Production process of high-performance copper rod for fine wire

Abstract

The invention discloses a production process of a high-performance copper rod for a fine wire, which comprises the following steps: step 1, smelting in a shaft furnace: feeding a metal copper raw material into a smelting furnace for smelting; 2, stepped casting speed increasing and dynamic cooling control are conducted, specifically, molten copper obtained through smelting in the step 1 is poured into a cast wheel mold, the casting speed is increased in a staged mode, the water amount of a cast wheel cooling area is dynamically set according to the casting speed, the temperature range of a copper casting blank before rolling is controlled to be 860-890 DEG C, and the oxygen content range of a copper rod is adjusted to be 220-290 ppm through a lower launder oxygenation pipe; and 3, rolling and take-up packaging are conducted, specifically, the copper casting blank obtained in the step 2 is continuously rolled, before rolling, the carbon coating pressure is increased to 40-45 psi, the carbon coating flow is increased by 2-3%, an obtained copper rod is subjected to acid-free cleaning, the copper rod is dried through an air pipe, and take-up packaging is conducted after waxing. By means of the process, the casting speed of the copper rod for producing the fine wires is increased to 44 tons / hour, and high stability and low defect rate of the performance of the copper rod are both considered.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of copper material calendering processing, and particularly relates to a high-performance copper rod production method based on a continuous casting and rolling process, and is particularly suitable for the preparation of high-quality low-oxygen copper rods for micro-filament manufacturing. BACKGROUND

[0002] At present, the mainstream equipment for domestic continuous casting and rolling production of copper rods is mainly SCR7000 of the United States, and the production process of copper rods involves multiple links such as vertical furnace smelting, casting machine casting, rolling mill rolling, take-up and packaging, and is closely related and inseparable, and the change of parameters greatly changes the quality of the copper rod.

[0003] However, through the collection and statistics of the data of the production process, it is found that the existing process faces the following key technical problems when producing copper rods for micro-filaments: 1. Surface quality defects: Low-speed production cannot meet the requirements of the market and the interests of the company, but when the casting speed is increased to 44 tons / hour, the casting blank is prone to cracking, and the gas holes in the casting blank also increase, thereby causing unqualified copper rods. At the same time, the diameter control of the copper rod is difficult, the surface unqualified rate increases, and the eddy current flaw increases.

[0004] 2. Inhomogeneous metallographic structure: When the cooling process parameters of the casting machine (such as the cooling water quantity of the casting wheel 3 zone and 4 zone) are unreasonable, the cooling intensity of the casting blank is uneven, which may cause problems such as excessive growth of columnar crystals and center line deviation, affecting the uniformity of the grain structure inside the copper rod, and thereby causing the copper rod to produce a scab, which is extremely prone to breakage during micro-filament processing.

[0005] 3. Large fluctuation of oxygen content: The parameter of oxygen content is extremely important in the production process. When the casting speed is increased, the flow speed of the copper liquid is accelerated, and it will be more difficult to stabilize the oxygen content at the front end. The current production process causes a large fluctuation of oxygen content, and a low oxygen content is prone to cause torsional cracks, and a high oxygen content increases the resistivity.

[0006] The above problems are caused by isolated regulation of process parameters, poor dynamic matching of cooling, and difficulty in meeting the high stability and low defect rate requirements of copper rod performance for micro-filament processing. SUMMARY

[0007] The purpose of the present application is to solve the problems of inhomogeneous metallographic structure, surface quality defects (inclusions, scabs, etc.) and difficulty in balancing production speed and quality in the production of existing copper rods for micro-filaments, and to provide a high-performance copper rod production process for micro-filaments with uniform organization, high surface quality and stable production efficiency.

[0008] To achieve the above purpose, the technical scheme adopted by the present application is: A high-performance copper rod production process for micro-filaments, comprising the following steps: Step one, vertical furnace smelting Send the copper raw material into the smelting furnace for melting; Step two, stepwise casting speed increase and dynamic cooling control Pour the molten copper from step one into the casting wheel mold, and increase the casting speed by 0.5 tons / hour in stages based on the 42 tons / hour casting speed, with stable operation for 72 hours in each stage until the final casting speed of 44 tons / hour is reached. The water quantity in the cooling area of the casting wheel is dynamically set according to the casting speed, and the specific operation method is as follows: first increase the water quantity in the three zones of the casting wheel by 10%, and increase the water quantity in the three zones of the steel belt by 2-3%, then increase the water quantity in the four zones of the casting wheel by 10%, and increase the water quantity in the four zones of the steel belt by 2-3%, and increase the water quantity in the post-cooling area of the casting machine by 20-25%, control the copper casting blank temperature before rolling in the range of 860-890℃, and at the same time, adjust the oxygen content of the copper rod through the oxygen increasing pipe of the downflow tank, and control the oxygen content in the range of 220-290 ppm.

