A phosphorus deoxidized copper material, a preparation method and application thereof

Abstract

This invention discloses a phosphorus-deoxidized copper material, its preparation method, and its application. The preparation method of the phosphorus-deoxidized copper material includes the following steps: (1) continuously casting the raw material to obtain a billet; wherein the raw material includes a phosphorus-copper master alloy and metallic copper; (2) continuously extruding the billet to obtain a profile; wherein the extrusion temperature of the continuous extrusion is 400-550℃; the rated speed range of the continuous extrusion is 5-15 r / MP; (3) cold drawing, heat treatment, and machining of the profile. The preparation method of this invention effectively improves the material utilization rate, and the obtained phosphorus-deoxidized copper material has good mechanical and electrical properties, as well as good material consistency and density.

Description

Technical Field

[0001] This invention relates to a phosphorus-deoxidized copper material, its preparation method, and its application. Background Technology

[0002] In recent years, with the rapid development of rail transit and the rapid advancement of AC drive technology, asynchronous traction motors have become more widely used. Asynchronous motors are characterized by their simple structure, reliable components, and superior electromagnetic performance, making them suitable for electric locomotives, multiple units (MMUs), and diesel locomotives. The motor rotor is the core component of the asynchronous traction motor, converting electrical energy into kinetic energy through electromagnetic interaction to power the entire locomotive (high-speed rail, subway, etc.). Because pure copper possesses excellent electrical and thermal conductivity, corrosion resistance, and good machinability, it can be used as rotor bars for lower power and lower speeds; however, pure copper conductor bars have relatively low strength.

[0003] To further improve the mechanical properties and welding quality of the end ring conductor, a small amount of phosphorus is added to the copper without significantly reducing its conductivity. This increases the fluidity of the molten material and improves its welding performance. Phosphorus-deoxidized copper rotor conductors, as an important component of asynchronous traction motor rotors, have become one of the high-performance copper alloy conductors used in rail transit traction motors due to their excellent electrical and thermal conductivity, high strength, and brazing performance.

[0004] Currently, the manufacturing process of phosphorus-deoxidized copper conductor bars for squirrel-cage motor rotors involves obtaining ingots through induction melting, followed by hot extrusion (water sealing), cold drawing deformation, stress-relief heat treatment, and machining to produce the phosphorus-deoxidized copper conductor bars. However, the induction melting process is intermittent, resulting in low production efficiency and material utilization. Furthermore, the conductor bar profiles produced by hot extrusion suffer from uneven deformation during the process, leading to poor mechanical properties and inconsistent metallographic structure, and high energy consumption. The surface quality of the hot-extruded profiles is unstable, with numerous defects such as inclusions, peeling, and extrusion marks, requiring complex processing and impacting product quality. Additionally, the tail of the profiles produced by hot extrusion inevitably produces shrinkage defects, which can only be minimized through processing, not completely eliminated. The presence of shrinkage defects disrupts the material's density and continuity, severely affecting its performance; these defects are generally removed through visual inspection and ultrasonic testing. However, due to the irregularity and instability of defects, there are blind spots in detection, and there is a risk of not being identified. Furthermore, the defects cannot be pressed together in subsequent processing, which poses a certain quality risk to the product and may cause economic losses to the company.

[0005] Therefore, in order to improve the mechanical and electrical properties, material consistency, density, and material utilization of phosphorus deoxidized copper conductors, it is urgent to provide a phosphorus deoxidized copper material and its preparation method. Summary of the Invention

[0006] The problem this invention aims to solve is to overcome the defects of phosphorus deoxidized copper conductors prepared by existing methods, such as poor uniformity and density, low material utilization, and poor mechanical and electrical properties. This invention provides a phosphorus deoxidized copper material, its preparation method, and its applications. The preparation method of this invention effectively improves material utilization, and the resulting phosphorus deoxidized copper material exhibits better mechanical and electrical properties, as well as better uniformity and density.

