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Effect of friction on corrosion behaviors of AIsI 304 and Cr26Mo1 stainless steels in different solutions

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Journal of Iron and steel Research International 2023年第12期30卷 2541-2556页

作者： Z.x.Dai s.l.Jiang l.K.Ning x.D.xu s.li D.l.Duan shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016LiaoningChina school of Materials science and Engineering University of Science and Technology of ChinaHefei230026AnhuiChina liaoning Key laboratory of Aero-engine Materials Tribology Institute of Metal ResearchChinese Academy of SciencesShenyang110016LiaoningChina Ansteel lIsCO stainless steel Co. Ltd.Guangzhou510760GuangdongChina

The corrosion and tribocorrosion behaviors of AIsI 304 austenitic stainless steel and Cr26Mo1 ultrapure high chromium ferrite stainless steel in 3.5 wt.%NaCl and 0.5 mol/l H2sO4 solutions were *** electrochemical measurement technology was applied to identify electrochemistry behaviors during tribocorrosion tests in *** surface morphologies and compositions of the wear tracks were analyzed by scanning electron microscopy and Raman *** results showed that compositions of stainless steels,corrosive mediums and applied loads have great influence on tribocorrosion behaviors of stainless ***,the corrosion resistance in static state of stainless steels primarily dominates its tribocorrosion behavior;meanwhile,better mechanical properties are in favor of tribocorrosion ***,the corrosion rate is promoted significantly in 3.5%NaCl solution by friction,while the tendency is inconspicuous in 0.5 mol/l H2sO4 *** but not least,passive films on stainless steels can be wiped off by small friction *** the increase in applied load,the effect of friction converts to forming friction oxide film from removing passivation film,so that a critical load exists below which the friction force can promote the corrosion process extremely.

关键词： Tribocorrosion stainless steel/PEEK friction pair Corrosive medium Applied load Microelectrode probe

Microstructure and Mechanical Properties of Dissimilar Double-side Friction stir Welds Between Medium-Thick 6061-T6 Aluminum and Pure Copper Plates

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Acta Metallurgica sinica(English letters) 2022年第12期35卷 2027-2046页

作者： J.x.Tang l.shi C.s.Wu M.x.Wu s.Gao MOE Key lab for liquid-solid structure Evolution and Materials Processing Institute of Materials JoiningShandong UniversityJinan 250061China state Grid Henan Electric Power Research Institute Zhengzhou 450052China school of Mechanical Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan250353China

It is difficult to achieve Al/Cu dissimilar welds with good mechanical properties for medium-thick plates due to the inherent high heat generation rate at the shoulder-workpiece contact interface in conventional friction stir ***,doubleside friction stir welding is innovatively applied to join 12-mm medium-thick 6061-T6 aluminum alloy and pure copper dissimilar plates,and the effect of welding speeds on the joint microstructure and mechanical properties of Al/Cu welds is systematically *** reveals that a sound Al/Cu joint without macroscopic defects can be achieved when the welding speed is lower than 180 mm/min,while a nonuniform relatively thick intermetallic compound(IMC)layer is formed at the Al/Cu interface,resulting in lots of local microcracks within the first-pass weld under the plunging force of the tool during friction stir welding of the second-pass,and seriously deteriorates the mechanical properties of the *** the increase of welding speed to more than 300 mm/min void defects appear in the joint,but the joint properties are still better than the welds performed at low welding speed conditions since a continuous uniform thin IMCs layer is formed at the Al/Cu *** maximum tensile strength and elongation of Al/Cu weld are,respectively,135.11 MPa and 6.06%,which is achieved at the welding speed of 400 mm/*** addition,due to the influence of welding distortion of the first-pass weld,the secondpass weld is more prone to form void defects than the first-pass weld when the same plunge depth is applied on both *** double-side friction stir welding is proved to be a good method for dissimilar welding of medium-thick Al/Cu plates.

关键词： Double-side friction stir welding Medium-thick plate Dissimilar welding Microstructures Intermetallic compounds Mechanical properties

Mechanical properties of gas hydrate-bearing sediments during hydrate dissociation

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Acta Mechanica sinica 2018年第2期34卷 266-274页

作者： x.H.Zhang D.s.luo x.B.lu l.l.liu C.l.liu Institute of Mechanics Chinese Academy of SciencesBeijing 100190China College of Engineering University of Chinese Academy of SciencesBeijing 100049China Key laboratory of Gas Hydrate Ministry of Land and ResourcesQingdao 266071China Qingdao Institute of Marine Geology Qingdao 266071China

The changes in the mechanical properties of gas hydrate-bearing sediments(GHBs) induced by gas hydrate(GH) dissociation are essential to the evaluation of GH exploration and stratum instabilities. Previous studies present substantial mechanical data and constitutive models for GHBs at a given GH saturation under the non-dissociated condition. In this paper, GHBs was formed by the gas saturated method, GH was dissociated by depressurization until the GH saturation reached different dissociation degrees. The stress–strain curves were measured using triaxial tests at a same pore gas pressure and different confining pressures. The results show that the shear strength decreases progressively by 30%–90% of the initial value with GH dissociation, and the modulus decreases by 50% –75%. simplified relationships for the modulus, cohesion, and internal friction angle with GH dissociated saturation were presented.

