A kind of flat roller control method for prolonging free rolling mileage
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI MEISHAN IRON & STEEL CO LTD
- Filing Date
- 2024-11-29
- Publication Date
- 2026-06-05
AI Technical Summary
In existing technologies, the working rolls in the finishing area of hot rolling production lines are numerous and uneven, resulting in wasted roll consumption and uneven roll wear. Especially in the free rolling process, the roll wear problem becomes prominent after the rolls are standardized, affecting the quality of the strip cross-section.
By adopting a flat roll control method, and through the calculation formula of roll position and the judgment of width limit, roll movement control for different finishing mill races, thickness grades and furnace conditions can be achieved, roll wear can be uniformly distributed, and the free rolling mileage can be extended.
It effectively reduces roll wear, minimizes strip cross-section degradation, increases planned unit weight, extends free rolling mileage, and improves production efficiency.
Abstract
Description
Technical Field
[0001] This invention relates to a method for controlling flat rolls to extend the number of kilometers of free rolling, belonging to the field of hot continuous rolling production technology. Background Technology
[0002] There are currently four types of work rolls in the finishing area of the hot rolling production line: F0 large diameter flat roll, F1~F3 are CVC2 rolls, F4 and F5 stands are PARA flat rolls, and F6 stand is CVC1 roll. The problem of multiple stands and multiple roll types in the finishing area is gradually emerging: (1) The finishing mill stands F4, F5 and F6 are composed of two different roll types of the same material (infinitely cold hardened roll). In the process of reversing rolls in the grinding workshop, if the CVC roll type of F6 stand is reversed to F4 or F5 stand for use, the original CVC roll type needs to be ground flat and then re-opened as a flat roll, resulting in a waste of roll wear; (2) The CVC1 roll type of finishing mill F6 stand has a positive and negative crossover ratio of about 85% and 15% in one rolling cycle. The utilization rate of the negative crossover position of the roll is low, and the positive crossover position also has the problem of severe local wear. With the continuous increase of the direct loading and direct rolling ratio of the hot rolling production line, the problem of reversing rolls caused by multiple roll types is prominent. With the continuous increase in free rolling mileage and the standardization of finishing roll profiles, the issue of how to even out roll wear and improve strip cross-section has become more urgent. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the above-mentioned technologies and provide a flat roll control method that can extend the free rolling kilometer.
[0004] To solve the above-mentioned technical problems, the technical solution proposed by this invention is: a method for controlling a flat roll to extend the free rolling mileage, comprising the following steps: (1) Based on the current strip tapping mark and finished product specifications, read the roll configuration enable switch of each stand of the finishing mill corresponding to the type and thickness grade; if the roll configuration enable switch is enabled, proceed to the next step; (2) Read the relevant data of the upper strip; read the adjustment direction variable of the upper strip roll, the position of the roll of each stand, the activation switch of the new roll configuration of each stand, and the furnace number; (3) Determination of single-furnace and multi-furnace identification: The heating furnace number of the current strip steel is compared with the heating furnace number of the previous strip steel. If they match, a single-furnace identification will be set; otherwise, a multi-furnace identification will be set. (4) Read the current strip roll configuration data; based on the current strip tapping mark and finished product specifications, read the corresponding race, thickness grade, and single / multi-heater identifier, and read the corresponding race, thickness grade, single / multi-heater maximum roll limit, minimum roll limit, step length, and roll disturbance amount; (5) Calculation of the position of the shifting roller; The formula for calculating the position of the shifting roller is as follows: Loc[i] = PreLoc[i] + Loc_step[i] * shift_dir[i] * Premod[i] - Loc_step_lim[i], where: i is the position index of each stand in the finishing mill, represented by the value 0-6; Loc[i] is the current roll shifting position of each stand in the strip finishing mill; PreLoc[i] is the roll shifting position of each stand in the previous strip finishing mill; Loc_step[i] is the configured roll shifting step size of each stand in the finishing mill; shift_dir[i] is the roll shifting adjustment direction of each stand in the previous strip finishing mill; Premod[i] is the roll shifting configuration enable / disable switch configuration of each stand in the previous strip finishing mill; Loc_step_lim[i] is the roll shifting disturbance amount of each stand in the current strip finishing mill.
[0005] The further improvement of the above scheme is that: before step (1), there is also a start determination; if the roll shifting and bending rolls are put into automatic mode, and the finishing roll type is not a flat roll, and the number of rolling blocks exceeds the threshold, then the flat roll control method is started.
