A method for preparing wire-cut molybdenum wire by high-speed cold drawing

Abstract

The present invention relates to the field of metal processing technology, and in particular to a method for preparing wire-cut molybdenum wire by high-speed cold drawing, comprising the following steps: S1, subjecting a molybdenum alloy wire rod to coarse hot drawing and hot drawing multi-mode string drawing to obtain a drawn wire; S2, coating the surface of the drawn wire with a graphite emulsion solution, and then drying the drawn wire to obtain a drawn wire with a dried graphite emulsion coating attached to the surface; S3, passing the drawn wire with the dried graphite emulsion coating through a vegetable oil circulation tank to be oiled and then entering a cold drawing die for high-speed cold drawing, thereby obtaining the wire-cut molybdenum wire. The wire-cut molybdenum wire produced by the method for preparing wire-cut molybdenum wire by high-speed cold drawing of the present invention has quality advantages such as uniform diameter, dense structure, and high surface hardness. The production speed can be increased to 260m / min to 400m / min, achieving the goals of high efficiency and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of metal processing, in particular to a method for preparing a wire-cut molybdenum wire by high-speed cold drawing. Background Art

[0002] Molybdenum wire is the primary electrode wire used in wire EDM. It is ideal for wire EDM machines, capable of cutting a wide range of steels and carbides, and processing extremely complex parts. Its stable discharge machining process effectively improves mold precision. Its low price, excellent toughness, high strength, good conductivity, and low elongation make it an ideal electrode tool for high-speed wire EDM.

[0003] The cold drawing technology currently used in the industry to produce finished wire-cut molybdenum wire has a drawing speed of no more than 150m / min, resulting in low production efficiency. The finished products also suffer from poor diameter uniformity and insufficient microstructure. Furthermore, since molybdenum is a difficult-to-machine metal, applying conventional high-speed cold drawing technology, already used for processing plastic metals like copper and steel, to high-speed cold drawing of molybdenum wire can lead to significant die wear due to lubrication issues, preventing mass production, and causing deep grooves on the molybdenum wire surface that can then develop into cracks, among other quality issues.

[0004] The conventional high-speed cold drawing preparation technology using plastic metal wires such as copper and steel uses full immersion liquid lubrication, that is, the wire is immersed in the lubricating liquid as a whole, and the drawing process is carried out in the liquid. The lubricating liquid has the dual functions of lubrication and cooling, which meets the lubrication and cooling needs required for high-speed cold drawing of plastic materials.

[0005] However, the above-mentioned liquid lubrication method cannot be directly transplanted to the high-speed cold drawing processing of difficult-to-deform metals such as molybdenum wire, because the drawing tower pulley is completely immersed in lubricating oil, and the wire needs to be wrapped around the tower pulley during the drawing process. Under the action of lubricating oil, the graphite emulsion coating on the surface of the wire is easily damaged. Since molybdenum wire is a difficult-to-deform metal, the lubricating liquid cannot smoothly enter the compression zone and sizing zone of the die hole during its cold drawing process. Therefore, it needs to rely on the graphite emulsion coating on its surface with a certain film-forming strength for lubrication. Once the graphite emulsion coating is damaged, the liquid lubricating oil cannot play a lubricating role, so dry friction is formed between the molybdenum wire and the die. In this way, the die is easily damaged and the purpose of mass production cannot be achieved. Moreover, due to the lack of lubrication, deep grooves will be formed on the surface of the molybdenum wire, which further causes cracks in the molybdenum wire. Summary of the Invention

[0006] In order to solve the shortcomings of the above-mentioned existing drawing technology, such as insufficient technical efficiency, large mold loss due to lubrication problems, inability to mass produce, and quality problems such as deep grooves on the molybdenum wire surface that then expand into cracks, the present invention provides a high-speed cold drawing preparation method for wire-cut molybdenum wire, which comprises the following steps:

[0007] S1. Processing the molybdenum alloy wire rod by coarse hot drawing and hot drawing multi-mode serial drawing to obtain drawn wire;

[0008] S2, coating the graphite emulsion solution on the surface of the drawn wire, and then drying the drawn wire to obtain a dried graphite emulsion coating;

[0009] S3, passing the drawn wire with the dried graphite emulsion coating through a vegetable oil circulation tank to be oiled and then entering a cold drawing die for high-speed cold drawing to obtain a wire-cut molybdenum wire.

