A method for producing 6.5 gauge wire coil SWRCH22A cold heading steel
Through the 6.5-specification wire disk circle SWRCH22A cold heading steel production method that controls heating temperature, rolling temperature, deformation amount, segmented cooling and alloy element adjustment, the existing problems of low production efficiency, poor quality and high cost are solved, and efficient and low-cost production is achieved, and product performance is improved.
Patent Information
- Application Number
- CN202411962835.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-04-04
AI Technical Summary
The existing SWRCH22A cold heading steel has low production efficiency, poor quality and high cost, and has quality defects such as peeling, bulging, and bubbles. The use of 6000mm short billet rolling leads to an increase in energy consumption.
The 6.5-specification wire disk circular SWRCH22A cold heading steel production method is adopted. By controlling the heating temperature, rolling temperature, deformation amount, and segmented cooling, the plasticity and strength of the finished steel are enhanced, and alloy elements are adjusted to reduce production costs. The specific steps include uniform heating of the continuous casting billet through a three-stage stepping heating furnace, setting water through cooling, and adjusting the structure of the finished steel into ferrite + pearlite.
It significantly improves production efficiency, reduces production costs, improves the plasticity and strength of the product, reduces the consumption of precious metal resources, ensures that the product surface is dense, uniform and smooth, and has better performance than technical standards.
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of iron and steel metallurgy, and in particular to a production method of 6.5 specification wire rod coil SWRCH22A cold heading steel. Background Art
[0002] High-speed wire SWRCH22A cold heading steel is a steel grade produced according to the Japanese standard JIS G3507-1-2021. It is a steel grade for low- and medium-carbon high-quality carbon structural steel and alloy steel wire, with excellent cold processing performance, mechanical properties and surface quality. With the rapid development of industry and manufacturing, the demand for high-quality and high-performance fasteners is increasing. As an important fastener material, SWRCH22A cold heading steel has broad application prospects in the fields of automobiles, mechanical equipment, and electronic products.
[0003] At present, in order to improve the quality of SWRCH22A cold heading steel, a large amount of trace elements are added in the production, which leads to the increase of production cost and the consumption of precious metal resources. At the same time, due to the use of high rolling and high wire drawing temperature, the product surface is prone to peeling, bulging, bubbles and other quality defects; the use of 6000mm short square billet for rolling has low production efficiency and increases the energy consumption in the rolling process.
[0004] Therefore, it is necessary to design a production method for 6.5 specification wire rod coil SWRCH22A cold heading steel to solve the problems of low production efficiency, poor quality and high cost of the existing SWRCH22A cold heading steel. Summary of the invention
[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for producing 6.5 specification wire rod coil SWRCH22A cold heading steel, by controlling the heating temperature, rolling temperature, deformation amount, and segmented cooling to enhance the plasticity and strength of the finished steel, and at the same time adjusting the alloy elements to reduce the production cost.
[0006] The technical solution adopted by the present invention to solve the technical problem is: a method for producing 6.5 specification wire rod round SWRCH22A cold heading steel, comprising the following steps:
[0007] S1. The chemical composition of the steel billet used for continuous casting is C: 0.18-0.20, Si: 0.03-0.05, Mn: 0.7-0.9, Al: 0.025-0.035, S and P impurity elements ≤ 0.015, nitrogen content ≤ 70ppm, and the rest is iron and unavoidable impurities;
[0008] S2, the continuous casting billet is evenly heated in a three-stage walking beam heating furnace;
[0009] S3. The molten steel after being discharged from the heating furnace is subjected to rough rolling, intermediate rolling, pre-finishing rolling, finishing rolling, module mill, and wire laying machine to produce finished coils. Water-penetrating cooling is set before and after finishing rolling and after the module mill to adjust the cooling rate of the steel and control the grain deformation and phase change temperature.
[0010] S4, after the spinning machine, it passes through the Stelmor air cooling line to adjust the internal structure of the finished steel to ferrite + pearlite.
[0011] Specifically, the size of the continuous casting billet in step S1 is 165mm*165mm*12000mm.
[0012] Specifically, the three-stage walking beam heating furnace in step S2 adopts intelligent combustion control technology and sets different temperature range standards according to different steel types and production specifications.
[0013] Specifically, the temperature range standard is that when producing SWRCH22A steel with a specification of φ6.5mm with cold billets, the temperature of the second section of the three-stage walking beam heating furnace is controlled at 890°C, the temperature of the first section is controlled at 1080°C, and the temperature of the equalizing section is controlled at 1120°C. When using cold billets for production, the temperature of each section increases to varying degrees, the starting rolling temperature is controlled at 1010°C, and automatic combustion technology is adopted. The temperature difference of the billet passing rod is controlled within 10°C.
