This work investigated the original microstructure of cold-worked alumina-forming austenitic steel,along with its precipitation and dissolution corrosion behaviors in lead-bismuth eutectic with 10-8 wt.%oxygen at 600...This work investigated the original microstructure of cold-worked alumina-forming austenitic steel,along with its precipitation and dissolution corrosion behaviors in lead-bismuth eutectic with 10-8 wt.%oxygen at 600℃,using solution-annealed steel for comparison.Anomalously,cold-worked steel presented milder corrosion compared to solution-annealed steel,with average corrosion depths of 314.3 and 401.0μm after 1700 h exposure.Cold working-induced de-twinning transformed the annealing twin boundaries into normal high-angle grain boundaries(NGBs),increasing NGBs proportion from 36%to 89%.The increased NGBs provided more nucleation sites for intergranular barriers composed of alternate NiAl and M23C6 precipitates,thus better obstructing the dissolution attack.展开更多
The study investigated the oxidation behavior of T91 steel modified with Al(T91-Al)and Si(T91-Si)in lead-bismuth eutectic(LBE)at 450℃under oxygen-saturated conditions(10^(−7)-10^(−8)wt.%)and oxygen-controlled conditi...The study investigated the oxidation behavior of T91 steel modified with Al(T91-Al)and Si(T91-Si)in lead-bismuth eutectic(LBE)at 450℃under oxygen-saturated conditions(10^(−7)-10^(−8)wt.%)and oxygen-controlled conditions(3.2×10^(−4)wt.%).Advanced characterization techniques were employed to under-stand the thermodynamic and kinetic mechanisms of enhanced oxidation properties of the modified T91 steel.The results indicate that the oxidation resistance of the materials follows this order:T91<T91-Al<T91-Si.Noteworthy,the oxidation resistance of T91-Si material exhibited minimal correlation with dissolved oxygen.Under oxygen-controlled conditions,the oxide film of T91 and T91-Al was attacked and broken by LBE,with the former eventually peeling off.In contrast,both materials showed significant ox-ide film thickening,except T91-Si under oxygen-saturated conditions.The addition of Al improved the quality of the inner oxide film on T91-Al by generating Al_(2)O_(3),thereby slowing down the diffusion of Fe from the matrix and enhancing oxidation resistance.Conversely,Si actively participated in the oxidation process of T91-Si,slowing down the diffusion of Fe,and facilitating the diffusion of Cr,thereby strength-ening the oxide film protection.Consequently,the oxide thickness of T91-Si material was only 24%of T91 and 35%of T91-Al under saturated oxygen conditions.展开更多
In this work,tensile mechanical behavior of 316L steels fabricated by three different processing methods(casting,powder extrusion printing(PEP)and laser powder bed fusion(LPBF))was studied in the presence of liquid le...In this work,tensile mechanical behavior of 316L steels fabricated by three different processing methods(casting,powder extrusion printing(PEP)and laser powder bed fusion(LPBF))was studied in the presence of liquid lead-bismuth eutectic(LBE)and air at 350℃.The results show that all three steels tested in LBE are not subjected to evident degradation of tensile elongation to failure and strength compared to those tested in air,suggesting that LME does not occur regardless of the processing methods.The LPBF 316L steel exhibits the highest yield strength(420-435 MPa),followed by casting 316 L(~242 MPa)and PEP 316L(146-165 MPa).Ultimate tensile strength of three steels is comparable and ranges from 427 to 485 MPa.The PEP and casting 316L steels have similar total elongation to failure(i.e.,40.0%-43.8%),whereas this property decreases markedly to 18.6%-19.5% for the LPBF 316 L steel.The superior strength and relatively low ductility of the LPBF 316L steel can be attributed to nanosized dislocations trapped at cell structures which can produce a remarkable strengthening effect to the steel matrix.By contrast,due to massive residual micropores,the PEP 316L steel has the lowest strength.展开更多
