A copper-zirconium intermediate alloy cored pipe, a preparation method and application thereof

Abstract

The application belongs to the technical field of copper alloy, and particularly relates to a copper-zirconium intermediate alloy cored pipe and a preparation method and application thereof. The copper-zirconium intermediate alloy cored pipe comprises an inner core and a cladding layer. The cladding layer is a T2 copper pipe, and the inner core is copper-zirconium intermediate alloy particles with a particle size of less than or equal to 1.0 mm. The copper-zirconium intermediate alloy cored wire has a low melting point, high reliability, and uniform and dense distribution of copper-zirconium intermediate alloy particles in the cored wire without air residues. When used for non-vacuum smelting to manufacture copper-zirconium alloy, the copper-zirconium intermediate alloy cored wire has a fast melting speed, uniformly distributes and flows into a crystallizer to be cast into a cast blank, can reduce the oxidation loss of zirconium, and can realize large-scale production.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of copper alloy, and particularly relates to a copper-zirconium intermediate alloy cored pipe and a preparation method and application thereof. BACKGROUND

[0002] The copper-chromium-zirconium alloy has good electrical conductivity, thermal conductivity, high hardness, wear resistance, explosion resistance, corrosion resistance, crack resistance and softening temperature and the like. The material is widely applied in the fields of electrode material of automatic welding machine for automobile, large-scale integrated circuit, contact wire of high-speed train, switch contact bridge and continuous casting steel crystallizer and the like. In recent years, the demand for clean energy rapidly increases, and the copper-chromium-zirconium alloy is also widely applied in the fields of electrolytic copper foil, solar photovoltaic panel, lithium battery and the like. In the future, with the continuous expansion of the new energy market, the application of the copper-chromium-zirconium alloy in the new energy field will be further increased. Therefore, the copper-chromium-zirconium alloy industry is expected to have a broader development prospect in the future. However, the production technology of the copper-chromium-zirconium alloy is difficult, mainly because the affinity of chromium and zirconium with oxygen is extremely strong under the condition of high-temperature smelting and casting, and the chromium and zirconium are extremely easy to oxidize and volatilize in the smelting and casting process, resulting in uneven composition. Generally, the vacuum smelting and casting method needs to be used to reduce oxidation and volatilization, so as to ensure that the product finally has the required chemical composition. However, due to the structure of the vacuum induction furnace, the production mode is limited to products with periodic operation, and the weight or length of single casting is limited by the crucible capacity, and products with large weight or theoretically infinite length cannot be produced, and the production cost is high. By using non-vacuum casting, products with large weight or theoretically infinite length can be produced, but the problem of difficult composition control under non-vacuum needs to be solved. For example, the zirconium in the copper-zirconium intermediate alloy is easy to be oxidized or the particles are easy to be leaked, and the solidification of copper liquid caused by temperature drop in the runner, which to some extent makes the composition unstable under non-vacuum, and affects the production.

[0003] Therefore, it is necessary to develop a copper-zirconium intermediate cored pipe which can reduce the oxidation loss of zirconium and realize large-scale production, and is used for non-vacuum smelting to manufacture copper-zirconium alloy. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a copper-zirconium intermediate alloy cored pipe and a preparation method and application thereof. The copper-zirconium intermediate alloy cored wire has low melting point, high reliability, uniform and dense distribution of copper-zirconium intermediate alloy particles in the cored wire, no air residue, fast melting speed when used for non-vacuum smelting to manufacture copper-zirconium alloy, uniform distribution and flow into the crystallizer to be cast into a casting blank, which not only can reduce the oxidation loss of zirconium, but also can realize large-scale production.