[0007] The present invention solves the above-mentioned technical problems through the following technical solutions:

[0008] This invention provides a method for preparing phosphorus-deoxidized copper material, which includes the following steps:

[0009] (1) The raw materials are subjected to continuous casting to obtain billets; wherein the raw materials include phosphorus-copper master alloy and metallic copper;

[0010] (2) The billet is subjected to continuous extrusion to obtain a profile; wherein the extrusion temperature of the continuous extrusion is 400-550℃; and the rated speed range of the continuous extrusion is 5-15 r / MP.

[0011] (3) The profile is subjected to cold drawing, heat treatment and machining.

[0012] In step (1), the metallic copper can be oxygen-free copper.

[0013] The metallic copper may be in the form of a copper rod; preferably, it is an oxygen-free copper rod. The diameter of the copper rod is preferably 8–12 mm.

[0014] The content of the phosphorus-copper master alloy in the raw material can be 0.01-0.4 wt%; preferably 0.01-0.1 wt%; more preferably 0.0134-0.035 wt%; the balance is metallic copper; the percentage is the mass percentage of the phosphorus-copper master alloy or the metallic copper in the raw material.

[0015] The phosphorus-copper master alloy preferably includes phosphorus and copper; the phosphorus content is preferably 10-20 wt%, with the balance being copper; the percentage is the mass percentage of phosphorus or copper in the phosphorus-copper master alloy.

[0016] The metallic copper preferably includes copper and oxygen; the content of copper is preferably 99.97 wt% or more, and the content of oxygen is preferably 0.0005 wt% or less; the percentage is the mass percentage of copper or oxygen in the metallic copper.

[0017] In step (1), the upward continuous casting process can be carried out in an inert atmosphere; the inert atmosphere is preferably an argon atmosphere.

[0018] The crucible used in the upward continuous casting process can be a graphite crucible.

[0019] The temperature of the upward continuous casting process can be 1100-1200℃, preferably 1110-1150℃, and more preferably 1120℃.

[0020] The upward speed of the continuous casting process can be 800-1500 mm / min, preferably 850-1300 mm / min, and more preferably 900-1200 mm / min.

[0021] The billet can be cylindrical. The diameter of the billet is preferably 20-30 mm. Generally, each roll of billet weighs 3-5 tons.

[0022] The oxygen content of the billet is preferably below 5 ppm; more preferably 3 to 4 ppm. The phosphorus content of the billet is preferably 0.002 to 0.06 wt%; more preferably 0.007 to 0.04 wt%; and even more preferably 0.01 to 0.02 wt%. The balance is copper.

[0023] In step (2), the extrusion temperature of the continuous extrusion process is preferably 400-550°C, more preferably 450-500°C.

[0024] The rated speed range of the continuous extrusion process is preferably 5 to 15 r / MP, more preferably 8 to 12 r / MP, and even more preferably 10 r / MP.

[0025] The equipment for the continuous extrusion process can be conventional in the art, such as a continuous extrusion press for copper.

[0026] The die used for the continuous extrusion process can be conventional in the field and can generally be selected or designed according to the product cross-section requirements.

[0027] Following the continuous extrusion process, a water cooling step is typically included, as is customary in the art.

[0028] In step (3), the cold drawing process can be conventional in the field, and generally involves drawing the profile through multiple passes.

[0029] The number of cold drawing processes can be 1 to 5 times, preferably 2 to 3 times.

[0030] The cumulative drawing deformation of the cold drawing process can be 10-40%, preferably 15-35%.

[0031] The deformation amount of a single drawing in the cold drawing process can be 5% to 15%, preferably 8% to 15%.

[0032] The drawing speed of the cold drawing process can be 200-400 mm / s, preferably 250-350 mm / s; more preferably 300 mm / s.

[0033] After the cold drawing process, according to conventional practice in the art, a step of sawing to a fixed length may be included to obtain a guide bar semi-finished product.