In lead-cooled fast reactor(LFR)systems,the liquid lead-bismuth eutectic(LBE)coolant provides a cor-rosive environment that damages the steel components during high-temperature operation.This study investigated the mi...In lead-cooled fast reactor(LFR)systems,the liquid lead-bismuth eutectic(LBE)coolant provides a cor-rosive environment that damages the steel components during high-temperature operation.This study investigated the microstructural deterioration of 9Cr ferritic/martensitic(F/M)steel under thermal aging at 550℃for 2,000,10,000,or 20,000 h and its effect on oxidation corrosion in an LBE environment using multiscale characterization techniques.The results indicated that the thickness of the internal oxidation zone(IOZ)increased significantly with extended thermal aging,whereas that of the spinel layer remained relatively constant.The abundant subgrain boundaries that emerged during extensive thermal aging facil-itated Fe diffusion,and the enlarged Cr-rich M23C6 carbides contributed to the formation of preferential oxidation regions,accelerating IOZ layer growth.The spinel layer formed from the IOZ was influenced by microstructural defects within the IOZ.A theoretical model describing the accelerated oxide layer growth due to thermal aging was developed.These findings support the advancement of LFR technology.展开更多
The Fe_(949.7)Cr_(18)Mn_(1.9)Mo_(7.4)W_(1.6)B_(15.2)C_(3.8)Si_(2) amorphous coating was deposited on T91 steel substrate by using the high-velocity oxygen fuel(HVOF)spray technique to enhance the corrosion resistance ...The Fe_(949.7)Cr_(18)Mn_(1.9)Mo_(7.4)W_(1.6)B_(15.2)C_(3.8)Si_(2) amorphous coating was deposited on T91 steel substrate by using the high-velocity oxygen fuel(HVOF)spray technique to enhance the corrosion resistance of T91 stainless steel in liquid lead-bismuth eutectic(LBE).The corrosion behavior of the T91 steel and coating exposed to oxygen-saturated LBE at 400℃ for 500 h was investigated.Results showed that the T91 substrate was severely corroded and covered by a homogeneously distributed dual-layer oxide on the interface contacted to LBE,consisting of an outer magnetite layer and an inner Fe-Cr spinel layer.Meanwhile,the amorphous coating with a high glass transition temperature(Tg=550℃)and crystallization temperature(T_(x)=600℃)exhibited dramatically enhanced thermal stability and corrosion resistance.No visible LBE penetration was observed,although small amounts of Fe_(3)O_(4),Cr_(2)O_(3),and PbO were found on the coating surface.In addition,the amorphicity and interface bonding of the coating layer remained unchanged after the LBE corrosion.The Fe-based amorphous coating can act as a stable barrier layer in liquid LBE and have great application potential for long-term service in LBE-cooled fast reactors.展开更多
The tensile tests of T91 and T91Si steels at 200-450℃in air and at 350℃in oxygen-depleted liquid lead-bismuth eutectic(LBE)environment with strain rate of 1×10^(-5)-5×10^(-3)were performed.Results show tha...The tensile tests of T91 and T91Si steels at 200-450℃in air and at 350℃in oxygen-depleted liquid lead-bismuth eutectic(LBE)environment with strain rate of 1×10^(-5)-5×10^(-3)were performed.Results show that the activation energy of T91 steel is 103.45-246.76 kJ/mol and that of T91Si steel is 146.98-172.11 kJ/mol when Portevin-Le Chatelie(PLC)phenomenon occurs.The elongation reduction of T91 steel at 350℃is not specific to LBE environment,whereas the presence of LBE promotes crack initiation and propagation and affects the elongation of the material in the necking stage.With Si addition,the elongation,especially the uniform elongation at 350℃in LBE environment,improves,and the tendency toward crack propagation in T91 steel after slow tensile necking is reduced.The PLC phenomenon can be seen in both T91 and T91Si steels at high temperatures owing to the dynamic strain aging(DSA).The temperature ranges are different when DSA occurs,with 300-350℃and 250-350℃for T91 and T91Si steels,respectively.展开更多
Classical molecular dynamics simulations with global neural network machine learning potential are used to study early stage oxidation and dissolution behaviors of bcc Fe surfaces contacting with stagnant oxygen disso...Classical molecular dynamics simulations with global neural network machine learning potential are used to study early stage oxidation and dissolution behaviors of bcc Fe surfaces contacting with stagnant oxygen dissolved liquid leadbismuth eutectic(LBE-O).Both static and dynamic simulation results indicate that the early stage oxidation and dissolution behaviors of bcc Fe show strong orientation dependence under the liquid LBE environments,which may explain the experimental observations of uneven interface between iron-based materials and liquid LBE.Our investigations show that it is the delicate balance between the oxide growth and metal dissolution that leads to the observed corrosion anisotropy for bcc Fe contacting with liquid LBE-O.展开更多
