Online cooling and transporting treatment method for rolled bars

Abstract

The invention relates to the technical field of steel and iron, and discloses an online cooling and transporting treatment method after bar rolling, which comprises the following steps: S1, carrying out gradient temperature control preparation (0-10 seconds after rolling) at a cooling front section, S2, carrying out segmented precise cooling (10-60 seconds after rolling) at a cooling middle section, S3, carrying out collaborative scheduling and anti-deformation treatment (60 seconds after cooling and stacking finished products) at a transporting section, and S4, carrying out quality feedback and process iteration (full-process closed loop). According to the scheme, precise temperature control and quality improvement are achieved, and subsection cooling cooperation is achieved, specifically, a cooling channel is divided into a rapid cooling area, a slow cooling area and a uniform temperature area, infrared temperature measurement and thermocouple real-time monitoring are combined, and the cooling rate of 20-30 DEG C / s is adopted for different steel types (for example, HRB400 needs to rapidly inhibit grain growth; and (65Mn needs to control martensite generation, and the speed of a slow cooling area is adjusted to 5-10 DEG C / s), the cooling strength (the opening degree of an aerial fog nozzle, the cooling water flow and the gas-water ratio) is dynamically adjusted, the bar cooling curve fitting rate is larger than or equal to 95%, and the phase change uniformity is improved.

Description

Technical Field

[0001] The invention relates to the technical field of steel, and in particular to an online cooling and transportation processing method for rolling bars. Background Art

[0002] In the steel industry's bar rolling production process, online cooling and transportation of bars after rolling are key processes that determine product quality and production efficiency. Currently, traditional processing methods have many technical challenges that need to be solved: From the perspective of cooling process, the temperature of the bar after rolling is as high as 850-950℃, and the cooling process needs to be quickly and accurately controlled to regulate the transformation of the metallographic structure. However, most existing cooling systems adopt a single mode, such as fixed flow spray or mist cooling, which cannot be dynamically adapted according to the bar steel type (such as HRB400, 65Mn and other steels with different alloy compositions), rolling speed (dynamic changes of 5-15m / min), and finished product specifications (diameter 10-50mm, length 6-12m difference). This leads to uneven cooling of the bar and the problem of asynchronous phase transformation from austenite to ferrite / pearlite, which directly causes grain growth and internal stress concentration, resulting in large fluctuations in the mechanical properties of the bar (such as hardness deviation of up to ±20HB or above), the product qualification rate is difficult to maintain stably above 98%, which has a significant impact on the production of high value-added special steel bars.

[0003] During transportation, cooled bars need to be transferred from the cooling channel to the stacking area. Traditional roller conveyor transport lacks intelligent coordination mechanisms. For large-sized (diameter ≥ 30mm) and high-carbon steel (such as 65Mn) bars, continuous high-speed transportation can easily cause thermal deformation due to uneven residual heat distribution, with curvature exceeding 0.5mm / m. Subsequent manual straightening is time-consuming and labor-intensive, increasing processing costs. For small-sized, low-alloy bars, the mismatch between the transportation and cooling rhythms prolongs the production cycle. Furthermore, bar shaping before stacking relies on fixed pressure straightening wheels, which cannot dynamically adjust pressure based on the bar's real-time straightness. This results in poor stacking uniformity, impacting storage and subsequent further processing (such as machining cutting stability). Summary of the Invention

[0004] (1) Technical problems solved In response to the shortcomings of the existing technology, the present invention provides an online cooling and transportation processing method for bars after rolling, which has the advantages of precise temperature control and quality improvement, and solves the problem of uneven cooling of bars.