[0034] In step (3), the heat treatment can be conventional in the art, such as stress-relief annealing. The temperature of the stress-relief annealing is 250–350°C; preferably 300°C. The stress-relief annealing temperature can be maintained for 1–2 hours; preferably 1.5 hours.

[0035] In step (3), the machining process can be conventional in the field, and generally can be to process the guide bar according to the product drawings to obtain phosphorus deoxidized copper material that meets the dimensional tolerance requirements.

[0036] The present invention also provides a phosphorus-deoxidized copper material prepared by the above method. The phosphorus-deoxidized copper material is generally a phosphorus-deoxidized copper conductor strip.

[0037] This invention also provides an application of phosphorus-deoxidized copper material as a guide bar in the squirrel-cage rotor of an asynchronous motor.

[0038] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0039] The reagents and raw materials used in this invention are all commercially available.

[0040] The positive and progressive effects of this invention are as follows:

[0041] 1. The preparation method of phosphorus deoxidized copper material in this invention effectively improves the material utilization rate from 60% in the original process to over 73%, while also improving quality stability and reducing energy consumption.

[0042] 2. The phosphorus deoxidized copper material prepared by this invention has good mechanical and electrical properties, good material consistency and density, uniform composition and low oxygen content; and the profile surface is smooth and bright, without inclusions, peeling and other defects, and the profile deformation is uniform and without tail shrinkage defects. Detailed Implementation

[0043] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0044] Preparation of phosphorus-deoxidized copper conductors in Examples 1-3

[0045] (1) The raw materials are subjected to continuous casting to obtain billets; wherein the raw materials include phosphorus-copper master alloy and oxygen-free copper rod; the mass percentage of phosphorus-copper master alloy and oxygen-free copper rod, the composition of phosphorus-copper master alloy, the composition and diameter of oxygen-free copper rod, the composition of billet, and the process parameters of continuous casting are shown in Table 1.

[0046] (2) The billet is subjected to continuous extrusion to obtain the profile; wherein the extrusion temperature and rated speed range of the continuous extrusion are shown in Table 1.

[0047] (3) The profile is subjected to cold drawing, stress relief annealing heat treatment and machining treatment; the process parameters of cold drawing and stress relief annealing heat treatment are shown in Table 1.

[0048] Table 1

[0049]

[0050]

[0051] Comparative Example 1: Preparation of Phosphorus Deoxidized Copper Conductor

[0052] In Comparative Example 1, step (1) involves continuous casting to obtain phosphorus-deoxidized copper ingots (round ingots), and the ingots are hot-extruded to obtain phosphorus-deoxidized copper profiles; all other steps are the same as in Example 1.

[0053] Effect Example

[0054] 1. Calculate the material utilization rate in the above embodiments and comparative examples, as shown in Table 2.

[0055] The calculation method is as follows: Material utilization rate = (feed weight - output weight) / feed weight * 100%. Wherein, feed weight refers to the weight of raw materials, and output weight refers to the weight of the phosphorus deoxidized copper conductor strip produced.

[0056] Table 2

[0057]

[0058]

[0059] As shown in the table above, the material utilization rate of the preparation methods for phosphorus deoxidized copper materials in Examples 1-3 is over 73%, while that in Comparative Example 1 is only 60%. This demonstrates that the preparation method in this application effectively improves the material utilization rate by more than 10% compared to Comparative Example 1; simultaneously, it also improves quality stability and reduces energy consumption.

[0060] 2. Take three samples of phosphorus-deoxidized copper conductors prepared in Examples 1-3 and Comparative Example 1 respectively, and test their oxygen content according to the method of GB / T5121.8-2008; test their phosphorus content according to the method of GB / T 5121.2-2008.

[0061] The test results are shown in Table 3 below.

[0062] Table 3

[0063]

[0064] 3. Take three samples of phosphorus deoxidized copper conductors prepared in Examples 1-3 and Comparative Example 1 respectively, and test their mechanical and electrical properties.

