Hot-rolled round wire rod for titanium deoxidation nail manufacturing and manufacturing method and device of hot-rolled round wire rod

Abstract

The invention discloses a hot-rolled round wire rod for titanium deoxidation nail making and a manufacturing method and device thereof. The method comprises the following steps: in primary smelting, controlling end point carbon of molten steel to be 0.06-0.10%, P to be less than or equal to 0.020%, S to be less than or equal to 0.015% and the end point temperature to be 1660-1690 DEG C; in the low-cost slag washing and refining process, converter back argon blowing refining treatment is adopted; after converter tapping, molten steel oxygen is removed through titanium alloy, microalloying is carried out to improve the structure and the inclusion form, and the soft argon blowing time is longer than or equal to 8 min; in the continuous casting process, whole-course protection and constant-speed pouring are adopted; in the controlled rolling process, the continuous casting billet is fully heated under the temperature condition of 1050-1110 DEG C, and the air-fuel ratio is controlled to be 0.56-0.58 in the heating process; the heated continuous casting billet is subjected to descaling treatment (the descaling water pressure is not lower than 18 MPa); and the continuous casting blank is sequentially subjected to rough rolling, intermediate rolling and finish rolling. Titanium deoxidation microalloying and controlled rolling are adopted, so that the cold heading machining performance requirement is met; and meanwhile, the smelting cost and the energy consumption index are reduced by reducing the refining procedure of the LF furnace.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical methods, and particularly relates to a hot-rolled round wire rod for titanium deoxidation nail making and a manufacturing method and device thereof. Background Art

[0002] Hot-rolled wire rods are generally used to make standard parts such as screws and pins, which require one or more impact loading at room temperature. In order to save raw materials and reduce costs, the nail-making process improves the tensile strength of the workpiece through cold hardening and improves performance. The wire rod used must have good cold forging performance.

[0003] During the rolling process of hot-rolled titanium deoxidation nail-making wire rods, the phenomenon of incomplete rolling often occurs. The diameter of the billet after rolling does not meet the requirements, and the temperature cannot be accurately controlled within an appropriate range during the rolling process, resulting in poor quality of the hot-rolled titanium deoxidation nail-making wire rods after rolling. In addition, during the rolling process, due to the large extrusion pressure for shaping, the billet or the hot-rolled wire rod is prone to pop out from both sides during the rolling process, causing danger. In addition, the method for preparing titanium deoxidation nails is cumbersome and inconvenient, resulting in poor effect of the prepared products. Therefore, the above problems need to be solved urgently. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a titanium deoxidation hot-rolled round wire rod for nail making which has a reasonable design, stable finished product performance and improved product drawing processing performance in view of the deficiencies in the prior art.

[0005] Another technical problem to be solved by the present invention is to provide a method for manufacturing hot-rolled round wire rods for making titanium deoxidized nails, which has reasonable design, low energy consumption and reduces the subsequent breakage rate of finished products, in view of the shortcomings of the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A hot-rolled round wire rod for titanium deoxidation nail making, characterized in that the chemical composition and mass percentage of the hot-rolled round wire rod are C: 0.17-0.22%, Si: 0.03-0.10%, Mn: 0.70-1.00%, P≤0.020%, S≤0.020%, Ti: 0.005-0.025%, and the balance is Fe and unavoidable impurities.

[0008] The technical problem to be solved by the present invention can also be achieved by the following technical solution: the diameter of the hot-rolled round wire rod is φ5.5-12 mm; the tensile strength of the wire rod is ≤510 MPa, and the surface reduction ratio is ≥60%.

[0009] A method for manufacturing the hot-rolled round wire rod is characterized in that the method sequentially comprises a converter primary refining, a slag washing and refining, a deoxidation treatment, a continuous casting process and a controlled rolling process.

[0010] First, converter refining

[0011] Adopting audio monitoring, flame analysis, bomb measurement and integrated endpoint intelligent control technology, the composition and temperature in the converter are accurately controlled, and the endpoint carbon content of the molten steel is controlled to be 0.06%-0.10%, P≤0.020%, S≤0.015%, and the endpoint temperature is 1660℃-1690℃;

[0012] Second, slag washing and refining

[0013] When 1 / 3 of the steel is tapped, 5-8 kg / ton of steel is added as slag washing material, wherein the slag is mixed with refined slag and special lime in a mass ratio of 2:(1.5-1.8), wherein the refined slag is 3.0-5.0 kg / ton of steel, the special lime is 2.0-3.0 kg / t of steel, and then 1.5-2.0 kg / ton of steel is added as carburizer, 10.0-12.0 kg / ton of steel is added as medium carbon ferromanganese, and 1.0-2.0 kg / ton of steel is added as ferrosilicon alloy in sequence. Argon gas is blown 2-5 minutes before tapping, and the argon blowing flow rate is controlled at 80NL / min-320NL / min. The total argon blowing time is ≥8 minutes, and argon is blown throughout the tapping process;

[0014] Third, deoxidation treatment

[0015] After steel is tapped, 0.5-1.5 kg / t of titanium-iron alloy is added, titanium reacts with oxygen to produce oxides, and double-brick argon blowing refining is used to remove oxide inclusions. Then, argon is blown to keep the slag surface "not exposed". The argon blowing flow rate is controlled at 80 NL / min-130 NL / min. After blowing for 5-10 minutes, the molten steel temperature is 1570℃-1600℃.

[0016] Fourth, continuous casting process

[0017] Use the stopper mechanism to control the middle ladle, seal the long nozzle of the large ladle and the intrusive nozzle of the middle ladle and provide argon blowing protection, implement constant casting speed, control the casting speed at 2.2-2.5m / min, and perform offline pickling inspection on the continuous casting billet;

[0018] Fifth, control the rolling process

[0019] The continuously cast billet is fully heated at a temperature of 1050°C to 1110°C, and the air-fuel ratio is controlled at 0.56 to 0.58 during the heating process; the heated continuously cast billet is descaled, and the descaling water pressure is not less than 18MPa; the continuously cast billet is sequentially subjected to rough rolling, intermediate rolling and finish rolling, wherein the start rolling temperature of the rough rolling is 930°C to 970°C, and the inlet temperature of the finish rolling is 880°C to 930°C, thereby obtaining a hot-rolled titanium deoxidation round wire rod for nail making.

