A production method of pinch roll for high speed wire rod with super design limit large size

Abstract

The application relates to a high-speed wire rod over-design limit large-size pinch roll production method and belongs to the technical field of high-speed wire rod rolling methods.The technical scheme of the application is that a pinch roll is additionally arranged at the position of a No.13 rolling mill on a production line;the existing rolling mill is used as the newly-added pinch roll, a pinch roll pass is designed on the roller according to the material type, and the pinch roll gap is adjusted through the rolling mill adjusting mechanism;in the production process of the limit large-size product, the speed and time sequence of the newly-added pinch roll and the original pinch roll before the finishing mill are electrically interlocked controlled to form double pinch rolls before the reducing sizing mill.The application has the beneficial effects that the tension and movement stability of the rolled piece in the idle interval of the intermediate rolling mill to the reducing sizing mill are ensured, the problems of starting and knotting are successfully solved, production accidents are eliminated, equipment damage and the loss of manpower and material resources caused by the accidents are avoided, the bottleneck problem of producing large-size products is solved, and continuous and stable production order is formed.

Description

TECHNICAL FIELD

[0001] The application relates to a high-speed wire rod over-limit large-specification pinch roll production method and belongs to the technical field of high-speed wire rod rolling methods. BACKGROUND

[0002] With the continuous refinement of market division, the user product continuously improves the requirement for near-end type raw materials, leading to the continuous breakthrough of the limit specification of the processing production line. In modern high-speed wire rod production, due to the long coiling length and the self-advantage of no joint, the demand of the large-specification coiling in the processing industry is increasingly large, and the limit large specification of the product is also widened from the original to Recently, the over-limit specification is gradually developed. In the development and production of these limit large specifications, due to the characteristics of the wire rod production line: the distance between the finished product front rolling mill and the finished product reducing mill is 154 meters (see Figure 1 high-speed wire rod production process layout), the empty space is too long, and the head power of the rolling piece is insufficient in the conveying process, and the bending force of the tail end in the empty space is serious, which leads to the frequent occurrence of production accidents such as knotting and looping. In the original design, there is a pinch roll device in front of the finishing mill, but due to the too long distance, it cannot make up for the power transmission problem of the empty space after the intermediate rolling, and it cannot realize normal continuous production. SUMMARY

[0003] The application aims to provide a high-speed wire rod over-limit large-specification pinch roll production method. A new pinch roll device is added after the intermediate rolling 2# flying shear, a double pinch roll device is formed with the original pinch roll in front of the finishing mill, and corresponding interlocking control is added to ensure the tension and movement stability of the rolling piece in the empty space interval from the intermediate rolling to the reducing mill, successfully solving the problems of looping and knotting, eliminating production accidents, eliminating the damage of equipment and the loss of manpower and material resources, solving the bottleneck problem of large-specification production, forming a continuous and stable production order, successfully developing a wire rod over-limit specification, widening the group distance of the wire rod product, breaking through the production specification limit of the same type of equipment production line, making a contribution to the development of the entire high-speed wire rod industry, and effectively solving the above problems existing in the background technology.

[0004] The technical scheme of the application is as follows: a high-speed wire rod over-limit large-specification pinch roll production method, comprising the following steps:

[0005] (1) over-limit large-specification production problem analysis and position selection of the added pinch roll; the NO. 13 mill position is selected on the production line to add a pinch roll;

[0006] (2) the added pinch roll adopts the existing mill as the added pinch roll, the pinch roll pass is designed on the mill roll according to the material type, and the pinch roll gap is adjusted through the mill adjusting mechanism;

[0007] (3) The speed and interlocking electrical control of the double pinch roll, in the process of producing the extreme large size product, the speed and time sequence of the new pinch roll and the original pinch roll before the finishing mill are electrically interlocked to form the double pinch roll before the reducing sizing.

[0008] In the step (1), the bending of the compression bar is analyzed by using the Euler formula in material mechanics, the rolled piece at the 2# flying shear is regarded as a compression bar, if the rolled piece is bent by a large thrust, it will be pushed out from the guide groove after shearing, causing the steel piling accident, thus the position of the new pinch roll is determined after the 2# flying shear and the position of the NO.13 mill.

