Continuous casting-continuous extrusion short-process forming process for large-width copper plate strip

Abstract

The invention relates to a continuous casting-continuous extrusion short-process forming process for a large-width copper plate strip, and belongs to the technical field of metal processing. The method comprises the following steps: preheating and drying high-purity cathode copper, melting in a smelting device, covering the surface of molten copper with charcoal and graphite flakes, carrying out on-line degassing, deoxidizing and stirring, upwards leading a copper rod by adopting a traction unit, and extruding between an extrusion wheel and a compaction wheel; a four-high rolling mill is used for rolling; cleaning and passivating the annealed copper plate strip, spraying a lanthanum (III)-containing silane-benzimidazole lubricant solution on the surface of the copper plate strip, and drying; slitting to obtain a large-width copper plate strip; the lanthanum (III)-silane-benzimidazole lubricant is prepared from vinyltriethoxysilane, deionized water, ethanol, benzimidazole and lanthanum nitrate hexahydrate (III), and the lanthanum (III)-silane-benzimidazole lubricant is prepared from the vinyltriethoxysilane, the deionized water, the ethanol, the benzimidazole and the lanthanum nitrate hexahydrate (III); the prepared copper plate strip is high in purity, low in oxygen content, high in conductivity and excellent in mechanical property, and the technical requirements of the high-end field for the high-purity high-conductivity oxygen-free copper plate strip are met.

Description

Technical Field

[0001] This invention relates to the field of metal processing technology, and in particular to a short-process forming process for continuous casting and extrusion of wide copper strip. Background Technology

[0002] Copper sheet and strip is a general term for copper plates and strips. Due to their special electrical conductivity, thermal conductivity, and corrosion resistance, they are widely used in the manufacture of various parts. Continuous extrusion technology is one of the important processing methods in copper sheet and strip processing. Continuous extrusion refers to the process where the material being extruded, after pretreatment, is forced through a specially designed die by mechanical extrusion to form an extruded product of a specific shape.

[0003] Chinese Patent CN119456669A relates to the field of copper strip processing technology, providing an advanced continuous rolling process for copper strip, including: S1. Selecting copper ingots with a copper content of 99.9% or higher, and obtaining raw materials through sawing and surface grinding; S2. Heating the processed copper ingots in a heating furnace to ensure uniform internal temperature; S3. Rolling the heated copper ingots using a roughing mill through 2-3 passes; S4. The rough-rolled copper strip enters an intermediate mill, with 3-5 passes; S5. The intermediate-rolled copper strip enters a finishing mill, with 3-4 passes; S6. Online cooling: The finishing-rolled copper strip immediately enters an online cooling system.

[0004] Chinese Patent CN108405650B: A processing technology for copper strip for moxibustion boxes, which is prepared by the following steps: S1, preparing raw material A and raw material B respectively; S2, smelting; S3, adding raw material B and smelting at a constant temperature; S4, adding a refining agent and smelting at a constant temperature; S5, adding a lubricant and casting; S6, removing oxide scale and inclusions from the surface of the cast product; S7, hot rolling to obtain a copper strip with a thickness of 4.0 mm; S8, rough rolling the 4.0 mm thick copper strip to obtain a copper strip with a thickness of 1.9 mm; S9, finish rolling the 1.9 mm thick copper strip to obtain the finished copper strip.

[0005] The existing copper strip production process has many problems. For example, the process for producing copper busbars is continuous casting-continuous extrusion-rolling-annealing-drawing-inspection-packaging. This process requires rolling and annealing after continuous extrusion before drawing, which is not only inefficient, but also results in unstable product size control, uneven mechanical properties, and large hardness deviations on the cross-section, failing to meet the requirements for use. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a short-process forming technology for continuous casting and extrusion of wide copper strips, the operation steps of which are as follows:

[0007] S1 upward continuous casting: After preheating and drying the high-purity cathode copper, it is melted in the smelting device. Charcoal and graphite flakes are used to cover the surface of the copper liquid, and it is degassed, deoxidized and stirred online. Then, the copper rod is drawn upward by the traction unit.

[0008] S2 Continuous Extrusion: The copper rod obtained from the upward continuous casting is used as the extrusion material and is continuously extruded 3 times between the extrusion wheel and the compaction wheel;

[0009] S3 rolling: Using a four-roll mill, the copper strip billet is rolled in 5 passes with pass rates of 46%, 48%, 47%, 49%, and 48%, respectively, ultimately rolling the copper strip to a thickness of 0.3 mm.

