Method and system for cooperatively eliminating welding residual stress of welded component

Abstract

The invention belongs to the technical field of welding residual stress elimination. According to the collaborative elimination method and system for the welding residual stress of the welded component, frequency spectrum harmonic vibration aging treatment is conducted on the welded component so that the residual stress of the welded component in the first stage can be eliminated; after the residual stress in the first stage is eliminated, the residual stress distribution state of the welding component after the initial residual stress is eliminated is obtained, and a to-be-eliminated area with the welding tensile stress larger than a first set threshold value and the working load larger than a second set threshold value is selected according to the residual stress distribution state; and local weld joint ultrasonic impact treatment is conducted on the to-be-eliminated areas, so that second-stage residual stress elimination is conducted on the welded component till the residual stress of all the to-be-eliminated areas is eliminated. According to the method, the problem of poor effect of a single residual stress eliminating scheme is solved, the peak value of the welding residual stress of the welding component is greatly reduced and is more uniform, and then the dimensional precision of the welding component is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of welding residual stress elimination technology, and in particular to a method and system for synergistic elimination of welding residual stress in welded components. Background Technology

[0002] The rapid heating and cooling during the welding process inevitably leads to uneven and uncoordinated plastic deformation of the weld and the surrounding base material, ultimately resulting in uneven residual stress. The bogie is the running gear of a railcar, and its performance directly affects the stability, safety, and reliability of railcar operation. As a typical welded component, the presence of residual stress not only reduces the dimensional accuracy of the bogie frame but also shortens its service life, and in severe cases, even causes it to fail and be scrapped, seriously affecting the operational reliability and service safety of the bogie frame.

[0003] Currently, in the rail vehicle manufacturing industry, thermal aging is the commonly used method for eliminating residual stress in bogie frames. While this method can release welding residual stress and significantly reduce residual stress, the improvement in the uniformity of residual stress is not significant. In particular, during the thermal aging process, the heating rate, cooling rate, holding temperature, and holding time all need to be strictly controlled, and the entire thermal aging process typically takes more than ten hours. This method faces many limitations, including long processing time, high energy consumption, high carbon emissions, and high costs. It cannot meet the national strategic plan for carbon peaking and carbon neutrality, nor is it suitable for enterprises' production requirements for energy conservation, emission reduction, green environmental protection, cost reduction, and efficiency improvement. At the same time, in order to improve the efficiency of thermal aging, multiple bogie frames are generally put into the heat treatment furnace at the same time. Their different placement positions in the furnace can lead to uneven stress elimination effects, especially the problem of individual dimensional accuracy not meeting requirements. This often results in the need for bogie frame straightening treatment after thermal aging, increasing the workload.

[0004] To address the shortcomings of thermal aging treatment, researchers have proposed a method of eliminating crankshaft internal stress through spectral harmonic vibration aging treatment. However, current spectral harmonic vibration aging treatment methods can only achieve overall elimination of welding stress in the bogie frame, and cannot perform timely targeted elimination of stress in certain specific weld stress concentration areas, resulting in poor stress elimination effect. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method and system for the coordinated elimination of welding residual stress in welded components. First, overall spectrum harmonic vibration aging treatment is used to eliminate and homogenize the welding residual stress in the welded components. Then, local ultrasonic impact treatment is used to further eliminate and homogenize the residual stress around the key welds, resulting in a significant reduction and greater uniformity of the peak value of welding residual stress in the welded components, thereby ensuring the dimensional accuracy of the welded components.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a method for synergistic elimination of welding residual stress in welded components.

[0007] A method for synergistic elimination of residual welding stress in welded components includes the following steps: The welded components are subjected to spectrum harmonic vibration aging treatment (i.e., a process method that uses mechanical vibration to induce microscopic plastic deformation inside the metal material, thereby reducing and homogenizing residual stress and stabilizing the dimensional accuracy of the workpiece) to eliminate residual stress in the first stage of the welded components. After the first stage of residual stress elimination is completed, the residual stress distribution state of the welded component after the initial residual stress elimination is obtained. Based on the residual stress distribution state, the area to be eliminated where the welding tensile stress is greater than the first set threshold and the working load is greater than the second set threshold is selected. The area to be eliminated is subjected to local ultrasonic impact treatment of the weld seam to eliminate residual stress in the welded component in the second stage, until all residual stress in the area to be eliminated is eliminated.

