A method for controlling the laminar cooling of a hot-rolled thin-gauge strip

Abstract

The application discloses a kind of hot-rolled thin gauge strip and its laminar cooling control method of starting to suit, method includes the following steps: S1, adjust the last stand transition plate height of finishing rolling;S2, control thin gauge strip heating target temperature of furnace;S3, rough rolling is carried out production organization using 1+5 mode, and after finishing rolling is completed, control rolling mill automatic speed reduction;S4, laminar cooling starts to supply water cooling strip by the 50th header.This application controls the speed of hot-rolled production line, equipment precision and laminar cooling time by reasonable control, thereby realizing the control of thin gauge strip laminar cooling starting to suit problem, and the number of rolls of laminar cooling starting to suit defect is greatly reduced by implementing relevant control technology, creating greater economic benefits, and the improvement effect is remarkable.

Description

Technical Field

[0001] This invention relates to the field of hot-rolled strip steel production in the metallurgical industry, and particularly to a method for controlling the laminar flow cooling and unwinding of hot-rolled thin strip steel. Background Technology

[0002] Layer cooling roll forming is a common production anomaly in the production of hot-rolled thin strip steel. Due to its thinness and high speed during production, thin strip steel will form a roll forming phenomenon on the layer cooling roller table when it is obstructed. Severe roll forming poses a significant risk of scrapping. At the same time, the roll forming location will form a folding defect due to the pressure of the coiler's pinch rolls. This not only affects the on-time delivery of products but also causes quality loss. Therefore, technical measures need to be taken to control it.

[0003] Currently, the main methods for controlling strip roll forming during laminar cooling are through optimized control of mill speed and roller table speed. For example, patent CN111992588A, "A Method for Controlling Strip Roll Forming During Laminar Cooling," dynamically monitors the laminar cooling roller table area after the finishing mill. When a forming phenomenon is detected, it automatically intervenes in the finishing mill stand speed to control the forming of strip rolls in subsequent rolling. Patent CN201110280742.0, "A Method for Eliminating Forming of Thin Strip on Laminar Cooling Roller Tables," eliminates the forming phenomenon of thin strip on laminar cooling roller tables by optimizing the laminar cooling roller table lead rate, optimizing the opening mode of the upper and lower manifolds in the laminar cooling mode, and optimizing the speed at which thin strip advances on the laminar cooling roller table.

[0004] However, the above solutions all lead to high costs. Therefore, considering the actual situation of hot rolling production lines, it is of great significance to develop a method that can simply and effectively control the cold rolling of hot-rolled thin strip without increasing costs, based on the comprehensive control of four aspects: speed, equipment precision, and laminar cooling. Summary of the Invention

[0005] The main objective of this invention is to provide a control method for hot-rolled thin strip steel and its laminar flow cooling sleeve removal. By reasonably controlling the speed of the hot rolling production line, the equipment precision, and the laminar flow cooling time, the problem of laminar flow cooling sleeve removal of thin strip steel can be controlled.

[0006] According to one aspect of the present invention, a method for controlling the laminar flow cooling sleeve of hot-rolled thin strip steel is provided, comprising the following steps:

[0007] S1. Adjust the height of the transition plate of the finishing mill stand;

[0008] S2. Control the target temperature for heating thin-gauge strip steel before it exits the furnace;

[0009] S3. Roughing is organized in a 1+5 mode for production, and after finishing rolling is completed, the mill speed is automatically reduced.

[0010] S4, laminar cooling starts from the 50th header to cool the strip.

[0011] According to one embodiment of the present application, in step S1, the transition plate height is controlled to be lower than the rolling level by 10±5 mm.

[0012] According to one embodiment of the present application, in step S2, the thin-gauge strip is controlled to have a heating discharge target temperature of 1250±20°C.

[0013] According to one embodiment of the present application, in step S2, the front and rear transition materials are controlled to have a discharge temperature target temperature of 1250±20°C.

[0014] According to one embodiment of the present application, in step S3, high-speed rolling is used in each pass.

[0015] According to one embodiment of the present application, in step S3, the rolling mill is controlled to automatically reduce the rolling speed by 0.1 m / s.

[0016] According to one embodiment of the present application, in step S3, after the automatic reduction reaches the reduction time, the rolling mill is controlled to normally increase the speed.

[0017] According to another aspect of the present application, a hot-rolled thin-gauge strip is provided, which is manufactured by the method according to any one of the above technical solutions.

[0018] In the control method for the hot-rolled thin-gauge strip and the laminar cooling start-up according to the embodiments of the present application, the speed of the hot-rolling production line, the equipment precision and the laminar cooling time are reasonably controlled, so as to control the laminar cooling start-up problem of the thin-gauge strip. Through the implementation of the relevant control technology, the number of laminar cooling start-up defect coils is greatly reduced, great economic benefits are created, and the improvement effect is remarkable. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required by the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 A process flow chart of a control method for the laminar cooling start-up of a hot-rolled thin-gauge strip according to one exemplary embodiment of the present application is shown;

[0021] Figure 2 A comparison chart of the improvement effect after the implementation of the control method for the laminar cooling start-up of a hot-rolled thin-gauge strip according to one exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0022] In order to make the objects, technical solutions and advantages of the present application clearer, the embodiments of the present application are further described in detail below with reference to the drawings.

