A method for processing red copper plate strip

Abstract

The application discloses a processing method of red copper plate strip, which comprises rough rolling, intermediate annealing, finish rolling, bottom-remaining annealing and finished product rolling. The application improves the surface quality of the red copper plate strip by controlling the roughness of the roller in each cold rolling processing stage. The application obtains a completely recrystallized structure with uniform organization by synergistically optimizing the annealing process and the pass processing rate and total processing rate of specific passes, and improves the strength and hardness of the red copper plate strip and the dimensional accuracy.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of copper material processing, and particularly relates to a processing method of red copper plate strip. BACKGROUND

[0002] Copper and copper alloy plate strip has excellent electric conductivity, thermal conductivity, corrosion resistance, electric connection and electric contact, and is widely used in various industrial fields such as machinery, electronics, automobiles, electric power, communication and transportation. Compared with traditional fuel vehicles, new energy vehicles significantly increase the use of copper; in view of improving efficiency, electrical safety and other aspects, new energy vehicles also have higher requirements for the performance of copper materials. Red copper has good electric conductivity and thermal conductivity, excellent plasticity, and is easy to be hot-pressed and cold-pressed, and is mainly used for manufacturing electric wires, cables, brushes, electric spark special etching copper and other products requiring good electric conductivity, and is the main material of copper strip for new energy vehicles.

[0003] At present, the red copper plate strip is mainly produced by using the traditional three-stage processing technology, that is, vertical continuous casting, hot rolling and cold rolling, and annealing treatment is required in the cold rolling stage. Since the red copper strip after annealing treatment is in a state between complete recrystallization and incomplete recrystallization, the uniformity of the strip structure is difficult to control, which leads to large deviation of the strength and hardness of the strip in the use process; at the same time, a series of problems such as unstable rolling size, poor size precision control and poor product surface quality may occur. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a processing method of red copper plate strip, so as to solve the problem that the red copper plate strip cannot obtain stable size precision, strength and hardness by annealing treatment or conventional rolling in the prior art.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] A processing method of red copper plate strip, comprising the following steps:

[0007] S1. Rough rolling: cold rolling of red copper hot rolling blank, total processing rate is 80-90%, first pass processing rate is less than or equal to 20%, and last pass processing rate is less than or equal to 15%, to obtain a cold rolling blank;

[0008] S2. Intermediate annealing: intermediate annealing treatment of the cold rolling blank under a protective gas atmosphere, annealing temperature is 350-450 DEG C, holding time is 5-8h, then acid and alkali washing is carried out, to obtain an intermediate annealing blank;

[0009] S3. Finish rolling: cold rolling of the intermediate annealing blank, total processing rate is 50-60%, first pass processing rate is 40-45%, and subsequent passes are rolled according to a processing rate less than or equal to 10%, to obtain a finish rolling blank;

[0010] S4. Bottom annealing: the finish rolling blank is subjected to bottom annealing treatment under a protective gas atmosphere, the annealing temperature is 550-650℃, the holding time is 40-70s, then cleaning is performed, and a bottom annealing blank is obtained;

[0011] S5. Product rolling: the bottom annealing blank is subjected to product finish rolling, the rolling deformation is 4-8%, after edge cutting, cleaning and stretch bending straightening, a finished red copper plate strip is obtained.

[0012] Preferably, in step S1, the surface roughness of the roller used is 0.5-0.6μm.

[0013] Preferably, in step S3, the surface roughness of the roller used is 0.3-0.4μm.

[0014] Preferably, in step S5, the surface roughness of the roller used is 0.1-0.2μm.

[0015] Preferably, in step S1, the rolling pass is 6-7 passes.

[0016] Preferably, in step S2, the intermediate annealing adopts a staged annealing process, the temperature is first raised to 380-400℃, the holding time is 1-2h, then the temperature is lowered to 350-365℃, the holding time is 1-1.5h, then the temperature is raised to 425-450℃, the holding time is 2-2.5h, and finally the temperature is lowered to 390-410℃, the holding time is 1-2h.

[0017] More preferably, in the staged annealing process, the temperature lowering rate is 120-160℃ / h, and the temperature raising rate is 120-160℃ / h.

[0018] Preferably, in step S3, the rolling force after the first pass is 250-300KN, and the rolling speed is controlled to be 80-100m / min.

[0019] Preferably, in step S5, the rolling force is 150-200KN, and the rolling speed is 40-70m / min.