[0005] (2) Technical solution To achieve the above-mentioned precise temperature control and quality improvement purposes, the present invention provides the following technical solutions: a method for online cooling and transportation of bar materials after rolling, comprising S1 cooling front section: gradient temperature control preparation (0-10s after rolling), S2 cooling middle section: segmented precision cooling (10-60s after rolling), S3 transportation section: coordinated scheduling and anti-deformation treatment (60s after cooling to finished product stacking), and S4 quality feedback and process iteration (full process closed loop). The S1 cooling front section: gradient temperature control preparation (0-10s after rolling) includes S101 waste heat collection and analysis and S102 cooling channel pre-adjustment; Among them, S2 cooling middle section: segmented precise cooling (10-60s after rolling) includes S201 multi-zone cooling coordinated control and S202 intelligent deviation correction; Among them, S3 transport section: coordinated scheduling and anti-deformation treatment (60s after cooling to finished product stacking) includes S301 transport roller intelligent adaptation and S302 pre-stacking shaping treatment; Among them, S4 quality feedback and process iteration (full process closed loop) includes S401 online quality monitoring and S402 process iteration optimization.

[0006] Preferably, the S101 waste heat collection and analysis: An infrared thermometer (accuracy of ±1°C, sampling frequency of 50Hz) installed at the mill exit is used to collect the surface temperature of freshly rolled bars in real time (target range 850-950°C). Using the edge computing module, a temperature-performance correlation model is established based on historical rolling data (steel type, rolling speed, and finished product specifications) to predict the phase change process of the bars at the current temperature, providing a basis for cooling parameters.

[0007] Preferably, the S102 cooling channel is pre-adjusted: Before the bar enters the cooling section, the system automatically adjusts the cooling channel based on the temperature prediction results: The mist cooling nozzle opening (adjustable range 0-100%, accuracy ±5%) controls the mixing ratio of compressed air and cooling water (adjustable air-water ratio 10:1-50:1), and presets the initial cooling intensity for different steel grades (such as HRB400, which requires rapid cooling to inhibit grain growth). The roller conveyor speed (5-15m / min stepless speed regulation) matches the bar length (6-12m) with the cooling rhythm to ensure that the entire length of the bar is evenly cooled.

[0008] Preferably, the multi-zone cooling coordinated control in S201: The cooling channel is divided into three control zones (rapid cooling zone, slow cooling zone, and uniform temperature zone), and each control zone is equipped with an independent temperature closed-loop control system: Rapid cooling zone (Zone 1, length 3-5m): High-pressure atomization cooling (pressure 0.8-1.2MPa) is adopted, and the cooling water flow rate (20-50m 3 / h), quickly reduce the surface temperature of the bar from 800-900℃ to 650-700℃, and control the cooling rate at 20-30℃ / s to trigger the austenite to ferrite / pearlite phase transformation; Slow cooling zone (Zone 2, length 4-6m): switch to low-pressure spray cooling (pressure 0.2-0.5MPa), and adjust the flow rate to 10-30m 3 / h, the cooling rate is reduced to 5-10℃ / s to ensure phase change uniformity and avoid internal stress; Temperature equalization zone (Zone 3, length 2-4m): Turn off active cooling and use the residual heat inside the bar for self-tempering. Use thermocouples (arranged at a spacing of 1.5m) to monitor the core temperature in real time. When the temperature difference between the surface and the core is ≤50℃, the temperature equalization is determined to be completed and enter the transportation stage.

[0009] Preferably, the S202 intelligent deviation correction: If the temperature monitoring value of a control area deviates from the set value by more than ±10°C, the system will automatically trigger: Dynamic compensation of nozzle groups (if the temperature in the quenching zone is too high, add 2-4 groups of spare nozzles to increase the opening to 30-50%); Fine-tune the roller speed (when the deviation is 10-20°C, the speed is adjusted by ±0.5m / min) to ensure that the cooling curve fits the target process (e.g. the error of the cooling curve of Q235 steel is ≤5%).

[0010] Preferably, the S301 transport roller is intelligently adapted to: The cooled bars enter the transport roller. The system automatically selects the transport mode based on the bar specifications (diameter 10-50mm, length 6-12m) and the temperature after cooling (≤400℃): Conventional transportation: roller speed 8-12m / min, suitable for small-size (diameter ≤ 20mm) and low-alloy (such as Q195) bars, using continuous conveying; Intermittent transportation: For large-size (diameter ≥ 30mm) and high-carbon steel (such as 65Mn) bars, pause for 1-2s every 2-3m of transportation, and use roller air cooling to assist in cooling (wind speed 3-5m / s) to prevent thermal deformation. The pause interval is corrected through feedback from a thermal imager (temperature measurement accuracy ±2℃).

