Acoustic emission characteristics in eccentric rotary cropping process of stainless steel tube

Li, Jingxiang; Qiu, Hao; Zhang, Dawei; Zhao, Shengdun; Zhao, Yongqiang

doi:10.1007/s00170-017-0174-8

Cited by 10 publications

(11 citation statements)

References 20 publications

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“…18 A more stable parameter is needed to describe the fracture stage. According to the previous study, 12,31 the kurtosis iswas found to have a better effect to represent the status of the fracture process. Therefore, the kurtosis is used in this study to represent the fracture stage.…”

Section: Resultsmentioning

confidence: 90%

“…For some materials, the counts decreases during the fracture stage, such as stainless steel. 12 For some materials, the counts increases during the fracture stage, such as micro-alloyed steel. 18 A more stable parameter is needed to describe the fracture stage.…”

Section: Resultsmentioning

confidence: 99%

“…However, the influences of material defects, geometric parameters, loading frequency and other factors were different in each stage of the LCFC process. 12 . If the effects of the parameters on the each stage of cropping process are clear, the higher productivity and the better cross-section quality will be obtained by applying suitable parameter on each stage of cropping process.…”

Section: Introductionmentioning

confidence: 99%

“…Our project team focuses on LCFC technology. In our previous report, 12 the AE technique was applied to monitor the crack initiation, propagation and final fracture of stainless steel 304 tubes during the LCFC process. The influence of high-frequency load condition and low-frequency load condition was compared in this study.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The investigation of low-cycle fatigue crack propagation of 16 Mn eccentric bar based on the acoustic emission technique

Ren

Dong

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part B:

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Compared to the traditional cropping technology, low-cycle fatigue cropping can reduce load and improve cross-section quality. Geometric factors of V-shaped notch and processing parameters (such as load amplitude and load frequency) influence the cropping efficiency and section quality. By changing the factors, the sufficient efficiency of cropping and quality of cross-section get together. However, the influences of material defects, geometric parameters, loading frequency and other factors are different in each stage of the whole cropping process. If the effects of the parameters on the each stage of cropping process are clear, the higher productivity and the better cross-section quality will be obtained by applying suitable parameter on each stage of cropping process. To investigate the effects of eccentric ratio on each stage of low –cycle fatigue cropping process, a suitable monitoring method is needed. This study proposes acoustic emission (AE) technique to detect the low-cycle fatigue cropping process of 16 Mn eccentric bar (The bar prefabricated eccentric notches. The prefabricated notch improve the efficiency of cropping). The parameters of signals such as counts and kurtosis during the low–cycle fatigue process are obtained. According to the counts changes over time, the process of the 16 Mn metal bar cropping can be divided into three stages: the crack initiation stage, the crack propagation stage, and the fracture stage. Based on the cumulative counts, the eccentric ratio’s influence on the time of each cropping process stage is obtained. The time of the crack initiation stage and the final fracture stage doesn’t increase with the eccentric ratio. The time of the propagation stage influenced by the eccentric ratio greatly. Besides, the eccentric ratio’s influence on the cross-section quality is studied by using an advanced optical microscope system. The cross-section quality was influenced by the eccentric ratio significantly. The results of the paper indicate the acoustic emission (AE) monitoring technique is a useful method to detect the process of low-cycle fatigue cropping. Especially, it provide effective information to investigate the effects of the notch eccentric ratio during the low-cycle fatigue cropping process. The eccentric ratio’s effects on each stage of low-cycle fatigue cropping process offer guidance to improve low-stress fatigue cropping efficiency and cross-section quality.

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Section: Resultsmentioning

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The investigation of low-cycle fatigue crack propagation of 16 Mn eccentric bar based on the acoustic emission technique

Ren

Dong

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part B:

Self Cite

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show abstract

“…Several precise cropping methods have been proposed to improve the section quality by changing irregular ductile fracture into controllable brittle or quasi-brittle fracture, mainly including low-load fatigue cropping, pre-shearing cropping, and high-speed shearing. The low-load fatigue cropping method prefabricates V-shape notches and applies a low-frequency cyclic load to complete fracture [ 1 , 2 ]. In this process, fatigue cracks initiate from the notch tips and propagate steadily, which is controlled by loading curves with decreasing frequency [ 3 ].…”

Section: Introductionmentioning

confidence: 99%

Investigation of Fracture Behavior and Mechanism in High-Speed Precise Shearing for Metal Bars with Prefabricated Fracture-Start Kerfs

et al. 2020

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A laser-assisted high-speed shearing (LAHSS) method has been proposed for metal bars, which prefabricates equally spaced fracture-start kerfs by Nd:Yag laser to make stress concentration, and applies a high-speed load to complete fracture separation. Comparative tests were conducted for Q235, 40Cr, and 304 steel bars, and the effects of fracture-start kerfs and axial clearance were investigated on the fracture section. Moreover, the fracture behavior was demonstrated by numerical simulation, and the micro-fracture mechanism was revealed by fractographic analysis. The numerical simulation results show that the material damage concentrates along with the kerf tips with peak equivalent plastic strain, and the corresponding stress triaxiality drops to almost zero at the kerf tip, which reveals that the material is subjected to pure shearing at kerf tip; the Max. loading force is reduced by 15.2%–29.6%, and the impact energy is decreased by 29.8%–46.9% for the three types of bar material. The experimental results showed that the fracture-start kerfs effectively inhibited the plastic deformation stage, and higher precision blanks were obtained in the LAHSS test: roundness error improved from 2.7%–10.9% to 1.1%–2.6%, Max. bending deflection decreased from 1.3–3.4 mm to 0.4–1.0 mm, and flatness error dropped from 0.9–3.3 mm to 0.3–0.7 mm. The fractographic analysis reveals that the crack initiation is related to alternative V-shape micro-notches at the laser-affected zone; the predominant fracture mechanism involves mode II microvoid coalescence at the main fracture plane; smaller and less elongated dimples were formed in 40Cr steels due to higher number density of grains and pinning effect of second-phase particles compared to Q235 and 304 steel bars.

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The investigation of fracture characteristics and process optimization of low-cycle fatigue cropping by using an AET-based multi-sensor system

Ren

Liu

Zhang

et al. 2023

Int J Adv Manuf Technol

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Acoustic emission characteristics in eccentric rotary cropping process of stainless steel tube

Cited by 10 publications

References 20 publications

The investigation of low-cycle fatigue crack propagation of 16 Mn eccentric bar based on the acoustic emission technique

The investigation of low-cycle fatigue crack propagation of 16 Mn eccentric bar based on the acoustic emission technique

Investigation of Fracture Behavior and Mechanism in High-Speed Precise Shearing for Metal Bars with Prefabricated Fracture-Start Kerfs

The investigation of fracture characteristics and process optimization of low-cycle fatigue cropping by using an AET-based multi-sensor system

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