[0009] In the step (2), according to the NO.12 mill material Φ32.4mm circle, the open type groove top circle arc is adopted for the pinch roll groove, the radius R is 16.5mm, the side wall of the groove is 35°, the groove round radius r is 2mm transition; the pinch roll gap is designed as an adjustable structure, the adjustment mode of the mill roll gap is used, considering the bounce of the mill and the deviation of the material adjustment, when the roll gap is set, the adjustment value is 0.5mm smaller than the rolled piece.

[0010] In the step (3), the control time sequence and speed of the double pinch roll are based on the NO.12 mill, 10 seconds after the head of the rolled piece is out of the NO.12 mill, the new pinch roll executes the closing pinch action; 17 seconds after the head of the rolled piece is out of the NO.12 mill, the pinch roll before the finishing mill executes the closing pinch action; after the head of the rolled piece is bitten into the reducing sizing mill set, the pinch roll before the finishing mill executes the opening action, the new pinch roll ensures the pinch state; the setting speed of the new pinch roll is 5-7% higher than the NO.12 mill, the speed change of the pinch roll before the finishing mill is 8-13% higher than the new pinch roll, so that the rolled piece forms a micro tension between the two pinch rolls, avoiding the steel piling accident; the continuous rolling speed matching relationship between the two pinch rolls is adjusted by the change of the lead coefficient.

[0011] The beneficial effects of the present application are: by increasing a new pinch roll device after the 2# flying shear in the intermediate rolling, forming a double pinch roll device with the original pinch roll before the finishing mill, and increasing the corresponding interlocking control, the tension and motion stability of the rolled piece in the empty interval from the intermediate rolling to the reducing sizing mill are ensured, the problems of the loop and the knot are successfully solved, the production accidents are eliminated, the equipment damage and the loss of manpower and material resources caused thereby are prevented, the bottleneck problem of producing the large size is solved, the continuous and stable production order is formed; on this basis, the ultra-limit size wire rod is successfully developed, the pitch of the wire rod product is widened, the production specification limit of the same type equipment production line is broken through, and contribution is made for the development of the entire high-speed wire rod industry. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1It is the wire rod double pinch roll process layout of the application;

[0013] Figure 2 It is the pass structure diagram of the newly added pinch roll of the application;

[0014] Figure 3 It is the electric control program logic diagram of the double pinch roll of the application;

[0015] In the figure: heating furnace 1, descaling machine 2, rough rolling front guide roller 3, rough rolling mill group 4, 1# flying shear 5, medium rolling mill group 6, 2# flying shear 7, pre-finishing rolling mill group 8, side loop 9, Morgan pre-finishing rolling mill group 10, 1# water cooling section 11, finishing rolling front pinch roll 12, switch 13, broken shear 14, finishing rolling mill group 15, 2# water cooling section 16, reducing sizing mill group 17, 3# water cooling section 18, Stelmor cooling line 19, PF line 20, uncoiling station 21, packing machine 22, double core rod 23, coiling drum 24, wire rod machine 25, finishing rolling front pinch roll 26, diameter measuring instrument 27, newly added pinch roll 28, groove top arc 281, pass fillet 282, pass side wall 283, roll gap 284. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the application embodiment clearer, the technical scheme of the application embodiment will be clearly and completely described below in combination with the drawings in the application embodiment. Obviously, the described application embodiment is only a part of the application embodiment, not all the application embodiment. Based on the application embodiment, all other application embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0017] A high-speed wire rod pinch roll production method for ultra-design limit large specifications, comprising the following steps:

[0018] (1) ultra-limit large specification production problem analysis and position selection of newly added pinch roll, selecting NO. 13 mill position on the production line to add a pinch roll;

[0019] (2) newly added pinch roll, using the existing mill as a newly added pinch roll, designing the pinch roll pass on the roll according to the material type, and adjusting the pinch roll gap through the mill adjustment mechanism;

[0020] (3) speed and interlocking electrical control of double pinch roll, during the production process of the limit large specification product, the speed and timing of the newly added pinch roll and the original finishing rolling front pinch roll of the production line are electrically interlocked controlled to form a double pinch roll before the reducing sizing.

