Quality control process for improving stabilizer bar round steel

Abstract

The invention relates to the technical field of ferrous metallurgy, and discloses a quality control process for improving stabilizer bar round steel, which comprises the following steps: S1, temperature control and conveying after rolling, S2, cold bed preheating and material distribution, S3, staged slow cooling control, S4, cold bed equipment parameter optimization, S5, discharging, stacking and heat preservation, and S6, quality detection and adjustment. The initial temperature difference is eliminated through cooling bed preheating (150-250 DEG C), the cooling speed is controlled through staged slow cooling (4 DEG C / min-18 DEG C / min), roller bed levelness calibration (the deviation is smaller than or equal to 0.2 mm / m) and zoned uniform air supply are combined, the steel straightness deviation is smaller than or equal to 1.5 mm / m, the total bending degree is smaller than or equal to 0.18% of the steel length, the serpentine occurrence rate is reduced to 1% or below, and the straightness reaching rate is increased. And the strict requirement of high-end parts on the straightness is completely met.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy technology, specifically to a quality control process for improving the quality of round steel for stabilizing bars. Background Technology

[0002] As a key raw material for core components of automotive suspension systems, the straightness of round spring steel directly affects the accuracy of subsequent processing and assembly, as well as the reliability of the product during service. With the automotive industry's increasing demands for lightweight and high-precision parts, the market has imposed stringent standards on the straightness of round spring steel, requiring a bend of no more than 2mm per meter and a total bend of no more than 0.2% of the steel's length.

[0003] Traditional slow cooling bed processes for spring round steel production face numerous technical bottlenecks: First, the temperature fluctuations of the steel after rolling are large, and the rough surface and uneven speed of the roller conveyor during transport easily lead to initial deformation. Second, the lack of preheating in the cooling bed causes significant thermal stress due to rapid cooling of the steel upon entry, and dense or tilted placement of the material results in uneven cooling. Third, the slow cooling process lacks phased temperature control, leading to stress concentration due to excessively rapid cooling, while deviations in the horizontality of the cooling bed roller conveyor and uneven distribution of cooling air further exacerbate serpentine bending defects. Fourth, improper timing and stacking methods after furnace exit prevent the effective release of residual stress, resulting in secondary deformation. Fifth, serpentine bending defects require multiple straightening and repair processes, which not only reduce production efficiency but also easily form a hardened layer on the surface, increasing the risk of brittle fracture during subsequent shearing and raising production costs and quality concerns. These problems seriously affect product qualification rates and market competitiveness, necessitating a precise and controllable slow cooling process to address them. Summary of the Invention

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a quality control process for improving the round steel of stabilizing bars. It has the advantages of significantly reducing serpentine defects and improving the straightness compliance rate. It solves the problem of stress concentration caused by excessively rapid cooling, as well as the problem of uneven cooling bed roller level deviation and uneven cooling air distribution, which further aggravate serpentine defects.

[0005] (II) Technical Solution To achieve the goal of significantly reducing the above-mentioned serpentine defects and improving the straightness compliance rate, the present invention provides the following technical solution: a quality control process for improving the quality of round steel bars for stabilizing bars, including S1 post-rolling temperature control and conveying, S2 preheating and material distribution on the cooling bed, S3 staged slow cooling control, S4 cooling bed equipment parameter optimization, S5 heat preservation during furnace stacking, and S6 quality inspection and adjustment. The post-rolling temperature control and conveying includes S101 final rolling temperature control, S102 conveying speed adjustment, and S103 conveying path protection. Among them, S2 cooling bed preheating and fabric application includes S201 cooling bed preheating, S202 uniform fabric application and S203 fabric angle adjustment; The S3 phased slow cooling control includes S301 first stage (insulation and slow cooling), S302 second stage (slow cooling) and S303 third stage (natural cooling). Among them, the optimization of S4 cooling bed equipment parameters includes S401 cooling air control, S402 roller conveyor operation adjustment and S403 cooling bed level calibration. Among them, S5 furnace exit stacking insulation includes S501 stacking timing, S502 stacking method and S503 stacking protection; Among them, S6 quality inspection and adjustment includes S601 online inspection, S602 process adjustment and S603 periodic maintenance.

[0006] Preferably, the final rolling temperature control in S101 is as follows: after rolling, the steel temperature is stabilized at 790℃-860℃ to avoid uneven cooling stress caused by excessively high or fluctuating final rolling temperature.

