A hot strip mill web detection apparatus and method

Abstract

The application provides a hot-rolled strip wave detection device and method, which comprises a host computer, a data storage server and a plurality of laser ranging sensors installed below the entry table of a hot finishing mill; the detection direction of the laser ranging sensors is perpendicular to the strip input in the incoming process of the hot finishing mill above the laser ranging sensors, so as to collect the wave state data of the strip input in the incoming process and store the collected data in the data storage server; the host computer processes the wave state data stored in the data storage server to generate a complete wave curve of the strip in the production process of the strip; the host computer calculates the standard deviation value of the wave curve of the strip to determine whether the value is reasonable; and when the deviation value of the wave curve is abnormally large, an alarm information is output; the application can detect the wave condition of the strip input in the entry of the hot finishing mill in real time, quickly and accurately determine the current wave condition of the input in the entry, take different measures for adjustment, and ensure the thickness difference quality stability of the hot-rolled aluminum coil.

Description

Technical Field

[0001] This invention relates to the field of metal processing technology, and in particular to a device and method for detecting wave patterns in hot-rolled strip. Background Technology

[0002] Thickness variation and shape of aluminum sheet and strip are crucial indicators for quality control in hot rolling mills. Excellent thickness variation and shape of hot-rolled finished products are essential for producing high-grade finished products in cold rolling. For hot continuous rolling lines, the thickness variation and shape of finished aluminum coils exhibit heritability; that is, the thickness variation and shape of products from upstream processes directly affect the thickness variation and shape of products from downstream processes. Therefore, ensuring the quality of thickness variation and shape of aluminum sheet and strip finished products at each process is extremely important for controlling the quality of the final finished aluminum coil. As the final process in aluminum hot continuous rolling lines, the thickness variation quality of the finished product from the hot finishing mill is a key indicator for evaluating the quality of aluminum coils. The thickness variation of finished aluminum coils from the hot finishing mill is greatly affected by the medium wave of the incoming material from the upstream hot roughing mill. If the medium wave of the strip finished from the hot roughing mill is large, the thickness variation of the finished aluminum coil from the hot finishing mill will be poor.

[0003] For hot-rolled aluminum coils, thickness variation is a key indicator for evaluating product quality. Because hot-rolled product quality exhibits heritability, the size of the waviness in the incoming material of both the hot roughing and hot finishing mills significantly impacts the thickness variation of the finished product. The waviness in the incoming hot finishing material indicates that during the roughing process, the strip elongates more in the middle of the width direction than on the sides, resulting in a thinner center. This waviness manifests as a wave in the middle of the strip along its length. This uneven stress release directly affects the thickness variation of the finished hot-finished strip. Large waviness in the incoming material leads to poor thickness variation in the finished product. Therefore, ensuring the quality of the waviness in the hot-rolled strip is crucial. However, the intermediate strip after hot rolling is generally thick, and without corresponding testing equipment, the waviness is difficult to quantify. Production personnel often rely on visual observation of the incoming material during on-site monitoring and adjust the bending rolls or cooling curves based on experience. Because the judgment of waviness is subjective, it is impossible to effectively control the waviness of the incoming material. Furthermore, since the waviness of the incoming strip cannot be quantified and recorded, if the thickness variation of the hot-rolled aluminum coil is poor, it is impossible to investigate the waviness data of the abnormal coil. For aluminum coils with abnormal thickness variation caused by large waviness in the incoming material, it is impossible to accurately and effectively trace the source of the thickness variation quality problem, which is detrimental to the quality control of the thickness variation of hot-rolled aluminum coils.

[0004] During the roughing process of strip rolling, the metal temperature reaches as high as 500-600 degrees Celsius. The heat released from the direct contact between the rolls and the high-temperature metal, as well as the relative sliding of the rolls and the deformation of the metal, causes the roll temperature to rise. This is the heat input of the rolls during the rolling process. At the same time, the cooling emulsion and air carry away heat from the rolls, causing the work roll temperature to drop. This is the heat output of the rolls. After continuous rolling for a period of time, the heat input and heat output of the rolls reach equilibrium. However, when the equilibrium temperature is too high, i.e., the roll temperature is too high, the roughing work rolls experience thermal expansion, leading to an increase in the crown. Due to the increased roll crown, the longitudinal extension of the strip in the middle of the cross-section is greater than that at the edges, resulting in a wave in the strip's rolling direction with a period equal to the rotation period of the work rolls, thus generating a medium wave.

