Methods for preventing steel pile-up in roughing mill vertical and horizontal roll mills
By using the physical parameters of horizontal and vertical rolling mills to determine deviation and slippage during odd and even rolling passes, and triggering fast stop control, the problem of steel piling accidents escalating in hot continuous rolling production lines was solved, thereby improving production efficiency and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI MEISHAN IRON & STEEL CO LTD
- Filing Date
- 2021-09-30
- Publication Date
- 2026-06-02
AI Technical Summary
In hot strip rolling production lines, strip deviation or slippage during roughing mill rolling can lead to steel pile-up accidents, which are difficult to handle and affect production efficiency and costs. In particular, handling steel pile-up in the narrow space between vertical and horizontal rolling mills takes a long time.
By determining whether the rolling passes are odd or even, the physical parameters of the horizontal and vertical rolling mills are used to judge deviation and slippage during odd and even passes, triggering fast stop control to prevent the steel pile-up accident from escalating.
It enables timely and accurate judgment and rapid stop control of roughing mill deviation and slippage, shortens the handling time of steel pile-up accidents, avoids long-term production line downtime, improves production efficiency and reduces costs.
Smart Images
Figure CN115870348B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for preventing steel piling during the rolling of sheet and strip steel, belonging to the field of metal rolling technology. Background Technology
[0002] In hot strip rolling production lines, the roughing mill is generally equipped with a reversible vertical rolling mill and a horizontal rolling mill. The distance between the vertical and horizontal rolling mills is very close (generally within 3 meters). Since the strip steel rolled by the roughing mill is relatively thick (generally 30-180mm), once a steel pile-up accident occurs, the scrap steel disposal is very difficult, often leading to a long shutdown of the production line. Especially when the steel pile-up occurs between the vertical and horizontal rolling mills, the space around the pile-up is small and enclosed, and it is difficult to remove the rolls. The downtime for handling the steel pile-up can be as long as 16 hours or even several days, which has a significant impact on the high-efficiency and low-cost production operation of the hot strip rolling production line.
[0003] In actual production, steel piling up on roughing mills is generally caused by strip misalignment or slippage, which then leads to further misalignment. Once this happens, operators need to immediately stop the mill to prevent the pile from becoming too long and escalating the accident. However, because roughing mills typically operate at high speeds (3.0–5.8 m / s), relying on operators to observe abnormalities before stopping the mill results in a pile length of at least 10 meters, making it difficult to prevent the accident from escalating. Summary of the Invention
[0004] The technical problem to be solved by this invention is to judge and trigger a quick stop for roughing mill deviation and slippage, so as to avoid the escalation of steel pile-up accidents and shorten the handling time of steel pile-up accidents.
[0005] The technical solution proposed by this invention to solve the above-mentioned technical problems is: a method for preventing steel pile-up in roughing mills with vertical and horizontal rolls, comprising the following steps:
[0006] Step 1: Determine the rolling pass
[0007] The rolling passes are divided into odd-numbered passes and even-numbered passes. When rolling in odd-numbered passes, the billet is first rolled by a vertical roll mill and then by a horizontal roll mill. When rolling in even-numbered passes, the billet is first rolled by a horizontal roll mill and then by a vertical roll mill.
[0008] Step 2: Perform deviation judgment and fast stop control for odd-numbered rolling passes.
[0009] 1) The physical quantities involved in odd-numbered rolling processes include:
[0010] The deviation of rolling force on both sides during rolling in a horizontal roll mill, D1, in tons;
[0011] The pressure sensor on the exit side guide plate of the horizontal rolling mill detects pressure f1, in tons;
[0012] The horizontal rolling mill exit knockout image recognition and detection device detects the knockout height Y1, in millimeters;
[0013] 2) If all three of the following conditions are met simultaneously:
[0014] A. The absolute value of the difference between the maximum and minimum values of D1 is greater than 100 tons;
[0015] B.f1 > 20 tons;
[0016] C.Y1 > 800 mm;
[0017] If the rolling mill stops quickly, it will stop; otherwise, it will continue rolling normally.