[0021] In the step (1), the bending of the compression bar is analyzed by using the Euler formula in material mechanics, the rolled piece at the 2# flying shear is regarded as a compression bar, if the rolled piece is bent by a larger thrust force, it will be pushed out from the guide groove after shearing, and the steel pile-up accident occurs, so the position of the new pinch roll is determined after the 2# flying shear and the NO.13 stand.

[0022] In the step (2), according to the NO.12 stand material type Φ32.4mm circle, the pinch roll pass adopts an open type groove top circle arc with a radius R of 16.5mm, the pass side wall adopts 35°, and the pass fillet radius adopts r of 2mm transition; the pinch roll gap is designed as an adjustable structure, the adjustment mode of the rolling mill gap is used, considering the springback of the rolling mill and the deviation of the material, when the roll gap is set, the adjustment value is 0.5mm smaller than the rolled piece.

[0023] In the step (3), the control timing and speed of the double pinch rolls are based on the NO.12 stand rolling mill, 10 seconds after the head of the rolled piece is out of the NO.12 stand rolling mill, the new pinch roll executes the closing pinch action; 17 seconds after the head of the rolled piece is out of the NO.12 stand rolling mill, the pre-finishing pinch roll executes the closing pinch action; after the head of the rolled piece is bitten into the reducing stand, the pre-finishing pinch roll executes the starting action, and the new pinch roll ensures the pinch state; the setting speed of the new pinch roll is 5-7% higher than the NO.12 stand rolling mill, the speed change of the pre-finishing pinch roll is 8-13% higher than the new pinch roll, so that the rolled piece forms a micro tension between the two pinch rolls, and the steel pile-up accident is avoided; the continuous rolling speed matching relationship between the double pinch rolls is adjusted by the change of the lead coefficient.

[0024] As Figure 1 Because the wire rod production exceeds the limit specification (the diameter is greater than 26mm), the size is large, the empty stand times are more, the rolled piece is all empty from the 12th stand (the last stand of the intermediate rolling) to the 27th stand (the first stand of the reducing), the conveying distance is long (154m), the running resistance is large, and the steel pile-up accident is prone to occur. In order to ensure the smooth conveying of the rolled piece, the 13th stand rolling mill (the first stand of the pre-finishing rolling) is used as the pinch roll for intermediate pinch, the normal biting of the rolling mill is ensured by using the general roll and designing and processing the pass of the roll, and the electric control program of the 13th stand rolling mill as the pinch roll is compiled, the original electric control of the pre-finishing pinch roll is combined, and the double pinch roll control process is formed.

[0025] In order to solve the problems of large specification, large rolling mill spacing, easy steel pile-up and surface scratch, the 13th stand rolling mill is selected as the pinch roll, the pinch roll pass is designed according to the material type, the electric control program of the rolling mill as the pinch roll is compiled, the process design of the double pinch roll before the reducing is formed, and the smooth rolling of the rolled piece is ensured.

[0026] The technical scheme of the present application is:

[0027] A pinch roll was added to the No. 13 stand of the production line, using the existing mill as the new pinch roll. The pinch roll pass was designed according to the material profile, and the pinch roll gap was adjusted through the mill's adjustment mechanism. During the production of ultra-large-sized products, a corresponding control sequence was established, and an electrical control program for the pinch roll was written. This allows the newly added pinch roll 28 to form a double-pinch roll process design before the sizing and reduction, together with the existing pre-finishing pinch roll 12. This solves the problem of conveying ultra-large-sized products beyond the design limit in actual production, ensures smooth passage of rolled pieces, reduces steel stacking accidents during sleeve lifting, and improves continuous and stable production.

[0028] The design steps of this invention are as follows:

[0029] 1. Analysis of problems in ultra-large-scale production and selection of the location for adding pinch rollers;

[0030] 2. The design of the new pinch roller system includes: the design of the new pinch roller die shape and the setting of the pinch roller gap;

[0031] 3. Speed ​​and interlocking electrical control of the double pinch rollers.

[0032] This design is carried out in steps. First, the causes of the formation of large-size top steel are analyzed, and then the location and scheme of the new pinch roll are determined. Then, the new pinch roll die shape is designed and the roll gap is controlled. Next, the interlocking electrical control program of the new and existing pinch rolls is edited. Finally, the production process of double pinch rolls for high-speed wire rod with ultra-large specifications is realized.

