16.165 m mm square billet HRB500E steel grade direct rolling method

Abstract

The invention relates to the technical field of steel rolling, and particularly discloses a 16.165 m square billet HRB500E steel grade direct rolling method, which comprises the following steps: direct rolling path planning: after a 16m steel billet is produced through continuous casting, the steel billet is directly conveyed to a rolling line for rolling through a direct rolling roller way without passing through a heating furnace; straight roller way control is conducted, specifically, a steel billet waiting position is determined through a laser detector of a 1 # continuous casting roller way R1, a hot metal detector of a 3 # straight roller way H7 and a hot metal detector of a 7 # straight roller way H6; electromagnetic heat compensation: detecting the billet by a hot metal detector of a 3 # straight roller way H7, automatically adjusting the power by an electromagnetic heat compensation device according to the billet temperature, and sending the billet to a rolling mill at a high speed through a delayed recovery straight roller way after leaving the 3 # straight roller way H7; blank positioning: arranging an image recognition system at a 1 # continuous casting roller way R1 of the heating furnace; setting rolling parameters; controlling a steel grade water tank and a nozzle; the rolling temperature is guaranteed, high-precision positioning and tracking are achieved, and production automation and stability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of steel rolling, and particularly relates to a direct rolling method for HRB500E steel grade of 16-meter 165mm square billets. Background Art

[0002] In the bar manufacturing process of steel production, for two specifications of steel billets of 165mm×165mm×12000mm and 165mm×165mm×16000mm of HRB500E steel grade, the traditional production process mainly relies on a double regenerative walking beam reheating furnace for pretreatment. In the cold charging mode, the steel billets are first placed on the loading table, and then after being screened by the two-way rejection roller table, they are conveyed to the reheating furnace by the furnace inlet roller table. In the reheating furnace, the steel billets have to go through three different heating stages, and then are gradually transferred to the furnace outlet cantilever roller table through the precise movement of the walking beam, and finally enter the rolling mill smoothly through the furnace outlet roller table to start the rolling process. In the hot charging mode, the steel billets start from the continuous casting roller table, flow through the collecting roller table, the hot charging roller table and the straightening machine in sequence for preliminary treatment and straightening, and then enter the reheating furnace through the furnace inlet roller table. The subsequent heating and rolling steps are the same as those in the cold charging mode.

[0003] In terms of direct rolling, at present, the direct rolling operation of HRB500E continuous casting billets has also been carried out to a certain extent. Usually, the initial temperature of the continuous casting billets can reach about 1050°C. However, in the subsequent production process, due to the change law of the continuous casting drawing speed at 4 m / s and a temperature drop of 0.7°C per second, during the casting process lasting about 4 minutes, the temperature of the head of the steel billet will drop significantly, with a drop of up to 168°C, resulting in the head temperature dropping to 882°C. After that, during the transportation process of the steel billets through a 174-meter direct rolling roller table, the temperature will further drop by 60°C due to heat dissipation and other factors. Finally, before entering the No. 1 rolling mill, the head temperature of the steel billets only remains at 820°C.

[0004] Serious energy and material losses: The traditional heating furnace heating process makes the oxidation and burning loss of steel billets extremely prominent, and the oxidation and burning loss rate per ton of steel is as high as 0.9%, which undoubtedly causes a large amount of waste of raw materials and greatly compresses the profit space of steel production. At the same time, the gas consumption is at a relatively high level in both the hot billet and cold billet cases. The gas consumption per ton of hot billets is about 150m 3 3, and that of cold billets is even as high as 230m 3 3 or so. This not only increases the energy cost burden of the enterprise, but also is not conducive to the enterprise achieving the energy conservation and emission reduction goals under the increasingly strict environmental protection requirements, posing a severe challenge to the sustainable development of the enterprise.

[0005] Equipment maintenance is extremely difficult: The regenerative walking beam reheating furnace has a complex structure itself. Its heating process involves multiple technical aspects such as complex heat transfer, gas combustion, and flow control. Precise regulation of numerous parameters is required to ensure normal operation. This makes the equipment maintenance work extremely cumbersome. Any malfunction in parts such as heating elements, transmission components, and control systems may cause abnormal operation of the entire reheating furnace, thereby leading to production interruption. Enterprises need to invest a large number of professional technical personnel and time in regular inspections, maintenance, and debugging, which undoubtedly increases the labor cost and time cost of enterprises and reduces production efficiency.

