Multi-specification self-adaptive temperature control rolling technology in bar rolling process

Abstract

The invention relates to the technical field of steel industry, and discloses a multi-specification self-adaptive temperature control rolling process in a bar rolling process, which comprises the following steps: S1, a blank pretreatment stage, S2, an intelligent heating stage, S3, a high-pressure water descaling stage, S4, a multi-pass rolling stage, S5, on-line size monitoring, S6, a post-rolling controlled cooling stage and S7, a finishing stage. The production change time is shortened, on the basis of a specification-temperature-roll gap correlation model, automatic matching of phi 20-100 mm full-specification parameters is achieved, the production change time is shortened to be within 15 minutes (reduced by 60% or above compared with a traditional process), automatic switching of equipment parameters such as an MES system correlation rolling plan, a water cooling box and descaling pressure is achieved, manual adjustment errors are avoided, the multi-specification production qualification rate is increased to 99.5%, and the production efficiency is improved. According to the scheme, the temperature control precision is improved, the product performance is optimized, the three-section temperature of the heating furnace is controlled through the fuzzy PID algorithm, and the bearing steel heating temperature equalization time is shortened by 30%.

Description

Technical Field

[0001] This invention relates to the field of steel industry technology, specifically to a multi-specification adaptive temperature control rolling process for bar rolling. Background Technology

[0002] Bar rolling is a crucial step in the steel industry, with its products widely used in high-end fields such as automobile manufacturing, construction machinery, and rail transportation. As downstream industries increasingly demand higher dimensional accuracy, mechanical properties, and surface quality from bar stock, traditional rolling processes are gradually revealing the following problems: Poor compatibility across multiple specifications Traditional processes require individual rolling parameters for different bar sizes (Φ20~100mm). When changing sizes, key parameters such as mill roll gap and cooling water volume need to be manually adjusted, resulting in long changeover times (average 40~60 minutes) and a high risk of dimensional deviations due to improper parameter matching (pass rate is only 92%~95%). For example, Φ20mm small-diameter bars are prone to head bending due to rolling temperature fluctuations, while Φ100mm large-diameter bars suffer from excessive differences in mechanical properties due to uneven cooling.

[0003] Insufficient temperature control accuracy Traditional heating furnaces use fixed temperature control in certain sections, which cannot dynamically adjust the heating rate according to the billet specifications. This results in uneven dissolution of carbides in high-end steels such as bearing steel (with network carbides reaching level 3-4). Post-rolling cooling often relies on experience to set the water volume, and the fatigue life of materials such as spring steel fluctuates by more than 15% due to fluctuations in the cooling rate (±5℃ / s). Summary of the Invention

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a multi-specification adaptive temperature control rolling process for bar rolling, which has advantages such as improved multi-specification compatibility and shortened changeover time, thus solving the problem of poor multi-specification compatibility.

[0005] (II) Technical Solution To achieve the above-mentioned goals of improving multi-specification compatibility and shortening production changeover time, the present invention provides the following technical solution: a multi-specification adaptive temperature control rolling process for bar rolling, including S1 billet pretreatment stage, S2 intelligent heating stage, S3 high-pressure water descaling stage, S4 multi-pass rolling stage, S5 online dimension monitoring, S6 post-rolling controlled cooling stage and S7 finishing stage, wherein the S1 billet pretreatment stage includes S101 billet screening and classification and S102 surface pretreatment; The S2 intelligent heating stage includes S201 segmented temperature control heating and S202 adaptive heat preservation. Among them, the S3 high-pressure water descaling stage: three-stage variable pressure descaling: a three-stage descaling device is adopted, which automatically switches the water pressure according to the billet specifications; Descaling effect monitoring: After descaling, a visual inspection system is set up. When the residual iron oxide scale area is >5%, a second descaling is automatically triggered (pressure increased by 10%) to ensure the cleanliness of the rolled piece surface; The S4 multi-pass rolling stage includes the S401 roughing mill (1-6 stands), S402 head removal and heat preservation control, S403 intermediate mill (7-12 stands), S404 dynamic distribution of cooling water, S405 finishing mill and sizing mill, and S406 finishing mill (17-20 stands). Among them, S5 online size monitoring: laser diameter measuring instruments are installed at the finishing mill and sizing exit, with a sampling frequency of 100Hz. When the diameter deviation exceeds ±0.1mm, the sizing roll gap is automatically adjusted (adjustment response time <0.5s). Among them, the S6 post-rolling controlled cooling stage includes the S601 graded water cooling process and the S602 water cooling box adaptive switching. The S7 finishing stage includes S701 cooling bed optimization and S702 length shearing and flaw detection.

