High-strength hot-rolled wire rod for steel wire rope and method for manufacturing the same

Abstract

The application discloses a kind of high-strength steel wire rope hot rolled wire rod and preparation method thereof, method includes: sequentially carrying out converter smelting, secondary refining outside furnace, and the required casting blank is prepared by continuous casting, and then sequentially carrying out casting blank heating, high-pressure water dephosphorization, high-speed wire rolling, wire spooling machine wire spooling, Stelmor air cooling line controlled cooling, coiling and packing and are prepared high-strength steel wire rope hot rolled wire rod;Wherein, during the rolling process, multiple water tanks are divided into multiple groups, along the direction of rolling production line, the opening degree, outlet pressure and flow of multiple water tanks gradually decrease;During the Stelmor air cooling line controlled cooling process, multiple fans are divided into multiple groups, along the direction of Stelmor air cooling line, the opening degree of multiple fans gradually decreases.The application mainly includes high-speed wire rolling and controlled rolling and controlled cooling process, by the control of casting blank heating temperature, heating time, wire spooling temperature after rolling and sectional controlled cooling technology combination, finally obtain the hot rolled wire rod with good performance.

Description

Technical Field

[0001] This invention relates to the field of iron and steel smelting technology, and in particular to a hot-rolled wire rod for high-strength steel wire rope and its preparation method. Background Technology

[0002] Steel wire ropes are widely used in many fields such as elevator hoisting, truck hoisting, port loading and unloading, and mine hoisting. Currently, ordinary steel wire ropes with a strength below 1770MPa are widely used, but with the continuous development of my country's machinery industry, the market demand for high-strength steel wire ropes with a strength of 1870MPa and above is increasing day by day.

[0003] High-strength steel wire ropes not only require high nominal tensile strength but also stringent requirements for torsional and bending properties to ensure safety and long service life. This places new demands on the wire rods used in their production. To improve the strength of the wire rods, alloys are typically added or heat treatment is applied. However, adding alloys increases production costs and can reduce plasticity, leading to brittle fracture during the drawing and twisting processes. Heat treatment complicates the wire rope manufacturing process and further increases production costs.

[0004] In view of this, improvements should be made to the existing technology. Summary of the Invention

[0005] The main objective of this invention is to provide a hot-rolled wire rod for high-strength steel wire rope and its preparation method. The method mainly includes high-speed wire rolling and controlled rolling and cooling processes. By controlling the billet heating temperature, heating time, and post-rolling wire drawing temperature, as well as combining segmented controlled cooling technology, a hot-rolled wire rod with excellent performance is finally obtained. This hot-rolled wire rod can be used to make high-strength steel wire rope with a nominal tensile strength ≥1870MPa, torsion cycles ≥25 times, and bending cycles ≥15 times.

[0006] According to one aspect of the present invention, a method for preparing hot-rolled wire rod for high-strength steel wire rope is provided, comprising: sequentially performing converter smelting, ladle refining, and continuous casting to obtain the required billet; then sequentially performing billet heating, high-pressure water descaling, high-speed wire rolling, wire drawing on a wire rod mill, controlled cooling on a Steyrmo air-cooling line, coiling, and packaging to obtain hot-rolled wire rod for high-strength steel wire rope; wherein, during the rolling process, multiple water tanks are divided into multiple groups, and along the direction of the rolling production line, the opening degree, outlet pressure, and flow rate of the multiple groups of water tanks gradually decrease; during the controlled cooling process on the Steyrmo air-cooling line, multiple fans are divided into multiple groups, and along the direction of the Steyrmo air-cooling line, the opening degree of the multiple groups of fans gradually decreases.

[0007] According to one embodiment of the present invention, the chemical composition of the hot-rolled wire rod for high-strength steel wire rope, by weight percentage, is as follows: C: 0.60%–0.70%, Si: 0.40%–0.80%, Mn: 0.30%–0.60%, P≤0.015%, S≤0.010%, Cr: 0.10%–0.30%; the remainder being Fe and unavoidable impurities.

