Application of twist-free controlled-cooling hot-rolled 86C wire rod in development type extra-high-strength steel cord

Abstract

The invention discloses an application of a twist-free controlled-cooling hot-rolled 86C wire rod in a developed extra-high-strength steel cord. The application comprises the following steps: (1) drawing the 86C twist-free controlled-cooling hot-rolled wire rod with the diameter of 5.5 mm to obtain a roughly drawn steel wire with the diameter of 2.90-3.25 mm; (2) drawing the heavy drawn steel wire by using a servo direct-driven wire drawing machine to obtain a medium drawn steel wire with the diameter of 1.25-2.50 mm; (3) treating the medium-drawn steel wire to obtain a brass-plated steel wire; and (4) drawing the brass-plated steel wire into a wet-drawn steel wire with the diameter of 0.18-0.35 mm through wet drawing equipment, sequentially passing through a traction wheel for 0.5 circle, a B-type straightener, a traction wheel and a branching wheel for 5 circles, carrying out a double-wire process, and taking up. And the sorbite conversion rate and the drawing performance are improved, high plasticity and high strength of the material are achieved, the problems that the steel wire strength is low due to the fact that the carbon content of the wire rod is too low and ferritic structures are generated can be avoided, and the problems that the plasticity of the wire rod is reduced, the drawing effect is poor and the like due to the fact that the carbon content of the wire rod is too high and a large number of hypereutectoid cementite structures are generated can be solved.

Description

Technical Field

[0001] The invention relates to a new application of a non-torsion controlled cold-hot rolled 86C wire rod, and in particular to an application of a non-torsion controlled cold-hot rolled 86C wire rod in a development type ultra-high strength steel cord. Background Art

[0002] Lightweighting is not only an important measure to cope with increasingly stringent carbon emission regulations, but also an effective way to improve vehicle performance. It can effectively promote energy conservation and emission reduction in the domestic automobile industry and achieve steady improvement and rapid development of my country's new energy vehicle industry.

[0003] The development direction of tires is high strength and light weight. As the core component of tires, the belt layer plays the role of buffering and tightening the carcass. Therefore, the belt layer should use high-strength and high-modulus steel cords. As the raw material for the belt layer of radial tires, ultra-high-strength (UT) steel cords can reduce the arrangement density of steel cords in the cord fabric, reduce the amount of rubber and steel wire, and improve the stability of the tire during use; at the same time, open ultra-high-strength steel cords have good rubber permeability, adhesion and appropriate stiffness, which can greatly improve the fatigue resistance of PCR tires, thereby reducing the rolling resistance of tires, improving the comprehensive performance of tires, and realizing the lightweight development of tires.

[0004] To improve the strength of steel cord wire, the carbon content of the steel wire is usually increased to increase the work hardening rate and strength. Generally, the carbon content of the wire rod is increased from 0.8% to 0.9%, thereby increasing the strength of the steel wire. However, the organizational state of the steel wire also changes, from eutectoid steel to hypereutectoid steel, which is prone to problems such as hypereutectoid network cementite and center segregation, thereby reducing the plasticity of the wire rod and increasing the risk of wire breakage during drawing. Although the addition of trace elements such as chromium can significantly improve the plasticity of the wire rod, the cost of producing open ultra-high strength steel cords also increases. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes an application of torsion-free controlled cold-rolled 86C wire rod in the development of ultra-high-strength steel cord, which controls the carbon content of the wire rod to about 0.86%, improves the troostite conversion rate and drawing performance, and achieves high plasticity and high strength of the material. It can avoid the wire rod carbon content being too low, producing ferrite structure, resulting in low steel wire strength, and can also avoid the wire rod carbon content being too high, producing a large amount of hypereutectoid cementite structure, resulting in reduced wire rod plasticity, poor drawing effect and other problems; at the same time, under the premise of ensuring that product quality and performance meet customer standards, reasonable optimization of wet drawing process die chain sequencing and lubricating liquid control index management can effectively improve the drawing effect of the steel wire, reduce the wire breakage rate in the cord twisting process, and thus improve the yield rate.