[0006] Preferably, the S101 billet screening and classification: According to the steel compression ratio requirements, the billets are divided into continuously cast billets (150 cubic meters, 240 cubic meters, and 280 cubic meters) and rolled billets (provided by the No. 2 bar workshop). The dimensional deviation of the billets is detected by a laser diameter gauge (allowable error ≤ ±1 mm). Billets with a curvature > 5 mm / m need to be straightened in advance. S102 Surface Pretreatment: For cold-charged billets, a combined treatment of shot blasting and grinding is adopted: the shot blasting pressure is controlled at 0.4~0.6MPa to remove the surface iron oxide scale; the grinding depth is ≤0.5mm to ensure that there are no cracks or scars on the surface. Hot-charged billets (temperature ≥600℃) directly enter the hot-charged roller conveyor to shorten the heating time.

[0007] Preferably, the S201 segmented temperature control heating: The walking beam heating furnace is divided into a preheating section (600~800℃), a heating section (800~1050℃), and a soaking section (1050~1200℃). The billet temperature is monitored in real time by an infrared thermometer, and the gas flow rate of each section is adjusted by a fuzzy PID algorithm (the natural gas pressure is kept stable at 0.2~0.25MPa). Bearing steel (such as GCr15): Heat to 1150~1200℃, with a soaking time of ≥2h to ensure uniform dissolution of carbides; Gear steel (such as 20CrMnTi): Heat to 1050~1100℃, and control the heating rate ≤150℃ / h; S202 Adaptive Thermal Insulation: The heat preservation time is dynamically adjusted according to the billet specifications: 3.5 hours for 280 cubic meter billets, 3 hours for 240 cubic meter billets, and 2.5 hours for 150 cubic meter billets. Automatic scheduling is achieved by linking billet information through the MES system.

[0008] Preferably, the S401 roughing mill unit (1-6 stands): Micro-tension rolling adopts an alternating horizontal and vertical arrangement, and the roll gap setting uses an adaptive algorithm: it is dynamically adjusted according to the billet temperature (collected every 30 seconds), and the roll gap increases by 0.1 mm for every 50℃ decrease in temperature; 1H stand: roll gap 80~100mm, rolling speed 0.4~0.6m / s; 6V stand: roll gap 20~30mm, rolling speed 0.8~1.2m / s.

[0009] Preferably, the S402 head-off heat preservation control: The transverse cooling stand adjusts the slow cooling time according to the specifications of the rolled piece: for rolled pieces with Φ>80mm, the slow cooling time is 850~900℃; for rolled pieces with Φ≤80mm, the slow cooling time is 800~850℃. The power of the stand fan (0~50Hz) is adjusted by infrared temperature measurement feedback.

[0010] Preferably, in the S403, there are 7-12 rolling mill stands: The looper is self-adaptive and adjustable. The height of the looper is set to 120~150mm. The looper volume is detected by a laser sensor. When the deviation exceeds ±20mm, the speed of the front and rear frames is automatically adjusted (adjustment range ±0.5%). 7H frame: elongation 1.2~1.3, motor current controlled at 30%~40% of rated value; 12V stand: elongation 1.1~1.2, rolling speed 1.5~2.5m / s.

[0011] Preferably, the S404 cooling water is dynamically distributed: A closed-loop flow control system is adopted to adjust the cooling water volume according to the workpiece temperature (target 850~900℃): 80~120m³ of water for Φ60~100mm workpieces. 3 / h, water flow rate for Φ20~59mm rolled products: 50~80m³ / h 3 / h; S405 finishing and reducing mill unit: Low-temperature rolling control: A water-cooling box is installed at the pre-finishing mill exit, and a "three-stage" cooling system is adopted: strong cooling in the front stage (water temperature ≤30℃), uniform temperature in the middle stage, and fine adjustment in the rear stage, to ensure that the temperature entering the finishing mill is stable at 750~850℃; S406 finishing mill (17-20 stands): tension-free rolling, roll gap accuracy controlled within ±0.05mm. Sizing and reducing mill: KOCKS mill is used, and the pass type is automatically switched according to the specifications. Φ20~30mm is rolled in 4 stands, and Φ30~100mm is rolled in 5 stands.