[0006] Poor direct rolling temperature control: In the existing direct rolling process, due to the ineffective control of the temperature drop of the billet during continuous casting and transportation, the temperature difference between the head and tail of the billet before entering the rolling mill is greater than 100°C. This large temperature difference will cause a series of problems during the rolling process. When biting the steel, the motor will bear an impact far exceeding the rated current, seriously damaging the performance and service life of the motor and the speed reducer. Frequent equipment maintenance and replacement become inevitable, increasing the equipment operation cost. Moreover, the uneven head temperature will cause inconsistent deformation of the head of the rolled piece, greatly increasing the risk of billet cracking and frequent occurrence of steel piling accidents, seriously disrupting the continuity of production, reducing the product qualification rate, causing a large amount of raw material waste and economic losses, and greatly hindering the improvement of the production efficiency of enterprises and the guarantee of product quality. Therefore, a direct rolling method for 16-meter 165mm square billet of HRB500E steel grade is designed to solve the problems of low product qualification rate and poor product quality in the existing 16-meter billet rolling. Summary of the Invention

[0007] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a direct rolling method for 16-meter 165mm square billet of HRB500E steel grade.

[0008] The technical solution adopted by the present invention to solve its technical problems is: A direct rolling method for 16-meter 165mm square billet of HRB500E steel grade, including the following steps:

[0009] 1) Direct rolling path planning: After the continuous casting produces a 16-meter billet, it is directly sent to the rolling line for rolling through the direct rolling roller table without passing through the reheating furnace.

[0010] 2) Direct rolling roller table control: Use the laser detector of the 1# continuous casting roller table R1, the hot metal detector of the 3# direct rolling roller table H7, and the hot metal detector of the 7# direct rolling roller table H6 to determine the billet waiting position.

[0011] 3) Electromagnetic supplementary heating: When the hot metal detector of the 3# direct rolling roller table H7 detects the billet, the electromagnetic supplementary heating device automatically adjusts the power according to the billet temperature. After the billet leaves the 3# direct rolling roller table H7, the direct rolling roller table resumes high-speed feeding to the rolling mill after a time delay.

[0012] 4) Blank positioning: An image recognition system is installed at the R1 of the 1# continuous casting roller table in the heating furnace;

[0013] 5) Rolling parameter setting: Control of the steel grade water tank and nozzles.

[0014] Specifically, the 16-meter billet in step 1) is quickly transferred into the direct rolling roller table through the continuous casting roller table and the gathering roller table.

[0015] Specifically, the determined billet waiting position in step 2) runs at a high speed of 4.5 m / s on the direct rolling roller table under normal conditions. The start and stop of the billet are controlled according to the subsequent billets in the waiting position, and the tapping cycle is set to prevent billet stacking.

[0016] Specifically, after the hot metal detector of the 3# direct rolling roller table H7 in step 3) detects the billet, the roller speed of the direct rolling roller table drops from 4.5 m / s to 0.4 m / s, and the electromagnetic reheating device controls the billet to reach above 920 °C with a head and tail temperature difference within 35 °C.

[0017] Specifically, the electromagnetic reheating device controls the direct rolling current not to be overloaded, the casting speed of the continuous caster shall not be lower than 3.9 m / min, the electromagnetic reheating cancels sectional heating, and the head heating time is changed from 5 seconds to 8 seconds.

[0018] Specifically, the image recognition system in step 4) uses an infrared camera. The infrared camera collects image data and transmits it to the processing station for position analysis. The image data after position analysis by the processing station and the detector signal of the 1# continuous casting roller table R1 are used by the PLC control system to accurately transport the billet to the rolling mill.

[0019] Specifically, the control of the steel grade water tank and nozzles in step 5): Remove the 2# water tank and add nozzles to the 4# water tank at the same time.

[0020] The present invention has the following beneficial effects:

[0021] The direct rolling method for 16-meter 165mm square billet of HRB500E steel grade designed by the present invention has efficient temperature control. First, to ensure that the direct rolling current of HRB500E is not overloaded, it is stipulated that the casting speed of the continuous caster shall not be lower than 3.9 m / min. The electromagnetic reheating cancels sectional heating, and the head heating time is changed from 5 seconds of HRB400E to 8 seconds. The electromagnetic reheating is integrated with intelligent temperature monitoring. When the billet reaches a specific position (such as at H7), the roller table decelerates, and the electromagnetic device adjusts the power according to the temperature, so that the billet reaches above 920 °C with a head and tail temperature difference within 35 °C, ensuring the rolling temperature and improving the product quality stability.

[0022] The direct rolling method for 16-meter 165mm square billet of HRB500E steel designed by the present invention accurately positions and tracks the billets. By combining image recognition and laser detection with intelligent algorithms, it collects and analyzes billet information at the R1 position of the 1# continuous casting roller table, and plans transportation based on the model and multi-source data after integrating the data, achieving high-precision positioning and tracking, and improving production automation and stability.