[0006] The technical solution adopted by the present invention is: application of a non-torsion controlled cold-hot rolled 86C wire rod in the development of ultra-high strength steel cord, (1) 86C non-torsion controlled cold and hot rolled wire rod with a diameter of 5.5 mm was drawn to obtain a rough drawn steel wire with a diameter of 2.90-3.25 mm; (2) using a servo direct-drive wire drawing machine to draw the large-drawn steel wire to obtain a medium-drawn steel wire with a diameter of 1.25 mm to 2.50 mm; (2) Processing the middle drawn steel wire to obtain brass plated steel wire; (3) Use wet drawing equipment to pull the brass-plated steel wire to a diameter of 0.18~0.35 mm wet-drawn steel wire, the drawing process of the wet-drawn equipment: the steel wire passes through the 2# and 1# tower wheels in turn, and is wound alternately according to 3.5 turns, and 1-10 single-mode drawing is carried out. The drawn steel wire passes through the guide wheel and is wound alternately on the 4# and 3# tower wheels in turn, 1.5 turns of winding for the 12th pass, 2.5 turns of winding for the 11th pass and 13-23rd passes, and 11-20 single-mode drawing is carried out, the 21st-22nd passes are double-mode, the 23rd pass is a split die and an outlet die, the difference between the die diameter of the sub-die and the die diameter of the previous pass is greater than the difference between the die diameter of this pass and the die diameter of the sub-die, the compression rate of the split die is 2.0-3.0 times that of the compression rate of the outlet die, and the steel wire is drawn through the finished die in sequence: 0.5 turns of traction wheel, B-type straightener, 5 turns of traction wheel + dividing wheel, double-wire process, and wire collection.

[0007] On the basis of the above scheme, as a preferred embodiment, the carbon equivalent CEQ of 86C non-torsion controlled cold and hot rolled wire rod is controlled at 0.87%~0.93%, and the composition of the wire rod is calculated by mass percentage, including: C: 0.85%~0.87%, Si: 0.15%~0.30%, Mn: 0.46%~0.60%, P: ≤0.020%, S: ≤0.025%, Cr: ≤0.08%, Ni: ≤0.08%, Cu: ≤0.08%, Al: ≤0.008%, and the balance is Fe and unavoidable impurities. The total decarburization layer depth is ≤0.09mm, the sorbite content is ≥85%, and the center segregation is ≤3 levels.

[0008] On the basis of the above scheme, as a preferred embodiment, after the wire rod passes through a descaling box to remove the surface oxide scale, it is pickled, rinsed with water, boron coated, and drawn by a servo direct-drive wire drawing machine with 5 dies (4.96-4.42-3.96-3.58-3.25) in sequence to obtain a Φ3.25mm coarse drawn steel wire with a stable surface residual coating, which is then taken up onto a take-up rack.

[0009] On the basis of the above scheme, as a preferred embodiment, the coarse-drawn steel wire is pulled to the servo direct-drive wire drawing machine by a wire take-up frame, and is drawn through 8 dies (2.96-2.65-2.39-2.17-1.98-1.81-1.66-1.53) to obtain a Φ1.53mm medium-drawn steel wire, which is then taken up onto the I-shaped wheel.

[0010] On the basis of the above scheme, as a preferred embodiment, the Φ1.53 mm medium-drawn steel wire is degreased, heated in a heating furnace, AQ quenched, water cooled, pickled, rinsed with water, copper plated, rinsed with water, galvanized, rinsed with water, washed with hot water, medium frequency diffused, water cooled, washed with phosphoric acid, rinsed with water, soap dipped, and finally wound onto an I-shaped wheel in the alloy process to obtain a Φ1.53 mm brass-plated steel wire. The brass coating thickness on the surface of the steel wire is 2 um, the coating weight is 4.2 g / kg, the copper content in the coating is 63.3%, and the tensile strength is 1330 N / mm 2 .

