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Journal of Environmental Sciences 2020年第4期32卷 364-374页

作者： Peidong Su Junke Zhang Yadong Li Department of Civil&Environmental Engineering Jackson State UniversityJacksonMS39217USA

The leaching concentrations of different metals in stainless steel pickling residue(SSPR)were determined and the toxic metals were treated using Na2 S·xH2 O,FeSO4·6 H2 O,and phosphoric acid.A modified European Community Bureau of Reference(BCR)sequential extraction was used to identify the speciation of the concerned *** showed that SSPR contains a large amount of Ca(58.41%),Fe(29.44%),Cr(3.83%),Ni(2.94%),Mn(2.82%)and some of Al,Cu,Mg,*** them,Cr and Ni were the most toxic metals in SSPR,thus the raw SSPR falls into hazardous waste category due to the leaching amount of *** addition,the leached Cr was identified as Cr6+(MgCr04)in the *** test revealed that risk assessment code(RAC)of Cr and Ni were 33.29%and 61.7%,indicating they posed"high"and"very high"risk to the environment,*** fixing by Na2 S·xH2 O and FeSO4·6 H2 O,the leaching concentrations of Cr and Ni were less than 1.5 and 0.5 mg/L,*** fixing by Na2 S·xH2 O and FeSO4·6 H2 O the tre ated SSPR can be safely reused as roadbed materials,concrete and cement *** study provides a useful implication in treatment and beneficial reuse of heavy metal-containing hazardous wastes.

关键词： Stainless steel pickling residue Leaching toxicity Cr(Ⅵ) Chemical fixation Beneficial reuses

Effect of Zn Vaporization on Wetting of Al-galvanized Steel in Cold Metal Transfer Process

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Journal of Iron and Steel Research International 2016年第6期23卷 566-572页

作者： Qiao-li LIN Gao-jun MAO Qian HUANG Rui CAO Jian-hong CHEN state Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metal Lanzhou University of Technology

The wetting of galvanized steel by molten Al alloys was studied in the cold metal transfer process by the sessile drop method using a high speed video *** wetting behavior can be divided into two typical cases,trending of non-wetting by using small wire feeding speed and wetting by using large wire feeding *** Leidenfrost effect is caused by the volatilization of Zn,which is responsible for the former *** enhanced wettability of steel by Al and the weakening of the Leidenfrost effect are responsible for the latter *** is the destabilizing factor for Al-steel joining that needs to be avoided by a reasonable design of process.

关键词： wetting camera evaporation latter weakening trending feeding boiling joining metallic

Effects of Quenching Process on Microstructure and Mechanical Properties of Low Carbon Nb-Ti Microalloyed Steel

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Journal of Harbin Institute of Technology(New Series) 2013年第4期20卷 73-77页

作者： Wen-Zhen Xia Xian-Ming Zhao Xiao-Ming Zhang Di Wu state Key Laboratory of Rolling and Automation Northeastern University

The low carbon Nb-Ti mieroalloyed tested steel was prepared by the process of vacuum induction furnace smelting, forging and hot rolling. The new steel aims to meet the demand of high strength, high toughness and high plasticity for building facilities. The effects of quenching process on microstructure and mechanical properties of tested steel were investigated. The results showed that prior austenite grain size, phase type and precipitation behavior of （ Nb, Ti）（ C, N） play important roles in mechanical properties of the steel. Through modified appropriately, the model of austenite grain growth during heating and holding is d^5.7778 = 5. 6478^5.7778 ＋ 7.04 × 10^22t^1.6136 exp（- 427. 15 ×10^3 /（RT））. The grain growth activation energy is Qg = 427. 15 kJ. During quenching, the microscopic structures are mainly martensite and lath bainite which contains lots of lath substructure and dislocations. The content of phases, fine and coarsening （ Nb, Ti ）（ C, N ） precipitated changes during different quenching temperatures and holding time. Finally compared with the hardness value, the best quenching process can be obtained that heating temperature and holding time are 900 ℃ and 50 mins, respectively.

关键词： low carbon Nb-Ti mieroalloyed steel quenching process austenite grain growth model microstructure and mechanical properties

Influence of Nb addition on microstructural evolution and compression mechanical properties of Ti-Zr alloys

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Journal of Materials Science & Technology 2021年第10期69卷 7-14页

作者： Pengfei Ji Bohan Chen Bo Li Yihao Tang Guofeng Zhang Xinyu Zhang Mingzhen Ma Riping Liu state Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004China

In order to expand the application horizon of Ti-Zr based alloys,the influence of Nb content on phase composition,microstructural evolution and biomechanical properties is systematically *** phase and microstructural characterization of the as-cast alloys is carried out by X-ray diffraction,optical microscopy and transmission electron *** results reveal that Nb-containing Ti-Zr alloys transformed from single a phase→α+α"+β phase single β phase double β phases with increasing Nb *** the case of β-type alloys,the addition of Nb improves the bonding energy between atoms,reduces the grain size,increases the elastic modulus,improves the yield strength and renders superior work-hardening ***,the current study provides mechanistic insights into microstructural evolution and strengthening of Nb-containing Ti-Zr alloys with increasing Nb ***,the addition of 5 at.% Nb resulted in an abnormal work hardening during compression deformation under the synergistic influence of stress-induced martensite transformation of β phase and stress-induced twinning of α ***,the biomechanical properties are evaluated to demonstrate the potential of Nb-containing Ti-Zr alloys in biological applications.

