Large-diameter titanium and titanium alloy pipe intelligent forming method and system

Abstract

The application provides a large-diameter titanium and titanium alloy pipe intelligent forming method and system. It relates to the field of computer integrated manufacturing technology, including a process setting module generating a process flow according to pipe design requirements, dividing the pipe into multiple forming control partitions, and setting partition forming targets; a partition monitoring module acquiring process parameters of each partition and collecting them according to the partitions; a state recognition module calculating partition geometric size deviations, constructing quality deviation indexes, and judging whether the quality deviation indexes are out of limits; a cross-process parameter adjustment module generating partition parameter correction amounts and compensation amounts according to a preset cross-process compensation relationship when the quality deviation is out of limits, and issuing the parameter correction amounts and compensation amounts to a forming device by an execution control module. The large-diameter titanium and titanium alloy pipe intelligent forming method and system implement differentiated forming control on different forming control partitions, form cross-process closed-loop forming control based on partition quality deviations, and thus improve the size precision and batch production consistency of large-diameter titanium and titanium alloy pipes.

Description

Technical Field

[0001] This invention relates to the field of computer-integrated manufacturing technology, specifically to a method and system for intelligent forming of large-diameter titanium and titanium alloy pipes. Background Technology

[0002] Titanium and titanium alloys possess high specific strength, excellent corrosion resistance, and superior fatigue resistance, and are widely used in aerospace, marine engineering, petrochemical, and nuclear industries. With the continuous development of large-scale, long-life, and high-safety engineering equipment, the demand for large-diameter titanium and titanium alloy pipes is increasing in critical components such as high-pressure transmission pipelines, deep-sea oil and gas extraction risers, and nuclear power plant heat exchange tubes. These pipes often simultaneously possess characteristics such as large diameter, thick walls, high strength, and high resilience, making plastic deformation during forming difficult, the process window narrow, and requiring extremely high uniformity of microstructure and geometric precision.

[0003] In existing technologies, several intelligent process design and parameter optimization schemes combining computer-integrated manufacturing technology have been proposed for the forming process of titanium and titanium alloy tubes and forgings. Chinese invention patent application number 202110630623.7 discloses an intelligent forming method and system for high-resilience titanium alloy tubes. This method introduces knowledge engineering methods into the development of titanium alloy steam generator tube bending forming processes, constructing a process database, knowledge base, and instance library. Combined with a simulation analysis module, it enables rapid generation and simulation optimization of eccentricity forming parameters for high-resilience thin tubes, reducing the number of experiments and improving process design efficiency. Chinese invention patent application number 202510428529.1 discloses a radial forging method and system for titanium alloys based on radial reduction rate and feed rate. By setting the initial temperature, radial reduction rate, and feed rate ranges, and combining surface morphology detection and forging simulation models, the method compares the deformation uniformity distribution between actual and simulated values, thereby optimizing the model and process parameters to improve the deformation uniformity and process parameter control accuracy of radial forging. Chinese invention patent application number 202511345080.9 discloses a collaborative optimization method for radial forging reduction rate of titanium alloy based on material testing. By collecting multi-dimensional material performance parameters such as temperature, strain rate, dynamic recrystallization volume fraction, dislocation density and size change, a multi-objective collaborative optimization model for reduction rate is established. The reduction rate optimization scheme is generated by using entropy weight method, fuzzy decision and Pareto front search, and combined with online monitoring and real-time correction mechanism, the reduction rate in the radial forging process is collaboratively optimized and controlled.

[0004] However, the aforementioned existing technologies still have the following common defects: In actual production, existing technologies mostly follow pre-set process routes and parameters, lacking refined quality assessment and cross-process coordination and control methods for the circumferential wall thickness unevenness, ellipticity and axial straightness cumulative deviations that are easily generated during the multi-pass and multi-process forming of large-diameter titanium and titanium alloy pipes. They have not established a quantitative evaluation mechanism for forming state based on multi-source online monitoring data of different regions and an adaptive adjustment mechanism for regional parameters, making it difficult to correct forming deviations at different axial and circumferential positions in a timely and precise manner. As a result, the overall dimensional accuracy and local microstructure consistency of large-diameter titanium and titanium alloy pipes are difficult to be stably guaranteed under mass production conditions. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an intelligent forming method and system for large-diameter titanium and titanium alloy pipes. By using cross-process parameter adaptive compensation control based on zoned multi-source online monitoring and quality deviation index driven by the system, the problem of unstable and uncontrollable forming quality of large-diameter titanium and titanium alloy pipes during multi-process forming is solved.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an intelligent forming system for large-diameter titanium and titanium alloy pipes, comprising:

[0007] The process setting module includes a process generation unit and a partition setting unit. The process generation unit is used to set a process flow covering at least two forming processes among extrusion, reaming, radial forging, heat treatment and straightening, according to the design requirements of large-diameter titanium and titanium alloy tubes. The partition setting unit divides the large-diameter titanium and titanium alloy tubes to be formed into several forming control partitions along the axial and circumferential directions according to the geometric dimensions and forming accuracy requirements of the large-diameter titanium and titanium alloy tubes, and sets partition forming targets for each forming control partition.

[0008] The partition monitoring module is used to perform online monitoring of the large-diameter titanium and titanium alloy pipes located in each forming control partition during the process flow, and to collect process parameters of each forming control partition. The partition monitoring module performs partitioned collection of the process parameters according to the forming control partition to form partition monitoring data.

[0009] The status recognition module is used to calculate the partition status parameters of each forming control partition based on the partition monitoring data and the partition forming target. The partition status parameters include at least the geometric dimension deviation of each forming control partition. The status recognition module calculates the degree of deviation between the partition status parameters and the partition forming target based on the partition status parameters, and determines whether each partition status parameter is within a preset allowable range based on the degree of deviation.

[0010] The cross-process parameter adjustment module is used to determine the cross-process compensation relationship between the current process and at least one subsequent process in the process flow according to the degree of deviation when at least one partition status parameter exceeds the preset allowable range, and to calculate the partition parameter correction amount of the forming control partition in the current process and the partition parameter compensation amount in each subsequent process based on the cross-process compensation relationship.