[0008] In one implementation of the first aspect of the present invention, the welding component is subjected to spectral harmonic vibration aging treatment, including: Spectral analysis was performed to obtain the optimal multiple resonant frequencies of the welded component and sort them. Vibration aging was performed in sequence according to the resonant frequencies, and the vibration aging curves at each frequency were recorded. After the vibration aging at each frequency was completed, the frequency sweep curve after vibration aging was recorded. The effectiveness of vibration aging is determined based on the vibration aging curves and the frequency sweep curve after vibration aging. If effective, the residual stress elimination in the first stage is completed. If ineffective, the residual stress elimination process in the first stage is repeated until the vibration aging is effective.

[0009] In one implementation of the first aspect of the present invention, local ultrasonic impact treatment of the weld seam in the area to be eliminated includes: The impact range from the weld toe to the base material is within the set range, and the impact ranges on both sides of the weld are the same or the difference in impact ranges is within the set range.

[0010] Secondly, the present invention provides a system for synergistic elimination of residual stress in welded components.

[0011] A collaborative system for eliminating residual stress in welded components includes a spectrum harmonic vibration aging treatment subsystem, a stress testing unit, and an ultrasonic impact treatment subsystem. A spectrum harmonic vibration aging treatment subsystem is used to perform spectrum harmonic vibration aging treatment on welded components in order to eliminate residual stress in the first stage of the welded components. The stress testing unit acquires the residual stress distribution of the welded component after preliminary residual stress elimination. Based on the residual stress distribution, it selects the area to be eliminated where the welding tensile stress is greater than the first set threshold and the working load is greater than the second set threshold. The ultrasonic impact treatment subsystem performs local ultrasonic impact treatment on the weld seam in the area to be eliminated, so as to eliminate residual stress in the second stage of the welded component.

[0012] In one implementation of the second aspect of the present invention, the spectrum harmonic vibration aging treatment subsystem is communicatively connected to the stress testing unit, and the stress testing unit is communicatively connected to the ultrasonic impact treatment subsystem. After the spectrum harmonic vibration aging treatment subsystem completes the first stage of residual stress elimination, it sends a completion notification to the stress testing unit. The stress testing unit then initiates stress detection and sends the detected area to be eliminated to the ultrasonic impact treatment subsystem for the second stage of residual stress elimination.

[0013] In one implementation of the second aspect of the present invention, an ultrasonic impact treatment subsystem includes: an impact head, an amplitude transformer, a transducer, and an ultrasonic impact control module. The ultrasonic impact control module is communicatively connected to the transducer. The transducer is connected to the impact head through the amplitude transformer. Ultrasonic energy is transmitted to the impact head through the transducer and the amplitude transformer, and the impact head is used to eliminate residual stress in the second stage of the weld.

[0014] As a further limitation of the second aspect of the present invention, after the second stage of residual stress elimination is completed, the stress testing unit evaluates the area to be eliminated again, and continues to perform the second stage of residual stress elimination processing on the remaining areas to be eliminated until there are no new areas to be eliminated.

[0015] In one implementation of the second aspect of the present invention, the spectrum harmonic vibration aging treatment subsystem includes: a rubber pad, a vibrator, a sensor, and a spectrum harmonic vibration aging control module, wherein the spectrum harmonic vibration aging control module is communicatively connected to the vibrator and the sensor respectively. The welding components are arranged on rubber pads, and the exciter and sensor are detachably connected to the welding components. The spectrum harmonic vibration aging control module automatically performs spectrum analysis to obtain the optimal multiple resonant frequencies of the welding components and sorts them. Vibration aging is performed sequentially according to the resonant frequencies, and the vibration aging curves at each frequency are recorded. After the vibration aging at each frequency is completed, the frequency sweep curve after vibration aging is recorded. The effectiveness of vibration aging is determined based on the vibration aging curves and the frequency sweep curve after vibration aging. If it is effective, the residual stress elimination in the first stage is completed. If it is ineffective, the residual stress elimination process in the first stage is repeated until the vibration aging is effective.

[0016] As a further limitation of the second aspect of the invention, at least two sensors are fixed to the edge of the welded component by magnetic attraction, and the vibrator is fixed to the welded component by bolts.

[0017] The beneficial effects of the present invention are as follows: This invention achieves a precise progression from global homogenization to local strengthening of residual stress control by organically integrating spectral harmonic vibration aging and ultrasonic impact treatment. The former utilizes multi-frequency vibration energy to homogenize and attenuate the overall residual stress field of the structure, effectively suppressing the risk of macroscopic deformation. The latter, based on a stress-load dual-factor evaluation model, accurately locates high-risk areas and induces a gradient compressive stress layer on the material surface through high-frequency impact, forming a dynamic balance mechanism with the tensile stress of the matrix, significantly weakening the stress concentration effect under service conditions. The synergistic effect of the two-stage treatment not only ensures the stability of the overall mechanical performance of the structure but also breaks through the fatigue strength bottleneck of key parts, providing an efficient and controllable residual stress regulation solution for high reliability and long service life of rail transit equipment.