[0010] In one embodiment, the drying process is to coat the drawn wire with graphite emulsion solution and then dry it in a heating zone with a temperature of 600-800° C. and a length of 400-900 mm at a speed of 30-50 m / min.

[0011] In one embodiment, the drying process is integrated with the hot-drawing multi-mode string drawing. Specifically, the heating zone of the drying process is the same as that of the hot-drawing multi-mode string drawing, that is, after the graphite emulsion solution is coated in the drying process, it is dried in the heating zone of the hot-drawing multi-mode string drawing. After drying, it does not pass through the hot-drawing multi-mode string drawing die, but directly enters the subsequent oil-dip cold drawing process, specifically as follows Figure 1 shown.

[0012] In one embodiment, the thickness of the dried graphite emulsion coating is 2-5 μm and the carbon content is 1200-3000 ppm.

[0013] In one embodiment, the graphite emulsion solution includes graphite emulsion and water; the weight ratio of the graphite emulsion to water is 1:4. Specifically, the graphite emulsion is an original graphite emulsion produced by a conventional manufacturer on the market.

[0014] In one embodiment, the specific gravity of the graphite emulsion solution is 1.0-1.06 g / cm 3 .

[0015] In one embodiment, the oil temperature in the vegetable oil circulation tank is 25-40°C.

[0016] In one embodiment, the vegetable oil circulation tank is provided with a temperature control device. Specifically, the temperature control device comprises a combination of an oil outlet pipe, a radiator, and an oil inlet pipe, with the radiator being disposed on the oil outlet pipe. The vegetable oil in the vegetable oil circulation tank flows along the oil outlet pipe, passes through the radiator for heat dissipation, and then re-enters the vegetable oil circulation tank through the oil inlet pipe. Preferably, multiple sets of oil outlet pipes and radiators can be provided to increase heat dissipation efficiency.

[0017] In one embodiment, the high-speed cold drawing process has a drawing speed of 260-400 m / min.

[0018] In one embodiment, the high-speed cold drawing process includes at least three cold drawing passes.

[0019] In one embodiment, the deformation amount of each cold drawing pass is 10-25%.

[0020] Based on the above, compared with the prior art, the method for preparing molybdenum wire by high-speed cold drawing provided by the present invention has the following beneficial effects:

[0021] 1. The present invention increases the speed of cold-drawn molybdenum wire from the industry average of 130m / min to 260m / min to 400m / min, achieving the goals of high efficiency and low cost.

[0022] 2. The present invention is a special high-speed cold drawing technology for difficult-to-deform metals. Unlike the full immersion method used in conventional high-speed cold drawing technologies for plastic materials such as copper and steel in other industries, the present invention utilizes the excellent lubrication properties of a special dried graphite emulsion coating to effectively solve the problems of rapid mold loss and difficulty in mass production caused by high-speed cold drawing of difficult-to-deform metals such as molybdenum.

[0023] 3. The present invention uses vegetable oil to control the temperature and cool the mold temperature by dipping the mold in vegetable oil, thereby reducing the service temperature of the mold and effectively improving the durability of the mold, that is, effectively reducing the rapid loss of the mold. The solution to the problem of rapid loss of the mold can achieve a good wire surface and avoid the deep grooves of the wire caused by mold loss and the cracks caused by the expansion of the deep grooves caused by continued cold drawing.