[0008] According to one embodiment of the present invention, during continuous casting, the ladle of molten steel is superheated to 10-25°C, and casting is carried out at a constant rate, with the center carbon segregation of the billet being 0.98-1.06.

[0009] According to one embodiment of the present invention, the billet is heated by a heating furnace, the temperature range of the soaking zone of the heating furnace is 1000~1050℃, and the heating time is t=(0.8~1.2)H, where H is the thickness of the billet.

[0010] According to one embodiment of the present invention, after being heated in a furnace, the billet is descaled by high-pressure water and then rolled into wire rod at a high-speed wire rod with an initial rolling temperature of 920-980°C. The rolling process is controlled by cooling water.

[0011] According to one embodiment of the present invention, during the rolling process, the opening degree of water tank #1 is 20-30%, the outlet water pressure is 3-4 bar, and the flow rate is 20-30 m³ / h. 3 / h, the opening degree of water tank #2 is 15~25%, the outlet water pressure is 2.5~3.5 bar, and the flow rate is 15~25 m³ / h. 3 / h, the opening degree of water tank #3 is 15~25%, the outlet water pressure is 2.5~3.5 bar, and the flow rate is 15~25 m³ / h. 3 / h, the opening degree of water tank #4 is 15~25%, the outlet water pressure is 1.5~2.5 bar, and the flow rate is 15~20 m³ / h. 3 / h, No. 5 water tank opening degree ≤10%, outlet water pressure ≤1.5 bar, flow rate ≤10 m³ / h 3 / h, the temperature before spinning is 850~885℃.

[0012] According to one embodiment of the present invention, the coiled wire after spinning is cooled in a controlled manner on a Stellmore air-cooling line. The initial speed of the roller conveyor is 0.6~0.7m / s, and the speed of the roller conveyor sections 2 to 13 increases by 0.01~0.03m / s in each section.

[0013] According to one embodiment of the present invention, in the Stellmore air-cooled line, the opening degree of fans 1# to 5# is 95~100%, the opening degree of fan 6# is 75~85%, the opening degree of fan 7# is 65~75%, the opening degree of fan 8# is 55~65%, the insulation cover is fully opened, and the opening angle of the Jialing device is 3~8°; when the temperature is rapidly cooled to 600~630°C, the fans and insulation cover are turned off, and slow cooling is carried out at a cooling rate of ≤3°C / s, with the winding temperature ≤450°C.

[0014] According to another aspect of the present invention, a hot-rolled wire rod for high-strength steel wire rope is provided, which is prepared by any of the methods described above.

[0015] According to one embodiment of the present invention, the hot-rolled wire rod for high-strength steel wire rope has a tensile strength ≥1200MPa, an elongation after fracture ≥15%, a reduction of area ≥45%, a microstructure of pearlite + trace ferrite, a sorbite content ≥85%, and no core martensite or grain boundary cementite.

[0016] In a method for preparing hot-rolled wire rod for high-strength steel wire rope according to an embodiment of the present invention, the main processes include high-speed wire rolling and controlled rolling and controlled cooling. By combining the control of billet heating temperature, heating time, post-rolling wire drawing temperature and segmented controlled cooling technology, a hot-rolled wire rod with good performance is finally obtained. The hot-rolled wire rod can be used to make high-strength steel wire rope with a nominal tensile strength ≥1870MPa, torsion cycles ≥25 times, and bending cycles ≥15 times. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some implementation examples of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A process flow diagram of a method for preparing hot-rolled wire rod for high-strength steel wire rope according to an exemplary embodiment of the present invention is shown. Detailed Implementation

[0019] The following detailed description of the embodiments is intended to exemplify the principles of the present invention, but should not be construed as limiting the scope of the invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0020] These embodiments are provided to make this disclosure thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0021] It should be noted that, in the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] It should also be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.