[0018] Step 3: Control the head of the billet before it passes the vertical roll in even-numbered rolling passes.
[0019] 1) The physical quantities involved at this time are:
[0020] The linear velocity of the horizontal roller, V2, is expressed in meters per second.
[0021] Slip value before horizontal roll rolling;
[0022] The center-to-center distance L2 between the vertical and horizontal rolling mills, in meters;
[0023] The actual rolling force F2 for rolling steel billets on a horizontal roll mill, in tons;
[0024] The predicted rolling force SF2 for steel billets rolled by a horizontal rolling mill, in tons;
[0025] The deviation of rolling force on both sides during horizontal rolling mill rolling, D2, in tons;
[0026] 2) Slip recognition
[0027] Within the time range before the billet head passes the vertical roll, the maximum actual rolling force of the billet rolled by the horizontal roll mill is F2max, and the minimum is F2min. The determination is as follows:
[0028] (1) When F2max-SF2>600 tons, if (F2max-SF2)×0.4+SF2-F2min>1200 tons, then it is judged as rolling slippage;
[0029] (2) When F2max-SF2≤600 tons, if F2max-F2min>1200 tons, it is judged as rolling slippage;
[0030] (3) If neither of the above conditions (1) nor (2) is met, then the rolling process does not slip and the rolling is normal.
[0031] 3) Pull-off detection and quick stop control
[0032] The recording of the rolling force deviation D2 on both sides of the horizontal rolling mill is stopped when the absolute value of the difference between F2 and SF2 is less than 600 tons and the duration exceeds a certain period, starting from the generation of the steel signal. Within this time range, the maximum value of the rolling force deviation on both sides of the horizontal rolling mill is D2 max, and the minimum value is D2 min.
[0033] If the above conditions (1) or (2) are met, and the difference between D2 max and D2 min is greater than 100 tons, then the mill will be stopped quickly; otherwise, rolling will proceed normally.
[0034] Step 4: Control of the billet head after passing through the vertical rolls in even-numbered rolling passes.
[0035] 1) The physical quantities involved at this time are:
[0036] The deviation of rolling force on both sides during horizontal rolling mill rolling, D2, in tons;
[0037] The actual rolling force F2 for rolling steel billets on a horizontal roll mill, in tons;
[0038] The predicted rolling force SF2 for steel billets rolled by a horizontal rolling mill, in tons;
[0039] The pressure sensor on the upstream guide plate of the vertical rolling mill detects pressure f2, in tons;
[0040] The image recognition and detection device for the upstream knock-out head of the vertical roll mill detects the knock-out head height Y2, in millimeters.
[0041] When the time after the billet head passes the vertical roll exceeds a certain limit, D2 is recorded from the start to the end when the billet is ejected from the rolling mill. The maximum value of D2 within this time range is D2max, and the minimum value of D2 is D2min.
[0042] If all three of the following conditions are met:
[0043] (4) The absolute value of the difference between D2max and D2min is greater than 100 tons;
[0044] (5) f2 > 20 tons;
[0045] (6) Y2 > 800 mm;
[0046] If the rolling mill stops quickly, it will stop; otherwise, it will continue rolling normally.
