Full-process production method for rolling high-performance bar with diameter phi of 36 mm

Abstract

The invention relates to the technical field of steel and iron material rolling, and particularly discloses a full-process production method for rolling a high-performance bar with the diameter phi of 36 mm. Three-stage temperature dynamic regulation and control are conducted, specifically, a steel billet with a configured component system is fed into a heating furnace, and a rough rolling-intermediate rolling-finish rolling dynamic temperature control model is constructed; according to the multi-specification compatible composite hole pattern, a flat ellipse-round-square composite hole pattern sequence is adopted; differentiated intelligent cooling is conducted, specifically, a controlled cooling process database is built, and cooling schemes are formulated according to different steel grade components; multi-dimensional online quality detection: laser diameter measurement and AI metallographic detection are integrated, a laser diameter measurement instrument is additionally mounted at a finish rolling outlet, and a rapid metallographic detector is deployed at a cooling bed outlet; loop parameter control: establishing a loop height dynamic compensation model, and solidifying a loop control program through a PLC system; the product comprehensively meets the requirement of high-end equipment manufacturing for high-performance bars, the equipment idleness and production cost are greatly reduced, the production stability is greatly improved, and the production efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of steel material rolling technology, specifically to a complete production method for rolling high-performance bars with a diameter of Φ36mm. Background Technology

[0002] Currently, the rolling process for Φ36mm diameter bars largely follows traditional bar rolling techniques and lacks a dedicated optimization system: composition design relies on empirical values ​​from similar specifications, and the microalloying element ratios lack systematic optimization; temperature control is a crude, fixed-range adjustment without a dynamic feedback mechanism; the pass system follows a "one specification, one pass" principle, lacking compatibility with similar specifications, and the finished pass and K2 stand pass designs are not adapted to the characteristics of Φ36mm; the cooling process uses a single rate, lacking differentiated and coordinated control; quality inspection relies mainly on offline sampling, lacking real-time monitoring; and looper control depends on manual experience, without standardized parameters and solidified processes. Specifically, the following defects exist:

[0003] 1. Product performance is substandard: Mechanical properties (yield strength 380-420MPa, tensile strength 520-550MPa) do not meet high-end requirements, transverse rib filling is 80%-85%, there are problems such as missing material, collapsed shoulders and surface scratches, dimensional tolerance deviation is ±0.4-0.6mm, grain size is 6-7 grade, and the dispersion of microstructure and properties is high.

[0004] 2. Poor process compatibility: Switching between specifications requires replacing the rolls, which takes more than 2 hours. The debugging cycle is long, there is a lot of waste, and the steel throughput of the rolling trough is only 800 tons / trough, resulting in high costs.

[0005] 3. Insufficient production stability: Looping parameters fluctuate greatly, steel stacking rate is 1.2%, temperature and cooling control are out of control, and the risk of steel breakage and cracking is high.

[0006] 4. Lagging quality control: The offline testing cycle is long, there is no closed-loop control mechanism, the first pass rate of products is only 85%-90%, and the waste of defective products is serious.

[0007] 5. Low level of green and low carbon emissions: High energy consumption per unit of product, PM2.5 emissions do not meet standards, and do not conform to environmental protection policy guidelines.

[0008] Therefore, it is necessary to explore a complete production process for rolling high-performance bars with a diameter of Φ36mm to solve the problems of poor production compatibility and high energy consumption in the existing Φ36mm bar rolling process. Summary of the Invention

[0009] To address the problems existing in the prior art, the purpose of this invention is to provide a complete production method for rolling high-performance bars with a diameter of Φ36mm, which is suitable for the large-scale production of high-strength and high-precision bars required in high-end equipment manufacturing, high-end construction and other fields.

[0010] The technical solution adopted by this invention to solve its technical problem is: a complete production method for rolling high-performance bars with a diameter of Φ36mm, comprising the following steps:

[0011] S1. Alloy composition configuration: The chemical composition of the billet is based on the following mass percentage system: Mn: 1.2%-1.5%, Si: 0.4%-0.6%, V: 0.02%-0.06%, Nb: 0.02%-0.06%.

[0012] S2. Three-stage dynamic temperature control: The steel billet with the prepared composition system is sent into the heating furnace to construct a dynamic temperature control model of "roughing-intermediate rolling-finishing".