[0065] The conductivity was obtained according to the method of YS / T 478.

[0066] The tensile strength was tested according to the method in GB / T 228.1.

[0067] The average grain size was obtained according to the method of YS / T 347.

[0068] The test results are shown in Table 4 below.

[0069] Table 4

[0070]

[0071] The test results above show that the phosphorus deoxidized copper material conductors prepared in Examples 1 to 3 have good mechanical and electrical properties, good material consistency and density, uniform composition and low oxygen content; and the profile surface is smooth and bright, without inclusions, peeling and other defects, and the profile deformation is uniform and without tail shrinkage defects.

Claims

1. A method for preparing a phosphorus-deoxidized copper material, characterized in that, It includes the following steps: (1) The raw materials are subjected to continuous casting to obtain billets; wherein the raw materials include phosphorus-copper master alloy and metallic copper; The content of the phosphorus-copper master alloy is 0.01~0.4wt%; the balance is metallic copper; the percentage is the mass percentage of the phosphorus-copper master alloy or the metallic copper in the raw material; The phosphorus-copper master alloy includes phosphorus and copper; the phosphorus content is 10~20 wt%, and the balance is copper; the percentage is the mass percentage of phosphorus or copper in the phosphorus-copper master alloy. The upward continuous casting process is carried out in an inert atmosphere; the upward speed of the upward continuous casting process is 800~1500 mm / min; (2) The billet is subjected to continuous extrusion to obtain a profile; wherein the extrusion temperature of the continuous extrusion is 400~550℃; and the rated speed range of the continuous extrusion is 5~15rpm. (3) The profile is subjected to cold drawing, heat treatment and machining; the drawing speed of the cold drawing is 200~400mm / s.

2. The method for preparing phosphorus-deoxidized copper material as described in claim 1, characterized in that, In step (1), the metallic copper is oxygen-free copper; And / or, the copper metal is in the form of a copper rod.

3. The method for preparing phosphorus-deoxidized copper material as described in claim 2, characterized in that, In step (1), the diameter of the copper rod is 8~12mm.

4. The method for preparing phosphorus-deoxidized copper material as described in claim 1 or 2, characterized in that, In step (1), the content of the phosphorus-copper master alloy in the raw materials is 0.01~0.1 wt%.

5. The method for preparing phosphorus-deoxidized copper material as described in claim 4, characterized in that, In step (1), the content of the phosphorus-copper master alloy in the raw materials is 0.0134~0.035wt%.

6. The method for preparing phosphorus-deoxidized copper material as described in claim 4, characterized in that, In step (1), the raw material, the metallic copper, includes copper and oxygen elements.

7. The method for preparing phosphorus-deoxidized copper material as described in claim 6, characterized in that, In step (1), the content of copper element in the raw material is 99.97 wt% or more; the percentage is the mass percentage of copper element in the metallic copper.

8. The method for preparing phosphorus-deoxidized copper material as described in claim 6, characterized in that, In step (1), the oxygen content in the raw material is less than 0.0005 wt%; the percentage is the mass percentage of oxygen in the copper metal.

9. The method for preparing phosphorus-deoxidized copper material as described in claim 1, characterized in that, In step (1), the inert atmosphere is an argon atmosphere; And / or, the crucible in the upward continuous casting process is a graphite crucible; And / or, the temperature of the upward continuous casting process is 1100~1200℃.

10. The method for preparing phosphorus-deoxidized copper material as described in claim 9, characterized in that, In step (1), the temperature of the upward continuous casting process is 1110~1150℃.

11. The method for preparing phosphorus-deoxidized copper material as described in claim 9, characterized in that, In step (1), the temperature of the upward continuous casting process is 1120℃.

12. The method for preparing phosphorus-deoxidized copper material as described in claim 1, characterized in that, In step (1), the upward speed of the continuous casting process is 850~1300 mm / min; And / or, the blank is cylindrical in shape; And / or, the oxygen content of the billet is below 5 ppm.