[0023] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0024] As shown in Figure 1 The present application provides a control method for hot rolling thin gauge strip steel laminar cooling start-up, which comprises the following steps:

[0025] S1, adjusting the transition plate height of the last stand of finishing rolling;

[0026] S2, controlling the target temperature of thin gauge strip steel heating and leaving the furnace;

[0027] S3, using 1+5 mode for production organization in rough rolling, and controlling the rolling mill to automatically reduce speed after completing the strip passing;

[0028] S4, laminar cooling starts to supply water to cool the strip steel from the 50th header.

[0029] In the control method for hot rolling thin gauge strip steel laminar cooling start-up according to the embodiments of the present application, the speed of the hot rolling production line, the equipment precision and the laminar cooling time are reasonably controlled, thereby realizing the control of the laminar cooling start-up problem of thin gauge strip steel, the number of laminar cooling start-up defect coils is greatly reduced through the implementation of relevant control technologies, great economic benefits are created, and the improvement effect is remarkable.

[0030] In step S1, the transition plate height is controlled to be lower than the rolling level line by 10±5mm. The adjustment of the transition plate height can ensure that the strip steel head smoothly passes through the wear plate part and smoothly transitions to the next stand for rolling, thereby eliminating the occurrence of scrap steel at this part.

[0031] In step S2, the target temperature of thin gauge strip steel heating and leaving the furnace is controlled to be 1250±20℃, which can realize more accurate control of the leaving temperature.

[0032] In step S2, the target temperature of the front and rear transition material leaving the furnace is controlled to be 1250±20℃.

[0033] In step S3, high-speed rolling is used in each pass. High-speed rolling can improve rolling efficiency and save production time.

[0034] The 1+5 mode means that R1 rolls 1 pass and R2 rolls 5 passes.

[0035] The rolling mill is automatically reduced to a rolling speed of 0.1 m / s to meet the speed requirements of the rolling line production rhythm.

[0036] In step S3, after the automatic speed reduction reaches the reduction time, the rolling mill resumes normal speed increase.

[0037] In some specific embodiments, a mill speed reduction window is added to the finishing rolling process control screen. The input in this window is time (unit: seconds). After the time is input, the mill automatically reduces its speed according to the rolling speed of 0.1m / s. After the speed reduction time is reached, the mill resumes normal speed increase.

[0038] like Figure 2 As shown, the problem of layer cooling roll forming in the hot rolling production line was controlled. By implementing the relevant control technology mentioned in this invention, the number of defective coils due to layer cooling roll forming was reduced from 23.4 coils / month to 10 coils / month, creating significant economic benefits and demonstrating remarkable improvement.

[0039] The present invention also provides a hot-rolled thin strip steel, which is rolled using the method mentioned in the above technical solution.

[0040] This invention addresses the issue of cold roll forming in thin strip steel by rationally controlling the speed, equipment precision, and laminar cooling time of the hot rolling production line. Through the implementation of relevant control technologies, the number of coils with cold roll forming defects is significantly reduced, resulting in substantial economic benefits and a remarkable improvement effect.

[0041] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular.

[0042] Those skilled in the art should understand that the above discussion of any embodiment is only exemplary, and is not intended to mean that the scope of the embodiments disclosed by the present application (including claims) is limited to these examples; under the idea of the embodiments of the present application, the above embodiments or technical features among different embodiments can also be combined, and there are many other changes of different aspects of the embodiments of the present application as described above, which are not provided in details for the sake of brevity. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present application shall be included in the protection scope of the embodiments of the present application.

Claims

1. A method for controlling the laminar flow cooling and shearing of hot-rolled thin strip steel, characterized in that, Includes the following steps: S1. Adjust the height of the transition plate of the finishing mill stand, and control the height of the transition plate to be 10±5mm lower than the rolling horizontal line; S2. Control the target temperature of the thin strip steel when it is heated and exited from the furnace. The target temperature of the thin strip steel when it is heated and exited from the furnace is 1250±20℃. The target temperature of the transition materials before and after the furnace is also 1250±20℃. S3. Roughing is organized in a 1+5 mode. After finishing rolling is completed and the strip is threaded, the mill is automatically reduced in speed. The 1+5 mode means that R1 is rolled in 1 pass and R2 is rolled in 5 passes. S4. Laminar flow cooling starts from the 50th manifold to cool the strip steel.

2. The control method for laminar flow cooling of hot-rolled thin strip steel according to claim 1, characterized in that, In step S3, high-speed rolling is used in each pass.

3. The control method for laminar flow cooling of hot-rolled thin strip steel according to claim 1, characterized in that, In step S3, the rolling mill is controlled to automatically reduce its speed according to the rolling speed of 0.1 m / s.

4. The control method for laminar flow cooling of hot-rolled thin strip steel according to claim 3, characterized in that, In step S3, after the automatic speed reduction reaches the reduction time, the rolling mill resumes normal speed increase.

5. A hot-rolled thin strip steel, characterized in that, It is made by using the method described in any one of claims 1-4 above.

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