Method for controlling the homogeneity of the longitudinal wall thickness of a tube
By dynamically adjusting the roll gap and mandrel extension of the piercing mill during seamless steel pipe production, the problem of large longitudinal differences in the wall thickness of the tube was solved, thereby improving the uniformity of the tube wall thickness and the quality of the finished product.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BAOSHAN IRON & STEEL CO LTD
- Filing Date
- 2022-08-25
- Publication Date
- 2026-05-19
AI Technical Summary
In the existing seamless steel pipe production process, the pre-adjustment of the roller gap and mandrel extension of the piercing mill leads to a large difference in the longitudinal thickness of the tube, resulting in a thicker tube head and a thinner tube tail, which affects the quality of the finished product and is prone to quality defects.
By dynamically adjusting the roll gap and mandrel extension of the piercing mill during the piercing process, and utilizing historical optimized piercing ternary data combination and online wall thickness detection, the roll gap and mandrel positions are corrected in real time to achieve longitudinal uniformity of capillary wall thickness.
This achieves uniformity of tube wall thickness in the longitudinal direction, improves the wall thickness uniformity and quality level of finished seamless steel pipes, and avoids internal folding defects and rolling failures.
Smart Images
Figure CN117655110B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a piercing control technology for seamless steel pipe production, and more particularly to a capillary piercing control method for improving longitudinal wall thickness uniformity. Background Technology
[0002] In the current seamless steel pipe production process, the piercing mill pierces solid billets into hollow tubes, which is the most widely used tube forming method. The two-roll skew rolling piercing mill is a relatively mature piercing mill. This type of piercing mill has a pair of piercing rolls and a mandrel. The final forming of the tube is mainly achieved by adjusting the gap between the piercing rolls and the forward extension of the mandrel.
[0003] In existing processes, the adjustment of the piercing mill roll gap and mandrel extension is performed before piercing and is not carried out during the piercing process. However, in daily production, the average wall thickness of the pierced tube varies significantly along the longitudinal direction, with the thickest wall at the tube head, followed by the tube body, and the thinnest at the tube tail. This wall thickness difference can reach 0.3–2 mm, which adversely affects the wall thickness and quality of downstream units and finished seamless steel pipes. It can easily lead to problems such as excessively thick wall at the tube head and insufficiently thin wall at the tube tail, as well as quality defects such as rolling jamming, dents, and holes in downstream units.
[0004] The following are the relevant patents found in this field:
[0005] Chinese patent (CN109092900A) discloses a process for improving the wall thickness accuracy of medium-thick walled tubes, including steps such as casting steel pipes, piercing machine correction, cold centering machine drilling and inspection, coefficient modification, and centerline adjustment. This invention improves the yield of medium-thick walled tubes with diameters ranging from φ273×6 to 35mm through mandrel modification, standardized centering hole procedures, and optimized tension coefficient of the sizing machine. However, this patent does not mention the dynamic adjustment of the roll gap and mandrel position under load.
[0006] Chinese patent (CN110711779A) discloses a method for controlling the wall thickness of seamless steel pipes, including steps such as billet preparation, ring furnace heating, piercing mill piercing, rolling mill, reheating furnace, sizing and reducing unit, and cooling. It improves wall thickness uniformity by limiting heating temperature, piercing mandrel outer diameter, roll gap, guide distance, reheating furnace temperature, and motor speed. However, this patent does not mention the dynamic adjustment of roll gap and mandrel position under load. Summary of the Invention
[0007] The purpose of this invention is to provide a capillary perforation control method to improve the uniformity of longitudinal wall thickness. This capillary perforation control method can dynamically adjust and control the capillary wall thickness during the perforation process of the perforating machine, so that the wall thickness of the perforated capillary can be uniform in the longitudinal direction.
[0008] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:
[0009] A method for controlling capillary perforation to improve longitudinal wall thickness uniformity includes:
[0010] S1. Before piercing the tube blank, obtain the historical optimized piercing three-dimensional data combination corresponding to the target forming tube according to the variety and specifications of the tube.
[0011] The historical optimized punched three-data combination is the data structure of the punched three-data combination;
[0012] The perforation three-dimensional data combination is composed of n three-dimensional data nodes arranged and combined. The three-dimensional data nodes include perforation three-dimensional data, which are length point, roll gap adjustment amount and mandrel forward extension adjustment amount, and n is a natural number.
