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Wang Y.,Academy of Armored force Engineering | Zhu Y.,Academy of Armored force Engineering | Huang Y.,Academy of Armored force Engineering | Zhao Q.,63961 Army | And 2 more authors.
Jixie Qiangdu/Journal of Mechanical Strength | Year: 2014

Analysis on fracture failure of suspension spring of an heavy vehicle was carried out by the means of observation of fracture surface, physical chemistry test, analysis of process technology and servicing conditions, and the reason of fracture was found. The analysis indicates that, because of the contact concept between the bearing coil and the first active coil was used, the both coils discussing in previous sentence would collide and wear, then phosphate layer and painting were worn out, and the wire of spring was attacked by corrosion. Then, the fatigue crack was generated by the stress concentration induced by the corrosion pits, and propagated slowly under the main principle stress, finally, the spring failed in the model of normal tensile fracture. In the end, some recommendations were put forward in order to avoid this type of fracture.


Wen C.,Beihang University | Xu G.-X.,Shenyang Aircraft Design Institute | Fan L.-W.,PLA Military Representative Office in Shenyang Aircraft Industries Group Co. | Chen Y.-Z.,Shenyang Aircraft Design Institute
Dongbei Daxue Xuebao/Journal of Northeastern University | Year: 2015

The corrosion behaviors of 20Cr9Ni5Co14 ultra high strength steel (USS) were studied by the electrochemical polarization methods (potentiodynamic polarization, linear polarization and cyclic polarization technologies) and alternating current impedance spectrum methods in different corrosion conditions, and after polarization the corrosion morphologies were characterized by Scanning Electron Microscopy (SEM). The results showed that the passivation phenomenon of 20Cr9Ni5Co14 steels appeared in 3.5 wt.% NaCl solution while disappeared with the increase of NaCl concentration. The corrosion current also reduced from 8.223×10-7 A/cm2 to 1.129×10-7 A/cm2 with the increase of NaCl concentration. The passivation and transpassivation potentials of 20Cr9Ni5Co14 steels increased with the increase of hydrogen ion concentrations. When the pH value was higher than 3, the corrosion product film had excellent corrosion resistancewhich led the electrochemical polarization step as a dominated step, while the pH value decreased to 2, the corrosion products dissolution rate was fast, the corrosion rate of the interface of the metal surface and the solution was also fast, thus the polarization caused by concentration differences became the dominated step. Corrosion morphology studies showed that the corrosion of 20Cr9Ni5Co14 steels in the polarization process oriented from pitting corrosion, which leads to the reduction of corrosion resistance. ©, 2015, Northeastern University. All right reserved.


Yu M.,Beihang University | Dong Y.,PLA Military Representative Office in Shenyang Aircraft Industries Group Co. | Wang R.-Y.,Beihang University | Qi J.-Y.,Beihang University | And 2 more authors.
Cailiao Gongcheng/Journal of Materials Engineering | Year: 2012

The corrosion behavior of ultra-high strength steel 23Co14Ni12Cr3Mo was investigated by three accelerated corrosion methods, alternating immersion corrosion, neutral salt spray and full immersion tests, and electrochemical impedance spectroscopy in simulated seawater environment. The morphology of corrosion products was observed by SEM and the composition was analyzed by X-ray diffraction. The results show that the corrosion product layer is composed of outer rust layer γ-FeOOH and inner rust layer α-FeOOH. The corrosion process begins with pit corrosion, then the corrosion area expands and the uniform corrosion forms with the corrosion time. The corrosion of extend is worst alternating immersion corrosion test, simulated alternation of wetting and drying seawater environment.


Qiao Y.-L.,AVIC Shenyang Aircraft Corporation | Sha C.-P.,AVIC Shenyang Aircraft Corporation | Dong Y.,PLA Military Representative Office in Shenyang Aircraft Industries Group Co. | Liu B.,AVIC Shenyang Aircraft Corporation
Yejin Fenxi/Metallurgical Analysis | Year: 2016

The potentiodynamic polarization scanning of eletrodeposited chromium electrolyte was conducted with three-electrode system using spectroscopically pure graphite electrode as working electrode. Based on the variation relationship between reducing peak current and oxidizing peak current of mass concentration of electro-active materials on graphite electrode surface, the determination method of Cr6+ and Fe2+ in eletrodeposited chromium electrolyte by linear sweep voltammetry was established. The results showed that the optimal experimental conditions were as follows: the scanning rate was 50-60 mV/s, the pH was 2.0, and the testing temperature was 20℃. Cr6+ was reduced at 0.43 V (vs. saturated calomel electrode, SCE). The mass concentration of Cr6+ in range of 2-14 g/L showed linearity to the reducing peak current, and the correlation coefficient of linear regression equation was R2=0.999. Fe2+ was oxidized at 0.52 V (vs. SCE). The mass concentration of Fe2+ in range of 5-15 g/L showed linearity to the oxidizing peak current, and the correlation coefficient of linear regression equation was R2=0.998.The proposed method was applied to the determination of Cr6+ and Fe2+ in actual chromium electrolyte. The relative standard deviations (RSD, n=10) were between 1.1% and 1.3%. The determination results were compared with those obtained by ammonium ferrous sulfate titration for Cr and atomic absorption spectrometry for Fe. The consistency was good. © 2016, CISRI Boyuan Publishing Co., Ltd. All right reserved.