[0020] The technical problem to be solved by the present invention can also be achieved by the following technical solution: in step three, the amount of the titanium-iron alloy is 0.5-0.7 kg / ton of steel.

[0021] A manufacturing device for hot-rolled round wire rods for titanium deoxidation nail making, comprising a first shaping and rolling body, a second shaping and rolling body, a fixed connection support frame and a third shaping and rolling body, wherein the second shaping and rolling body is arranged between the first shaping and rolling body and the third shaping and rolling body, and the fixed connection support frame is evenly fixedly installed between the first shaping and rolling body and the second shaping and rolling body, and between the third shaping and rolling body and the second shaping and rolling body;

[0022] The first shaping rolling body, the second shaping rolling body and the third shaping rolling body have the same structure. The first shaping rolling body, the second shaping rolling body and the third shaping rolling body all include a rolling adjustment device and a temperature control protection part, and the temperature control protection part is arranged on both sides of the rolling adjustment device.

[0023] Specifically, the rolling adjustment device includes a first rolling control part, a first electric push rod and a second rolling control part. The first rolling control part and the second rolling control part are distributed in a mirror-symmetrical manner. The first rolling control part and the second rolling control part have the same structure. The first electric push rod is symmetrically fixed on the upper ends of both sides of the first rolling control part.

[0024] Specifically, the first rolling control unit and the second rolling control unit both include a fixed mounting frame, a second electric push rod, a limit stabilization plate, a movable adjustment plate, a motor, a reset limit seat, a rolling wheel and a driving rod. The limit stabilization plate is fixedly connected to the fixed mounting frame, the second electric push rod is evenly fixedly mounted on the fixed mounting frame, and the telescopic end of the fixed mounting frame is inserted through the limit stabilization plate, the movable adjustment plate is fixedly connected to the telescopic end of the second electric push rod, the rolling wheel is evenly rotatably clamped on the movable adjustment plate, the reset limit seat is fixedly mounted on the movable adjustment plate, the motor is fixedly mounted on the reset limit seat, the driving rod is rotatably clamped on the movable adjustment plate, and the end of the driving rod is fixedly connected between the middle parts of the rolling wheels, and the driving end of the motor is fixedly connected to the middle part of the side end of the rolling wheel located on the outside through the driving rod.

[0025] Specifically, the temperature control protection part includes a movable adjustment frame, an air pump, a conveying connecting pipe, a water tank, a display screen, a temperature sensor and a nozzle. The water tank is fixedly connected to the outer end of the movable adjustment frame, the air pump is fixedly connected to the upper part of the outer end of the movable adjustment frame, and the bottom end of the air pump is connected to the upper end of the water tank, the conveying connecting pipe is fixedly connected to the upper end of the water tank, the display screen is fixedly installed on the outer side of the bottom end of the movable adjustment frame, the temperature sensor is evenly fixedly connected to the inner end of the movable adjustment frame, the nozzle is evenly fixedly arranged on the inner side of the movable adjustment frame, and the nozzle is connected to the water tank through a solenoid valve and a connecting hose.

[0026] Specifically, the upper end of the movable adjustment frame is slidably clamped inside the limit stabilization plate in the first rolling control part, the front end of the first electric push rod is fixedly connected to the upper end of the movable adjustment frame, and the fixed connection support frame is fixedly connected between the limit stabilization plates in the first shaping rolling body, the second shaping rolling body and the third shaping rolling body, and the fixed connection support frame is evenly penetrated with fixing holes.

[0027] Specifically, a barrier guide frame is evenly and fixedly mounted on the inner side end of the movable adjustment frame, and the bottom end of the barrier guide frame is arranged in a hook shape.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] First, the present invention adopts a slag washing refining process, and obtains slag washing material from refined slag and special lime, without going through the LF treatment process, thereby achieving carbon reduction and consumption reduction, and achieving precise composition control;

[0030] Second, in step 3 of the present invention, titanium-iron alloy is added after steel is tapped to replace the conventional pure aluminum or aluminum alloy deoxidation, titanium element is reacted with oxygen to produce oxides, and double-brick argon blowing refining is used to remove oxide inclusions, and the deoxidation alloying effect is met by reasonably controlling the argon flow rate, titanium microalloying is used to improve the structure and inclusion morphology, and by controlling rolling, the pinning effect of titanium at the high temperature stage is utilized to improve the residual inclusions in the steel, uniform structure, and good cold heading effect;

[0031] Third, the invention protects the continuous casting process from secondary oxidation, and casts at a constant pulling speed, so that the billet has high purity and excellent internal quality. In addition, the invention adopts audio monitoring, flame analysis, and bomb measurement integrated endpoint intelligent control process technology to prevent slag from tapping, ensuring that the finished product composition meets the high plasticity requirements of cold heading steel.

[0032] The titanium deoxidation wire rod for nail making prepared by the method of the present invention has high plasticity, toughness, good welding performance and cold heading performance. On the premise of meeting the production rhythm and product quality, the cold heading processing performance requirements are met by adopting titanium deoxidation microalloying and controlled rolling; at the same time, the smelting cost and energy consumption indicators are reduced by reducing the refining process of the LF furnace.