[0013] S2, construct the actual application of the punching three-data combination based on the historical optimized punching three-data combination;
[0014] S3, the tube blank enters the piercing mill for piercing. During the piercing process, the roller gap and mandrel extension of the piercing mill are dynamically adjusted according to the actual application piercing three data combination.
[0015] S4, during the perforation process, the actual wall thickness data of the perforated capillary is obtained;
[0016] S5. Based on the actual wall thickness data of the perforated capillary tube, optimize and correct the historical optimized perforation three-data combination corresponding to the variety and specifications of the capillary tube.
[0017] Furthermore, the top-ranked ternary data nodes in the constructed practical application ternary data combination are the top-ranked ternary data nodes in the historically optimized ternary data combination, while the bottom-ranked ternary data nodes in the practical application ternary data combination are the bottom-ranked ternary data nodes in the historically optimized ternary data combination.
[0018] Furthermore, the actual application of the punched data set is constructed according to a preset data set construction strategy, which includes:
[0019] S21, estimate the total length of the target forming tube after perforation in advance;
[0020] S22, the estimated total length of the target formed capillary after perforation is divided by the adjustment cycle length, and the resulting value is the number of nodes constructed.
[0021] S23, compare the number of nodes constructed with the number of nodes in the historical optimized perforation three-data combination, and take the absolute value of the difference in the number of nodes as the number of node changes;
[0022] S24. If the number of nodes constructed is equal to the number of nodes in the historical optimized perforated ternary data combination, then the historical optimized perforated ternary data combination shall be used as the actual application perforated ternary data combination.
[0023] S25. If the number of nodes constructed is greater than the number of nodes in the historical optimized perforated ternary data combination, then a new perforated ternary data combination is constructed based on the historical optimized perforated ternary data combination. According to the number of node changes, ternary data nodes are added at the midpoint of the node sorting in the new perforated ternary data combination. The added ternary data nodes are copies of the ternary data nodes at the midpoint of the node sorting in the historical optimized perforated ternary data combination. Then, the length positions of all ternary data nodes in the new perforated ternary data combination are adjusted for adaptation. Finally, the newly constructed perforated ternary data combination is used as the perforated ternary data combination for actual application.
[0024] S26. If the number of nodes constructed is less than the number of nodes in the historical optimized perforated ternary data combination, then a new perforated ternary data combination is constructed based on the historical optimized perforated ternary data combination. According to the number of nodes changed, the ternary data nodes in the middle of the sorting in the new perforated ternary data combination are deleted. Then, the length position of all ternary data nodes in the new perforated ternary data combination is adjusted for adaptive sorting. Finally, the newly constructed perforated ternary data combination is used as the perforated ternary data combination for actual application.
[0025] Furthermore, S2 also includes: after completing the construction of the actual application perforation three-dimensional data combination, replacing the historical optimized perforation three-dimensional data combination corresponding to the capillary of the variety specification with the actual application perforation three-dimensional data combination as the new historical optimized perforation three-dimensional data combination.
[0026] Further, S4 includes:
[0027] S41, During the piercing process, when the pierced tube exits the piercing machine outlet, the circumferential wall thickness data of the tube after each dynamic adjustment is actually detected, and the average wall thickness after each dynamic adjustment is calculated.
[0028] S42. After the perforation is completed, all the obtained average wall thickness values after one dynamic adjustment are arranged and combined into an ordered data set according to the order of detection. This data set is the actual average wall thickness data set of the capillary tube.
[0029] Furthermore, S5 also includes: the optimization correction of the historical optimized perforation ternary data combination is performed according to a preset ternary data correction strategy, the ternary data correction strategy including:
[0030] For each ternary data node in the historical optimized piercing ternary data combination, determine the roll gap correction amount and the mandrel extension amount correction amount. Then, use the roll gap correction amount to correct the roll gap adjustment amount in the ternary data node, and use the mandrel extension amount correction amount to correct the mandrel extension amount adjustment amount in the ternary data node.
[0031] The roll gap correction amount is based on the formula The formula is used to calculate and determine the value of the roll gap correction, where ΔE is the inlet cone angle of the piercing roll of the piercing mill, α2 is the deviation between the actual wall thickness and the target thickness, and α is the value of the deviation between the actual wall thickness and the target thickness. lgt2 The angle of the rolling cone at the top;
[0032] The correction amount for the mandrel extension is calculated and determined according to the formula ΔR=0.5×ΔE / tan(α2), where ΔR is the correction amount for the mandrel extension, α2 is the angle of the cone surface at the entrance of the piercing roller of the piercing machine, and ΔE is the correction amount for the roller gap.