[0023] All terms used in this invention have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0024] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0025] like Figure 1As shown, this invention provides a method for preparing hot-rolled wire rod for high-strength steel wire rope, comprising the following steps: S1, sequentially performing converter smelting, ladle refining, and continuous casting to obtain the required billet; S2, sequentially performing billet heating, high-pressure water descaling, high-speed wire rolling, wire drawing on a wire drawing machine, controlled cooling on a Steyrmo air-cooling line, coiling, and packaging to obtain hot-rolled wire rod for high-strength steel wire rope; wherein, during the rolling process, multiple water tanks are divided into multiple groups, and along the direction of the rolling production line, the opening degree, outlet pressure, and flow rate of the multiple groups of water tanks gradually decrease; during the controlled cooling process on the Steyrmo air-cooling line, multiple fans are divided into multiple groups, and along the direction of the Steyrmo air-cooling line, the opening degree of the multiple groups of fans gradually decreases.

[0026] In the preparation method of hot-rolled wire rod for high-strength steel wire rope according to an embodiment of the present invention, the main processes include high-speed wire rolling and controlled rolling and controlled cooling. By combining the control of billet heating temperature, heating time, post-rolling wire drawing temperature and segmented controlled cooling technology, a hot-rolled wire rod with good performance is finally obtained. The hot-rolled wire rod can be used to make high-strength steel wire rope with a nominal tensile strength ≥1870MPa, torsion cycles ≥25 times, and bending cycles ≥15 times.

[0027] In some specific embodiments, the chemical composition of the hot-rolled wire rod for high-strength steel wire rope, by weight percentage, is as follows: C: 0.60%–0.70%, Si: 0.40%–0.80%, Mn: 0.30%–0.60%, P≤0.015%, S≤0.010%, Cr: 0.10%–0.30%; the remainder being Fe and unavoidable impurities.

[0028] Based on the above embodiments, during continuous casting, the ladle superheats the molten steel to 10–25°C, the casting is carried out at a constant rate, and the carbon segregation at the center of the billet is 0.98–1.06.

[0029] The superheat of molten steel is a crucial factor affecting center segregation in cast billets. Excessive superheat intensifies the growth of columnar crystals and promotes the enrichment of solute elements, thereby increasing center segregation. Therefore, setting a reasonable tundish superheat, such as stabilizing it below 20°C, or even below 15°C, can effectively reduce the degree of carbon segregation in the center of the cast billet and improve its internal quality.

[0030] Constant-speed casting ensures that the billet receives uniform and stable cooling and feeding during solidification, thus avoiding instability in the internal quality of the billet caused by fluctuations in casting speed. Constant-speed casting helps reduce defects such as cracks and porosity inside the billet, improving the overall quality of the billet.

[0031] In some specific embodiments, the billet is heated by a heating furnace, the temperature range of the soaking zone of the heating furnace is 1000~1050℃, and the heating time is t=(0.8~1.2)H, where H is the thickness of the billet.

[0032] Based on the above embodiments, the billet is heated in a furnace, then descaled by high-pressure water, and finally rolled into wire rod at a high-speed wire rod. The initial rolling temperature is 920-980℃, and the rolling process is controlled by cooling water. Specifically, after descaling by high-pressure water, it is rolled into φ6.5mm wire rod.

[0033] In some specific embodiments, during the rolling process, the opening degree of water tank #1 is 20-30%, the outlet water pressure is 3-4 bar, and the flow rate is 20-30 m³ / h. 3 / h, the opening degree of water tank #2 is 15~25%, the outlet water pressure is 2.5~3.5 bar, and the flow rate is 15~25 m³ / h. 3 / h, the opening degree of water tank #3 is 15~25%, the outlet water pressure is 2.5~3.5 bar, and the flow rate is 15~25 m³ / h. 3 / h, the opening degree of water tank #4 is 15~25%, the outlet water pressure is 1.5~2.5 bar, and the flow rate is 15~20 m³ / h. 3 / h, No. 5 water tank opening degree ≤10%, outlet water pressure ≤1.5 bar, flow rate ≤10 m³ / h 3 / h, the temperature before spinning is 850~885℃. Water tanks 1#~5# are set up sequentially along the direction of the rolling production line.