[0007] Preferably, the conveying speed adjustment in S102 is as follows: the steel is conveyed to the cooling bed via roller conveyors, and the roller conveyor speed is controlled between 0.3m / min and 0.6m / min to ensure stable conveying of the steel and reduce collisions and deformations during the conveying process; S103 Conveyor Path Protection: The roller surface is cleaned to remove sharp corners, burrs, and attachments; flexible protective pads are used at the contact points between the steel and the roller to prevent initial deformation caused by local compression.

[0008] Preferably, the S201 cooling bed preheating: before the cooling bed is put into use, hot air is used to preheat it to 150℃-250℃ to eliminate the initial temperature difference between the cooling bed body and the steel, and reduce the thermal stress caused by the sudden cooling after the steel is put into the bed.

[0009] Preferably, the uniform material distribution in S202 is achieved by using a zoned material distribution method, with the spacing between the steel pieces on the cooling bed controlled at 80mm-120mm to avoid dense stacking leading to poor local heat dissipation; the length deviation of the same batch of steel pieces is controlled within ±50mm to prevent uneven cooling caused by inconsistent lengths. S203 Fabric Angle Adjustment: When the steel enters the bed, the parallelism deviation between the steel and the axis of the cooling bed roller is ≤0.5°, and the end alignment deviation is ≤20mm, to avoid tilting and causing excessively rapid cooling on one side.

[0010] Preferably, in the first stage of S301 (heat preservation and slow cooling): after the steel is placed in the furnace, the heat preservation cover of the cooling bed is closed to maintain a slightly positive pressure atmosphere in the furnace, the temperature is maintained at 650℃-750℃, and the heat preservation time is 120min-240min, so that the internal and surface temperatures of the steel tend to be uniform. S302 Second Stage (Slow Cooling): Through the segmented temperature control system of the cooling bed, the temperature of the steel is slowly reduced to 400℃-500℃ at a rate of 4℃ / min-18℃ / min. This stage lasts for 90min-180min, gradually releasing the internal thermal stress. S303 Stage 3 (Natural Cooling): Open the insulation cover of the cooling bed, keep the furnace well ventilated, and allow the steel to cool naturally to below 150°C at room temperature to avoid stress concentration caused by forced cooling.

[0011] Preferably, the S401 cooling air control adopts zoned air supply at the upper part of the cooling bed, with the upper air pressure adjusted to 0.15MPa-0.3MPa and the lower air pressure adjusted to 0.12MPa-0.25MPa to ensure that the cooling speed of the upper and lower surfaces is consistent; the air volume in the edge area is increased by 10%-20% compared with the center area to compensate for heat loss at the edge. S402 Roller Conveyor Operation Adjustment: The cooling bed roller conveyor adopts frequency conversion speed regulation, and the running speed is matched with the steel cooling stage. In the first stage, the roller conveyor rotates intermittently (rotates for 10 seconds every 30 minutes) to avoid the steel from being in contact with the roller conveyor for a long time and causing local cooling marks. S403 Cooling Bed Level Calibration: Regularly calibrate the level of the cooling bed roller conveyor. The level deviation should be ≤0.2mm / m to prevent uneven stress on the steel caused by roller conveyor tilting, which could lead to serpentine bending.

[0012] Preferably, the stacking timing of S501 is as follows: the steel can only be removed from the cooling bed and stacked after the temperature drops below 150°C, to avoid the accumulation of internal residual heat caused by high-temperature stacking; S502 stacking method: adopt close stacking, stacking height ≤1.2m, and place 10mm-20mm thick heat insulation pads between each stack of steel to reduce the temperature difference between the inside and outside of the stack; after stacking, cover the entire stack with rock wool insulation blankets for 20h-30h to further release residual stress. S503 Stacking Protection: The stacking site should be flat with a horizontal deviation of ≤0.5mm / m to prevent steel deformation caused by tilting of the stack; steel of different specifications should be stacked separately to prevent uneven stress caused by mixing specifications.

[0013] Preferably, the S601 online inspection involves: before each batch of steel leaves the furnace, a laser straightening instrument is used to inspect the straightness. The straightness deviation is ≤1.5mm / m, and the total curvature is ≤0.18% of the steel length. Steel that exceeds the standard is separately marked and straightened at a low temperature (straightening temperature ≥550℃).