[0033] Furthermore, in S41, the circumferential wall thickness data after each dynamic adjustment of the actual detected capillary is implemented by an online wall thickness detection device;
[0034] The online wall thickness detection device is a device installed at the outlet of the perforating machine that can measure the capillary wall thickness without contact. The online wall thickness detection device has several non-contact thickness measuring probes, which are evenly arranged around the circumference of the capillary.
[0035] In the capillary piercing control method of the present invention, during the piercing process of the tube blank entering the piercing mill, the adjustment amounts of the roller gap and mandrel extension of the piercing mill are dynamically adjusted according to the actual application piercing three-dimensional data combination. This allows for dynamic adjustment and control of the tube wall thickness during piercing, ensuring that the wall thickness of the pierced tube is uniform in the longitudinal direction. When dynamically adjusting the roller gap and mandrel extension during piercing, the adjustment amounts of both are adjusted according to an adjustment ratio of 2tan(α2):1. This ensures that the positions of the roller gap and mandrel are matched during piercing, thereby avoiding internal folding defects in the pierced tube, guaranteeing the inner surface quality of the tube, and ensuring the stability of the piercing process. The production database pre-stores historical optimized piercing ternary data combinations for various types and specifications of tubes. Before piercing, the historical optimized piercing ternary data combinations are extracted and the actual application piercing ternary data combinations are constructed. Then, the roll gap and mandrel extension are dynamically adjusted based on the actual application piercing ternary data combinations. This approach helps to adjust the roll gap and mandrel extension to the appropriate adjustment amount for the tube type and specifications before piercing, avoiding large wall thickness deviations when changing specifications, thus enabling better control of the tube wall thickness.
[0036] Compared with the prior art, the capillary piercing control method of the present invention has the following advantages: the wall thickness of the capillary is dynamically adjusted and controlled during the piercing process of the billet entering the piercing machine, so that the wall thickness of the capillary after piercing can be uniform in the longitudinal direction, which is beneficial to the subsequent seamless steel pipe production process, improves the wall thickness uniformity of the final seamless steel pipe, and thus improves the quality level of the finished seamless steel pipe. Attached Figure Description
[0037] Figure 1 This is a flowchart of the capillary perforation control method for improving longitudinal wall thickness uniformity according to the present invention. Detailed Implementation
[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:
[0039] This embodiment provides a capillary perforation control method to improve the uniformity of longitudinal wall thickness. This capillary perforation control method realizes dynamic adjustment and control of capillary wall thickness during the perforation process of the perforating machine, so that the wall thickness of the perforated capillary can be uniform in the longitudinal direction.
[0040] Before explaining the capillary perforation control method of this embodiment in detail, some concepts involved in this embodiment are explained as follows:
[0041] The piercing mill involved in this embodiment is a two-roll skew rolling piercing mill, which is a prior art piercing mill model. It has a pair of piercing rolls and a mandrel. The adjustment of the piercing roll gap and the adjustment of the mandrel extension are both driven by a hydraulic drive mechanism.
[0042] It should be noted that the roll gap mentioned in this article refers to the roll gap of the piercing roll of the piercing machine.
[0043] It should be noted that the piercing mentioned in this article refers to the piercing operation of a piercing machine on a solid tube blank.
[0044] To implement the capillary perforation control method of this embodiment, a novel data structure is created, referred to as the "perforation ternary data combination." This perforation ternary data combination consists of n data nodes arranged in a specific order. Each data node in the perforation ternary data combination is called a "ternary data node," and each ternary data node contains three data points, which are called "perforation ternary data points." Here, n is a natural number. The perforation ternary data combination can be stored in a computer as a two-dimensional array.
[0045] The three data points for piercing are "length position, roll gap adjustment amount, and mandrel extension adjustment amount". The length position refers to the length position on the formed tube after piercing during the piercing process; the roll gap adjustment amount refers to the amount by which the piercing machine adjusts the roll gap; and the mandrel extension adjustment amount refers to the amount by which the piercing machine adjusts the mandrel extension.
[0046] The significance of the three data points of the piercing process is that, during the piercing process, when the length of the pierced tube reaches the length point, the piercing machine is controlled to adjust the roller gap and the mandrel extension according to the roller gap adjustment amount and the mandrel extension amount adjustment amount.
