Improvement method for MRG speed of temper rolling of different steel types

Abstract

The invention belongs to the field of metallurgical industry automatic control, and relates to a method for improving the MRG speed of temper rolling of different steel grades, which is characterized by comprising the following steps of: 1, selecting supplied materials; 3, a temper mill brings in steel coil data from an uncoiler, a straightener straightens a steel plate, the temper mill selects a recoiling or leveling process mode, tension control is carried out on a feeding roller at an outlet, tension coiling of a coiling machine is completed, and trolley transportation is finished. When special steel varieties are rolled, L1 head and tail speed automatic adjustment control is input, the coil loosening phenomenon of a coiling machine is eliminated, the equipment failure time is saved, the problems of large gaps and scratches of steel coils are solved, the product surface qualification rate is increased, and good benefits are obtained. The method is suitable for being used in hot rolling leveling process control.

Description

Technical Field

[0001] The invention belongs to the field of automatic control in metallurgical industry, and is aimed at L1 control selection of different steel grades in leveling process without L2 model control, and relates to an improvement method for MRG speed of leveling rolling different steel grades. Background Art

[0002] The 2250mm leveling line is mainly used for leveling or re-winding the steel coils produced by the main rolling lines, including the 2250 line and the 1549 line, to improve the performance of the steel coils, improve the layer fault, tower shape and ductility of the steel coils, etc. It is an important supplement to the rolling line. With the development of special steel varieties and mixed rolling technology, according to the rolling process requirements, the L2 system of the leveling production line has no model control, and only the steel coil data obtained from the three-level communication. For different steel grades, the control is simple and refined management cannot be achieved. Especially when rolling T4003 or stainless steel thin materials, there is a loose coil phenomenon when the head and tail are coiled. This requires the optimization and improvement of the process from the L1 speed control to meet the needs of special steel grades.

[0003] The present invention aims at the L1 control selection of different steel grades in the leveling process without L2 model control, and automatically or manually selects MRG parameters according to the thickness of the incoming material and the steel grade, thereby ensuring a smooth connection from speed control to tension control, avoiding abnormal coil shape, and meeting the requirements of the coil process. Summary of the invention

[0004] The purpose of the present invention is to provide a method for improving the MRG speed of temper rolling different steel grades in view of the above problems.

[0005] The object of the present invention is achieved by: a method for improving the speed of temper rolling different steel grades MRG, characterized by comprising the following steps: step 1: material selection;

[0006] Step 3: The leveler brings in the coil data from the uncoiler, the straightener straightens the steel plate, the leveler selects the rewinding or leveling process mode, the outlet feed roller tension is controlled, the coiler tension coiling is completed, and the trolley transportation is completed.

[0007] The material required for step one is 3-4mm thick and 1100-2200mm wide.

[0008] The beneficial effects of the present invention are as follows: the present invention uses L1 head and tail speed automatic adjustment control when rolling special steel varieties, eliminates the phenomenon of coiling machine loose coil, saves equipment failure time, solves the problem of large coil gap and scratches, improves the surface qualification rate of products, and achieves good benefits. The present invention is suitable for use in hot rolling flattening process control.

[0009] 1. It makes up for the lack of L2 model control in the rear production line, and realizes automatic adjustment of changes in steel grades and specifications from the control perspective.

[0010] 2. It provides control possibilities for special steel grades and thin materials, as well as new steel grades to be added in the future, thus expanding the application scope of automatic control.

[0011] 3. Through the control of the head and tail roll speed, the qualified rate of the product is guaranteed, and the economic benefits achieved are about 1.1 million per year. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0013] According to the historical rolling records, the process of carbon steel, 300 series, and 400 series is summarized, and the coiling curves of different thickness steel coils are collected for analysis. T4003 or steel coils with a thickness of less than 4.0mm have loose coils at the head and tail, which corresponds to the two stages of coiling speed control. In the first stage, when the head of the strip passes through the end of the leveler, the strip must pass through the feed roller and be wound on the reel. In order to make the strip have a good running state before biting into the reel, the speed of the feed roller must be the speed of the strip out of the end of the leveler. In this way, there is a certain speed difference before and after the strip, which generates a certain tension, so that the strip can move forward well. At the same time, because the head of the strip passes through the feed roller before biting the steel at the reel, its speed is already the leading speed, that is, the set value of the reel speed must be the leveler speed plus a certain proportion of the leading rate. The leading rate is given by the control, and the speed control process ends when the strip is stretched out of the reel and a signal is generated. The second stage: when the tail of the strip passes through the end frame of the leveling machine, the coiler switches from tension control to speed control. At this time, since the tail of the strip has left the leveling machine, the tension between the tail of the strip and the reel must be provided by the speed difference, so as to maintain the good coiling of the tail of the strip. Since the reel provides a forward tension for the strip at this time, in order to keep the strip flat, a certain directional tension must be applied to the tail of the strip. In the speed control of this stage, the speed of the reel is consistent with the size when the strip switches from tension control to speed control, and the speed of the pinch roller lags behind this speed value. The specific lag rate is given by the control, and the speed difference between the reel and the pinch roller provides the required tension for the strip. As the coiling process proceeds, the speed of the strip gradually decreases until the strip is coiled. The tension control is normal, and the head and tail speed control cannot be perfectly connected with the tension control.