[0011] The execution control module is used to send the partition parameter correction amount and the partition parameter compensation amount to the forming equipment of the corresponding process, control the forming equipment to perform differentiated forming control on each forming control partition according to the process flow, continuously acquire updated partition monitoring data during the forming process and feed it back to the status recognition module, and adjust the partition parameter correction amount and partition parameter compensation amount of each forming control partition in real time based on the updated partition monitoring data, forming a real-time closed-loop control across processes.

[0012] Preferably, the partition setting unit divides the large-diameter titanium and titanium alloy pipe into an end compensation partition and a middle stable forming partition along the axial direction based on the geometric dimension distribution of the large-diameter titanium and titanium alloy pipe in the axial and circumferential directions. Based on the distribution characteristics of ellipticity and uneven wall thickness, the end compensation partition and the middle stable forming partition are further divided circumferentially to form the forming control partition. The forming target of the partition includes the wall thickness target, ellipticity target and straightness target to ensure the quality control of each partition.

[0013] Preferably, the zone monitoring module includes an infrared temperature sensor, a forming load sensor, a displacement sensor, and a laser diameter gauge, used to acquire the process parameters through the online monitoring. The process parameters include zone temperature, zone forming load, zone displacement, and zone geometry.

[0014] Preferably, the zone monitoring data includes the zone outer diameter, zone wall thickness, and axial deflection, and the calculation of the geometric deviation includes the following steps:

[0015] S41. Interpolate and smooth the outer diameter and wall thickness of the partition to obtain the circumferential outer diameter distribution and circumferential wall thickness distribution;

[0016] S42. The ellipticity deviation of each forming control zone is calculated based on the circumferential outer diameter distribution, and the wall thickness deviation of each forming control zone is calculated based on the circumferential wall thickness distribution.

[0017] S43. The partition ellipticity deviation, the partition wall thickness deviation, and the partition axial straightness contribution calculated from the axial deflection are taken as the geometric dimension deviation.

[0018] Preferably, the state recognition module includes a partitioned forming quality assessment unit. The partitioned forming quality assessment unit is used to normalize the partitioned ellipticity deviation, partitioned wall thickness deviation, and partitioned axial straightness contribution of each forming control partition to form a normalized deviation value. The normalized deviation value is then weighted and combined according to a preset weight to obtain the quality deviation index of each forming control partition. The degree of deviation is the quality deviation index of each forming control partition.

[0019] Preferably, the calculation of the partition parameter correction amount and the partition parameter compensation amount includes the following steps:

[0020] S61. When the quality deviation index of the forming control zone exceeds a preset upper limit, the total partition quality compensation amount of the forming control zone is obtained based on the quality deviation index.

[0021] S62. Based on the cross-process compensation relationship, determine the quality compensation allocation coefficients corresponding to the current process and each subsequent process. The cross-process compensation relationship is predetermined based on the correction capability of each forming process for the geometric deviation and the available adjustment range of the corresponding forming equipment.

[0022] S63. Based on the total partition mass compensation amount and the mass compensation allocation coefficient, the total partition mass compensation amount is converted into the partition parameter correction amount of the forming control partition in the current process and the partition parameter compensation amount in each subsequent process, so as to simultaneously suppress the accumulation of uneven wall thickness and axial straightness deviation of the forming control partition.

[0023] Preferably, the partition parameter correction amount and partition parameter compensation amount include at least one or more of radial reduction rate, feed rate, heating power and straightening torque, and the forming equipment includes at least one of extrusion press, radial forging machine, heating device and straightening device.

[0024] Preferably, at least one step in the process flow includes multiple loading passes, the partition parameter correction amount takes effect in the subsequent loading passes corresponding to the current step, and the partition parameter compensation amount takes effect in the initial loading pass corresponding to the subsequent step.

[0025] Intelligent forming methods for large-diameter titanium and titanium alloy pipes include:

[0026] S1. Based on the design requirements of large-diameter titanium and titanium alloy tubes, set a process flow covering at least two forming processes among extrusion, reaming, radial forging, heat treatment and straightening. Based on the axial and circumferential geometric dimensions and forming accuracy requirements of the large-diameter titanium and titanium alloy tubes, divide the large-diameter titanium and titanium alloy tubes to be formed into several forming control zones along the axial and circumferential directions, and set zone forming targets for each forming control zone.

[0027] S2. In each forming step of the process flow, the large-diameter titanium and titanium alloy pipes located in each forming control zone are monitored online, the process parameters of each forming control zone are collected, and the process parameters are collected by zone according to the forming control zone to form zone monitoring data.

[0028] S3. Based on the partition monitoring data and the partition forming target, calculate the partition status parameters of each forming control partition. The partition status parameters include at least the geometric dimension deviation of each forming control partition. Determine the degree of deviation of each forming control partition based on the partition status parameters. Determine whether the partition status parameters are within the preset allowable range based on the degree of deviation.

[0029] S4. When it is determined that at least one partition status parameter exceeds the preset allowable range, the cross-process compensation relationship between the current process and at least one subsequent process in the process flow is determined according to the degree of deviation, and the partition parameter correction amount of the forming control partition in the current process and the partition parameter compensation amount in each subsequent process are calculated based on the cross-process compensation relationship.

[0030] S5. The partition parameter correction amount and the partition parameter compensation amount are sent to the forming equipment of the corresponding process, and the forming equipment is controlled to implement differentiated forming control for each forming control partition according to the process flow. During the forming process, the updated partition monitoring data is continuously acquired and S3 and S4 are repeatedly executed. Based on the updated partition monitoring data, the partition parameter correction amount and partition parameter compensation amount of each forming control partition are adjusted in real time to form a real-time closed-loop control across processes.