[0018] This invention significantly improves the reliability and efficiency of residual stress elimination in welded components through refined implementation of spectral harmonic vibration aging treatment. First, based on spectral analysis, it accurately identifies and sorts the multi-order resonant frequencies of the framework, enabling vibration energy to act on structural regions with different geometric characteristics in stages and frequency bands, effectively avoiding vibration blind spots that may be caused by single-frequency excitation. Second, by recording the vibration aging curves at each frequency and the post-treatment frequency sweep curves, a complete dynamic monitoring system for stress release is constructed, which can quantitatively evaluate the effect of each vibration treatment and ensure sufficient attenuation of the residual stress field. Finally, a closed-loop control mechanism of "treatment-evaluation-feedback" is adopted. When vibration aging is detected to be ineffective, a reprocessing process is automatically triggered until the stress elimination standard is reached. This adaptive adjustment strategy ensures the stability of the treatment quality and avoids the risk of material damage caused by excessive vibration, providing a reliable stress reference state for subsequent local ultrasonic impact treatment.

[0019] This invention achieves fully automated and coordinated control of the residual stress elimination process by constructing a closed-loop communication mechanism for three subsystems: spectral harmonic vibration aging, stress testing, and ultrasonic impact treatment. After the spectral harmonic vibration aging treatment subsystem completes the initial elimination of residual stress in the welded component, it automatically triggers the stress testing unit to start a full-field stress scan, ensuring precise synchronization between the testing timing and the treatment status. Based on measured data, the stress testing unit intelligently identifies high-stress-high-load coupling areas and transmits the coordinates and stress parameters of the area to be eliminated to the ultrasonic impact treatment subsystem without loss, avoiding positioning errors that may be caused by manual intervention. After receiving precise operation instructions, the ultrasonic impact treatment subsystem performs directional stress elimination on the target area, forming a three-level progressive treatment chain of "global homogenization - precise positioning - local strengthening". This fully digitalized management and control mode significantly improves processing efficiency and reliability, ensuring the repeatability and consistency of the residual stress elimination effect in the welded component.

[0020] This invention achieves in-depth optimization and quality control of residual stress elimination through a stress retesting and closed-loop iterative processing mechanism after the second stage. After local ultrasonic impact treatment, the stress testing unit performs a secondary scan and evaluation of the original high-stress area, using high-precision strain measurement technology to capture minute residual stress, ensuring that the test results truly reflect the treatment effect. For areas that still exceed the threshold during retesting, the system automatically triggers a new round of ultrasonic impact treatment, forming a closed-loop control cycle of "treatment-detection-feedback-reprocessing". This iterative mechanism not only solves the problem of stress elimination blind spots that may exist in a single treatment round, but also gradually optimizes the stress field distribution on the material surface through multi-round energy superposition, ultimately achieving full compliance of residual stress in the area to be eliminated. Compared with the traditional open-loop treatment method, this scheme significantly improves the thoroughness of stress elimination in key parts, providing dual protection for the fatigue resistance of welded components under long-term dynamic loads. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0022] Figure 1 A schematic diagram of a collaborative system for eliminating residual welding stress in welded components, provided as an exemplary embodiment of the present invention; Figure 2 A schematic diagram of a method for synergistic elimination of residual welding stress in welded components, provided as an exemplary embodiment of the present invention; Figure 3 A schematic diagram of the aging curve of a first frequency provided for an exemplary embodiment of the present invention; Figure 4A schematic diagram of the aging curve of a second frequency provided as an exemplary embodiment of the present invention; Figure 5 A schematic diagram of the aging curve of a third frequency provided as an exemplary embodiment of the present invention; Figure 6 A schematic diagram of the time-efficiency curve for a fourth frequency provided as an exemplary embodiment of the present invention; Figure 7 A schematic diagram of the time-efficiency curve for the fifth frequency provided as an exemplary embodiment of the present invention; Figure 8 A schematic diagram of the aging curve for the sixth frequency provided as an exemplary embodiment of the present invention; Figure 9 A schematic diagram of the time-efficiency curve for the seventh frequency provided as an exemplary embodiment of the present invention; Figure 10 A schematic diagram of a sweep frequency curve provided for an exemplary embodiment of the present invention.