[0034] Specifically, the opening degree of water tank #1 is 25%, the outlet water pressure is 3.5 bar, and the flow rate is 25 m³ / h. 3 / h, Water tank #2 is open at 20%, outlet water pressure is 3.0 bar, and flow rate is 20 m³ / h. 3 / h, water tank #3 is open at 20%, outlet water pressure is 3.0 bar, and flow rate is 20 m³ / h. 3 / h, water tank #4 is open at 20%, outlet water pressure is 2.0 bar, and flow rate is 18 m³ / h. 3 / h, No. 5 water tank opening degree ≤10%, outlet water pressure ≤1.5 bar, flow rate ≤10 m³ / h 3 / h, the temperature before spinning is 850~885℃.

[0035] Based on the above embodiments, the coiled wire after spinning is cooled in a controlled manner on the Stellmore air-cooling line. The initial speed of the roller conveyor is 0.6~0.7m / s, and the speed of the roller conveyor from the 2nd to the 13th section is increased by 0.01~0.03m / s.

[0036] Specifically, the initial speed of the roller conveyor is 0.68 m / s, and the speed of the roller conveyor in sections 2 to 13 increases by 0.02 m / s each section.

[0037] In some specific embodiments, in the Stellmore air-cooled line, the opening degree of fans 1# to 5# is 95~100%, fan 6# is 75~85%, fan 7# is 65~75%, and fan 8# is 55~65%. The insulation cover is fully open, and the opening angle of the Jialing device is 3~8°. When rapidly cooling to 600~630℃, the fans and insulation cover are turned off, and slow cooling is performed at a cooling rate of ≤3℃ / s, with the coil temperature ≤450℃. Fans 1# to 7# are arranged sequentially along the direction of the Stellmore air-cooled line. The flow rate of fans 1# to 4# is 190,000~210,000 m³ / s. 3 / h, the flow rate of fan #5 is 150,000 to 170,000 m³ / h. 3 / h, the flow rate of fan #6 is 120,000 to 130,000 m³ / h. 3 / h, the flow rate of fan #7 is 110,000 to 120,000 m³ / h. 3 / h, the flow rate of fan #8 is 90,000 to 100,000 m³ / h. 3 / h.

[0038] Specifically, the opening degree of fans 1# to 5# is 100%, the opening degree of fan 6# is 80%, the opening degree of fan 7# is 70%, the opening degree of fan 8# is 60%, the insulation cover is fully opened, and the opening angle of the Jialing device is 5°; when the temperature is rapidly cooled to 600-630℃, the fans and insulation cover are turned off, and the temperature is slowly cooled at a cooling rate of ≤3℃ / s, and the winding temperature is ≤450℃.

[0039] This invention also proposes a hot-rolled wire rod for high-strength steel wire rope, which is prepared by the method mentioned in the above technical solution.

[0040] In some specific embodiments, the hot-rolled wire rod for high-strength steel wire rope has a tensile strength ≥1200MPa, an elongation after fracture ≥15%, a reduction of area ≥45%, a microstructure of pearlite + trace ferrite, a sorbite content ≥85%, and no core martensite or grain boundary cementite.

[0041] Wire ropes made from this type of wire rod have a nominal tensile strength ≥1870MPa, a torsion cycle ≥25 times, and a bending cycle ≥15 times.

[0042] One specific application of this invention is as follows:

[0043] Step 1: Obtain the required billet with the required chemical composition through converter smelting, ladle refining, and continuous casting.

[0044] (1) During the continuous casting process of billet preparation, the ladle superheat is 10-25℃, the casting speed is constant, and the carbon segregation degree at the center of the billet is 0.98-1.06.

[0045] (2) Chemical composition of the billet: C 0.60%~0.70%, Si 0.40%~0.80%, Mn 0.30%~0.60%, P≤0.015%, S≤0.010%, Cr 0.10%~0.30%; the remainder is Fe and unavoidable impurities.

[0046] Step 2: The obtained billet is heated in a heating furnace. The temperature of the soaking zone of the heating furnace is 1000-1050℃, and the heating time is t=(0.8-1.2)H, where H is the thickness of the billet.