[0011] On the basis of the above scheme, as a preferred embodiment, a double-wire process is adopted: the wires coming out of the outlet dies of two or three die chains pass through the corresponding guide wheels and then are wound on the bobbin through the common guide wheel. The common guide wheel is a guide wheel with a flat-bottom groove. When there are two wires, the width of the flat-bottom groove is 2 times the diameter of the steel wire + 0.012mm. When there are three steel wires, the width of the flat-bottom groove is 3 times the diameter of the steel wire + 0.012mm.

[0012] On the basis of the above scheme, as a preference, the lubricating liquid system of the wet pulling equipment includes a liquid return tank connected to the wet pulling machine, the liquid return tank is connected to the sedimentation tank, the sedimentation tank is connected to the copper separator through a first pipe, the copper separator is connected to the paper filter through a second pipe, the paper filter is connected to the heat exchanger through a third pipe, the heat exchanger is connected to the wet pulling machine through a fourth pipe, the sedimentation tank is connected to the heat exchanger through a fifth pipe, the sedimentation tank is connected to the paper filter through a sixth pipe, the copper separator is connected to the heat exchanger through a seventh pipe, the first pipe has a valve 1#, the second pipe has a valve 2#, the fifth pipe has a valve 3#, the sixth pipe has a valve 4#, and the seventh pipe has a valve 5#.

[0013] On the basis of the above scheme, as a preferred embodiment, when the lubricating fluid system is working, samples are manually taken from the wet drawing machine, and the test results after sampling include four situations: copper ions exceed the standard, impurities exceed the standard, copper ions and impurities exceed the standard, and copper ions and impurities do not exceed the standard: When the copper ion exceeds the standard, valve 3#, valve 2#, and valve 4# are closed, and valve 1# and valve 5# are opened; When impurities exceed the standard, valves 1#, 2#, 3#, and 5# are closed, and valve 4# is opened; When copper ions and impurities exceed the standard, valves 3#, 4#, and 5# are closed, and valves 1# and 2# are opened; When copper ions and impurities are within the limit, valves 1#, 2#, 4#, and 5# are closed, and valve 3# is opened.

[0014] Compared with the prior art, the present invention has the following beneficial effects: the non-torsion controlled cold and hot rolling of 86C wire rod actually controls the carbon content of the wire rod to about 0.86%, avoiding excessively high carbon content of the wire rod and producing a large amount of hypereutectoid cementite structure, thereby improving the troostite conversion rate and drawing performance; at the same time, under the premise of ensuring that product quality and performance meet customer standards, the reasonable optimization of the wet drawing process die chain sequencing and lubricating liquid control index management can effectively improve the drawing effect of the steel wire, reduce the friction between the steel wire and the die chain, adhesion slip and wet drawing die consumption, improve the surface quality of the steel wire, and reduce the wire breakage rate in the cord twisting process, making an important contribution to the development of low-carbon, lightweight green tires. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the tower pulley.

[0016] Figure 2 It is the elongation of each pass of wet-drawn single-filament Φ0.225mm mold chain.

[0017] Figure 3 It is a flow chart of the lubricating fluid system.

[0018] Figure 4 This is the fracture morphology of the finished cord 4x0.225 OC UT; Figure 5 This is a comparison chart of the wire breakage rate of the steel cord obtained in the embodiment of the present invention in the wet drawing process and the original process, 1-original process; 2-present invention; Figure 6 This is a comparison chart of the broken wire rate of the steel cord obtained by the embodiment of the present invention in the cord process and the original process, 1-original process; 2-present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described below by way of examples, but the scope of the present invention is not limited thereto.