[0023] The components include: 1. Bogie frame; 2. Rubber pad; 3. Vibrator; 4. Bow-shaped clamp; 5. Fastening bolt; 6. Sensor; 7. Spectrum harmonic vibration aging control module; 8. Local weld; 9. Impact head; 10. Amplitude rod; 11. Transducer; and 12. Ultrasonic impact control module. Detailed Implementation

[0024] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0025] This implementation proposes a collaborative system for eliminating residual stress in welded components, such as... Figure 1 As shown, the method for bogie frame of rail train (i.e., for bogie frame, a typical welded component; of course, the method of this invention is also applicable to other large welded components in other industrial fields, which will not be elaborated here) includes: rubber pad 2, vibrator 3, bow-shaped clamp 4, fastening bolt 5, sensor 6, spectrum harmonic vibration aging control module 7, impact head 9, amplitude transformer 10, transducer 11, and ultrasonic impact control module 12; by synergistically employing the stress relief treatment method of overall frame spectrum harmonic vibration aging and local weld ultrasonic impact, the residual stress of the bogie frame welding is effectively eliminated and homogenized, solving the problem of low stress elimination rate and homogenization rate of traditional thermal aging stress relief treatment method for bogie frame. This invention replaces thermal aging, which can not only improve the stress relief effect and ensure dimensional accuracy, but also improve production efficiency, reduce processing costs, and achieve energy conservation and emission reduction.

[0026] The stress relief treatment of the steering frame of this invention is implemented in two stages: the first stage is the overall frame spectrum vibration aging treatment, which utilizes the spectrum harmonic vibration aging treatment subsystem, which includes the spectrum harmonic vibration aging control module 7, the vibrator 3, the bow-shaped clamp 4, the sensor 6, and the rubber pad 2; the second stage is the local weld impact treatment, which utilizes the ultrasonic impact subsystem, which includes the impact head 9, the amplitude transformer 10, the transducer 11, and the ultrasonic impact control module 12.

[0027] Figure 2 A method for collaboratively eliminating welding residual stress in a bogie frame 1 is shown, comprising the following steps: S201: Perform spectral harmonic vibration aging treatment on bogie frame 1 to eliminate residual stress in the first stage of bogie frame 1; S203: After the residual stress in the first stage is eliminated, the residual stress distribution state of the bogie frame 1 after the initial residual stress elimination is obtained. Based on the residual stress distribution state, the area to be eliminated where the welding tensile stress is greater than the first set threshold and the working load is greater than the second set threshold is selected. S203: Perform localized ultrasonic impact treatment on the weld seam 8 in the area to be eliminated, so as to carry out the second stage of residual stress elimination on the bogie frame 1, until all residual stress in the area to be eliminated is eliminated.

[0028] More specifically, the implementation method of the overall frame spectrum harmonic vibration aging treatment is as follows: 1) Place the bogie frame 1 stably on two rubber pads 2; 2) Place the exciter 3 in a suitable vibration position and rigidly fix it with bow-shaped clamps 5 and fastening bolts 5, and set a suitable exciter 3; 3) Attach two sensors 6 to the edge of the bogie frame 1; 4) Connect the exciter 3 and sensors 6 to the control system respectively; 5) Start the spectrum harmonic vibration aging control module 7, which automatically performs spectrum analysis to obtain the resonant frequency distribution and sorting; 6) According to the obtained resonant frequency distribution and sorting, perform spectrum harmonic vibration aging treatment on the bogie frame 1 in sequence; 7) Determine whether the vibration aging is effective based on the vibration aging curves of each frequency and the frequency sweep curve after vibration aging output by the system; if effective, perform stress detection; if ineffective, continue to repeat the residual stress elimination process of the first stage until the vibration aging is effective.

[0029] After the first stage of overall frame spectrum harmonic vibration aging treatment, residual stress test is carried out on bogie frame 1. Based on the residual stress distribution, the high tensile stress area of ​​the weld and the part with large working load are selected for the second stage of local weld 8 ultrasonic impact treatment (that is, the location of the second stage ultrasonic impact treatment is determined by the stress relief result of the first stage vibration aging) to further reduce and homogenize the welding residual stress.

[0030] The implementation method of ultrasonic impact treatment for local weld 8 is as follows: 1) Based on the structural characteristics and stress state analysis of the bogie frame 1, select the key weld; 2) Set the ultrasonic impact treatment parameters through the ultrasonic impact control module 12 and start the ultrasonic impact equipment; 3) Align the impact head 9 with the weld toe position, the impact range from the weld toe to the base material has an appropriate width, the impact range on both sides of the weld should be as consistent as possible, and the moving speed of the impact head 9 should be kept as uniform and stable as possible.