[0010] S4 Annealing: The rolled copper strip is annealed in a gas-protected bright annealing furnace at a temperature of 300-350℃ for 3-5 hours.

[0011] S5 post-treatment: The annealed copper strip is first cleaned and passivated, then 1-5 parts by weight of a lanthanum(III)-silane-benzimidazole lubricant solution containing 5-10 wt% are sprayed onto the surface of 70-100 parts by weight of the copper strip, and dried; then cut to obtain a wide copper strip.

[0012] As a preferred embodiment of the present invention, the S1 smelting apparatus includes a smelting furnace and a holding furnace; the temperature of the smelting furnace is 1150-1155℃, and it is covered with dried charcoal with a covering thickness of 120-150mm; the temperature of the holding furnace is 1145-1150℃, and it is covered with graphite flakes with a covering thickness of 30-35mm.

[0013] As a preferred embodiment of the present invention, in the three consecutive extrusions of S2, the first continuous extrusion speed is 6-7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 0.95 mm, the extrusion temperature is 710-720℃, and the pressure is 1100-1200 MPa.

[0014] As a preferred embodiment of the present invention, in the second continuous extrusion of the three extrusions in S2, the rotation speed is 6-7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.05 mm, the extrusion temperature is 720-730℃, and the pressure is 1000-1100 MPa.

[0015] As a preferred embodiment of the present invention, in the three consecutive extrusions of S2, the rotation speed of the third consecutive extrusion is 6-7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.15 mm, the extrusion temperature is 700-710℃, and the pressure is 950-1050 MPa.

[0016] As a preferred embodiment of the present invention, the preparation method of the lanthanum(III)-silane-benzimidazole lubricant is as follows:

[0017] According to the mass fraction, 15-20 parts of vinyltriethoxysilane were added to a mixture of 200-300 parts of deionized water and 250-350 parts of ethanol containing 0.1-0.4 parts of 37wt% hydrochloric acid, and the mixture was subjected to a hydrolysis-condensation reaction at 60-70℃ for 2-3 hours. Then, 6-10 parts of benzimidazole were added, and the temperature was raised to 70-80℃ for 1-3 hours. After the reaction was completed, the system was cooled to 40-50℃, and 0.02-0.07 parts of lanthanum(III) nitrate hexahydrate were added. The reaction was continued for 2-3 hours, and water and ethanol were removed by distillation to obtain lanthanum(III)-silane-benzimidazole lubricant.

[0018] Reaction mechanism:

[0019] Vinyltriethoxysilane undergoes a hydrolytic condensation reaction under acidic conditions to form siloxane oligomers; benzimidazole is chemically grafted onto the siloxane oligomers, La... 3+ It coordinates with relevant functional groups, enhancing the stability and load-bearing capacity of the lubricating film.

[0020] Technical effects:

[0021] The present invention provides a short-process forming technology for continuous casting and extrusion of wide copper strip. Compared with the prior art, the present invention has the following significant advantages:

[0022] 1. After using the lanthanum(III)-silane-benzimidazole lubricant prepared by the present invention, the coefficient of friction during the rolling process of wide copper strip is reduced; the surface quality and dimensional accuracy of the copper strip are significantly improved, while the electrical conductivity and mechanical properties are also maintained.

[0023] 2. The copper strip prepared by this invention has high purity, low oxygen content, high conductivity, and excellent mechanical properties, meeting the technical requirements of high-end fields for high-purity, high-conductivity, oxygen-free copper strips. Detailed Implementation

[0024] To further illustrate the technical means and effects adopted by the present invention in order to achieve the intended purpose, the following detailed description is provided in conjunction with embodiments and comparative examples:

[0025] 1. Copper content detection: The detection is performed using a spectroscopic analysis method with an inductively coupled plasma optical emission spectrometer (ICP-OES).

[0026] 2. Oxygen content detection: The oxygen content is detected using a pulse heating inert gas melting-infrared absorption method and an oxygen and nitrogen analyzer.

[0027] 3. Conductivity test: The conductivity is tested using a digital conductivity meter based on the bridge method.

[0028] 4. Tensile strength: The tensile test method is adopted and the test is carried out using an electronic universal testing machine.