[0014] Specifically, the rough rolling and intermediate rolling areas in step S3 use 14 horizontal and vertical alternating rolling mills, and the pre-finishing rolling area uses 14 horizontal and vertical alternating rolling mills and two Danieli finishing mills, and the material shape is controlled to be a 18.9mm circle; then it is cooled through two water tanks, and the water supply pressure of the water tank is controlled to be above 14Bar to control the cooling rate of the rolled piece, and after passing through the 3# flying shear head, it enters the Danieli finishing mill group, at which time the temperature is controlled to 920±10℃, and the finishing mill group uses a one-to-two 45° top-crossing finishing mill, and uses a roller ring hole type that is universal for all specifications. Different numbers of rolling mills are used according to different production specifications, and the outlet out-of-roundness is controlled within 0.3mm.
[0015] Specifically, the rolled piece is cooled again after the finishing mill, passes through three water tanks, and the temperature of the rolled piece is controlled to 920°C before entering the dual-module unit. After passing through four rolling mills, the required product size is finally achieved. After the finished product is finished, it is evenly cooled in sections through three water tanks, and finally the spinning temperature is also controlled at 920±10°C to ensure that the product surface is dense, uniform and smooth.
[0016] Specifically, a Danieli high-speed flying shear device is installed in front of the spinning machine in step S4 to automatically shear the steel with excessive head and tail dimensions and excessive mechanical properties. After spinning, the steel passes through the Stelmor air cooling line, where an insulation cover is used to slowly cool the finished product and adjust the product structure to ensure that the final product contains pearlite and ferrite without a hardened layer.
[0017] The present invention has the following beneficial effects:
[0018] The 6.5-gauge wire rod coil SWRCH22A cold heading steel production method designed by the present invention significantly reduces the alloy composition and increases the hourly output compared with the hot rolling production mode. Compared with hot rolling production, it can reduce the overall cost by 85 yuan / ton, greatly reducing the production cost.
[0019] The 6.5-gauge wire coil SWRCH22A cold heading steel production method designed by the present invention controls the heating temperature, the rolling temperature, the deformation amount, and the segmented cooling to enhance the plasticity and strength of the finished steel, and adjusts the alloy elements at the same time, thereby reducing the consumption of precious metal resources and lowering the production cost.
[0020] The invention designs a 6.5 specification wire rod coil SWRCH22A cold heading steel production method, a three-stage walking beam heating furnace, and uses pulse combustion technology for automatic combustion to ensure uniform temperature of the steel rod, while increasing the speed of the walking beam, designing a spaced furnace entry process, reducing the furnace time of the steel billet, controlling grain growth, and improving product performance.
[0021] The 6.5-gauge wire rod coil SWRCH22A cold heading steel production method designed by the present invention controls a large reduction in a low-speed zone, so that the grains are severely deformed to improve the final performance of the product; the water tank is modified to increase the nozzle reaction speed, control the cooling rate of the rolled piece, and control the temperature of the rolled piece through process cooling and post-rolling cooling to ensure product performance indicators. DETAILED DESCRIPTION
[0022] The technical solutions in the embodiments of the present invention are described in detail below. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0023] A method for producing 6.5 gauge wire rod coil SWRCH22A cold heading steel comprises the following steps:
[0024] 1. The size of the continuous casting billet is 165mm*165mm*12000mm. The chemical composition weight percentage of the steel billet used for continuous casting billet is C: 0.18~0.20, Si: 0.03~0.05, Mn: 0.7~0.9, Al: 0.025~0.035, S and P impurity elements ≤0.015, no niobium and vanadium precious metal elements are required, nitrogen content ≤70ppm, and the rest is iron and unavoidable impurities.
[0025] 2. The continuous casting billet is evenly heated in a three-stage walking beam heating furnace; the three-stage walking beam heating furnace adopts intelligent combustion control technology and sets different temperature range standards according to different steel types and production specifications.
[0026] The temperature range standard is that when producing φ6.5mm SWRCH22A steel with cold billet, the temperature of the second heating section of the three-stage walking beam heating furnace is controlled at 890℃, the temperature of the first heating section is controlled at 1080℃, and the temperature of the soaking section is controlled at 1120℃. When using cold billet for production, the temperature of each section will increase to varying degrees. The starting rolling temperature is controlled at 1010℃. Automatic combustion technology is adopted, and the temperature difference of the billet passing rod is controlled within 10℃.
[0027] 3. The molten steel after the heating furnace is produced into finished coils through rough rolling, intermediate rolling, pre-finishing rolling, finishing rolling, module machine and wire laying machine. Water-penetrating cooling is set before and after finishing rolling and after the module machine to adjust the cooling rate of the steel and control the grain deformation and phase change temperature.