[0031] It should be noted that the above scheme is a manually implemented scheme. That is, after the first stage of overall frame spectrum harmonic vibration aging treatment, stress detection and identification need to be carried out manually, and then the second stage of local weld 8 ultrasonic impact treatment is carried out based on the identification results.

[0032] To achieve automated processing, a stress testing unit was introduced. A spectrum harmonic vibration aging treatment subsystem was used to perform spectrum harmonic vibration aging treatment on the bogie frame 1 to eliminate residual stress in the first stage. The stress testing unit obtained the residual stress distribution state of the bogie frame 1 after the initial residual stress elimination. Based on the stress distribution state, the area to be eliminated was selected where the welding tensile stress was greater than a first set threshold and the working load was greater than a second set threshold. The ultrasonic impact treatment subsystem performed local weld 8 ultrasonic impact treatment on the area to be eliminated to eliminate residual stress in the second stage of residual stress elimination on the bogie frame 1.

[0033] More specifically, the spectral harmonic vibration aging treatment subsystem is communicatively connected to the stress testing unit, and the stress testing unit is communicatively connected to the ultrasonic shock treatment subsystem. After the spectral harmonic vibration aging treatment subsystem completes the first stage of residual stress elimination, it sends a completion notification to the stress testing unit. The stress testing unit then initiates stress detection and sends the detected areas to be eliminated to the ultrasonic shock treatment subsystem for the second stage of residual stress elimination. After the second stage of residual stress elimination is completed, the stress testing unit re-evaluates the areas to be eliminated and continues the second stage of residual stress elimination treatment for any remaining areas until no new areas to be eliminated exist.

[0034] More specifically, the present invention provides the following specific examples: 1) The bogie frame 1 is stably placed on two rubber pads 2; 2) The vibrator 3 is placed at a reasonable position on the bogie frame 1, and the vibrator 3 is rigidly fixed to the bogie frame 1 with fixing bolts 5 using a specially designed bow-shaped clamp 4, and the excitation force is set to 30% of the maximum excitation force; 3) Two sensors 6 are fixed to the edge of the bogie frame 1 by magnetic attraction; 4) The data transmission lines of the vibrator 3 and the sensors 6 are connected to the spectrum harmonic vibration aging control module 7; 5) The spectrum harmonic vibration aging control module 7 is started, and the system will automatically analyze the spectrum to obtain the seven preferred resonant frequencies and sort them; 6) The spectrum harmonic vibration aging control module 7 performs vibration aging in sequence according to the seven resonant frequencies, records the vibration aging curve at each frequency, and records the sweep frequency curve after vibration aging is completed for the seven frequencies; 7) According to The vibration aging curve and the post-vibration aging sweep curve are used to determine whether the vibration aging is effective. If the evaluation criteria of the "Vibration Aging Effect Evaluation Method" are met, that is, the spectral harmonic vibration aging has achieved the desired effect, the overall frame spectral harmonic vibration aging treatment takes a total of 42.5 minutes; 8) After the spectral vibration aging is completed, the key welds are selected based on the structural characteristics and stress state analysis of the bogie frame 1; 9) The ultrasonic impact treatment parameters are set through the ultrasonic impact control module 12: the ultrasonic impact frequency is 20kHz and the ultrasonic impact current is 0.8A; 10) The ultrasonic impact equipment is started, and the ultrasonic energy is transmitted to the impact head 9 through the transducer 11 and the amplitude transformer 10. The impact head 9 is aligned with the weld toe position, and the impact range is about 10mm wide from the weld toe to the base material. The impact range on both sides of the weld is as consistent as possible. The moving speed of the impact head 9 is controlled at 30~50m / h and kept as uniform and stable as possible. The ultrasonic impact treatment of the local weld 8 takes about 50 minutes.

[0035] In this implementation, for the bogie frame 1, the resonant frequencies and their order obtained by the spectrum harmonic vibration aging control module 7 through automatic spectrum analysis, the corresponding exciter 3 rotation speed and vibration aging time are shown in Table 1, and the aging curves of the vibration aging output at each frequency are shown in Table 1. Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown.

[0036] Table 1: Preferred frequencies and order of frequency for aging of spectrum harmonic vibration, speed of exciter 3 and excitation time.

[0037]

[0038] The aging results of the spectral harmonic vibration show that the total aging time for the entire spectral harmonic vibration is 42.5 min, and the aging curve ( at (curve) and the sweep frequency curve after vibration aging is completed ( an The curve meets the requirements for eliminating residual stress as specified in the evaluation criteria of the "Method for Evaluating the Effect of Vibration Aging".

