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Effect of welding process on the microstructure and properties of dissimilar weld joints between low alloy steel and duplex stainless steel

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International Journal of Minerals,Metallurgy and Materials 2012年第6期19卷 518-524页

作者： Jing Wang Min-xu Lu Lei Zhang wei chang Li-ning Xu Li-hua Hu Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing 100083 China Research Institute of China National Offshore Oil Corporation Beijing 100027 China

To obtain high-quality dissimilar weld joints, the processes of metal inert gas （MIG） welding and tungsten inert gas （TIG） welding for duplex stainless steel （DSS） and low alloy steel were compared in this paper. The microstructure and corrosion morphology of dissimilar weld joints were observed by scanning electron microscopy （SEM）; the chemical compositions in different zones were detected by en- ergy-dispersive spectroscopy （EDS）; the mechanical properties were measured by microhardness test, tensile test, and impact test; the corro- sion behavior was evaluated by polarization curves. Obvious concentration gradients of Ni and Cr exist between the fusion boundary and the type II boundary, where the hardness is much higher. The impact toughness of weld metal by MIG welding is higher than that by TIG weld- ing. The corrosion current density of TIG weld metal is higher than that of MIG weld metal in a 3.5wt% NaC1 solution. Galvanic corrosion happens between low alloy steel and weld metal, revealing the weakness of low alloy steel in industrial service. The quality of joints pro- duced by MIG welding is better than that by TIG welding in mechanical performance and corrosion resistance. MIG welding with the filler metal ER2009 is the suitable welding process for dissimilar metals jointing between UNS $31803 duplex stainless steel and low alloy steel in practical application.

关键词： dissimilar metals welds stainless steel alloy steel microstructure mechanical properties corrosion

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Catalytic Synthesis of Isopropyl Benzene over SO_4 ^(2-)/ZrO_ 2-MCM-41

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Chemical Research in Chinese Universities 2006年第3期22卷 371-374页

作者： wei chang-ping LI Shu-zeng ZHOU Bin PENG Chun-jia ZHEN Kai-ji College of Materials and Chemical Engineering Changchun University of Science and Technology Changchun 130022 P. R. China Northeast Research Institute of Electronics Technology Jirtzhou 121000 P. R. China College of Chemistry Jilin University Changchun 130021 P. R. China

Super acid catalyst SO4^2-/ZrO2 was introduced into pure silicone MCM-41 via the impregnation method and the catalyst samples obtained at different temperatures were characterized by means of XRD, IR, and Py-IR techniques. The selectively catalytic gas-phase flow reactions of benzene with propene over the catalyst samples were carried out in a made-to-measure high-pressure flow reactor equipped with a thermostat and a condenser. Effect of the preparative condition on the catalytic synthesis of isopropyl benzene over the catalyst samples was tested. The results show that SO4^2-/ZrO2-MCM-41 （ SZM-41 ） can be used as a catalyst for the title reaction, in which there are a higher conversion （97%） for the propene and a higher selectivity（93% ） for the isopropyl benzene.

关键词： Benzene Propene Isopropyl benzene SO4^2-/ZrO2-MCM-41 catalyst

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Solute Distribution in Columnar Crystal Zone and Influences of Correlative Factors for Continuous Casting Slabs

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Journal of Iron and Steel Research International 2008年第4期15卷 21-25页

作者： CHEN Shu-ying chang Guo-wei YUE Xu-dong WU Chun-jing School of Materials University of Science and Technology Beijing Beijing 100083 China College ofMaterial and Chemical Engineering Liaoning University of Technology Jinzhou 121000 Liaoning China

The expression of the solute distribution in columnar crystal zone was deduced when the solid-liquid interface bended periodically, and the quantitative calculations of macrosegregation were also made in the process of the continuous casting. The solute distribution along the thickness direction of the slabs was obtained, which verified the theoretical calculation. The effect of the bulge size, solidification speed, and solidification shrinkage speed on macrosegregation of the slabs was calculated. It can be concluded that normal segregation and negative segregation alternatively appear as a result of the bulge. The normal segregation exponentially depends on the bulge size, and the negative segregation linearly depends on the bulge size. The extent of the normal segregation is greater than that of the negative segregation when the bulge size is the same. The macrosegregation of the same position along the thickness direction of the slabs changes in a sine wave with increasing the solidification rate, and the amplitude is larger at the casting blank center. The normal segregation linearly decreases with increasing the solidification shrinkage speed, and when the solidification shrinkage speed exceeds a critical value, the segregation appears negatively and increases linearly.

