lubricant is used during the thick wire drawing process;
[0022] In steps S2.2 - S2.4, a water - based lubricant is used during the wire drawing process;
[0023] The wire drawing machine includes a slip wire drawing machine and a non - slip wire drawing machine.
[0024] As a further improvement of the technical solution of the present invention, in step S3: Use a precision rolling mill to roll the ultra - thin wire into a narrow thin strip at a speed of 50 - 200 m / min.
[0025] As a further improvement of the technical solution of the present invention, in step S3, an on - line width measuring instrument is provided at the rear end of the rolling mill roll of the precision rolling mill. By adjusting the roll reduction amount, the real - time width change on the width sensor is obtained;
[0026] The width of the narrow thin strip is 0.038 - 0.304 mm, and the thickness is 0.012 - 0.076 mm.
[0027] As a further improvement of the technical solution of the present invention, in step S4, a vacuum continuous annealing furnace is used to anneal the narrow thin strip to adjust the mechanical properties of the narrow thin strip. When annealing, an inert gas is filled into the continuous annealing furnace, the annealing temperature is 850-1100°C, and the annealing speed is 2-20 m / min.
[0028] As a further improvement of the technical solution of the present invention, it further includes step S5: inspecting the narrow thin strip: inspecting the dimensional accuracy, surface quality, and mechanical property consistency of the narrow thin strip.
[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0030] In the preparation method of the medical stainless steel narrow thin strip of the present invention, a medical stainless steel ingot is purified by high-vacuum melting, and a medical stainless steel wire rod is prepared by combining forging, rolling, and homogenization heat treatment; then a medical stainless steel wire is prepared by rough drawing, medium drawing, fine drawing, and micro drawing; a medical stainless steel narrow thin strip with a width of 0.038 mm to 0.304 mm and a thickness of 0.012 mm to 0.076 mm is prepared by precision rolling, and finally the mechanical properties of the medical stainless steel narrow thin strip are adjusted by vacuum continuous annealing. The preparation method of this medical stainless steel narrow thin strip has the characteristics of strong plasticity and meeting the mechanical property requirements. Description of the Drawings
[0031] The following further details the technology of the present invention in conjunction with the drawings and specific embodiments:
[0032] Figure 1 It is a schematic diagram of the strain morphology of Example 1 in the medical stainless steel narrow thin strip of the present invention;
[0033] Figure 2 It is a metallographic diagram of Example 1 in the medical stainless steel narrow thin strip of the present invention;
[0034] Figure 3 It is a schematic diagram of the strain morphology of Example 2 in the medical stainless steel narrow thin strip of the present invention;
[0035] Figure 4 It is a metallographic diagram of Example 2 in the medical stainless steel narrow thin strip of the present invention. Specific Embodiments
[0036] The following will clearly and completely describe the concept, specific structure, and technical effects generated by the present invention in conjunction with the embodiments and the drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The same reference numerals used throughout the drawings indicate the same or similar parts.
[0037] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. In addition, the descriptions such as up, down, left, and right used in the present invention are only relative to the mutual positional relationship of the components of the present invention in the drawings.
[0038] Example 1
[0039] Referring to Figures 1 to 4 , a method for preparing a medical stainless steel narrow thin strip, comprising the following steps:
[0040] S1: Prepare wire rods: Vacuum melt medical stainless steel, and process the medical stainless steel ingot into wire rods by combining forging and rolling with heat treatment, and perform annealing treatment on the wire rods.
[0041] S2: Prepare wire filaments: Draw the wire rods into thick wires, perform vacuum continuous annealing treatment on the thick wires, draw the thick wires into thin wires, draw the thin wires into ultra-thin wires, and draw the ultra-thin wires into micro-wires.
[0042] S3: Prepare narrow thin strip materials: Finally, roll the ultra-thin wires into narrow thin strip materials.
[0043] S4: Adjust mechanical properties: Perform vacuum continuous annealing treatment on the narrow thin strip materials.
[0044] S5: Inspect the narrow thin strip: Inspect the dimensional accuracy, surface quality, and mechanical property consistency of the narrow thin strip.