[0033] By setting the first shaping and rolling body, the second shaping and rolling body and the third shaping and rolling body, the prepared billet can be rolled continuously and stably, so that the billet can achieve initial, intermediate and final pressing, so that the billet can be finally accurately rolled into a specified diameter. By setting the temperature control and protection part, the temperature can be detected and controlled in real time during the rolling process, so that the rolling temperature is controlled within an appropriate range, and in the rolling process, the billet or hot-rolled round wire rod that pops out will be blocked and fall to the bottom of the blocking guide frame for collection, which plays a role of safety protection. Starting the first electric push rod can move the movable adjustment frame, so that the billet or hot-rolled round wire rod collected inside the bottom of the blocking guide frame can be easily cleaned. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the main structure of the present invention;

[0035] Figure 2 It is a three-dimensional side view of the main body of the present invention;

[0036] Figure 3 A three-dimensional diagram of a first shaping and rolling body of the present invention;

[0037] Figure 4 A three-dimensional diagram of the rolling adjustment device of the present invention;

[0038] Figure 5 is a three-dimensional diagram of the second rolling control unit of the present invention;

[0039] Figure 6 It is a three-dimensional diagram of the temperature control protection part of the present invention;

[0040] Figure 7 It is a side perspective view of the temperature control protection part of the present invention.

[0041] In the figure: 1-first shaping and rolling body; 2-second shaping and rolling body; 3-fixed connection support frame; 4-third shaping and rolling body; 5-rolling adjustment device; 6-temperature control protection part; 7-first rolling control part; 8-first electric push rod; 9-second rolling control part; 10-fixed installation frame; 11-second electric push rod; 12-limiting stabilizing plate; 13-moving adjustment plate; 14-motor; 15-reset limiting seat; 16-rolling wheel; 17-driving rod; 18-moving adjustment frame; 19-air pump; 20-transportation connecting pipe; 21-water storage tank; 22-display screen; 23-temperature sensor; 24-nozzle; 25-blocking guide frame. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0043] A hot-rolled round wire rod for titanium deoxidation nail making, the chemical composition and mass percentage of the hot-rolled round wire rod are: C: 0.17-0.22%, Si: 0.03-0.10%, Mn: 0.70-1.00%, P≤0.020%, S≤0.020%, Ti: 0.005-0.025%, the remainder is Fe and unavoidable impurities, the diameter of the hot-rolled round wire rod is φ5.5-12mm; the tensile strength of the wire rod is ≤510MPa, and the area reduction rate is ≥60%.

[0044] A method for manufacturing the hot-rolled round wire rod, the method sequentially comprises converter primary refining, slag washing and refining, deoxidation treatment, continuous casting process and controlled rolling process,

[0045] First, converter refining

[0046] Adopting audio monitoring, flame analysis, bomb measurement and integrated endpoint intelligent control technology, the composition and temperature in the converter are accurately controlled, and the endpoint carbon content of the molten steel is controlled to be 0.06%-0.10%, P≤0.020%, S≤0.015%, and the endpoint temperature is 1660℃-1690℃;

[0047] Second, slag washing and refining

[0048] When 1 / 3 of the steel is tapped, 5-8 kg / ton of steel is added as slag washing material, wherein the slag is mixed with refined slag and special lime in a mass ratio of 2:(1.5-1.8), wherein the refined slag is 3.0-5.0 kg / ton of steel, the special lime is 2.0-3.0 kg / t of steel, and then 1.5-2.0 kg / ton of steel is added as carburizer, 10.0-12.0 kg / ton of steel is added as medium carbon ferromanganese, and 1.0-2.0 kg / ton of steel is added as ferrosilicon alloy in sequence. Argon gas is blown 2-5 minutes before tapping, and the argon blowing flow rate is controlled at 80NL / min-320NL / min. The total argon blowing time is ≥8 minutes, and argon is blown throughout the tapping process;

[0049] Third, deoxidation treatment

[0050] After steel is tapped, 0.5-1.5 kg / t of titanium-iron alloy is added, titanium reacts with oxygen to produce oxides, and double-brick argon blowing refining is used to remove oxide inclusions. Then, argon is blown to keep the slag surface "not exposed". The argon blowing flow rate is controlled at 80 NL / min-130 NL / min. After blowing for 5-10 minutes, the molten steel temperature is 1570℃-1600℃.

[0051] Fourth, continuous casting process

[0052] Use the stopper mechanism to control the middle ladle, seal the long nozzle of the large ladle and the intrusive nozzle of the middle ladle and provide argon blowing protection, implement constant casting speed, control the casting speed at 2.2-2.5m / min, and perform offline pickling inspection on the continuous casting billet;

[0053] Fifth, control the rolling process

[0054] The continuous casting billet is fully heated at a temperature of 1050°C to 1110°C, and the air-fuel ratio is controlled to be 0.56 to 0.58 during the heating process; the heated continuous casting billet is descaled, and the descaling water pressure is not less than 18MPa; the continuous casting billet is subjected to rough rolling, intermediate rolling and finish rolling in sequence, wherein the start rolling temperature of the rough rolling is 930°C to 970°C, and the inlet temperature of the finish rolling is 880°C to 930°C, thereby obtaining a hot-rolled round wire rod for titanium deoxidation nail making. The rolling process utilizes the pinning effect of TiN formed by titanium at a high temperature stage to prevent the growth of austenite grains, refine the structure of steel, and improve the plasticity of steel; at the same time, the micro-titanium treatment is combined with appropriate post-rolling online heat treatment to improve the residual inclusions in the steel, refine the grains, increase the grain size, and obtain uniform ferrite and pearlite structures.

[0055] In addition, in step one of the present invention, the converter slag audio monitoring process is that the converter audio monitoring system collects the slag noise audio signal at the furnace mouth, and then performs PCM sampling on the analog audio signal to form a digital audio signal; by analyzing the sound signal inside the converter, it is used to monitor the slag position when the foaming in the converter is severe, so as to predict and avoid potential operational risks, such as slag overflow and splashing.

[0056] In step one, the converter flame analysis process is to use intelligent visual recognition technology to convert the furnace mouth slagging and flame combustion signals into digital signals, identify the furnace mouth slagging, smelting splashing, decarbonization combustion conditions, and realize dynamic process control and auxiliary endpoint judgment; use a micro-spectrometer that collects visible light and near-infrared bands as a key component to build a furnace mouth flame radiation information collection system to achieve real-time and effective collection of furnace mouth flame radiation information at the converter steelmaking site; use colorimetric temperature measurement to determine the furnace mouth flame temperature, and combine flame image characteristics and spectral characteristics to establish a steelmaking endpoint temperature prediction model.