[0013] S3, Multi-specification compatible composite hole pattern: adopts a "flat ellipse-round-square" composite hole pattern sequence;

[0014] S4. Differentiated Intelligent Cooling: Establish a controlled cooling process database and develop cooling solutions for different steel compositions;

[0015] S5. Multi-dimensional online quality inspection: Integrating laser diameter measurement and AI metallographic inspection, a laser diameter measuring instrument is installed at the finish rolling mill exit, and a rapid metallographic inspection instrument is deployed at the cooling bed exit;

[0016] S6. Looping parameter control: Establish a dynamic compensation model for the looping height and solidify the looping control program through a PLC system;

[0017] S7. Finished product cutting and inspection: Finished products are cut and inspected before being put into storage.

[0018] Specifically, in step S2, the heating furnace is heated to 1050-1100℃, that is, the roughing rolling temperature is stabilized at 1050-1100℃. The heating furnace power is dynamically adjusted in real time by an infrared thermometer. The intermediate rolling mill implements a gradient cooling strategy, and the temperature difference between each stand is controlled at 30-50℃ to suppress abnormal grain growth. The finishing rolling mill locks the temperature at 820-860℃, and the cooling water flow rate is dynamically adjusted in combination with the rolling speed to control the temperature uniformity error of the rolling mill to ≤5℃.

[0019] Specifically, in step S2, the composite pass sequence is based on the existing Φ32mm pass. The width-to-height ratio of the roughing pass is controlled at 1.8-2.2. The finishing pass adopts a double arc transition with a top arc radius of 0.8mm for the transverse rib. The inlet and outlet leads of the finishing pass are set at an inclination angle of 5-8°. The flat elliptical pass with a width-to-height ratio of 2.0 in stand K2 is used for Φ32mm and Φ36mm specifications to share a pass system.

[0020] Specifically, the cooling scheme in step S4 is as follows: the cooling rate of the front section of the cooling bed is controlled at 15-20℃ / s, and the rate of the rear section is reduced to 5-8℃ / s to release internal stress; the final cooling temperature is controlled at 600-650℃ with a fluctuation range of ≤10℃ and a pearlite + ferrite ratio of ≥95% by linking the roller speed and cooling water volume through the PLC control system.

[0021] Specifically, in step S5, the laser diameter measuring instrument has a measurement accuracy of ±0.03mm, a data transmission delay of ≤0.5s, and collects dimensional data in real time; the metallographic rapid testing instrument completes the grain size and structure determination within 10 seconds, with a grain size ≥8.

[0022] Specifically, the looper height dynamic compensation model in step S6 is as follows: the height error is set to ≤ ±5mm; the looper start-up response time is ≤ 0.3s; the looper drop position accuracy is ≤ 2mm; and the rolling rhythm interval of the rolling line is controlled within 5 seconds.

[0023] Specifically, in step S7, the shearing is controlled by the No. 2 shearing head according to the thermal detection signal, and the deviation is controlled within 25cm; the finished product is sampled for mechanical properties, dimensional accuracy, and metallographic structure, and is put into storage after passing the inspection.

[0024] The present invention has the following beneficial effects:

[0025] The whole-process production method for rolling high-performance bars with a diameter of Φ36mm designed in this invention significantly improves product performance. Through alloy composition optimization and process synergistic control, the product yield strength is ≥425MPa, tensile strength is ≥560MPa, transverse rib filling degree is ≥98%, grain size is ≥8 grade, and dimensional tolerance deviation is ≤±0.3mm, fully meeting the requirements of high-end equipment manufacturing for high-performance bars.

[0026] This invention presents a breakthrough in the process compatibility of the whole-process production method for rolling high-performance bars with a diameter of Φ36mm. It innovatively designs a multi-specification shared roll system, realizing seamless switching between Φ32mm and Φ36mm specifications. The switching time is reduced by 75%, the debugging cycle is reduced by 40%, and the debugging cost per ton of steel is reduced by 15 yuan, significantly reducing equipment idle time and production costs.

[0027] The whole-process production method for rolling high-performance bars with a diameter of Φ36mm designed in this invention has greatly improved the production stability. The application of precise solidification of looper parameters and intelligent cooling control technology reduces the steel accumulation rate to below 0.1% and increases the dimensional tolerance qualification rate of rolled parts to 99.5%, significantly reducing production interruptions and waste generation.

[0028] The invention presents an intelligent quality control system for the entire production process of rolling high-performance bars with a diameter of Φ36mm. The multi-dimensional online monitoring system enables real-time early warning and handling of quality problems, achieving a first-pass yield of ≥98%, reducing offline testing costs and losses from defective products, and improving production efficiency.