[0020] Preferably, in steps S2 and S4, the protective gas contains 20-30vt% hydrogen and 70-80vt% nitrogen.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] The application improves the surface quality of the red copper plate strip by controlling the roughness of the rolling roller in each cold rolling process stage; and the application obtains a fully recrystallized structure with uniform structure by synergistically optimizing the annealing process and the pass reduction ratio and total reduction ratio of specific passes, and improves the strength and hardness of the red copper plate strip and the dimensional accuracy. Meanwhile, the processing method of the application is simple in operation, strong in market competitiveness, and has significant economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Figure 1 is a microstructure morphology photo of the finished red copper plate strip of Example 1.

[0024] Figure 2 Figure 2 is a microstructure morphology photo of the finished red copper plate strip of Example 2. DETAILED DESCRIPTION

[0025] The application will be further described in detail below in combination with specific examples, so that those skilled in the art can more clearly understand the application. The examples are only used to explain the application, and are not used to limit the scope of the application. In the examples of the application, all raw material components are commercially available products well known to those skilled in the art, unless otherwise specified; and the technical means used are conventional means well known to those skilled in the art, unless otherwise specified.

[0026] The processing method of the red copper plate strip provided by the example of the application comprises the following steps:

[0027] S1. Rough rolling: cold rolling of the red copper hot rolling blank, total reduction ratio is 80-90%, first pass reduction ratio is ≤20%, last pass reduction ratio is ≤15%, to obtain a cold rolling blank;

[0028] S2. Intermediate annealing: intermediate annealing treatment of the cold rolling blank under a protective gas atmosphere, annealing temperature is 350-450℃, holding time is 5-8h, then acid and alkali washing, to obtain an intermediate annealing blank;

[0029] S3. Finish rolling: cold rolling of the intermediate annealing blank, total reduction ratio is 50-60%, first pass reduction ratio is 40-45%, then pass reduction ratio is ≤10%, to obtain a finish rolling blank;

[0030] S4. Bottom annealing: bottom annealing treatment of the finish rolling blank under a protective gas atmosphere, annealing temperature is 550-650℃, holding time is 40-70s, then cleaning, to obtain a bottom annealing blank;

[0031] S5. Finished product rolling: finished product finish rolling of the bottom annealing blank, rolling deformation is 4-8%, after edge cutting, cleaning, and bending and straightening, to obtain a finished red copper plate strip.

[0032] In some preferable embodiments, the surface roughness of the rolling roller used in step S1 is 0.5-0.6 μm.

[0033] In some preferable embodiments, the surface roughness of the rolling roller used in step S3 is 0.3-0.4 μm.

[0034] In some preferable embodiments, the surface roughness of the rolling roller used in step S5 is 0.1-0.2 μm.

[0035] In some preferable embodiments, the rolling pass in step S1 is 6-7 passes.

[0036] In some preferable embodiments, the intermediate annealing in step S2 adopts a grading annealing process, in which the temperature is first raised to 380-400 °C, and kept for 1-2 h, then lowered to 350-365 °C, and kept for 1-1.5 h, then raised to 425-450 °C, and kept for 2-2.5 h, and finally lowered to 390-410 °C, and kept for 1-2 h.

[0037] In some preferable embodiments, in the grading annealing process in step S2, the cooling rate is 120-160 °C / h, and the heating rate is 120-160 °C / h.

[0038] In some preferable embodiments, in step S3, the rolling force after the first pass is 250-300 KN, and the rolling speed is controlled to be 80-100 m / min.

[0039] In some preferable embodiments, in step S5, the rolling force is 150-200 KN, and the rolling speed is 40-70 m / min.

[0040] In some preferable embodiments, in steps S2 and S4, the protective gas contains 20-30 vol% of hydrogen and 70-80 vol% of nitrogen.

[0041] Example 1

[0042] The red copper plate strip provided in this example is processed by the following method:

[0043] The red copper hot rolling blank is cold-rolled, the surface roughness of the roller is 0.5 μm, the rolling pass is 6-7 passes, the first pass processing rate is 15%, the last pass processing rate is 12%, and the total processing rate is 80%; after rolling, intermediate annealing is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen, the annealing temperature is 350°C, the holding time is 8h, and then acid and alkali washing is carried out; then, finish rolling is carried out, the surface roughness of the roller is 0.4 μm, the first pass processing rate is 40%, the rolling force is controlled to be 250 KN in the following passes, the rolling speed is 80 m / min, rolling is carried out according to the processing rate of 10%, and the total processing rate is 50%; after rolling, bottom annealing treatment is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen, the annealing temperature is 650°C, the holding time is 40s, and then cleaning is carried out; finally, product finish rolling is carried out, the surface roughness of the roller is 0.2 μm, the rolling force is controlled to be 200 KN, the rolling speed is 70 m / min, and the rolling deformation is 8%; after rolling, the finished red copper plate strip with a thickness of 1.5 mm is obtained through edge cutting, cleaning and bending and straightening, and the thickness tolerance is ±0.015 mm.