[0012] Preferably, the S601 staged water cooling process: Select the cooling path according to the characteristics of the steel: Spring steel (60Si2Mn): adopt "water cooling + air cooling", cooling rate 15~20℃ / s, final cooling temperature 600~650℃; Non-quenched and tempered steel: slow cooling pit insulation (300~400℃×4h) to avoid pearlite network precipitation; S602 water-cooled box adaptive switching: By linking the rolling schedule through the MES system, 3-stage water cooling is activated for rolled pieces with Φ>50mm, and 2-stage water cooling is activated for rolled pieces with Φ≤50mm. When water cooling is not required, the system automatically switches to the bypass roller table (switching time <10s).

[0013] Preferably, the S701 cooling bed optimizes cooling: The step-type cooling bed adopts zoned temperature control: the inlet section (temperature ≥600℃) is covered with an insulation cover, the middle section (400~600℃) is naturally cooled, and the outlet section (≤400℃) is forced to be cooled by air, ensuring a cooling rate of ≤5℃ / min.

[0014] Preferably, the S702 length shearing and flaw detection: The cold shearing accuracy is ±5mm. For high-end bearing steel products, "ultrasonic + magnetic particle" combined flaw detection is adopted, and the flaw detection speed is matched with the roller speed (1~3m / s). The defect detection rate is ≥99%.

[0015] (III) Beneficial Effects Compared with the prior art, the present invention provides a multi-specification adaptive temperature control rolling process for bar rolling, which has the following beneficial effects: 1. This bar rolling process features a multi-specification adaptive temperature control rolling technology. This solution improves multi-specification compatibility and shortens changeover time. Based on the specification-temperature-roll gap correlation model, it achieves automatic matching of parameters for all specifications from Φ20 to 100mm, reducing changeover time to less than 15 minutes (more than 60% less than traditional processes). By linking the rolling plan with the MES system, equipment parameters such as water cooling box and descaling pressure are automatically switched, avoiding manual adjustment errors and increasing the multi-specification production qualification rate to 99.5%.

[0016] 2. The multi-specification adaptive temperature control rolling process in the bar rolling process improves temperature control accuracy and optimizes product performance. The fuzzy PID algorithm is used to control the temperature of the three sections of the heating furnace, which shortens the heating uniformity time of bearing steel by 30% and reduces the carbide network level to level 1-2. The post-rolling graded water cooling process controls the cooling rate fluctuation of spring steel within ±2℃ / s, improves fatigue life stability by 20%, and reduces the pearlite network precipitation rate to below 0.5% for non-quenched and tempered steel through precise heat preservation in the slow cooling pit.

[0017] 3. The multi-specification adaptive temperature control rolling process in this bar rolling process enhances the synergy between descaling and rolling, improves surface quality, and the three-stage variable pressure descaling system dynamically adjusts the pressure according to the billet specifications. The residual iron oxide scale of 280 square billet is reduced to below 1%, and the surface erosion of 150 square billet is reduced by 50%. With the linkage of visual inspection and secondary descaling, the surface defect rate of rolled parts is reduced to 0.3%, and the grinding cost is reduced by 40%.

[0018] 4. The multi-specification adaptive temperature control rolling process in this bar rolling process improves the level of intelligence, ensures dimensional accuracy, and achieves real-time closed-loop control of the laser diameter measuring instrument and the sizing roll gap. The diameter deviation of Φ20~100mm bars is controlled within ±0.08mm, and the out-of-roundness is ≤0.1mm. The looper adaptive adjustment reduces the tension fluctuation amplitude to ±0.2%, solving the problems of "steel pulling" for large-specification bars and "steel piling" for small-specification bars, and increasing the mill operating rate to over 90%.

