A method for controlling a wide and thick gauge stainless steel cold plate during a non-rolling section

Abstract

The present application belongs to the field of rolling control technology of multi-roller cold rolling mill, and provides a kind of wide and thick specification stainless steel cold plate unrolled section control method, including steel ring inner ring and outer ring plus lead tape, and the length and thickness of lead tape are specified;Outer ring unrolled section intelligent control: the first pass uses the count of coiling encoder, when the count is greater than 1.5 turns and less than 2 turns, the rolling mill completes threading;Inner ring unrolled section intelligent control: the first pass tail uses thickness gauge to measure thickness, compares with the set thickness of base material, calculates the comprehensive deviation proportion coefficient, which is used as the weld recognition control point;Calculate the parking time control to stop automatically;The method of the present application realizes accurate identification of unrolled section, accurate calculation of coiling turns and accurate control of inner ring unrolled section for wide single stand cold rolling mill, effectively improves production efficiency and yield.

Description

Technical Field

[0001] This invention belongs to the field of rolling control technology of multi-roll cold rolling mills, and relates to a reversible rolling production line for thick stainless steel plates and other steel coils with lead strips. Specifically, it is a method for controlling the unrolled section of thick stainless steel cold plates. Background Technology

[0002] Wide-width reversible cold rolling mills are core equipment for producing high-grade, thick stainless steel plates with superior surface finish. They offer high rolling pressure, high speed, and excellent plate shape, and are widely used for high-value-added 2B and BA surface finish products. In actual production, steel coils are often produced using a strip guide to improve the yield rate. Existing control systems lack accurate identification, length measurement, thickness determination, and dynamic stop linkage functions for the unrolled section. Inaccurate positioning of the unrolled section, delayed or premature stoppages, and excessive manual intervention make it difficult to meet the demands of efficient and stable production. Therefore, there is an urgent need to develop a comprehensive unrolled section detection and intelligent control method to address these technical deficiencies. Summary of the Invention

[0003] The purpose of this invention is to provide a control method for the unrolled section of wide and thick stainless steel cold-rolled sheets, which solves the problems of inaccurate strip identification, large coiling counting error, large stopping position deviation, high failure rate, and low yield in the existing strip rolling process. It realizes the full-process automated and precise control of unrolled section coiling, identification, and stopping, thereby improving rolling stability, yield, and equipment safety.

[0004] The technical solution adopted by the present invention to achieve the above objectives is as follows: A method for controlling the unrolled sections of wide and thick stainless steel cold-rolled sheets includes: S1. Standardize the guide belt specifications; Add guide strips to the inner and outer rings of the steel ring, and standardize the length and thickness of the guide strips; S2, control of the unrolled outer ring; The first pass utilizes the counting of the winding encoder. When the count is greater than 1.5 turns but less than 2 turns, the rolling mill completes the strip threading. S3, Inner ring unrolled section control; The thickness at the end of the first pass is measured using a thickness gauge and compared with the set thickness of the base material. The comprehensive deviation ratio coefficient is calculated and used as the weld identification control point. The stopping time is calculated to control automatic stopping. S4. Proceed to the next control step.

[0005] Furthermore, the standard guide length L = L1 + D * 3.14 * 1.5 * K / 1000; In the formula, L1 is the distance from the coiler to the main mill work roll, D is the coiler drum diameter, and K is the safety distance factor from the unrolled section to the main mill work roll, K=0.9~0.95; The standard lead-in tape thickness H = (60%~80%) * H0; In the formula, H0 is the thickness of the base material.

[0006] Furthermore, the specific steps of S2 include: S21. Determine whether to issue a jaw engagement command by checking whether the belt head reaches the right jaw of the coiling jaws. S22. Use the clamp expansion and contraction pressure data to determine if it is greater than 180 bar as the zeroing signal for the number of revolutions, and use a clockwise rotation signal as the positive rotation signal command to serve as the starting point for the number of revolutions calculation. S23. The encoder on the coiler uploads the counting signal to the PLC in real time. When the number of coils is greater than 1.5 and less than 2, it is used as a rolling preparation ready signal, and the rolling mill is ready to start.