[0033] (1) Formation of large-diameter top steel: Theoretical calculation and cause analysis:

[0034] The bending of the compression bar was analyzed using Euler's formula in mechanics of materials. The rolled piece located at shear #2 was considered as a compression bar. If the rolled piece is subjected to a large thrust and bends, it will be ejected from the guide groove after shearing, causing a steel pile-up accident. The above phenomenon will be analyzed using Euler's formula below.

[0035] Critical force for column stability Euler's formula

[0036] Where: E—Young's modulus of the material;

[0037] i — Moment of inertia (cross-sectional parameter);

[0038] μ — constraint coefficient;

[0039] L – Rod length;

[0040] Analysis of Euler's formula yields:

[0041] ① The larger the Young's modulus E and moment of inertia i of the material, the greater the critical force and the more stable the column.

[0042] The smaller the constraint coefficient μ, the shorter the length, and the greater the critical force, the more stable the compression rod.

[0043] The rolled piece of Φ32.4mm round bar is rolled from 12 rolling mills. The bending limit force of φ32.4 steel bar in the 2# flying shear guide is calculated by Euler formula as follows:

[0044] Table 1 Rolled piece bending limit force calculation table

[0045]

[0046] If the steel bar receives a bending limit force greater than that of the rolled piece, it will bend at that position, the closed part will receive external constraints, and the open part will rush out of the guide and form a knot to cause a steel pile accident.

[0047] (2) Analysis of the stress of the rolled piece after the 2# flying shear and determination of the position of the newly added pinch roll

[0048] The 2# flying shear guide is located at the 2# flying shear after the 12 rolling mills. The rolled piece is pushed by the rolling mill and sent into the reducing mill along the guide. In this process, the rolled piece is pushed by the rolling mill on the back and is subjected to various resistances in the running channel. (Of course, the rolled piece lies in the channel, and the support force of the guide wall causes the constraint coefficient μ to decrease, making the rolled piece less likely to bend)

[0049] As can be seen from the above, the rolled piece near the 12 rolling mills has the maximum pushing force (because the combined force of friction resistance is the largest) from the 12 rolling mills to the reducing mill. Therefore, the pressure (pushing force) of the rolled piece at this position is most likely to exceed the critical force F cr , that is, the rolled piece is most likely to bend and pile up at this position.

[0050] The combined force ΣF of the rolled piece at the 2# flying shear guide is:

[0051] ΣF = Fm + F j + Fa + Fc + Fy

[0052] Fm——the normal friction resistance of the horizontal guide to the rolled piece;

[0053] F j ——the resistance of cooling water, compressed air and other media to the rolled piece;

[0054] Fa = ma——the acceleration force due to the change of speed of the rolled piece;

[0055] Fc——the axial force of the guide inlet chamfer to the end of the rolled piece;

[0056] Fy - the hard resistance caused by the collision due to the unexpected installation, processing and other conditions of the components in the channel.

[0057] It is calculated that the gap position of the 2# flying shear after 12 rolling mills is the position where the maximum comprehensive resistance is received, that is, the point of frequent steel stacking accidents. The most suitable equipment for pinch roll is found under the conditions of mechanical, power and electrical control. The 13th rolling mill is closest to this position and fully meets the requirements of various conditions. Therefore, the 13th rolling mill is determined as the newly added pinch roll.

[0058] 2. The design of the newly added pinch roll system, including the pass design and roll gap setting of the newly added pinch roll.

[0059] The original 13th roller is used as the newly added pinch roll, and the guide roller can save the cost to the maximum extent. The pass design of the newly added pinch roll is as follows. According to the material shape of the 12th blank, it is a circular shape with a diameter of 32.4. In order to avoid scratching and indentation of the pinch roll, the pinch pass is designed as an open type round bottom pass with a radius R of 16.5, the pass side wall is 35°, the pass fillet radius is r, which is 2 transition, to avoid the deformation and scratching of the rolled piece in the working process, and to avoid damage to the surface.

[0060] The roll gap is designed to be adjustable, and the adjustment mode of the roll gap of the rolling mill is used. Considering the springback of the rolling mill and the deviation of the adjustment, when the roll gap is adjusted, the adjustment value is 0.5mm smaller than the rolled piece.