[0044] Example 2

[0045] The red copper plate strip provided in the embodiment has the following processing method:

[0046] The red copper hot rolling blank is cold-rolled, the surface roughness of the roller is 0.5 μm, the rolling pass is 6-7 passes, the first pass processing rate is 15%, the last pass processing rate is 12%, and the total processing rate is 80%; after rolling, intermediate annealing is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen, the annealing temperature is 350°C, the holding time is 8h, and then acid and alkali washing is carried out; then, finish rolling is carried out, the surface roughness of the roller is 0.4 μm, the first pass processing rate is 40%, the rolling force is controlled to be 250 KN in the following passes, the rolling speed is 80 m / min, rolling is carried out according to the processing rate of 10%, and the total processing rate is 50%; after rolling, bottom annealing treatment is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen, the annealing temperature is 650°C, the holding time is 40s, and then cleaning is carried out; finally, product finish rolling is carried out, the surface roughness of the roller is 0.2 μm, the rolling force is controlled to be 200 KN, the rolling speed is 70 m / min, and the rolling deformation is 8%; after rolling, the finished red copper plate strip with a thickness of 1.5 mm is obtained through edge cutting, cleaning and bending and straightening, and the thickness tolerance is ±0.015 mm.

[0047] Example 3

[0048] The red copper plate strip provided in the embodiment has the following processing method:

[0049] The red copper hot rolling blank is cold-rolled and opened, the surface roughness of the roller is 0.6 μm, the rolling passes are 6-7 passes, the first pass processing rate is 20%, the last pass processing rate is 15%, and the total processing rate is 90%; after rolling, intermediate annealing is performed in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen, the annealing temperature is 450°C, the holding time is 5h, and then acid and alkali washing is performed; then, finish rolling is performed, the surface roughness of the roller is 0.4 μm, the first pass processing rate is 45%, the subsequent pass controls the rolling force to be 300 KN, the rolling speed is 100 m / min, the rolling is performed according to the processing rate of 8%, and the total processing rate is 60%; after rolling, bottoming annealing treatment is performed in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen, the annealing temperature is 550°C, the holding time is 70s, and then cleaning is performed; finally, product finish rolling is performed, the surface roughness of the roller is 0.15 μm, the rolling force is controlled to be 150 KN, the rolling speed is 40 m / min, and the rolling deformation is 4%; after rolling, edge cutting, cleaning, and stretch bending straightening are performed, the finished red copper plate strip with a thickness of 0.4 mm is obtained, and the thickness tolerance is ±0.01 mm.

[0050] Example 4

[0051] The red copper plate strip provided in the embodiment has the following processing method:

[0052] The red copper hot rolling blank is cold-rolled, the surface roughness of the roller is 0.6 μm, the rolling pass is 6-7 passes, the first pass processing rate is 20%, the last pass processing rate is 15%, and the total processing rate is 90%; after rolling, the intermediate annealing is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen by volume, the temperature is first raised to 400°C, the temperature is kept for 1 hour, then the temperature is reduced to 365°C within 15 minutes, the temperature is kept for 1 hour, then the temperature is raised to 450°C within 40 minutes, the temperature is kept for 2 hours, then the temperature is reduced to 410°C within 15 minutes, the temperature is kept for 1 hour, and then the acid and alkali washing is carried out; then the finish rolling is carried out, the surface roughness of the roller is 0.4 μm, the first pass processing rate is 45%, the rolling force is controlled to be 300 KN in the following passes, the rolling speed is 100 m / min, the rolling is carried out according to the processing rate of 8%, and the total processing rate is 60%; after rolling, the bottoming annealing is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen by volume, the annealing temperature is 550°C, the holding time is 70 seconds, and then the cleaning is carried out; finally, the product finish rolling is carried out, the surface roughness of the roller is 0.15 μm, the rolling force is controlled to be 150 KN, the rolling speed is 40 m / min, and the rolling deformation is 4%; after rolling, the finished red copper plate strip with a thickness of 0.4 mm is obtained through edge cutting, cleaning and bending and straightening, and the thickness tolerance is ±0.005 mm.