[0005] To address the technical problem presented in this invention, a copper-zirconium master alloy cored tube is provided, comprising an inner core and a cladding layer. The cladding layer is a T2 copper tube, and the inner core consists of copper-zirconium master alloy particles with a particle size ≤1.0 mm, free from unalloyed or insufficiently alloyed elements. This technical solution controls the particle size of the copper-zirconium master alloy particles and removes unalloyed or insufficiently alloyed elements. After processing into a copper-zirconium master alloy cored tube, the copper-zirconium master alloy particles inside the copper tube meet the requirements of being dense, uniform, free from other impurities, and essentially free of air residue. This accelerates the melting rate, significantly reduces zirconium oxidation loss, and ensures uniform addition, thereby improving the quality of subsequent copper casting.

[0006] Furthermore, the zirconium content in the copper-zirconium master alloy particles is 45-55%. This invention selects a copper-zirconium master alloy with a zirconium content of 45-55% as the copper-zirconium alloy source. Its melting point is ≤950℃. After being fed into the molten copper in the casting tank, it immediately melts and is evenly distributed within the molten copper. Then, it gradually flows into the crystallizer within a short time to be cast into a billet. This greatly reduces the oxidation and loss of zirconium.

[0007] The present invention also provides a method for preparing the above-mentioned copper-zirconium intermediate alloy cored tube, comprising the following steps:

[0008] (1) Prepare T2 copper tubes and copper-zirconium intermediate alloy for later use, with the weight ratio of the two being between 0.35 and 1;

[0009] (2) Crushing and screening: The purchased copper-zirconium master alloy is crushed and screened by a jaw crusher to separate and remove large particles with insufficient alloying, and screen out master alloy particles with a particle size ≤1.0mm; by mechanically crushing and screening the copper-zirconium master alloy to remove large particles with insufficient alloying, the impurity content can be greatly reduced, the melting point is low, and the melting speed is fast.

[0010] (3) Filling particles: The intermediate alloy particles obtained in step (2) are filled into the T2 copper tube and the air is discharged by a certain vibration to make the filling more compact;

[0011] (4) Disc stretching: The copper tube filled with copper-chromium intermediate alloy particles in step (3) is placed into a disc for multiple stretching passes to reduce the outer diameter, increase the length, and completely squeeze out the residual gas.

[0012] (5) Annealing: The copper tube drawn in step (4) is annealed under nitrogen protection to obtain a copper-zirconium master alloy core tube. Annealing under nitrogen protection can prevent oxidation and contamination by other impurities in the copper-zirconium master alloy core tube, and can also improve its stability and uniformity.

[0013] Furthermore, in step (1), the ratio of the outer diameter to the wall thickness of the copper tube is between 10 and 28.

[0014] Further, in step (4), the copper pipe after drawing has a reduction ratio of 30-80%, and a single pass reduction ratio ≤20%. In the technical solution, the copper pipe is drawn in multiple passes, so that the particles in the pipe are compacted and tightly packed, the alloy particles are prevented from leaking and separating during the subsequent wire feeding process, and the air in the pipe is further removed to reduce oxidation and burning loss; by controlling the drawing reduction ratio, the quality of the copper-chromium-zirconium alloy cored pipe is improved.

[0015] Further, in step (5), the annealing temperature is 350-550℃.

[0016] The application also provides a copper-zirconium intermediate alloy cored pipe in a non-vacuum melting and casting copper-chromium-zirconium alloy large flat ingot.

[0017] S1. Red copper smelting: using a coreless induction furnace to melt electrolytic copper plate, using charcoal to completely cover during the melting process to avoid air entering the copper liquid, and the smelting temperature is 1100-1200℃;

[0018] S2. Argon degassing: after the molten copper is heated to 1150-1200℃, it is placed for 5-15min, compressed argon is introduced into the bottom of the copper liquid through a graphite pipe for 5-15min, and the whole process is kept completely covered with charcoal;

[0019] S3. Add copper-chromium intermediate alloy: after the degassing is completed, the temperature of the copper water is increased to 1200-1250℃, the copper-chromium intermediate alloy is added according to the alloy composition ratio, and it is fully melted, the temperature is kept at 1200-1250℃, and the charcoal is completely covered;

[0020] S4. Pouring copper liquid: when the temperature of the copper water reaches 1200-1250℃, the graphite stopper is opened, the copper liquid enters the flow channel installed with an induction coil, and the flow channel induction coil heats the copper water at high power;