[0029] Example 1

[0030] A short-process forming technology for continuous casting and extrusion of wide copper strips, the operation steps of which are as follows:

[0031] S1 upward continuous casting: After preheating and drying the high-purity cathode copper, it is melted in the smelting device. Charcoal and graphite flakes are used to cover the surface of the copper liquid, and it is degassed, deoxidized and stirred online. Then, the copper rod is drawn upward by the traction unit.

[0032] S2 Continuous Extrusion: The copper rod obtained from the upward continuous casting is used as the extrusion material and is continuously extruded 3 times between the extrusion wheel and the compaction wheel;

[0033] S3 rolling: Using a four-roll mill, the copper strip billet is rolled in 5 passes with pass rates of 46%, 48%, 47%, 49%, and 48%, respectively, ultimately rolling the copper strip to a thickness of 0.3 mm.

[0034] S4 Annealing: The rolled copper strip is annealed in a gas-protected bright annealing furnace at a temperature of 300°C for 3 hours.

[0035] S5 post-treatment: The annealed copper strip is first cleaned and passivated, then sprayed with 1 kg of lanthanum(III)-silane-benzimidazole lubricant solution containing 5 wt% on the surface of 70 kg of copper strip, and dried; then cut to obtain a wide copper strip.

[0036] The S1 smelting apparatus includes a smelting furnace and a holding furnace; the temperature of the smelting furnace is 1150℃, and it is covered with dried charcoal with a covering thickness of 120mm; the temperature of the holding furnace is 1145℃, and it is covered with graphite flakes with a covering thickness of 30mm.

[0037] The first continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 0.95 mm, the extrusion temperature is 710℃, and the pressure is 1100 MPa.

[0038] The second continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.05 mm, the extrusion temperature is 720℃, and the pressure is 1000 MPa.

[0039] The third continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.15 mm, the extrusion temperature is 700℃, and the pressure is 950 MPa.

[0040] The preparation method of the lanthanum(III)-silane-benzimidazole lubricant is as follows:

[0041] 15 kg of vinyltriethoxysilane was added to a mixture of 200 kg of deionized water and 250 kg of ethanol containing 0.1 kg of 37 wt% hydrochloric acid, and the mixture was subjected to a hydrolysis-condensation reaction at 60 °C for 2 h. Then, 6 kg of benzimidazole was added, and the temperature was raised to 70 °C for 1 h. After the reaction was completed, the system was cooled to 40 °C, 0.02 kg of lanthanum(III) nitrate hexahydrate was added, and the reaction was continued for 2 h. Water and ethanol were removed by distillation to obtain lanthanum(III)-silane-benzimidazole lubricant.

[0042] Example 2

[0043] A short-process forming technology for continuous casting and extrusion of wide copper strips, the operation steps of which are as follows:

[0044] S1 upward continuous casting: After preheating and drying the high-purity cathode copper, it is melted in the smelting device. Charcoal and graphite flakes are used to cover the surface of the copper liquid, and it is degassed, deoxidized and stirred online. Then, the copper rod is drawn upward by the traction unit.

[0045] S2 Continuous Extrusion: The copper rod obtained from the upward continuous casting is used as the extrusion material and is continuously extruded 3 times between the extrusion wheel and the compaction wheel;

[0046] S3 rolling: Using a four-roll mill, the copper strip billet is rolled in 5 passes with pass rates of 46%, 48%, 47%, 49%, and 48%, respectively, ultimately rolling the copper strip to a thickness of 0.3 mm.

[0047] S4 Annealing: The rolled copper strip is annealed in a gas-protected bright annealing furnace at a temperature of 310°C for 4 hours.

[0048] S5 post-treatment: The annealed copper strip is first cleaned and passivated, then sprayed with 2kg of lanthanum(III)-silane-benzimidazole lubricant solution containing 6wt% on the surface of 80kg copper strip, and dried; then cut to obtain a wide copper strip.

[0049] The S1 smelting apparatus includes a smelting furnace and a holding furnace; the temperature of the smelting furnace is 1150℃, and it is covered with dried charcoal with a covering thickness of 130mm; the temperature of the holding furnace is 1145℃, and it is covered with graphite flakes with a covering thickness of 30mm.

[0050] The first continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 0.95 mm, the extrusion temperature is 715℃, and the pressure is 1150 MPa.