[0005] This invention proposes a solution to the above-mentioned problems. Summary of the Invention

[0006] This invention proposes a device and method for detecting the mid-wave pattern of hot-rolled strip. It enables real-time detection of the mid-wave pattern of the incoming strip at the hot finishing mill inlet and records it in a data storage server. Based on fluctuations in the distance sensor readings, production operators can quickly and accurately determine the current mid-wave pattern of the incoming strip and take appropriate adjustments to ensure stable thickness variation in the finished hot-rolled aluminum coils. Furthermore, the mid-wave pattern data for each finished aluminum coil is stored in the data storage server, allowing production personnel to retrieve and view the mid-wave pattern curves of each historical finished aluminum coil at any time, facilitating the traceability of quality issues.

[0007] The present invention adopts the following technical solution.

[0008] A mid-wave detection device for hot-rolled strip includes a host computer, a data storage server, and multiple laser ranging sensors installed below the entrance roller table of a hot finishing mill. The detection direction of the laser ranging sensors is perpendicular to the strip input during the incoming process of the hot finishing mill, so as to collect the mid-wave state data of the strip input during the incoming process and store the collected data in the data storage server. The host computer processes the mid-wave state data stored in the data storage server to generate a complete mid-wave curve of the strip during the strip production process. The host computer calculates the standard deviation value of the mid-wave curve of the strip to determine whether the value is reasonable, and outputs an alarm message when the deviation value of the mid-wave curve is abnormally large.

[0009] The hot finishing mill is located in the last process of the aluminum hot continuous rolling production line; the strip input to the hot finishing mill during the material receiving process comes from the hot roughing mill.

[0010] The laser rangefinder is a high-precision laser rangefinder used to detect the distance L between the strip above the roller conveyor and the laser rangefinder in real time during the production process. If the mid-wave of the incoming strip is small, the distance L fluctuates little; if the mid-wave of the incoming strip is large, the distance L fluctuates greatly. The laser rangefinder uses this distance L data as the acquisition data representing the mid-wave condition of the incoming material. The distance L is first converted into an analog signal of 4-20mA and then sent to the data storage server for storage.

[0011] The alarm method based on the hot-rolled strip medium wave detection device adopts the hot-rolled strip medium wave detection device described above. The alarm method is a real-time alarm method. The detection distance value L of the laser rangefinder is processed and judged in the data storage server. If the fluctuation amplitude of L is greater than the alarm threshold, an alarm will be generated to prompt the operator that the medium wave of the incoming material in the current production process is too large. Specifically, it includes the following steps: Step S1: Cut off the data of the first and last 2 meters of the complete medium wave curve of the incoming strip to filter out the abnormal fluctuation data of medium wave detection caused by the different shapes of the first and last ends.

[0012] Step S2: Calculate the standard deviation using the remaining medium wave curve data. Use the standard deviation value to show the fluctuation of the medium wave value of the strip. The calculation formula is as follows:

[0013]

[0014] S x Standard deviation

[0015] average value

[0016] n: number of samples;

[0017] Step S3: Determine whether the standard deviation is greater than the alarm threshold. If the calculated standard deviation is greater than the alarm threshold, it indicates that the medium wave condition of the strip exceeds the standard. Output an alarm to remind the operator to pay attention to the medium wave quality of the incoming material.

[0018] The standard deviation of the mid-wave in the alarm threshold is a value greater than 2.

[0019] The method for reducing medium wave intensity based on the medium wave detection device for hot-rolled strip, using the aforementioned hot-rolled strip medium wave detection device, is applicable to medium waves caused by excessive thermal expansion in the middle of the roughing work roll of a hot roughing mill, resulting in excessive strip elongation in the middle section. The method includes the following steps:

[0020] Step A1: The finished product from the hot roughing mill is transported to the hot finishing mill via a roller conveyor for the next rolling process; Step A2: The laser rangefinder of the hot finishing mill detects the distance L from the sensor to the strip above the entrance roller conveyor. The fluctuation amplitude of this distance L is the mid-wave data of the strip, and this data is transmitted to the data storage server.