[0023] The direct rolling method for 16-meter 165mm square billet of HRB500E steel designed by the present invention synergistically optimizes rolling and cooling. It constructs an optimization model for rolling parameters and coordinates with the water tank control system, considers various factors to solve the key rolling parameters, controls the rolling mill accordingly, and precisely regulates the water tank parameters at the same time to ensure efficient rolling, qualified products, long equipment life, and cost reduction. Specific implementation mode

[0024] The technical solutions in the embodiments of the present invention will be further described clearly and completely below. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] A direct rolling method for 16-meter 165mm square billet of HRB500E steel includes the following steps:

[0026] 1. Direct rolling path planning: After the continuous casting produces 16-meter billets, without passing through the heating furnace, they are directly sent to the rolling line for rolling through the direct rolling roller table; the 16-meter billets are quickly transferred through the continuous casting roller table and the gathering roller table and enter the direct rolling roller table.

[0027] 2. Direct rolling roller table control: Use the laser detector of the 1# continuous casting roller table R1, the hot metal detector of the 3# direct rolling roller table H7, and the hot metal detector of the 7# direct rolling roller table H6 to determine the waiting position of the billets; when the waiting position of the billets is normal, the direct rolling roller table runs at a high speed of 4.5 m / s, and the start and stop of the billets are controlled according to the subsequent waiting billets, and the tapping cycle is set to prevent billet stacking.

[0028] 3. Electromagnetic supplementary heating: When the hot metal detector of the 3# direct rolling roller table H7 detects the billet, the roller speed of the direct rolling roller table drops from 4.5 m / s to 0.4 m / s, and the electromagnetic supplementary heating device automatically adjusts the power according to the billet temperature. The electromagnetic supplementary heating device controls the billet to reach above 920°C and the temperature difference between the head and the tail is within 35°C. After the billet leaves the 3# direct rolling roller table H7, it resumes the high-speed of 4.5 m / s of the direct rolling roller table and is sent to the rolling mill after a delay. Temperature monitoring: A network is formed by the hot metal detector of the 3# direct rolling roller table H7 and the hot metal detector of the 7# direct rolling roller table H6 to continuously monitor the billet temperature and transmit it to the control system for regulating the supplementary heating power and the process temperature to ensure that the billet enters the rolling mill at an appropriate temperature.

[0029] 4. Blank positioning: An image recognition system is installed at the R1 of the 1# continuous casting roller table in the heating furnace; the image recognition system uses an infrared camera, and the infrared camera collects image data and transmits it to the processing station for position analysis. After the position analysis by the processing station, the image data and the detector signal of the 1# continuous casting roller table R1 are controlled by the PLC control system to accurately transport the steel billet to the rolling mill. The laser detection data is fused in the PLC system to accurately position and track the steel billet and prevent abnormalities. Intelligent algorithm: Develop a billet tracking and positioning algorithm and embed it in the PLC system. According to the steel billet movement model and multi-source data, plan the transportation path and strategy, which can self-learn and optimize, adapt to the change of working conditions, and ensure the continuous and efficient operation of the straight rolling process.

[0030] 5. Rolling parameter setting: Control the steel grade water tank, water pressure and nozzle. Determine the parameters through experiments and simulations. Remove the 2# water tank to increase the temperature entering the finishing mill. At the same time, add nozzles to the 4# water tank to keep the temperature on the cooling bed within the controllable range.

[0031] Parameter optimization model: Establish a rolling process parameter optimization model through experiments, simulations and data analysis. Considering the steel billet material, temperature, rolling mill performance and product quality requirements, use the optimization algorithm to find the key parameters of each rolling pass. The intelligent control system adjusts the rolling mill in real time according to this to ensure stable rolling, qualified products and equipment life. Water tank control: Develop a precise control system for the water tank. Control the water pressure, water flow and nozzle parameters according to the rolling stage. In the initial stage, the water pressure is low and the flow rate is large, and then adjusted appropriately in the later stage. Cooperate with the process optimization model to dynamically control the temperature and improve the stability of cooling and product quality.

[0032] Example

[0033] On August 31, 2024, a straight rolling HRB500E plan was formulated and trial rolling started on September 1, with the rolling serial number L1Z1K124I04001, straight rolling the 25-specification HRB500E steel grade; on December 21, 2024, during the day shift, the rolling serial number was L1Z1K124L18001, which was the straight rolling process for the 20-specification HRB500E steel grade.

[0034] (1) Significantly reduced costs:

[0035] The straight rolling process reduces the oxidation loss from 0.9% to 0.3%. Calculated according to the annual output of 1.7 million tons of the line, the annual increased profit is 33.66 million yuan; the gas consumption is reduced from an average of 174 m per ton of steel 3 to 0 m 3 , saving 59.16 million yuan in annual expenses; shutting down the heating furnace saves 3 kwh of electricity per ton of steel, saving 3.06 million yuan in annual electricity bills. After deducting some expenses, the annual increased profit is 98.58 million yuan, significantly improving the economic benefits and reducing the maintenance cost of the heating furnace.