[0007] Furthermore, the specific steps of S3 include: S31. The base deviation ΔH = H0 - H1 is obtained by comparing the real-time measured value H1 of the thickness gauge with the set value H0 of the base material. S32. Based on the basic deviation value and the formula K1=(△H / H0)*100%, the comprehensive deviation coefficient K1 is obtained; S32. Use the PLC program to set K1 > 20% as the weld position positioning condition; S33. The automatic stopping function is achieved by using the stopping time formula t=(L2 / v)*K, and the unrolled section stops in the safe area; where L2 is the distance from the thickness gauge to the main mill work roll, v is the belt tail linear speed, and K is the safety distance coefficient from the unrolled section to the main mill work roll, K=0.9~0.95; S34, Proceed to the next round of intelligent control.

[0008] The beneficial effects of the method of this invention are: 1. By standardizing the specifications of the lead belt, a foundation is provided for subsequent automatic control functions, which can effectively reduce the need for manual confirmation of unrolled sections.

[0009] 2. By establishing biting jaw command, drum expansion and contraction pressure judgment program, and coiler turn count judgment program, the control of the unrolled section of the outer ring was realized.

[0010] 3. By establishing a comparison program between the actual thickness measured by the thickness gauge and the thickness of the base material, the weld position can be effectively detected. By calculating the safe stopping time, intelligent control of the unrolled section of the inner ring is realized.

[0011] By adopting this invention, the intelligent control of the unrolled outer and inner ring sections was successfully solved, and the rolling efficiency and yield were successfully improved. Attached Figure Description

[0012] Figure 1This is the flowchart of the intelligent control logic for the outer unrolled section; Figure 2 This is the flowchart of the intelligent control logic for the inner unrolled section. Detailed Implementation

[0013] The present invention will be further described below with reference to embodiments and accompanying drawings: A method for controlling the unrolled sections of wide and thick stainless steel cold-rolled sheets includes: S1. Guide belt specifications; The inner and outer rings of the steel coil are reinforced with guide strips. The length and thickness of the guide strips are specified as follows: The length of the guide belt L (m) = L1 + D * 3.14 * 1.5 * K / 1000; The thickness of the lead tape H (mm) = (60%~80%) * H0.

[0014] In the formula: L1 — the distance from the coiler to the main mill work roll, in meters; D — Coiler drum diameter, unit: mm; K — Safety distance factor from the unrolled section to the main mill work roll, K = 0.9~0.95; H0 — Base material thickness, unit: mm.

[0015] S2, Intelligent control of the outer ring unrolled section The first pass uses the jaw engagement command and jaw expansion / contraction pressure data as the zeroing signal for the number of revolutions, and collects the clockwise rotation signal as the positive rotation signal command, serving as the starting point for the number of revolutions calculation. The encoder on the coiler uploads the counting signal to the PLC in real time. When the number of revolutions is greater than 1.5 and less than 2, it serves as the rolling preparation ready signal, indicating that the mill is ready to start. The specific logic is as follows: Figure 1 As shown; S3, Intelligent control of unrolled inner ring section The initial thickness gauge at the tail end of the first pass compares the real-time measured value H1 with the set value H0 of the base material to obtain the basic deviation ΔH. Based on the basic deviation value and the relevant formula "K1=(ΔH / H0)*100%", the comprehensive deviation coefficient K1 is obtained. The PLC program uses "K1>20%" as the weld position positioning condition, and then uses the stopping time formula "t =(L2 / v)*K" to achieve automatic stopping. The specific logic is as follows: Figure 2 As shown; In the formula: △H—— thickness basic deviation △H, △H=H0-H1, unit: mm; H1 — Measured data from the thickness gauge, unit: mm; H0 — Base material set thickness, unit: mm; K1 — Overall deviation ratio coefficient; t — Parking time, in seconds; L2 — Distance from the thickness gauge to the main rolling mill work roll, in meters; V — linear velocity with tail, m / min; K—Safety distance factor from the unrolled section to the main mill work rolls, K=0.9~0.95; Example

[0016] Taking the wide-width Sendzimir 20-roll mill as an example: The wide-width Sendzimir 20-roll mill is designed with a drum-to-work roll distance of L1=6.5m, a thickness gauge-to-work roll distance of L2=4m, and a drum diameter of D=762mm. For 300 series cold-rolled steel strip, the base material thickness H0=6.0mm, and a safety distance factor K=0.95 from the unrolled section to the main mill work roll. This method is used to control the unrolled sections of wide and thick stainless steel cold-rolled sheets: S1. Specification of lead-in tape length L (m) and lead-in tape thickness H (mm) L=L1+D*3.14*1.5*k / 1000=9.9m; H=70% H0=4.2mm.