[0029] The present invention presents a complete production method for rolling high-performance bars with a diameter of Φ36mm. The process optimization reduces energy consumption and waste emissions. Combined with efficient dust removal technology, PM2.5 emissions are reduced by 30%, which is in line with the national green manufacturing and carbon neutrality policy. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be described clearly, completely, and in further detail below. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] A complete production method for rolling high-performance bars with a diameter of Φ36mm includes the following steps:

[0032] 1. Alloy Composition: The chemical composition of the steel billet is precisely proportioned according to the following mass percentages: Mn: 1.2%-1.5%, Si: 0.4%-0.6%, V: 0.02%-0.06%, Nb: 0.02%-0.06%. The optimal composition ratio is determined through thermal simulation tests to ensure that the mechanical properties meet the standards. Multiple sets of composition ratio tests are conducted, and the correlation between composition and mechanical properties is analyzed through thermal simulation tests to determine the optimal ratio, ensuring a yield strength ≥425MPa, tensile strength ≥560MPa, and elongation after fracture ≥20%, while also ensuring machinability.

[0033] 2. Heat treatment: The steel billet with the prepared composition system is sent into the heating furnace and heated to 1050-1100℃. The heating furnace power is dynamically adjusted in real time by using an infrared thermometer to ensure that the steel billet temperature is uniform.

[0034] 3. Rough rolling process: A composite pass sequence of "flat ellipse-round-square" is adopted, and the width-to-height ratio of the rough rolling pass is controlled at 1.8-2.2. A multi-specification compatible pass system is used for rolling to reduce the problem of uneven workpiece width.

[0035] 4. Intermediate Rolling Process: Implement a gradient cooling strategy, controlling the temperature difference between each stand to 30-50℃ to suppress abnormal grain growth. Based on big data analysis, extract the optimal parameter combination and solidify the looper control program through a PLC system: establish a dynamic compensation model for looper height, setting the height error to ≤±5mm; looper start-up response time ≤0.3s, and looper drop-off position accuracy ≤2mm; control the rolling rhythm interval within 5 seconds to reduce the risk of steel accumulation and improve production continuity.

[0036] 5. Finishing Rolling Process: The K2 stand uses a flat elliptical pass with a width-to-height ratio of 2.0. The finishing rolling temperature is locked at 820-860℃, and the cooling water flow rate is dynamically adjusted in conjunction with the workpiece speed to ensure a temperature uniformity error of ≤5℃. The finishing pass adopts a double-arc transition design, with a 0.8mm radius of the top arc of the transverse rib and a 5-8° inclination angle for the pass inlet and outlet leads. The innovative flat elliptical pass with a width-to-height ratio of 2.0 in the K2 stand allows for the use of a single pass system for both Φ32mm and Φ36mm specifications, enabling specification switching without changing rolls, and increasing the steel throughput of the slot to 1200 tons / slot.

[0037] 6. Intelligent cooling treatment: After the rolled workpiece enters the cooling bed, the front section is rapidly cooled at a cooling rate of 15-20℃ / s, and the rear section is slowly cooled at a rate of 5-8℃ / s. The final cooling temperature is controlled at 600-650℃ with a fluctuation range of ≤10℃ by linking the roller speed and cooling water volume through the PLC control system, ensuring the stability of the metallographic structure (pearlite + ferrite ratio ≥95%).

[0038] 7. Online quality inspection: At the finishing mill exit, a laser diameter gauge (accuracy ±0.03mm) is used to collect dimensional data in real time, and at the cooling bed exit, an AI metallographic rapid inspection instrument is used to complete the grain size (≥8 grade) and microstructure determination within 10 seconds; when the data is abnormal, the system will automatically issue an early warning and adjust the process parameters accordingly to achieve closed-loop quality control.

[0039] 8. Finished product shearing and inspection: Control the No. 2 shearing head according to the heat detection signal, and keep the deviation within 25cm; conduct random inspections on the mechanical properties, dimensional accuracy and metallographic structure of the finished products, and put them into the warehouse after passing the inspection.

[0040] This invention adopts a multi-specification shared die design technology: by adjusting the width-to-height ratio of the die and the inlet and outlet lead parameters, the Φ32mm and Φ36mm die systems are compatible, and specification switching can be completed without changing the rolls.

[0041] This invention employs a high aspect ratio flat elliptical die forming technology: a flat elliptical die with an aspect ratio of 2.0 is designed in the K2 stand to increase the deformation of the rolled part in the finished die and optimize the filling effect of the transverse ribs.

[0042] This invention employs a precise parameter solidification technology for loopers: based on big data analysis, the optimal parameter combination is extracted, and the looper height and looper lifting and lowering time parameters are solidified through a PLC system to form a standardized control program.