[0020] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0021] Taking the production of 4x0.225 OC UT open type ultra-high strength steel cord as an example, the specific steps include: (1) Using Φ5.5mm 86C wire rod as raw material, the carbon equivalent CEQ is 0.89%, and the composition of the wire rod is calculated by mass percentage, including: C: 0.86%, Si: 0.20%, Mn: 0.51%, P: 0.009%, S: 0.012%, Cr: 0.04%, Ni: 0.02%, Cu: 0.02%, Al: 0.001%, and the balance is Fe and unavoidable impurities. The total decarburized layer depth is 0.06mm, the troostite content is 90%, and the center segregation is level 3; (2) The Φ5.5 mm 86C non-torsion controlled cold and hot rolled wire rod is unwound by a C-type hook, and the wire rod is passed through a descaling box to remove the surface oxide scale, and then pickled, rinsed with water, coated with boron, and drawn by a servo direct-drive wire drawing machine with 5 passes of dies (4.96-4.42-3.96-3.58-3.25) to obtain a Φ3.25 mm coarse drawn steel wire with a stable surface residual coating, and then the wire is taken up on a take-up rack; (3) The above-mentioned Φ3.25 mm thick drawn steel wire is pulled onto a servo direct-drive wire drawing machine by a wire take-up frame, and is drawn through 8 passes of dies (2.96-2.65-2.39-2.17-1.98-1.81-1.66-1.53) to obtain a Φ1.53 mm medium drawn steel wire with stable roughness and good surface quality, and then the wire is taken up onto an I-shaped wheel; (4) The above-mentioned Φ1.53 mm medium-drawn steel wire is subjected to degreasing, heating in a heating furnace, AQ quenching, water cooling, pickling, water rinsing, copper plating, water rinsing, galvanizing, water rinsing, hot water washing, medium frequency diffusion, water cooling, phosphoric acid washing, water rinsing, soap immersion, and finally winding onto an I-shaped wheel in the alloy process to obtain a Φ1.53 mm brass-plated steel wire. The brass coating thickness on the surface of the steel wire is about 2 um, the coating weight is about 4.2 g / kg, the copper content in the coating is about 63.3%, and the tensile strength is 1330 N / mm 2 about; (5) The wet drawing equipment uses 23 passes of tungsten carbide die drawing to draw Φ1.53mm brass-plated steel wire into Φ0.225mm wet-drawn single wire. The drawing process mainly involves the following components: tower wheel (1~4#), guide wheel, finished product die, traction wheel, straightener, wire dividing wheel, and wire take-up. The drawing process mainly includes: fixing the wire drawing die to the die pit, and after the steel wire passes through the wire drawing die, it is wound on the tower wheel for multiple turns and drawn through the finished product die for multiple passes to obtain the target wire diameter. Main process steps: the steel wire is wound alternately on the 2# and 1# tower wheels for 3.5 turns, and single-mode drawing is performed for 1-10 times. The drawn steel wire passes through the guide wheel and is wound alternately on the 4# and 3# tower wheels in turn: 1.5 turns on the 12th pass, 2.5 turns on the 11th pass and 13-23rd pass, and single-mode drawing is performed for 11-20 times; the 21st and 22nd passes are double-mode, the 23rd pass is a split die and an exit die, and the 21st and 22nd passes are double-mode: the split die is located between the previous pass die and the current pass die, and the compression rate of the split die can be divided into two, and the compression rate of the split die is greater than the compression rate of the current pass; the split die is located between the previous pass die and the exit die, and the compression rate of the split die is 2.0-3 (2.5) times that of the exit die, with a long service life and cost savings. After being drawn through the finished die, the steel wire passes through the following processes in sequence: 0.5 turns of traction wheel → B-type straightener → 5 turns of traction wheel + wire dividing wheel → double wire process → wire winding. Based on the above improvements in wet drawing process, the service life of the wire drawing die chain can be significantly improved, the risk of exceeding the steel wire diameter can be reduced, and high-quality wet-drawn steel wire can be provided for the cord.