[0017] S2. Outer Ring Unrolled Section Control: After the tape is threaded onto the coiler, when there is a "jaw engagement command and jaw engagement pressure greater than 180 bar" signal, the number of turns is reset to zero. The forward rotation (clockwise rotation) signal command serves as the starting point for the number of turns calculation. When the number of turns is greater than 1.5 and less than 2, the indicator light flashes to remind the production personnel that the tape threading is complete and the conditions for rolling are met.

[0018] S3. Control of unrolled inner ring: The thickness deviation ratio coefficient calculation program "K1=(△H / H0)*100%" is used to obtain "K1>20%" as the weld detection position signal. At the same time, after the safe stopping time program "t=(L2 / v)*K=11.4s", a stop command is sent, and the unrolled section is accurately stopped in the safe area.

Claims

1. A method for controlling the unrolled sections of thick stainless steel cold-rolled sheets, characterized in that: include: S1. Standardize the guide belt specifications; Add guide strips to the inner and outer rings of the steel ring, and standardize the length and thickness of the guide strips; S2, control of the unrolled outer ring; The first pass utilizes the counting of the winding encoder. When the count is greater than 1.5 turns but less than 2 turns, the rolling mill completes the strip threading. S3, Inner ring unrolled section control; The thickness at the end of the first pass is measured using a thickness gauge and compared with the set thickness of the base material. The comprehensive deviation ratio coefficient is calculated and used as the weld identification control point. The stopping time is calculated to control automatic stopping. S4. Proceed to the next control step.

2. The method for controlling the unrolled sections of wide and thick stainless steel cold-rolled sheets according to claim 1, characterized in that: The length of the specified guide strip is L = L1 + D * 3.14 * 1.5 * K / 1000; In the formula, L1 is the distance from the coiler to the main mill work roll, D is the coiler drum diameter, and K is the safety distance factor from the unrolled section to the main mill work roll, K=0.9~0.95; The thickness of the guide tape is specified as H = (60%~80%) * H0; In the formula, H0 is the thickness of the base material.

3. The method for controlling the unrolled section of a wide and thick stainless steel cold-rolled sheet according to claim 1, characterized in that: The specific steps in S2 include: S21. Determine whether to issue a jaw engagement command by checking whether the belt head reaches the right jaw of the coiling jaws. S22. Use the clamp expansion and contraction pressure data to determine if it is greater than 180 bar as the zeroing signal for the number of revolutions, and use a clockwise rotation signal as the positive rotation signal command to serve as the starting point for the number of revolutions calculation. S23. The encoder on the coiler uploads the counting signal to the PLC in real time. When the number of coils is greater than 1.5 and less than 2, it is used as a rolling preparation ready signal, and the rolling mill is ready to start.

4. The method for controlling the unrolled sections of wide and thick stainless steel cold-rolled sheets according to claim 1, characterized in that: The specific steps in S3 include: S31. The base deviation ΔH = H0 - H1 is obtained by comparing the real-time measured value H1 of the thickness gauge with the set value H0 of the base material. S32. Based on the basic deviation value and the formula K1=(△H / H0)*100%, the comprehensive deviation coefficient K1 is obtained; S32. Use the PLC program to set K1 > 20% as the weld position positioning condition; S33. The automatic stopping function is achieved by using the stopping time formula t=(L2 / v)*K, and the unrolled section stops in the safe area; where L2 is the distance from the thickness gauge to the main mill work roll, v is the belt tail linear speed, and K is the safety distance coefficient from the unrolled section to the main mill work roll, K=0.9~0.

95. S34, Proceed to the next round of intelligent control.

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