[0045] Among them, the medical stainless steel ingot is purified and melted by high vacuum, and the medical stainless steel wire rods are prepared by combining forging, rolling, and homogenization heat treatment; then the medical stainless steel wire filaments are prepared by rough drawing, medium drawing, fine drawing, and micro drawing; the medical stainless steel narrow thin strip materials with a width of 0.038 mm to 0.304 mm and a thickness of 0.012 mm to 0.076 mm are prepared by precision rolling, and finally the mechanical properties of the medical stainless steel narrow thin strip materials are adjusted by vacuum continuous annealing. The method for preparing the medical stainless steel narrow thin strip has the characteristics of strong plasticity and meeting the mechanical property requirements. The prepared medical stainless steel narrow thin strip is straight and non-curled in the free state, with a bright and flat surface, no obvious oxidation, no pits, scratches, cracks and other defects, and the tensile strength is between 800 and 2700 MPa, meeting the mechanical property requirements.
[0046] In one embodiment, in step S1, a vacuum melting furnace is used to melt the medical stainless steel ingot, and the melting temperature, melting time, and melting times can be controlled to ensure the purity and cleanliness of the medical stainless steel ingot. The diameter of the wire rods is 5 to 8 mm, the annealing temperature is 800 to 1200 °C, and the time is 20 to 60 min.
[0047] In one embodiment, in step S2,
[0048] S2.1: Use a disk wire drawing machine and a tungsten carbide wire drawing die to draw a medical stainless steel wire rod to a thick wire with a diameter of 0.5 - 1 mm at a speed of 1 - 20 m / min;
[0049] S2.2: Use an intermediate wire drawing machine and a tungsten carbide wire drawing die to draw the thick wire after vacuum continuous annealing to a fine wire with a diameter of 0.1 mm at a speed of 100 - 500 m / min;
[0050] S2.3: Use a fine wire drawing machine and a natural diamond wire drawing die to draw the fine wire to an ultra - fine wire with a diameter of 0.05 mm at a speed of 100 - 900 m / min;
[0051] S2.4: Use a micro wire drawing machine and a natural diamond wire drawing die to draw the ultra - fine wire to a micro wire with a diameter less than 0.05 mm.
[0052] In step S2.1, use a vacuum continuous annealing furnace to anneal the thick wire. When annealing, fill the continuous annealing furnace with an inert gas. The annealing temperature is 850 - 1100 °C, and the annealing speed is 2 - 20 m / min. During the thick wire drawing process, use an oily lubricant.
[0053] In one embodiment, in step S2, before rolling the narrow thin strip, calculate the diameter of the stainless steel wire corresponding to the required narrow thin strip size according to the principle of constant volume. The length of the narrow thin strip remains unchanged before and after rolling. Therefore, it is only necessary that the cross - sectional area of the narrow thin strip is the same as that of the ultra - fine wire. Assume that the required width of the narrow thin strip is a and the thickness is b, then the diameter of the ultra - fine wire rod for rolling this narrow thin strip is .
[0054] In one embodiment, in step S2.1, use an oily lubricant during the thick wire drawing process; in steps S2.2 - S2.4, use an aqueous lubricant during the wire drawing process; the wire drawing machine includes a slip wire drawing machine and a non - slip wire drawing machine.
[0055] In one embodiment, in step S3: Using a precision rolling mill, the ultra-fine wire is rolled into a narrow and thin strip at a speed of 50 - 200 m / min. An on-line width measuring instrument is provided at the rear end of the rolling mill roller. By adjusting the roll gap, the real-time width change on the width sensor is obtained; the width of the narrow and thin strip is 0.038 - 0.304 mm, and the thickness is 0.012 - 0.076 mm. Preferably, the key to rolling the ultra-fine medical stainless steel wire into a narrow and thin medical stainless steel strip meeting the dimensional requirements lies in adjusting the rolling reduction. Preferably, an oily lubricant is used during the rolling of the narrow and thin medical stainless steel strip. The precision rolling speed of the narrow and thin medical stainless steel strip is between 40 - 60 m / min. If the speed is too slow, the production efficiency is low; if the speed is too fast, the wire will vibrate, affecting the rolling stability.
[0056] In one embodiment, in step S4, a vacuum continuous annealing furnace is used to anneal the narrow and thin strip to adjust its mechanical properties. When annealing, an inert gas is filled into the continuous annealing furnace. The annealing temperature is 850 - 1100 °C, and the annealing speed is 2 - 20 m / min.