Cheng J.-F.,PLA Air Force Aviation University | Dong X.-M.,PLA Air Force Aviation University | Chen A.-H.,PLA Air Force Aviation University | Dong Z.,PLA Military Representative Office in Shenyang Aircraft Industries Group Co.
Xi Tong Gong Cheng Yu Dian Zi Ji Shu/Systems Engineering and Electronics | Year: 2012

For a type of Takagi-Sugeno (T-S) fuzzy systems with norm-bounded parameter uncertainties, the problem of designing a guaranteed cost robust flight control law with constraints is researched allowing for the guarantee of the various performance indexes and variable constraints via the state feedback parallel-distributed compensation. A constraint fuzzy optimal guaranteed cost control theorem is proposed through modification of the input, output and state linear matrix inequality (LMI). A fuzzy system robust disturbance resistant theorem is also proved with the uncertainty matrix to overcome the parameter perturbation, and the constraint fuzzy optimal guaranteed perturbation immunity theorem is derived on the basis above. Finally, the aircraft T-S fuzzy model is found and the flight control laws satisfying the preceding three theorems are designed respectively. The simulation and comparison are given and the results validate its effectiveness.


Li Z.-M.,Academy of Armored force Engineering | Zhu Y.-L.,Academy of Armored force Engineering | Xie J.-F.,Academy of Armored force Engineering | Du X.-K.,Academy of Armored force Engineering | And 2 more authors.
Hangkong Cailiao Xuebao/Journal of Aeronautical Materials | Year: 2013

The strengthening treated samples of 30CrMnSiNi2A alloy steel were prepared by pneumatic shot peening equipments, and microstructure and mechanical properties of the samples surface layer were analyzed. Microstructures of the samples surface layer were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The surface layers' hardness and residual stress distributions along the thickness direction of the samples with and without shot peening treatment were measured by nano-indention and X-ray diffraction method. The results showed that the organization of untreated sample is lath martensite and a small amount of bainite, twinning, and retained austenite. A plastic deformation layer was formed by the shot peening treatment, and the depth extended up to about 30 μm. The average grain size was about 46 nm in this layer which hardness average values was up to 6.83 GPa, and increased 4.9% than the untreated sample. At the same time, a residual compressive stress layer was also produced by shot peening treatment, and the depth was close to 300 μm. The maximum compressive residual stress was -1050 MPa. At last, the grain refinement mechanism of shot peening treatment and effect on work hardening, compressive residual stress were discussed.


Zhou X.,Shenyang Aircraft Design Institute | Sun X.,Shenyang Aircraft Design Institute | Bing Y.,PLA Military Representative Office in Shenyang Aircraft Industries Group Co. | Yang B.,Nanjing University of Aeronautics and Astronautics
Shuju Caiji Yu Chuli/Journal of Data Acquisition and Processing | Year: 2014

The information of drogue containing position and size are used to establish Kalman filter equations. The model parameters are set considering drogue's motion features in refueling process and the object occlusion coefficient is introduced to complete the parameters' adaptive adjustment. The next-time states of moving drogue are estimated by the model and the estimation is corrected by observation. The experimental results show that the algorithm can track the drogue stably in work distances. When non-target moving objects appear in the images or the drogue is obscured, the algorithm still has the ability of continuous tracking. ©, 2014, Nanjing University of Aeronautics an Astronautics. All right reserved.


He F.,Shenyang Aircraft Design Institute | Chen H.-F.,PLA Military Representative Office in Shenyang Aircraft Industries Group Co. | Wang Y.-H.,Aerospace Research Institute of Materials And Processing Technology
Cailiao Gongcheng/Journal of Materials Engineering | Year: 2012

The effect of microstructure on the high tensile properties at 500°C of TA15 titanium alloy was studied. The results show that the increase of primary α phase content, the strengthening of α phase directional, the thickening of secondary α lamellae or the increase of β grain size can reduce the high temperature tensile at 500°C of TA15 titanium alloy. The largest decrease of high temperature tensile is more than 90MPa by changing the microstructure. The analyses show that the number of grain boundaries is increasing with primary α phase content, and the descent speed of grain boundary strength is faster than that of the grain with the increase of temperature, resulting in the decrease of high temperature tensile.

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