[0014] Preferably, the S602 process adjustment involves dynamically adjusting the preheating temperature, slow cooling time, and cooling air velocity of the cooling bed based on the test results. If the occurrence rate of serpentine bends exceeds 1%, the first-stage heat preservation time is extended by 20%-30%, or the second-stage cooling rate is reduced by 5%-10%. S603 Regular Maintenance: Clean the roller conveyor and vents of the cooling bed weekly, and calibrate the temperature control system and wind speed sensor monthly.

[0015] (III) Beneficial Effects Compared with the prior art, the present invention provides a process for improving the quality control of round steel for stabilizing bars, which has the following beneficial effects: 1. This improved quality control process for round steel stabilizers significantly reduces serpentine bends and improves straightness compliance: by preheating on a cooling bed (150℃-250℃) to eliminate initial temperature differences, controlling the cooling rate in stages (4℃ / min-18℃ / min), combined with roller conveyor leveling (deviation ≤0.2mm / m) and zoned uniform air supply, the straightness deviation of the steel is ≤1.5mm / m, the total curvature is ≤0.18% of the steel length, and the serpentine bend rate is reduced to below 1%, fully meeting the stringent straightness requirements of high-end components.

[0016] 2. This improved quality control process for the round steel of the stabilizing bar achieves full stress release and avoids secondary damage: the first stage of heat preservation and slow cooling (650℃-750℃, 120min-240min) and the heat preservation after stacking (20h-30h) work together to effectively release the internal stress generated during rolling and cooling, and reduce deformation caused by residual stress; at the same time, the serpentine defects are reduced, multiple straightening is not required, the formation of a surface hardening layer during the straightening process is avoided, the risk of brittle fracture during shearing is eliminated, and the service safety of the material is improved.

[0017] 3. This improved quality control process for the round steel of the stabilizing bar achieves optimized cooling uniformity and simultaneous improvement in surface and internal quality: zoned material distribution (spacing 80mm-120mm), application of flexible protective pads, and precise control of cooling air (upper air pressure 0.15MPa-0.3MPa, lower air pressure 0.12MPa-0.25MPa) ensure consistent cooling rates on the upper and lower surfaces and inner and outer areas of the steel, avoiding uneven microstructure and surface defects caused by local overheating or undercooling, and increasing the surface flaw detection pass rate to over 99%.

[0018] 4. This improved quality control process for round steel bars for stabilizing rods achieves increased production efficiency and effective cost control: reduced serpentine defects lower scrap rates and straightening process costs by over 30%; regular maintenance of the cooling bed equipment (weekly cleaning and monthly calibration) ensures process stability and avoids production interruptions due to equipment failure; optimized stacking and protective measures reduce deformation and corrosion during transportation, reducing storage losses by 15%-20% and improving overall production efficiency by 25%-30%.