[0028] The rough rolling and intermediate rolling areas use 14 horizontal and vertical alternating rolling mills, and the pre-finishing rolling area uses 14 horizontal and vertical alternating rolling mills and two Danieli finishing mills. A large reduction is adopted, and the material shape is controlled to be 18.9mm round; then it is cooled through two water tanks, and the water supply pressure of the water tank is controlled to be above 14Bar for water penetration to control the cooling rate of the rolled piece. After passing through the 3# flying shear head, it enters the Danieli finishing mill unit. At this time, the temperature is controlled to 920±10℃. The finishing mill unit uses a one-to-two 45° top-crossing finishing mill, and uses a roller ring hole type that is universal for all specifications. Different sets of rolling mills are used according to different production specifications, and the exit out-of-roundness is controlled within 0.3mm.
[0029] After the finishing mill, the rolled piece is cooled again and passes through three water tanks. The temperature of the rolled piece is controlled to 920℃ before entering the dual-module unit. After passing through four rolling mills, the required product size is finally achieved. After the finished product is finished, it is evenly cooled in sections through three water tanks. Finally, the spinning temperature is also controlled at 920±10℃ to ensure that the product surface is dense, uniform and smooth.
[0030] 4. After the spinning machine, the steel passes through the Stelmor air cooling line to adjust the internal structure of the finished steel to ferrite + pearlite.
[0031] A Danieli high-speed flying shear is installed in front of the spinning machine to automatically shear steel with excessive head and tail dimensions and excessive mechanical properties. After spinning, the steel passes through the Stelmor air cooling line, where an insulation cover is used to slowly cool the finished product and adjust the product structure to ensure that the final product contains pearlite and ferrite without a hardened layer.
[0032] Embodiment 1:
[0033] A high-speed wire production line of an enterprise uses this process to produce 6.5 specification SWRCH22A cold heading steel, using 165mm*165mm*12000mm square billets, production furnace numbers are L1G1Z224D00574, L1G1Z224D00575, the main chemical composition weight percentage of the billet is C: 0.195, Si: 0.05, Mn: 0.88, Al: 0.03, a total of 194.22 tons were produced, the second heating stage temperature was 890℃, the first heating stage temperature was 108 0℃, soaking section temperature 1120℃, rolling start temperature 1010℃, billet pass rod temperature difference controlled at 8℃; 6 rolling mills in the rough rolling area, material type 72.5*72mm, 4 rolling mills in the intermediate rolling area, material type 41*40mm, 4 horizontal and vertical alternating rolling mills and 2 Danieli BGV finishing rolling mills in the pre-finishing rolling area, material type 18.9*18.9mm, cooled to 920℃ through 1# and 2# water tanks, and entered into 8 Danieli finishing mills after using 3# flying shear head, with cross-sectional area controlled at 52.3mm 2 After leaving the finishing mill, it continues to be cooled in a water tank to control the temperature to 920℃, and finally enters the Danieli sizing unit. After being rolled out by four sets of roller rings, the finished product is produced. The out-of-roundness can be controlled within 0.3mm. After the finished product is produced, it is cooled in water after rolling to control the temperature at 930℃. Finally, it is collected through the Stelmor air cooling line and the loose coil steel is slowly cooled using a heat preservation cover. The product tensile strength is between 490 and 510Mpa, and the cross-sectional shrinkage rate is above 65%. The performance is better than the technical standard.
[0034] Embodiment 2:
[0035] A high-speed wire production line of a certain enterprise uses this process to produce 6.5 specification SWRCH22A cold heading steel, using 165mm*165mm*12000mm square billets, and the production furnace numbers are L1G1Z224F01196, L1G1Z224F01194, L1G1Z224F01189, L1G1Z224F01187, L1G1Z224F01185, L1G1Z224F01197, L1G1 Z224F01181, L1G1Z224F01188, L1G1Z224F01202, L1G1Z224F01191, the steel billets use the main chemical components by weight percentage C: 0.2, Si: 0.05, Mn: 0.8, Al: 0.03, a total of 1320.447 tons were produced, using the same process, the product tensile strength is 485~510Mpa, the cross-sectional shrinkage rate is above 68%, and the performance is better than the technical standard.
[0036] The controlled rolling and controlled cooling method of the present invention significantly reduces the alloy composition and increases the hourly output compared to the hot rolling production mode. Compared with hot rolling production, it can reduce the cost by 85 yuan / ton, which greatly reduces the production cost. By controlling the heating temperature, rolling temperature, deformation amount, and segmented cooling to enhance the plasticity and strength of the finished steel, the alloy elements can be adjusted at the same time, reducing the consumption of precious metal resources and reducing production costs. The three-stage step-beam heating furnace uses pulse combustion technology for automatic combustion to ensure the uniform temperature of the steel rods. At the same time, the speed of the step-beam is increased, and the spaced furnace entry process is designed to reduce the length of time the billet is in the furnace, control grain growth, and improve product performance. In the low-speed zone, a large amount of reduction is controlled to cause severe deformation of the grains to improve the final performance of the product; the water tank is modified to increase the nozzle reaction speed, control the cooling rate of the rolled piece, and control the temperature of the rolled piece through process cooling and post-rolling cooling to ensure product performance indicators.