[0039] Table 2 shows a comparison of the equivalent residual stress at six key locations before and after the overall frame spectral harmonic vibration aging and ultrasonic impact stress relief treatment of local weld seams 8. Calculations show that the equivalent residual stress elimination rate after treatment is approximately 75.1%, and the equivalent residual stress homogenization rate is approximately 88.4%. The dimensional accuracy of all 120 points on the bogie frame components meets the design requirements and requires no adjustment or correction.

[0040] Table 2: Comparison of equivalent residual stress at various points before and after the stress relief treatment of bogie frame 1 (MPa).

[0041]

[0042] Table 3 shows a comparison of the process cycle, energy consumption cost, and carbon emissions between the traditional thermal aging treatment and the synergistic treatment method of this invention for a single steering frame 1. The comparison results show that the processing cycle of the method of this invention is shortened by about 91.1%, energy consumption and carbon emissions are reduced by about 99.3%, and dimensional accuracy meets 100% of the requirements, thus achieving the goals of improving production efficiency, reducing processing costs, and achieving energy conservation and emission reduction.

[0043] Table 3: Comparison of traditional thermal aging and the method of the present invention for a single bogie frame 1 in terms of process cycle, energy consumption cost and carbon emissions.

[0044]

[0045] In summary, this invention employs a synergistic stress relief method combining overall frame harmonic vibration aging and localized ultrasonic impact treatment of weld seams 8. First, overall harmonic vibration aging eliminates and homogenizes the welding residual stress of the bogie frame 1. Then, localized ultrasonic impact treatment further eliminates and homogenizes the residual stress around key weld seams, resulting in a significant reduction and greater uniformity of the peak value of welding residual stress in the bogie frame 1, thereby ensuring the dimensional accuracy of the product. Compared to the current thermal aging treatment, which achieves a residual stress elimination rate of 45.8%, a residual stress homogenization rate of 35.2%, and requires subsequent adjustments and corrections for some dimensional accuracy discrepancies, this invention achieves a residual stress elimination rate of 75.1% and a residual stress homogenization rate of 88.4%, representing a significant improvement in both rates, with 100% dimensional accuracy met. Furthermore, compared to traditional thermal aging treatment, this invention shortens the processing cycle by approximately 91.1%, reduces energy consumption and carbon emissions by approximately 99.3%, and achieves 100% dimensional accuracy met, thus improving production efficiency, reducing processing costs, and realizing energy conservation and emission reduction.

[0046] Alternatively, in some other implementations, the selection of resonant frequencies during the overall frame spectral vibration aging treatment stage in the traditional process of stress relief treatment of the frame has significant technical defects. Traditional solutions only obtain resonant frequencies through spectral analysis and perform simple sorting, without considering the differences in residual stress distribution in different areas of the frame, resulting in a lack of specificity in the frequency selection process. Specifically: first, high residual stress areas may not be matched with the optimal resonant frequency, leading to ineffective transmission of vibration energy to stress concentration areas and poor stress relief; second, low stress areas may experience new stress concentration due to excessive vibration, which in turn affects the structural stability of the frame; third, the fixed frequency sorting mode is difficult to adapt to manufacturing errors in different batches of frames (such as stress distribution differences caused by welding process fluctuations), resulting in poor versatility. From a technical perspective, this problem stems from the decoupling of the vibration aging system from the stress state of the components. Traditional spectral analysis only focuses on the inherent frequency characteristics of the structure, ignoring the dynamic response relationship between "frequency and stress." For example, when a welded joint in the structure experiences tensile stress exceeding 200 MPa, if the selected resonant frequency does not match the vibration modes of that region, the vibration energy will be rapidly dissipated by the structural damping, failing to induce plastic deformation in that region to release the stress. Furthermore, the standard "Methods for Evaluating the Effect of Vibration Aging" only specifies the evaluation indicators for vibration aging, without addressing a quantitative method for frequency selection. This leads to reliance on experience in frequency selection during actual operation, resulting in poor consistency. Production data from a rail transit equipment company shows that using traditional methods, approximately 30% of the structures still exhibit localized residual stress exceeding the standard (greater than 150 MPa) after vibration aging, requiring secondary treatment and severely impacting production efficiency.