[0022]

[0023] Table 1: Ranking of wet drawn monofilament Φ0.225mm die chains

[0024] Table 2. Use time of wire drawing dies with different compression ratios between outlet die and split die Double-wire process: The wires coming out of the outlet dies of two or three die chains pass through the corresponding guide wheels and then are wound on the bobbin through the common guide wheel. The common guide wheel is a guide wheel with a flat-bottom groove. When there are two wires, the width of the flat-bottom groove is 2 times the diameter of the steel wire + 0.012mm. When there are three steel wires, the width of the flat-bottom groove is 3 times the diameter of the steel wire + 0.012mm. The flat-bottom groove design is adopted to increase the groove spacing, reduce the risk of steel wire scratches, and prevent the steel wire from tangling.

[0025] The lubricating fluid system of the wet drawing equipment includes a liquid return tank connected to the wet drawing machine, the liquid return tank is connected to the sedimentation tank, the sedimentation tank is connected to the copper separator through the first pipeline, the copper separator is connected to the paper filter through the second pipeline, the paper filter is connected to the heat exchanger through the third pipeline, the heat exchanger is connected to the wet drawing machine through the fourth pipeline, the sedimentation tank is connected to the heat exchanger through the fifth pipeline, the sedimentation tank is connected to the paper filter through the sixth pipeline, the copper separator is connected to the heat exchanger through the seventh pipeline, the first pipeline is provided with a valve 1#, the second pipeline is provided with a valve 2#, the fifth pipeline is provided with a valve 3#, the sixth pipeline is provided with a valve 4#, and the seventh pipeline is provided with a valve 5#. When the lubricating fluid system is working, samples are manually taken from the wet drawing machine, and the test results after sampling include four situations: copper ions exceed the standard, impurities exceed the standard, copper ions and impurities exceed the standard, and copper ions and impurities do not exceed the standard: When the copper ion exceeds the standard, valve 3#, valve 2#, and valve 4# are closed, and valve 1# and valve 5# are opened; When impurities exceed the standard, valves 1#, 2#, 3#, and 5# are closed, and valve 4# is opened; When copper ions and impurities exceed the standard, valves 3#, 4#, and 5# are closed, and valves 1# and 2# are opened; When copper ions and impurities are within the limit, valves 1#, 2#, 4#, and 5# are closed, and valve 3# is opened.

[0026] After using for a period of time, a portion of the lubricating fluid is discarded and the original fluid is added to the return liquid pool for replenishment. Bactericides (chemicals) are regularly added to the return liquid pool for sterilization.

[0027] The lubricant can form a layer of pressure-resistant lubricant between the steel wire and the wire drawing die, improve the steel wire drawing effect, reduce the wet drawing die consumption and the risk of scratches and wire breakage on the steel wire surface. The wet drawing lubricant (Solvay SUPERSOL ADM U V2 wire drawing lubricant) is a water-soluble self-reactive lubricant mainly composed of fatty acids, POE alkyl phosphates, surfactants, and phosphoric acid. The active ingredient is a metal complex formed by the reaction of the steel wire coating with the lubricant components EDA, P and fatty acids, and forms a phosphoric acid film and an oily film, thereby improving heat resistance and pressure resistance and low friction coefficient. The lubricant is recycled through the lubrication station system, and the lubricant is kept in a mature liquid state by adding new liquid and discarding old liquid, providing the best conditions for steel wire drawing. By optimizing the above wet drawing process, the wire breakage rate of the steel wire in the 22nd pass and the bulging defect of the finished product are reduced, providing high-quality steel wire for the cord process. The wire breakage rate in the wet drawing process is reduced from 1.0 times / ton to 0.5 times / ton, a 50% decrease compared to the original process.

[0028] During use, the lubricating fluid system is used to maintain the copper ion content in the lubricating fluid at 400-800 ppm and the zinc ion content in the lubricating fluid at 400-900 ppm.