[0021] Step A3: The data storage server saves the raw wave data of each product's incoming material and processes and calculates the wave data of the strip to obtain the standard deviation data of the wave data of the strip. It then determines whether the calculated standard deviation value of the wave data of the strip is greater than the alarm threshold. If the value is greater than the alarm threshold, the host computer will display a large wave alarm to prompt the operator to pay attention.

[0022] Step A4: After the operator observes the alarm information and standard deviation value of the strip waviness through the host computer, they can reduce the temperature in the middle of the roughing mill work roll by reducing the roughing mill rolling speed, adjusting the emulsion spray distribution curve of the work roll cooling spray bar beam, or recalibrating the stand to zero, so as to reduce the thermal expansion of the work roll of the hot roughing mill and thus improve the waviness of the strip input to the hot finishing mill.

[0023] The strip is a 3104 alloy strip.

[0024] This invention enables real-time detection of the wave pattern in the incoming strip at the hot finishing mill inlet, recording it in a data storage server. Based on fluctuations in the distance sensor readings, production operators can quickly and accurately determine the current wave pattern and take appropriate adjustments to ensure stable thickness variation in the finished hot-rolled aluminum coils. Furthermore, the wave pattern data for each finished aluminum coil is stored in the data storage server, allowing production personnel to access and view historical wave pattern curves for each finished coil at any time, facilitating the tracing of quality issues. Attached Figure Description

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0026] Appendix Figure 1 This is a schematic diagram of the present invention;

[0027] Appendix Figure 2 This is a schematic diagram illustrating the principle of the laser rangefinder sensor for detecting strip materials according to the present invention;

[0028] Appendix Figure 3 This is a schematic diagram of the detection of 3104 alloy strip displayed on the host computer interactive interface in the embodiment (the figure shows the strip with large medium wave and its thickness difference data after production, as well as the strip with normal medium wave and its thickness difference data after production).

[0029] In the diagram: 1. Hot finishing mill inlet roller conveyor; 2. Laser rangefinder sensor; 3. Data storage server; 4. Host computer; 5. Strip material input during the hot finishing mill incoming process; 6. Medium wave of the strip; 7. Region with large medium wave of the strip; 8. Region with small medium wave of the strip. Detailed Implementation

[0030] As shown in the figure, a mid-wave detection device for hot-rolled strip includes a host computer 4, a data storage server, and multiple laser rangefinders 2 installed below the entrance roller table 1 of the hot finishing mill. The detection direction of the laser rangefinders is perpendicular to the strip 5 input during the incoming process of the hot finishing mill, so as to collect the mid-wave status data of the strip input during the incoming process and store the collected data in the data storage server 3. The host computer processes the mid-wave status data stored in the data storage server to generate a complete mid-wave curve of the strip during the strip production process. The host computer calculates the standard deviation value of the mid-wave curve of the strip to determine whether the value is reasonable, and outputs an alarm message when the deviation value of the mid-wave curve is abnormally large.

[0031] The hot finishing mill is located in the last process of the aluminum hot continuous rolling production line; the strip input to the hot finishing mill during the material receiving process comes from the hot roughing mill.

[0032] The laser rangefinder is a high-precision laser rangefinder, used to detect the distance L between the strip above the roller conveyor and the laser rangefinder in real time during the production process. Figure 1 , Figure 2 As shown, if the medium wave of the incoming material strip is small, the distance L fluctuates little; if the medium wave of the incoming material strip is large, the distance L fluctuates greatly. The laser rangefinder uses this distance L data as the acquisition data representing the medium wave condition of the incoming material. The distance L is first converted into an analog signal of 4-20mA and then sent to the data storage server for storage.

