检索结果-南通市图书馆

Journal of Wuhan University of Technology(Materials Science) 2012年第1期27卷 27-32页

作者： XIAO Kui ZHAng Xin d0ng chaofang WEI dan WAng Chen LI Xiaogang Advanced Material and Technology Institute University of Science&Technology BeijingBeijing 100083China Society Service Center China Association for Science and TechnologyBeijing 100081China Faculty of Metallurgical and Energy Engineering Kunmming University of Science and TechnologyKunming 650093China

The corrosion behaviors of Fe-Cr alloy under three different pH values solutions with C1- and SO42- were investigated by localized electrochemical impedance spectroscopy （LEIS） measurements and the corrosion products were analyzed by laser Raman spectrometry. The results show that the high corrosion resistance of Fe-Cr Alloy is attributed to a passive film which is formed more easily when the alloy contains a large quantity of Cr element. However, its corrosion resistance varies in the solutions with different pH values, especially in the initial corrosion. The average impedance values in neutral and alkaline solution are much higher than that in acidic solution because the passive film is more likely to dissolve in the acidic condition. Moreover, the destructive effect of C1- and SO42 ions on the passive film is also demonstrated in corrosion process through the change of the impedance value with the steeping time.

关键词： Fe-Cr Alloy localized electrochemical impedance spectroscopy (LEIS) corrosionproducts Raman spectroscopy

design materials based on simulation results of silicon induced segregation at AlSi10Mg interface fabricated by selective laser melting

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第11期42卷 145-155页

作者： Yuchengji chaofang dong decheng Kong Xiaogang Li Beijing Advanced Innovation Center for Materials Genome Engineering Key Laboratory for Corrosion and Protection(MOE)Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China

AlSi10Mg fabricated by selective laser melting(SLM)had a unique network-like silicon-rich structure,and the mechanism for its formation was explained by molecular dynamics(Md)*** effects of the silicon-rich phase and Mg-containing structure on corrosion were studied by first-principles *** to the simulations,corrosion resistant materials were designed,samples with laser powers of 150 W,200 W and 250 W were *** results indicated that a local thermal gradient during laser printing caused Si segregation,and the rapid cooling rate lead to a large number of subgrains,which assisted *** difference in potential caused galvanic corrosion,and a structure with low work function in the molten pool caused *** corrosion resistance of materials processed with a high laser power increased.

关键词： AlSi10Mg Selective laser melting Atomistic simulation Material design Segregation Corrosion

Pitting and galvanic corrosion behavior of stainless steel with weld in wet-dry environment containing Cl^-

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2007年第6期14卷 517-522页

作者： Cui Lin Xiaogang Li chaofang dong School of Material Science and Technology Nanchang Hangkong University Nanchang 330063 China Corrosion and Protection Center University of Science and Technology Beijing Beijing 100083 China State Key Laboratory for Corrosion and Protection Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Accelerated corrosion test of stainless steel with weld was carried out to investigate the corrosion behavior under the wetdry cyclic condition in the atmosphere containing Cl^-. In the surface morphology, corrosion products were analyzed by metallographic observation, scanning electron microscopy （SEM） and X-ray diffraction （XRd）. The results show that the damage to stainless steel with weld in the atmosphere containing Cl^- is due to localized corrosion, especially pitting and galvanic corrosion, Weld acts as the anode, whereas matrix acts as the cathode in the corrosion process. The pitting corrosion, including the nucleation and growth of a stable pit, is promoted by the presence of wet-dry cycles, especially during the drying stage. Pits centralizing in weld are found to be grouped together like colonies, with a number of smaller pits surrounding a larger pit. The composition of the corrosion products is Fe2O3, Cr2O3, Fe3O4, NiCrO4, etc.

关键词： stainless steel weld wet-dry environment chlorion

Electrochemical corrosion behavior of 300M ultra high strength steel in chloride containing environment

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2010年第4期23卷 301-311页

作者： Min SUN Kui XIAO chaofang dOng Xiaogang LI Corrosion and Protection Center School of Material and Engineering University of Science and Technology Beijing Beijing 100083 China

The electrochemical corrosion behavior of 300M ultra high strength steel in chloride containing environment was investigated by potentiodynamic polarization technique, electrochemical impedance spectroscopy （EIS） and scanning electron microscopy （SEM）. The results show that uniform corrosion occurs on 300M steel during the elec- trochemical measurements because no anodic passivation phenomenon is observed on polarization curves within the measurement range. The tests also show that 300M steel is highly susceptible to chloride containing solution, which is characterized by corrosion current density increasing with the addition of chlorides, and corrosion potential shifting towards positive direction and corrosion resistance decreasing, pos- itively suggesting that chloride ions speed up the corrosion rate of 300M steel. Mean- while corrosion products on the 300M steel surface formed during the salt spray test are too loose and porous to effectively slow down the corrosion rate. Additionally, a schematic structure of uniform corrosion mechanism can explain that 300M steel has better property of stress corrosion cracking （SCC） resistance than stainless steels.