关键词： Ti-Zr based alloy Biomaterials Microstructural evolution Mechanical properties

THE EFFECT OF SILICA MORPHOLOGY ON PROPERTIES OF PVA/SILICA NANO-COMPOSITES

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Chinese Journal of Polymer Science 2013年第11期31卷 1546-1553页

作者： Lei Bi Jin-wen Wang 陈枫傅强 College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan University

Two kinds of poly（vinyl alcohol）（PVA）-silica composites were prepared with different methods. One composite was prepared by directly mixing PVA with 80 nm silica nano-particles which were made from tetraethoxysilane （TEOS）. The another was obtained by the mixing PVA and hydrolyzed TEOS in the presence of acid-catalyst. The properties of the two PVA/silica hybrids were characterized by means of scanning electron microscopy （SEM）, UV-Visible spectroscopy, solubility tests, limiting oxygen index （LOI） test, tensile test and dynamical mechanical analysis （DMA）, respectively. The results indicate that PVA-TEOS composites （PT for short） display more transparency than PVA-silica nano-particles hybrids （PS for short）. At the same time, The PT composites presented more excellent performance than PS in water resistance, fire resistance and mechanical properties. Moreover, the Tg of PT increased with increasing TEOS content, while that of PS decreased.

关键词： Silica Poly(vinyl alcohol) TEOS Network Nano-composite.

Error Analysis of FLC Experimental Data at Warm/Hot Stamping Conditions

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Chinese Journal of Mechanical Engineering 2014年第4期27卷 730-737页

作者： ZHUANG Weimin ZHANG Mengxi CHEN Yanhong state Key Laboratory of Automotive Dynamic Simulation Jilin University Department of Aeronautics Imperial College

Forming limit curves（FLCs） are commonly used for evaluating the formability of sheet metals. However, it is difficult to obtain the FLCs with desirable accuracy by experiments due to that the friction effects are non-negligible under warm/hot stamping conditions. To investigate the experimental errors, experiments for obtaining the FLCs of the AA5754 are conducted at 250℃. Then, FE models are created and validated on the basis of experimental results. A number of FE simulations are carried out for FLC test-pieces and punches with different geometry configurations and varying friction coefficients between the test-piece and the punch. The errors for all the test conditions are predicted and analyzed. Particular attention of error analysis is paid to two special cases, namely, the biaxial FLC test and the uniaxial FLC test. The failure location and the variation of the error with respect to the friction coefficient are studied as well. The results obtained from the FLC tests and the above analyses show that, for the biaxial tension state, the friction coefficient should be controlled within 0.15 to avoid significant shifting of the necking location away from the center of the punch; for the uniaxial tension state, the friction coefficient should be controlled within 0.1 to guarantee the validity of the data collected from FLC tests. The conclusions summarized are beneficial for obtaining accurate FLCs under warm/hot stamping conditions.

关键词： forming limit curve(FLC) error analysis warm/hot stamping finite element analysis

ABRUPT DEFLECTED SUPERCRITICAL WATER FLOW-REVISED THEORY OF SHOCK WAVE

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Journal of Hydrodynamics 2006年第1期18卷 32-39页

作者： NI Han-gen LIU Ya-kun state Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China

The shock wave angle and depth ratio of the abrupt deflected supercritical water flow due to deflector was investigated experimentally and theoretically. A correction coefficient of the hydro-dynamic pressure ξ was introduced to generalize the momentum equation in the perpendicular direction to the shock front. An extensive series of tests were conducted in a 1 m wide flume with the Froude number ranging from 1.70 to 8.37, the deflection angle ranging from 5° to 40° and the length of deflector ranging from 0.28 m to 1 m. A dimensionless parameter K was defined to depict the ratio of the flow height to flow thickness. Test results show that the val ue of ~, the correction coefficient of the non-hydrostatic pres- sure distribution, decreases with the increase of the value of K An empirical relationship between the value of ξ and the val ue of K was proposed. It is indicated that the relative errors of the results calculated by the revised theory is much smaller than that obtained from the Ippen theory. Finally, a simple explicit expression was suggested to calculate the shock wave height ratio in consideration of the effect of the non-hydrostatic pressure distribution.