[0051] The second continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.05 mm, the extrusion temperature is 725℃, and the pressure is 1050 MPa.

[0052] The third continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.15 mm, the extrusion temperature is 705℃, and the pressure is 980 MPa.

[0053] The preparation method of the lanthanum(III)-silane-benzimidazole lubricant is as follows:

[0054] 16 kg of vinyltriethoxysilane was added to a mixture of 240 kg of deionized water and 280 kg of ethanol containing 0.2 kg of 37 wt% hydrochloric acid, and the mixture was subjected to a hydrolysis-condensation reaction at 65 °C for 2.5 h. Then, 7 kg of benzimidazole was added, and the mixture was heated to 75 °C and reacted for 2 h. After the reaction was completed, the system was cooled to 45 °C, and 0.03 kg of lanthanum(III) nitrate hexahydrate was added. The reaction was continued for 2.5 h, and water and ethanol were removed by distillation to obtain lanthanum(III)-silane-benzimidazole lubricant.

[0055] Example 3

[0056] A short-process forming technology for continuous casting and extrusion of wide copper strips, the operation steps of which are as follows:

[0057] S1 upward continuous casting: After preheating and drying the high-purity cathode copper, it is melted in the smelting device. Charcoal and graphite flakes are used to cover the surface of the copper liquid, and it is degassed, deoxidized and stirred online. Then, the copper rod is drawn upward by the traction unit.

[0058] S2 Continuous Extrusion: The copper rod obtained from the upward continuous casting is used as the extrusion material and is continuously extruded 3 times between the extrusion wheel and the compaction wheel;

[0059] S3 rolling: Using a four-roll mill, the copper strip billet is rolled in 5 passes with pass rates of 46%, 48%, 47%, 49%, and 48%, respectively, ultimately rolling the copper strip to a thickness of 0.3 mm.

[0060] S4 Annealing: The rolled copper strip is annealed in a gas-protected bright annealing furnace at a temperature of 340°C for 4 hours.

[0061] S5 post-treatment: The annealed copper strip is first cleaned and passivated, then 4 kg of lanthanum(III)-silane-benzimidazole lubricant solution containing 8 wt% is sprayed onto the surface of 90 kg of copper strip and dried; then it is slit to obtain a wide copper strip.

[0062] The S1 smelting apparatus includes a smelting furnace and a holding furnace; the temperature of the smelting furnace is 1155℃, and it is covered with dried charcoal with a covering thickness of 140mm; the temperature of the holding furnace is 1150℃, and it is covered with graphite flakes with a covering thickness of 35mm.

[0063] The first continuous extrusion speed of S2 is 7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 0.95 mm, the extrusion temperature is 715℃, and the pressure is 1150 MPa.

[0064] The second continuous extrusion speed of S2 is 7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.05 mm, the extrusion temperature is 725℃, and the pressure is 1050 MPa.

[0065] The third continuous extrusion speed of S2 is 7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.15 mm, the extrusion temperature is 705℃, and the pressure is 1030 MPa.

[0066] The preparation method of the lanthanum(III)-silane-benzimidazole lubricant is as follows:

[0067] 18 kg of vinyltriethoxysilane was added to a mixture of 280 kg of deionized water and 330 kg of ethanol containing 0.3 kg of 37 wt% hydrochloric acid, and the mixture was subjected to a hydrolysis-condensation reaction at 65 °C for 2.5 h. Then, 9 kg of benzimidazole was added, and the mixture was heated to 75 °C and reacted for 2 h. After the reaction was completed, the system was cooled to 45 °C, and 0.06 kg of lanthanum(III) nitrate hexahydrate was added. The reaction was continued for 2.5 h, and water and ethanol were removed by distillation to obtain lanthanum(III)-silane-benzimidazole lubricant.

[0068] Example 4

[0069] A short-process forming technology for continuous casting and extrusion of wide copper strips, the operation steps of which are as follows:

[0070] S1 upward continuous casting: After preheating and drying the high-purity cathode copper, it is melted in the smelting device. Charcoal and graphite flakes are used to cover the surface of the copper liquid, and it is degassed, deoxidized and stirred online. Then, the copper rod is drawn upward by the traction unit.