[0047] The significance of the aforementioned piercing ternary data combination lies in its ability to dynamically adjust the roll gap and mandrel extension of the piercing machine during the piercing process. Specifically, this piercing ternary data combination is designed for obtaining a tube through piercing. During the piercing process, when the "length of the pierced tube" reaches the "length point in the first ternary data node of the piercing ternary data combination," the piercing machine is controlled to adjust the roll gap and mandrel extension based on the roll gap adjustment and mandrel extension adjustment amounts in that first ternary data node. When the "length of the pierced tube" reaches the "length point in the second ternary data node of the piercing ternary data combination," the piercing machine is controlled to adjust the roll gap and mandrel extension based on the "length point in the first ternary data node." The roll gap and mandrel extension are adjusted according to the roll gap adjustment and mandrel extension adjustment in the second three-dimensional data node, and so on, until the "length of the pierced tube" reaches the "length point in the last three-dimensional data node in the piercing three-dimensional data combination". Then, the piercing machine is controlled to adjust the roll gap and mandrel extension according to the roll gap adjustment and mandrel extension adjustment in the last three-dimensional data node, thus completing the whole process of "controlling the piercing machine to dynamically adjust the roll gap and mandrel extension according to the piercing three-dimensional data combination".
[0048] It should be noted that the difference in length between any two adjacent ternary data nodes in the piercing ternary data set is a pre-set fixed length value, which is called the "adjustment cycle length". Therefore, the previously mentioned "controlling the dynamic adjustment of the roll gap and mandrel extension of the piercing machine according to the piercing ternary data set" can be understood as follows: during the piercing process, the piercing machine is periodically adjusted once the length of the pierced tube increases by one adjustment cycle length.
[0049] The following example illustrates the process of "controlling the dynamic adjustment of roll gap and mandrel extension of the piercing mill based on the combination of piercing three data elements":
[0050] For example, the perforation three-dimensional data combination contains 1000 three-dimensional data nodes, and the adjustment cycle length is preset to 10mm. The perforation three-dimensional data nodes of the 1st, 2nd, 3rd, ..., 999th and 1000th three-dimensional data nodes in the perforation three-dimensional data combination are (10mm, 153.2mm, 85mm), (20mm, 153.15mm, 84.7mm), (30mm, 153.11mm, 84.5mm), ..., (9990mm, 152.1mm, 82.1mm), and (10000mm, 152.05mm, 82.14mm), respectively. The order of the perforation three-dimensional data is (length point, roll gap adjustment amount, mandrel forward extension adjustment amount). During the piercing process, when the tube length reaches 10mm, the piercing machine is controlled to adjust the roll gap and mandrel extension to 153.2mm and 85mm respectively, based on the first three-dimensional data node. When the tube length reaches 20mm, the piercing machine is controlled to adjust the roll gap and mandrel extension to 153.15mm and 84.7mm respectively, based on the second three-dimensional data node. When the tube length reaches 30mm, the piercing machine is controlled to adjust the roll gap and mandrel extension to 153.11mm and 84mm respectively, based on the third three-dimensional data node. 0.5mm, ..., when the tube length reaches 9990mm, the piercing machine is controlled to adjust the roll gap and mandrel extension to 152.1mm and 82.1mm respectively according to the 999th three-dimensional data node. When the tube length reaches 10000mm, the piercing machine is controlled to adjust the roll gap and mandrel extension to 152.05mm and 82.14mm respectively according to the 1000th three-dimensional data node, thus completing the entire process of "controlling the piercing machine to dynamically adjust the roll gap and mandrel extension according to the combination of piercing three-dimensional data".
[0051] It should be noted that the "historical optimized punched three-data combination", "actual application punched three-data combination", etc. mentioned later are all data structures of punched three-data combination.
[0052] The above is an explanation of some concepts involved in this embodiment.
[0053] See Figure 1 The capillary perforation control method of this embodiment includes the following steps S1 to S5.
[0054] S1. Before piercing the tube blank, extract the "historical optimized piercing three-data combination" corresponding to the product specification from the production database (searched using "product specification" as the keyword) according to the product specification of the target formed tube.
[0055] The specifications mentioned here mainly refer to the material, diameter, and wall thickness of the capillary tube.
[0056] The target forming tube refers to the tube that is about to be perforated and formed.
[0057] The variety and specifications of the target formed tube are obtained by the production process control computer from the production scheduling system via the network.
[0058] The production database is a database system specifically used to store and record on-site production data. It stores historical optimized perforation ternary data combinations corresponding to various types and specifications of capillary tubes. These historical optimized perforation ternary data combinations are the data structure of the perforation ternary data combinations.