[0031] This invention provides an intelligent forming method and system for large-diameter titanium and titanium alloy pipes. It offers the following advantages:

[0032] This intelligent forming method and system for large-diameter titanium and titanium alloy tubes significantly improves the precision control and intelligence of the forming process. By introducing an overall process flow plan covering at least two of the processes—extrusion, reaming, radial forging, heat treatment, and straightening—at the process setting stage, and dividing the tube into forming control zones along the axial and circumferential directions, with individual forming targets set for each zone, this invention transforms the coarse control of the entire tube into precise control by zone. Combined with multi-source online monitoring and zone status identification, it can acquire process parameters such as temperature, load, displacement, and geometric dimensions of each zone in real time. These process parameters are then converted into zone status parameters and deviation degrees, including geometric dimension deviations. This enables quantitative characterization and real-time judgment of typical defects in large-diameter titanium tubes, such as ellipticity, uneven wall thickness, and straightness, significantly reducing the lag of relying on experience-based debugging and offline detection, and improving the consistency and controllability of forming quality.

[0033] Furthermore, this invention, by setting up a cross-process parameter adjustment module, when a certain partition state is found to deviate from the preset allowable range, does not only passively correct it within the current process, but also constructs a cross-process compensation relationship between the current process and at least one subsequent process based on the degree of deviation. It calculates the partition parameter correction amount for the current process and the partition parameter compensation amount for the subsequent processes, and the execution control module applies these parameters to the extruder, radial forging machine, heating device, and straightening equipment, etc., to achieve coordinated adjustment and differentiated loading of partition parameters across multiple processes. Combined with continuously updated partition monitoring data during the forming process, a real-time closed-loop control mechanism is formed across processes. This allows for compensation through subsequent processes when defects are still in their nascent stage, suppressing the accumulation of uneven wall thickness, excessive ellipticity, and axial straightness deviations, reducing scrap rates and rework frequency, while also lowering trial production and setup costs, and improving the automation, stability, and overall economy of large-diameter titanium and titanium alloy tube forming production. Attached Figure Description

[0034] Figure 1 This is a block diagram of the system functional modules of the present invention;

[0035] Figure 2 This is a flowchart of the partition quality assessment process of the present invention;

[0036] Figure 3 This is a flowchart of the cross-process compensation and parameter adjustment process of the present invention;

[0037] Figure 4 This is a flowchart of the method of the present invention. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1

[0040] like Figure 1 and Figure 4As shown, this embodiment of the invention provides an intelligent forming system for large-diameter titanium and titanium alloy tubes, including a process setting module. The process setting module includes a process generation unit and a partition setting unit. The process generation unit is used to set a process flow covering at least two forming processes among extrusion, reaming, radial forging, heat treatment, and straightening, according to the design requirements of the large-diameter titanium and titanium alloy tubes. The partition setting unit divides the large-diameter titanium and titanium alloy tubes to be formed into several forming control zones along the axial and circumferential directions according to the geometric dimensions and forming accuracy requirements of the large-diameter titanium and titanium alloy tubes, and sets a partition forming target for each forming control zone.

[0041] In this embodiment, the intelligent forming system for large-diameter titanium and titanium alloy pipes consists of an industrial control computer or programmable logic controller (PLC), along with connected sensor acquisition units and actuator drive units. The process setting module, zone monitoring module, status identification module, cross-process parameter adjustment module, and execution control module are deployed as software function blocks within the industrial control computer. They interact with the extruder, reaming equipment, radial forging machine, heating device, and straightening equipment via industrial Ethernet, fieldbus, or other communication interfaces, and issue control commands accordingly. In this embodiment, the preferred process flow is a combination of extrusion—reaming—radial forging—heat treatment—straightening. However, for pipes with different specifications and performance requirements, at least two forming processes can be combined as needed.

[0042] Based on the axial and circumferential geometric dimensions of large-diameter titanium and titanium alloy pipes, the partitioning unit divides the large-diameter titanium and titanium alloy pipes into end compensation partitions and middle stable forming partitions along the axial direction. Based on the distribution characteristics of ellipticity and uneven wall thickness, the end compensation partitions and middle stable forming partitions are further divided circumferentially to form the forming control partitions. The forming targets of each partition include wall thickness targets, ellipticity targets, and straightness targets to ensure the quality control of each partition.

[0043] In one specific implementation, for a titanium alloy tube with an outer diameter of 800mm, a wall thickness of 40mm, and a finished length of 6000mm, the area 500mm from each end can be designated as an end compensation zone, and the middle 5000mm zone as a central stable forming zone. Circumferentially, several circumferential zones can be divided at 90° or 45° intervals, ensuring each forming control zone has a clearly defined geometric position range in both the axial and circumferential directions. The ellipticity and straightness targets for the end compensation zones are set relatively more stringent to suppress end taper and bending defects; the wall thickness target for the central stable forming zone serves as the primary constraint for controlling wall thickness uniformity. This embodiment is only a typical division method; in practical applications, the end compensation length, the number of circumferential divisions, and the target values ​​for each zone should be adjusted according to the tube specifications and technical standards.

[0044] The zone monitoring module is used to perform online monitoring of large-diameter titanium and titanium alloy pipes located in each forming control zone during the process flow. It collects process parameters for each forming control zone and then aggregates the process parameters according to the forming control zone to form zone monitoring data.

[0045] Specifically, when collecting various process parameters, each data point is appended with a corresponding forming control zone identifier and the time of acquisition. Based on the forming control zone identifier, the zone monitoring module categorizes, summarizes, and organizes the temperature, forming load, displacement, and geometric dimension data within the same forming control zone, forming a zone monitoring data set indexed by the forming control zone. In subsequent status identification and parameter adjustment processes, forming quality assessment and parameter correction are performed separately for each forming control zone, rather than evaluating the entire pipe as a whole.

[0046] In this embodiment, the process parameters are grouped and aggregated. This means that when collecting the zone temperature, zone forming load, zone displacement and zone geometry, each measurement data is attached with its corresponding forming control zone identifier: axial position interval number and circumferential zone number. The zone monitoring module classifies and summarizes the original measurement data according to the forming control zone identifier, thereby forming a zone monitoring data set indexed by the forming control zone, which is used for subsequent zone forming state identification and parameter adjustment.

[0047] The zone monitoring module includes an infrared temperature sensor, a forming load sensor, a displacement sensor, and a laser diameter gauge, which are used to acquire process parameters through online monitoring. These process parameters include zone temperature, zone forming load, zone displacement, and zone geometry.