[0009] Step three, rolling and take-up packaging The copper casting blank in step two is continuously rolled, the carbon coating pressure is increased to 40-45 psi before rolling, the carbon coating flow is increased by 2-3%, the obtained copper rod is subjected to acid-free cleaning, the copper rod is dried using an air pipe, and is packaged after being coated with wax.

[0010] Through the above process, the casting speed of the copper rod for producing micro wires is increased to 44 tons / hour, and the requirements for uniformity of the metallographic structure and low defect rate of the surface can be met.

[0011] Compared with the prior art, the present application has the following advantages: 1. Optimized metallographic structure: by controlling the cooling water quantity and cooling intensity, the rolling-in temperature is in the range of 860-890℃, the columnar crystal and equiaxed crystal are uniformly distributed, the grain size uniformity is improved by 30%, and the micro wire processing breakage rate is reduced by 40%.

[0012] 2. Improved surface quality: by adjusting the carbon coating flow and pressure, matching the rolling mill speed, the porosity on the side of the casting blank and the steel belt is greatly reduced, the surface scratch defect rate is reduced by 80%, and the requirements for micro wire processing are met.

[0013] 3. Reasonable range of oxygen content: when the casting speed is increased to 44 tons / hour, the copper water flow will be accelerated, and the effect of oxygen increasing in the downflow tank at the rear end will be more obvious compared with the oxygen increasing at the front end. The oxygen content is fine-tuned through the oxygen increasing pipe of the downflow tank at the rear end, and the oxygen content control is more stable. Low oxygen content is easy to cause torsional cracks, and high oxygen content will increase the resistivity. The oxygen content of the copper rod is stabilized in the range of 220-290 ppm, the crack defects are greatly reduced, and the resistivity will not exceed the standard.

[0014] 4. Production efficiency and stability: stable casting speed of 44 tons / hour, daily output increased by 53 tons, and annual production capacity increased by about 16%.

[0015] 5. Energy consumption reduction: natural gas consumption decreased by 0.51 m³ / t, and electricity consumption decreased by 5.12 degrees / ton.

[0016] 6. Quality grading and product adaptation: A+ grade copper rod process standard was established, A+ grade product ratio increased from 30% to 55%, meeting the needs of fine wire, enameled wire, extra-high voltage cable and other products, and product added value increased by 20%. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A copper rod metallographic structure phase diagram obtained by dynamically setting the water quantity of the casting wheel cooling area according to the stage-by-stage improvement of the casting speed in Example 1 of the present application, Figure 1 a is a copper rod cross section, Figure 1 b is a copper rod cross section; Figure 2 A copper rod metallographic structure phase diagram obtained by not dynamically controlling the water quantity of the casting wheel cooling area as the casting speed improves in Comparative Example 1 of the present application, Figure 2 a is a copper rod cross section, Figure 2 b is a copper rod cross section; Figure 3 A copper rod torsional crack diagram obtained by controlling the oxygen content of the copper rod in process step 2 to be in the range of 250 ppm in Example 2 of the present application. Figure 4 A copper rod torsional crack diagram obtained by controlling the oxygen content of the copper rod in process step 2 to be in the range of 150 ppm in Comparative Example 2 of the present application. DETAILED DESCRIPTION

[0018] The technical solutions of the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. EMBODIMENT

[0019] The present application provides a high-performance copper rod production process for fine wire, comprising the following steps: A high-performance copper rod production process for fine wire, comprising the following steps: Step 1, vertical furnace smelting The metal copper raw material is sent into the smelting furnace for melting; Step 2, step-by-step casting speed improvement and dynamic cooling control The molten copper liquid in step one is poured into a casting wheel mold, and the casting speed is increased by 0.5 tons / hour in stages, with a stable operation of 72 hours in each stage, until the final casting speed of 44 tons / hour is reached. According to the dynamic setting of the casting speed, the water quantity of the cooling area of the casting wheel is increased by 10% in the first three zones, and the water quantity of the fourth zone is increased by 10%. The water quantity of the fourth zone of the steel belt is increased by 2-3%, and the water quantity of the cooling area after the casting machine is increased by 20-25%. The temperature of the cast billet before rolling is controlled in the range of 860-890℃, and the oxygen content of the copper rod is adjusted through the oxygen enrichment pipe of the downflow tank, and the oxygen content is controlled at 250 ppm.