[0047] In view of the above problems, alternatively, in some other implementations, the optimal resonant frequency for residual stress elimination in the first stage is proposed as: (1); in, The optimal resonant frequency (Hz); This is the stress sensitivity coefficient (values ​​range from 1.2 to 1.5, increasing with the strength grade of the frame material). This is the structural damping correction factor (values ​​range from 0.8 to 0.95, determined by the number of welded joints in the frame). For the first One initial resonant frequency (Hz); The peak value of residual stress (MPa) detected at the corresponding frequency. This represents the total number of resonant frequencies. If the vibration aging process is deemed ineffective, the optimal resonant frequency is used to perform the first stage of residual stress elimination until the vibration aging process becomes effective; or the optimal resonant frequency is used directly to perform the entire first stage of residual stress elimination.

[0048] The above scheme achieves precise frequency selection for "stress guidance" by establishing a dynamic correlation formula between the resonant frequency and residual stress. Regarding stress relief efficiency, it introduces a stress sensitivity coefficient. and structural damping correction factor To achieve the optimal resonant frequency It can specifically match the vibration requirements of high-stress areas; The introduction of (peak residual stress at the corresponding frequency) allows the frequency selection for different batches of frames to adapt to differences in stress distribution; by avoiding excessive vibration in low-stress areas, unnecessary energy input is reduced, lowering the risk of microcracks in the frame; complementing the "Method for Evaluating the Effect of Vibration Aging," it transforms frequency selection from experience-driven to data-driven, making the vibration aging process traceable and controllable. On-site operators can directly call the formula calculation results through the control system, reducing human intervention.

[0049] Optionally, in some other implementations, the traditional vibration aging treatment of bogie frames uses a fixed proportion for the excitation force (such as 30% of the maximum excitation force in the original scheme), which has significant technical limitations. This mode does not consider the synergistic effects of the initial residual stress state of the frame, the mechanical properties of the materials, and the resonant frequency, resulting in a mismatch between the excitation force and the stress attenuation requirements. In view of this, a quantitative matching formula for excitation force and residual stress attenuation is proposed, including: (2); in, The optimal excitation force (N) is used. The maximum excitation force of the system (N); The initial residual stress (MPa) before vibration aging; The yield strength of the framework material (MPa); Optimal resonant frequency (Hz).

[0050] The above matching formula, by introducing initial residual stress, material yield strength, and optimal resonant frequency parameters, achieves dynamic adaptive control of the excitation force, allowing for dynamic adjustment of the excitation force according to the actual stress state; through Limit the upper limit of excitation force, when this ratio When the value is less than 0.3, the increase in excitation force is suppressed, avoiding excessive vibration of low-stress components. For a frame with a yield strength of 460 MPa, even if the initial stress reaches 200 MPa, the calculated excitation force is still controlled at 38% of the maximum force, which is far below the safety threshold (50%) corresponding to the material's yield limit, and no secondary stress concentration phenomenon occurs.

[0051] Optionally, in some other implementations, to address the lack of a quantitative synergistic evaluation method for the two-stage treatment of "overall vibration aging + local ultrasonic shock", a synergistic effect coefficient formula for two-stage stress relief is proposed, including: (3); in, Total stress relief rate (%) The stress relief rate (%) for the first stage of vibration aging is calculated using the standard curve of the "Method for Evaluating the Effect of Vibration Aging"; The stress relief rate (%) of the second-stage ultrasonic impact is calculated from the stress test values ​​before and after the impact. The synergy coefficient is set at 1.1 to 1.3, with the upper limit taken when the overlap between the peak residual stress zone of the first stage and the impact zone of the second stage is >80%. The above scheme achieves precise control of process synergy by quantifying the matching degree and superposition effect of the two stages, thereby enabling continuous switching between the first and second stage treatments to achieve the optimal coordinated treatment effect.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. 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 synergistic elimination of residual welding stress in welded components, characterized in that, The process includes the following: The welded components are subjected to spectral harmonic vibration aging treatment to eliminate residual stress in the first stage of the welded components. After the first stage of residual stress elimination is completed, the residual stress distribution state of the welded component after the initial residual stress elimination is obtained. Based on the residual stress distribution state, the area to be eliminated where the welding tensile stress is greater than the first set threshold and the working load is greater than the second set threshold is selected. The area to be eliminated is subjected to local ultrasonic impact treatment of the weld seam to eliminate residual stress in the welded component in the second stage, until all residual stress in the area to be eliminated is eliminated.