[0011] Preferably, the S302 pre-stacking shaping process: Before the bars reach the stacking area, they are straightened online via a shaping roller conveyor (with 3 sets of straightening wheels, spaced 2m apart); The pressure of the straightening wheel is adjusted according to the diameter of the bar (5-8kN for a diameter of 10mm, 20-30kN for a diameter of 50mm); Laser distance measurement (accuracy ±0.5mm) is used to monitor the straightness of the bars. When the deviation is greater than 0.3mm / m, the pressure of the correction wheel is automatically increased (+2kN each time) until the straightness is ≤0.2mm / m, ensuring neat stacking and subsequent processing accuracy.

[0012] Preferably, the S401 online quality monitoring: Arrange at the entrance of the stacking area: an ultrasonic flaw detector (detection accuracy 0.5mm defect) to scan the internal defects of the bars (such as cracks, looseness), and trigger sorting when the defect length is greater than 5mm; Hardness tester (Brinell hardness tester, indenter diameter 5mm, test force 750kgf), randomly inspect one bar out of every 10 bars, test the hardness of the head, middle and tail. If the deviation from the target hardness (such as HRB400 requires 160-220HB) is greater than ±10HB, it will be marked for re-inspection.

[0013] Preferably, the S402 process is iteratively optimized: Collect full-process data (cooling curves, transportation parameters, quality inspection results) every month and use machine learning algorithms (random forest model, feature dimensions ≥ 20) for correlation analysis: If the qualified rate of finished products of a certain type of steel (such as 45# steel) is less than 98%, reverse the cooling rate and transportation pause interval parameters, optimize the process curve (such as adjusting the cooling rate of the quenching zone ±5℃ / s); The temperature-performance correlation model is updated quarterly to incorporate data on new steel grades and specifications to ensure that the cooling and transportation process continues to adapt to production needs.

[0014] (3) Beneficial effects Compared with the prior art, the present invention provides a method for online cooling and transportation of rolled bars, which has the following beneficial effects: 1. This post-rolling online cooling and transportation method for bars achieves precise temperature control and quality improvement through segmented cooling synergy: the cooling channel is divided into three zones: rapid cooling, slow cooling, and uniform temperature. Combined with infrared temperature measurement and real-time thermocouple monitoring, the cooling intensity (aerosol nozzle opening, cooling water flow rate, and air-water ratio) is dynamically adjusted for different steel grades (e.g., HRB400 requires rapid grain growth suppression, adopting a cooling rate of 20-30°C / s; 65Mn requires controlling martensite formation, adjusting the slow cooling zone rate to 5-10°C / s). This ensures a cooling curve conformity of ≥95%, improves phase transformation uniformity, effectively addresses grain growth and internal stress concentration issues, reduces mechanical property fluctuations to ±5%, and stabilizes the product qualification rate at over 98%, significantly enhancing the adaptability of specialty steel bars to the high-end market. Intelligent deviation correction: When the temperature deviation in a certain control area is greater than ±10°C, the system automatically triggers nozzle group compensation and roller speed fine-tuning to correct cooling deviations in real time. For example, when the temperature in the rapid cooling zone is too high, the opening of the standby nozzle is increased to 30-50%, quickly lowering the temperature to ensure the stability of the cooling process and reduce the incidence of defects (such as cracks and loose structure) caused by uneven cooling. The proportion of bars with defect length greater than 5mm has been reduced from more than 5% in the traditional mode to less than 1%.