[0071] S2 Continuous Extrusion: The copper rod obtained from the upward continuous casting is used as the extrusion material and is continuously extruded 3 times between the extrusion wheel and the compaction wheel;

[0072] S3 rolling: Using a four-roll mill, the copper strip billet is rolled in 5 passes with pass rates of 46%, 48%, 47%, 49%, and 48%, respectively, ultimately rolling the copper strip to a thickness of 0.3 mm.

[0073] S4 Annealing: The rolled copper strip is annealed in a gas-protected bright annealing furnace at a temperature of 350°C for 5 hours.

[0074] S5 post-treatment: The annealed copper strip is first cleaned and passivated, then 5 kg of a 10 wt% lanthanum(III)-silane-benzimidazole lubricant solution is sprayed onto the surface of 100 kg of copper strip and dried; then it is slit to obtain a wide copper strip.

[0075] The S1 smelting apparatus includes a smelting furnace and a holding furnace; the temperature of the smelting furnace is 1155℃, and it is covered with dried charcoal with a covering thickness of 150mm; the temperature of the holding furnace is 1150℃, and it is covered with graphite flakes with a covering thickness of 35mm.

[0076] The first continuous extrusion speed of S2 is 7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 0.95 mm, the extrusion temperature is 720℃, and the pressure is 1200 MPa.

[0077] The second continuous extrusion speed of S2 is 7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.05 mm, the extrusion temperature is 730℃, and the pressure is 1100 MPa.

[0078] The third continuous extrusion speed of S2 is 7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.15 mm, the extrusion temperature is 710℃, and the pressure is 1050 MPa.

[0079] The preparation method of the lanthanum(III)-silane-benzimidazole lubricant is as follows:

[0080] 20 kg of vinyltriethoxysilane was added to a mixture of 300 kg of deionized water and 350 kg of ethanol containing 0.4 kg of 37 wt% hydrochloric acid, and the mixture was subjected to a hydrolysis-condensation reaction at 70 °C for 3 h. Then, 10 kg of benzimidazole was added, and the mixture was heated to 80 °C and reacted for 3 h. After the reaction was completed, the system was cooled to 50 °C, and 0.07 kg of lanthanum(III) nitrate hexahydrate was added. The reaction was continued for 3 h, and water and ethanol were removed by distillation to obtain lanthanum(III)-silane-benzimidazole lubricant.

[0081] Comparative Example 1

[0082] A short-process forming technology for continuous casting and extrusion of wide copper strips, the operation steps of which are as follows:

[0083] S1 upward continuous casting: After preheating and drying the high-purity cathode copper, it is melted in the smelting device. Charcoal and graphite flakes are used to cover the surface of the copper liquid, and it is degassed, deoxidized and stirred online. Then, the copper rod is drawn upward by the traction unit.

[0084] S2 Continuous Extrusion: The copper rod obtained from the upward continuous casting is used as the extrusion material and is continuously extruded 3 times between the extrusion wheel and the compaction wheel;

[0085] S3 rolling: Using a four-roll mill, the copper strip billet is rolled in 5 passes with pass rates of 46%, 48%, 47%, 49%, and 48%, respectively, ultimately rolling the copper strip to a thickness of 0.3 mm.

[0086] S4 Annealing: The rolled copper strip is annealed in a gas-protected bright annealing furnace at a temperature of 300°C for 3 hours.

[0087] S5 Post-processing: The annealed copper strip is cleaned, passivated, and slit to obtain a wide copper strip.

[0088] The S1 smelting apparatus includes a smelting furnace and a holding furnace; the temperature of the smelting furnace is 1150℃, and it is covered with dried charcoal with a covering thickness of 120mm; the temperature of the holding furnace is 1145℃, and it is covered with graphite flakes with a covering thickness of 30mm.

[0089] The first continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 0.95 mm, the extrusion temperature is 710℃, and the pressure is 1100 MPa.

[0090] The second continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.05 mm, the extrusion temperature is 720℃, and the pressure is 1000 MPa.

[0091] The third continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.15 mm, the extrusion temperature is 700℃, and the pressure is 950 MPa.

[0092] Comparative Example 2

[0093] A short-process forming technology for continuous casting and extrusion of wide copper strips, the operation steps of which are as follows:

[0094] S1 upward continuous casting: After preheating and drying the high-purity cathode copper, it is melted in the smelting device. Charcoal and graphite flakes are used to cover the surface of the copper liquid, and it is degassed, deoxidized and stirred online. Then, the copper rod is drawn upward by the traction unit.