关键词： Gas hydrate-bearing sediments Dissociation Mechanical properties shear strength Triaxial test

Getting physical with medical education:Exercise based virtual anatomy review classes for medical students

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World Journal of Methodology 2025年第1期15卷 20-25页

作者： Nadeesha R samarasinghe Taniya s Nagpal Michele l Barbeau Charys M Martin Division of General surgery Faculty of MedicineUniversity of British ColumbiaVancouver V6T 1Z3BCCanada Faculty of Kinesiology Sport and RecreationUniversity of AlbertaEdmonton T6G 2R3ABCanada Anatomy and Cell Biology University of Western OntarioLondon N6A 3K7ONCanada Department of Anatomy and Cell Biology Schulich School of Medicine and DentistryThe University of Western OntarioLondon N6A 3K7ONCanada

The benefits of regular physical activity are well ***,few studies have examined the effectiveness of integrating physical activity(PA)into curricula within a post-secondary *** investigate the incorporation of PA into medical curriculum,we developed a series of optional exercise-based review sessions designed to reinforce musculoskeletal(MsK)anatomy course *** synchronous sessions were co-taught by a group fitness instructor and an anatomy *** fitness instructor would lead students through both strength and yoga style exercises,while the anatomy instructor asked questions about relevant anatomical structures related to course material previously *** the sessions,participants were asked to evaluate the classes on their self-reported exam preparedness in improving MsK anatomy knowledge,PA levels,and mental *** participants completed surveys;a majority agreed that the classes increased understanding of MsK concepts(90.0%)and activity levels(97.7%).Many(70.0%)felt that the classes helped reduce *** majority of respondents(90.0%)agreed that the classes contributed to increased feelings of social ***,medical students saw benefit in PA based interventions to supplement MsK course *** with increasing activity levels and promoting health behaviours,integrating PA into medical curriculum may improve comprehension of learning material,alleviate stress and foster social connectivity among medical students.

关键词： Medical education Musculoskeletal Anatomy Exercise Online learning

structure evolution of the Fe_(3)C/Fe interface mediated by cementite decomposition in cold-deformed pearlitic steel wires

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Journal of Materials science & Technology 2022年第6期101卷 28-36页

作者： Y.T.Zhou x.H.shao s.J.Zheng x.l.Ma shenyang National laboratory for Materials science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Tianjin Key laboratory of Materials laminating Fabrication and Interface Control Technology School of Materials Science and EngineeringHebei University of TechnologyTianjin 300130China

Cold-drawn pearlitic steel wire is irreplaceably used in industry owing to its outstanding mechanical property which is dominated by the cementite/ferrite(Fe_(3)C/Fe) interfaces in the material. However, the fine structures of the Fe3C/Fe interfaces in the deformed wires are less known to date. In this work, transmission electron microscopic investigation was performed on the atomic structures of the interfaces with the Isaichev orientation relationship(OR) in the wires with progressive deformation strains. In addition to the effect of the dislocation/interface interactions, this work revealed that the deformation-induced partial decomposition of cementite plays an important role in the interface reconstruction during deformation. The interfacial carbon vacancies generated by cementite decomposition and particularly, the amorphization of cementite layers in the sample with ε > 1 could effectively annihilated the interfacial dislocations and consequently relaxed the interfacial stress. The correlations between the interface structure changes and the mechanical properties of the wires were discussed.

关键词： Pearlitic steel Cementite decomposition Interface structure Deformation Transmission electron microscopy

Mechanism of wavy vortex and sign laws in flow past a bluff body:vortex-induced vortex

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Acta Mechanica sinica 2019年第1期35卷 1-14,I0001页

作者： l.M.lin s.Y.shi x.F.Zhong Y.x.Wu Key laboratory for Mechanics in Fluid solid Coupling systems Institute of MechanicsChinese Academy of SciencesBeijing 100190China school of Engineering sciences University of Chinese Academy of SciencesBeijing 100049China

As reported in a previous work by lin et al.(Acta Meeh sin, 2018. https://***/10.1007/s 10409-018-0758-z), an interesting phenomenon was discovered based on the analysis of wavy vortex and vorticity distribution in the shear layers and near wake of a peak-perforated conic shroud, and two sign laws were summarized. In the present paper, the theory of a vortex-induced vortex is introduced to explore mechanisms in a wavy vortex and applicable sign laws for uniform and incompressible flow past a fixed bluff body. Based on the analysis of the nearest-wall How, two vortex-induced models for streamwise and vertical vortex pairs, respectively, are proposed under two boundary cases, denoting the induced vorticity introduced or distributed on and near the walls. As a result, the first sign law, for only streamwise and vertical components of vorticity, and the second sign law, for three components of vorticity, are obtained under their own particular conditions. The first sign law reveals the intrinsic physical relationship between streamwise and vertical vorticities, independent of the distribution of spanwise vortices in the whole flow field. It is also confirmed that the spanwise vortices, as well as the shear layers and wake width, distributed wavily across the span, are attributed to the introduced streamwise or vertical vortices. The two sign laws for vorticity are independent of the disturbed spanwise wavelength and the Reynolds number. Through the analysis of flow past the conic shroud, the two sign laws are successfully used to summarize typical spacial distributions of vorticity in three flow regions: on and near the front cylinder surfaces, the separated shear layers and the near wake.