[0014] The specific solution to the problem is: 1. L1 control is divided into two PLC controls, S7-400 for equipment control, TDC for speed and tension control. First, add steel type selection buttons and thickness judgment selection blocks under S7-400 control, and add communication points with TDC to send it for speed control selection.

[0015] 2. TDC receives the selection signal sent by S7-400. When controlling the head and tail speeds of the coiler, ordinary steel grades use the original speed control. When rolling T4003 and steel grades with a thickness of less than 4.0 mm, the head and tail speed control is selected separately. The acceleration time of the coiling speed is changed in MRG, thereby changing the speed of the coiler.

[0016]

[0017] One is tension control, which is based on steel grade specifications or width and thickness. If the conditions are met, a control command is sent through the S7400 program. Then TDC uses MRG control to increase or decrease the tension between the straightening machine, leveling machine, pinch rollers, and coiling machine. The tension of thick and wide steel is increased by about 20KN to achieve smooth control of this steel grade.

[0018] The method for improving the MRG speed of temper rolling different steel grades includes the following steps: Step 1: Material selection: The material requires a thickness of 3-4 mm and a width of 1100-2200 mm;

[0019] If the incoming material thickness is greater than 4mm, it is controlled according to the original speed. The flattening machine is divided into two original line speed modes, a low-speed original speed of 300M / MIN, and a high-speed original speed of 600M / MIN. The flattening machine is used as the line speed benchmark, the uncoiler and the straightener are lagging control, the outlet pinch roller and the coiler are leading speed control, step three: the flattening machine brings in the steel coil data from the uncoiler, the straightener straightens the steel plate, the flattening machine selects the rewinding or flattening process mode, the outlet feed roller tension control, the coiler tension coiling is completed, and the trolley transportation is completed. Embodiment 1

[0020] During the threading process of the flattening production line, the steel coil specifications are judged. If it is T4003, the selection switch is 1, or the thickness judgment selection is less than 4.0mm steel coil, and a TDC signal will be sent to adopt a separate head and tail speed control method, that is, the coiler acceleration time is 1 reduced by 10%, and the pinch roller hysteresis rate is 0.986, thereby increasing the tension between the coiler and the pinch roller to ensure that there is no gap or loose coil in the steel coil; if it is ordinary steel or the thickness is greater than 4.0mm, the original head and tail speed parameters are used to ensure that different steel grades and thickness specifications can be stably produced.

[0021] In specific implementation, for example, in the coil data of the leveling uncoiler, if the width of the steel coil is greater than 1500mm, it is judged by S7-400 and sent to TDC as 1. Through MRG tension control, when it is 0, the tension is less than 150. When it is 1, the tension between the coiler and the leveling machine is increased to between 170-190, realizing classified tension control of steel coils of different widths, ensuring the improvement of the ductility performance of steel coils with larger widths.

[0022] For another example, when stainless steel grade T307 is leveled on the line, especially during the recoiling process, if both the steel grade T307 and the recoiling conditions are met, S7400 sends a control instruction to TDC, and controls the speed matching relationship between the straightener and the coiler through the MRG tension speed mode. Since there is no leveling machine involved, the lag rate of the straightener is 0.99 and the lead rate of the coiler is 1.01. The tension control of the steel plate between the straightener and the coiler is increased by speed changes, thereby ensuring that the coil is not loose and completing the perfect control of the recoiling process.

[0023] The above description is only a specific embodiment of the present invention, but the structural features of the protection scope of the present invention are not limited thereto. Any changes or modifications made by any technician in the field of the present invention are all covered by the patent scope of the present invention.

Claims

1. A method for improving the MRG speed of temper rolling different steel grades, characterized by: The following steps are involved: Step 1: Material selection; Step 3: The leveler brings in the coil data from the uncoiler, the straightener straightens the steel plate, the leveler selects the rewinding or leveling process mode, the outlet feed roller tension is controlled, the coiler tension coiling is completed, and the trolley transportation is completed.

2. The method for improving the speed of temper rolling different steel grades according to claim 1, characterized in that: The material required for step one is 3-4mm thick and 1100-2200mm wide.

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