[0095] S2 Continuous Extrusion: The copper rod obtained from the upward continuous casting is used as the extrusion material and is continuously extruded 3 times between the extrusion wheel and the compaction wheel;

[0096] S3 rolling: Using a four-roll mill, the copper strip billet is rolled in 5 passes with pass rates of 46%, 48%, 47%, 49%, and 48%, respectively, ultimately rolling the copper strip to a thickness of 0.3 mm.

[0097] S4 Annealing: The rolled copper strip is annealed in a gas-protected bright annealing furnace at a temperature of 300°C for 3 hours.

[0098] S5 post-treatment: The annealed copper strip is first cleaned and passivated, then 1 kg of a 5 wt% lubricant solution is sprayed onto the surface of 70 kg of copper strip and dried; then it is slit to obtain a wide copper strip.

[0099] The S1 smelting apparatus includes a smelting furnace and a holding furnace; the temperature of the smelting furnace is 1150℃, and it is covered with dried charcoal with a covering thickness of 120mm; the temperature of the holding furnace is 1145℃, and it is covered with graphite flakes with a covering thickness of 30mm.

[0100] The first continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 0.95 mm, the extrusion temperature is 710℃, and the pressure is 1100 MPa.

[0101] The second continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.05 mm, the extrusion temperature is 720℃, and the pressure is 1000 MPa.

[0102] The third continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.15 mm, the extrusion temperature is 700℃, and the pressure is 950 MPa.

[0103] The method for preparing the lubricant is as follows:

[0104] 15 kg of vinyltriethoxysilane was added to a mixture of 200 kg of deionized water and 250 kg of ethanol containing 0.1 kg of 37 wt% hydrochloric acid, and the mixture was subjected to a hydrolysis-condensation reaction at 60 °C for 2 h. After the reaction was completed, the system was cooled to 40 °C, 0.02 kg of lanthanum(III) nitrate hexahydrate was added, and the reaction was continued for 2 h. Water and ethanol were removed by distillation to obtain a lubricant.

[0105] Comparative Example 3

[0106] A short-process forming technology for continuous casting and extrusion of wide copper strips, the operation steps of which are as follows:

[0107] S1 upward continuous casting: After preheating and drying the high-purity cathode copper, it is melted in the smelting device. Charcoal and graphite flakes are used to cover the surface of the copper liquid, and it is degassed, deoxidized and stirred online. Then, the copper rod is drawn upward by the traction unit.

[0108] S2 Continuous Extrusion: The copper rod obtained from the upward continuous casting is used as the extrusion material and is continuously extruded 3 times between the extrusion wheel and the compaction wheel;

[0109] S3 rolling: Using a four-roll mill, the copper strip billet is rolled in 5 passes with pass rates of 46%, 48%, 47%, 49%, and 48%, respectively, ultimately rolling the copper strip to a thickness of 0.3 mm.

[0110] S4 Annealing: The rolled copper strip is annealed in a gas-protected bright annealing furnace at a temperature of 300°C for 3 hours.

[0111] S5 post-treatment: The annealed copper strip is first cleaned and passivated, then 1 kg of a 5 wt% lubricant solution is sprayed onto the surface of 70 kg of copper strip and dried; then it is slit to obtain a wide copper strip.

[0112] The S1 smelting apparatus includes a smelting furnace and a holding furnace; the temperature of the smelting furnace is 1150℃, and it is covered with dried charcoal with a covering thickness of 120mm; the temperature of the holding furnace is 1145℃, and it is covered with graphite flakes with a covering thickness of 30mm.

[0113] The first continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 0.95 mm, the extrusion temperature is 710℃, and the pressure is 1100 MPa.

[0114] The second continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.05 mm, the extrusion temperature is 720℃, and the pressure is 1000 MPa.

[0115] The third continuous extrusion speed of S2 is 6 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.15 mm, the extrusion temperature is 700℃, and the pressure is 950 MPa.

[0116] The method for preparing the lubricant is as follows:

[0117] 15 kg of vinyltriethoxysilane was added to a mixture of 200 kg of deionized water and 250 kg of ethanol containing 0.1 kg of 37 wt% hydrochloric acid, and the mixture was subjected to a hydrolysis-condensation reaction at 60 °C for 2 h. Then, 6 kg of benzimidazole was added, and the mixture was heated to 70 °C and reacted for 1 h. After the reaction was completed, water and ethanol were removed by distillation to obtain a lubricant.