关键词： 300M ultra high strength steel Electrochemical corrosion Chloride

In-situ observation of asymmetrical deformation around inclusion in a heterogeneous additively manufactured 316L stainless steel

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第30期89卷 133-140页

作者： decheng Kong chaofang dong Xiaoqing Ni Zhang Liang Xiaogang Li Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing100083China department of Materials Science and Engineering Massachusetts Institute of TechnologyCambridgeMA02139USA Shanghai Engineering Research Center of 3d Printing Materials Shanghai Research Institute of MaterialsShanghai200437China

Oxide inclusions widely exist in additively manufactured components due to the native oxide layer on the powder surface,together with gas impurities during the printing *** in-situ tensile tests combined with electron backscatter diffraction(EBSd)and electron channeling contrast imaging(ECCI)techniques,we propose an asymmetrical cracking mechanism around the oxide inclusions in a selective laser melted 316L stainless *** heterogeneous sub-micro cellular structures lead to different twinning tendencies around the inclusions due to the size-related critical twinning stresses,and the deformation-induced nano-twin clusters can resist the cracking propagation,therefore resulting in the asymmetrical cracking behaviors around the inclusions.

关键词： Selective laser melting 316L stainless steel Oxide inclusion Asymmetrical crack Cellular structure

Effect of bipolar-plates design on corrosion,mass and heat transfer in proton-exchange membrane fuel cells and water electrolyzers:A review

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1599-1616页

作者： Jiuhong Zhang Xiejing Luo Yingyu ding Luqi Chang chaofang dong Key Laboratory for Corrosion and Protection(MOE) Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering Beijing 100083China

Attaining a decarbonized and sustainable energy system,which is the core solution to global energy issues,is accessible through the development of hydrogen ***-exchange membrane water electrolyzers(PEMWEs)are promising devices for hydrogen production,given their high efficiency,rapid responsiveness,and *** plates account for a relatively high percentage of the total cost and weight compared with other components of ***,optimization of their design may accelerate the promotion of *** paper reviews the advances in materials and flow-field design for bipolar ***,the working conditions of proton-exchange membrane fuel cells(PEMFCs)and PEMWEs are compared,including reaction direction,operating temperature,pressure,input/output,and ***,the current research status of bipolar-plate substrates and surface coatings is summarized,and some typical channel-rib flow fields and porous flow fields are ***,the effects of materials on mass and heat transfer and the possibility of reducing corrosion by improving the flow field structure are ***,this review discusses the potential directions of the development of bipolar-plate design,including material fabrication,flow-field geometry optimization using threedimensional printing,and surface-coating composition optimization based on computational materials science.

关键词： bipolar-plates flow design mass and heat transfer corrosion water electrolyzers fuel cells

Review of key technologies of climbing robots

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2023年第4期18卷 79-96页

作者： Ye dAI Shikun LI Xukun RUI chaofang XIAng Xinlei NIE Key Laboratory of Advanced Manufacturing Intelligent Technology of Ministry of Education Harbin University of Science and TechnologyHarbin 150080China

In recent years,the robot industry has developed rapidly,and researchers and enterprises have begun to pay more attention to this *** are barely familiar with climbing robots,a kind of special ***,from their practical value and scientific research value,climbing robots should studied *** paper analyzes and summarizes the key technologies of climbing robots,introduces various kinds of climbing robots,and examines their advantages and disadvantages to provide a reference for future *** countries have studied climbing robots and made some ***,due to the complexity of climbing robots,their climbing efficiency and accuracy need to be further *** new structure can improve the climbing *** paper analyzes climbing robots such as mechanical arms,magnetic attraction,and *** methods and path planning can improve the accuracy of *** paper involves some control methods,including complex intelligent control methods such as behavior-based robot *** paper also investigates various kinematic planning methods and expounds and summarizes various path planning algorithms,including machine learning and reinforcement learning of artificial intelligence,ant colony algorithm,and other ***,by analyzing the research status of climbing robots at home and abroad,this paper summarizes three important aspects of climbing robots,namely,structural design,control methods,and climbing strategies,elaborates on the achievements and existing problems of these key technologies,and looks forward to the future development trend and research direction of climbing robots.