[0019] 5. This improved quality control process for stabilizer bar round steel achieves strong process adaptability and outstanding quality stability: by adjusting process parameters (heating time, cooling rate) in real time through online detection, it can adapt to the production needs of spring round steel of different specifications (20mm-60mm); the process parameters are quantified and controllable throughout the process, reducing the fluctuation range of key indicators such as product dimensional accuracy and straightness by 40%, significantly improving quality stability, and meeting the large-scale and high-standard supply requirements of the automotive industry. 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 solution provides a technical approach, specifically a quality control process for improving the quality of round steel bars used as stabilizers, comprising the following steps: S1 Temperature control and conveying after rolling: S101 Final rolling temperature control: After rolling, the steel temperature is stabilized at 790℃-860℃ to avoid uneven cooling stress caused by excessively high or fluctuating final rolling temperature. S102 Conveying Speed ​​Adjustment: The steel is conveyed to the cooling bed via roller conveyors. The roller conveyor speed is controlled between 0.3m / min and 0.6m / min to ensure smooth conveying of the steel and reduce collisions and deformations during the conveying process. S103 Conveyor Path Protection: The roller surface is cleaned to remove sharp corners, burrs, and attachments; flexible protective pads are used at the contact points between the steel and the roller to prevent initial deformation caused by local compression; S2 Cool Bed Preheating and Fabric Preparation: S201 Cold Bed Preheating: Before the cold bed is put into use, it is preheated to 150℃-250℃ with hot air to eliminate the initial temperature difference between the cold bed body and the steel, and reduce the thermal stress caused by the sudden cooling of the steel after it is put into the bed. S202 Uniform Material Distribution: A zoned material distribution method is adopted, and the spacing between steel pieces on the cooling bed is controlled at 80mm-120mm to avoid dense stacking that could lead to poor local heat dissipation; the length deviation of steel pieces in the same batch is controlled within ±50mm to prevent uneven cooling caused by inconsistent lengths. S203 Fabric Angle Adjustment: When the steel enters the cooling bed, the parallelism deviation between the steel and the axis of the cooling bed roller is ≤0.5°, and the end alignment deviation is ≤20mm, to avoid tilting and causing excessively rapid cooling on one side; S3 phased slow cooling control: S301 First Stage (Insulation and Slow Cooling): After the steel is placed in the furnace, the insulation cover of the cooling bed is closed to maintain a slightly positive pressure atmosphere inside the furnace. The temperature is maintained at 650℃-750℃, and the insulation time is 120min-240min to make the internal and surface temperatures of the steel more uniform. S302 Second Stage (Slow Cooling): Through the segmented temperature control system of the cooling bed, the temperature of the steel is slowly reduced to 400℃-500℃ at a rate of 4℃ / min-18℃ / min. This stage lasts for 90min-180min, gradually releasing the internal thermal stress. S303 Stage 3 (Natural Cooling): Open the insulation cover of the cooling bed, keep the furnace well ventilated, and allow the steel to cool naturally to below 150°C at room temperature to avoid stress concentration caused by forced cooling; S4 cooling bed equipment parameter optimization: S401 Cooling Air Control: The upper part of the cooling bed adopts zoned air supply, with the upper air pressure adjusted to 0.15MPa-0.3MPa and the lower air pressure adjusted to 0.12MPa-0.25MPa to ensure consistent cooling speed on the upper and lower surfaces; the air volume in the edge area is increased by 10%-20% compared to the center area to compensate for heat loss at the edge. S402 Roller Conveyor Operation Adjustment: The cooling bed roller conveyor adopts frequency conversion speed regulation, and the running speed is matched with the steel cooling stage. In the first stage, the roller conveyor rotates intermittently (rotates for 10 seconds every 30 minutes) to avoid the steel from being in contact with the roller conveyor for a long time and causing local cooling marks. S403 Cooling Bed Levelness Calibration: Regularly calibrate the levelness of the cooling bed roller conveyor. The level deviation should be ≤0.2mm / m to prevent uneven stress on the steel caused by roller conveyor tilting, which could lead to serpentine bending. S5 furnace exit stacking insulation: S501 Stacking Timing: The steel can only be removed from the cooling bed and stacked after the temperature drops below 150℃ to avoid the accumulation of internal residual heat caused by high-temperature stacking; S502 stacking method: adopt close stacking, stacking height ≤1.2m, and place 10mm-20mm thick heat insulation pads between each stack of steel to reduce the temperature difference between the inside and outside of the stack; after stacking, cover the entire stack with rock wool insulation blankets for 20h-30h to further release residual stress. S503 Stacking Protection: The stacking site should be flat with a horizontal deviation of ≤0.5mm / m to prevent steel deformation caused by tilting; steel of different specifications should be stacked separately to prevent uneven stress caused by mixing specifications. S6 Quality Inspection and Adjustment: S601 Online Inspection: Before each batch of steel leaves the furnace, a laser straightening instrument is used to check the straightness. The straightness deviation is ≤1.5mm / m, and the total curvature is ≤0.18% of the steel length. Steel that exceeds the standard is marked separately and straightened at a low temperature (straightening temperature ≥550℃). S602 Process Adjustment: Based on the test results, dynamically adjust the preheating temperature of the cooling bed, the slow cooling time, and the cooling air velocity. If the occurrence rate of serpentine bends exceeds 1%, extend the first-stage heat preservation time by 20%-30%, or reduce the second-stage cooling rate by 5%-10%. S603 Regular maintenance: Clean the roller conveyor and vents of the cooling bed once a week, and calibrate the temperature control system and wind speed sensor once a month to ensure accurate and stable equipment operating parameters; Furthermore, this process significantly reduces serpentine defects and improves the straightness compliance rate: by preheating the cooling bed (150℃-250℃) to eliminate the initial temperature difference, controlling the cooling rate in stages (4℃ / min-18℃ / min), combined with roller level calibration (deviation ≤0.2mm / m) and zoned uniform air supply, the straightness deviation of the steel is ≤1.5mm / m, the total curvature is ≤0.18% of the steel length, and the serpentine occurrence rate is reduced to below 1%, fully meeting the stringent straightness requirements of high-end components; Furthermore, this process achieves full stress release and avoids secondary damage: the first-stage heat preservation and slow cooling (650℃-750℃, 120min-240min) and the heat preservation after stacking (20h-30h) work together to effectively release the internal stress generated during rolling and cooling, and reduce deformation caused by residual stress; at the same time, the serpentine defects are reduced, multiple straightening is not required, the formation of a surface hardening layer during the straightening process is avoided, the risk of brittle fracture during shearing is eliminated, and the service safety of the material is improved; Furthermore, this process optimizes cooling uniformity and simultaneously improves surface and internal quality: zoned material distribution (spacing 80mm-120mm), application of flexible protective pads, and precise control of cooling air (upper air pressure 0.15MPa-0.3MPa, lower air pressure 0.12MPa-0.25MPa) ensure consistent cooling rates on the upper and lower surfaces and inner and outer areas of the steel, avoiding uneven microstructure and surface defects caused by local overheating or overcooling, and increasing the surface flaw detection pass rate to over 99%. Furthermore, this process achieves improved production efficiency and effective cost control: reduced serpentine defects lower scrap rates and straightening process costs by over 30%; regular maintenance of the cooling bed equipment (weekly cleaning and monthly calibration) ensures process stability and avoids production interruptions due to equipment failure; optimized stacking and protective measures reduce deformation and corrosion during transportation, reducing storage losses by 15%-20% and improving overall production efficiency by 25%-30%. Furthermore, this process achieves strong process adaptability and outstanding quality stability: by adjusting process parameters (heating time, cooling rate) in real time through online detection, it can adapt to the production needs of spring round steel of different specifications (20mm-60mm); the process parameters are quantified and controllable throughout the process, which reduces the fluctuation range of key indicators such as product dimensional accuracy and straightness by 40%, significantly improves quality stability, and meets the large-scale and high-standard supply requirements of the automotive industry.