2. The method for synergistic elimination of residual welding stress in welded components as described in claim 1, characterized in that, The aging treatment of welded components for spectral harmonic vibration includes: Spectral analysis was performed to obtain the optimal multiple resonant frequencies of the welded component and sort them. Vibration aging was performed in sequence according to the resonant frequencies, and the vibration aging curves at each frequency were recorded. After the vibration aging at each frequency was completed, the frequency sweep curve after vibration aging was recorded. The effectiveness of vibration aging is determined based on the vibration aging curves and the frequency sweep curve after vibration aging. If effective, the residual stress elimination in the first stage is completed. If ineffective, the residual stress elimination process in the first stage is repeated until the vibration aging is effective.

3. The method for synergistic elimination of residual welding stress in welded components as described in claim 1, characterized in that, Local ultrasonic impact treatment of the weld seam in the area to be treated includes: The impact range from the weld toe to the base material is within the set range, and the impact ranges on both sides of the weld are the same or the difference in impact ranges is within the set range.

4. A system for synergistically eliminating residual stress in welded components, characterized in that, It includes a spectrum harmonic vibration aging treatment subsystem, a stress testing unit, and an ultrasonic shock treatment subsystem; A spectrum harmonic vibration aging treatment subsystem is used to perform spectrum harmonic vibration aging treatment on welded components in order to eliminate residual stress in the first stage of the welded components. The stress testing unit acquires the residual stress distribution of the welded component after preliminary residual stress elimination. Based on the residual stress distribution, it selects the area to be eliminated where the welding tensile stress is greater than the first set threshold and the working load is greater than the second set threshold. The ultrasonic impact treatment subsystem performs local ultrasonic impact treatment on the weld seam in the area to be eliminated, so as to eliminate residual stress in the second stage of the welded component.

5. The welding residual stress synergistic elimination system for welded components as described in claim 4, characterized in that, The spectrum harmonic vibration aging treatment subsystem is communicatively connected to the stress testing unit, and the stress testing unit is communicatively connected to the ultrasonic impact treatment subsystem. After the spectrum harmonic vibration aging treatment subsystem completes the first stage of residual stress elimination, it sends a completion notification to the stress testing unit. The stress testing unit then initiates stress detection and sends the detected area to be eliminated to the ultrasonic impact treatment subsystem for the second stage of residual stress elimination.

6. The welding residual stress synergistic elimination system for welded components as described in claim 4 or 5, characterized in that, The ultrasonic impact treatment subsystem includes an impact head, an amplitude transformer, a transducer, and an ultrasonic impact control module. The ultrasonic impact control module is communicatively connected to the transducer, and the transducer is connected to the impact head through the amplitude transformer. Ultrasonic energy is transmitted to the impact head through the transducer and the amplitude transformer, and the impact head is used to eliminate the residual stress in the second stage of the weld.

7. The welding residual stress synergistic elimination system for welded components as described in claim 6, characterized in that, After the second stage of residual stress elimination is completed, the stress testing unit evaluates the area to be eliminated again, and continues the second stage of residual stress elimination treatment on the remaining areas until there are no new areas to be eliminated.

8. The welding residual stress synergistic elimination system for welded components as described in claim 4 or 5, characterized in that, The spectrum harmonic vibration aging treatment subsystem includes: a rubber pad, a vibrator, a sensor, and a spectrum harmonic vibration aging control module. The spectrum harmonic vibration aging control module is communicatively connected to the vibrator and the sensor, respectively. The welding components are arranged on rubber pads, and the exciter and sensor are detachably connected to the welding components. The spectrum harmonic vibration aging control module automatically performs spectrum analysis to obtain the optimal multiple resonant frequencies of the welding components and sorts them. Vibration aging is performed sequentially according to the resonant frequencies, and the vibration aging curves at each frequency are recorded. After the vibration aging at each frequency is completed, the frequency sweep curve after vibration aging is recorded. The effectiveness of vibration aging is determined based on the vibration aging curves and the frequency sweep curve after vibration aging. If it is effective, the residual stress elimination in the first stage is completed. If it is ineffective, the residual stress elimination process in the first stage is repeated until the vibration aging is effective.

9. The welding residual stress synergistic elimination system for welded components as described in claim 8, characterized in that, At least two sensors are magnetically attached to the edge of the welded component, and the vibrator is fixed to the welded component with bolts.

10. The welding residual stress synergistic elimination system for welded components as described in claim 8, characterized in that, The optimal resonant frequency for residual stress elimination in the first stage is: in, The optimal resonant frequency; This is the stress sensitivity coefficient; This is the structural damping correction factor; For the first One initial resonant frequency; This represents the peak value of residual stress detected at the corresponding frequency; This represents the total number of resonant frequencies. If the vibration aging process is deemed ineffective, the optimal resonant frequency is used to perform the first stage of residual stress elimination until the vibration aging process is effective.

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