关键词： climbing robot mechanical structure design control system kinematics planning path planning

Analysis of impacting factors on polarimetric SAR oil spill detection

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2018年第11期37卷 77-87页

作者： SOng Shasha ZHAO chaofang AN Wei LI Xiaofeng WAng Chen College of Information Science and Engineering Ocean University of ChinaQingdao 266100China Post-doctoral Station China Offshore Environmental Services Ltd.Tianjin 300457China Laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266100China National Oceanic and Atmospheric Administration Maryland 20740USA

Polarimetric synthetic aperture radar （SAR） oil spill detection parameters conformity coefficient （μ）, Muller matrix parameters （｜C｜,B0 ）, the eigenvalues of simplified coherency matrix （λnos） and the influence of SAR observing parameters, ocean environment and noise level are investigated. Radarsat-2 data are used to make systematic analysis of polarimetric parameters for different incidences, wind speeds, noise levels and the ocean phenomena （oil slick and look likes）. The influence of the SAR observing parameters, the ocean environment and the noise level on the typical polarimetric SAR parameter conformity coefficient has been analyzed. The results indicate that conformity coefficient cannot be simply used for oil spill detection, which represents the image signal to the noise level to some extent. When the signals are below the noise level for the oil slick and the look likes, the conformity coefficients are negative; while the signals above the noise level corresponds to positive conformity coefficients. For dark patches （low wind and biogenic slick） with the signal below the noise, polarization features such as conformity coefficient cannot separate them with oil slick. For the signal above the noise, the oil slick, the look likes （low wind and biogenic slick） and clean sea all have positive conformity coefficients, among which, the oil slick has the smallest conformity coefficient, the look likes the second, and the clean sea the largest value. For polarimetric SAR data oil spill detection, the noise plays a significant role. So the polafimetric SAR data oil spill detection should be carried out on the basis of noise consideration.

关键词： multi-polarimetric SAR oil spill conformity coefficient noise

Galvanic Corrosion of Magnesium Alloy and Aluminum Alloy by Kelvin Probe

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2016年第1期31卷 204-210页

作者：肖葵 dOng chaofang WEI dan WU Junsheng LI Xiaogang Corrosion and Protetion Center University of Science and Technology Beijing Beijing 100083 China Society Service Center China Association for Science and Technology Beijing 100081 China Ningbo Institute of Material Technology & Engineering Chinese Academy of Sciences Ningbo 315201 China

Galvanic corrosion on samples of AZ91d magnesium alloy coupled with 2A12 aluminum alloy during neutral salt spray test was *** variations of the surface potential were measured using scanning kelvin probe（SKP）.The results showed that galvanic effect on the corrosion of AZ91d magnesium alloy is closely related to the potential difference between the anodic and cathodic *** the initial period,corrosion only occurred in a narrow area at the coupling interface because of the limited distance galvanic ***,the corrosion rate of 2A12 aluminum alloy was accelerated due to its poor stability in strong alkali environment,which was attributed to the strong alkalization caused by the corrosion of AZ91d magnesium *** the increase of the potential of 2A12 aluminum alloy as a result of the continuous covering of corrosion products,the potential difference between the two materials was enlarged,which enhanced the galvanic corrosion.

关键词： magnesium alloy aluminum alloy galvanic corrosion scanning kelvin probe salt spray test

Recrystallization effect on surface passivation of Hastelloy X alloy fabricated by laser powder bed fusion

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第32期163卷 245-258页

作者： Xing He Li Wang decheng Kong Ruixue Li Wei Zhang Kunjie dai Xiaoqing Ni Ketai He chaofang dong Beijing Advanced Innovation Center for Materials Genome Engineering Key Laboratory for Corrosion and Protection(MOE)Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Engineering Research Center of 3d Printing Materials Shanghai Research Institute of MaterialsShanghai 200437China School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China

Post-heat treatment is generally adopted in the additive manufacturing field due to its alleviation of high residual stress and modification of rapid-solidified multilevel heterogeneous microstructure,and the related performance of the heat-treated counterparts calls for a systemic investigation to build a criterion of the heat treatment *** this work,we focus on the heat treatment effects on the recrystallization of the Hastelloy X alloy produced by the laser powder bed fusion(LPBF)method,and the related surface passivation of the heat-treated counterparts is meticulously assessed as *** show that the multilevel heterostructure for LPBF Hastelloy X alloy consists of sub-micro dislocation cell substructures with Cr/Mo elemental segregation,fine columnar grains,and periodically-distributed molten *** heat treatment,partially and fully recrystallized structures for LPBF Hastelloy X alloys were achieved at 1100 and 1200℃for 1 h,***,the as-built LPBF Hastelloy X alloy shows superior corrosion resistance while the heat-treated one(1100℃)exhibits the worst in the borate buffer *** growth of passive film exhibited a highly linear correlation with the nucleation process controlled by diffusion,and high dislocation density and low angle grain boundary decreased the diffusion coefficient of cation vacancies,augmenting the nucleation sites of the passive film and enhancing its growth ***,the micro-galvanic effect resulting from the partially recrystallized microstructure actively facilitated the formation of inhomogeneous porous passive films,leading to the worst corrosion resistance.

关键词： Laser powder bed fusion Hastelloy X Recrystallization Heterogeneous microstructure Passive film