[0047] Step 3: After being heated in a furnace, the billet is cast, then descaled by high-pressure water, and finally rolled into φ6.5mm wire rod.

[0048] (1) The rolling temperature is 920~980℃.

[0049] (2) During the rolling process, the water cooling box is turned on for water cooling to reduce the temperature of the rolled piece and ensure that the wire drawing temperature is controlled within the required range. The opening degree of water tank #1 is 25%, the outlet water pressure is 3.5 bar, and the flow rate is 25 m³ / h. 3 / h, Water tank #2 is open at 20%, outlet water pressure is 3.0 bar, and flow rate is 20 m³ / h. 3 / h, water tank #3 is open at 20%, outlet water pressure is 3.0 bar, and flow rate is 20 m³ / h. 3 / h, water tank #4 is open at 20%, outlet water pressure is 2.0 bar, and flow rate is 18 m³ / h. 3 / h, No. 5 water tank opening degree ≤10%, outlet water pressure ≤1.5 bar, flow rate ≤10 m³ / h 3 / h, with a spinning temperature of 850~885℃.

[0050] (3) The coiled wire after spinning is cooled under controlled conditions on the Stellmore air-cooling line. The initial speed of the roller conveyor is 0.68 m / s, and the speed of the roller conveyor from the 2nd to the 13th section increases by 0.02 m / s each section. The opening degree of fans 1# to 4# is 100%, and the flow rate is 200,000 m³ / s. 3 / h, the corresponding insulation cover is opened; the No. 5 fan is open at 100%, and the flow rate is 160,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening degree of fan #6 is 80%, and the flow rate is 128,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening degree of fan #7 is 70%, and the flow rate is 112,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the No. 8 fan is open at 60%, with a flow rate of 96,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening angle of the Jialing device is 5°; when the temperature is rapidly cooled to 600~630℃, the fan and the corresponding insulation cover are turned off, and the temperature is slowly cooled at a cooling rate of ≤3℃ / s, with the winding temperature ≤450℃.

[0051] The present invention also proposes a hot-rolled wire rod for high-strength steel wire rope, which is prepared by any of the above technical solutions.

[0052] The hot-rolled wire rod for this high-strength steel wire rope has a tensile strength ≥1200MPa, elongation after fracture ≥15%, reduction of area ≥45%, and a microstructure of pearlite + trace ferrite with a sorbite content ≥85%, and no core martensite or grain boundary cementite.

[0053] The high-strength steel wire rope is made from hot-rolled wire rod and has a nominal tensile strength ≥1870MPa, a torsion cycle ≥25 times, and a bending cycle ≥15 times.

[0054] After the application of this invention, the product quality fully meets the relevant technical requirements and has been sent to users for further processing. Once the user's requirements are met, the annual production volume is expected to be about 10,000 tons. With a profit of 200 yuan per ton of steel, the economic benefit can reach 2 million yuan. It can be promoted and applied in the production of high-strength steel wire rope wire rods and other wire rods in various steel mills, and has good prospects for promotion and application.

[0055] The solution of this application will be described below through specific embodiments.

[0056] Example 1

[0057] A wire factory uses the technology of this invention for production, and the specific implementation is as follows.

[0058] (1) A 200mm×200mm billet was obtained by converter smelting, LF refining and continuous casting. The superheat of the molten steel in the ladle during the continuous casting process was 10~20℃, the casting speed was 1.4m / min, the carbon segregation degree of the center of the billet was 1.03~1.06, and the chemical composition was: C0.60%, Si0.40%, Mn0.60%, P0.015%, S0.008%, Cr0.30%; the remainder was Fe and unavoidable impurities.

[0059] (2) The obtained billet is heated in a heating furnace. The temperature of the soaking zone of the heating furnace is 1000℃ and the heating time is 160min.

[0060] (3) After heating, the billet is descaled by high pressure water and then rolled on a high-speed wire rod at a rolling temperature of 920-940℃.