[0057] The converter endpoint bombing process described in step 1 is that at the end of blowing or the direct end, when the molten steel in the furnace needs to be tested, the high-temperature detection warhead is automatically dropped into the molten steel in the furnace without stopping the blowing of the furnace, and the detected molten steel temperature, carbon content, and oxygen content are displayed on the screen within 15 seconds to guide the steelmaking operation;

[0058] By integrating audio slag monitoring, flame analysis, and end-point bombing technology, and adopting an artificial intelligence static and dynamic control model with self-learning function, decarburization and temperature changes in the molten pool can be predicted in real time, the carbon temperature hit rate can be improved, and the problem of transparency of complex furnace conditions during the converter blowing process can be solved, providing data support for the realization of intelligent converter steelmaking.

[0059] Embodiment 1, a method for manufacturing a hot-rolled titanium deoxidized round wire rod for nail making, the method comprising the following steps:

[0060] Converter smelting: final composition [C] 0.07%, [P] 0.012%, [S] 0.013%, oxygen content in converter final steel 422ppm, final temperature 1670℃; tapping time 4.5min; slag washing material, carburizer, medium carbon ferromanganese and ferrosilicon alloy are added in sequence when 1 / 3 of the steel is tapped, including 4.0kg / t steel of refined slag, 3.0kg / ton steel of lime and 1.6kg / ton steel of carburizer; slag stopper is used for slag blocking operation, and the slag discharge amount is 0.3kg / ton steel; argon blowing starts 3min before tapping.

[0061] Post-furnace deoxidation and refining: After steel is tapped, the argon blowing flow rate is controlled at 300NL / min. After blowing for 2 minutes, the temperature is measured and steel samples are taken. 0.7kg / ton of titanium iron is added for deoxidation. Then, the slag surface is kept "not exposed" and cleanly blown. The argon blowing flow rate is controlled at 100NL / min. After blowing for 8 minutes, the molten steel temperature is 1600℃.

[0062] Continuous casting: Protective pouring throughout the whole process, long water nozzle is used from ladle to tundish and argon seal protection is carried out, and the tundish cover is tightly sealed; argon is used to drive and replace the air in the tundish 2 minutes before pouring; low-carbon and low-silicon covering agent is used for the molten steel surface in the tundish, and ordinary carbon alkaline covering agent is added to the upper layer, and black surface operation is maintained throughout the whole process; after pouring, the tundish liquid level is maintained at 700mm, and the crystallizer uses special protective slag for medium carbon steel, and the pulling speed is 2.2m / min.

[0063] Steel rolling: heating furnace temperature 1010°C; descaling treatment (descaling water pressure 20MPa) is performed on the heated continuous casting billet; rough rolling (starting rolling temperature 950°C), intermediate rolling and finishing rolling (finishing rolling entrance 880°C) are performed on the continuous casting billet in sequence; all the insulation covers of the air cooling line are closed, and the roller speed is 280mm / s, thereby obtaining titanium deoxidation wire rod for nail making.

[0064] The chemical composition and mechanical properties of the titanium deoxidized wire rod for nail making prepared by the method described in Example 1 are shown in Table 1. In Table 1, the balance of the chemical composition is Fe and unavoidable impurities.

[0065] Table 1

[0066]

[0067] Embodiment 2, a method for manufacturing a hot-rolled titanium deoxidized wire rod for nail making, the method comprising the following steps:

[0068] Converter smelting: final composition [C] 0.05%, [P] 0.010%, [S] 0.014%, oxygen content in converter final steel 632ppm, final temperature 1682℃; tapping time 4.5min; slag washing material, carburizer, medium carbon ferromanganese and ferrosilicon alloy are added in sequence when 1 / 3 of the steel is tapped, of which carburizer is 1.8kg / t steel, refined slag is 4.2kg / t steel, and lime is 3.0kg / t steel; slag stopper is used for slag blocking operation, and the slag discharge amount is 0.3kg / t steel; argon blowing starts 3min before tapping.

[0069] Post-furnace deoxidation and refining: After steel is tapped, the argon blowing flow rate is controlled at 300NL / min. After blowing for 2 minutes, the temperature is measured and steel samples are taken. 0.6kg / ton of titanium iron is added for deoxidation. Then, the slag surface is kept "not exposed" and cleanly blown. The argon blowing flow rate is controlled at 100NL / min. After blowing for 8 minutes, the molten steel temperature is 1585℃.

[0070] Continuous casting: Protective pouring throughout the whole process, long water nozzle is used from ladle to tundish and argon seal protection is carried out, and the tundish cover is tightly sealed; 2 minutes before pouring, argon is used to drive out the air in the tundish; low-carbon and low-silicon covering agent is used for the molten steel surface in the tundish, and ordinary carbon alkaline covering agent is added to the upper layer, and black surface operation is maintained throughout the whole process; after pouring, the tundish liquid level is maintained at 700mm, and the crystallizer uses special protective slag for medium carbon steel, and the pulling speed is 2.3-2.4m / min.

[0071] Steel rolling: heating furnace temperature is 1090°C; the heated continuous casting billet is descaled (descaling water pressure is 20MPa); the continuous casting billet is subjected to rough rolling (starting rolling temperature is 970°C), intermediate rolling and finishing rolling (finishing rolling entrance is 910°C) in sequence; the air cooling line insulation covers are all closed, and the roller speed is 280mm / s.

[0072] The chemical composition and mechanical properties of the titanium deoxidized wire rod for nail making prepared by the method described in Example 2 are shown in Table 2. In Table 2, the balance of the chemical composition is Fe and unavoidable impurities.