[0024] 4. The wire-cut molybdenum wire prepared by the present invention has quality advantages such as uniform diameter, dense structure, and high surface hardness. These quality advantages are key quality characteristics that enable the wire-cut molybdenum wire to achieve good use effects at the customer terminal. It has superior quality, high customer satisfaction, and high adhesion.

[0025] Other features and beneficial effects of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The objectives and other beneficial effects of the present invention can be achieved and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work. The positional relationships described in the drawings in the following description are based on the directions of the components drawn in the diagrams, unless otherwise specified.

[0027] Figure 1 This is a process diagram of a drying process in one embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the surface state of the finished molybdenum wire of Example 1;

[0029] Figure 3 This is a schematic diagram of the thickness of the dried graphite emulsion coating in Example 1;

[0030] Figure 4 This is a microscopic diagram of the metallographic structure of Example 1;

[0031] Figure 5 This is a microscopic diagram of the metallographic structure of Example 2;

[0032] Figure 6 This is a microscopic diagram of the metallographic structure of Example 3;

[0033] Figure 7 This is a microscopic diagram of the metallographic structure of Example 4;

[0034] Figure 8 This is a microscopic diagram of the metallographic structure of Comparative Example 1;

[0035] Figure 9 This is a microscopic diagram of the surface of the finished product of Comparative Example 1;

[0036] Figure 10 This is a microscopic diagram of the graphite emulsion coating after being damaged by the drawing tower wheel in Comparative Example 1;

[0037] Figure 11 for Figure 10 Enlarged image;

[0038] Figure 12 This is a microscopic diagram of the metallographic structure of Comparative Example 2;

[0039] Figure 13 This is a microscopic diagram of the surface of the finished product of Comparative Example 2;

[0040] Figure 14 Schematic diagram of the hot-drawing multi-mode string drawing process;

[0041] Figure 15 This is a schematic diagram of the surface state of the finished molybdenum wire of Comparative Example 2;

[0042] Figure 16 Schematic diagram of the thickness of the graphite emulsion coating compacted on the surface of the drawn wire in Comparative Example 2;

[0043] Figure 17 This is the actual crack detection diagram of comparative example 2;

[0044] Figure 18 This is the actual measurement style diagram of crack detection;

[0045] Figure 19 This is a schematic diagram of the process flow of the vegetable oil circulation tank in one embodiment of the present invention;

[0046] Figure 20 Schematic diagram of the molybdenum wire prepared in Example 1;

[0047] Figure 21 Microscopic diagram of molybdenum wire produced by conventional low-speed drawing technology.

[0048] Reference numerals:

[0049] 100 drawn wire 200 heatless multi-mode drawing die 300 graphite emulsion coating area

[0050] 400 heating zone 500 hot drawing multi-mode serial drawing die 600 oil inlet pipe

[0051] 700 oil tank 800 oil outlet pipe 900 radiator DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments; the technical features designed in different implementation modes of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0053] In the description of the present invention, it should be noted that all terms used in the present invention (including technical terms and scientific terms) have the same meanings as those generally understood by ordinary technicians in the field to which the present invention belongs, and should not be understood as limiting the present invention; it should be further understood that the terms used in the present invention should be understood to have meanings consistent with the meanings of these terms in the context of this specification and in the relevant fields, and should not be understood in an idealized or overly formal sense, unless explicitly defined as such in the present invention.

[0054] The high-speed cold-drawing method for preparing wire-cut molybdenum wire provided by the present invention can be applied to the production of composite-doped wire-cut molybdenum wire with a high rare earth oxide content. Due to the high rare earth oxide content, conventional cold-drawing processes for composite-doped wire-cut molybdenum wire are prone to breakage, making production impossible. The high-speed cold-drawing method for preparing wire-cut molybdenum wire provided by the present invention can improve both the yield and quality of composite-doped wire-cut molybdenum wire while simultaneously achieving efficient production.