[0059] The historical optimized perforation ternary data set refers to the perforation ternary data set obtained by correcting historical production data. The specific correction method can be found in step S5 below. It should be noted that the historical optimized perforation ternary data set is set separately for different varieties and specifications of capillary tubes; that is, a corresponding historical optimized perforation ternary data set is set for each variety and specification of capillary tube.
[0060] S2, based on the historical optimized punched ternary data combination, a brand new punched ternary data combination is constructed according to the pre-designed ternary data construction strategy. This brand new punched ternary data combination is called the "practical application punched ternary data combination".
[0061] The practical application of the punched three-data combination is the data structure of the punched three-data combination.
[0062] Guided by the aforementioned ternary data construction strategy, the ternary data nodes ranked higher in the actual application of the perforated ternary data combination are those ranked higher in the historical optimized perforated ternary data combination, while the ternary data nodes ranked lower in the actual application of the perforated ternary data combination are those ranked lower in the historical optimized perforated ternary data combination. In this way, the wall thickness of the capillary head and tail can be controlled as much as possible based on the historical optimized perforated ternary data combination, so as to reduce the deviation of the wall thickness at the head and tail of the perforated capillary.
[0063] The three-data construction strategy includes the following steps S21 to S26.
[0064] S21, estimate the total length of the target forming tube after perforation.
[0065] It should be noted that estimating the total length of the target shaped tube after perforation is existing technology, and the specific method of estimation is common knowledge known to those skilled in the art.
[0066] S22, divide the estimated total length of the target formed capillary after perforation by the adjustment cycle length. The resulting value is the number of ternary data nodes required in the actual application perforation ternary data combination to be constructed. This number is called the "node construction number".
[0067] It should be noted that the division performed here is integer division, and the final number of nodes is an integer.
[0068] S23. Compare the number of nodes constructed with the number of nodes in the historical optimized perforated three-data combination, and obtain the difference between the two. The absolute value of this difference is called the number of node changes.
[0069] It should be noted that the number of nodes mentioned here refers to the number of three-element data nodes in the historical optimized perforation three-element data combination.
[0070] S24. If the number of nodes constructed is equal to the number of nodes in the historical optimized perforated ternary data combination, then the historical optimized perforated ternary data combination is directly used as the actual application perforated ternary data combination.
[0071] S25. If the number of nodes constructed is greater than the number of nodes in the historical optimized perforated ternary data combination, then a new perforated ternary data combination is constructed based on the historical optimized perforated ternary data combination. According to the number of node changes, a ternary data node with the number of node changes is added at the node sorting midpoint of the new perforated ternary data combination. The added ternary data node is a "copy of the ternary data node at the node sorting midpoint of the historical optimized perforated ternary data combination". Then, the length position of all ternary data nodes in the new perforated ternary data combination is adjusted for adaptation. Finally, the newly constructed perforated ternary data combination is used as the perforated ternary data combination for actual application.
[0072] S26. If the number of nodes constructed is less than the number of nodes in the historical optimized perforated ternary data combination, then a new perforated ternary data combination is constructed based on the historical optimized perforated ternary data combination. According to the number of nodes that have changed, the ternary data nodes with the changed number of nodes in the middle of the sorting in the new perforated ternary data combination are deleted. Then, the length position of all ternary data nodes in the new perforated ternary data combination is adjusted for adaptation. Finally, the newly constructed perforated ternary data combination is used as the perforated ternary data combination for actual application.
[0073] It should be noted that the adaptive sorting adjustment refers to setting the length position in the three-dimensional data node to the value obtained by multiplying the sorting number by the adjustment period length.
[0074] Furthermore, after completing the construction of the actual application perforation ternary data set, this actual application perforation ternary data set is used as the new historical optimized perforation ternary data set to replace the historical optimized perforation ternary data set originally stored in the production database that corresponds to the capillary tube of the aforementioned variety and specification.
[0075] S3, the tube blank enters the piercing mill for piercing. During the piercing process, the roller gap and mandrel extension of the piercing mill are dynamically adjusted according to the actual application piercing three-dimensional data combination.
[0076] S4, during the perforation process, detects the actual wall thickness data of the perforated capillary.
[0077] Specifically, S4 includes the following steps S41 to S42.
[0078] S41, During the piercing process, when the pierced tube exits the piercing machine, the online wall thickness detection device installed at the piercing machine exit is used to actually detect the circumferential wall thickness data of the tube after each dynamic adjustment, and calculate the average value of the circumferential wall thickness data after each dynamic adjustment. This average value is called the "average wall thickness after one dynamic adjustment".