[0073] Table 2

[0074]

[0075] Embodiment 3, a method for manufacturing a hot-rolled round wire rod for titanium deoxidation nail making, the method comprising the following steps:

[0076] Converter smelting: final composition [C] 0.08%, [P] 0.012%, [S] 0.016%, oxygen content in converter final steel 462ppm, final temperature 1675℃; tapping time 4.5min; slag washing material, carburizer, medium carbon ferromanganese and ferrosilicon alloy are added in sequence when 1 / 3 of the steel is tapped, of which carburizer is 1.6kg / t steel, slag washing material is 4.0kg / t steel, and lime is 3.0kg / t steel; slag blocking operation is carried out using slag blocking plugs, and the slag discharge amount is 0.3kg / ton steel; argon blowing is started 3min before tapping.

[0077] Post-furnace deoxidation and refining: After steel is tapped, the argon blowing flow rate is controlled at 300NL / min. After blowing for 2 minutes, the temperature is measured and steel samples are taken. 0.8kg / ton of titanium iron is added for deoxidation, and then the slag surface is kept "not exposed" and cleanly blown. The argon blowing flow rate is controlled at 100NL / min. After blowing for 12 minutes, the molten steel temperature is 1588℃.

[0078] Continuous casting: Protective pouring throughout the whole process, long water nozzle is used from ladle to tundish and argon seal protection is carried out, and the tundish cover is tightly sealed; low-carbon and low-silicon covering agent is used for the molten steel surface in the tundish, and general carbon alkaline covering agent is added to the upper layer, and black surface operation is maintained throughout the whole process; after pouring, the tundish liquid level is maintained at 700mm, and the crystallizer uses special protective slag for medium carbon steel, and the pulling speed is 2.1-2.2m / min.

[0079] Steel rolling: heating furnace temperature 1105°C; descaling the heated continuous casting billet (descaling water pressure 20MPa); rough rolling (starting rolling temperature 970°C), intermediate rolling and finishing rolling (finishing rolling entrance 880°C) are carried out on the continuous casting billet in sequence; all the insulation covers of the air cooling line are closed, and the roller speed is 280mm / s.

[0080] The chemical composition and mechanical properties of the titanium deoxidized wire rod for nail making prepared by the method described in Example 3 are shown in Table 3. In Table 3, the balance of the chemical composition is Fe and unavoidable impurities.

[0081] Table 3

[0082]

[0083] Embodiment 4, a method for manufacturing a hot-rolled round wire rod for making titanium deoxidation nails, the method comprising the following steps:

[0084] Converter smelting: final composition [C] 0.08%, [P] 0.020%, [S] 0.009%, oxygen content in converter final steel 389ppm, final temperature 1675℃; tapping time 4.0min; slag washing material, carburizer, medium carbon ferromanganese and ferrosilicon alloy are added in sequence when 1 / 3 of the steel is tapped, including 4.0kg / t steel of refined slag, 3.0kg / ton steel of lime and 1.9kg / ton steel of carburizer; slag stopper is used for slag blocking operation, and the slag discharge amount is 0.3kg / ton steel; argon blowing starts 3min before tapping.

[0085] Post-furnace deoxidation and refining: After steel is tapped, the argon blowing flow rate is controlled at 300NL / min. After blowing for 2 minutes, the temperature is measured and steel samples are taken. 0.5kg / ton of titanium iron is added for deoxidation. Then, the slag surface is kept "not exposed" and cleanly blown. The argon blowing flow rate is controlled at 100NL / min. After blowing for 8 minutes, the molten steel temperature is 1600℃.

[0086] Continuous casting: Protective pouring throughout the whole process, long water nozzle is used from ladle to tundish and argon seal protection is carried out, and the tundish cover is tightly sealed; 2 minutes before pouring, argon is used to drive out the air in the tundish; low-carbon and low-silicon covering agent is used for the molten steel surface in the tundish, and ordinary carbon alkaline covering agent is added to the upper layer, and black surface operation is maintained throughout the whole process; after pouring, the tundish liquid level is maintained at 700mm, and the crystallizer uses special protective slag for medium carbon steel, and the pulling speed is 2.4m / min.

[0087] Steel rolling: heating furnace temperature 1110°C; descaling treatment (descaling water pressure 20MPa) is performed on the heated continuous casting billet; rough rolling (starting rolling temperature 960°C), intermediate rolling and finishing rolling (finishing rolling entrance 890°C) are performed on the continuous casting billet in sequence; all the insulation covers of the air cooling line are closed, and the roller speed is 280mm / s, thereby obtaining titanium deoxidation wire rod for nail making.

[0088] The chemical composition and mechanical properties of the titanium deoxidized wire rod for nail making prepared by the method described in Example 4 are shown in Table 4. In Table 4, the balance of the chemical composition is Fe and unavoidable impurities.

[0089] Table 4

[0090]

[0091] Embodiment 5, a method for manufacturing a hot-rolled round wire rod for making titanium deoxidation nails, the method comprising the following steps:

[0092] Converter smelting: final composition [C] 0.10%, [P] 0.013%, [S] 0.012%, oxygen content in converter final steel 362ppm, final temperature 1673℃; tapping time 4.0min; slag washing material, carburizer, medium carbon ferromanganese and ferrosilicon alloy are added in sequence when 1 / 3 of the steel is tapped, including 4.0kg / t steel of refined slag, 3.0kg / ton steel of lime and 1.5kg / ton steel of carburizer; slag stopper is used for slag blocking operation, and the slag amount is 0.3kg / ton steel; argon blowing starts 3min before tapping.

[0093] Post-furnace deoxidation and refining: After steel is tapped, the argon blowing flow rate is controlled at 300NL / min. After blowing for 2 minutes, the temperature is measured and steel samples are taken. 1.5kg / ton of titanium iron is added for deoxidation. Then, the slag surface is kept "not exposed" and cleanly blown. The argon blowing flow rate is controlled at 100NL / min. After blowing for 8 minutes, the molten steel temperature is 1600℃.

