A rough rolling roll setting method for controlling camber of a plate

Abstract

A rough rolling roll matching method for controlling plate camber of medium plate, in the process of medium plate rolling, the upper work roll and the lower work roll of the transverse spreading process in the rough rolling stage are subjected to grinding treatment by using the finishing rolls after the finishing stage, so that the two ends form a conical surface with a set taper, and the roll shapes of the upper work roll and the lower work roll are consistent after the grinding treatment. Through the optimization of the roll shape of the rough work roll, the present application realizes the increase of the middle transverse extension in the blank transverse rolling spreading stage, and weakens the width difference of the head and tail and the waist of the steel plate in the longitudinal rolling process, thereby avoiding the problem of excessive plate camber of the steel plate product. Meanwhile, the present application uses the finishing rolls after the finishing stage to obtain the rough work roll meeting the requirements through grinding treatment, and achieves the purpose of reducing the production cost.

Description

Technical Field

[0001] This invention relates to the field of steel rolling technology, specifically to a method for controlling the sickle-shaped profile of roughing mill rolls. Background Technology

[0002] The sickle-shaped profile of medium-thick plates refers to the lateral bending of the steel plate on a horizontal plane, resulting in a shape resembling a sickle (see appendix). Figure 1 The camber (indicated by label W, which represents the sickle curve of steel plate 1) is mainly caused by uneven extension in the width direction during the rolling process. Factors contributing to this problem include deviation of the roll gap on both sides during rolling, differences in stiffness between the two sides of the mill's arches, roll profile deviation and uneven roll wear, and abnormal alignment of the mill's pusher. Currently, the following methods are commonly used to control the camber shape of medium and heavy plates: 1. Dynamically adjust the hydraulic AGC system of the finishing mill, monitor the rolling force and roll gap on both sides in real time, and manually adjust and compensate for the roll gap to ensure that the deformation on the transmission side and the operating side of the steel plate is the same; 2. Regularly maintain the equipment to ensure the stiffness on both sides of the mill; 3. Regularly calibrate the reduction sensor to ensure accurate reduction adjustment; 4. Regularly replace the mill's support rolls and work rolls.

[0003] The aforementioned methods for controlling the sickle-shaped plate shape of medium and heavy plates are all achieved through strict implementation of production process management systems. However, without substantial innovation and improvement in the process, it is difficult to fundamentally improve the sickle-shaped plate shape problem during the rolling process of medium and heavy plates. Summary of the Invention

[0004] This invention provides a roughing roll allocation method for controlling the sickle-shaped profile of medium-thick plates. The aim is to increase the transverse extension in the middle of the billet during the transverse rolling widening stage by optimizing the roll shape of the roughing rolls, thereby reducing the width difference between the head, tail, and waist of the steel plate in the longitudinal rolling process, thus avoiding the problem of excessive sickle-shaped profile of the steel plate products. At the same time, the finishing rolls after the mill are used to obtain roughing rolls that meet the requirements through grinding, thereby reducing production costs.

[0005] To solve the above-mentioned technical problems and reduce production costs, the present invention adopts the following technical solution: A method for controlling the sickle-shaped profile of medium-thick plates in roughing rolling involves using the finishing rolls from the finishing rolling stage after the finishing rolling process to grind the upper and lower work rolls of the laterally widening process in the roughing rolling stage. This grinds the rolls to form conical surfaces with a set taper at both ends, ensuring that the rolls of the upper and lower work rolls have the same profile after grinding.

[0006] The above-mentioned roughing roll matching method for controlling the sickle-shaped plate shape of medium and heavy plates uses a CNC grinding machine to perform grinding operations on the upper and lower work rolls. According to the steel plate products of different sizes and specifications, the finishing rolls after the machine with the corresponding length and diameter are selected as grinding workpieces. They are hoisted onto the worktable of the CNC grinding machine, the position of the bearing bush of the CNC grinding machine is adjusted to ensure that the roll body of the workpiece is in a horizontal state, and the positioning and clamping of the workpiece is completed.