[0079] S42. After all perforations are completed, all the obtained average wall thicknesses after one dynamic adjustment are arranged and combined into an ordered data set according to the order of detection. This data set is called the actual average wall thickness data set of the capillary tube.
[0080] The aforementioned dynamic adjustment refers to an adjustment made to the roll gap and mandrel extension of the piercing machine based on the piercing ternary data of one of the ternary data nodes in the actual application piercing ternary data combination.
[0081] The "circumferential wall thickness data after one dynamic adjustment" mentioned here refers to the circumferential wall thickness data at a cross-section of the pierced tube obtained after one dynamic adjustment of the roller gap and mandrel extension of the piercing machine based on the actual application piercing three-element data combination. In other words, during the piercing process, each time the piercing machine dynamically adjusts the roller gap and mandrel extension, the online wall thickness detection device detects the circumferential wall thickness data at a cross-sectional position of the pierced tube obtained after that dynamic adjustment.
[0082] The online wall thickness detection device is a device installed at the outlet of the perforating machine that can measure the wall thickness of the capillary tube without contact. The online wall thickness detection device has several non-contact thickness probes, usually 2 to 13 thickness probes. These thickness probes are evenly arranged around the circumference of the capillary tube, so that the wall thickness at the same cross-sectional position of the capillary tube can be detected.
[0083] It should be noted that the correspondence between "the average wall thickness after one dynamic adjustment in the actual wall thickness average data set" and "the three element nodes in the perforation three element data combination" mentioned in this article refers to the correspondence of sorting numbers. For example, "the average wall thickness after one dynamic adjustment ranked first in the actual wall thickness average data set" corresponds to "the three element node ranked first in the perforation three element data combination", "the average wall thickness after one dynamic adjustment ranked second in the actual wall thickness average data set" corresponds to "the three element node ranked second in the perforation three element data combination", and so on. This correspondence is called the sorting correspondence.
[0084] S5. Based on the actual wall thickness data of the perforated capillary tube, optimize and correct the historical optimized perforation three-data combination stored in the production database that corresponds to the variety and specifications of the capillary tube.
[0085] Specifically, the actual wall thickness data used as the basis for correction here is the set of average actual wall thickness data. The optimization correction of the historical optimized perforation three-data combination is carried out according to a pre-set correction strategy, which is referred to as the "three-data correction strategy".
[0086] The three-data correction strategy includes:
[0087] For each ternary data node in the historical optimized piercing ternary data combination, determine the roll gap correction amount and the mandrel extension amount correction amount for that ternary data node. Then, use the roll gap correction amount to correct the roll gap adjustment amount in the ternary data node, and use the mandrel extension amount correction amount to correct the mandrel extension amount adjustment amount in the ternary data node.
[0088] The roll gap correction is represented by ΔE, and the mandrel extension correction is represented by ΔR.
[0089] The roll gap correction amount ΔE is based on the formula The formula is used to calculate and determine the value of the roll gap correction, where ΔE is the inlet cone angle of the piercing roll of the piercing mill, α2 is the deviation between the actual wall thickness and the target thickness, and α is the value of the deviation between the actual wall thickness and the target thickness. lgt2 The angle of the top rolling cone.
[0090] It should be noted that if the piercing machine inlet has only one inlet cone, the inlet cone angle α2 of the piercing machine piercing roller is a single cone angle; if the piercing machine inlet has two inlet cones, the inlet cone angle α2 of the piercing machine piercing roller is a double cone angle. The value range of the inlet cone angle α2 is 1.3 to 5°. The deviation value ΔS between the actual wall thickness and the target is the difference between "the circumferential wall thickness data after one dynamic adjustment corresponding to the sorting of the three data nodes in the actual wall thickness mean data set" and "the target wall thickness corresponding to the variety and specification of the current pierced capillary".
[0091] The correction amount ΔR for the mandrel extension is calculated and determined according to the formula ΔR=0.5×ΔE / tan(α2), where ΔR is the correction amount for the mandrel extension, α2 is the angle of the cone surface at the entrance of the piercing roller of the piercing machine, and ΔE is the correction amount for the roller gap.
[0092] The significance of the formula for calculating the mandrel extension correction is that the adjustment values of the piercing mill roll gap and mandrel extension are adjusted according to the adjustment ratio of 2tan(α2):1. In this way, the roll gap and mandrel positions can match each other during the piercing process, thereby avoiding the internal folding defect of the tube after piercing, ensuring the quality of the inner surface of the tube, and ensuring the stability of the piercing process and avoiding steel jamming.