[0094] Continuous casting: Protective pouring throughout the whole process, long water nozzle is used from ladle to tundish and argon seal protection is carried out, and the tundish cover is tightly sealed; 2 minutes before pouring, argon is used to drive out the air in the tundish; low-carbon and low-silicon covering agent is used for the molten steel surface in the tundish, and ordinary carbon alkaline covering agent is added to the upper layer, and black surface operation is maintained throughout the whole process; after pouring, the tundish liquid level is maintained at 700mm, and the crystallizer uses special protective slag for medium carbon steel, and the pulling speed is 2.4m / min.

[0095] Steel rolling: heating furnace temperature 1100°C; descaling treatment (descaling water pressure 20MPa) is performed on the heated continuous casting billet; rough rolling (starting rolling temperature 960°C), intermediate rolling and finishing rolling (finishing rolling entrance 900°C) are performed on the continuous casting billet in sequence; all the insulation covers of the air cooling line are closed, and the roller speed is 280mm / s, thereby obtaining titanium deoxidation wire rod for nail making.

[0096] The chemical composition and mechanical properties of the titanium deoxidized wire rod for nail making prepared by the method described in Example 5 are shown in Table 5. In Table 5, the balance of the chemical composition is Fe and unavoidable impurities.

[0097] Table 5

[0098]

[0099] In Comparative Example 1, the conventional aluminum deoxidation process was used to produce the wire rod for nail making.

[0100] In Comparative Example 2, the conventional LF refining process was used to produce wire rod for nail making.

[0101] In comparative example 3, the wire rod for nail making is produced by adopting the existing conventional aluminum deoxidation process and LF refining treatment process.

[0102] The wire rods produced by the methods described in Examples 1-3 and Comparative Examples 1-3 were subjected to performance testing and application statistics, including tensile properties, cold heading pass rate, metallographic structure and customer processing defect statistics, wherein 5-10 sections of the wire rods produced in each example were taken for the above-mentioned tests.

[0103]

[0104]

[0105] From the above, it can be seen that the method described in the present invention adopts "titanium deoxidation + slag washing and refining". The titanium deoxidation wire rod for nail making obtained by this method will not produce floccules during the casting process, which effectively ensures the stability of product quality. Moreover, the titanium deoxidation wire rod for nail making obtained by this method has low carbon content, good tensile strength, low energy consumption, low cracking defective rate, and good customer response.

[0106] Example 6

[0107] like Figure 1-7 As shown, a manufacturing device for hot-rolled round wire rods for titanium deoxidation nail making comprises a first shaping and rolling body 1, a second shaping and rolling body 2, a fixed connection support frame 3 and a third shaping and rolling body 4, wherein the second shaping and rolling body 2 is arranged between the first shaping and rolling body 1 and the third shaping and rolling body 4, and the fixed connection support frame 3 is evenly fixedly installed between the first shaping and rolling body 1 and the second shaping and rolling body 2 and between the third shaping and rolling body 4 and the second shaping and rolling body 2, and after the fixed connection support frame 3 is connected to an external support frame and other erection equipment, the device can be erected and fixed for use;

[0108] The first shaping rolling body 1, the second shaping rolling body 2 and the third shaping rolling body 4 have the same structure. The first shaping rolling body 1, the second shaping rolling body 2 and the third shaping rolling body 4 all include a rolling adjustment device 5 and a temperature control protection part 6. The temperature control protection part 6 is arranged on both sides of the rolling adjustment device 5. The rolling adjustment device 5 includes a first rolling control part 7, a first electric push rod 8 and a second rolling control part 9. The first rolling control part 7 and the second rolling control part 9 are mirror-symmetrically distributed. The first rolling control part 7 and the second rolling control part 9 have the same structure. The first electric push rod 8 is symmetrically fixedly installed on the upper ends of both sides of the first rolling control part 7. The first rolling control part 7 and the second rolling control part 9 both include a fixed installation frame 10, a second electric push rod 11, a limit stabilization plate 12, a movable adjustment plate 13, a motor 14, a reset limit seat 15, a rolling wheel 16 and a driving rod 17. The limit stabilization plate 12 is fixedly connected to the fixed installation frame 10, and the second electric push rod 11 is evenly fixedly installed on the fixed The movable adjustment plate 13 is fixedly connected to the telescopic end of the second electric push rod 11, and the rolling wheel 16 is evenly rotated and clamped on the movable adjustment plate 13. The reset limit seat 15 is fixedly installed on the movable adjustment plate 13, and the motor 14 is fixedly installed on the reset limit seat 15. The driving rod 17 is rotatably clamped on the movable adjustment plate 13, and the end of the driving rod 17 is fixedly connected between the middle parts of the rolling wheels 16. The driving end of the motor 14 is fixedly connected to the middle part of the side end of the rolling wheel 16 located on the outside through the driving rod 17. The movable adjustment plate 13 can be driven to move by the second electric push rod 11, and the symmetrically arranged rolling wheels 16 are squeezed close to each other, and the motor 14 is started. The motor 14 can drive each rolling wheel 16 to rotate, so that the rolling wheels 16 that squeeze each other and rotate can complete the rolling of the billet conveyed by the middle part, so that the billet is fully extruded and shaped.

[0109] The temperature control protection part 6 includes a mobile adjustment frame 18, an air pump 19, a delivery connection pipe 20, a water tank 21, a display screen 22, a temperature sensor 23 and a nozzle 24. The water tank 21 is fixedly connected to the outer end of the mobile adjustment frame 18, the air pump 19 is fixedly connected to the upper part of the outer end of the mobile adjustment frame 18, and the bottom end of the air pump 19 is connected to the upper end of the water tank 21, the delivery connection pipe 20 is fixedly connected to the upper end of the water tank 21, the display screen 22 is fixedly installed on the outer side of the bottom end of the mobile adjustment frame 18, and the temperature sensor 23 is evenly fixedly connected to the outer end of the water tank 21. At the inner end of the movable adjusting frame 18, the nozzle 24 is evenly fixedly arranged on the inner side of the movable adjusting frame 18, and the nozzle 24 is connected to the water tank 21 through the solenoid valve and the connecting hose. The evenly distributed temperature sensor 23 can detect and monitor the temperature during the rolling process, and display the temperature on the display screen 22. When the temperature is too high, the air pump 19 automatically runs, and the solenoid valve and other valve bodies arranged on the inner side of the water tank 21 automatically open, so that the cooling liquid stored in the water tank 21 is sprayed out from each nozzle 24, thereby realizing automatic cooling.