[0007] The above-mentioned roughing roll matching method for controlling the sickle-shaped plate of medium and heavy plates involves grinding the upper and lower work rolls. First, the Taper curve trajectory set by the CNC grinding machine control system is called to grind one end of the workpiece. After machining a tapered conical surface at one end of the roll, the Sine curve trajectory set by the CNC grinding machine control system is called to make the grinding wheel move idle. After the grinding wheel has completed the idle movement of the middle section of the roll body, the Taper curve trajectory set by the CNC grinding machine control system is called again to grind the tapered conical surface at the other end of the workpiece.

[0008] The roughing roll matching method described above for controlling the sickle-shaped plate of medium and heavy plates adopts a constant current automatic reversing grinding mode when grinding the conical surfaces at both ends of the upper and lower work rolls.

[0009] The above-mentioned roughing roll matching method for controlling the sickle-shaped plate shape of medium and heavy plates, when rolling steel plate billets with a thickness of 250mm and a width of 2100mm into steel plate products with a width of 2200mm or 2500mm, uses finishing rolls with a roll body length of L=3500mm after the mill for grinding treatment of the upper and lower work rolls.

[0010] The roughing roll matching method described above for controlling the sickle-shaped plate of medium and heavy plates has a taper of 1:350 to 1:400 at both ends of the upper and lower work rolls.

[0011] In the roughing roll matching method for controlling the sickle-shaped plate of medium and heavy plates described above, the length dimension L1 of the conical surfaces at both ends is controlled to be 700-800mm during the grinding process of the upper and lower work rolls.

[0012] In the above-mentioned roughing roll matching method for controlling the sickle-shaped plate of medium and heavy plates, the difference in the diameter of the upper and lower work rolls after grinding is no more than 40mm.

[0013] This invention provides a method for controlling the sickle-shaped profile of medium-thick plates in roughing rolling. In the transverse widening process of the roughing stage of steel billets, the finishing rolls from the finishing stage are selected, ground, and used as work rolls for transverse widening in the roughing stage. This not only achieves the reuse of the finishing rolls after they have come off the mill, reducing production costs, but also eliminates slippage during the steel billet biting process due to the roughened surface of the finishing rolls. This invention grinds both ends of the upper and lower work rolls in the transverse widening process of the roughing stage into conical surfaces with a set taper, forming a central diameter... The slightly larger micro-shuttle roll with slightly smaller diameters at both ends allows for greater transverse extension of the steel plate billet during the transverse widening process. This is because the gap between the upper and lower work rolls in the middle is smaller than the gap at both ends. This creates a transverse width redundancy Δ in the middle section. When the steel plate adjusts its direction to enter the subsequent longitudinal rolling process, this transverse width redundancy Δ reduces the width difference between the head, tail, and waist of the steel plate after the longitudinal rolling process. This, to a certain extent, solves the problem of sickle-shaped plate shape in rolled steel plate products and improves the pass rate of rolled steel plate products. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a steel plate sickle-shaped bend. Figure 2 This is a schematic diagram of the roll structure for the transverse widening process in the rough rolling stage of steel slab billet; Figure 3 This is a schematic diagram of the working state of the cross rolling rolls during the roughing stage; Figure 4 This is a schematic diagram of the sequential horizontal and longitudinal rolling process of steel plate billet during the rough rolling stage.

[0015] Explanation of each label in the diagram: 1 represents steel plate products, 1-1 represents steel plate billets, and 1-2 represents intermediate products after the steel plate has been horizontally widened. 2 is the working roller, 2-1 is the upper working roller, and 2-2 is the lower working roller; W represents the sickle-shaped curved line, and Y represents the conical surface. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0017] Referring to Figure 1, the sickle-shaped plate of medium and heavy plate refers to the lateral bending of the steel plate on the horizontal plane, which makes the steel plate resemble a sickle. The symbol W in the figure shows the sickle-shaped arc of steel plate 1. The main reason for the sickle-shaped plate of steel plate product 1 is that uneven extension occurs in the width direction during the rolling process of the steel plate. The rolling process of steel plate product 1 includes roughing and finishing stages. The roughing stage is divided into three steps: forming longitudinal rolling → transverse widening → elongation longitudinal rolling. The intermediate billet obtained after roughing is sent to the finishing stage, where the intermediate billet is further rolled to reduce its thickness. This stage requires strict control over the plate shape, steel plate thickness tolerance, and steel plate surface quality. Therefore, stringent requirements are placed on the surface finish, roll profile accuracy, and roll surface wear resistance of the finishing rolls to ensure the dimensional accuracy and surface quality of the steel plate product. After the finishing rolls have been continuously rolling a certain tonnage of steel plate, the roll surface will gradually wear and scratch, and the roll profile will also deviate. When the roll surface condition and roll profile accuracy can no longer meet the process conditions of the finishing rolling process, the rolls will be removed from the finishing mill stand.