[0020] Step three, rolling and take-up packaging The copper cast billet in step two is continuously rolled, the carbon coating pressure is increased to 40-45 psi before rolling, and the carbon coating flow is increased by 2-3%. The obtained copper rod is subjected to acid-free cleaning, dried by air pipe, and packaged after waxing.

[0021] Comparative example 1 The present application provides a high-performance copper rod production process for microfilaments, comprising the following steps: A high-performance copper rod production process for microfilaments, comprising the following steps: Step one, smelting in a shaft furnace The metal copper raw material is sent into a smelting furnace for melting; Step two, stepwise increase of casting speed and dynamic cooling control The molten copper liquid in step one is poured into a casting wheel mold, and the casting speed is increased by 0.5 tons / hour in stages, with a stable operation of 72 hours in each stage, until the final casting speed of 44 tons / hour is reached. According to the dynamic setting of the casting speed, the water quantity of the cooling area of the casting wheel is increased by 10% in the first three zones, and the water quantity of the fourth zone is increased by 10%. The water quantity of the fourth zone of the steel belt is increased by 2-3%, and the water quantity of the cooling area after the casting machine is increased by 20-25%. The temperature of the cast billet before rolling is controlled in the range of 860-890℃, and the oxygen content of the copper rod is adjusted through the oxygen enrichment pipe of the downflow tank, and the oxygen content is controlled at 250 ppm.

[0022] Step three, rolling and take-up packaging The copper cast billet in step two is continuously rolled, the carbon coating pressure is increased to 40-45 psi before rolling, and the carbon coating flow is increased by 2-3%. The obtained copper rod is subjected to acid-free cleaning, dried by air pipe, and packaged after waxing.

[0023] Process comparison of example 1 and comparative example 1, Figure 1 The metallographic distribution is uniform, there are a small amount of equiaxed crystals on the surface, and the inside is columnar crystal; Figure 2The columnar crystal of the cast wheel is developed, the center line is deviated, and the uniformity of the metallographic structure is not conducive, which shows that the uniformity of the grain structure in the copper rod is ensured through the stepwise casting speed promotion and the dynamic cooling control, thereby avoiding the generation of scabs in the subsequent copper rod, and the fine wire is not easy to break during processing. Embodiment

[0024] The application provides a high-performance copper rod production process for fine wires, which comprises the following steps. A high-performance copper rod production process for fine wires, comprising the following steps: Step one, vertical furnace smelting The metal copper raw material is sent into a smelting furnace for melting; Step two, stepwise casting speed promotion and dynamic cooling control The copper liquid smelted in step one is poured into a cast wheel mold, and the casting speed is promoted by 0.5 tons / hour in stages based on the casting speed of 42 tons / hour, and each stage is stably operated for 72 hours until the final casting speed of 44 tons / hour is reached. The water quantity of the cooling area of the cast wheel is dynamically set according to the casting speed, and the specific operation mode is as follows: first, increase the water quantity of the three zones of the cast wheel by 10%, and increase the water quantity of the three zones of the steel belt by 2-3%; then, increase the water quantity of the four zones of the cast wheel by 10%, and increase the water quantity of the four zones of the steel belt by 2-3%; and increase the water quantity of the post-cooling area of the cast wheel by 20-25%, control the temperature range of the cast blank before rolling to be 860-890 DEG C, and adjust the oxygen content of the copper rod through the oxygen increasing pipe of the downflow tank, and the oxygen content is controlled to be 250 ppm.

[0025] Step three, rolling and take-up packaging The copper cast blank in step two is continuously rolled, the carbon coating pressure is increased to 40 psi before rolling, the carbon coating flow is increased by 2-3%, the obtained copper rod is subjected to acid-free cleaning, the copper rod is dried by using an air pipe, and the copper rod is packaged after being coated with wax.