[0110] The upper end of the movable and adjusting frame 18 is slidably engaged with the limit stabilizing plate 12 in the first rolling control part 7, and the front end of the first electric push rod 8 is fixedly connected to the upper end of the movable and adjusting frame 18. The fixed connection support frame 3 is fixedly connected between the limit stabilizing plates 12 in the first shaping and rolling body 1, the second shaping and rolling body 2 and the third shaping and rolling body 4. Fixed holes are evenly penetrated on the fixed connection support frame 3. The inner side end of the movable and adjusting frame 18 is evenly fixedly installed with a blocking guide frame 25. The bottom end of the blocking guide frame 25 is arranged in a hook shape. During the rolling process, the popped-out billet or hot-rolled round wire rod is blocked and falls to the bottom end of the blocking guide frame 25 for collection, which plays a role of safety protection. Starting the first electric push rod 8 can move the movable and adjusting frame 18, so that the billet or hot-rolled round wire rod collected inside the bottom end of the blocking guide frame 25 can be easily cleaned.

[0111] During use, the billet can be continuously rolled by the first shaping rolling body 1, the second shaping rolling body 2 and the third shaping rolling body 4, so that the billet can achieve initial pressure, intermediate pressure and final pressure, so that the billet can be accurately rolled into a specified diameter. During the rolling process, the billet first enters between the symmetrically arranged rolling wheels 16 in the first shaping rolling body 1, and the second electric push rod 11 in the first rolling control part 7 and the second rolling control part 9 is started. The second electric push rod 11 can drive the movable adjustment plate 13 to move, and the symmetrically arranged rolling wheels 16 are squeezed close to each other, and the motor 14 is started. The motor 14 can drive each rolling wheel 16 to rotate, so that the rolling wheels 16 that squeeze and rotate each other can complete the rolling of the billet conveyed from the middle, so that the billet is fully extruded and shaped, and is continuously rolled by the first shaping rolling body 1, the second shaping rolling body 2 and the third shaping rolling body 4, so that the billet can be accurately rolled into a hot-rolled round wire rod with a specified diameter;

[0112] During the rolling process, the temperature of the rolling process can be controlled and adjusted by the temperature control protection part 6 arranged on both sides of the first shaping rolling body 1, the second shaping rolling body 2 and the third shaping rolling body 4. The temperature during the rolling process can be detected and monitored by the evenly distributed temperature sensors 23, and the temperature is displayed on the display screen 22. When the temperature is too high, the air pump 19 automatically runs, and the solenoid valve and other valve bodies arranged on the inner side of the water storage tank 21 automatically open, so that the cooling liquid stored in the water storage tank 21 is sprayed out from each nozzle 24, so as to realize automatic cooling, and the rolling process can be controlled within a suitable range. In addition, by moving the uniform baffle guide rack 25 inside the adjusting frame 18, the popped-out billet or hot-rolled round wire rod is baffled and falls on the bottom end of the baffle guide rack 25 for collection during the rolling process, so as to play a role of safety protection. Starting the first electric push rod 8 can move the adjusting frame 18, so that the billet or hot-rolled round wire rod collected inside the bottom end of the baffle guide rack 25 can be easily cleaned.

[0113] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. Titanium deoxidation hot-rolled round wire rod for nail making, characterized in that: The chemical composition and mass percentage of the hot-rolled round wire rod are: C: 0.17-0.22%, Si: 0.03-0.10%, Mn: 0.70-1.00%, P≤0.020%, S≤0.020%, Ti: 0.005-0.025%, and the remainder is Fe and unavoidable impurities.

2. The hot-rolled titanium deoxidized wire rod for nail making according to claim 1, characterized in that: The diameter of the hot-rolled round wire rod is φ5.5-12 mm; the tensile strength of the wire rod is ≤510 MPa, and the surface reduction rate is ≥60%.

3. A method for manufacturing a hot-rolled titanium deoxidized round wire rod for nail making according to claim 1 or 2, characterized in that: The method includes converter primary refining, slag washing and refining, deoxidation treatment, continuous casting and controlled rolling. First, converter refining The endpoint intelligent control process integrating audio monitoring, flame analysis and bomb measurement is adopted to accurately control the composition and temperature in the converter furnace, control the endpoint carbon content of the molten steel to 0.06%-0.10%, P≤0.020%, S≤0.015%, and the endpoint temperature to 1660℃-1690℃; Second, slag washing and refining When 1 / 3 of the steel is tapped, add 5-8kg / ton of steel slag washing material, the slag is mixed with refined slag and special lime in a mass ratio of 2: (1.5-1.8), wherein the refined slag is 3.0-5.0kg / t steel, the special lime is 2.0-3.0kg / t steel, and then add recarburizer 1.5-2.0kg / ton steel, medium carbon ferromanganese 10.0-12.0kg / ton steel, ferrosilicon alloy 1.0-2.0kg / ton steel in sequence, start blowing argon 2-5min before tapping, the argon blowing flow rate is controlled at 80NL / min-320NL / min, the total argon blowing time is ≥8min, and argon is blown throughout the tapping process; Third, deoxidation treatment After steel is tapped, 0.5-1.5 kg / t of titanium-iron alloy is added, titanium reacts with oxygen to produce oxides, and double-brick argon blowing refining is used to remove oxide inclusions. Then, argon is blown to keep the slag surface "not exposed". The argon blowing flow rate is controlled at 80NL / min-130NL / min. After blowing for 5min-10min, the molten steel temperature is 1570℃-1600℃. Fourth, continuous casting process Use the stopper mechanism to control the middle ladle, seal the long nozzle of the large ladle and the intrusive nozzle of the middle ladle and provide argon blowing protection, implement constant casting speed, control the casting speed at 2.2-2.5m / min, and perform offline pickling inspection on the continuous casting billet; Fifth, control the rolling process The continuously cast billet is fully heated at a temperature of 1050°C to 1110°C, and the air-fuel ratio is controlled at 0.56 to 0.58 during the heating process; the heated continuously cast billet is descaled, and the descaling water pressure is not less than 18MPa; the continuously cast billet is subjected to rough rolling, intermediate rolling and finish rolling in sequence, wherein the start rolling temperature of the rough rolling is 930°C to 970°C, and the inlet temperature of the finish rolling is 880°C to 930°C, thereby obtaining a hot-rolled round wire rod for titanium deoxidation nail making.