[0055] The preliminary preparation steps of molybdenum alloy wire rod for high rare earth oxide content composite doped wire cutting molybdenum wire are as follows:

[0056] Molybdenum powder and rare earth oxide are doped in a set ratio to prepare a uniform powder, which is then isostatically pressed and sintered, and then cooled in the furnace to obtain a molybdenum alloy billet;

[0057] The sintered molybdenum alloy billet is hot-rolled in a two-roll rolling mill to form a molybdenum alloy wire rod;

[0058] The molybdenum alloy wire rod is then subjected to at least one swaging and at least one hot drawing process to produce a drawn wire. Lanthanum oxide or cerium oxide is used as the rare earth oxide. The hot drawing process includes coarse-gauge hot drawing and multi-mode hot drawing. Furthermore, according to existing techniques, graphite emulsion is applied before each coarse-gauge hot drawing and multi-mode hot drawing process. The surface of the drawn wire obtained after die drawing has a compacted graphite emulsion coating. The specific graphite emulsion ratio can be determined based on actual conditions and is not limited.

[0059] The molybdenum alloy wire rods in the following examples and comparative examples were prepared according to this process flow.

[0060] Example 1

[0061] Drawing 7500ppm lanthanum content wire cutting molybdenum wire

[0062] A1. Prepare a molybdenum alloy wire rod having a lanthanum content of 7500 ppm according to the process flow; process the molybdenum alloy wire rod by coarse hot drawing and hot drawing multi-mode string drawing at a hot drawing temperature of 700° C. to obtain drawn wire.

[0063] A2. A layer of graphite emulsion solution is applied to the surface of the drawn wire, and the solution is dried at a linear speed of 40 m / min in a heating zone at 750° C. and a length of 500 mm to prepare a dried graphite emulsion coating;

[0064] A3. The drawn wire obtained in A2 is subjected to high-speed cold drawing at room temperature. It is lubricated with a special drying graphite emulsion coating, and then the mold is cooled with vegetable oil. The coating thickness is 2.5 μm, the oil temperature is 40°C, the cold drawing speed is 380 m / min, and the deformation per cold drawing pass is 18%.

[0065] The graphite emulsion solution used in this embodiment can be prepared with the original graphite emulsion colloid produced by conventional manufacturers on the market. The relevant indicators of the graphite emulsion solution can be referred to Table 1. According to the ratio of the original graphite emulsion colloid to water of 1:4, after sufficient stirring, its approximate specific gravity range is 1.0-1.06 g / cm 3 Then, the prepared graphite emulsion solution is used as the preliminary material for preparing the dried graphite emulsion coating to coat the surface of the drawn wire. The surface state of the wire with the dried graphite emulsion coating is as follows: Figure 2 As shown; Figure 3 As shown, the coating thickness is 2 to 5 μm and the C content is 1200 to 3000 ppm.

[0066] Table 1 Graphite emulsion solution related indicators

[0067]

[0068] The composite doped wire-cut molybdenum wire prepared in this embodiment is as follows: Figure 4 The metallographic structure shown is dense, with no deep grooves and microcracks on the surface, the crack grade is A0, and the mold yield is 62,000 meters / hole.

[0069] Example 2

[0070] Drawing Wire-cut Molybdenum Wire with 18000ppm Lanthanum Content

[0071] B1. Prepare a molybdenum alloy wire rod with a lanthanum content of 18,000 ppm according to the process flow; process the molybdenum alloy wire rod by coarse hot drawing and hot drawing multi-mode string drawing at a hot drawing temperature of 700° C. to obtain a drawn wire.

[0072] B2, coating the surface of the drawn wire with a layer of graphite emulsion solution, and drying the solution in a heating zone at 750° C. and a length of 500 mm at a linear speed of 35 m / min to prepare a dried graphite emulsion coating;

[0073] B3, the drawn wire obtained in B2 is subjected to high-speed cold drawing at room temperature, lubricated with a drying graphite emulsion coating with a thickness of 3 μm, and then cooled with vegetable oil at a temperature of 37°C. The cold drawing speed is 260 m / min, and the deformation per cold drawing pass is 18%;

[0074] The remaining process parameters are the same as those in Example 1.