[0047] The beneficial effects of this invention are as follows: Addressing the actual production needs of roughing mills with vertical and horizontal rolls, this invention proposes methods to determine slippage, deviation, and control the mill to either stop quickly or continue rolling normally, based on the relationships between various parameters of the horizontal and vertical roll mills during rolling, for both odd-pass and even-pass rolling. Therefore, it should be able to promptly and accurately determine and trigger a quick stop for deviation and slippage in the roughing mill, thereby preventing the escalation of steel pile-up accidents and shortening the time required to handle such accidents. Attached Figure Description
[0048] The method for preventing steel pile-up in roughing mill vertical and horizontal roll mills of the present invention will be further described below with reference to the accompanying drawings. Figure 1 This is a flowchart of the method for preventing steel pile-up in the roughing mill vertical and horizontal rolls in the embodiment. Detailed Implementation
[0049] Example 1
[0050] The method for preventing steel pile-up in the roughing mill vertical and horizontal rolls of this embodiment, taking three passes of roughing mill as an example, includes the following steps:
[0051] Step 1: Determine the rolling pass
[0052] Generally, vertical and horizontal rolling mills can perform reversible rolling, and are classified into odd-numbered and even-numbered passes based on the number of passes. In this embodiment, passes 1 and 3 are odd-numbered passes, and pass 2 is an even-numbered pass. During passes 1 and 3, the billet is first rolled by the vertical rolling mill and then by the horizontal rolling mill; during pass 2, the billet is first rolled by the horizontal rolling mill and then by the vertical rolling mill; at this time, the vertical rolling mill is generally unloaded.
[0053] Step 2: Deviance judgment and quick stop control for odd-numbered rolling passes. First, the first rolling pass is judged and controlled. The main risk of steel stacking in odd-numbered rolling passes is that after the head exits the horizontal rolling mill, it hits the side guide plate at the exit of the horizontal rolling mill and stacks up.
[0054] 1) The physical quantities involved at this time are as follows:
[0055] The rolling force deviation D1 on both sides during horizontal rolling mill rolling is 20 tons;
[0056] The pressure sensor on the guide plate at the exit of the horizontal rolling mill detects a pressure f1 of 0.1 tons.
[0057] The horizontal rolling mill exit knockout image recognition detection device detects that the knockout height Y1 is 20 mm.
[0058] 2) Determine whether the following three conditions are met:
[0059] A. The absolute value of the difference between the maximum and minimum values of D1 is greater than 100 tons;
[0060] B.f1 > 20 tons;
[0061] C.Y1 > 800 mm;
[0062] Since none of the above three conditions are met, normal rolling is carried out.
[0063] Step 3: Control the billet head before it passes the vertical roll in even-numbered rolling passes. Next, the billet head is judged and controlled before it passes the vertical roll in the second rolling pass. Since the billet passes through the horizontal roll first in even-numbered rolling passes, if the billet head slips or deviates before passing the vertical roll, the risk of the billet piling up between the vertical and horizontal roll mills is extremely high.
[0064] 1) The physical quantities involved at this time are:
[0065] The linear speed V2 of the horizontal roller rotation is 3.5 m / s;
[0066] The slip value before horizontal roll rolling is 1.07;
[0067] The center-to-center distance L2 between the vertical and horizontal rolling mills is 3 meters.
[0068] The actual rolling force F2 for rolling steel billets on a horizontal rolling mill is around 1000-2250 tons.
[0069] The predicted rolling force SF2 for rolling steel billets on a horizontal rolling mill is 2000 tons.
[0070] The deviation of rolling force on both sides during horizontal rolling mill rolling is D2, which is about 10-130 tons.
[0071] 2) Slip recognition
[0072] Within the few seconds before the billet head passes the vertical roll, the maximum actual rolling force of the billet rolled by the horizontal roll mill is F2max, which is 2250 tons, and the minimum is F2min, which is 1000 tons. The following conditions must be considered:
[0073] (1) When F2max-SF2>600 tons, if (F2max-SF2)×0.4+SF2-F2min>1200 tons, then it is judged as rolling slippage;
[0074] (2) When F2max-SF2≤600 tons, if F2max-F2min>1200 tons, it is judged as rolling slippage;
[0075] (3) If neither of the above conditions (1) nor (2) is met, then the rolling process does not slip and proceeds normally. Since F2max-SF2=2250 tons-2000 tons=250 tons≤600 tons, and F2max-F2min=2250 tons-1000 tons=1250 tons>1200 tons, condition (2) is met, it is determined that the strip slipped during the second rolling pass.
