Control method for solving camber in rough rolling process of hot rolling process

Abstract

The invention discloses a control method for solving camber in the rough rolling process of a hot rolling procedure, which belongs to the technical field of hot continuous rolling and comprises the following steps of: controlling the centering deviation of a rough rolling inlet side guide plate and a rough rolling outlet side guide plate within a threshold range; a short stroke function is added to a rough rolling inlet side guide plate; when the camber direction is the operation side, the stroke of the HWC cylinder on the transmission side is increased, so that the center line of the vertical roll deviates to the transmission side; when the camber direction is the transmission side, the stroke of the HWC cylinder on the operation side is increased, so that the center line of the vertical roll deviates to the operation side; when the camber direction is the operation side, a lining plate is additionally arranged at the transmission side outlet position or the operation side inlet position of a rough rolling upper roller; and when the camber direction is the transmission side, a lining plate is additionally arranged at the transmission side inlet position or the operation side outlet position of the rough rolling upper roller. According to the method, the camber defect can be effectively treated and corrected.

Description

Technical Field

[0001] The invention belongs to the technical field of hot rolling, and in particular relates to a control method for solving the problem of sickle bending in the rough rolling process of a hot rolling procedure. Background Art

[0002] During the plate shape control process in the rough rolling area of ​​hot rolling, the main focus is on adjusting the wedge and sickle bend of the intermediate billet. Since the thickness of the intermediate billet is usually above 25 mm, no wave-shaped defects will occur. However, the wedge and sickle bend defects in the rough rolling process are identified by manual visual inspection on site. Once plate shape defects appear in the rough rolling process, these defects cannot be completely eliminated in the subsequent rolling processes, which will have a greater impact on the subsequent finishing process. Since the thickness of the head and tail and both sides of the body of the intermediate billet are inconsistent with the center line, the final product will also have plate shape defects such as head and tail sickle bend and wedge shape. In severe cases, this will lead to a decrease in rolling stability in the finishing process, and may even cause undesirable phenomena such as scrap.

[0003] Normally, the wedge and camber defects of the intermediate billet appear at the same time. The camber is caused by the uneven pressing on both sides of the strip, which causes the strip to always bend toward the thicker side. Therefore, by performing online leveling on the rolling mill to eliminate the thickness difference on both sides, that is, eliminating the wedge of the strip, the camber will automatically disappear.

[0004] In the actual production process, especially in the first pass of rough rolling, the intermediate billet often bends toward the thinner side. This is because when the vertical rollers throw steel during the first pass of rough rolling, the intermediate billet loses the force of the vertical rollers, resulting in obvious swing and oblique movement of the strip. This movement direction does not completely match the rolling line, but forms a certain angle, causing the strip to deviate to the transmission side or the operating side. This deviation will cause serious sickle camber defects, and cannot be corrected by online leveling of the rolling mill. This phenomenon is different from the causes and phenomena of conventional plate shape defects.

[0005] The main reason for this phenomenon is that the center lines of the upper and lower working rolls cross during the rolling process due to uneven wear of the arch lining or the working roll bearing box lining. The fundamental solution to this problem is to accurately measure the centering and symmetry accuracy of the rolls, transmission shafts, frame arches and other equipment, and thoroughly repair and treat the arch wear to ensure that the upper and lower rolls do not cross and the roll axis is perpendicular to the rolling line. This solution process requires the use of professional measuring instruments for measurement and takes a long time, generally more than 24 hours. Therefore, it is usually organized during the annual maintenance of the rolling line to ensure accurate adjustment and repair of the equipment. Summary of the invention

[0006] The present invention aims to solve the technical problems existing in the known technology and provides a control method for solving the sickle camber occurring during the rough rolling process of the hot rolling process, so as to control the sickle camber defect of the rough rolling intermediate billet without affecting the normal production of the rolling line.

[0007] The object of the present invention is to provide a control method for solving the problem of camber in the rough rolling process of hot rolling process, comprising:

[0008] Control the deviation of the centering degree of the guide plate on the rough rolling inlet side and the guide plate on the outlet side within the threshold range;

[0009] Add short stroke function to the guide plate on the rough rolling entrance side;

[0010] Asymmetrical control of the HWC cylinder of the vertical roller: when the sickle bend direction is the operating side, increase the stroke of the HWC cylinder on the transmission side to make the center line of the vertical roller deviate to the transmission side; when the sickle bend direction is the transmission side, increase the stroke of the HWC cylinder on the operating side to make the center line of the vertical roller deviate to the operating side;

[0011] Adjust the gap between the lining plates of the roughing mill frame: when the sickle bend direction is the operating side, add a lining plate at the exit position of the roughing upper roller transmission side or the entrance position of the operating side; when the sickle bend direction is the transmission side, add a lining plate at the entrance position of the roughing upper roller transmission side or the exit position of the operating side.