[0075] The composite doped wire-cut molybdenum wire prepared in this embodiment is as follows: Figure 5 The metallographic structure shown is dense, with no deep grooves and microcracks on the surface, the crack grade is A1, and the mold yield is 52,000 meters / hole.

[0076] Example 3

[0077] Drawing 8000ppm cerium content wire-cut molybdenum wire

[0078] C1. Prepare a molybdenum alloy wire rod with a cerium content of 8000 ppm according to the process flow; process the molybdenum alloy wire rod by coarse-gauge hot drawing and hot-drawing multi-mode string drawing at a hot drawing temperature of 700° C. to obtain a drawn wire.

[0079] C2. Coating a layer of graphite emulsion solution on the surface of the drawn wire and drying the solution in a heating zone at 750° C. and 500 mm in length at a linear speed of 45 m / min to prepare a dried graphite emulsion coating;

[0080] C3. The drawn wire obtained in C2 is subjected to high-speed cold drawing at room temperature, lubricated with a special drying graphite emulsion coating, and then cooled with vegetable oil. The coating thickness is 2.5 μm, the oil temperature is 40°C, the cold drawing speed is 380 m / min, and the deformation per cold drawing pass is 18%.

[0081] The remaining process parameters are the same as those in Example 1.

[0082] The composite doped wire-cut molybdenum wire prepared in this embodiment is as follows: Figure 6 The metallographic structure shown is dense, with no deep grooves and microcracks on the surface, the crack grade is A0, and the mold yield is 65,000 meters / hole.

[0083] Example 4

[0084] Drawing 18000ppm cerium content wire-cut molybdenum wire

[0085] D1. Prepare a molybdenum alloy wire rod with a cerium content of 18,000 ppm according to the process flow; process the molybdenum alloy wire rod by coarse hot drawing and hot drawing multi-mode string drawing at a hot drawing temperature of 700° C. to obtain drawn wire.

[0086] D2. A layer of graphite emulsion solution is coated on the surface of the drawn wire, and dried in a heating zone at 750°C and 500 mm in length at a linear speed of 37 m / min to prepare a special graphite emulsion coating;

[0087] D3. The drawn wire obtained in D2 is subjected to high-speed cold drawing at room temperature. It is lubricated with a special drying graphite emulsion coating, and then the mold is cooled with vegetable oil. The coating thickness is 2.5 μm, the oil temperature is 40°C, the cold drawing speed is 260 m / min, and the deformation per cold drawing pass is 18%.

[0088] The remaining process parameters are the same as those in Example 1.

[0089] The composite doped wire-cut molybdenum wire prepared in this embodiment is as follows: Figure 7 The metallographic structure shown is dense, with no deep grooves and microcracks on the surface, the crack grade is A2, and the mold yield is 52,000 meters / hole.

[0090] Comparative Example 1

[0091] The difference between Comparative Example 1 and Example 1 is that the cold drawing process used after hot drawing is prepared by the high-speed cold drawing preparation technology of plastic metal materials commonly used in other industries (i.e., full immersion liquid lubrication drawing, commonly known as water tank drawing technology), and the remaining steps and process parameters are the same.

[0092] The composite doped wire-cut molybdenum wire prepared in Comparative Example 1 has a metallographic structure as shown in FIG. Figure 8 As shown in the figure, there are obvious cracks on the surface of the wire. Figure 9 As shown, deep grooves appeared, crack grade C, mold loss was large, and mold production was 7,000 meters / hole.