[0015] 2. This solution realizes transportation coordination and efficiency optimization through online cooling and transportation processing of the bars after rolling. It also features intelligent transportation adaptation: it automatically switches the transportation mode according to the bar specifications and the temperature after cooling. For large-sized and high-carbon steel bars, intermittent transportation (conveying 2-3m and pausing for 1-2s) is adopted. This is combined with roller air cooling (wind speed 3-5m / s) to keep the thermal deformation rate ≤0.5%. Compared with the traditional continuous transportation mode, the cost of the subsequent straightening process is reduced. 30%; small-sized and low-alloy bars adopt continuous conveying to match the cooling rhythm, shortening the production cycle by 15%-20% and improving the overall throughput of the production line; Upgraded pre-stacking shaping: Real-time monitoring of bar straightness is achieved through laser ranging (accuracy ±0.5mm), and dynamic adjustment of straightening wheel pressure (5-8kN for bars with a diameter of 10mm, 20-30kN for bars with a diameter of 50mm) to ensure straightness ≤0.2mm / m. This improves stacking neatness, increases storage space utilization by 10%, and provides more stable blanks for subsequent machining, reducing cutting tool wear and machining errors. DETAILED DESCRIPTION

[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, those skilled in the art who do not make original embodiments shall fall within the scope of protection of the present invention.