关键词： continuous casting columnar crystal zone solute distribution macrosegregation

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Sustainable dropwise condensation enabled ultraefficient heat pipes

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Droplet 2023年第1期2卷 64-72页

作者： wei chang Kai Luo Pengtao Wang Ahmed A.Abdulshaheed Chen Li State Key Laboratory of Automotive Simulation and Control Jilin UniversityChangchunChina Department of Thermal Engineering College of Automotive EngineeringJilin UniversityChangchunChina Department of Mechanical Engineering University of South CarolinaColumbiaSouth CarolinaUSA Oak Ridge National Laboratory Oak RidgeTennesseeUSA

Heat pipes play a critical role in determining the operations,safety,and energy efficiency of *** main focus to improve the heat pipe performance is on the evaporator design or wicking ***,the intrinsic limitation comes from the condenser,which is fundamentally constrained by inefficient filmwise condensation(FWC).In this study,we successfully achieved a peak effective thermal conductivity(keff)of~140 kW/(m·K)on widely used groove heat pipes by implementing sustianble dropwise condensation(DWC)and integrating with enhanced *** better understand the working mechanisms of the ultraefficient heat pipe,both the evaporator and condenser of the heat pipes have been modified *** results show that up to 296%enhancements on the keff can be achieved under various inclination angles by only inducing DWC in the condenser *** drawback of temperature fluctuations induced by DWC in smooth heat pipes appears to be effectively solved using the grooves‐wicking ***,by integrating the nanostructured evaporator,the keff of the heat pipe can be boosted up to 517%compared to conventional groove heat *** study,for the first time,demonstrates the huge potential of engineering both the condenser and evaporator simultaneously in developing ultraefficient heat pipes.

关键词： pipes integrating operations

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δ/δ Grain Boundary Movement in Fe-0.2%C-0.8%Cr During Solidification Process

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Journal of Iron and Steel Research International 2013年第6期20卷 63-67页

作者： YUE Xu-dong LI Qing-chun CHEN Shu-ying chang Guo-wei School of Materials Science and Engineering Liaoning University of Technology

The moving process ofδ / δgrain boundary during the solidification process of Fe-0.2%C-0.8%Cr has been observed in-situ with confocal scanning laser microscope （ CSLM ）, and the establishment of δ/δ grain boundary , the moving mode , the moving speed and the influence of correlative factor were explored in *** results showed that the clear grain cannot be formed when δ phase merged during solidification process of the steel if the actual cooling rate was 0.045℃·s-1 .The δ/δgrain boundary with shape of flat will be formed if there is no essential conjunction betweenδphase in a long period of *** movement ofδgrain boundary cross point drives other δ /δ grain boundaries to *** moving process is not stable , and the moving rate variation ranges from 0.12to 1.65 μ m ·s-1 .Temperature of the system is the chief factor for influencing the moving rate of δ / δgrain boundary during the *** the temperature fluctuation of system appears , the solidified grain boundary is re-melted , which results in the catastrophic fluctuation of moving rate for δ / δ grain *** the solidification process reaches its end , the average moving rate of δ /δ grain boundary is quicker than that of L / δ *** coarsening rate of crystal grain in the melt is slower than that of solidified solid phase crystal grain.