[0093] In Comparative Example 1, the high-speed cold drawing preparation technology of plastic metal materials commonly used in other industries is directly adopted. Since the wire drawing wheel is fully immersed in lubricating oil, and the wire needs to be wound around the wheel during the drawing process, the graphite emulsion coating on the surface of the wire is easily damaged under the action of lubricating oil. Figure 10 and Figure 11 As shown, since molybdenum wire is a difficult-to-deform metal, during its cold drawing process, the lubricating liquid cannot smoothly enter the compression area and sizing area of the die hole. Therefore, it needs to rely on the graphite emulsion coating with a certain film-forming strength on its surface for lubrication. Once the graphite emulsion coating is damaged, the liquid lubricating oil cannot play a lubricating role. Therefore, dry friction is formed between the molybdenum wire and the die, which makes the die easily damaged.

[0094] Comparative Example 2

[0095] The difference between Comparative Example 2 and Example 1 is that the drawn wire obtained in Step A1 is directly subjected to high-speed cold drawing in Step A3 without Step A2, and the remaining steps and process parameters are the same.

[0096] The composite doped wire-cut molybdenum wire prepared in Comparative Example 2 has a metallographic structure as shown in FIG. Figure 12 As shown in the figure, there are obvious cracks on the surface of the wire. Figure 13 As shown, deep grooves appeared, crack grade B, mold loss was large, and mold production was 27,000 meters / hole.

[0097] Comparative Example 2 Actual process is as follows Figure 14 As shown in the figure, only the compacted graphite emulsion coating commonly used in the cold drawing process of the molybdenum wire industry is used for lubrication, that is, the graphite emulsion coating is not dried after the last pass of the hot drawing multi-mode series drawing. The surface of the wire obtained after the last pass of the hot drawing multi-mode series drawing is as follows: Figure 15 As shown. Figure 16 As shown in the figure, the graphite emulsion coating on the surface of the wire is less than 2μm thick and contains less than 1200ppm of carbon. Using the graphite emulsion coating for lubrication, the average mold production level is 34,800 meters per hole. The drawn wire surface has obvious deep grooves, and its laser flaw detection drawing is as follows: Figure 17 As shown, it shows that after multiple cold drawing passes, the obtained wire has dense cracks.

[0098] The results of the implementation of Examples 1 to 4 and Comparative Examples 1 to 2 are as follows:

[0099] The doping test components of Examples 1 to 4 and Comparative Examples 1 to 2 are shown in Table 2.

[0100] Table 2 Comprehensive evaluation table of doping test

[0101]

[0102] Note: Figure 18 This is a crack detection measurement pattern diagram. The crack grade is divided into three levels based on the PPM value of the 15% alarm threshold: A material: <2000; B material: 2000-10000; C material and above: >10000. Among them, the crack grade of A material is divided into three levels: A0: <1000; A1: 1000-1500; A2: 1500-2000, as shown in Table 3 below:

[0103] Table 3 Definition of crack levels of φ0.18mm molybdenum wire products after eddy current testing

[0104]

[0105]

[0106] At the same time, based on Example 1, the influence of the oil cooling process on the high-speed drawing technology was further studied:

[0107] The dried graphite emulsion coating of Example 1 is used as the base lubricant, and the wire is oiled through the vegetable oil circulation tank and brought into the cold drawing die for die temperature reduction processing. Vegetable oil has a special temperature control device, such as Figure 19 As shown: After the vegetable oil is extracted from the oil tank, it passes through the oil outlet pipe and the radiator to cool the oil temperature. By controlling the heat exchange capacity of the radiator, the oil temperature can be controlled and freely adjusted between 25 and 50 degrees Celsius.

[0108] Table 4 below shows the lubricant and die temperature variations over drawing time with and without a temperature control device. The lubricant temperature can be effectively reduced by 13°C, and the die temperature by approximately 20°C. With the temperature control device, the cold drawing die production reached 56,000 meters per hole, while without the device, it was only 35,000 meters per hole.