[0019] 5. The multi-specification adaptive temperature control rolling process in the bar rolling process reduces energy consumption and costs. Adaptive heat preservation and dynamic water volume control reduce gas consumption per ton of steel by 8% and cooling water consumption by 15%. Intelligent parameter optimization reduces the number of trial rollings, increases metal yield by 1.2%, and saves more than 3 million yuan in production costs annually. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides a technical solution, specifically a multi-specification adaptive temperature-controlled rolling process for bar rolling, comprising the following processes: S1 billet pretreatment stage: S101 billet screening and classification: According to the steel compression ratio requirements, the billets are divided into continuously cast billets (150 cubic meters, 240 cubic meters, and 280 cubic meters) and rolled billets (provided by the No. 2 bar workshop). The dimensional deviation of the billets is detected by a laser diameter gauge (allowable error ≤ ±1 mm). Billets with a curvature > 5 mm / m need to be straightened in advance. S102 Surface Pretreatment: For cold-charged billets, a combined treatment of shot blasting and grinding is adopted: the shot blasting pressure is controlled at 0.4~0.6MPa to remove the surface iron oxide scale; the grinding depth is ≤0.5mm to ensure that there are no cracks or scabs on the surface. Hot-charged billets (temperature ≥600℃) directly enter the hot-charged roller conveyor to shorten the heating time. S2 Intelligent Heating Stage: S201 segmented temperature control heating: The walking beam heating furnace is divided into a preheating section (600~800℃), a heating section (800~1050℃), and a soaking section (1050~1200℃). The billet temperature is monitored in real time by an infrared thermometer, and the gas flow rate of each section is adjusted by a fuzzy PID algorithm (the natural gas pressure is kept stable at 0.2~0.25MPa). Bearing steel (such as GCr15): Heat to 1150~1200℃, with a soaking time of ≥2h to ensure uniform dissolution of carbides; Gear steel (such as 20CrMnTi): Heat to 1050~1100℃, and control the heating rate ≤150℃ / h; S202 Adaptive Thermal Insulation: The heat preservation time is dynamically adjusted according to the billet specifications: 3.5 hours for 280 cubic meter billets, 3 hours for 240 cubic meter billets, and 2.5 hours for 150 cubic meter billets. Automatic scheduling is achieved by linking billet information through the MES system. S3 High-Pressure Water Descaling Stage: Three-Stage Variable Pressure Descaling: A three-stage descaling device is adopted, which automatically switches the water pressure according to the billet specifications; Descaling effect monitoring: After descaling, a visual inspection system is set up. When the residual iron oxide scale area is >5%, a second descaling is automatically triggered (pressure increased by 10%) to ensure the cleanliness of the rolled piece surface; S4 multi-pass rolling stage: S401 roughing mill (stands 1-6): Micro-tension rolling adopts an alternating horizontal and vertical arrangement, and the roll gap setting uses an adaptive algorithm: it is dynamically adjusted according to the billet temperature (collected every 30 seconds), and the roll gap increases by 0.1 mm for every 50℃ decrease in temperature; 1H stand: roll gap 80~100mm, rolling speed 0.4~0.6m / s; 6V stand: roll gap 20~30mm, rolling speed 0.8~1.2m / s; S402 head-off insulation control: The transverse cooling stand adjusts the slow cooling time according to the specifications of the rolled piece: for rolled pieces with Φ>80mm, the slow cooling time is 850~900℃; for rolled pieces with Φ≤80mm, the slow cooling time is 800~850℃. The power of the stand fan (0~50Hz) is adjusted by infrared temperature measurement feedback. S403 intermediate rolling mill (7-12 stands): The looper is self-adaptive and adjustable. The height of the looper is set to 120~150mm. The looper volume is detected by a laser sensor. When the deviation exceeds ±20mm, the speed of the front and rear frames is automatically adjusted (adjustment range ±0.5%). 7H frame: elongation 1.2~1.3, motor current controlled at 30%~40% of rated value; 12V stand: elongation 1.1~1.2, rolling speed 1.5~2.5m / s; S404 Dynamic Cooling Water Distribution: A closed-loop flow control system is adopted to adjust the cooling water volume according to the workpiece temperature (target 850~900℃): 80~120m³ of water for Φ60~100mm workpieces. 3 / h, water flow rate for Φ20~59mm rolled products: 50~80m³ / h 3 / h; S405 finishing and reducing mill unit: Low-temperature rolling control: A water-cooling box is installed at the pre-finishing mill exit, and a "three-stage" cooling system is adopted: strong cooling in the front stage (water temperature ≤30℃), uniform temperature in the middle stage, and fine adjustment in the rear stage, to ensure that the temperature entering the finishing mill is stable at 750~850℃; S406 finishing mill (17-20 stands): tension-free rolling, roll gap accuracy controlled within ±0.05mm. Sizing and reducing mill: KOCKS mill is used, and the pass type is automatically switched according to the specifications. Φ20~30mm is rolled in 4 stands, and Φ30~100mm is rolled in 5 stands; S5 online size monitoring: A laser diameter gauge is installed at the finishing mill and reducing sizing exit, with a sampling frequency of 100Hz. When the diameter deviation exceeds ±0.1mm, the reducing sizing roll gap is automatically adjusted (adjustment response time <0.5s). S6 Post-rolling controlled cooling stage: S601 staged water cooling process: Select the cooling path according to the characteristics of the steel: Spring steel (60Si2Mn): adopt "water cooling + air cooling", cooling rate 15~20℃ / s, final cooling temperature 600~650℃; Non-quenched and tempered steel: slow cooling pit insulation (300~400℃×4h) to avoid pearlite network precipitation; S602 water-cooled box adaptive switching: By linking the rolling schedule through the MES system, 3-stage water cooling is activated for rolled pieces with Φ>50mm, and 2-stage water cooling is activated for rolled pieces with Φ≤50mm. When water cooling is not required, it automatically switches to the bypass roller table (switching time <10s). S7 Refinement Stage: S701 Cooling Bed Optimization Cooling: The stepping cooling bed adopts zoned temperature control: the inlet section (temperature ≥600℃) opens the heat insulation cover, the middle section (400~600℃) is naturally cooled, and the outlet section (≤400℃) is forced air cooling to ensure a cooling rate ≤5℃ / min; S702 Length Shearing and Flaw Detection: Cold shearing accuracy is ±5mm. For high-end bearing steel products, a combination of ultrasonic and magnetic particle testing is used, with the testing speed matched to the roller conveyor speed (1~3m / s), and the defect detection rate is ≥99%. Furthermore, this solution enhances multi-specification compatibility and shortens changeover time. Based on a specification-temperature-roll gap correlation model, it achieves automatic parameter matching for all specifications from Φ20 to 100mm, reducing changeover time to less than 15 minutes (more than 60% less than traditional processes). By linking the rolling schedule with the MES system, the parameters of the water cooling box and descaling pressure equipment are automatically switched, avoiding manual adjustment errors and increasing the multi-specification production qualification rate to 99.5%. Furthermore, this solution improves temperature control accuracy and optimizes product performance. By using a fuzzy PID algorithm to control the three-stage temperature of the heating furnace, the heating uniformity time of bearing steel is shortened by 30%, and the carbide network level is reduced to level 1-2. The post-rolling graded water cooling process controls the cooling rate fluctuation of spring steel within ±2℃ / s, improves fatigue life stability by 20%, and reduces the pearlite network precipitation rate to below 0.5% for non-quenched and tempered steel through precise heat preservation in slow cooling pits. Furthermore, this solution enhances the synergy between descaling and rolling, improves surface quality, and dynamically adjusts the pressure according to the billet specifications of the three-stage variable pressure descaling system. The residual iron oxide scale rate of 280 square billets is reduced to below 1%, and the surface erosion of 150 square billets is reduced by 50%. Combined with visual inspection and secondary descaling, the surface defect rate of rolled products is reduced to 0.3%, and the grinding cost is reduced by 40%. Furthermore, this solution enhances the level of intelligence, ensures dimensional accuracy, and achieves real-time closed-loop control of the laser diameter measuring instrument and the sizing roll gap. The diameter deviation of Φ20~100mm bars is controlled within ±0.08mm, and the out-of-roundness is ≤0.1mm. The adaptive adjustment of the looper reduces the tension fluctuation amplitude to ±0.2%, solving the problems of "steel pulling" for large-diameter bars and "steel piling" for small-diameter bars, and increasing the mill operating rate to over 90%. Furthermore, this solution reduces energy consumption and costs. Adaptive insulation and dynamic water volume control reduce gas consumption per ton of steel by 8% and cooling water consumption by 15%. Intelligent parameter optimization reduces the number of trial rolling operations, increases metal yield by 1.2%, and saves more than 3 million yuan in production costs annually.