关键词： carbon steel solidification process δ / δ interface insitu observation

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MECHANISM AND EFFECT OF CHANNEL EVOLUTION AT ESTUARY OF weiHE RIVER TO HUANGHE RIVER

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Chinese Geographical Science 2006年第2期16卷 122-126页

作者： LI Jing-yi SHI chang-wei XU Xi-bao FU Zhi-jun Key Laboratory of Western Chin＇s Environmental Systems of Ministry of Education Lanzhou University Lanzhou 730000 P. R. China Key Laboratory of Disaster Survey ＆ Mechanism Simulation of Shaanxi Province Baoji 721007 P. R. China Sanmenxia Reservoir Management Bureau Xi＇an 710000 P. R. China School of Geography Nantong University Nantong 226007 P. R. China

The channel at the estuary of the weihe River to the Huanghe (Yellow) River has changed markedly since the 1970s. The Huanghe River has swung westwards about 5km and there was retrogressive deposition along the weihe River. The mechanism and effect of channel evolution at the entrance of the weihe River to the Huanghe River was analyzed with the survey data, historical statistic data and Landsat TM images of 1987 and 2002. Following conclusions were reached: 1) Physiognomy factors at the entrance, irrigation project and integrated environment evolvement in the weihe River basin are the main factors for channel evolution at the entrance of the weihe River to the Huanghe River. 2) The channel evolution not only reduces the ability of controling flood in the lower reaches of the weihe River due to shrinking of the riverbed, but also increases the flood threat in the lower reaches of the weihe River because the Huanghe River water inversely flows into the weihe River. And there is a complexion of small flux, high water level and big disaster, which leads to the expansion of the alkali-saline cropland in the conflux area of the two rivers. 3) The regionalism and local protection must be broken to implement the integrated planning of the watershed and to decline the height of Tongguan to stabilize the physiognomy at the estuary.

关键词： estuary riverway evolvement retrogressive deposition flood

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Photoproductionγp→K^(+)Λ(1690)in an effective Lagrangian approach

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Chinese Physics C 2022年第5期46卷 44-51页

作者： Neng-chang wei Ai-Chao Wang Fei Huang School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 101408China

A gauge-invariant model is constructed for theγp→K^(+)Λ(1690)reaction within a tree-level effective Lagrangian approach to understand the underlying production mechanisms and study the resonance contributions in this *** addition to the t-channel K and K^(∗)exchanges,s-channel nucleon exchange,and interaction current,the s-channel nucleon resonance exchanges are included in constructing the reaction amplitudes to describe the *** is found that the contributions from the s-channel N(2570)5/2^(−)exchange are required to describe the most recently measured total cross-section data forγp→K^(+)Λ(1690)from the CLAS *** analysis indicates that the interaction current dominates the γ p→K^(+)Λ(1690)reaction near the threshold as a result of gauge *** t-channel K exchange contributes significantly,while the contributions from the t-channel K^(∗)exchange and s-channel nucleon exchange are ultimately *** contributions from the s-channel N(2570)5/2^(−)exchange are found to be responsible for the bump structure shown in the CLAS total cross-section data above the center-of-mass energy W≈2.7 *** predictions of the differential cross sections forγp→K^(+)Λ(1690)are presented and discussed,which can provide theoretical guidance for future experiments.

关键词： K^(+)Λ(1690)photoproduction effective Lagrangian approach gauge invariance

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Pyrolysis of Glucose over Two Amphoteric Metal Oxides

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Chemical Research in Chinese Universities 2009年第2期25卷 234-238页

作者： YANG Yu XIANG Xi LUO Jia QI wei-Yan YAN Hong-Peng LI Gui-Ying HU chang-wei Key Laboratory of Green Chemistry and Technology Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. China

The catalytic pyrolysis of glucose over amphoteric metal oxide, ZnO or γ-l2O3, was studied comparatively with direct pyrolysis. The effects of catalyst to glucose ratio on the yields of pyrolytic products and on the chemical composition of the liquid products were discussed. Compared with the pyrolytic products of direct pyrolysis, the amount of residual char decreased, whereas the gas yield increased in the presence of the catalysts. The highest liquid yield over ZNO（49.5%） was obtained when the ratio of ZnO to glucose was 5%, whereas over γ-Al2O3 the liquid yield increased with increasing the amount of γ-Al2O3 added. The presence of both the catalysts enhanced the selectivity to furans in liquid and reduced that of anhydro sugars. A selectivity of 69.7% to furans was obtained over 1% ZnO with a selectivity of 14.6% to 5-hydroxymethylfurfural（HMF）. The maximum selectivity to furans（74.9%） and that to HMF（25.6%） were obtained in the presence of 10% γ-Al2O3.