[0093] It should be noted that the "correction" mentioned here essentially involves adding the correction amount to the value of the object to be corrected, and then replacing the value of the object to be corrected with the sum. Specifically, in this embodiment, correcting the roll gap adjustment amount in the three-dimensional data node using the roll gap correction amount ΔE essentially involves adding the roll gap correction amount ΔE to the roll gap adjustment amount value in the three-dimensional data node, and then replacing the roll gap adjustment amount value in the three-dimensional data node with the sum. Similarly, correcting the mandrel extension adjustment amount in the three-dimensional data node using the mandrel extension correction amount ΔR essentially involves adding the mandrel extension correction amount ΔR to the mandrel extension adjustment amount value in the three-dimensional data node, and then replacing the mandrel extension adjustment amount value in the three-dimensional data node with the sum.
[0094] It should be noted that the capillary piercing control method of this embodiment is set in the production process control computer in the form of a program. During the process of dynamically adjusting the adjustment amount of the roller gap and the mandrel extension of the piercing machine, the capillary piercing control method of this embodiment is implemented by the production process control computer executing the program.
[0095] In the tube piercing control method of this embodiment, during the piercing process of the tube blank entering the piercing mill, the adjustment amount of the roller gap and mandrel extension of the piercing mill is dynamically adjusted according to the actual application piercing three data combination. This allows for dynamic adjustment and control of the tube wall thickness during the piercing process, ensuring that the wall thickness of the pierced tube is uniform in the longitudinal direction. This benefits the subsequent seamless steel pipe production process, improves the uniformity of the wall thickness of the final seamless steel pipe, and ultimately enhances the quality level of the finished seamless steel pipe.
[0096] In the capillary piercing control method of this embodiment, when dynamically adjusting the roll gap and mandrel extension during the piercing process, the adjustment amounts of the roll gap and mandrel extension are adjusted according to the adjustment ratio of 2tan(α2):1. In this way, the positions of the roll gap and mandrel can match each other during the piercing process, thereby avoiding the internal folding defect of the capillary after piercing, ensuring the quality of the inner surface of the capillary, and ensuring the stability of the piercing process and avoiding steel jamming.
[0097] In the capillary perforation control method of this embodiment, during the perforation process, when the perforated capillary exits the perforation machine outlet, an online wall thickness detection device is used to actually detect the wall thickness data of the capillary, thereby realizing real-time feedback of the capillary wall thickness, which is beneficial to the subsequent control of the capillary wall thickness.
[0098] In the capillary piercing control method of this embodiment, historical optimized piercing ternary data combinations for various types and specifications of capillary tubes are pre-stored in the production database. Before piercing, the historical optimized piercing ternary data combinations are extracted and the actual application piercing ternary data combinations are constructed. Then, the roll gap and mandrel extension are dynamically adjusted according to the actual application piercing ternary data combinations. This approach helps to adjust the roll gap and mandrel extension to the appropriate adjustment amount for the type and specification of the capillary tube before piercing, avoiding large wall thickness deviations when changing specifications and rolling, thereby enabling better control of the capillary tube wall thickness.
[0099] In addition, when optimizing and correcting the combination of historical perforation three data elements, the correction amount is determined by formula calculation, which facilitates automated adjustment.
[0100] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for controlling capillary perforation to improve longitudinal wall thickness uniformity, characterized in that: include: S1. Before piercing the tube blank, obtain the historical optimized piercing three-dimensional data combination corresponding to the target forming tube according to the variety and specifications of the tube. The historical optimized punched three-data combination is the data structure of the punched three-data combination; The perforation three-dimensional data combination is composed of n three-dimensional data nodes arranged and combined. The three-dimensional data nodes include perforation three-dimensional data, which are length point, roll gap adjustment amount and mandrel forward extension adjustment amount, and n is a natural number. S2, construct the actual application of the punching three-data combination based on the historical optimized punching three-data combination; S3, the tube blank enters the piercing mill for piercing. During the piercing process, the roller gap and mandrel extension of the piercing mill are dynamically adjusted according to the actual application piercing three data combination. S4, during the perforation process, the actual wall thickness data of the perforated capillary is obtained; S5, using the actual wall thickness data of the perforated capillary as the basis for correction, optimize and correct the historical optimized perforation three-data combination corresponding to the variety and specifications of the capillary. S5 further includes: the optimization correction of the historical optimized perforation three-element data combination is performed according to a preset three-element data correction strategy, the three-element data correction strategy including: For each ternary data node in the historical optimized piercing ternary data combination, determine the roll gap correction amount and the mandrel extension amount correction amount. Then, use the roll gap correction amount to correct the roll gap adjustment amount in the ternary data node, and use the mandrel extension amount correction amount to correct the mandrel extension amount adjustment amount in the ternary data node. The roll gap correction amount is based on the formula The formula is used to calculate and determine the value of the roll gap correction, where ΔE is the inlet cone angle of the piercing roll of the piercing mill, α2 is the deviation between the actual wall thickness and the target thickness, and α is the value of the deviation between the actual wall thickness and the target thickness. lgt2 The angle of the rolling cone at the top; The correction amount for the forward extension of the top head is based on the formula. The formula is used to calculate and determine the amount of correction for the forward extension of the mandrel, where ΔR is the angle of the cone surface at the entrance of the piercing roller of the piercing machine, α2 is the angle of the cone surface at the entrance of the piercing roller, and ΔE is the correction for the roller gap.