[0057] In one embodiment, as shown in Figure 2 Prepare a narrow and thin medical stainless steel strip with a width of 0.100 mm and a thickness of 0.033 mm:
[0058] The medical stainless steel ingot is refined by a vacuum melting furnace, and the ingot is processed into medical stainless steel wire with a diameter of 5 mm through forging, rolling and heat treatment. The annealing temperature is 900 °C and the time is 30 min. Using a disk wire drawing machine and tungsten carbide wire drawing dies, the medical stainless steel wire is drawn to a thick wire with a diameter of 0.5 mm at a speed of 10 m / min, and the area reduction rate per pass is 10% - 15%. Under helium protection, the medical stainless steel thick wire is annealed by a vacuum continuous annealing furnace with a tube length of 2 meters. The annealing temperature is 1000 °C and the speed is 2 m / min. According to the principle of constant volume, the diameter of the medical stainless steel wire corresponding to the required size of the narrow and thin strip product is calculated to be 0.0648 mm. Using a non-slip medium wire drawing machine and tungsten carbide wire drawing dies, the thick wire with a diameter of 0.5 mm after continuous annealing treatment is drawn to a thin wire with a diameter of 0.1 mm at a speed of 500 m / min, and the area reduction rate per pass is 10% - 15%. Using a non-slip fine wire drawing machine and natural diamond wire drawing dies, the stainless steel wire with a diameter of 0.1 mm in the previous pass is drawn to an ultra-fine wire with a diameter of 0.0648 mm at a speed of 500 m / min, and the area reduction rate per pass is 10% - 15%. Using a precision rolling mill, by adjusting the distance between the two rolls and regulating the rolling reduction, the medical stainless steel ultra-fine wire is rolled into a medical stainless steel narrow and thin strip with a width and thickness of 0.100 mm and 0.033 mm at a rolling speed of 50 m / min. The medical stainless steel narrow and thin strip is straight and non-curled in the free state, with a bright and flat surface, no obvious oxidation, no pits, scratches and cracks and other defects, and the average tensile strength is 2622 MPa. The tensile curve and metallographic structure of the medical stainless steel narrow and thin strip product are as shown in the appendix Figure 1 shown, the horizontal axis is strain %, and the vertical axis is stress MPa.
[0059] Example 2
[0060] In one embodiment, referring to Figure 4 shown, a medical stainless steel narrow and thin strip with a width of 0.0635 mm and a thickness of 0.0127 mm is prepared:
[0061] The medical stainless steel ingot is refined by a vacuum melting furnace, and the ingot is processed into stainless steel wire with a diameter of 5 mm through forging, rolling and heat treatment. The annealing temperature is 900 °C and the time is 30 min. Using a disk wire drawing machine and tungsten carbide wire drawing dies, the medical stainless steel wire is drawn to a thick wire with a diameter of 0.5 mm at a speed of 10 m / min, and the area reduction per pass is 10% - 15%. Under helium protection, the medical stainless steel thick wire is annealed in a vacuum continuous annealing furnace with a tube length of 2 meters. The annealing temperature is 1000 °C and the speed is 2 m / min. According to the principle of constant volume, the diameter of the medical stainless steel wire corresponding to the size of the required narrow and thin strip product is calculated to be 0.0321 mm. Using a non-slip medium wire drawing machine and tungsten carbide wire drawing dies, the thick wire with a diameter of 0.5 mm after continuous annealing treatment is drawn to a thin wire with a diameter of 0.1 mm at a speed of 500 m / min, and the area reduction per pass is 10% - 15%. Using a non-slip fine wire drawing machine and natural diamond wire drawing dies, the stainless steel wire with a diameter of 0.1 mm in the previous pass is drawn to an ultra-fine wire with a diameter of 0.05 mm at a speed of 500 m / min, and the area reduction per pass is 10% - 15%. Using a slip micro wire drawing machine and natural diamond wire drawing dies, the ultra-fine wire with a diameter of 0.05 mm in the previous pass is drawn to a medical stainless steel micro wire with a diameter of 0.0321 mm at a speed of 100 m / min, and the area reduction per pass is 10% - 15%. Using a precision rolling mill, by adjusting the distance between the two rolls and regulating the rolling reduction, the medical stainless steel ultra-fine wire is rolled into a medical stainless steel narrow and thin strip with a width and thickness of 0.0635 mm and 0.0127 mm at a rolling speed of 50 m / min. The mechanical properties of the medical stainless steel narrow and thin strip are adjusted by vacuum continuous annealing. Under helium protection, the stainless steel thick wire is annealed in a vacuum continuous annealing furnace with a tube length of 2 meters. The annealing temperature is 900 °C and the speed is 20 m / min. The medical stainless steel narrow and thin strip is straight and non-curled in the free state, with a bright and flat surface, no obvious oxidation, no pits, scratches and cracks and other defects, and the average tensile strength is 840 MPa. The tensile property curve and metallographic structure of the medical stainless steel narrow and thin strip product are as shown in Figure 2 The horizontal axis is strain % and the vertical axis is stress MPa.