[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 quality control process for improving the quality of round steel bars used as stabilizers, comprising: S1 post-rolling temperature control and conveying; S2 preheating and material distribution on the cooling bed; S3 staged slow cooling control; S4 cooling bed equipment parameter optimization; S5 heat preservation during furnace exit stacking; and S6 quality inspection and adjustment, characterized in that: The S1 post-rolling temperature control and conveying includes S101 final rolling temperature control, S102 conveying speed adjustment and S103 conveying path protection. Among them, S2 cooling bed preheating and fabric application includes S201 cooling bed preheating, S202 uniform fabric application and S203 fabric angle adjustment; The S3 phased slow cooling control includes S301 first stage (insulation and slow cooling), S302 second stage (slow cooling) and S303 third stage (natural cooling). Among them, the optimization of S4 cooling bed equipment parameters includes S401 cooling air control, S402 roller conveyor operation adjustment and S403 cooling bed level calibration. Among them, S5 furnace exit stacking insulation includes S501 stacking timing, S502 stacking method and S503 stacking protection; Among them, S6 quality inspection and adjustment includes S601 online inspection, S602 process adjustment and S603 periodic maintenance.

2. The quality control process for improving the round steel of the stabilizer bar according to claim 1, characterized in that: The S101 final rolling temperature control: After rolling, the steel temperature is stabilized at 790℃-860℃ to avoid uneven cooling stress caused by excessively high or fluctuating final rolling temperatures.

3. The quality control process for improving the round steel of the stabilizer bar according to claim 1, characterized in that: The S102 conveying speed adjustment: The steel is conveyed to the cooling bed via roller conveyors, and the roller conveyor speed is controlled between 0.3m / min and 0.6m / min to ensure stable conveying of the steel and reduce collisions and deformations during the conveying process; S103 Conveyor Path Protection: The roller surface is cleaned to remove sharp corners, burrs, and attachments; flexible protective pads are used at the contact points between the steel and the roller to prevent initial deformation caused by local compression.

4. The quality control process for improving the round steel of the stabilizer bar according to claim 1, characterized in that: The S201 cooling bed preheating: Before the cooling bed is put into use, it is preheated to 150℃-250℃ with hot air to eliminate the initial temperature difference between the cooling bed body and the steel, and reduce the thermal stress caused by the sudden cooling after the steel is put into the bed.