2. The capillary perforation control method for improving longitudinal wall thickness uniformity according to claim 1, characterized in that: In the constructed practical application perforated ternary data combination, the ternary data nodes that are ranked first are the ternary data nodes that are ranked first in the historical optimized perforated ternary data combination, and the ternary data nodes that are ranked last in the practical application perforated ternary data combination are the ternary data nodes that are ranked last in the historical optimized perforated ternary data combination.
3. The capillary perforation control method for improving longitudinal wall thickness uniformity according to claim 1, characterized in that: The actual application of the perforated three-dimensional data combination is constructed according to a preset three-dimensional data construction strategy, which includes: S21, estimate the total length of the target forming tube after perforation in advance; S22, the estimated total length of the target formed capillary after perforation is divided by the adjustment cycle length, and the resulting value is the number of nodes constructed. S23, compare the number of nodes constructed with the number of nodes in the historical optimized perforation three-data combination, and take the absolute value of the difference in the number of nodes as the number of node changes; S24. If the number of nodes constructed is equal to the number of nodes in the historical optimized perforated ternary data combination, then the historical optimized perforated ternary data combination shall be used as the actual application perforated ternary data combination. S25. If the number of nodes constructed is greater than the number of nodes in the historical optimized perforated ternary data combination, then a new perforated ternary data combination is constructed based on the historical optimized perforated ternary data combination. According to the number of node changes, ternary data nodes are added at the midpoint of the node sorting in the new perforated ternary data combination. The added ternary data nodes are copies of the ternary data nodes at the midpoint of the node sorting in the historical optimized perforated ternary data combination. Then, the length positions of all ternary data nodes in the new perforated ternary data combination are adjusted for adaptation. Finally, the newly constructed perforated ternary data combination is used as the perforated ternary data combination for actual application. S26. If the number of nodes constructed is less than the number of nodes in the historical optimized perforated ternary data combination, then a new perforated ternary data combination is constructed based on the historical optimized perforated ternary data combination. According to the number of nodes changed, the ternary data nodes in the middle of the sorting in the new perforated ternary data combination are deleted. Then, the length position of all ternary data nodes in the new perforated ternary data combination is adjusted for adaptive sorting. Finally, the newly constructed perforated ternary data combination is used as the perforated ternary data combination for actual application.
4. The capillary perforation control method for improving longitudinal wall thickness uniformity according to claim 1, characterized in that: S2 further includes: after completing the construction of the actual application perforation ternary data combination, replacing the historical optimized perforation ternary data combination corresponding to the capillary of the variety specification with the actual application perforation ternary data combination as the new historical optimized perforation ternary data combination.
5. The capillary perforation control method for improving longitudinal wall thickness uniformity according to claim 1, characterized in that: S4 includes: S41, During the piercing process, when the pierced tube exits the piercing machine outlet, the circumferential wall thickness data of the tube after each dynamic adjustment is actually detected, and the average wall thickness after each dynamic adjustment is calculated. S42. After the perforation is completed, all the obtained average wall thickness values after one dynamic adjustment are arranged and combined into an ordered data set according to the order of detection. This data set is the actual average wall thickness data set of the capillary tube.
6. The capillary perforation control method for improving longitudinal wall thickness uniformity according to claim 5, characterized in that: In S41, the circumferential wall thickness data after each dynamic adjustment of the actual detected capillary is implemented by an online wall thickness detection device; The online wall thickness detection device is a device installed at the outlet of the perforating machine that can measure the capillary wall thickness without contact. The online wall thickness detection device has several non-contact thickness measuring probes, which are evenly arranged around the circumference of the capillary.