关键词： theory of shock wave abrupt deflection of supercritical flow trajectory type energy dissipater

Effect of Al2O3/TiO2/Na2O on enrichment of phosphorus in P-bearing steelmaking slag

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Journal of Iron and Steel Research International 2019年第8期26卷 796-805页

作者： Kan Yu Yan-ling Zhang Feng-shan Li Ming Gao state Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing Beijing 100083 China

To explore the influence of Al2O3/TiO2/Na2O on the mineralogical structure and phosphorus enrichment of converter slag, phosphorus enrichment and distribution in the CaO-SiO2-Fe2O3-MgO-Al2O3/TiO2/Na2O slag system were experimen-tally examined. The results show that phosphorus mainly exists in an n2CaO·SiO2-3CaO·P2O5 (nC2S-C3P) solid solution. Al2O3/TiO2/Na2O is beneficial for phosphorus enrichment in the CaO-SiO2-Fe2O3-MgO slag system to various degrees. This allows screening and separation of the enriched phase in the slag. When Al2O3 content was increased from 0 to 15%, the P2O5 content in the P-rich phase increased from 13.88 to 21.32%, and the area of the P-rich phase decreased from 57.50 to 37.87%. When the TiO2 content was increased from 0 to 10%, the content of P2O5 in the P-rich phase increased from 13.88 to 22.90%, and the area of the P-rich phase decreased from 57.50 to 39.20%. When the contents of Al2O3 and TiO2 were increased, the previously formed nC2S-C3P solid solution transformed into n′C2S-C3P (n < n′) with higher phos-phorus content. Na2O had no significant effect on phosphorus enrichment, but exerted significant influence on the area of the P-rich phase. When the Na2O content was increased from 0 to 8%, the previously formed nC2S-C3P solid solution gradually became Na2Ca4(PO4)2SiO4, and the area of the P-rich phase increased from 57.50 to 68.50%. With increasing the content of ATN (a mixture with a mass ratio of Al2O3/TiO2/Na2O = 15:4:3) from 0 to 30%, the content of P2O5 increased from 13.88 to 42.10% and the area of the P-rich phase decreased from 54.92 to 18.40%.

关键词： Phosphorus enrichment nC2S-C3P solid solution Modification P-bearing steelmaking slag

Largely Improved Stretch Ductility and β-Form Room-temperature Durability of Poly(vinylidene fluoride) by Incorporating Aliphatic Polyketone

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Chinese Journal of Polymer Science 2018年第11期36卷 1277-1285页

作者： Shui-Qin Pu Shuo Guo Ke Wang Qiang Fu College of Polymer Science and Engineering Sichuan University State Key Laboratory of Polymer Materials Engineering

In this study, we attempt to prepare a new blending system of poly（vinylidene fluoride）（PVDF） and aliphatic polyketone （POK） by melt compounding, The latter is a promising engineering plastic with comprehensive mechanical performances. When POK acted as minor phase to homogeneously disperse in and intimately contact with PVDF matrix, the brittle tensile behavior of neat PVDF transferred into a remarkably flexible manner （the elongation at break increased for 20 times）, and more interestingly, the room- temperature durability of β-form PVDF in the uniaxially drawn blend film was obviously better than that in the neat PVDF film. Fourier transform infrared spectroscopy revealed that specific dipole interaction existed between CF2 group of PVDF and C=O group of POK. The intermolecular dipolar interaction induced good compatibility in the PVDF/POK blends, as evidently proved by fine two-phase morphology and decreased melting points of POK crystals. Therefore, the good compatibility and interracial enhancement are responsible for the improvement of the stretch ductility and β-form room-temperature durability of the PVDF/POK blends.

关键词： Blend Aliphatic polyketone Dipole interaction Stretch ductility Uniaxially drawn β-PVDF

A novel particle tracking algorithm using polar coordinate system similarity

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Acta Mechanica Sinica 2005年第5期21卷 430-435页

作者： Xiaodong Ruan Wenfeng Zhao The state Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

A new algorithm using polar coordinate system similarity （PCSS） for tracking particle in particle tracking velocimetry （PTV） is proposed. The essence of the algorithm is to consider simultaneously the changes of the distance and angle of surrounding particles relative to the object particle. Monte Carlo simulations of a solid body rotational flow and a parallel shearing flow are used to investigate flows measurable by PCSS and the influences of experimental parameters on the implementation of the new algorithm. The results indicate that the PCSS algorithm can be applied to flows subjected to strong rotation and is not sensitive to experimental parameters in comparison with the conventional binary image cross-correlation （BICC） algorithm. Finally, PCSS is applied to images of a real experiment.

关键词： PIV . PTV . Polar coordinate system similarity .Binary image cross-correlation.