[0006] The further improvement of the above scheme is that: after step (5), there is also step (6) for judging the position limit of the skewed roller and adjusting the direction; whether the calculated position of the skewed roller is within the maximum and minimum limit range of the skewed roller in the current mode; if it exceeds the maximum limit of the skewed roller, the configured maximum limit of the skewed roller is used as the current position of the skewed roller, and the direction of the skewed roller is adjusted at the same time; if it is smaller than the minimum limit of the skewed roller, the configured minimum limit of the skewed roller is used as the current position of the skewed roller, and the direction of the skewed roller is adjusted at the same time.
[0007] A further improvement to the above scheme is that, after step (6), there is also step (7) for saving the flat roller control data; specifically, this includes, (7a) Save the variable of the direction of the roller shifting; the initial value of the direction of the roller shifting controlled by the flat roller is given as 1 by default, that is, the model first adjusts the position of the roller shifting in the positive direction at the current position of the roller shifting; until the positive position of the roller shifting reaches the configured maximum limit of the roller shifting, the direction of the roller shifting is given as -1; when the negative position of the roller shifting reaches the configured minimum limit of the roller shifting, the direction of the roller shifting is given as 1. (7b) Save the current roll positions of each strip mill stand; (7c) Save the current configuration of the roll shifting switch for each type of flat roll control on the strip mill; (7d) Save the current heating furnace number of the strip steel.
[0008] The present invention provides a method for controlling the length of free rolling in a flat roll-like manner, which innovates upon the flat roll shifting model. It realizes the roll shifting control strategy for different finishing mill types, thickness grades, furnace conditions, and stands. It enables the setting and control of the maximum and minimum limits of roll shifting, the roll shifting step size, and the roll shifting disturbance amount in single-furnace / multi-furnace modes for the same finishing mill type and thickness grade. It can better uniformly wear the rolls of each finishing mill stand, reduce roll consumption, and reduce strip cross-sectional degradation. It can effectively increase the planned unit weight and extend the length of free rolling. Detailed Implementation
[0009] Example: The method for extending the free rolling mileage in this example is based on AP1360C3 with a length of 4.0*1255 produced by a steel long hot continuous rolling production line on October 23, 2023. A method for extending the free rolling mileage is applied.
[0010] In this case: 1. When the finishing mill roll shifting and bending rolls are in automatic mode, and the finishing mill F6 (last stand) roll type is CVC roll type, and the number of rolled blocks exceeds 6, then the flat roll control method should be activated.
[0011] 2. Based on the current strip tapping mark AP1360C3 and finished product specification 4.0*1255, read the roll configuration enable switches [0,0,0,0,0,0,1] for the seven stands of the finishing mill with corresponding grade 3 and thickness 308. If the roll configuration enable switch for the 7th stand is 1, it indicates that the process requires the use of the flat roll control method of this embodiment.
[0012] 3. Read the roll adjustment direction variable of the upper strip [0,0,0,0,0,0,1], the roll position of the seven stands [0,0,-25.81,37.18,75.18,-75.28,57.83], the roll configuration enable switch of the new model of the seven stands [0,0,0,0,0,0,1], and save the heating furnace number 1.
[0013] 4. The current heating furnace number of the strip is 2, which is different from the heating furnace number 1 of the previous strip. The multi-furnace indicator is set to 1.
[0014] 5. Read the current strip roll configuration data. Based on the current strip's tap mark AP1360C3, finished product specification 4.0*1255, and multi-heat identifier 1, read the current strip's multi-heat roll configuration enable switch [0,0,0,0,0,0,1], multi-heat roll maximum limit [95,95,95,95,30,30,70], multi-heat roll minimum limit [-95,-95,-95,-95,-30,-30,10], multi-heat step size [0,0,0,0,13,13,17], and multi-heat roll disturbance amount [0,0,0,0,0,0,1].
[0015] 6. Based on the above-read setting data, calculate the roll shifting position. The roll shifting disturbance amount for finishing mill F6 (last stand) is 1. Therefore, the formula for calculating the roll shifting position is as follows: Loc[6]=PreLoc[6]+Loc_step[6]*shift_dir[6]*Premod[6]-Loc_step_lim[6]=57.83+17*1*1-1=73.83.