[0022] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-specification adaptive temperature-controlled rolling process for bar rolling, comprising: S1 billet pretreatment stage, S2 intelligent heating stage, S3 high-pressure water descaling stage, S4 multi-pass rolling stage, S5 online dimensional monitoring, S6 post-rolling controlled cooling stage, and S7 finishing stage, characterized in that: The S1 billet pretreatment stage includes S101 billet screening and classification and S102 surface pretreatment; The S2 intelligent heating stage includes S201 segmented temperature control heating and S202 adaptive heat preservation. Among them, the S3 high-pressure water descaling stage: three-stage variable pressure descaling: a three-stage descaling device is adopted, which automatically switches the water pressure according to the billet specifications; Descaling effect monitoring: After descaling, a visual inspection system is set up. When the residual iron oxide scale area is >5%, a second descaling is automatically triggered (pressure increased by 10%) to ensure the cleanliness of the rolled piece surface; The S4 multi-pass rolling stage includes the S401 roughing mill (1-6 stands), S402 head removal and heat preservation control, S403 intermediate mill (7-12 stands), S404 dynamic distribution of cooling water, S405 finishing mill and sizing mill, and S406 finishing mill (17-20 stands). Among them, S5 online size monitoring: laser diameter measuring instruments are installed at the finishing mill and sizing exit, with a sampling frequency of 100Hz. When the diameter deviation exceeds ±0.1mm, the sizing roll gap is automatically adjusted (adjustment response time <0.5s). Among them, the S6 post-rolling controlled cooling stage includes the S601 graded water cooling process and the S602 water cooling box adaptive switching. The S7 finishing stage includes S701 cooling bed optimization and S702 length shearing and flaw detection.