关键词： Glucose ZnO γ-Al2O3 Furans 5-Hydroxymethylfurfural

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Photoproduction reactionγn→K^(*0)∧in an effective Lagrangian approach

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Chinese Physics C 2022年第2期46卷 57-61页

作者： Neng-chang wei Yi-Ming Zhu Fei Huang School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 101408China School of Physical Sciences University of Chinese Academy of SciencesBeijing 101408China

In our previous work[***.C 101,014003(2020)],the photoproduction reactionγp→K^(*+)Λwas investigated within an effective Lagrangian *** reaction amplitudes were constructed by including the t-channel K,K^(*),and k exchanges,u-channelΛ,∑,and∑^(*)exchanges,s-channel N,N(2000)5/2^(+),and N(2060)5/2^(-)exchanges,and interaction *** data on the differential cross sections and spin density matrix elements were described *** this study,we investigate the photoproduction reactionγn→K^(*0)Λbased on the same reaction mechanism as that ofγp→K^(*+)Λto obtain a unified description of the data forγp→K^(*+)Λandγn→K^(*0)Λwithin the same *** hadronic coupling constants,form factor cutoffs,and the resonance masses and widths in the present calculations remain the same as in our previous work forγp→K^(*+)Λ.The available differential cross-section data forγn→K^(*0)Λare well *** analysis shows that the cross sections ofγn→K^(*0)Λare dominated by the contributions of the t-channel K exchange,while the s-channel N(2000)5/2+and N(2060)5/2-exchanges also provide considerable contributions.

关键词： photoproduction effective Lagrangian approach gauge invariance

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Manipulating metal-oxygen local atomic structures in singlejunctional p-Si/WO_(3) photocathodes for efficient solar hydrogen generation

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Nano Research 2021年第7期14卷 2285-2293页

作者： Wu Zhou Chung-Li Dong Yiqing Wang Yu-Cheng Huang Lingyun He Han-wei chang Shaohua Shen International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityShaanxi 710049China Department of Physics Tamkang UniversityTamsui 25137TaiwanChina

Self-passivation in aqueous solution and sluggish surface reaction kinetics significantly limit the photoelectrochemical(PEC)performances of silicon-based ***,a WO_(3) thin layer is deposited on the p-Si substrate by pulsed laser deposition(PLD),acting as a photocathode for PEC hydrogen *** to bare p-Si,the single-junctional p-Si/WO_(3) photoelectrodes exhibit excellent and stable PEC performances with significantly increased cathodic photocurrent density and exceptional anodic shift in onset potential for water *** is revealed that the WO_(3) layer could reduce the charge transfer resistance across the electrode/electrolyte interface by eliminating the effect of Fermi level pinning on the surface of *** importantly,by varying the oxygen pressures during PLD,the collaborative modulation of W–O bond covalency and WO6 octahedral structure symmetry contributes to the promoted charge carrier transport and ***,a large band bending at the p-Si/WO_(3) junction,induced by the optimized O vacancy contents in WO_(3),could provide a photovoltage as high as~500 mV to efficiently drive charge transfer to overcome the water reduction ***,by manipulating W–O local atomic structures in the deposited WO_(3) layer,a great improvement in PEC performance could be achieved over the singlejunctional p-Si/WO_(3) photocathodes for solar hydrogen generation.

关键词： silicon local atomic structure water splitting photocathodes hydrogen generation

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