[0048] The status recognition module is used to calculate the status parameters of each forming control zone based on the zone monitoring data and the zone forming target. The zone status parameters include at least the geometric dimension deviation of each forming control zone. The status recognition module calculates the degree of deviation between the zone status parameters and the zone forming target based on the degree of deviation, and determines whether the status parameters of each zone are within the preset allowable range based on the degree of deviation.

[0049] The zone monitoring data includes the zone outer diameter, zone wall thickness, and axial deflection. The calculation of geometric deviations includes the following steps:

[0050] S41. Interpolate and smooth the outer diameter and wall thickness of the partition to obtain the circumferential outer diameter distribution and circumferential wall thickness distribution.

[0051] S42. The ellipticity deviation of each forming control zone is calculated based on the circumferential outer diameter distribution, and the wall thickness deviation of each forming control zone is calculated based on the circumferential wall thickness distribution.

[0052] S43. The ellipticity deviation of the zone, the wall thickness deviation of the zone, and the contribution of the axial straightness of the zone calculated from the axial deflection are used as geometric dimensional deviations. The axial deflection is obtained through a deflection measuring device or an online shape measurement system arranged along the pipe axis. When processing the obtained axial deflection measurement points, the theoretical straightness reference of the pipe centerline is fitted using the least squares method, and the deflection deviation of each measurement point relative to the straightness reference is calculated. For any forming control zone, the maximum value and root mean square value of the deflection deviation within the axial range of that zone are used as the axial deflection characteristic value of that zone, and the axial straightness contribution of that zone is defined accordingly to characterize the degree of contribution of that zone to the axial straightness defects of the entire pipe.

[0053] The status recognition module includes a partitioned forming quality assessment unit. The partitioned forming quality assessment unit is used to normalize the partitioned ellipticity deviation, partitioned wall thickness deviation, and partitioned axial straightness contribution of each forming control partition to form a normalized deviation value. The normalized deviation value is then weighted and combined according to a preset weight to obtain the quality deviation index of each forming control partition. The degree of deviation is the quality deviation index of each forming control partition.

[0054] The preset weights are set based on the sensitivity of different forming control zones to ellipticity, wall thickness, and straightness, as well as the technical requirements of the final product. Specifically, for end compensation zones, the weights of ellipticity deviation and axial straightness contribution in the quality deviation index are increased; for central stable forming zones, the weight of wall thickness deviation is increased. The weights are calibrated through process experiments, simulation analysis, or historical production data statistics. In this embodiment, the quality deviation index is used to comprehensively reflect the overall deviation of a forming control zone in the three dimensions of ellipticity, wall thickness, and straightness. The larger the index value, the worse the forming quality of that zone.

[0055] The cross-process parameter adjustment module is used to determine the cross-process compensation relationship between the current process and at least one subsequent process in the process flow based on the degree of deviation when at least one partition status parameter exceeds the preset allowable range, and to calculate the partition parameter correction amount of the forming control partition in the current process and the partition parameter compensation amount in each subsequent process based on the cross-process compensation relationship.

[0056] In this embodiment, an allowable range for the quality deviation index is pre-set. When the quality deviation index of a certain forming control zone exceeds the allowable upper limit, the zone is deemed to require compensation adjustment. The total zone quality compensation amount is used to characterize the overall compensation intensity required for the forming control zone at the current moment. The magnitude of the total zone quality compensation amount is determined based on the extent to which the quality deviation index exceeds the allowable upper limit and process experience. The larger the total zone quality compensation amount, the more significant the process parameter adjustments required in subsequent processes to correct its forming quality deviation.

[0057] The calculation of partition parameter correction and partition parameter compensation includes the following steps:

[0058] S61. When the quality deviation index of the forming control zone exceeds the preset upper limit, the total zone quality compensation amount of the forming control zone is obtained based on the quality deviation index.

[0059] S62. Based on the cross-process compensation relationship, determine the quality compensation allocation coefficients corresponding to the current process and each subsequent process. The cross-process compensation relationship is predetermined based on the ability of each forming process to correct geometric deviations and the available adjustment range of the corresponding forming equipment.

[0060] Specifically, through finite element process simulation and small-batch trial production, the correction capabilities of the hole-expanding process, each radial forging process, and the straightening process for ellipticity deviation, wall thickness deviation, and straightness deviation were analyzed. Simultaneously, the adjustable ranges of parameters such as the reduction rate, feed rate, heating power, and straightening torque of the forming equipment in each process were considered to comprehensively determine the proportion each process could undertake in the compensation task, i.e., the quality compensation allocation coefficient. Generally, processes with strong correction capabilities and larger adjustable margins will be assigned a higher quality compensation proportion.

[0061] S63. Based on the total partition mass compensation amount and the mass compensation allocation coefficient, the total partition mass compensation amount is converted into the partition parameter correction amount of the forming control partition in the current process and the partition parameter compensation amount in each subsequent process, so as to simultaneously suppress the accumulation of uneven wall thickness and axial straightness deviation of the forming control partition. After obtaining the mass compensation amount corresponding to the current process and each subsequent process, the mass compensation amount is converted into specific process parameter adjustment amounts. Specifically, for the radial forging process, compensation is achieved by adjusting the radial reduction rate and feed rate corresponding to each forming control partition; for the heating process, the temperature distribution is changed by adjusting the heating power and holding time of each partition; for the straightening process, the straightness is corrected by adjusting the straightening torque and straightening roll gap of each partition. In this embodiment, the correspondence between the mass compensation amount and the process parameter adjustment amount can be pre-established based on the results of process experiments or simulation analysis, and the conversion is performed by linear mapping or segmented lookup table.

[0062] At least one step in the process flow includes multiple loading passes. The partition parameter correction amount is used to take effect in the subsequent loading passes of the corresponding current step, and the partition parameter compensation amount is used to take effect in the initial loading pass of the corresponding subsequent step.