5. The quality control process for improving the round steel of the stabilizer bar according to claim 1, characterized in that: The S202 uniform material distribution method adopts a zoned material distribution method, and the spacing between the steel pieces on the cooling bed is controlled at 80mm-120mm to avoid dense stacking that would lead to poor local heat dissipation; the length deviation of the same batch of steel pieces is controlled within ±50mm to prevent uneven cooling caused by different lengths. S203 Fabric Angle Adjustment: When the steel enters the bed, the parallelism deviation between the steel and the axis of the cooling bed roller is ≤0.5°, and the end alignment deviation is ≤20mm, to avoid tilting and causing excessively rapid cooling on one side.

6. The quality control process for improving the round steel of the stabilizer bar according to claim 1, characterized in that: The first stage of S301 (heat preservation and slow cooling): After the steel is put into the furnace, the heat preservation cover of the cooling bed is closed to maintain a slightly positive pressure atmosphere in the furnace. The temperature is maintained at 650℃-750℃ and the heat preservation time is 120min-240min, so that the internal and surface temperatures of the steel tend to be uniform. S302 Second Stage (Slow Cooling): Through the segmented temperature control system of the cooling bed, the temperature of the steel is slowly reduced to 400℃-500℃ at a rate of 4℃ / min-18℃ / min. This stage lasts for 90min-180min, gradually releasing the internal thermal stress. S303 Stage 3 (Natural Cooling): Open the insulation cover of the cooling bed, keep the furnace well ventilated, and allow the steel to cool naturally to below 150°C at room temperature to avoid stress concentration caused by forced cooling.

7. The quality control process for improving the round steel of the stabilizer bar according to claim 1, characterized in that: The S401 cooling air control: The upper part of the cooling bed adopts zoned air supply, with the upper air pressure adjusted to 0.15MPa-0.3MPa and the lower air pressure adjusted to 0.12MPa-0.25MPa to ensure that the cooling speed of the upper and lower surfaces is consistent; the air volume in the edge area is increased by 10%-20% compared with the center area to compensate for heat loss at the edge. S402 Roller Conveyor Operation Adjustment: The cooling bed roller conveyor adopts frequency conversion speed regulation, and the running speed is matched with the steel cooling stage. In the first stage, the roller conveyor rotates intermittently (rotates for 10 seconds every 30 minutes) to avoid the steel from being in contact with the roller conveyor for a long time and causing local cooling marks. S403 Cooling Bed Level Calibration: Regularly calibrate the level of the cooling bed roller conveyor. The level deviation should be ≤0.2mm / m to prevent uneven stress on the steel caused by roller conveyor tilting, which could lead to serpentine bending.

8. The quality control process for improving the round steel of the stabilizer bar according to claim 1, characterized in that: The timing for stacking S501: The steel can only be removed from the cooling bed and stacked after the temperature drops below 150℃, to avoid the accumulation of internal residual heat caused by high-temperature stacking; S502 stacking method: adopt close stacking, stacking height ≤1.2m, and place 10mm-20mm thick heat insulation pads between each stack of steel to reduce the temperature difference between the inside and outside of the stack; after stacking, cover the entire stack with rock wool insulation blankets for 20h-30h to further release residual stress. S503 Stacking Protection: The stacking site should be flat with a horizontal deviation of ≤0.5mm / m to prevent steel deformation caused by tilting of the stack; steel of different specifications should be stacked separately to prevent uneven stress caused by mixing specifications.

9. The quality control process for improving the round steel of the stabilizer bar according to claim 1, characterized in that: The S601 online inspection: Before each batch of steel leaves the furnace, a laser straightening instrument is used to check the straightness. The straightness deviation is ≤1.5mm / m, and the total curvature is ≤0.18% of the steel length. Steel that exceeds the standard is marked separately and straightened at a low temperature (straightening temperature ≥550℃).

10. The quality control process for improving the round steel of the stabilizer bar according to claim 1, characterized in that: The S602 process adjustment: Based on the test results, dynamically adjust the preheating temperature of the cooling bed, the slow cooling time, and the cooling air velocity. If the occurrence rate of serpentine bends exceeds 1%, extend the first-stage heat preservation time by 20%-30%, or reduce the second-stage cooling rate by 5%-10%. S603 Regular Maintenance: Clean the roller conveyor and vents of the cooling bed weekly, and calibrate the temperature control system and wind speed sensor monthly.