[0017] This solution provides a technical solution, specifically, a method for online cooling and transportation of bar material after rolling, including the following processing methods: S1 cooling front section: gradient temperature control preparation (0-10s after rolling): S101 Waste Heat Collection and Analysis: An infrared thermometer (accuracy ±1°C, sampling frequency 50Hz) installed at the mill exit collects the surface temperature of freshly rolled bars in real time (target range 850-950°C). Using an edge computing module and historical rolling data (steel grade, rolling speed, and finished product specifications), a temperature-performance correlation model is established to predict the phase transformation process at the bar's current temperature, providing a basis for cooling parameters. S102 cooling channel pre-adjustment: Before the bar enters the cooling section, the system automatically adjusts the cooling channel based on the temperature prediction results: The mist cooling nozzle opening (adjustable range 0-100%, accuracy ±5%) controls the mixing ratio of compressed air and cooling water (adjustable air-water ratio 10:1-50:1), and presets the initial cooling intensity for different steel grades (such as HRB400, which requires rapid cooling to inhibit grain growth). The roller conveyor speed (5-15m / min stepless speed regulation) matches the bar length (6-12m) with the cooling rhythm to ensure that the entire length of the bar is evenly cooled; S2 cooling middle section: segmented precision cooling (10-60s after rolling): S201 multi-zone cooling coordinated control: The cooling channel is divided into three control zones (rapid cooling zone, slow cooling zone, and uniform temperature zone), and each control zone is equipped with an independent temperature closed-loop control system: Rapid cooling zone (Zone 1, length 3-5m): High-pressure atomization cooling (pressure 0.8-1.2MPa) is adopted, and the cooling water flow rate (20-50m 3 / h), quickly reduce the surface temperature of the bar from 800-900℃ to 650-700℃, and control the cooling rate at 20-30℃ / s to trigger the austenite to ferrite / pearlite phase transformation; Slow cooling zone (Zone 2, length 4-6m): switch to low-pressure spray cooling (pressure 0.2-0.5MPa), and adjust the flow rate to 10-30m 3 / h, the cooling rate is reduced to 5-10℃ / s to ensure phase change uniformity and avoid internal stress; Temperature equalization zone (Zone 3, length 2-4m): Active cooling is turned off, and the residual heat inside the bar is used for self-tempering. The core temperature is monitored in real time by thermocouples (arranged at a spacing of 1.5m). When the temperature difference between the surface and the core is ≤50°C, the temperature equalization is determined to be complete and the bar enters the transportation stage; S202 intelligent deviation correction: If the temperature monitoring value of a control area deviates from the set value by more than ±10°C, the system will automatically trigger: Dynamic compensation of nozzle groups (if the temperature in the quenching zone is too high, add 2-4 groups of spare nozzles to increase the opening to 30-50%); Fine adjustment of roller speed (speed adjustment of ±0.5m / min when the deviation is 10-20°C) to ensure that the cooling curve fits the target process (e.g. the error of Q235 steel cooling curve is ≤5%); S3 transport section: coordinated scheduling and anti-deformation treatment (60s after cooling to finished product stacking): S301 transport roller intelligent adaptation: The cooled bars enter the transport roller. The system automatically selects the transport mode based on the bar specifications (diameter 10-50mm, length 6-12m) and the temperature after cooling (≤400℃): Conventional transportation: roller speed 8-12m / min, suitable for small-size (diameter ≤ 20mm) and low-alloy (such as Q195) bars, using continuous conveying; Intermittent transportation: For large-size (diameter ≥ 30mm) and high-carbon steel (such as 65Mn) bars, pause for 1-2 seconds every 2-3m of transportation, using roller air cooling (wind speed 3-5m / s) to assist in cooling and prevent thermal deformation. The pause interval is corrected through feedback from a thermal imager (temperature measurement accuracy ±2℃); S302 shaping treatment before stacking: Before the bars reach the stacking area, they are straightened online via a shaping roller conveyor (with 3 sets of straightening wheels, spaced 2m apart); The pressure of the straightening wheel is adjusted according to the diameter of the bar (5-8kN for a diameter of 10mm, 20-30kN for a diameter of 50mm); Laser distance measurement (accuracy ±0.5mm) is used to monitor the straightness of the bars. When the deviation is greater than 0.3mm / m, the pressure of the correction wheel is automatically increased (+2kN each time) until the straightness is ≤0.2mm / m, ensuring neat stacking and subsequent processing accuracy. S4 quality feedback and process iteration (full process closed loop): S401 online quality monitoring: Arrange at the entrance of the stacking area: an ultrasonic flaw detector (detection accuracy 0.5mm defect) to scan the internal defects of the bars (such as cracks, looseness), and trigger sorting when the defect length is greater than 5mm; Hardness tester (Brinell hardness tester, indenter diameter 5mm, test force 750kgf), randomly inspect one bar out of every 10 bars, and test the hardness of the head, middle and tail. If the deviation from the target hardness (such as HRB400 requirement of 160-220HB) is greater than ±10HB, it will be marked as pending re-testing; S402 process iterative optimization: Collect full-process data (cooling curves, transportation parameters, quality inspection results) every month and use machine learning algorithms (random forest model, feature dimensions ≥ 20) for correlation analysis: If the qualified rate of finished products of a certain type of steel (such as 45# steel) is less than 98%, reverse the cooling rate and transportation pause interval parameters, optimize the process curve (such as adjusting the cooling rate in the quenching zone ±5℃ / s); Update the temperature-performance correlation model quarterly to incorporate data on new steel grades and specifications to ensure the cooling and transportation process continues to adapt to production needs; Furthermore, this solution achieves precise temperature control and quality improvement through segmented cooling synergy: the cooling channel is divided into three zones: rapid cooling, slow cooling, and uniform temperature. Combined with infrared temperature measurement and real-time thermocouple monitoring, the cooling intensity (aerosol nozzle opening, cooling water flow rate, and air-water ratio) is dynamically adjusted for different steel grades (for example, HRB400 requires rapid grain growth suppression, adopting a cooling rate of 20-30°C / s; 65Mn requires controlling martensite formation, adjusting the slow cooling zone rate to 5-10°C / s). This ensures a bar cooling curve conformity rate of ≥95%, improves phase transformation uniformity, effectively addresses grain growth and internal stress concentration issues, reduces mechanical property fluctuations to ±5%, and stabilizes product qualification rates above 98%, significantly enhancing the adaptability of specialty steel bars to the high-end market. Intelligent deviation correction: When the temperature deviation in a control zone exceeds ±10°C, nozzle group compensation and roller speed fine-tuning are automatically triggered to correct cooling deviations in real time. For example, when the temperature in the quenching zone is too high, the spare nozzle opening is increased to 30-50%, quickly lowering the temperature to ensure cooling process stability and reduce the incidence of defects (such as cracks and loose structure) caused by uneven cooling. The proportion of bars with defects longer than 5mm has been reduced from over 5% in the traditional model to less than 1%. Furthermore, this solution achieves transport coordination and efficiency optimization, with intelligent transport adaptation: It automatically switches transport modes based on bar specifications and post-cooling temperature. For large-sized, high-carbon steel bars, intermittent transport (conveying 2-3 meters and pausing for 1-2 seconds) is used, combined with roller air cooling (wind speed 3-5 m / s), to keep thermal deformation rates ≤ 0.5%. Compared with traditional continuous transport, the cost of subsequent straightening processes is reduced by 30%. For small-sized, low-alloy bars, continuous transport is used to match the cooling rhythm, shortening the production cycle by 15%-20%, thereby improving the overall throughput of the production line. Upgraded pre-stacking shaping: Real-time monitoring of bar straightness is achieved through laser ranging (accuracy ±0.5mm), and dynamic adjustment of straightening wheel pressure (5-8kN for bars with a diameter of 10mm, 20-30kN for bars with a diameter of 50mm) to ensure straightness ≤0.2mm / m. This improves stacking neatness, increases storage space utilization by 10%, and provides more stable blanks for subsequent machining, reducing cutting tool wear and machining errors.