[0021] S5. Add copper-zirconium intermediate alloy cored pipe: during the process of filling the flow channel with copper liquid, start the wire feeder and add the copper-zirconium intermediate alloy cored pipe at a certain speed, and the speed of the wire feeder is determined according to the alloy composition ratio;

[0022] S6. Casting: when the copper liquid fills 50-85% of the volume of the flow channel, the graphite stopper of the flow channel is opened, the copper liquid enters the crystallizer, and casting is carried out, and the copper liquid in the crystallizer is completely covered with carbon black powder to obtain an ingot.

[0023] Further, in S4, the induction coil is installed at the middle section of the runner, and the heating power during production is 0-30 kW; the runner is heated by burning charcoal in advance for 30-40 min before the copper liquid flows in; the induction coil is baked by low current. By installing the induction coil at the broken section of the runner, the runner can be heated to prevent the copper liquid from flowing into the runner to cause temperature drop and affect the subsequent production.

[0024] Further, in S5, the speed of the wire feeder is controlled by PLC and is associated with the speed of the ingot casting machine; the wire feeding speed of the wire feeder is controlled according to the amount of Zr element in the ingot in unit time. The wire feeding speed is controlled by PLC to ensure that the copper-zirconium intermediate alloy pipe is continuously, uniformly and dynamically added, the oxidation and loss of zirconium are reduced, the uniformity is improved, and large-scale production is realized.

[0025] Further, in S6, the casting speed is 50-100 mm / min.

[0026] Compared with the prior art, the technical scheme of the present application has the beneficial effects that:

[0027] The copper-zirconium intermediate alloy pipe obtained by strictly controlling each process from material selection to preparation is a seamless copper pipe, which has less impurities, is dense and uniform, has no air residue, has a low melting point, and is used for non-vacuum smelting to manufacture copper-zirconium alloy, which can reduce the oxidation and loss of zirconium.

[0028] The present application optimizes the ingot production process, installs a group of induction coils horizontally at the middle section of the runner, heats the copper liquid in the runner during production to prevent the copper liquid in the runner from cooling down and affecting the addition of the copper-zirconium intermediate alloy pipe; the wire feeding speed is controlled by PLC and is associated with the speed of the ingot casting machine, the copper-zirconium intermediate alloy pipe touches the copper liquid immediately, melts and uniformly distributes in the copper liquid, and then gradually flows into the crystallizer to be cast into an ingot in a short time, which realizes continuous, uniform and dynamic addition of the copper-zirconium intermediate alloy pipe without leakage, and is used for non-vacuum smelting to manufacture copper-zirconium alloy for large-scale production. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be clearly and completely described below. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the concentration is not specified in the present application, it is the mass concentration. If the reagents or instruments are not specified by the manufacturer, they are conventional products that can be purchased in the market.

[0030] The chemical composition of the copper-chromium intermediate alloy is CuCr10.

[0031] The chemical composition of the copper-zirconium intermediate alloy is CuZr50, and the particle size is ≤1 mm.

[0032] The features and properties of the present application are further described in detail below in connection with the examples.

[0033] Example 1

[0034] A method for preparing a copper-zirconium intermediate alloy cored pipe, comprising the following steps:

[0035] (1) Prepare T2 red copper pipe and copper-zirconium intermediate alloy for standby; wherein the outer diameter of the T2 red copper pipe is 28 mm, the wall thickness is 1.0 mm, the content of zirconium in the copper-zirconium intermediate alloy is 50%, and the weight ratio of the T2 red copper pipe to the copper-zirconium intermediate alloy is 0.72;

[0036] (2) Breaking and screening: the purchased copper-zirconium intermediate alloy is broken and screened by a jaw crusher, large particles of insufficient alloying are separated and removed, and intermediate alloy particles with a particle size of ≤1.0 mm are screened out;