[0053] Example 5

[0054] The red copper plate strip provided in the embodiment has the following processing method:

[0055] The red copper hot rolling blank is cold-rolled, the surface roughness of the roller is 0.6 μm, the rolling pass is 6-7 passes, the first pass processing rate is 20%, the last pass processing rate is 15%, and the total processing rate is 90%; after rolling, the intermediate annealing is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen by volume, the temperature is first raised to 400°C, the temperature is kept for 1 hour, then the temperature is reduced to 365°C within 15 minutes, the temperature is kept for 1 hour, then the temperature is raised to 450°C within 40 minutes, the temperature is kept for 2 hours, then the temperature is reduced to 410°C within 15 minutes, the temperature is kept for 1 hour, and then the acid and alkali washing is carried out; then the finish rolling is carried out, the surface roughness of the roller is 0.4 μm, the first pass processing rate is 45%, the rolling force is controlled to be 300 KN in the following passes, the rolling speed is 100 m / min, the rolling is carried out according to the processing rate of 8%, and the total processing rate is 60%; after rolling, the bottoming annealing is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen by volume, the annealing temperature is 550°C, the holding time is 70 seconds, and then the cleaning is carried out; finally, the product finish rolling is carried out, the surface roughness of the roller is 0.15 μm, the rolling force is controlled to be 150 KN, the rolling speed is 40 m / min, and the rolling deformation is 4%; after rolling, the finished red copper plate strip with a thickness of 0.4 mm is obtained through edge cutting, cleaning and bending and straightening, and the thickness tolerance is ±0.005 mm.

[0056] Example 6

[0057] The red copper plate strip provided in the embodiment has the following processing method:

[0058] The red copper hot rolling blank is cold-rolled and opened, the surface roughness of the roller is 0.6 μm, the rolling passes are 6-7 passes, the first pass processing rate is 18%, the last pass processing rate is 15%, and the total processing rate is 85%; after rolling, the intermediate annealing is performed in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen by using a grading annealing process, the temperature is first raised to 390°C, and then kept for 1 h, then reduced to 360°C within 15 min, kept for 1.5 h, then raised to 430°C within 30 min, kept for 2 h, then reduced to 400°C within 15 min, kept for 1.5 h, and then acid and alkali washing is performed; then, the finish rolling is performed, the surface roughness of the roller is 0.3 μm, the first pass processing rate is 43%, the rolling force is controlled to be 280 KN, the rolling speed is 90 m / min, the rolling is performed according to the processing rate of 7%, and the total processing rate is 55%; after rolling, the bottom remaining annealing treatment is performed in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen, the annealing temperature is 600°C, and the keeping time is 60 s, and then cleaning is performed; finally, the finished product finish rolling is performed, the surface roughness of the roller is 0.2 μm, the rolling force is controlled to be 180 KN, the rolling speed is 60 m / min, and the rolling deformation is 6%; after rolling, the finished product red copper plate strip with a thickness of 0.8 mm is obtained through edge cutting, cleaning and bending and straightening, and the thickness tolerance is ±0.004 mm.

[0059] Example 7

[0060] The red copper plate strip provided in the embodiment has the following processing method:

[0061] The red copper hot rolling blank is cold-rolled, the surface roughness of the roller is 0.55 μm, the rolling pass is 6-7 passes, the first pass processing rate is 20%, the last pass processing rate is 15%, and the total processing rate is 88%; after rolling, intermediate annealing is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen, the annealing temperature is 420°C, the holding time is 7h, then acid and alkali washing is carried out; then, finish rolling is carried out, the surface roughness of the roller is 0.3 μm, the first pass processing rate is 44%, the rolling force is controlled to be 290 KN, the rolling speed is 950 m / min, rolling is carried out according to the processing rate of 8%, and the total processing rate is 60%; after rolling, bottom annealing treatment is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen, the annealing temperature is 580°C, the holding time is 70s, then cleaning is carried out; finally, product finish rolling is carried out, the surface roughness of the roller is 0.15 μm, the rolling force is controlled to be 190 KN, the rolling speed is 65 m / min, and the rolling deformation is 7%; after rolling, the finished red copper plate strip with a thickness of 0.7 mm is obtained through edge cutting, cleaning and bending and straightening, and the thickness tolerance is ±0.01 mm.