[0018] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for online cooling and transportation of rolled bars, including S1 cooling front section: gradient temperature control preparation (0-10 seconds after rolling), S2 cooling middle section: segmented precision cooling (10-60 seconds after rolling), S3 transportation section: coordinated scheduling and anti-deformation treatment (60 seconds after cooling to finished product stacking), and S4 quality feedback and process iteration (full process closed loop), characterized by: The S1 cooling front section: gradient temperature control preparation (0-10s after rolling) includes S101 waste heat collection and analysis and S102 cooling channel pre-adjustment; Among them, S2 cooling middle section: segmented precise cooling (10-60s after rolling) includes S201 multi-zone cooling coordinated control and S202 intelligent deviation correction; Among them, S3 transport section: coordinated scheduling and anti-deformation treatment (60s after cooling to finished product stacking) includes S301 transport roller intelligent adaptation and S302 pre-stacking shaping treatment; Among them, S4 quality feedback and process iteration (full process closed loop) includes S401 online quality monitoring and S402 process iteration optimization.

2. The method for online cooling and transportation of rolled bar material according to claim 1, characterized in that: The S101 waste heat collection and analysis: An infrared thermometer (accuracy of ±1°C, sampling frequency of 50Hz) installed at the mill exit is used to collect the surface temperature of freshly rolled bars in real time (target range 850-950°C). Using the edge computing module, a temperature-performance correlation model is established based on historical rolling data (steel type, rolling speed, and finished product specifications) to predict the phase change process of the bars at the current temperature, providing a basis for cooling parameters.

3. The method for online cooling and transportation of rolled bar material according to claim 1, characterized in that: The S102 cooling channel pre-adjustment: Before the bar enters the cooling section, the system automatically adjusts the cooling channel based on the temperature prediction results: The mist cooling nozzle opening (adjustable range 0-100%, accuracy ±5%) controls the mixing ratio of compressed air and cooling water (adjustable air-water ratio 10:1-50:1), and presets the initial cooling intensity for different steel grades (such as HRB400, which requires rapid cooling to inhibit grain growth). The roller conveyor speed (5-15m / min stepless speed regulation) matches the bar length (6-12m) with the cooling rhythm to ensure that the entire length of the bar is evenly cooled.

4. The method for online cooling and transportation of rolled bar material according to claim 1, characterized in that: The S201 multi-zone cooling coordinated control: The cooling channel is divided into three control zones (rapid cooling zone, slow cooling zone, and uniform temperature zone), and each control zone is equipped with an independent temperature closed-loop control system: Rapid cooling zone (Zone 1, length 3-5m): Use high-pressure atomization cooling (pressure 0.8-1.2MPa), and adjust the cooling water flow rate (20-50m 3 / h), quickly reduce the surface temperature of the bar from 800-900℃ to 650-700℃, and control the cooling rate at 20-30℃ / s to trigger the austenite to ferrite / pearlite phase transformation; Slow cooling zone (Zone 2, length 4-6m): switch to low-pressure spray cooling (pressure 0.2-0.5MPa), and adjust the flow rate to 10-30m 3 / h, the cooling rate is reduced to 5-10℃ / s to ensure phase change uniformity and avoid internal stress; Temperature equalization zone (Zone 3, length 2-4m): Turn off active cooling and use the residual heat inside the bar for self-tempering. Use thermocouples (arranged at a spacing of 1.5m) to monitor the core temperature in real time. When the temperature difference between the surface and the core is ≤50℃, the temperature equalization is determined to be completed and enter the transportation stage.