[0061] (4) During the rolling process, the opening degree of water tank #1 is 25%, the outlet water pressure is 3.5 bar, and the flow rate is 25 m³ / h. 3 / h, Water tank #2 is open at 20%, outlet water pressure is 3.0 bar, and flow rate is 20 m³ / h. 3 / h, water tank #3 is open at 20%, outlet water pressure is 3.0 bar, and flow rate is 20 m³ / h. 3 / h, water tank #4 is open at 20%, outlet water pressure is 2.0 bar, and flow rate is 18 m³ / h. 3 / h, water tank #5 opening degree is 5%, outlet water pressure is 1.0 bar, flow rate is 5 m³ / h. 3 / h, the spinning temperature is 850℃.

[0062] (5) The coiled wire after spinning is cooled on the Steyrmo air-cooling line. The control parameters of the Steyrmo air-cooling line are as follows: the initial speed of the roller conveyor is 0.68 m / s, and the speed of the roller conveyor from the 2nd to the 13th section increases by 0.02 m / s each section; the opening degree of the blowers from No. 1 to No. 4 is 100%, and the flow rate is 200,000 m³ / s. 3 / h, the corresponding insulation cover is opened; the No. 5 fan is open at 100%, and the flow rate is 160,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening degree of fan #6 is 80%, and the flow rate is 128,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening degree of fan #7 is 70%, and the flow rate is 112,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the No. 8 fan is open at 60%, with a flow rate of 96,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening angle of the Jialing device is 5°; when it is rapidly cooled to 600℃, it enters the insulation cover and the fan is turned off. The cooling rate is 1.8℃ / s, and the winding temperature is 400℃.

[0063] (6) The φ6.5mm wire rod obtained by the above method has a tensile strength of 1200MPa, an elongation after fracture of 21%, a reduction of area of ​​50%, and a microstructure of pearlite with trace ferrite and a sorbite content of 85%, without core martensite and grain boundary cementite. The wire rope made from this wire rod has a nominal tensile strength of 1870MPa, a torsion resistance of 33 times, and a bending resistance of 17 times.

[0064] Example 2

[0065] A wire factory uses the technology of this invention for production, and the specific implementation is as follows.

[0066] (1) A 160mm×160mm billet was obtained by converter smelting, LF refining and continuous casting. The superheat of the molten steel in the ladle during the continuous casting process was 15~25℃, the casting speed was 1.8m / min, the carbon segregation degree of the center of the billet was 0.98~1.02, and the chemical composition was: C0.70%, Si0.80%, Mn0.30%, P0.011%, S0.010%, Cr0.10%; the remainder was Fe and unavoidable impurities.

[0067] (2) The obtained billet is heated in a heating furnace. The temperature of the soaking zone of the heating furnace is 1050℃ and the heating time is 192min.

[0068] (3) After heating, the billet is dephosphorized by high pressure water and then rolled on a high-speed wire rod at a rolling temperature of 950-980℃.

[0069] (4) During the rolling process, the opening degree of water tank #1 is 25%, the outlet water pressure is 3.5 bar, and the flow rate is 25 m³ / h. 3 / h, Water tank #2 is open at 20%, outlet water pressure is 3.0 bar, and flow rate is 20 m³ / h. 3 / h, water tank #3 is open at 20%, outlet water pressure is 3.0 bar, and flow rate is 20 m³ / h. 3 / h, water tank #4 is open at 20%, outlet water pressure is 2.0 bar, and flow rate is 18 m³ / h. 3 / h, water tank #5 opening degree is 5%, outlet water pressure ≤1.0 bar, flow rate ≤5 m³ / h 3 / h, the spinning temperature is 885℃.