[0037] (3) Filling particles: the intermediate alloy particles obtained in step (2) are filled into the T2 copper pipe, and the air is discharged through a certain vibration to make the filling more compact;

[0038] (4) Disc stretching: the copper pipe filled with copper-zirconium intermediate alloy particles in step (3) is put into a disc for six-way drawing, and the pipe diameter is 28 mm-->22.95 mm-->19.17 mm-->16 mm-->13.35 mm-->11.2 mm-->9.52 mm in turn;

[0039] (5) Annealing: the copper pipe after drawing in step (4) is annealed under nitrogen protection at a temperature of 450°C to obtain a copper-zirconium intermediate alloy cored pipe, which is a seamless copper pipe with a dense cross section.

[0040] Example 2

[0041] A method for preparing a copper-zirconium intermediate alloy cored pipe, comprising the following steps:

[0042] (1) Prepare T2 red copper pipe and copper-zirconium intermediate alloy for standby; wherein the outer diameter of the T2 red copper pipe is 25 mm, the wall thickness is 1.0 mm, the content of zirconium in the copper-zirconium intermediate alloy is 50%, and the weight ratio of the T2 red copper pipe to the copper-zirconium intermediate alloy is 1;

[0043] (2) Breaking and screening: the purchased copper-zirconium intermediate alloy is broken and screened by a jaw crusher, large particles of insufficient alloying are separated and removed, and intermediate alloy particles with a particle size of ≤1.0 mm are screened out;

[0044] (3) Filling particles: the intermediate alloy particles obtained in step (2) are filled into the T2 copper pipe, and the air is discharged through a certain vibration to make the filling more compact;

[0045] (4) Disc stretching: the copper pipe filled with copper-zirconium intermediate alloy particles in step (3) is put into a disc for six-pass drawing, and the pipe diameter is 25 mm-->20.5 mm-->17.12 mm-->14.30 mm-->11.94 mm-->10.02 mm-->8.52 mm in turn;

[0046] (5) Annealing: the copper pipe drawn in step (4) is annealed under nitrogen protection at a temperature of 550°C to obtain a copper-zirconium intermediate alloy cored pipe, which is a seamless copper pipe with dense cross section.

[0047] Example 3

[0048] The application of a copper-zirconium intermediate alloy cored pipe in a non-vacuum cast copper-chromium-zirconium alloy large flat ingot, and the application method are as follows:

[0049] S1. Red copper smelting: electrolytic copper plates are melted by a coreless induction furnace, and charcoal is completely covered during the melting process to avoid air entering the copper liquid, and the smelting temperature is 1200°C;

[0050] S2. Argon degassing: after the melted copper water is heated to 1200°C, it is placed for 5 min, compressed argon is introduced into the bottom of the copper liquid through a graphite pipe for 5 min, and the whole process is kept with charcoal completely covered;

[0051] S3. Adding copper-chromium intermediate alloy: after the degassing is completed, the temperature of the copper water is increased to 1250°C, the copper-chromium intermediate alloy is added according to the alloy composition ratio, and it is fully melted, the temperature is kept at 1250°C, and the charcoal is completely covered;

[0052] S4. Pouring copper liquid: when the temperature of the copper water reaches 1250°C, the graphite stopper is opened, the copper liquid enters the flow channel in which the induction coil is installed in the middle part, and at the same time the flow channel induction coil heats the copper water at high power;

[0053] S5. Adding copper-zirconium intermediate alloy cored pipe obtained in Example 1: during the filling of the flow channel with copper liquid, the wire feeder is started, the speed is controlled by PLC, and is associated with the speed of the ingot casting machine, the feeding speed of the copper-zirconium intermediate alloy cored pipe of the wire feeder is controlled according to the amount of Zr element in the unit time production of the ingot, which is 0.15%;

[0054] S6. Casting: when the copper liquid fills 50% of the volume of the flow channel, the graphite stopper of the flow channel is opened, the copper liquid enters the crystallizer, and casting is carried out at a speed of 50 mm / min, at the same time the copper liquid in the crystallizer is completely covered with carbon black powder, and no secondary cooling by water spray is used at the outlet of the crystallizer, and an ingot is obtained.