[0033] The alarm method based on the hot-rolled strip medium wave detection device adopts the hot-rolled strip medium wave detection device described above. The alarm method is a real-time alarm method. The detection distance value L of the laser rangefinder is processed and judged in the data storage server. If the fluctuation amplitude of L is greater than the alarm threshold, an alarm will be generated to prompt the operator that the medium wave of the incoming material in the current production process is too large. Specifically, it includes the following steps: Step S1: Cut off the data of the first and last 2 meters of the complete medium wave curve of the incoming strip to filter out the abnormal fluctuation data of medium wave detection caused by the different shapes of the first and last ends.

[0034] Step S2: Calculate the standard deviation using the remaining medium wave curve data. Use the standard deviation value to show the fluctuation of the medium wave value of the strip. The calculation formula is as follows:

[0035]

[0036] S x Standard deviation

[0037] average value

[0038] n: number of samples;

[0039] Step S3: Determine whether the standard deviation is greater than the alarm threshold. If the calculated standard deviation is greater than the alarm threshold, it indicates that the medium wave condition of the strip exceeds the standard. Output an alarm to remind the operator to pay attention to the medium wave quality of the incoming material.

[0040] The standard deviation of the mid-wave in the alarm threshold is a value greater than 2.

[0041] The method for reducing medium wave intensity based on the medium wave detection device for hot-rolled strip, using the aforementioned hot-rolled strip medium wave detection device, is applicable to medium waves caused by excessive thermal expansion in the middle of the roughing work roll of a hot roughing mill, resulting in excessive strip elongation in the middle section. The method includes the following steps:

[0042] Step A1: The finished product from the hot roughing mill is transported to the hot finishing mill via a roller conveyor for the next rolling process; Step A2: The laser rangefinder of the hot finishing mill detects the distance L from the sensor to the strip above the entrance roller conveyor. The fluctuation amplitude of this distance L is the mid-wave data of the strip, and this data is transmitted to the data storage server.

[0043] Step A3: The data storage server saves the raw wave data of each product's incoming material and processes and calculates the wave data of the strip to obtain the standard deviation data of the wave data of the strip. It then determines whether the calculated standard deviation value of the wave data of the strip is greater than the alarm threshold. If the value is greater than the alarm threshold, the host computer will display a large wave alarm to prompt the operator to pay attention.

[0044] Step A4: After the operator observes the alarm information and standard deviation value of the strip waviness through the host computer, they can reduce the temperature in the middle of the roughing mill work roll by reducing the roughing mill rolling speed, adjusting the emulsion spray distribution curve of the work roll cooling spray bar beam, or recalibrating the stand to zero, so as to reduce the thermal expansion of the work roll of the hot roughing mill and thus improve the waviness of the strip input to the hot finishing mill.

[0045] The strip is a 3104 alloy strip.

[0046] Example:

[0047] like Figure 3As shown in the example, this case uses 3104 alloy strip. In this example, the incoming strip with coil number R4112123 has a large wave pattern, with a large fluctuation amplitude in the wave curve. The standard deviation of the wave curve reaches 4.56, which is greater than the target value of 2. After hot finishing, the thickness difference of the finished product is poor. As shown in the thickness difference curve, the standard deviation of the thickness difference is 7.8473, which does not meet the product thickness difference quality requirements. The operator sees a wave alarm on the host computer and checks the wave curve, determining that the poor wave pattern of the incoming material is causing the poor thickness difference of the finished product. The operator then reduced the production speed to increase the heat output of the rolls and reduced the crown of the roughing rolls to produce the next coil of R4112122 product. After the adjustment, the wavy condition of the incoming hot finishing roll of the next product was significantly improved, and the standard deviation of the wavy condition decreased to 1.89, indicating that the wavy condition was effectively controlled. The thickness difference of the finished aluminum coil from the hot finishing mill also decreased to 6.7677, indicating that the thickness difference quality of the finished aluminum coil was also effectively improved.