[0037] The present invention is not limited to the above-mentioned implementation modes, and anyone should be aware of the structural changes made under the enlightenment of the present invention, and all those having the same or similar technical solutions as the present invention fall within the protection scope of the present invention.
[0038] The techniques, shapes, and structural parts not described in detail in the present invention are all well-known techniques.
Claims
1. A method for producing 6.5 gauge wire coil SWRCH22A cold heading steel, characterized in that: The following steps are involved: S1. The chemical composition of the steel billet used for continuous casting is C: 0.18-0.20, Si: 0.03-0.05, Mn: 0.7-0.9, Al: 0.025-0.035, S and P impurity elements ≤ 0.015, nitrogen content ≤ 70ppm, and the rest is iron and unavoidable impurities; S2, the continuous casting billet is evenly heated in a three-stage walking beam heating furnace; S3. The molten steel after being discharged from the heating furnace is subjected to rough rolling, intermediate rolling, pre-finishing rolling, finishing rolling, module mill, and wire laying machine to produce finished coils. Water-penetrating cooling is set before and after finishing rolling and after the module mill to adjust the cooling rate of the steel and control the grain deformation and phase change temperature. S4, after the spinning machine, it passes through the Stelmor air cooling line to adjust the internal structure of the finished steel to ferrite + pearlite.
2. The method for producing 6.5 gauge wire coil SWRCH22A cold heading steel according to claim 1, characterized in that: The size of the continuous casting billet in step S1 is 165mm*165mm*12000mm.
3. The method for producing 6.5 gauge wire coil SWRCH22A cold heading steel according to claim 1, characterized in that: The three-stage walking beam heating furnace in step S2 adopts intelligent combustion control technology and sets different temperature range standards according to different steel types and production specifications.
4. The method for producing 6.5 gauge wire coil SWRCH22A cold heading steel according to claim 3, characterized in that: The temperature range standard is that when producing SWRCH22A steel with a specification of φ6.5mm with cold billets, the temperature of the second heating section of the three-stage walking beam heating furnace is controlled at 890°C, the temperature of the first heating section is controlled at 1080°C, and the temperature of the soaking section is controlled at 1120°C. When using cold billets for production, the temperature of each section increases to varying degrees, the starting rolling temperature is controlled at 1010°C, and automatic combustion technology is adopted. The temperature difference of the billet passing rod is controlled within 10°C.
5. The method for producing 6.5 gauge wire coil SWRCH22A cold heading steel according to claim 1, characterized in that: In the step S3, 14 horizontal and vertical alternating rolling mills are used in the rough rolling and intermediate rolling areas, and 14 horizontal and vertical alternating rolling mills and two Danieli finishing mills are used in the pre-finishing rolling area. The material shape is controlled to be a circle of 18.9 mm. Subsequently, the material is cooled through two water tanks, and the water supply pressure of the water tank is controlled to be above 14 Bar to control the cooling rate of the rolled piece. After passing through the 3# flying shear head, the rolled piece enters the Danieli finishing mill group. At this time, the temperature is controlled to 920±10°C. The finishing mill group uses a one-to-two 45° top-cross finishing mill. Through the roller ring hole type that is universal for all specifications, different numbers of rolling mills are used according to different production specifications, and the outlet out-of-roundness is controlled within 0.3 mm.
6. The method for producing 6.5 gauge wire rod coil SWRCH22A cold heading steel according to claim 5, characterized in that: After the finishing mill, the rolled piece is cooled again, passes through three water tanks, and the temperature of the rolled piece is controlled to 920°C before entering the dual-module unit. After passing through four rolling mills, the required product size is finally achieved. After the finished product is evenly cooled in sections through three water tanks, the spinning temperature is finally controlled at 920±10°C to ensure that the product surface is dense, uniform and smooth.
7. The method for producing 6.5 gauge wire coil SWRCH22A cold heading steel according to claim 1, characterized in that: A Danieli high-speed flying shear device is installed in front of the spinning machine in step S4 to automatically shear the steel with excessive head and tail dimensions and excessive mechanical properties. After spinning, the steel passes through the Stelmor air cooling line, where an insulation cover is used to slowly cool the finished product and adjust the product structure to ensure that the final product contains pearlite and ferrite without a hardened layer.