[0055] Comparative Example 1

[0056] A preparation method of a copper-zirconium intermediate alloy cored pipe, comprising the following steps:

[0057] (1) Prepare T2 red copper pipe and copper-zirconium intermediate alloy for standby use; wherein the outer diameter of the T2 red copper pipe is 28 mm, the wall thickness is 0.6 mm, the content of zirconium in the copper-zirconium intermediate alloy is 50%, and the weight ratio of the T2 red copper pipe to the copper-zirconium intermediate alloy is 1;

[0058] (2) Breaking and screening: the purchased copper-zirconium intermediate alloy is broken and screened by a jaw crusher, large particles of insufficient alloying are separated and removed, and intermediate alloy particles with a particle size of ≤1.0 mm are screened out;

[0059] (3) Filling particles: the intermediate alloy particles obtained in step (2) are filled into the T2 copper pipe, and the air is discharged through vibration to make the filling more compact;

[0060] (4) Disc stretching: the copper pipe filled with copper-zirconium intermediate alloy particles in step (3) is placed in a disc, and six passes of drawing are planned, but frequent breakage occurs when stretching from Ø19.17 mm to Ø16 mm, and the copper pipe cannot be stretched.

[0061] Comparative Example 2

[0062] An application of a copper-zirconium intermediate alloy cored pipe in non-vacuum melting and casting of a copper-chromium-zirconium alloy large flat ingot, and the application method is as follows: the difference from Example 4 is that:

[0063] S4: Pouring copper liquid: when the temperature of the copper water reaches 1200℃, open the graphite stopper;

[0064] S5: Adding the copper-zirconium intermediate alloy cored pipe obtained in Example 1: during the filling of the copper liquid into the flow channel, the wire feeder is started, and the feeding speed of the copper-zirconium intermediate alloy cored pipe of the wire feeder is controlled according to the amount of Zr element of 0.15% in the cast ingot per unit time.

[0065] Comparative Example 3

[0066] During the casting process, a pure copper strip with a wall thickness of 0.4 mm purchased on the market is wrapped around a cored wire with a diameter of 6 mm of CuZr50 intermediate alloy powder, a wire feeder is used, and the cored wire is continuously added to the flow channel at a speed matching the casting speed, and other conditions are exactly the same as in Example 3.

[0067] Test Example

[0068] The chromium and zirconium contents in different parts of the cast ingots cast in Example 3 and Comparative Examples 2-3 are tested, and the results are shown in Table 1. The composition is measured from the beginning to the end of the cast ingot at an interval of 1 meter, wherein the maximum deviation of zirconium % = (maximum zirconium content - minimum zirconium content) x 100 / average value of zirconium content in each part.

[0069] Table 1 Zirconium content in different parts of chromium, ingot

[0070]

[0071] From the results of Table 1, it can be seen that the copper chromium zirconium alloy large flat ingot prepared by the copper zirconium intermediate alloy cored pipe prepared by the application has uniform zirconium distribution and low burning loss.

[0072] In summary, by strictly controlling each process from material selection to preparation, the copper zirconium intermediate alloy pipe obtained by filling and drawing is a seamless copper pipe, which has less impurities, is dense and uniform, has no air residue, and has low melting point; at the same time, by controlling the flow channel temperature of the non-vacuum smelting copper chromium zirconium alloy and the wire feeding speed of the copper zirconium intermediate alloy cored pipe and other processes, the oxidation and loss of zirconium can be reduced, the distribution is uniform, and the mold production is realized.

[0073] Finally, it should also be noted that the above enumeration is only a few specific embodiments of the present application. Obviously, the present application is not limited to the above embodiments, but can also have many variations. All variations that can be directly derived or inferred from the disclosed content by those of ordinary skill in the art should be considered as falling within the scope of the present application.