[0070] (5) The coiled wire after spinning is cooled on the Steyrmo air-cooling line. The control parameters of the Steyrmo air-cooling line are as follows: the initial speed of the roller conveyor is 0.68 m / s, and the speed of the roller conveyor from the 2nd to the 13th section increases by 0.02 m / s each section; the opening degree of the blowers from No. 1 to No. 4 is 100%, and the flow rate is 200,000 m³ / s. 3 / h, the corresponding insulation cover is opened; the No. 5 fan is open at 100%, and the flow rate is 160,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening degree of fan #6 is 80%, and the flow rate is 128,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening degree of fan #7 is 70%, and the flow rate is 112,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the No. 8 fan is open at 60%, with a flow rate of 96,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening angle of the Jialing device is 5°; when it is rapidly cooled to 630℃, it enters the insulation cover and the fan is turned off. The cooling rate is 2.5℃ / s, and the winding temperature is 372℃.

[0071] (6) The φ6.5mm wire rod obtained by the above method has a tensile strength of 1280MPa, an elongation after fracture of 15%, a reduction of area of ​​45%, and a microstructure of pearlite + trace ferrite with a sorbite content of 88%, without core martensite and grain boundary cementite. The wire rope made from this wire rod has a nominal tensile strength of 1920MPa, a torsion resistance of 25 times, and a bending resistance of 16 times.

[0072] Example 3

[0073] A wire factory uses the technology of this invention for production, and the specific implementation is as follows.

[0074] (1) A 150mm×150mm billet was obtained by converter smelting, LF refining and continuous casting. The superheat of the molten steel in the ladle during the continuous casting process was 10~22℃, the casting speed was 2.2m / min, the carbon segregation degree of the center of the billet was 0.98~1.04, and the chemical composition was: C0.66%, Si0.48%, Mn0.53%, P≤0.012%, S≤0.007%, Cr0.18%; the remainder was Fe and unavoidable impurities.

[0075] (2) The obtained billet is heated in a heating furnace. The temperature of the soaking zone of the heating furnace is 1048℃ and the heating time is 180min.

[0076] (3) After heating, the billet is descaled by high pressure water and then rolled on a high-speed wire rod at a rolling temperature of 940-960℃.

[0077] (4) During the rolling process, the opening degree of water tank #1 is 25%, the outlet water pressure is 3.5 bar, and the flow rate is 25 m³ / h. 3 / h, Water tank #2 is open at 20%, outlet water pressure is 3.0 bar, and flow rate is 20 m³ / h. 3 / h, water tank #3 is open at 20%, outlet water pressure is 3.0 bar, and flow rate is 20 m³ / h. 3 / h, water tank #4 is open at 20%, outlet water pressure is 2.0 bar, and flow rate is 18 m³ / h. 3 / h, water tank #5 opening degree is 3%, outlet water pressure is 0.8 bar, flow rate is 3 m³ / h. 3 / h, the spinning temperature is 877℃.

[0078] (5) The coiled wire after spinning is cooled on the Steyrmo air-cooling line. The control parameters of the Steyrmo air-cooling line are as follows: the initial speed of the roller conveyor is 0.68 m / s, and the speed of the roller conveyor from the 2nd to the 13th section increases by 0.02 m / s each section; the opening degree of the blowers from No. 1 to No. 4 is 100%, and the flow rate is 200,000 m³ / s. 3 / h, the corresponding insulation cover is opened; the No. 5 fan is open at 100%, and the flow rate is 160,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening degree of fan #6 is 80%, and the flow rate is 128,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening degree of fan #7 is 70%, and the flow rate is 112,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the No. 8 fan is open at 60%, with a flow rate of 96,000 m³ / h. 3 / h, the corresponding insulation cover is opened; the opening angle of the Jialing device is 5°; when it is rapidly cooled to 630℃, it enters the insulation cover and the fan is turned off. The cooling rate is 2.2℃ / s, and the winding temperature is 397℃.

[0079] (6) The φ6.5mm wire rod obtained by the above method has a tensile strength of 1265MPa, an elongation after fracture of 19%, a reduction of area of ​​42%, and a microstructure of pearlite with trace ferrite and a sorbite content of 86%, without core martensite or grain boundary cementite. The wire rope made from this wire rod has a nominal tensile strength of 1905MPa, a torsion resistance of 30 times, and a bending resistance of 19 times.

[0080] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular.