Claims

1. A wave detection device for hot-rolled strip, characterized in that: The device includes a host computer, a data storage server, and multiple laser ranging sensors installed below the entrance roller table of the hot finishing mill. The detection direction of the laser ranging sensors is perpendicular to the strip material input during the hot finishing mill's incoming process, so as to collect the mid-wave state data of the strip material input during the incoming process and store the collected data in the data storage server. The host computer processes the mid-wave state data stored in the data storage server to generate a complete mid-wave curve of the strip material during the strip material production process. The host computer calculates the standard deviation value of the mid-wave curve of the strip material to determine whether the value is reasonable, and outputs an alarm message when the deviation value of the mid-wave curve is abnormally large. The laser rangefinder is a high-precision laser rangefinder used to detect the distance L between the strip above the roller conveyor and the laser rangefinder in real time during the production process. If the mid-wave of the incoming strip is small, the distance L fluctuates little; if the mid-wave of the incoming strip is large, the distance L fluctuates greatly. The laser rangefinder uses this distance L data as the acquisition data representing the mid-wave condition of the incoming material. The distance L is first converted into an analog signal of 4-20mA and then sent to the data storage server for storage.

2. The wave detection device for hot-rolled strip according to claim 1, characterized in that: The hot finishing mill is located in the last process of the aluminum hot continuous rolling production line; the strip input to the hot finishing mill during the material receiving process comes from the hot roughing mill.

3. An alarm method based on a hot-rolled strip medium-wave detection device, employing the hot-rolled strip medium-wave detection device as described in claim 1, characterized in that: The alarm method is a real-time alarm method. The detection distance value L of the laser rangefinder is processed and judged in the data storage server. If the fluctuation amplitude of L is greater than the alarm threshold, an alarm will be generated to prompt the operator that the medium wave of the incoming material in the current production process is too large. The specific steps include: Step S1: Cut off the data of the first and last 2 meters of the complete medium wave curve of the incoming material strip to filter out abnormal fluctuation data of medium wave detection caused by different shapes at the beginning and end; Step S2: Calculate the standard deviation using the remaining medium wave curve data. Use the standard deviation value to show the fluctuation of the medium wave value of the strip. The calculation formula is as follows: S x Standard deviation average value n: number of samples; Step S3: Determine whether the standard deviation is greater than the alarm threshold. If the calculated standard deviation is greater than the alarm threshold, it indicates that the medium wave condition of the strip exceeds the standard. Output an alarm to remind the operator to pay attention to the medium wave quality of the incoming material.

4. The alarm method based on the medium wave detection device for hot-rolled strip according to claim 3, characterized in that: The standard deviation of the mid-wave in the alarm threshold is a value greater than 2.

5. A method for reducing the medium wave intensity based on a medium wave intensity detection device for hot-rolled strip, using the medium wave intensity detection device for hot-rolled strip as described in claim 2, characterized in that: The reduction method is applicable to medium-wave strips caused by excessive thermal expansion in the middle of the roughing work rolls of a hot roughing mill, resulting in excessive strip elongation in the middle section. The method includes the following steps: Step A1: The finished product from the hot roughing mill is transported to the hot finishing mill via roller conveyor for the next rolling process; Step A2: The laser rangefinder of the hot finishing mill detects the distance L from the sensor to the strip above the entrance roller table. The fluctuation amplitude of this distance L is the mid-wave data of the strip, and this data is transmitted to the data storage server. Step A3: The data storage server saves the raw wave data of the incoming material for each product, and processes and calculates the wave data of the strip to obtain the standard deviation data of the wave data of the strip. It then determines whether the calculated standard deviation value of the wave data of the strip is greater than the alarm threshold. If the value is greater than the alarm threshold, the host computer will display a large wave alarm to prompt the operator to pay attention. Step A4: After the operator observes the alarm information and standard deviation value of the strip waviness through the host computer, they can reduce the temperature in the middle of the roughing mill work roll by reducing the roughing mill rolling speed, adjusting the emulsion spray distribution curve of the work roll cooling spray bar beam, or recalibrating the stand to zero, so as to reduce the thermal expansion of the work roll of the hot roughing mill and thus improve the waviness of the strip input to the hot finishing mill.

6. The method for reducing medium wave intensity based on a medium wave detection device for hot-rolled strip according to claim 5, characterized in that: The strip is a 3104 alloy strip.

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