[0029] (6) Combined with the above process optimization, the Φ1.53 mm brass-plated steel wire is drawn into a wet-drawn single wire with a diameter of Φ0.225 mm, and then a wet-drawn double wire is obtained through a double-wire process, which is used to produce 4x0.225 OC UT open type ultra-high strength steel cord.

[0030] Two wet-drawn double wires are twisted into the required finished product 4x0.225 OC UT. The wire breakage rate is reduced from 2.5 times / ton to 1.5 times / ton, a 40% decrease compared with the original process. The average breaking tensile force of the finished cord is 598N (standard > 570N), and other performances meet customer requirements.

[0031] (7) Steel cords that have passed the inspection must be packaged and stored according to different types and specifications.

[0032] In combination with the above 4x0.225 OC UT embodiment, it can be seen that the open type ultra-high strength steel cord for PCR tires obtained by the method of the present invention, under the premise of reducing the carbon content of the wire rod and optimizing the wet drawing process and lubrication conditions, not only ensures that the performance of the finished product meets customer requirements, but also reduces the wire breakage rate in the entire production process and improves the yield rate.

[0033] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. Application of non-torsion controlled cold-rolled 86C wire rod in development type ultra-high strength steel cord, characterized in that: (1) 86C non-torsion controlled cold and hot rolled wire rod with a diameter of 5.5 mm was drawn to obtain a rough drawn steel wire with a diameter of 2.90-3.25 mm; (2) using a servo direct-drive wire drawing machine to draw the large-drawn steel wire to obtain a medium-drawn steel wire with a diameter of 1.25 mm to 2.50 mm; (3) Processing the middle drawn steel wire to obtain brass plated steel wire; (4) Use wet drawing equipment to pull the brass-plated steel wire to a diameter of 0.18~0.35 mm wet-drawn steel wire, the drawing process of the wet-drawn equipment: the steel wire passes through the 2# and 1# tower wheels in turn, and is wound alternately according to 3.5 turns, and 1-10 single-mode drawing is carried out. The drawn steel wire passes through the guide wheel and is wound alternately on the 4# and 3# tower wheels in turn, 1.5 turns of winding for the 12th pass, 2.5 turns of winding for the 11th pass and 13-23rd passes, and 11-20 single-mode drawing is carried out, the 21st-22nd passes are double-mode, the 23rd pass is a split die and an outlet die, the difference between the die diameter of the sub-die and the die diameter of the previous pass is greater than the difference between the die diameter of this pass and the die diameter of the sub-die, the compression rate of the split die is 2.0-3.0 times that of the compression rate of the outlet die, and the steel wire is drawn through the finished die in sequence: 0.5 turns of traction wheel, B-type straightener, 5 turns of traction wheel + dividing wheel, double-wire process, and wire collection.

2. The application of the non-torsion controlled cold-rolled 86C wire rod in the development of ultra-high strength steel cord as claimed in claim 1, characterized in that: The carbon equivalent CEQ of 86C non-torsion controlled cold and hot rolled wire rod is controlled at 0.87%~0.93%. The composition of the wire rod is calculated by mass percentage, including: C: 0.85%~0.87%, Si: 0.15%~0.30%, Mn: 0.46%~0.60%, P: ≤0.020%, S: ≤0.025%, Cr: ≤0.08%, Ni: ≤0.08%, Cu: ≤0.08%, Al: ≤0.008%, and the balance is Fe and unavoidable impurities. The total decarburization layer depth is ≤0.09mm, the sorbite content is ≥85%, and the center segregation is ≤3 levels.