[0063] The execution control module is used to send the partition parameter correction amount and partition parameter compensation amount to the forming equipment of the corresponding process, control the forming equipment to perform differentiated forming control on each forming control partition according to the process flow, continuously acquire updated partition monitoring data during the forming process and feed it back to the status recognition module, and adjust the partition parameter correction amount and partition parameter compensation amount of each forming control partition in real time based on the updated partition monitoring data, forming a real-time closed-loop control across processes.

[0064] The partition parameter correction amount and partition parameter compensation amount include at least one or more of radial reduction rate, feed rate, heating power and straightening torque, and the forming equipment includes at least one of extrusion press, radial forging machine, heating device and straightening device.

[0065] Intelligent forming methods for large-diameter titanium and titanium alloy pipes include:

[0066] S1. Based on the design requirements of large-diameter titanium and titanium alloy tubes, set a process flow covering at least two forming processes among extrusion, reaming, radial forging, heat treatment and straightening. Based on the axial and circumferential geometric dimensions and forming accuracy requirements of large-diameter titanium and titanium alloy tubes, divide the large-diameter titanium and titanium alloy tubes to be formed into several forming control zones along the axial and circumferential directions, and set zone forming targets for each forming control zone.

[0067] S2. In each forming process of the process flow, large-diameter titanium and titanium alloy pipes located in each forming control zone are monitored online, process parameters of each forming control zone are collected, and process parameters are collected by forming control zone to form zone monitoring data.

[0068] S3. Based on the zone monitoring data and the zone forming target, calculate the zone status parameters of each forming control zone. The zone status parameters include at least the geometric dimension deviation of each forming control zone. Determine the degree of deviation of each forming control zone based on the zone status parameters, and judge whether the zone status parameters are within the preset allowable range based on the degree of deviation.

[0069] S4. When it is determined that at least one partition status parameter exceeds the preset allowable range, the cross-process compensation relationship between the current process and at least one subsequent process in the process flow is determined according to the degree of deviation, and the partition parameter correction amount of the forming control partition in the current process and the partition parameter compensation amount in each subsequent process are calculated based on the cross-process compensation relationship.

[0070] S5. Send the partition parameter correction amount and partition parameter compensation amount to the forming equipment of the corresponding process, and control the forming equipment to implement differentiated forming control for each forming control partition according to the process flow. During the forming process, continuously acquire the updated partition monitoring data and repeat S3 and S4. Based on the updated partition monitoring data, adjust the partition parameter correction amount and partition parameter compensation amount of each forming control partition in real time to form a real-time closed-loop control across processes.

[0071] In this embodiment, steps S1-S5 are completed collaboratively by the aforementioned process setting module, partition monitoring module, status identification module, cross-process parameter adjustment module, and execution control module. Step S1 corresponds to the process flow and partition setting functions of the process setting module; step S2 corresponds to the data acquisition and partition aggregation functions of the partition monitoring module; step S3 corresponds to the partition status identification and deviation determination functions of the status identification module; step S4 corresponds to the cross-process compensation relationship determination and process parameter calculation functions of the cross-process parameter adjustment module; and step S5 corresponds to the parameter distribution and closed-loop execution functions of the execution control module. Therefore, the system and method of this embodiment can work together to achieve intelligent forming control of large-diameter titanium and titanium alloy pipes.

[0072] Example 2

[0073] like Figure 1 As shown in Example 1, this example further provides a method for setting up forming control zones and determining forming targets for typical large-diameter titanium and titanium alloy pipes, to illustrate the specific application of the zoning strategy of the present invention in actual engineering.

[0074] Specifically, for a large-diameter titanium and titanium alloy tube with an outer diameter of approximately 800 mm, a wall thickness of approximately 40 mm, and a finished length of approximately 6000 mm, considering that the end area is more prone to defects such as excessive ellipticity, uneven wall thickness, and axial bending, this embodiment divides the tube's axial direction into an end compensation zone and a middle stabilization forming zone. The area 1.0-1.5 times the tube diameter from each end is designated as the end compensation zone, and the remaining portion in the middle of the tube is designated as the middle stabilization forming zone. The end compensation zone is mainly used to suppress end tapering, end bulging, and bending defects during the reaming and radial forging processes through enhanced control. The middle stabilization forming zone is mainly used to ensure the uniformity of wall thickness and overall ellipticity control in most areas of the tube body.

[0075] In the circumferential direction, this embodiment divides the pipe circumference into several circumferential zones based on the layout of the forming equipment and the ellipticity and uneven wall thickness distribution characteristics obtained from process simulation or trial production. Specifically, for a process using four-hammer radial forging, it is preferable to divide the circumference into 4 or 8 equally divided circumferential zones, so that each hammer action area and its opposite area correspond to one or more forming control zones, so that differentiated control can be implemented for the defect sensitivity of different hammer action areas during subsequent forming processes.

[0076] By combining the aforementioned axial and circumferential partitions, multiple forming control partitions can be formed, each corresponding to a local area on the pipe with a defined geometric range. For the forming control partitions within the end compensation partitions, in this embodiment, the ellipticity and axial straightness targets are preferably set relatively strictly, limiting smaller allowable ellipticity and axial deflection values. The wall thickness target can be appropriately relaxed while meeting the overall wall thickness requirements, prioritizing the shape accuracy of the end area and subsequent machining allowance. For the forming control partitions within the central stable forming partitions, the wall thickness target is preferably set more strictly to reduce circumferential and axial wall thickness fluctuations. The ellipticity and straightness targets can be slightly wider than those for the end compensation partitions, provided they meet the standard limits, thus ensuring overall forming quality while considering process feasibility and equipment load.

[0077] Furthermore, to accommodate large-diameter titanium and titanium alloy pipes of different specifications, the end compensation partition length, the number of circumferential partitions, and the forming target of each partition in this embodiment are adjusted according to the pipe's outer diameter, wall thickness, length-to-diameter ratio, and final usage conditions. Specifically, for pipes with a large length-to-diameter ratio, the number of axial partitions within the central stabilization forming partition is appropriately increased to improve the control accuracy of straightness and wall thickness fluctuations in long pipe sections; for pipes with thinner walls and sensitivity to ellipticity, the partition resolution is increased in the circumferential direction to more precisely identify and compensate for circumferential ellipticity deviations. Those skilled in the art can make equivalent substitutions or appropriate modifications to the above partitioning strategy according to specific product standards and process conditions.