[0018] See Figure 2 , Figure 3 This invention provides a roughing roll arrangement method for controlling the sickle-shaped plate shape of medium-thick plates. In the lateral widening process of the roughing stage, the work roll 2 used to achieve lateral widening consists of an upper work roll 2-1 and a lower work roll 2-2. The special feature is that the upper work roll 2-1 and the lower work roll 2-2 are selected from the finishing rolls after the finishing stage and are ground to form conical surfaces Y with a set taper at both ends. After grinding, the roll shape of the upper work roll 2-1 and the lower work roll 2-2 is consistent.

[0019] See Figure 3 The roughing roll matching method for controlling the sickle-shaped bending of medium-thick plates described in this invention employs a CNC grinding machine to perform the grinding operation on the upper work roll 2-1 and lower work roll 2-2. Based on the different sizes and specifications of the steel plate products 1, the finishing rolls of appropriate length and diameter after exiting the mill are selected as the grinding workpieces. The specific implementation of this invention is as follows: When rolling a steel plate billet 1-1 with a thickness of 250mm and a width of 2100mm into a steel plate product 1 with a width of 2200mm or 2500mm, the upper work roll 2-1 and lower work roll 2-2 of the roughing stage transverse widening process are selected as finishing rolls with a roll body length of L=3500mm after the mill for grinding. They are hoisted onto the worktable of the CNC grinding machine, the position of the bearing of the CNC grinding machine is adjusted to ensure that the roll body of the workpiece is in a horizontal state, and the positioning and clamping of the workpiece is completed.

[0020] When grinding the upper work roll 2-1 and the lower work roll 2-2, the Taper curve trajectory set by the CNC grinding machine control system is first used to grind the conical surface Y at one end of the workpiece. The constant current automatic reversing grinding mode is used, and the length L1 of the conical surface Y is controlled to be 700-800mm, and the taper of the conical surface Y is 1:350-1:400. After the conical surface Y with a taper is machined at one end of the roll, the Sine curve trajectory set by the CNC grinding machine control system is used to make the grinding wheel perform a no-load motion. After the grinding wheel has completed the no-load motion of the middle section of the roll body (length 1900-2100mm), the Taper curve trajectory set by the CNC grinding machine control system is used again to grind the conical surface Y at the other end of the workpiece, and the length L1 of the conical surface is controlled to be 700-800mm, and the taper of the conical surface Y is 1:350-1:400.

[0021] See Figure 4 In a specific embodiment of the present invention, after the steel plate billet 1-1 has completed the transverse widening rolling stage, the width redundancy Δ of the intermediate product 1-2 after the transverse widening of the steel plate can be increased from 30mm to 50mm. In the subsequent elongation rolling process, the width redundancy Δ can make up for the width difference between the head, tail and waist of the steel plate, thereby eliminating the camber phenomenon of the steel plate to a certain extent and making the steel plate product 1 meet the shape tolerance requirements.

[0022] In the grinding process of the work roll 2, the grinding wheels of the grinding machine at both ends adopt the Taper cutting trajectory, and the middle section adopts the Sine curve as the idle motion trajectory of the middle roll body area. Because the displacement, velocity and acceleration of the Sine curve are continuous without abrupt changes, it can avoid mechanical impact and residual vibration generated during motion reversal. When switching to Taper curve grinding, the machine tool has no residual vibration, avoiding the generation of vibration mark defects on the conical transition surface at the end of the workpiece. This not only ensures the grinding accuracy of the conical surface Y at both ends of the workpiece, but also reduces the impact load on the transmission components such as the grinding wheel head, lead screw guide, etc. of the CNC grinding machine, and extends the service life of the machine tool components.