[0061] 3. Speed and interlocking electrical control of double pinch rolls

[0062] Because the speed of the rolled piece is constantly changing in the actual production process, the speed of the newly added pinch roll must match the rolled piece, so the electrical control is designed to form interlocking control with the speed of the previous 12 rolls. Because there is a design of the front pinch roll in the conventional design of high-speed wire, the electrical control problem of the double pinch roll is involved in the present application.

[0063] In the control system of high speed wire rod, the control of the pinch roll before the original finishing rolling includes the opening and closing time of the pinch roll, the lifting speed, the cascade and timing problem with other rolling mills and detecting elements; now the newly added pinch roll after the No. 2 flying shear is added, the cascade and timing problem of the newly added pinch roll with other equipment and detecting elements is added, and the correlation and control problem of the original pinch roll and the newly added pinch roll is also brought. In the present application, the control timing and speed of the double pinch roll are set based on the No. 12 mill, the newly added pinch roll 28 performs the closing pinch action 10 seconds after the head of the rolled piece comes out of the No. 12 mill. The finishing pinch roll 12 performs the closing pinch action 17 seconds after the head of the rolled piece comes out of the No. 12 mill; the finishing pinch roll 12 performs the opening action after the head of the rolled piece bites into the reducing mill train 17, and the newly added pinch roll 28 ensures the pinch state; the set speed of the newly added pinch roll 28 is 5-7% higher than the leading coefficient of the No. 12 mill, and the speed change of the finishing pinch roll 12 is 8-13% higher than the leading coefficient of the newly added pinch roll, so that the rolled piece can form a micro tension between the two pinch rolls, and the steel stacking accident can be avoided; the continuous rolling speed matching relationship between the double pinch rolls can be adjusted by changing the leading coefficient.

[0064] The above examples are only used to illustrate but not to limit the technical solutions of the present application, although the present application is described in detail with reference to the above examples, those skilled in the art should understand that the present application can still be modified or equivalently replaced without departing from the spirit and scope of the present application, any modification or partial replacement should be covered in the scope of the claims of the present application.

Claims

1. A pinch roll production method for high speed wire rod over design limit large gauge, characterized in that Comprise the following steps: (1) Analysis of the problem of production of large specifications beyond the design limit and selection of the position of the newly added pinch roll, and selection of the position of the newly added pinch roll at No. 13 mill position on the production line; (2) Newly added pinch roll, using the existing mill as the newly added pinch roll, designing the pinch roll pass on the roll according to the material type, and adjusting the roll gap of the pinch roll through the mill adjustment mechanism; (3) Speed and interlocking electrical control of the double pinch roll, during the production of the product with large specifications beyond the design limit, the speed and timing of the newly added pinch roll and the original pinch roll before finishing are electrically interlocked and controlled, forming double pinch rolls before reducing the diameter; In step (3), the control timing and speed of the double pinch roll are based on No. 12 mill, 10 seconds after the head of the rolled piece exits No. 12 mill, the newly added pinch roll performs the closing pinch action; 17 seconds after the head of the rolled piece exits No. 12 mill, the pinch roll before finishing performs the closing pinch action; after the head of the rolled piece bites into the reducing diameter mill train, the pinch roll before finishing performs the opening action, and the newly added pinch roll ensures the pinch state; The set speed of the newly added pinch roll is 5-7% higher than the lead coefficient of No. 12 mill, and the speed of the pinch roll before finishing is 8-13% higher than the lead coefficient of the newly added pinch roll, so that the rolled piece forms a micro tension between the two pinch rolls, avoiding the steel stacking accident; The continuous rolling speed matching relationship between the double pinch rolls is adjusted by changing the lead coefficient.

2. The pinch roll production method for high speed wire rod over-design large size according to claim 1, characterized in that: In step (2), according to the material type of No. 12 mill, the diameter is Φ32.4mm, the open slot top circle arc is used for the pinch roll pass, the radius R is 16.5mm, the side wall of the pass is 35°, and the pass fillet radius r is 2mm transition; The roll gap of the pinch roll is designed as an adjustable structure, and the adjustment mode of the mill roll gap is used, considering the springback of the mill and the deviation of the material adjustment, when setting the roll gap, the adjustment value is 0.5mm smaller than the rolled piece.

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