2. The multi-specification adaptive temperature control rolling process for bar rolling according to claim 1, characterized in that: The S101 billet screening and classification: According to the steel compression ratio requirements, the billets are divided into continuously cast billets (150 cubic meters, 240 cubic meters, and 280 cubic meters) and rolled billets (provided by the No. 2 bar workshop). The dimensional deviation of the billets is detected by a laser diameter gauge (allowable error ≤ ±1 mm). Billets with a curvature > 5 mm / m need to be straightened in advance. S102 Surface Pretreatment: For cold-charged billets, a combined treatment of shot blasting and grinding is adopted: the shot blasting pressure is controlled at 0.4~0.6MPa to remove the surface iron oxide scale; the grinding depth is ≤0.5mm to ensure that there are no cracks or scars on the surface. Hot-charged billets (temperature ≥600℃) directly enter the hot-charged roller conveyor to shorten the heating time.

3. The multi-specification adaptive temperature control rolling process for bar rolling according to claim 1, characterized in that: The S201 segmented temperature control heating: The walking beam heating furnace is divided into a preheating section (600~800℃), a heating section (800~1050℃), and a soaking section (1050~1200℃). The billet temperature is monitored in real time by an infrared thermometer, and the gas flow rate of each section is adjusted by a fuzzy PID algorithm (the natural gas pressure is kept stable at 0.2~0.25MPa). Bearing steel (such as GCr15): Heat to 1150~1200℃, with a soaking time of ≥2h to ensure uniform dissolution of carbides; Gear steel (such as 20CrMnTi): Heat to 1050~1100℃, and control the heating rate ≤150℃ / h; S202 Adaptive Thermal Insulation: The heat preservation time is dynamically adjusted according to the billet specifications: 3.5 hours for 280 cubic meter billets, 3 hours for 240 cubic meter billets, and 2.5 hours for 150 cubic meter billets. Automatic scheduling is achieved by linking billet information through the MES system.