[0023] In a specific embodiment of the present invention, before grinding the work roll 2, the diameter of the selected finishing roll after it exits the finishing rolling stage is measured at different positions on the roll body. There are no fewer than five measurement points, which are located at 150, 700, 1750, 2800, and 3350 mm away from the reference point on the operating side of the rolling production line equipment, in order to determine the initial state of the workpiece being ground, determine the grinding amount of the workpiece, and control the parameters of the CNC grinding machine. After the work roll 2 is ground, the diameter at the above measurement points is measured again to ensure that the dimensions of the workpiece after processing meet the relevant requirements.

Claims

1. A method for adjusting the rolls in a roughing mill to control the sickle-shaped profile of medium-thick plates, characterized in that: In the rolling process of medium and heavy steel plates, the upper working roll (2-1) and lower working roll (2-2) of the transverse widening process in the roughing stage are selected from the finishing rolls after the finishing stage and ground to form conical surfaces with a set taper at both ends. After grinding, the roll shape of the upper working roll (2-1) and the lower working roll (2-2) is consistent.

2. The roughing roll allocation method for controlling the sickle-shaped profile of medium-thick plates according to claim 1, characterized in that: For the grinding of the upper working roll (2-1) and the lower working roll (2-2), a CNC grinding machine is used to perform the grinding operation. According to the steel plate products (1) of different sizes and specifications, the finishing rolls after the machine with the corresponding length and diameter are selected as the grinding workpieces. They are hoisted onto the worktable of the CNC grinding machine, the position of the bearing of the CNC grinding machine is adjusted to ensure that the roller body of the workpiece is in a horizontal state, and the positioning and clamping of the workpiece is completed.

3. The roughing roll allocation method for controlling the sickle-shaped profile of medium-thick plates according to claim 2, characterized in that: When grinding the upper work roll (2-1) and the lower work roll (2-2), the Taper curve trajectory set by the CNC grinding machine control system is first called to grind one end of the workpiece. After machining a tapered conical surface at one end of the roll, the Sine curve trajectory set by the CNC grinding machine control system is called to make the grinding wheel move in idle motion. After the grinding wheel has moved in idle motion through the middle section of the roll body, the Taper curve trajectory set by the CNC grinding machine control system is called again to grind the tapered conical surface at the other end of the workpiece.

4. The roughing roll allocation method for controlling the sickle-shaped profile of medium-thick plates according to claim 3, characterized in that: When grinding the conical surfaces at both ends of the upper work roll (2-1) and the lower work roll (2-2), a constant current automatic reversing grinding mode is adopted.

5. The roughing roll allocation method for controlling the sickle-shaped profile of medium-thick plates according to claim 4, characterized in that: When rolling a steel plate billet (1-1) with a thickness of 250mm and a width of 2100mm into a steel plate product (1) with a width of 2200mm or 2500mm, the upper working roll (2-1) and the lower working roll (2-2) are selected from the finishing rolls after the mill with a roll body length of L=3500mm for grinding.

6. The roughing roll allocation method for controlling the sickle-shaped profile of medium-thick plates according to claim 5, characterized in that: The taper of the conical surfaces at both ends of the upper and lower working rollers is 1:350 to 1:

400.

7. The roughing roll allocation method for controlling the sickle-shaped profile of medium-thick plates according to claim 6, characterized in that: During the grinding process of the upper working roll (2-1) and the lower working roll (2-2), the length dimension L1 of the conical surface at both ends is controlled to be 700-800mm.

8. The roughing roll allocation method for controlling the sickle-shaped profile of medium-thick plates according to any one of claims 4 to 7, characterized in that: After grinding, the difference in diameter between the upper working roll (2-1) and the lower working roll (2-2) shall not exceed 40 mm.

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