13. The method for preparing phosphorus-deoxidized copper material as described in claim 12, characterized in that, In step (1), the upward speed of the continuous casting process is 900~1200 mm / min; And / or, the diameter of the blank is 20~30mm; And / or, the oxygen content of the billet is 3~4 ppm.

14. The method for preparing phosphorus-deoxidized copper material as described in claim 12, characterized in that, In step (1), the upward speed of the continuous casting process is 1000 mm / min; And / or, the phosphorus content of the billet is 0.002~0.06 wt%, with the balance being copper.

15. The method for preparing phosphorus-deoxidized copper material as described in claim 12, characterized in that, In step (1), the phosphorus content of the billet is 0.007~0.04 wt%, and the balance is copper.

16. The method for preparing phosphorus-deoxidized copper material as described in claim 12, characterized in that, In step (1), the phosphorus content of the billet is 0.01~0.02 wt%, and the balance is copper.

17. The method for preparing phosphorus-deoxidized copper material as described in claim 1, characterized in that, In step (2), the extrusion temperature of the continuous extrusion process is 400~550℃; And / or, the rated speed range of the continuous extrusion process is 5~15 rpm.

18. The method for preparing phosphorus-deoxidized copper material as described in claim 17, characterized in that, In step (2), the extrusion temperature of the continuous extrusion process is 450~500℃; And / or, the rated speed range of the continuous extrusion process is 8~12 rpm.

19. The method for preparing phosphorus-deoxidized copper material as described in claim 17, characterized in that, In step (2), the rated speed range of the continuous extrusion process is 10 rpm.

20. The method for preparing phosphorus-deoxidized copper material as described in claim 1, characterized in that, In step (3), the cold drawing process involves drawing the profile through multiple passes. The number of cold drawing processes is 1 to 5. And / or, the cumulative drawing deformation of the cold drawing process is 10-40%; And / or, the single-drawing deformation amount of the cold drawing treatment is 5~15%; And / or, the drawing speed of the cold drawing process is 250~350mm / s.

21. The method for preparing phosphorus-deoxidized copper material as described in claim 20, characterized in that, In step (3), the cold drawing process is performed 2 to 3 times; And / or, the cumulative drawing deformation of the cold drawing process is 15-35%; And / or, the single-drawing deformation amount of the cold drawing process is 8~15%; And / or, the drawing speed of the cold drawing process is 300 mm / s.

22. The method for preparing phosphorus-deoxidized copper material as described in claim 20, characterized in that, In step (3), the cumulative drawing deformation of the cold drawing process is 20-30%; And / or, the single-drawing deformation amount of the cold drawing process is 10%.

23. The method for preparing phosphorus-deoxidized copper material as described in claim 1, characterized in that, In step (3), the heat treatment is stress-relief annealing heat treatment.

24. The method for preparing phosphorus-deoxidized copper material as described in claim 23, characterized in that, In step (3), the temperature of the stress-relief annealing heat treatment is 250~350℃.

25. The method for preparing phosphorus-deoxidized copper material as described in claim 23, characterized in that, In step (3), the temperature of the stress-relief annealing heat treatment is 300°C.

26. The method for preparing phosphorus-deoxidized copper material as described in claim 23, characterized in that, In step (3), the stress-relief annealing heat treatment is carried out at a temperature of 1-2 hours.

27. The method for preparing phosphorus-deoxidized copper material as described in claim 23, characterized in that, In step (3), the stress-relief annealing heat treatment is carried out at a temperature of 1.5 h.

28. A phosphorus-deoxidized copper material, characterized in that, The phosphorus-deoxidized copper material is prepared by the preparation method described in any one of claims 1 to 27.

29. The application of the phosphorus deoxidized copper material as described in claim 28 as a guide bar in the squirrel cage rotor of an asynchronous motor.

Images