[0118] Table 1: Detection data of the examples and comparative examples

[0119]

[0120] Based on the data analysis of the above embodiments and comparative examples, the copper strip prepared by the present invention has high purity, low oxygen content, high conductivity, and excellent mechanical properties, meeting the technical requirements of high-end fields for high-purity, high-conductivity, oxygen-free copper strips.

[0121] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A short-process forming process for continuous casting and extrusion of wide copper strip, characterized in that: The operating steps are as follows: S1 upward continuous casting: After preheating and drying the high-purity cathode copper, it is melted in the smelting device. Charcoal and graphite flakes are used to cover the surface of the copper liquid, and it is degassed, deoxidized and stirred online. Then, the copper rod is drawn upward by the traction unit. S2 Continuous Extrusion: The copper rod obtained from the upward continuous casting is used as the extrusion material and is continuously extruded 3 times between the extrusion wheel and the compaction wheel; S3 rolling: Using a four-roll mill, the copper strip billet is rolled in 5 passes with pass rates of 46%, 48%, 47%, 49%, and 48%, respectively, ultimately rolling the copper strip to a thickness of 0.3 mm. S4 Annealing: The rolled copper strip is annealed in a gas-protected bright annealing furnace at a temperature of 300-350℃ for 3-5 hours. S5 post-treatment: The annealed copper strip is first cleaned and passivated, then 1-5 parts by weight of a lanthanum(III)-silane-benzimidazole lubricant solution containing 5-10 wt% is sprayed onto the surface of 70-100 parts by weight of the copper strip, and dried; then cut to obtain a wide copper strip. The lanthanum(III)-silane-benzimidazole lubricant is prepared by reacting vinyltriethoxysilane, hydrochloric acid, deionized water, ethanol mixture, benzimidazole, and lanthanum(III) nitrate hexahydrate.

2. The short-process forming process for large-width copper strip continuous casting-continuous extrusion as described in claim 1, characterized in that: The S1 smelting apparatus includes a smelting furnace and a holding furnace; the temperature of the smelting furnace is 1150-1155℃, and it is covered with dried charcoal with a covering thickness of 120-150mm; the temperature of the holding furnace is 1145-1150℃, and it is covered with graphite flakes with a covering thickness of 30-35mm.

3. The short-process forming process for large-width copper strip continuous casting-continuous extrusion as described in claim 1, characterized in that: In the first continuous extrusion of the three extrusions in S2, the rotation speed is 6-7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 0.95 mm, the extrusion temperature is 710-720℃, and the pressure is 1100-1200 MPa.

4. The short-process forming process for large-width copper strip continuous casting-continuous extrusion as described in claim 1, characterized in that: In the second continuous extrusion of the three consecutive extrusions in S2, the rotation speed is 6-7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.05 mm, the extrusion temperature is 720-730℃, and the pressure is 1000-1100 MPa.

5. The short-process forming process for continuous casting-extrusion of wide copper strip as described in claim 1, characterized in that: In the S2 process, the third continuous extrusion speed is 6-7 r / min, the gap between the extrusion wheel and the compaction wheel is adjusted to 1.15 mm, the extrusion temperature is 700-710℃, and the pressure is 950-1050 MPa.

6. The short-process forming process for continuous casting-extrusion of wide copper strip as described in claim 1, characterized in that: The preparation method of the lanthanum(III)-silane-benzimidazole lubricant is as follows: According to the mass fraction, 15-20 parts of vinyltriethoxysilane were added to a mixture of 200-300 parts of deionized water and 250-350 parts of ethanol containing 0.1-0.4 parts of 37wt% hydrochloric acid, and the mixture was subjected to a hydrolysis-condensation reaction at 60-70℃ for 2-3 hours. Then, 6-10 parts of benzimidazole were added, and the temperature was raised to 70-80℃ for 1-3 hours. After the reaction was completed, the system was cooled to 40-50℃, and 0.02-0.07 parts of lanthanum(III) nitrate hexahydrate were added. The reaction was continued for 2-3 hours, and water and ethanol were removed by distillation to obtain lanthanum(III)-silane-benzimidazole lubricant.

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