[0062] Example 8

[0063] The red copper plate strip provided in the embodiment has the following processing method:

[0064] The red copper hot rolling blank is cold-rolled, the surface roughness of the roller is 0.55 μm, the rolling pass is 6-7 passes, the first pass processing rate is 20%, the last pass processing rate is 15%, and the total processing rate is 88%; after rolling, intermediate annealing is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen, the annealing temperature is 420°C, the holding time is 7h, then acid and alkali washing is carried out; then, finish rolling is carried out, the surface roughness of the roller is 0.3 μm, the first pass processing rate is 44%, the rolling force is controlled to be 290 KN, the rolling speed is 950 m / min, rolling is carried out according to the processing rate of 8%, and the total processing rate is 60%; after rolling, bottom annealing treatment is carried out in a protective gas atmosphere containing 25% hydrogen and 75% nitrogen, the annealing temperature is 580°C, the holding time is 70s, then cleaning is carried out; finally, product finish rolling is carried out, the surface roughness of the roller is 0.15 μm, the rolling force is controlled to be 190 KN, the rolling speed is 65 m / min, and the rolling deformation is 7%; after rolling, the finished red copper plate strip with a thickness of 0.7 mm is obtained through edge cutting, cleaning and bending and straightening, and the thickness tolerance is ±0.01 mm.

[0065] The samples taken from 10 different positions of the finished red copper plate strip of Examples 1-8 were tested, and the results are shown in Table 1.

[0066] Table 1

[0067]

[0068] Figure 1 The microstructure photograph of the finished red copper plate strip of Example 1 shows that the grain size is uniform and less than 20 μm. Figure 2 The microstructure photograph of the finished red copper plate strip of Example 2 shows that the grain size is more uniform and less than 10 μm.

[0069] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for processing copper sheet and strip, characterized in that, Includes the following steps: S1. Rough rolling: Cold rolling is performed on the hot-rolled copper billet to obtain a cold-rolled billet with a total processing rate of 80-90%, a first pass processing rate of ≤20%, and a last pass processing rate of ≤15%. S2. Intermediate annealing: The cold-rolled billet is subjected to intermediate annealing in a protective gas atmosphere at an annealing temperature of 350~450℃ and a holding time of 5~8h. Then, it is subjected to acid and alkali washing to obtain the intermediate annealed billet. S3. Finish rolling: The intermediate annealed billet is cold rolled with a total processing rate of 50-60%, the first pass processing rate is 40-45%, and subsequent passes are rolled with a processing rate of ≤10% to obtain a finish rolled billet; S4. Under-heat annealing: The finished rolled billet is subjected to under-heat annealing treatment in a protective gas atmosphere at an annealing temperature of 550~650℃ and a holding time of 40~70s. Then it is cleaned to obtain the under-heat annealed billet. S5. Finished product rolling: The annealed billet with the bottom remaining is finished product precision rolled with a rolling deformation of 4~8%. After edge trimming, cleaning, and bending straightening, the finished copper strip is obtained.

2. The processing method for copper sheet and strip according to claim 1, characterized in that, In step S1, the surface roughness of the rolls used is 0.5 to 0.6 μm.

3. The processing method for copper sheet and strip according to claim 1, characterized in that, In step S3, the surface roughness of the rolls used is 0.3 to 0.4 μm.

4. The processing method of copper sheet and strip according to claim 1, characterized in that, In step S5, the surface roughness of the rolls used is 0.1 to 0.2 μm.

5. The processing method for copper sheet and strip according to claim 1, characterized in that, In step S1, the rolling passes are 6 to 7.

6. The processing method for copper sheet and strip according to claim 1, characterized in that, In step S2, the intermediate annealing adopts a staged annealing process, first raising the temperature to 380~400℃ and holding it for 1~2 hours, then lowering it to 350~365℃ and holding it for 1~1.5 hours, then raising it to 425~450℃ and holding it for 2~2.5 hours, and finally lowering it to 390~410℃ and holding it for 1~2 hours.

7. The processing method for copper sheet and strip according to claim 6, characterized in that, In the graded annealing process, the cooling rate is 120~160℃ / h and the heating rate is 120~160℃ / h.

8. The processing method for copper sheet and strip according to claim 1, characterized in that, In step S3, the rolling force for subsequent passes is 250~300KN, and the rolling speed is controlled at 80~100m / min.

9. The processing method for copper sheet and strip according to claim 1, characterized in that, In step S5, the rolling force is 150-200 kN and the rolling speed is 40-70 m / min.

10. The processing method of copper sheet and strip according to claim 1, characterized in that, In steps S2 and S4, the protective gas contains 20-30% hydrogen and 70-80% nitrogen by volume.

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