[0081] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for preparing hot-rolled wire rod for high-strength steel wire rope, characterized in that, include: The process involves sequentially smelting in a converter, refining in a ladle, and continuous casting to obtain the required billet. Then, the billet is sequentially heated, descaled with high-pressure water, rolled in a high-speed wire rod mill, wired using a wire spinneret, cooled in a Steyrmore air-cooling line, coiled, and packaged to produce hot-rolled wire rod for high-strength steel wire rope. During the rolling process, multiple water tanks are divided into multiple groups, and along the rolling production line, the opening degree, outlet pressure, and flow rate of these water tanks gradually decrease. Similarly, during the Steyrmore air-cooling line controlled cooling process, multiple fans are divided into multiple groups, and along the Steyrmore air-cooling line, the opening degree of these fans gradually decreases. The chemical composition of the hot-rolled wire rod for high-strength steel wire rope, by weight percentage, is as follows: C: 0.60%–0.70%, Si: 0.40%–0.80%, Mn: 0.30%–0.60%, P≤0.015%, S≤0.010%, Cr: 0.10%–0.30%; the remainder is Fe and unavoidable impurities. The billet is heated by a heating furnace, the temperature range of the soaking zone of the heating furnace is 1000~1050℃, and the heating time is t=(0.8~1.2)H, where H is the thickness of the billet; During the rolling process, the opening degree of water tank #1 is 20-30%, the outlet water pressure is 3-4 bar, and the flow rate is 20-30 m³ / h. 3 / h, the opening degree of water tank #2 is 15~25%, the outlet water pressure is 2.5~3.5 bar, and the flow rate is 15~25 m³ / h. 3 / h, the opening degree of water tank #3 is 15~25%, the outlet water pressure is 2.5~3.5 bar, and the flow rate is 15~25 m³ / h. 3 / h, the opening degree of water tank #4 is 15~25%, the outlet water pressure is 1.5~2.5 bar, and the flow rate is 15~20 m³ / h. 3 / h, No. 5 water tank opening degree ≤10%, outlet water pressure ≤1.5 bar, flow rate ≤10 m³ / h 3 / h, the temperature before spinning is 850~885℃; The coiled wire after spinning is cooled in a controlled manner on the Stellmore air-cooling line. The initial speed of the roller conveyor is 0.6~0.7m / s, and the speed of the roller conveyor from the 2nd to the 13th section is increased by 0.01~0.03m / s in each section. In the Stellmore air-cooling line, the opening degree of fans 1# to 5# is 95~100%, the opening degree of fan 6# is 75~85%, the opening degree of fan 7# is 65~75%, the opening degree of fan 8# is 55~65%, the insulation cover is fully opened, and the opening angle of the Jialing device is 3~8°. When the temperature is rapidly cooled to 600~630℃, the fans and insulation cover are turned off, and the cooling is carried out slowly at a cooling rate of ≤3℃ / s, with the winding temperature ≤450℃.

2. The method for preparing hot-rolled wire rod for high-strength steel wire rope according to claim 1, characterized in that, During the continuous casting process, the ladle superheats the molten steel to 10–25°C, and the casting is carried out at a constant rate. The carbon segregation at the center of the billet is 0.98–1.

06.

3. The method for preparing hot-rolled wire rod for high-strength steel wire rope according to claim 1, characterized in that, After being heated in the furnace, the billet is descaled by high-pressure water and then rolled into wire rod at a high-speed wire rod with an initial rolling temperature of 920-980℃. The rolling process is controlled by cooling water.

4. A hot-rolled wire rod for high-strength steel wire rope, characterized in that, It is prepared by the method described in any one of claims 1-3 above.

5. The hot-rolled wire rod for high-strength steel wire rope according to claim 4, characterized in that, The hot-rolled wire rod for high-strength steel wire rope has a tensile strength ≥1200MPa, elongation after fracture ≥15%, reduction of area ≥45%, and a microstructure of pearlite + trace ferrite with a sorbite content ≥85%, and is free of core martensite and grain boundary cementite.

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