关键词： Wavy vortex sign law Vortex-induced vortex Wake Bluff body

Cadmium sulfide cage photocatalysis coupled electroactive biofilm for synergistic promotion of tetracycline degradation and electricity production

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Journal of Materials science & Technology 2023年第35期166卷 86-97页

作者： Z.s.Yuan J.x.Zou x.l.Zhao J.Y.shi C.s.Guo M.Yan school of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China

Tetracycline(TC)as a common broad-spectrum antibiotic,has been frequently detected in soil and sur-face *** becomes a great threat to the ecological ***,a device of photocatalysis as-sisted microbial fuel cell(photo-MFC)was constructed for TC degradation and energy *** this photo-MFC,cadmium sulfide(Cds)cage photocatalysis can degrade most of TC in a short *** the Co_(3)O_(4)@C-CC(carbonization and calcination of the ZIF-67 precursor in-situ grown on the carbon cloth(CC))bioanode degrades the rest of TC as well as the photocatalytic products,thus improving the *** co-existence of photocatalysis with bioanode changes the microbial community structure of the *** dominant phylum is Geobacter(60.2%)in normal MFC while that in photo-MFC are Pro-teobacteria(43.5%)and Geobacter(33.2%).Therefore,the synergistic effect of photocatalytic degradation and biodegradation achieves a chemical oxygen demand(COD)removal of 98.6%,which is higher than that of normal MFC(77.6%)or single Cds cage photocatalysis(23.8%).In addition,the photogenerated electrons can be transferred to the cathode,which reduces their combination with holes and increases the electricity generation of MFC,achieving a maximum power density of 3.37 W/m^(2).After degradation,the effluent with 200 mg l^(−1) TC exhibits no visible ***,electrochemical test,finite-difference time-domain(FDTD),density functional theory(DFT)calculation and the free radical trapping experiments verify the possible mechanisms of photocatalytic degradation in this *** strat-egy paves a new way for low energy consumption removal and energy recovery of organic pollutants.

关键词： Photo-MFC Cds cage Tetracycline degradation Mineralization Electricity production

INFlUENCING FACTORs FOR OBTAINING UlTRAFINE AUsTENITE GRAINs WITH INITIAl MICROsTRUCTURE OF WARM-ROllED FERRITE/PEARlITE

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Acta Metallurgica sinica(English letters) 2008年第6期21卷 391-398页

作者： s.J. Yao l.x. Du x.H. liu G.D. Wang state Key laboratory ofRolling and Automation Northeastern University Shenyang 110004 China

Three warm-rolled ferrite/pearlite microstructures were prepared by rolling at 500℃, and the austenitizing characteristics were discussed in conjunction with deformation during the heating stage. The results indicated that the final austenite grain size was sensitive to the deformation direction of the initial warm-rolled microstructure. The transient microstructure at a given temperature was the most important influencing factor on the austenitizing characteristic combined with deformation. Moreover, the hot-rolled mierostructure also had to be prepared in an optimal state because of its direct effect on the warm-rolled microstructure.

关键词： Warm-rolled ferrite/pearlite Austenite Deformation Recrystallization

DIMENsIONAl INsTABIlITY OF lD31 Al AllOY WElDMENTs AT ROOM TEMPERATURE AND AFTER THERMAl CYClEs

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Acta Metallurgica sinica(English letters) 2004年第1期17卷 64-70页

作者： x.s.liu H.Y.Fang W.l.xu x.T.Tian x.D.sun National key laboratory of Advanced Welding Production and Technology Harbin Institute of Technology Harbin 150001ChinaNational key Laboratory of Advanced Welding Production and Technology Harbin Institute of Technology Harbin 150001ChinaNational key Laboratory of Advanced Welding Production and Technology Harbin Institute of Technology Harbin 150001ChinaNational key Laboratory of Advanced Welding Production and Technology Harbin Institute of Technology Harbin 150001ChinaHarbin First Mechanical Production Factory Harbin 150080China

The unstable dimensional distortion of lD31 aluminum alloy weldments at room temperature and after thermal cycles was studied by use of light interference and CMM(three-coordinate measuring machines). At the same time, distortion mechanism was analyzed from the viewpoint of mechanics and micro structure. Experimental results show that there exists obvious difference of unstable dimensional distortion between lD31 welded specimens under two conditions mentioned above. Under room temperature, dimensional variation of welded specimens will decrease gradually and finally tends to be stable during 200h after welding. The relative elongation of welded specimen is 3.0×10-5; After thermal cycles, distortion of welded specimen is much larger than that at room temperature. After 11 thermal cycles, the dimension will tend to be stable. Dimensional unstable distortion of weldments mainly results from temperature condition, microstructure variation and relaxation of welding residual stress.

关键词： lD31 aluminum alloy light interference room temperature and thermal cycles dimensional instability