Studies of synergetic irradiation effects and liquid lead-bismuth eutectic(LBE) corrosion/embrittlement effects on ferritic/martensitic(F/M) steels are of great importance for developing high power spallation neutron ...Studies of synergetic irradiation effects and liquid lead-bismuth eutectic(LBE) corrosion/embrittlement effects on ferritic/martensitic(F/M) steels are of great importance for developing high power spallation neutron targets(>1 M W) such as the European Spallation Source(ESS) and Accelerator Driven System(ADS) facilities that can be used for transmuting long-lifetime radioactive wastes. Liquid LBE(45Pb-55Bi,in terms of mass fraction) has been selected as the candidate target material in high power spallation neutron targets due to its favourable thermal,physical & chemical properties,and to its high spallation neutron yield. 9Cr F/M steels such as T91(9Cr1M oVNb,in terms of mass fraction) have been chosen as the structural material for the targets due to their good mechanical properties and good resistance to irradiation induced swelling in fission neutron irradiation environments. For developing high power spallation neutron targets,behaviors of F/M steels in spallation neutron target irradiation environments and LBE corrosion/embrittlement effects have been extensively studied. However,many open questions have not been answered. The aim of this paper is to describe the present research situation on this topic. The obtained experimental data about LBE embrittlement effects on F/M steels is summarized and the influence of different parameters involved is analyzed to understand the influence effect on LBE embrittlement effect of F/M s.展开更多
The cavitation erosion of weld joint and base metal of China low activation martensitic（CLAM）steel in liquid lead-bismuth eutectic alloy（LBE）at 550°C was investigated to simulate the cavitation erosion of the...The cavitation erosion of weld joint and base metal of China low activation martensitic（CLAM）steel in liquid lead-bismuth eutectic alloy（LBE）at 550°C was investigated to simulate the cavitation erosion of the first wall and the nuclear main pump impeller in the accelerator driven sub-critical system（ADS）.A suit of ultrasonic cavitation facility was self-designed to study the cavitation erosion.By studying the surface micro topography,roughness and mean pit depth of the tested specimens,it was found that some crater clusters and large scale cracks appeared on the tested specimen surface after the formation of numerous single craters,and the base metal exhibited much better cavitation erosion resistance than the weld bead due to the difference in their mechanical properties and microstructures.In addition,by comparing the results of static corrosion and cavitation erosion,it could be concluded that the cavitation erosion and the dissolution and oxidation corrosion in liquid LBE would accelerate mutually.展开更多
This study investigates the impact of silicon(Si)on the corrosion resistance and post-corrosion toughness of ferrite/martensitic(F/M)steels in a liquid lead-bismuth eutectic(LBE)environment.Corrosion tests were perfor...This study investigates the impact of silicon(Si)on the corrosion resistance and post-corrosion toughness of ferrite/martensitic(F/M)steels in a liquid lead-bismuth eutectic(LBE)environment.Corrosion tests were performed on HT-9 and EP-823(1.17 wt%Si)steels at 550℃for 1000 h under oxygen-controlled conditions.The resulting oxide layer consisted of an outer magnetite layer,a spinel layer and an inner oxide zone(IOZ).A Si-rich oxide layer was identified within the spinel and IOZ layers of EP-823,which slowed the growth rate of the oxide layer,enhanced antioxidant performance,and inhibited dissolution corrosion by the LBE.Post-corrosion mechanical properties were evaluated using a small punch test.Results showed a significant reduction in HT-9's toughness within 240 h of corrosion,while EP-823 exhibited increased brittleness after 500 h due to Si-promoted carbide and Laves phase precipitation,significantly reducing its toughness.展开更多
To better understand the stainless steel corrosion behavior in lead-bismuth eutectic flow,the iron mass transfer phenomenon on roughened walls under various pipe flow conditions were numerically investigated.Low Reyno...To better understand the stainless steel corrosion behavior in lead-bismuth eutectic flow,the iron mass transfer phenomenon on roughened walls under various pipe flow conditions were numerically investigated.Low Reynolds number k-εmodel was applied in CFD simulation of mass transfer,in which the Reynolds number covers from 5×10^(3) to 1×10^(5).展开更多