5. The method for online cooling and transportation of rolled bar material according to claim 1, characterized in that: The S202 intelligent deviation correction: If the temperature monitoring value of a control area deviates from the set value by more than ±10°C, the system will automatically trigger: Dynamic compensation of nozzle groups (if the temperature in the quenching zone is too high, add 2-4 groups of spare nozzles to increase the opening to 30-50%); Fine-tune the roller speed (when the deviation is 10-20°C, the speed is adjusted by ±0.5m / min) to ensure that the cooling curve fits the target process (e.g. the error of the cooling curve of Q235 steel is ≤5%).

6. The method for online cooling and transportation of rolled bar material according to claim 1, characterized in that: The S301 transport roller intelligent adaptation: The cooled bars enter the transport roller. The system automatically selects the transport mode based on the bar specifications (diameter 10-50mm, length 6-12m) and the temperature after cooling (≤400℃): Conventional transportation: roller speed 8-12m / min, suitable for small-size (diameter ≤ 20mm) and low-alloy (such as Q195) bars, using continuous conveying; Intermittent transportation: For large-size (diameter ≥ 30mm) and high-carbon steel (such as 65Mn) bars, pause for 1-2s every 2-3m of transportation, and use roller air cooling to assist in cooling (wind speed 3-5m / s) to prevent thermal deformation. The pause interval is corrected through feedback from a thermal imager (temperature measurement accuracy ±2℃).

7. The method for online cooling and transportation of rolled bar material according to claim 1, characterized in that: The S302 pre-stacking shaping process: Before the bars reach the stacking area, they are straightened online via a shaping roller conveyor (with 3 sets of straightening wheels, spaced 2m apart); The pressure of the straightening wheel is adjusted according to the diameter of the bar (5-8kN for a diameter of 10mm, 20-30kN for a diameter of 50mm); Laser distance measurement (accuracy ±0.5mm) is used to monitor the straightness of the bars. When the deviation is greater than 0.3mm / m, the pressure of the correction wheel is automatically increased (+2kN each time) until the straightness is ≤0.2mm / m, ensuring neat stacking and subsequent processing accuracy.

8. The method for online cooling and transportation of rolled bar material according to claim 1, characterized in that: The S401 online quality monitoring: Arrange at the entrance of the stacking area: an ultrasonic flaw detector (detection accuracy 0.5mm defect) to scan the internal defects of the bars (such as cracks, looseness), and trigger sorting when the defect length is greater than 5mm; Use a hardness tester (Brinell hardness tester, indenter diameter 5mm, test force 750kgf). Randomly inspect one bar out of every 10 bars to test the hardness of the head, middle and tail. If the deviation from the target hardness (such as HRB400 requires 160-220HB) is greater than ±10HB, mark it for re-inspection.

9. The method for online cooling and transportation of rolled bar material according to claim 1, characterized in that: The S402 process is iteratively optimized: Collect full-process data (cooling curves, transportation parameters, quality inspection results) every month and use machine learning algorithms (random forest model, feature dimensions ≥ 20) for correlation analysis: If the qualified rate of finished products of a certain type of steel (such as 45# steel) is less than 98%, reverse the cooling rate and transportation pause interval parameters, optimize the process curve (such as adjusting the cooling rate in the quenching zone ±5℃ / s）； The temperature-performance correlation model is updated quarterly to incorporate data on new steel grades and specifications to ensure that the cooling and transportation process continues to adapt to production needs.