[0076] 3) Pull-off detection and quick stop control
[0077] Record the rolling force deviation D2 on both sides of the horizontal rolling mill from the time the steel signal is generated until the absolute value of the difference between F2 and SF2 is less than 600 tons and the duration exceeds seconds. The maximum value of the rolling force deviation on both sides of the horizontal rolling mill during this time range is D2max, which is 130 tons, and the minimum value is D2min, which is 10 tons.
[0078] Since the second pass meets the above condition (2), and the difference between D2max and D2min is 130 tons - 10 tons = 120 tons > 100 tons, the mill is triggered to stop quickly, and the rolling process ends.
[0079] Obviously, 1) if conditions A, B, and C are met during the first pass of rolling in step two, the mill will be stopped quickly, and rolling will end immediately. There is no need to perform subsequent judgments and controls in steps three and four, or in the second and third passes; 2) if step three determines that the billet head does not slip before passing the vertical roll in the second pass and rolling normally, then step four continues to determine whether the billet head slips after passing the vertical roll in the second pass and controls the mill to stop or roll normally; 3) if rolling is normal in step four, then the judgment and control for the third pass will continue according to step two, and finally rolling will end.
[0080] Example 2
[0081] The method for preventing steel pile-up in the roughing mill vertical and horizontal rolls of this embodiment, taking a roughing mill with three passes as an example, includes the following steps:
[0082] Step 1: Determine the rolling pass
[0083] Generally, vertical and horizontal rolling mills can perform reversible rolling, and are classified into odd-numbered and even-numbered passes based on the number of passes. In this embodiment, passes 1 and 3 are odd-numbered passes, and pass 2 is an even-numbered pass. During passes 1 and 3, the billet is first rolled by the vertical rolling mill and then by the horizontal rolling mill; during pass 2, the billet is first rolled by the horizontal rolling mill and then by the vertical rolling mill; at this time, the vertical rolling mill is generally unloaded.
[0084] Step 2: Perform deviation judgment and fast stop control for odd-numbered rolling passes.
[0085] First, the rolling process of the first pass is judged and controlled. The main risk of steel stacking in odd-numbered passes is that after the head exits the horizontal rolling mill, the steel stacking will be caused by impacting the side guide plate at the exit of the horizontal rolling mill.
[0086] 1) The physical quantities involved at this time are as follows:
[0087] The rolling force deviation D1 on both sides during horizontal rolling mill rolling is 30 tons;
[0088] The pressure sensor on the guide plate at the exit of the horizontal rolling mill detects a pressure f1 of 0.23 tons.
[0089] The horizontal rolling mill exit knockout image recognition detection device detects the knockout height Y1, which is 40 mm.
[0090] 2) Determine whether the following three conditions are met:
[0091] A. The absolute value of the difference between the maximum and minimum values of D1 is greater than 100 tons;
[0092] B.f1 > 20 tons;
[0093] C.Y1 > 800 mm;
[0094] If none of the above three conditions are met, normal rolling will proceed.
[0095] Step 3: Control the billet head before it passes the vertical roll in even-numbered rolling passes. Next, the billet head is judged and controlled before it passes the vertical roll in the second rolling pass. Since the billet passes through the horizontal roll first in even-numbered rolling passes, if the billet head slips or deviates before passing the vertical roll, the risk of the billet piling up between the vertical and horizontal roll mills is extremely high.
[0096] 1) The physical quantities involved at this time are:
[0097] The linear speed V2 of the horizontal roller rotation is 3.0 m / s;
[0098] The slip value before horizontal roll rolling is 1.06;
[0099] The center-to-center distance L2 between the vertical and horizontal rolling mills is 3 meters.
[0100] The actual rolling force F2 for rolling steel billets on a horizontal rolling mill is around 1900-2140 tons.
[0101] The predicted rolling force SF2 for rolling steel billets on a horizontal rolling mill is 2100 tons.