[0012] Preferably, the short-stroke function is added to the guide plate on the rough rolling inlet side as follows: before the slab enters the vertical roller, the guide plate on the inlet side is used to support the slab to ensure the centering of the slab when entering the vertical roller.

[0013] Preferably, the thickness of the liner is determined according to the actual measured dimensions of the arch and the working roll bearing box.

[0014] Preferably, the deviation of the centering of the guide plate on the rough rolling inlet side and the guide plate on the outlet side is controlled within a range of no more than 5 mm.

[0015] The advantages and positive effects of the present invention are:

[0016] By using the advanced technical solution proposed in the present invention, the equipment can be accurately adjusted according to the specific direction of the sickle bend of the rough rolling intermediate billet. This process will not have any negative impact on the normal production activities of the rolling line, so that the sickle bend defect can be effectively treated and corrected without affecting the production efficiency. Through this method, the degree of defects can be significantly reduced, the production interruption time caused by equipment failure can be reduced, and long-term accident downtime can be avoided, ensuring the stable operation of the production line and maximizing production efficiency. DETAILED DESCRIPTION

[0017] In order to make the above-mentioned purpose and design advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] The technical solution of the present invention is:

[0019] A control method for solving the problem of camber in the rough rolling process of a hot rolling process, comprising:

[0020] The centering of the guide plate at the entrance and exit of the rough rolling mill must be controlled within a deviation range of ≤5mm; In order to ensure the normal operation of the rough rolling mill and the accurate processing of the slab, the centering of the guide plate at the entrance and exit of the rough rolling mill must be controlled within a deviation range of ≤5mm. This means that during the production process, the centering of the guide plate must reach extremely high accuracy to avoid any factors that may cause deviation in slab processing.

[0021] In addition, the rough rolling entrance side guide plate has a short stroke function. This function is to effectively support the slab through the entrance side guide plate before the slab enters the vertical roller. This ensures that the slab has good centering when entering the vertical roller, thereby improving the accuracy and quality of slab processing.

[0022] In order to further optimize the working performance of the vertical roller, the vertical roller HWC cylinder is asymmetrically controlled. Specifically, when the sickle bend is in the operating side, the stroke of the HWC cylinder on the transmission side will be appropriately increased, so that the center line of the vertical roller is biased toward the transmission side. On the contrary, when the sickle bend is in the transmission side, the stroke of the HWC cylinder on the operating side will be appropriately increased, so that the center line of the vertical roller is biased toward the operating side. This asymmetric control can effectively deal with sickle bend problems in different directions, ensuring that the vertical roller can maintain the best working condition under various conditions.

[0023] Finally, the gap between the liner and the arch of the roughing mill stand was adjusted. When the sickle bend is in the operating side, a liner is added at the exit position of the roughing upper roll drive side or the entrance position of the operating side. When the sickle bend is in the driving side, a liner is added at the entrance position of the roughing upper roll drive side or the exit position of the operating side. The thickness of the liner is determined based on the actual measured dimensions of the arch and the work roll bearing box to ensure that the gap between the liner and the stand is optimal, thereby improving the overall performance of the roughing mill and the accuracy of slab processing.

[0024] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A control method for solving the problem of camber in the rough rolling process of hot rolling process, characterized in that: include: Control the deviation of the centering degree of the guide plate on the rough rolling inlet side and the guide plate on the outlet side within the threshold range; Add short stroke function to the guide plate on the rough rolling entrance side; Asymmetrical control of the HWC cylinder of the vertical roller: when the sickle bend direction is the operating side, increase the stroke of the HWC cylinder on the transmission side to make the center line of the vertical roller deviate to the transmission side; when the sickle bend direction is the transmission side, increase the stroke of the HWC cylinder on the operating side to make the center line of the vertical roller deviate to the operating side; Adjust the gap between the lining plates of the roughing mill frame: when the sickle bend direction is the operating side, add a lining plate at the exit position of the roughing upper roller transmission side or the entrance position of the operating side; when the sickle bend direction is the transmission side, add a lining plate at the entrance position of the roughing upper roller transmission side or the exit position of the operating side.

2. The control method for solving the problem of camber in the rough rolling process of hot rolling process according to claim 1 is characterized in that: The short-stroke function added to the guide plate on the rough rolling inlet side is specifically: before the slab enters the vertical roller, the slab is supported by the guide plate on the inlet side to ensure the centering of the slab when entering the vertical roller.

3. The control method for solving the problem of camber in the rough rolling process of hot rolling process according to claim 1 is characterized in that: The thickness of the liner is determined according to the actual measured dimensions of the arch and the working roll bearing box.

4. The control method for solving the problem of camber in the rough rolling process of hot rolling process according to claim 1 is characterized in that: The deviation of the centering of the guide plate on the rough rolling inlet side and the guide plate on the outlet side is controlled within a range not exceeding 5mm.