4. The multi-specification adaptive temperature control rolling process for bar rolling according to claim 1, characterized in that: The S401 roughing mill (stands 1-6): Micro-tension rolling adopts an alternating horizontal and vertical arrangement, and the roll gap setting uses an adaptive algorithm: it is dynamically adjusted according to the billet temperature (collected every 30 seconds), and the roll gap increases by 0.1 mm for every 50℃ decrease in temperature; 1H stand: roll gap 80~100mm, rolling speed 0.4~0.6m / s; 6V stand: roll gap 20~30mm, rolling speed 0.8~1.2m / s.

5. The multi-specification adaptive temperature control rolling process for bar rolling according to claim 1, characterized in that: The S402 head-off insulation control: The transverse cooling stand adjusts the slow cooling time according to the specifications of the rolled piece: for rolled pieces with Φ>80mm, the slow cooling time is 850~900℃, and for rolled pieces with Φ≤80mm, the slow cooling time is 800~850℃. The power of the stand fan (0~50Hz) is adjusted by infrared temperature measurement feedback.

6. The multi-specification adaptive temperature control rolling process for bar rolling according to claim 1, characterized in that: The S403 intermediate rolling mill (7-12 stands): The looper is self-adaptive and adjustable. The height of the looper is set to 120~150mm. The looper volume is detected by a laser sensor. When the deviation exceeds ±20mm, the speed of the front and rear frames is automatically adjusted (adjustment range ±0.5%). 7H frame: elongation 1.2~1.3, motor current controlled at 30%~40% of rated value; 12V stand: elongation 1.1~1.2, rolling speed 1.5~2.5m / s.

7. The multi-specification adaptive temperature control rolling process for bar rolling according to claim 1, characterized in that: The S404 cooling water dynamic distribution: A closed-loop flow control system is adopted to adjust the cooling water volume according to the workpiece temperature (target 850~900℃): 80~120m³ for Φ60~100mm workpieces. 3 / h, water flow rate for Φ20~59mm rolled products: 50~80m³ / h 3 / h; S405 finishing and reducing mill unit: Low-temperature rolling control: A water-cooling box is installed at the pre-finishing mill exit, and a "three-stage" cooling system is adopted: strong cooling in the front stage (water temperature ≤30℃), uniform temperature in the middle stage, and fine adjustment in the rear stage, to ensure that the temperature entering the finishing mill is stable at 750~850℃; S406 finishing mill (17-20 stands): tension-free rolling, roll gap accuracy controlled within ±0.05mm. Sizing and reducing mill: KOCKS mill is used, and the pass type is automatically switched according to the specifications. Φ20~30mm is rolled in 4 stands, and Φ30~100mm is rolled in 5 stands.

8. The multi-specification adaptive temperature control rolling process for bar rolling according to claim 1, characterized in that: The S601 staged water cooling process: Select the cooling path according to the characteristics of the steel: Spring steel (60Si2Mn): adopt "water cooling + air cooling", cooling rate 15~20℃ / s, final cooling temperature 600~650℃; Non-quenched and tempered steel: slow cooling pit insulation (300~400℃×4h) to avoid pearlite network precipitation; S602 water-cooled box adaptive switching: By linking the rolling schedule through the MES system, 3-stage water cooling is activated for rolls with Φ>50mm, and 2-stage water cooling is activated for rolls with Φ≤50mm. When water cooling is not required, the system automatically switches to the bypass roller table (switching time <10s).

9. The multi-specification adaptive temperature control rolling process for bar rolling according to claim 1, characterized in that: The S701 cooling bed features optimized cooling: The step-type cooling bed adopts zoned temperature control: the inlet section (temperature ≥600℃) is covered with an insulation cover, the middle section (400~600℃) is naturally cooled, and the outlet section (≤400℃) is forced to be cooled by air, ensuring a cooling rate of ≤5℃ / min.

10. The multi-specification adaptive temperature control rolling process for bar rolling according to claim 1, characterized in that: The S702 length shearing and flaw detection: The cold shearing accuracy is ±5mm. For high-end bearing steel products, "ultrasonic + magnetic particle" combined flaw detection is adopted, and the flaw detection speed is matched with the roller speed (1~3m / s). The defect detection rate is ≥99%.