[0102] The deviation of rolling force on both sides, D2, during horizontal rolling mill rolling is about 10-30 tons;
[0103] 2) Slip recognition
[0104] Within the few seconds before the billet head passes the vertical roll, the maximum actual rolling force of the billet rolled by the horizontal roll mill is F2max, which is 2140 tons, and the minimum is F2min, which is 1900 tons. The following conditions must be considered:
[0105] (1) When F2max-SF2>600 tons, if (F2max-SF2)×0.4+SF2-F2min>1200 tons, then it is judged as rolling slippage;
[0106] (2) When F2max-SF2≤600 tons, if F2max-F2min>1200 tons, it is judged as rolling slippage;
[0107] (3) If neither of the above conditions (1) nor (2) is met, then the rolling process does not slip and the rolling is normal.
[0108] Since F2max-SF2=2140 tons-2100 tons=40 tons≤600 tons, and F2max-F2min=2140 tons-1900 tons=240 tons, conditions (1) and (2) are not met, it is judged that the strip steel rolling is not slipping and is rolled normally.
[0109] 3) When the deviation judgment and fast stop control record of the rolling force deviation D2 on both sides of the horizontal roll mill is generated from the start of the steel signal until the absolute value of the difference between F2 and SF2 is less than 600 tons and the duration exceeds seconds, the recording ends. During this time range, the maximum value of the rolling force deviation on both sides of the horizontal roll mill is D2max, which is 30 tons, and the minimum value is D2min, which is 10 tons.
[0110] Since the second pass does not meet the above conditions (1) or (2), and the difference between D2max and D2min is 30 tons - 10 tons = 20 tons < 100 tons, then normal rolling is performed.
[0111] Step 4: Controlling the billet head after it passes the vertical roll in even-numbered rolling passes. Next, we will judge and control the billet head after it passes the vertical roll in the second rolling pass. The risk of billet piling after the billet head passes the vertical roll in even-numbered rolling passes is mainly due to the impact of the side guide plate upstream of the vertical roll mill.
[0112] 1) The physical quantities involved at this time are:
[0113] The rolling force deviation D2 on both sides during horizontal rolling mill rolling is 10-150 tons.
[0114] The actual rolling force F2 for rolling steel billets on a horizontal rolling mill is 1800-2000 tons.
[0115] The predicted rolling force SF2 for rolling steel billets on a horizontal rolling mill is 2100 tons.
[0116] The pressure sensor on the upstream guide plate of the vertical rolling mill detects pressure f2, which is 30 tons.
[0117] The image recognition and detection device for the upstream knocking head of the vertical roll mill detects the knocking head height Y2, which is 1200 mm.
[0118] After the billet head passes the vertical roll, when the absolute value of the difference between F2 and SF2 is less than 600 tons and the duration exceeds seconds, D2 is recorded. D2 recording ends when the rolling mill throws the billet. The maximum value of D2 within this time range is D2max = 150 tons, and the minimum value of D2 is D2min = 10 tons.
[0119] Because the following three conditions are met simultaneously:
[0120] (4) The absolute value of the difference between D2max and D2min is greater than 100 tons;
[0121] (5) f2 > 20 tons;
[0122] (6) Y2 > 800 mm;
[0123] This triggers a rapid stop of the rolling mill, ending the rolling process.
[0124] Obviously, 1) if conditions A, B, and C are met during the first pass of rolling in step two, the mill will be stopped quickly, and the rolling will end immediately without the need for subsequent steps three and four, or for judging and controlling the second and third passes; 2) if step three determines that the billet head slips before passing the vertical roll during the second pass, the mill will be stopped quickly, and the rolling will end immediately without the need for subsequent steps three and four, or for judging and controlling the third pass; 3) if the rolling is normal in step four, the third pass will continue to be judged and controlled according to step two, and finally the rolling will end.
[0125] Rough rolling typically involves three passes. For rough rolling with fewer or more than three passes, the judgment and control methods provided in the above embodiments are also followed, i.e., the judgment and control methods remain unchanged.
[0126] The above description is only a preferred embodiment of the present invention, but the present invention is not limited thereto. All equivalent substitutions or modifications made to the concepts and technical solutions of the present invention should be covered within the protection scope of the present invention.