[0109] Table 4 Variation of lubricating fluid temperature and corresponding die temperature with drawing time when using temperature control device and not using temperature control device

[0110]

[0111] As can be seen from Table 4, the present invention can achieve a cold-drawn molybdenum wire speed of 260-400 m / min and a cold-drawing deformation of 10-25% by adopting the technology of drying the graphite emulsion coating and cooling the mold temperature with oil.

[0112] At the same time, the products obtained by Example 1 and the low-speed cold drawing technology are further compared, that is, steps A2 and A3 are replaced by the existing conventional low-speed cold drawing technology.

[0113] The product obtained in Example 1 is as follows Figure 20 As shown in the figure, the structure is dense and the surface hardness is high. However, the molybdenum wire prepared by conventional low-speed cold drawing technology not only has low production efficiency, but also has high Figure 21 As shown in Table 5, the average diameter uniformity (CP value) of the product obtained in Example 1 is higher than that of the molybdenum wire prepared by conventional low-speed cold drawing technology.

[0114] Table 5 Comparison of diameter uniformity and hardness of two technologies

[0115]

[0116] In summary, the high-speed cold-drawing method for preparing wire-cut molybdenum wire provided by the present invention can be applied to the preparation of composite-doped wire-cut molybdenum wire with a high rare earth oxide content, achieving high production efficiency and low cost. It can also effectively improve various performance indicators of the resulting composite-doped wire-cut molybdenum wire.

[0117] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present invention may be improved in only one or several aspects, without having to simultaneously solve all the technical problems listed in the prior art or background art. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as limiting the claim.

[0118] Although terms such as molybdenum alloy wire rod and drawn wire are frequently used herein, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention. The terms "first," "second," and so on (if any) in the description and claims of the embodiments of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a wire-cut molybdenum wire by high-speed cold drawing, characterized in that: Here are the steps: S1. hot-drawing the molybdenum alloy wire rod in coarse gauge and hot-drawing multi-mode series to obtain drawn wire; S2, coating a graphite emulsion solution on the surface of the drawn wire, and then drying the drawn wire to obtain the drawn wire with a dried graphite emulsion coating attached to the surface; S3, passing the drawn wire with the dried graphite emulsion coating through a vegetable oil circulation tank to be oiled and then entering a cold drawing die for high-speed cold drawing to obtain a wire-cut molybdenum wire; The drying process is to coat the drawn wire with the graphite emulsion solution and then dry it in a heating zone at a speed of 30 to 50 m / min at a temperature of 600 to 800° C. and a length of 400 to 900 mm. The thickness of the dried graphite emulsion coating is 2-5 μm and the carbon content is 1200-3000 ppm.

2. The method for preparing a wire-cut molybdenum wire at a high speed by cold drawing according to claim 1, wherein: The graphite emulsion solution includes graphite emulsion and water; the weight ratio of the graphite emulsion to water is 1:

4.

3. The method for preparing a wire-cut molybdenum wire at a high speed by cold drawing according to claim 2, wherein: The specific gravity of the graphite emulsion solution is 1.0 to 1.06 g / cm 3 .

4. The method for preparing a wire-cut molybdenum wire at a high speed by cold drawing according to claim 1, wherein: The oil temperature in the vegetable oil circulation tank is 25-40°C.

5. The method for preparing a wire-cut molybdenum wire at a high speed by cold drawing according to claim 4, wherein: The vegetable oil circulation tank is provided with a temperature control device.

6. The method for preparing a wire-cut molybdenum wire at a high speed by cold drawing according to claim 1, wherein: The high-speed cold drawing process has a drawing speed of 260 to 400 m / min.

7. The method for preparing a wire-cut molybdenum wire at a high speed by cold drawing according to claim 6, wherein: The high-speed cold drawing process includes at least three cold drawing passes.

8. The method for preparing a wire-cut molybdenum wire at a high speed by cold drawing according to claim 7, wherein: The deformation of each cold drawing pass is 10-25%.

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