[0078] Example 3

[0079] like Figure 2 As shown in the figure, this embodiment further provides a method for evaluating the forming quality of a partition, which illustrates how to calculate the geometric dimensional deviation of the forming control partition based on the partition monitoring data, and construct a quality deviation index to characterize the forming quality of each forming control partition.

[0080] In this embodiment, the zone monitoring module acquires and collects the zone outer diameter, zone wall thickness, and axial deflection data of each forming control zone in accordance with the method described in Embodiment 1. Specifically, during the pipe forming process, the outer diameter and wall thickness data of the pipe are collected circumferentially at the exit section of each key process using a laser diameter gauge, forming a ring of discrete measurement points; simultaneously, the deflection distribution curve along the pipe axis is acquired using an axial deflection measuring device or an online measurement system. Based on the axial and circumferential positions of each measuring point, the zone monitoring module assigns the corresponding measurement data to the corresponding forming control zone, forming the zone monitoring data for each forming control zone.

[0081] For the i-th forming control zone, the zone monitoring data includes at least the circumferential outer diameter distribution, circumferential wall thickness distribution, and deflection measurement point data within the axial range of the zone. First, the discrete measurements of the outer diameter and wall thickness within the forming control zone are interpolated and smoothed to obtain the circumferential outer diameter distribution curve and the circumferential wall thickness distribution curve of the zone, thereby reducing the influence of measurement noise. Based on the circumferential outer diameter distribution curve, the ellipticity deviation Ei of the zone can be obtained. Specifically, half the difference between the maximum and minimum circumferential outer diameter values ​​within the forming control zone, or the characteristic value of the deviation from the target circular cross-section, is used as the ellipticity deviation Ei. Based on the circumferential wall thickness distribution curve, the wall thickness deviation Ti of the zone can be obtained. Specifically, the wall thickness deviation index Ti in this embodiment can be determined based on the deviation of the wall thickness at each measurement point relative to the target wall thickness, using methods such as maximum deviation, average deviation, or mean square deviation. This embodiment does not impose any limitations on this.

[0082] Regarding axial straightness, this embodiment evaluates the axial straightness contribution of each forming control zone by analyzing the deflection distribution along the pipe centerline. Specifically, the deflection measurement points measured along the pipe axis are sorted by axial coordinates, and an ideal straight reference is fitted using the least squares method. The deflection deviation of each measurement point relative to the straight reference is then calculated. For the i-th forming control zone, deflection measurement points within the axial range of that zone are selected. The maximum, average, and root mean square values ​​of the deflection deviation within that zone are used as the axial straightness characteristic quantities of that zone. Combined with the overall straightness requirements of the entire pipe, these characteristic quantities are converted into the axial straightness contribution Li of that forming control zone, reflecting the degree of influence of that zone on the overall straightness defects. Through the above processing, the zone ellipticity deviation Ei, zone wall thickness deviation Ti, and zone axial straightness contribution Li of each forming control zone can be obtained. These three together constitute the geometric dimensional deviation of that zone.

[0083] To comprehensively evaluate the forming quality of each forming control zone under a unified scale, this embodiment normalizes the geometric dimensional deviations of different dimensions and introduces a quality deviation index with preset weights. Specifically, the upper limit of the allowable deviation for ellipticity, wall thickness, and straightness is set as follows: Then for the first Each forming control zone can yield the normalized ellipticity deviation. Normalized wall thickness deviation and normalized straightness deviation :

[0084]

[0085] The normalized deviations described above reflect the extent to which each geometric dimensional deviation exceeds its corresponding allowable range; a larger value indicates a more severe deviation. Considering the varying sensitivities of different forming control zones to ellipticity, wall thickness, and straightness, this embodiment pre-weights each type of deviation. This is used to adjust the relative importance of the three types of biases in the overall evaluation, satisfying:

[0086]

[0087] For the Each forming control zone, quality deviation index It can be obtained by the following weighted combination:

[0088]

[0089] Among them, the weighting coefficient Based on the defect sensitivity and design requirements of different forming control zones, settings are determined through process simulation, process experiments, or historical production data statistics. Specifically, for the end compensation zone, a larger ellipticity weight is selected. and straightness weight To emphasize shape accuracy control in the end region; for the central stable forming zone, a larger wall thickness weight is selected. This is to emphasize the control of wall thickness uniformity.

[0090] In this embodiment, the quality deviation index is... As the first The comprehensive evaluation index of forming quality of each forming control zone is the degree of deviation of the zone state parameters from the forming target in the state identification module. When Less than or equal to the preset allowable upper limit When the forming quality of the forming control zone is considered to be within the allowable range; when If a significant forming defect is found in the forming control zone, compensation and adjustment are required through the current and / or subsequent processes. In a later embodiment, the cross-process parameter adjustment module uses the quality deviation index of each forming control zone. As input, the total partition quality compensation amount is further determined, and the compensation amount is allocated between the current process and subsequent processes and converted into specific process parameter adjustment amounts, so as to realize cross-process forming quality compensation and closed-loop control for different forming control partitions.

[0091] Example 4

[0092] like Figure 3 As shown in the figure, this embodiment further provides a cross-process parameter adjustment method based on the forming control zone quality deviation index, which is used to illustrate how the cross-process parameter adjustment module converts the quality deviation index into the total zone quality compensation amount, and performs compensation amount allocation and process parameter conversion between the current process and subsequent processes, thereby realizing cross-process forming quality compensation and closed-loop control for different forming control zones.

[0093] This embodiment uses a process combination of hole expansion—radial forging—straightening as an example. In the process flow, the hole expansion process mainly affects the initial wall thickness distribution of the pipe, the radial forging process has a strong ability to correct ellipticity and wall thickness uniformity, and the straightening process is mainly used to correct axial straightness. For any forming moment, after a certain process is completed, the system calculates the quality deviation index Qi of each forming control zone through the state recognition module according to the method in Embodiment 3, and takes the currently completed process as the current process, and the subsequent unexecuted processes as the subsequent processes.