[0036] There is no need to frequently maintain the heating furnace, and human, material and financial resources can be redirected elsewhere, enhancing the competitiveness of the enterprise.

[0037] (2) Improved product quality:

[0038] Electromagnetic supplementary heating and temperature monitoring and control can make the billet reach above 920°C and the temperature difference between the head and the tail within 35°C, improve the stress of the rolled piece, avoid head billet cracking, etc., improve the dimensional accuracy and surface quality, reduce the rejection rate, and enhance the market competitiveness.

[0039] The rolling process and the water tank control cooperate to stabilize the key parameters, ensure good plastic deformation of the billet, obtain qualified metallographic and mechanical properties, and meet the quality requirements of the high-end market.

[0040] (3) Improvement in production efficiency:

[0041] The heating furnace link is omitted, the process is shortened, the residence time is reduced, and the billet positioning and tracking technology prevents transportation problems, improving the production rhythm and efficiency.

[0042] The intelligent control system realizes full-process automation, reduces human errors and interventions, improves the response and coordination speed, helps the enterprise to produce efficiently, adapt to the market, and enhances the competitive advantage.

[0043] The present invention is not limited to the above embodiments. Anyone should know that structural changes made under the inspiration of the present invention, as long as they have the same or similar technical solutions as the present invention, all fall within the protection scope of the present invention.

[0044] The technologies, shapes, and structures not described in detail in the present invention are all well-known technologies.

Claims

1. A direct rolling method for 165mm square billet of HRB500E steel grade with a length of 16 meters, characterized in that, It includes the following steps: 1) Direct rolling path planning: After the continuous casting produces a 16-meter billet, it is directly sent to the rolling line for rolling through the direct rolling roller table without passing through the reheating furnace. 2) Direct rolling roller table control: Use the laser detector of the 1# continuous casting roller table R1, the hot metal detector of the 3# direct rolling roller table H7, and the hot metal detector of the 7# direct rolling roller table H6 to determine the waiting position of the billet. 3) Electromagnetic supplementary heating: When the hot metal detector of the 3# direct rolling roller table H7 detects the billet, the electromagnetic supplementary heating device automatically adjusts the power according to the billet temperature. After the billet leaves the 3# direct rolling roller table H7, the direct rolling roller table resumes high-speed feeding to the rolling mill after a time delay. 4) Billet positioning: An image recognition system is set at the 1# continuous casting roller table R1 of the reheating furnace. 5) Rolling parameter setting: Control of the steel grade water tank and nozzles.

2. The direct rolling method for 16m 165mm square billet of HRB500E steel grade according to claim 1, characterized in that, The 16-meter billet in step 1) is quickly transferred into the direct rolling roller table through the continuous casting roller table and the collecting roller table.

3. The direct rolling method for 16m 165mm square billet of HRB500E steel grade according to claim 1, characterized in that, In step 2), when determining the waiting position of the billet, the direct rolling roller table runs at a high speed of 4.5 m / s under normal conditions. The start and stop of the billet are controlled according to the subsequent waiting billet situation, and the tapping cycle is set to prevent billet stacking.

4. The direct rolling method for 16-meter 165mm square billet of HRB500E steel grade according to claim 1, characterized in that, In step 3), after the hot metal detector of the 3# direct rolling roller table H7 detects the billet, the roller speed of the direct rolling roller table drops from 4.5 m / s to 0.4 m / s, and the electromagnetic supplementary heating device controls the billet to reach above 920°C with a head and tail temperature difference within 35°C.

5. The direct rolling method for 16-meter 165mm square billet of HRB500E steel grade according to claim 1, characterized in that, The electromagnetic supplementary heating device controls the direct rolling current not to be overloaded. The drawing speed of the continuous caster shall not be lower than 3.9 m / min. The electromagnetic supplementary heating cancels segmented heating, and the head heating time is changed from 5 seconds to 8 seconds.

6. The direct rolling method for 16m 165mm square billet of HRB500E steel grade according to claim 1, characterized in that, In step 4), the image recognition system uses an infrared camera. The infrared camera collects image data and transmits it to the processing station for position analysis. The image data after the position analysis by the processing station and the detector signal of the 1# continuous casting roller table R1 are controlled by the PLC control system to accurately transport the billet to the rolling mill.

7. The direct rolling method for 16m 165mm square billet of HRB500E steel grade according to claim 1, characterized in that, In step 5), for the control of the steel grade water tank and nozzles: Remove the 2# water tank and add nozzles to the 4# water tank at the same time.