3. The application of the non-torsion controlled cold-hot rolled 86C wire rod in the development type ultra-high strength steel cord as claimed in claim 1, characterized in that: After the wire rod passes through the descaling box to remove the surface oxide scale, it is pickled, rinsed with water, coated with boron, and drawn by a servo direct-drive wire drawing machine with 5 dies (4.96-4.42-3.96-3.58-3.25) in sequence to obtain a Φ3.25mm coarse drawn steel wire with a stable surface residual coating, which is then taken up onto the take-up rack.

4. The application of the non-torsion controlled cold-rolled 86C wire rod in the development type ultra-high strength steel cord as claimed in claim 3, characterized in that: The rough drawn steel wire is pulled to the servo direct-drive wire drawing machine by the take-up frame, and is drawn through 8 dies (2.96-2.65-2.39-2.17-1.98-1.81-1.66-1.53) to obtain the Φ1.53mm medium-drawn steel wire, which is then taken up onto the I-shaped wheel.

5. The application of the non-torsion controlled cold-rolled 86C wire rod in the development type ultra-high strength steel cord as claimed in claim 1, characterized in that: The Φ1.53mm medium-drawn steel wire is degreased, heated in a heating furnace, AQ quenched, water cooled, pickled, rinsed, copper plated, rinsed, galvanized, rinsed, washed with hot water, intermediate frequency diffused, cooled, washed with phosphoric acid, rinsed with water, soaked in soap, and finally wound onto an I-shaped wheel to obtain a Φ1.53mm brass-plated steel wire. The brass coating thickness on the steel wire surface is 2um, the coating weight is 4.2 g / kg, the copper content in the coating is 63.3%, and the tensile strength is 1330 N / mm 2 .

6. Application of the non-torsion controlled cold-rolled 86C wire rod in the development of ultra-high strength steel cord as claimed in claim 1, characterized in that: Double-wire process: The wires coming out of the outlet dies of two or three die chains pass through the corresponding guide wheels and then are wound on the bobbin through the common guide wheel. The common guide wheel is a guide wheel with a flat-bottom groove. When there are two wires, the width of the flat-bottom groove is 2 times the diameter of the steel wire + 0.012mm. When there are three steel wires, the width of the flat-bottom groove is 3 times the diameter of the steel wire + 0.012mm.

7. Application of the non-torsion controlled cold-rolled 86C wire rod in the development of ultra-high strength steel cord as claimed in claim 1, characterized in that: The lubricating liquid system of the wet pulling equipment includes a liquid return tank connected to the wet pulling machine, the liquid return tank is connected to the sedimentation tank, the sedimentation tank is connected to the copper separator through a first pipe, the copper separator is connected to the paper filter through a second pipe, the paper filter is connected to the heat exchanger through a third pipe, the heat exchanger is connected to the wet pulling machine through a fourth pipe, the sedimentation tank is connected to the heat exchanger through a fifth pipe, the sedimentation tank is connected to the paper filter through a sixth pipe, the copper separator is connected to the heat exchanger through a seventh pipe, the first pipe is provided with a valve 1#, the second pipe is provided with a valve 2#, the fifth pipe is provided with a valve 3#, the sixth pipe is provided with a valve 4#, and the seventh pipe is provided with a valve 5#.

8. The application of the non-torsion controlled cold-rolled 86C wire rod in the development type ultra-high strength steel cord as claimed in claim 1, characterized in that: When the lubricating fluid system is working, samples are taken manually from (to) the wet drawing machine. The test results after sampling include four situations: copper ions exceed the standard, impurities exceed the standard, copper ions and impurities exceed the standard, and copper ions and impurities do not exceed the standard: When the copper ion exceeds the standard, valve 3#, valve 2#, and valve 4# are closed, and valve 1# and valve 5# are opened; When impurities exceed the standard, valves 1#, 2#, 3#, and 5# are closed, and valve 4# is opened; When copper ions and impurities exceed the standard, valves 3#, 4#, and 5# are closed, and valves 1# and 2# are opened; When copper ions and impurities are within the limit, valves 1#, 2#, 4#, and 5# are closed, and valve 3# is opened.

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