[0094] 1. Conversion of Quality Deviation Index to Total Regional Quality Compensation

[0095] For the There are several forming control zones, with a quality deviation index of [missing value]. The maximum allowed is when If the forming quality of the zone does not exceed the allowable upper limit, it is considered to be within an acceptable range and no compensation is required; when If the allowable upper limit is exceeded, the partition is considered to have a significant forming defect, requiring compensation through the current process and / or subsequent processes. In this embodiment, the total partition quality compensation amount for the forming control partition is... Defined as:

[0096]

[0097] in, The quality deviation index increases monotonically as it exceeds the allowable upper limit; a larger value indicates that the forming control zone requires a higher amount of compensation in subsequent forming processes. In other embodiments, a nonlinear function or lookup table method can also be used to... Mapped to .

[0098] 2. Cross-process compensation relationship and quality compensation allocation coefficient

[0099] To make reasonable use of the correction capabilities of each process, this embodiment allocates the total regional quality compensation amount between the current process and subsequent processes through cross-process compensation relationships. Specifically, the correction capabilities of the hole expansion process, each radial forging process, and the straightening process for ellipticity deviation, wall thickness deviation, and straightness deviation can be analyzed through finite element process simulation and small-batch trial production tests. In addition, the available adjustment range of the forming equipment for each process is combined to determine the proportion that each process can bear in the compensation task.

[0100] For the i-th forming control zone, in this embodiment, quality compensation allocation coefficients are set for the current process and each subsequent process, such that all coefficients are non-negative, and the sum of the allocation coefficients for each process in the same zone is 1. Processes with greater correction capability and larger adjustable margin are allocated higher quality compensation ratios. Specifically, for zones that mainly correct ellipticity and wall thickness, the allocation coefficient for the radial forging process is increased; for zones that mainly correct straightness, the allocation coefficient for the straightening process is increased.

[0101] After determining the allocation coefficients, the total partition quality compensation amount will be... The quality compensation amount is allocated to the current process and each subsequent process to obtain the corresponding quality compensation amount for each process. and Specifically, for the current process, it is represented as:

[0102]

[0103] For each subsequent process, it is as follows:

[0104]

[0105] in, For the first The quality compensation allocation coefficient for each forming control zone in the current process. This is the quality compensation allocation coefficient for the i-th forming control zone in the subsequent k-th process.

[0106] 3. Conversion between quality compensation amount and process parameter correction amount and process parameter compensation amount

[0107] After obtaining the quality compensation amount for each process, it needs to be converted into the corresponding process parameter correction amount and the corresponding process parameter compensation amount for each zone, so that the execution control module can adjust the forming process parameters of each forming control zone accordingly. In this embodiment, for the hole expansion and radial forging processes, compensation can be achieved by adjusting the radial reduction rate and feed rate of each forming control zone; for the heating process, the temperature distribution can be changed by adjusting the heating power and holding time of each zone; for the straightening process, the straightness can be corrected by adjusting the straightening torque and straightening roll gap of each zone.

[0108] Specifically, for the mass compensation amount of a certain forming control zone in the current radial forging process, the correspondence between the mass compensation amount and the radial reduction rate correction amount and the feed rate correction amount can be established in advance through process experiments or simulation analysis. This ensures that the larger the mass compensation amount, the greater the adjustment range of the corresponding reduction rate and feed rate. For the mass compensation amount in the straightening process, the correspondence between the mass compensation amount and the straightening torque compensation amount and the straightening roll gap compensation amount is established. The above correspondence is implemented using linear proportional, piecewise linear, or lookup table forms.

[0109] Through the above conversion, the correction amount of the partition parameters for the i-th forming control partition in the current process, and the compensation amount of the partition parameters in each subsequent process can be obtained. The execution control module can apply the correction amount of the partition parameters in the subsequent loading passes of the current process, and apply the compensation amount of the partition parameters in the initial loading pass or corresponding control cycle of the corresponding subsequent process, thereby realizing pass-level closed-loop control within the same process and cross-process compensation between different processes.

[0110] In summary, this embodiment introduces the total partition quality compensation amount, the quality compensation allocation coefficient, and the mapping relationship between the quality compensation amount and the process parameter adjustment amount. This enables cross-process parameter adaptive adjustment driven by the quality deviation index of each forming control partition, allowing the current process and subsequent processes to work together to suppress the accumulation of ellipticity, wall thickness unevenness, and axial straightness deviations in the process chain, thereby improving the consistency and stability of the forming quality of large-diameter titanium and titanium alloy pipes.

[0111] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A large-diameter intelligent forming system for titanium and titanium alloy pipes, characterized in that, include: The process setting module includes a process generation unit and a partition setting unit. The process generation unit is used to set a process flow covering at least two forming processes among extrusion, reaming, radial forging, heat treatment and straightening, according to the design requirements of large-diameter titanium and titanium alloy tubes. The partition setting unit divides the large-diameter titanium and titanium alloy tubes to be formed into several forming control partitions along the axial and circumferential directions according to the geometric dimensions and forming accuracy requirements of the large-diameter titanium and titanium alloy tubes, and sets partition forming targets for each forming control partition. The partition monitoring module is used to perform online monitoring of the large-diameter titanium and titanium alloy pipes located in each forming control partition during the process flow, and to collect process parameters of each forming control partition. The partition monitoring module performs partitioned collection of the process parameters according to the forming control partition to form partition monitoring data. The status recognition module is used to calculate the partition status parameters of each forming control partition based on the partition monitoring data and the partition forming target. The partition status parameters include at least the geometric dimension deviation of each forming control partition. The status recognition module calculates the degree of deviation between the partition status parameters and the partition forming target based on the partition status parameters, and determines whether each partition status parameter is within a preset allowable range based on the degree of deviation. The cross-process parameter adjustment module is used to determine the cross-process compensation relationship between the current process and at least one subsequent process in the process flow according to the degree of deviation when at least one partition status parameter exceeds the preset allowable range, and to calculate the partition parameter correction amount of the forming control partition in the current process and the partition parameter compensation amount in each subsequent process based on the cross-process compensation relationship. The execution control module is used to send the partition parameter correction amount and the partition parameter compensation amount to the forming equipment of the corresponding process, control the forming equipment to perform differentiated forming control on each forming control partition according to the process flow, continuously acquire updated partition monitoring data during the forming process and feed it back to the status recognition module, and adjust the partition parameter correction amount and partition parameter compensation amount of each forming control partition in real time based on the updated partition monitoring data, forming a real-time closed-loop control across processes.