4. The method for manufacturing a hot-rolled titanium deoxidized round wire rod for nail making according to claim 3, characterized in that: In step 3, the amount of the titanium-iron alloy used is 0.5-0.7 kg / ton of steel.

5. A manufacturing device for hot-rolled titanium deoxidized wire rod for nail making according to claim 1 or 2, characterized in that: The invention comprises a first shaping rolling body (1), a second shaping rolling body (2), a fixed connection support frame (3) and a third shaping rolling body (4), wherein the second shaping rolling body (2) is arranged between the first shaping rolling body (1) and the third shaping rolling body (4), and the fixed connection support frame (3) is evenly fixedly installed between the first shaping rolling body (1) and the second shaping rolling body (2) and between the third shaping rolling body (4) and the second shaping rolling body (2); The first shaping rolling body (1), the second shaping rolling body (2) and the third shaping rolling body (4) have the same structure, and the first shaping rolling body (1), the second shaping rolling body (2) and the third shaping rolling body (4) all comprise a rolling adjustment device (5) and a temperature control protection part (6), and the temperature control protection part (6) is arranged on both sides of the rolling adjustment device (5).

6. The manufacturing device for hot-rolled titanium deoxidized round wire rod for nail making according to claim 5, characterized in that: The rolling adjustment device (5) comprises a first rolling control part (7), a first electric push rod (8) and a second rolling control part (9); the first rolling control part (7) and the second rolling control part (9) are distributed in a mirror-symmetrical manner; the first rolling control part (7) and the second rolling control part (9) have the same structure; and the first electric push rod (8) is symmetrically fixedly mounted on the upper ends of both sides of the first rolling control part (7).

7. The manufacturing device for hot-rolled titanium deoxidized wire rod for nail making according to claim 6, characterized in that: The first rolling control unit (7) and the second rolling control unit (9) both comprise a fixed mounting frame (10), a second electric push rod (11), a position limiting stabilization plate (12), a movable adjustment plate (13), a motor (14), a reset position limiting seat (15), a rolling wheel (16) and a driving rod (17); the position limiting stabilization plate (12) is fixedly connected to the fixed mounting frame (10); the second electric push rod (11) is evenly fixedly mounted on the fixed mounting frame (10); the telescopic end of the fixed mounting frame (10) is inserted through the position limiting stabilization plate (12); the movable adjustment plate (13) The rolling wheel (16) is fixedly connected to the telescopic end of the second electric push rod (11), the rolling wheel (16) is evenly rotatably clamped on the movable adjustment plate (13), the reset limit seat (15) is fixedly mounted on the movable adjustment plate (13), the motor (14) is fixedly mounted on the reset limit seat (15), the driving rod (17) is rotatably clamped on the movable adjustment plate (13), and the end of the driving rod (17) is fixedly connected between the middle parts of the rolling wheel (16), and the driving end of the motor (14) is fixedly connected to the middle part of the side end of the rolling wheel (16) located on the outside through the driving rod (17).

8. The manufacturing device for hot-rolled titanium deoxidized round wire rod for nail making according to claim 7, characterized in that: The temperature control protection part (6) comprises a movable adjustment frame (18), an air pump (19), a delivery connection pipe (20), a water storage tank (21), a display screen (22), a temperature sensor (23) and a nozzle (24); the water storage tank (21) is fixedly connected to the outer end of the movable adjustment frame (18); the air pump (19) is fixedly connected to the upper part of the outer end of the movable adjustment frame (18), and the bottom end of the air pump (19) is connected to the upper end of the water storage tank (21); the delivery connection pipe (20) is fixedly connected to the upper end of the water storage tank (21); the display screen (22) is fixedly installed on the outer side of the bottom end of the movable adjustment frame (18); the temperature sensor (23) is evenly fixedly connected to the inner end of the movable adjustment frame (18); the nozzle (24) is evenly fixedly arranged on the inner side of the movable adjustment frame (18), and the nozzle (24) is connected to the water storage tank (21) via a solenoid valve and a connecting hose.

9. The manufacturing device for hot-rolled titanium deoxidized round wire rod for nail making according to claim 8, characterized in that: The upper end of the movable adjustment frame (18) is slidably engaged inside the limit stabilizing plate (12) in the first rolling control part (7), the front end of the first electric push rod (8) is fixedly connected to the upper end of the movable adjustment frame (18), the fixed connection support frame (3) is fixedly connected between the limit stabilizing plates (12) in the first shaping rolling body (1), the second shaping rolling body (2) and the third shaping rolling body (4), and the fixed connection support frame (3) is evenly penetrated with fixing holes.

10. The manufacturing device for hot-rolled titanium deoxidized round wire rod for nail making according to claim 9, characterized in that: The inner side end of the movable adjustment frame (18) is evenly and fixedly mounted with a barrier guide frame (25), and the bottom end of the barrier guide frame (25) is arranged in a hook shape.

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