[0016] 7. The calculated roll shifting position of finishing mill F6 (last stand) is 74.83, which exceeds the range between [10, 70] of finishing mill F6 (last stand). Since 74.83 > 70, the calculated roll shifting position exceeds the maximum roll shifting limit. Therefore, the configured maximum roll shifting limit of 70 is used as the current roll shifting position. At the same time, the roll shifting direction variable is adjusted to -1.
[0017] 8. Save the variable for adjusting the direction of the roll shifting, save the current roll shifting position of each stand of the strip mill, save the roll shifting enable / disable switch configuration of the current flat roll control for each stand of the strip mill, and save the current heating furnace number of the strip mill.
[0018] This invention is not limited to the products described above. All technical solutions derived using equivalent substitutions fall within the scope of protection claimed by this invention.
Claims
1. A method for controlling a type of flat roll to extend the number of free rolling kilometers, characterized in that, Includes the following steps: (1) Based on the current strip steel tapping mark and finished product specifications, read the roll configuration activation switch of each stand of the finishing mill corresponding to the type and thickness grade; If the roller shifting configuration enable switch is enabled, proceed to the next step; (2) Read the relevant data of the upper strip; read the adjustment direction variable of the upper strip roll, the position of the roll of each stand, the activation switch of the new roll configuration of each stand, and the furnace number; (3) Determination of single-furnace and multi-furnace identification: The heating furnace number of the current strip steel is compared with the heating furnace number of the previous strip steel. If they match, a single-furnace identification will be set; otherwise, a multi-furnace identification will be set. (4) Read the current strip roll configuration data; based on the current strip tapping mark and finished product specifications, read the corresponding race, thickness grade, and single / multi-heater identifier, and read the corresponding race, thickness grade, single / multi-heater maximum roll limit, minimum roll limit, step length, and roll disturbance amount; (5) Calculation of the position of the shifting roller; The formula for calculating the position of the shifting roller is as follows: Loc[i] = PreLoc[i] + Loc_step[i] * shift_dir[i] * Premod[i] - Loc_step_lim[i], where: i is the position index of each stand in the finishing mill, represented by the value 0-6; Loc[i] is the current roll shifting position of each stand in the strip finishing mill; PreLoc[i] is the roll shifting position of each stand in the previous strip finishing mill; Loc_step[i] is the configured roll shifting step size of each stand in the finishing mill; shift_dir[i] is the roll shifting adjustment direction of each stand in the previous strip finishing mill; Premod[i] is the roll shifting configuration enable / disable switch configuration of each stand in the previous strip finishing mill; Loc_step_lim[i] is the roll shifting disturbance amount of each stand in the current strip finishing mill.
2. The method for controlling the length of free rolling kilometers according to claim 1, characterized in that: Before step (1), there is also a start determination; if the roll shifting and bending rolls are put into automatic mode, and the finishing roll type is not a flat roll, and the number of rolling blocks exceeds the threshold, then the flat roll control method is started.
3. The method for controlling the length of free rolling kilometers according to claim 1, characterized in that: After step (5), there is also step (6) for determining the position limit of the skewed roller and adjusting its direction; whether the calculated position of the skewed roller is within the maximum and minimum limit range of the skewed roller in the current mode; if it exceeds the maximum limit of the skewed roller, the configured maximum limit of the skewed roller is used as the current position of the skewed roller, and the direction of the skewed roller is adjusted at the same time; if it is smaller than the minimum limit of the skewed roller, the configured minimum limit of the skewed roller is used as the current position of the skewed roller, and the direction of the skewed roller is adjusted at the same time.
4. The method for controlling the length of free rolling kilometers according to claim 31, characterized in that: Following step (6), there is also step (7) for saving the flat roller control data; specifically including, (7a) Save the variable of the direction of the roller shifting; the initial value of the direction of the roller shifting controlled by the flat roller is given as 1 by default, that is, the model first adjusts the position of the roller shifting in the positive direction at the current position of the roller shifting; until the positive position of the roller shifting reaches the configured maximum limit of the roller shifting, the direction of the roller shifting is given as -1; when the negative position of the roller shifting reaches the configured minimum limit of the roller shifting, the direction of the roller shifting is given as 1. (7b) Save the current roll positions of each strip mill stand; (7c) Save the current configuration of the roll shifting switch for each type of flat roll control on the strip mill; (7d) Save the current heating furnace number of the strip steel.