2. The intelligent forming system for large-diameter titanium and titanium alloy pipes according to claim 1, characterized in that: The partition setting unit divides the large-diameter titanium and titanium alloy pipe into an end compensation partition and a middle stable forming partition along the axial direction based on the geometric dimension distribution of the large-diameter titanium and titanium alloy pipe in the axial and circumferential directions. Based on the distribution characteristics of ellipticity and uneven wall thickness, the end compensation partition and the middle stable forming partition are further divided circumferentially to form the forming control partition. The forming target of the partition includes the wall thickness target, the ellipticity target, and the straightness target.

3. The intelligent forming system for large-diameter titanium and titanium alloy pipes according to claim 1, characterized in that: The zone monitoring module includes an infrared temperature sensor, a forming load sensor, a displacement sensor, and a laser diameter gauge, used to acquire the process parameters through online monitoring. The process parameters include zone temperature, zone forming load, zone displacement, and zone geometry.

4. The intelligent forming system for large-diameter titanium and titanium alloy pipes according to claim 1, characterized in that: The zone monitoring data includes the zone outer diameter, zone wall thickness, and axial deflection. The calculation of the geometric dimension deviation includes the following steps: S41. Interpolate and smooth the outer diameter and wall thickness of the partition to obtain the circumferential outer diameter distribution and circumferential wall thickness distribution; S42. The ellipticity deviation of each forming control zone is calculated based on the circumferential outer diameter distribution, and the wall thickness deviation of each forming control zone is calculated based on the circumferential wall thickness distribution. S43. The partition ellipticity deviation, the partition wall thickness deviation, and the partition axial straightness contribution calculated from the axial deflection are taken as the geometric dimension deviation.

5. The intelligent forming system for large-diameter titanium and titanium alloy pipes according to claim 4, characterized in that: The state recognition module includes a partitioned forming quality assessment unit. The partitioned forming quality assessment unit is used to normalize the partitioned ellipticity deviation, partitioned wall thickness deviation, and partitioned axial straightness contribution of each forming control partition to form a normalized deviation value. The normalized deviation value is then weighted and combined according to a preset weight to obtain the quality deviation index of each forming control partition. The degree of deviation is the quality deviation index of each forming control partition.

6. The intelligent forming system for large-diameter titanium and titanium alloy pipes according to claim 5, characterized in that: The calculation of the partition parameter correction amount and the partition parameter compensation amount includes the following steps: S61. When the quality deviation index of the forming control zone exceeds a preset upper limit, the total partition quality compensation amount of the forming control zone is obtained based on the quality deviation index. S62. Based on the cross-process compensation relationship, determine the quality compensation allocation coefficients corresponding to the current process and each subsequent process. The cross-process compensation relationship is predetermined based on the correction capability of each forming process for the geometric deviation and the available adjustment range of the corresponding forming equipment. S63. Based on the total partition quality compensation amount and the quality compensation allocation coefficient, convert the total partition quality compensation amount into the partition parameter correction amount of the forming control partition in the current process, and the partition parameter compensation amount in each subsequent process.

7. The intelligent forming system for large-diameter titanium and titanium alloy pipes according to claim 1, characterized in that: The partition parameter correction amount and partition parameter compensation amount include at least one or more of radial reduction rate, feed rate, heating power and straightening torque, and the forming equipment includes at least one of extrusion press, radial forging machine, heating device and straightening device.

8. The intelligent forming system for large-diameter titanium and titanium alloy pipes according to claim 1, characterized in that: At least one step in the process flow includes multiple loading passes, the partition parameter correction amount takes effect in the subsequent loading passes corresponding to the current step, and the partition parameter compensation amount takes effect in the initial loading pass corresponding to the subsequent step.

9. A method for intelligent forming of large-diameter titanium and titanium alloy pipes, characterized in that, include: S1. Based on the design requirements of large-diameter titanium and titanium alloy tubes, a process flow covering at least two forming processes among extrusion, reaming, radial forging, heat treatment and straightening is set. Based on the axial and circumferential geometric dimensions and forming accuracy requirements of the large-diameter titanium and titanium alloy tubes, the large-diameter titanium and titanium alloy tubes to be formed are divided into several forming control zones along the axial and circumferential directions, and forming targets are set for each forming control zone. S2. In each forming step of the process flow, the large-diameter titanium and titanium alloy pipes located in each forming control zone are monitored online, the process parameters of each forming control zone are collected, and the process parameters are collected by zone according to the forming control zone to form zone monitoring data. S3. Based on the partition monitoring data and the partition forming target, calculate the partition status parameters of each forming control partition. The partition status parameters include at least the geometric dimension deviation of each forming control partition. Determine the degree of deviation of each forming control partition based on the partition status parameters. Determine whether the partition status parameters are within the preset allowable range based on the degree of deviation. S4. When it is determined that at least one partition status parameter exceeds the preset allowable range, the cross-process compensation relationship between the current process and at least one subsequent process in the process flow is determined according to the degree of deviation, and the partition parameter correction amount of the forming control partition in the current process and the partition parameter compensation amount in each subsequent process are calculated based on the cross-process compensation relationship. S5. The partition parameter correction amount and the partition parameter compensation amount are sent to the forming equipment of the corresponding process, and the forming equipment is controlled to implement differentiated forming control for each forming control partition according to the process flow. During the forming process, the updated partition monitoring data is continuously acquired and S3 and S4 are repeatedly executed. Based on the updated partition monitoring data, the partition parameter correction amount and partition parameter compensation amount of each forming control partition are adjusted in real time to form a real-time closed-loop control across processes.

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