Claims
1. A method for preventing steel pile-up in roughing mills with vertical and horizontal rolls, characterized in that... Includes the following steps: Step 1: Determine the rolling pass The rolling passes are divided into odd-numbered passes and even-numbered passes. When rolling in odd-numbered passes, the billet is first rolled by a vertical roll mill and then by a horizontal roll mill. When rolling in even-numbered passes, the billet is first rolled by a horizontal roll mill and then by a vertical roll mill. Step 2: Perform deviation judgment and fast stop control for odd-numbered rolling passes. 1) The physical quantities involved in odd-numbered rolling processes include: The deviation of rolling force on both sides during rolling in a horizontal roll mill, D1, in tons; The pressure sensor on the exit side guide plate of the horizontal rolling mill detects pressure f1, in tons; The horizontal rolling mill exit knockout image recognition and detection device detects the knockout height Y1, in millimeters; 2) If all three of the following conditions are met simultaneously: A. The absolute value of the difference between the maximum and minimum values of D1 is greater than 100 tons; B.f1 > 20 tons; C.Y1 > 800 mm; If the rolling mill stops quickly, it will stop; otherwise, it will continue rolling normally. Step 3: Control the head of the billet before it passes the vertical roll in even-numbered rolling passes. 1) The physical quantities involved at this time are: The linear velocity of the horizontal roller, V2, is expressed in meters per second. Horizontal roll rolling forward slip value β; The center-to-center distance L2 between the vertical and horizontal rolling mills, in meters; The actual rolling force F2 for rolling steel billets on a horizontal roll mill, in tons; The predicted rolling force SF2 for steel billets rolled by a horizontal rolling mill, in tons; The deviation of rolling force on both sides during horizontal rolling mill rolling, D2, in tons; 2) Slip recognition Before the billet head passes the vertical roll Within the time frame, the maximum actual rolling force of the horizontal rolling mill for rolling steel billets is F2max, and the minimum is F2min, as determined below: (1) When F2max-SF2>600 tons, if (F2max-SF2)×0.4+SF2-F2min>1200 tons, then it is judged as rolling slippage; (2) When F2max-SF2≤600 tons, if F2max-F2min>1200 tons, it is judged as rolling slippage; (3) If neither of the above conditions (1) nor (2) is met, then the rolling process does not slip and the rolling is normal. 3) Pull-off detection and quick stop control Record the rolling force deviation D2 on both sides of the horizontal rolling mill from the time the steel signal is generated until the absolute value of the difference between F2 and SF2 is less than 600 tons and the duration exceeds [a certain value]. When the time interval is reached, the recording ends. Within this time range, the maximum value of the rolling force deviation between the two sides of the horizontal rolling mill is D2max, and the minimum value is D2min. If the above conditions (1) or (2) are met, and the difference between D2max and D2min is greater than 100 tons, then the mill will be stopped quickly; otherwise, rolling will proceed normally. Step 4: Control of the billet head after passing through the vertical rolls in even-numbered rolling passes. 1) The physical quantities involved at this time are: The deviation of rolling force on both sides during horizontal rolling mill rolling, D2, in tons; The actual rolling force F2 for rolling steel billets on a horizontal roll mill, in tons; The predicted rolling force SF2 for steel billets rolled by a horizontal rolling mill, in tons; The pressure sensor on the upstream guide plate of the vertical rolling mill detects pressure f2, in tons; The image recognition and detection device for the upstream knock-out head of the vertical roll mill detects the knock-out head height Y2, in millimeters. The duration of the billet head after passing through the vertical roll exceeds When the rolling mill throws out the steel, D2 is recorded from the beginning to the end. The maximum value of D2 within this time range is D2max, and the minimum value of D2 is D2min. If all three of the following conditions are met: (4) The absolute value of the difference between D2max and D2min is greater than 100 tons; (5) f2 > 20 tons; (6) Y2 > 800 mm; If the rolling mill stops quickly, it will stop; otherwise, it will continue rolling normally.