[0043] This invention employs a multi-dimensional online monitoring technology encompassing "size, temperature, and microstructure": integrating laser diameter measurement, infrared thermometry, and rapid metallographic detection technologies to achieve real-time data transmission, anomaly warning, and process linkage adjustment.

[0044] This invention employs a precise microalloying technique: the optimal content of V and Nb microalloys is determined through thermal simulation experiments, thereby achieving synergistic optimization of mechanical and processing properties.

[0045] This invention is not limited to the above-described embodiments. Anyone should know that any structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention.

[0046] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A complete production method for rolling high-performance bars with a diameter of Φ36mm, characterized in that, Includes the following steps: S1. Alloy composition configuration: The chemical composition of the billet is based on the following mass percentage system: Mn: 1.2%-1.5%, Si: 0.4%-0.6%, V: 0.02%-0.06%, Nb: 0.02%-0.06%. S2, Three-stage dynamic temperature control: The steel billet with the prepared composition system is sent into the heating furnace to construct a dynamic temperature control model of "roughing-intermediate rolling-finishing"; S3, Multi-specification compatible composite hole pattern: adopts a "flat ellipse-round-square" composite hole pattern sequence; S4. Differentiated Intelligent Cooling: Establish a controlled cooling process database and develop cooling solutions for different steel compositions; S5. Multi-dimensional online quality inspection: Integrating laser diameter measurement and AI metallographic inspection, a laser diameter measuring instrument is installed at the finish rolling mill exit, and a rapid metallographic inspection instrument is deployed at the cooling bed exit; S6. Looping parameter control: Establish a dynamic compensation model for the looping height and solidify the looping control program through a PLC system; S7. Finished product cutting and inspection: Finished products are cut and inspected before being put into storage.

2. The complete production method for rolling high-performance bars with a diameter of Φ36mm according to claim 1, characterized in that, In step S2, the heating furnace is heated to 1050-1100℃, that is, the rough rolling start temperature is stabilized at 1050-1100℃. The heating furnace power is dynamically adjusted by real-time monitoring through an infrared thermometer. The intermediate rolling mill implements a gradient cooling strategy, with the temperature difference between each stand controlled at 30-50℃ to suppress abnormal grain growth. The finishing rolling temperature is locked at 820-860℃, and the cooling water flow rate is dynamically adjusted in combination with the rolling speed to control the temperature uniformity error of the rolled piece to ≤5℃.

3. The complete production method for rolling high-performance bars with a diameter of Φ36mm according to claim 1, characterized in that, In step S2, the composite pass sequence is based on the existing Φ32mm pass. The width-to-height ratio of the roughing pass is controlled at 1.8-2.

2. The finishing pass adopts a double arc transition with a top arc radius of 0.8mm for the transverse rib. The inlet and outlet leads of the finishing pass are set at an inclination angle of 5-8°. The flat elliptical pass with a width-to-height ratio of 2.0 in stand K2 is used for Φ32mm and Φ36mm specifications to share a pass system.

4. The complete production method for rolling high-performance bars with a diameter of Φ36mm according to claim 1, characterized in that, The cooling scheme in step S4 is as follows: the cooling rate of the front section of the cooling bed is controlled at 15-20℃ / s, and the rate of the rear section is reduced to 5-8℃ / s to release internal stress; the final cooling temperature is controlled at 600-650℃ with a fluctuation range of ≤10℃ and a pearlite + ferrite ratio of ≥95% by linking the roller speed and cooling water volume through the PLC control system.

5. The complete production method for rolling high-performance bars with a diameter of Φ36mm according to claim 1, characterized in that, In step S5, the laser diameter measuring instrument has a measurement accuracy of ±0.03mm and a data transmission delay of ≤0.5s, and collects dimensional data in real time; the metallographic rapid testing instrument completes the determination of grain size and structure within 10 seconds, with a grain size ≥8.

6. The complete production method for rolling high-performance bars with a diameter of Φ36mm according to claim 1, characterized in that, The dynamic compensation model for looper height in step S6 is as follows: the height error is set to ≤ ±5mm; the looper start-up response time is ≤0.3s; the looper drop position accuracy is ≤2mm; and the rolling rhythm interval of the rolling line is controlled within 5 seconds.

7. The complete production method for rolling high-performance bars with a diameter of Φ36mm according to claim 1, characterized in that, In step S7, the shearing is controlled by the No. 2 shearing head according to the thermal detection signal, and the deviation is controlled within 25cm; the finished product is randomly inspected for mechanical properties, dimensional accuracy, and metallographic structure, and is put into storage after passing the inspection.