[0062] For other contents of the preparation method of the medical stainless steel narrow and thin strip described in the present invention, reference can be made to the prior art and will not be elaborated here.
[0063] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Therefore, any modifications, equivalent changes and decorations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.
[0064] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.
[0065] In the present invention, unless otherwise clearly defined and limited, terms such as "installed", "connected", "connected to", "fixed" and the like should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
Claims
1. A method for preparing a medical stainless steel narrow thin strip, characterized in that: The following steps are involved: S1: Preparation of wire: vacuum melting of medical stainless steel, forging and rolling combined with heat treatment to process the medical stainless steel ingot into wire with a diameter of 5-8 mm, and annealing the wire at a temperature of 800-1200°C for 20-60 min; S2: preparing wire: before rolling the narrow thin strip, the diameter of the stainless steel wire corresponding to the required narrow thin strip size is calculated according to the volume invariance principle, the wire is drawn into a thick wire, the thick wire is subjected to vacuum continuous annealing treatment, the thick wire is drawn into a thin wire, the thin wire is drawn into an ultra-fine wire, and the ultra-fine wire is drawn into a micro-wire; S2.1: Use a disc wire drawing machine and a tungsten carbide wire drawing die to draw the medical stainless steel wire into a thick wire with a diameter of 0.5~1mm at a speed of 1~20m / min, and use a vacuum continuous annealing furnace to anneal the thick wire. During the annealing, inert gas is filled into the continuous annealing furnace. The annealing temperature is 850~1100℃ and the annealing speed is 2~20m / min; S2.2: Use a medium drawing machine and a tungsten carbide drawing die to draw the thick wire after vacuum continuous annealing at a speed of 100-500 m / min to a thin wire with a diameter of 0.1 mm; S2.3: Use a fine drawing machine and a natural diamond drawing die to draw the filament at a speed of 100-900 m / min to an ultra-fine filament with a diameter of 0.05 mm; S2.4: Use a micro-drawing machine and a natural diamond drawing die to draw the ultra-fine wire into a micro-wire with a diameter less than 0.05 mm; S3: Preparation of narrow and thin strips: Use a precision calender to roll ultrafine wires or microwires into narrow and thin strips at a speed of 50-200 m / min. An online width measuring instrument is installed at the rear end of the roller of the precision calender. By adjusting the roller pressure, the real-time width change on the width sensor is obtained; S4: Adjusting mechanical properties: Vacuum continuous annealing is performed on the narrow and thin strip to adjust the mechanical properties of the narrow and thin strip. During annealing, an inert gas is filled into the continuous annealing furnace. The annealing temperature is 850~1100℃ and the annealing speed is 2~20m / min.
2. The method for preparing a medical stainless steel narrow thin strip according to claim 1, characterized in that: In step S2.1, an oil-based lubricant is used during the rough drawing process; In steps S2.2-S2.4, a water-based lubricant is used during the wire drawing process; Wire drawing machines include slip wire drawing machines and non-slip wire drawing machines.
3. The method for preparing a medical stainless steel narrow thin strip according to claim 1, characterized in that: In step S3, the narrow thin strip has a width of 0.038-0.304 mm and a thickness of 0.012-0.076 mm.
4. The method for preparing a medical stainless steel narrow thin strip according to claim 1, characterized in that: The method further comprises step S5: inspecting the narrow thin strip: inspecting the dimensional accuracy, surface quality and mechanical property consistency of the narrow thin strip.
Citation Information
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