Claims

1. A copper-zirconium master alloy cored tube characterized by, The copper-zirconium intermediate alloy cored pipe comprises an inner core and a cladding layer, the cladding layer is a T2 copper pipe, and the inner core is copper-zirconium intermediate alloy particles with a particle size of less than or equal to 1.0 mm and without unalloyed or insufficiently alloyed elements; The preparation method of the copper-zirconium intermediate alloy cored pipe comprises the following steps: (1) preparing T2 copper pipes and copper-zirconium intermediate alloy, for standby, wherein the weight ratio of the two is 0.35-1; the ratio of the outer diameter to the wall thickness of the T2 copper pipe is between 10 and 28; (2) crushing and screening: crushing and screening the purchased copper-zirconium intermediate alloy by a jaw crusher, separating and removing large particles of insufficiently alloyed elements, and screening intermediate alloy particles with a particle size of less than or equal to 1.0 mm; (3) loading particles: loading the intermediate alloy particles obtained in step (2) into the T2 copper pipe and discharging the air in the pipe by vibration; (4) disc stretching: placing the copper pipe filled with copper-zirconium intermediate alloy particles in step (3) into a disc for multi-pass drawing; the reduced diameter rate of the drawn copper pipe is 30-80%, and the single-pass reduced diameter rate is less than or equal to 20%; (5) annealing: annealing the drawn copper pipe in step (4) under nitrogen protection to obtain a copper-zirconium intermediate alloy cored pipe.

2. A copper-zirconium master alloy cored tube according to claim 1, characterized in that The zirconium content in the copper-zirconium intermediate alloy particles is 45-55%.

3. A copper-zirconium master alloy cored tube according to claim 1, characterized in that In step (5), the annealing temperature is 350-550℃.

4. Use of a copper-zirconium master alloy cored pipe according to any one of claims 1 to 3 for the production of non-vacuum casted copper-chromium-zirconium alloy large flat ingots, characterized in that, The application method is as follows: S1. Red copper smelting: using a coreless induction furnace to melt electrolytic copper plates, using charcoal to completely cover the smelting process to avoid air entering the copper liquid, and the smelting temperature is 1100-1200℃; S2. Argon degassing: after the molten copper water is heated to 1150-1200℃, it is placed for 5-15 min, compressed argon is introduced into the bottom of the copper liquid through a graphite pipe for 5-15 min, and the whole process is kept with charcoal completely covered; S3. Adding copper-chromium intermediate alloy: after the degassing is completed, the temperature of the copper water is increased to 1200-1250℃, the copper-chromium intermediate alloy is added according to the alloy composition ratio, and it is fully melted, the temperature is kept at 1200-1250℃, and the charcoal is completely covered; S4. Pouring copper liquid: when the temperature of the copper water reaches 1200-1250℃, the graphite stopper is opened, the copper liquid enters the flow channel installed with an induction coil, and the flow channel induction coil heats the copper water at high power at the same time; S5. Adding copper-zirconium intermediate alloy cored pipe: during the filling of the copper liquid into the flow channel, the wire feeder is started, the copper-zirconium intermediate alloy cored pipe is added at a certain speed, and the speed of the wire feeder is determined according to the alloy composition ratio; S6. Casting: when the copper liquid fills 50-85% of the volume of the flow channel, the graphite stopper of the flow channel is opened, the copper liquid enters the crystallizer, and casting is carried out, at the same time, the copper liquid in the crystallizer is completely covered with carbon black powder, and the ingot is obtained.

5. Use according to claim 4, characterized in that, In S4, the induction coil is installed in the middle section of the flow channel, the heating power during production is 0-30kW; before the copper liquid flows in, the flow channel is heated and baked for 30-40 min in advance by burning charcoal; the induction coil is baked by passing a low current.

6. Use according to claim 4, characterized in that, In S5, the speed of the wire feeder is controlled by PLC and is associated with the speed of the ingot casting machine; the wire feeding speed of the wire feeder is controlled according to the amount of Zr element in the cast ingot per unit time.

7. Use according to claim 4, characterized in that, In S6, the casting speed is 50-100 mm / min.

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