[0026] Comparative example 2 The application provides a high-performance copper rod production process for fine wires, which comprises the following steps. A high-performance copper rod production process for fine wires, comprising the following steps: Step one, vertical furnace smelting The metal copper raw material is sent into a smelting furnace for melting; Step two, stepwise casting speed promotion and dynamic cooling control The molten copper liquid in step one is poured into the casting wheel mold, and based on the casting speed of 42 tons / hour, the casting speed is increased by 0.5 tons / hour in stages, and each stage is stably operated for 72 hours until the final casting speed of 44 tons / hour is reached. The water quantity of the cooling area of the casting wheel is dynamically set according to the casting speed, and the specific operation method is as follows: first, the water quantity of the three zones of the casting wheel is increased by 10%, the water quantity of the three zones of the steel belt is increased by 2-3%, then the water quantity of the four zones of the casting wheel is increased by 10%, the water quantity of the four zones of the steel belt is increased by 2-3%, the water quantity of the cooling area after the casting machine is increased by 20-25%, the temperature range of the cast billet before rolling is controlled to be 860-890℃, and at the same time, the oxygen content of the copper rod is adjusted through the oxygen increasing pipe of the downflow tank, and the oxygen content is controlled to be 150 ppm.

[0027] Step three, rolling and take-up packaging The copper cast billet in step two is continuously rolled, the carbon coating pressure is increased to 40 psi before rolling, and the carbon coating flow is increased by 2-3%, the obtained copper rod is subjected to acid-free cleaning, the copper rod is dried using an air pipe, and is packaged after being coated with wax.

[0028] Process comparison of example 2 and comparative example 2, as shown in the description Figure 3 , 4 comparison, although there is a step-by-step increase in casting speed and dynamic cooling control, the oxygen content range of the downflow tank copper rod is not reasonable, and low oxygen content (<220 ppm) is easy to cause torsional cracks, which proves that the above process needs to be implemented under the synergistic action of each process step.

[0029] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A high performance copper rod production process for microfilaments, characterized by, It comprises the following steps: Step one: vertical furnace smelting, sending the copper raw material into the smelting furnace for melting; Step two: stepwise casting speed increase and dynamic cooling control, pouring the copper liquid obtained in step one into the casting wheel mold, then increasing the casting speed in stages, dynamically setting the water quantity of the casting wheel cooling area according to the casting speed, controlling the temperature range of the copper casting blank before rolling to be 860-890℃, and adjusting the oxygen content of the copper rod through the oxygen-increasing pipe of the downspout; Step three: rolling and coiling and packaging, continuously rolling the copper casting blank obtained in step two, adjusting the carbon coating pressure and flow before rolling, performing acid-free cleaning on the obtained copper rod, drying the copper rod using the air pipe, and coiling and packaging after waxing.

2. A high performance copper rod production process for micro wires as claimed in claim 1, wherein, In step two, the specific operation mode of the stepwise increase of the casting speed is to increase the casting speed by 0.5 tons / hour in stages based on the casting speed of 42 tons / hour, and each stage is stably operated for 72 hours until the final casting speed of 44 tons / hour is reached.

3. A high performance copper rod production process for micro wires as claimed in claim 1, wherein, In step two, the specific operation mode of the dynamic setting of the water quantity of the casting wheel cooling area according to the casting speed is to first increase the water quantity of the three zones of the casting wheel by 10%, and the water quantity of the three zones of the steel belt by 2-3%, then increase the water quantity of the four zones of the casting wheel by 10%, and the water quantity of the four zones of the steel belt by 2-3%, and finally increase the water quantity of the cooling area after the casting machine by 20-25%.

4. A high performance copper rod production process for micro wires as claimed in claim 1, wherein, In step two, the specific operation mode of the adjustment of the oxygen content of the copper rod through the oxygen-increasing pipe of the downspout is to adjust the oxygen content of the copper rod to be in the range of 220-290 ppm.

5. A high performance copper rod production process for micro wires as claimed in claim 1, wherein, In step three, the specific operation mode of the adjustment of the carbon coating pressure before rolling is to increase the carbon coating pressure by 40-45 psi.

6. A high performance copper rod production process for micro wires as claimed in claim 1, wherein, In step three, the specific operation mode of the adjustment of the carbon coating flow before rolling is to increase the carbon coating flow by 2-3%.

7. The high-performance copper rod for microfilaments produced by the process according to any one of claims 1-6.

8. The high performance copper rod for microfilaments obtained according to claim 7, characterized by that, When the casting speed is increased to 44 tons / hour, the unqualified rate of eddy current testing is reduced to below 20%, and the microfilament processing breakage rate is reduced by 40%.

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