The performance degradation of structural materials caused by corrosion of the coolant lead-bismuth eutectic(LBE)alloy has become one of the most serious challenges facing the construction of lead-cooled fast reactors...The performance degradation of structural materials caused by corrosion of the coolant lead-bismuth eutectic(LBE)alloy has become one of the most serious challenges facing the construction of lead-cooled fast reactors^([13]).Grain re nement is a way to improve the corrosion resistance of steels[4-8].However,its e ect on the LBE corrosion behavior of steels is still very little studied.In this study.展开更多
Lead-bismuth eutectic(LBE)is a promising candidate material of core coolants and high-power spallation targets of accelerator driven system(ADS)for transmutation of radioactive wastes and of coolants of fast reactors(...Lead-bismuth eutectic(LBE)is a promising candidate material of core coolants and high-power spallation targets of accelerator driven system(ADS)for transmutation of radioactive wastes and of coolants of fast reactors(FRs).展开更多
The Lead-cooled Fast Reactor(LFR)is one of the fourth-generation nuclear energy systems with excellent development prospects.Liquid lead-bismuth eutectic(LBE)(44.5wt.%Pb+55.5wt.%Bi)appears to be a promising candidate ...The Lead-cooled Fast Reactor(LFR)is one of the fourth-generation nuclear energy systems with excellent development prospects.Liquid lead-bismuth eutectic(LBE)(44.5wt.%Pb+55.5wt.%Bi)appears to be a promising candidate as a coolant for LFR due to its low melting point of 397 K,fast heat removing from the target,good neutron yield and low vapour pressure.However,the liquid LBE is corrosive to both austenitic steels and ferriticmartensitic steels.展开更多
Investigations on entropy generation and thermal irreversibility analysis are conducted for liquid lead-bismuth eutectic(LBE)in an annular pipe.To find better performance in convective heat transfer,the computational ...Investigations on entropy generation and thermal irreversibility analysis are conducted for liquid lead-bismuth eutectic(LBE)in an annular pipe.To find better performance in convective heat transfer,the computational fluid dynamics(CFD)code based on the finite volume method(FVM)is adopted to solve this problem.The elevated temperature LBE flows in the annular pipe,and four types of heat flux,including constant,linear increase and decrease,and parabolic distributions are imposed at the inside wall of the annular pipe.The investigations are conducted for the specific average heat input of 200 kW/m^(2),and the different Peclet number Pe is set from 1200 to 3200.The SST k-ωturbulent model and Cheng-Tak Prt model are adopted.The mesh independence validation and models verification are also conducted and the maximum Nu error is 5.43%compared with previous experimental correlations.The results from the local and system scales,respectively,including volumetric dimensionless entropy generation,Ns,Be,and Ep,are discussed.The results indicate that the viscous friction and heat transfer caused by entropy generation can be found in the viscous sub-layer and buffer layer respectively.Heat transfer is the primary factor that leads to irreversible losses.Besides,the results show that the best thermodynamic performance occurs under parabolic distributed heat flux in the research scope.展开更多
Dual-phase heterogeneous structures confer eutectic high-entropy alloy(EHEA)with excellent strength-ductility synergy under quasi-static tensile loading.However,it is questionable whether the EHEAs pos-sess equally go...Dual-phase heterogeneous structures confer eutectic high-entropy alloy(EHEA)with excellent strength-ductility synergy under quasi-static tensile loading.However,it is questionable whether the EHEAs pos-sess equally good impact toughness because the phase interfaces are vulnerable to crack initiation.This work aimed to study the Charpy impact toughness and fracture behavior of AlCoCrFeNi_(2.1) EHEA.The results indicate that while maintaining high tensile strength and ductility,the AlCoCrFeNi_(2.1) EHEA also shows a satisfactory impact toughness of 25.86 J/cm^(2),superior to most other dual-phase alloys like TC4 titanium alloy or DP steel.Fractography analysis reveals characteristic regions of the fracture surface,which suggests energy absorption mechanisms primarily through ductile dimples,flat cleavage facets,secondary cracks,and microvoids,corresponding to a ductile-brittle mixed fracture mode.Detailed obser-vations of the deformed microstructure through TEM and EBSD demonstrate that FCC(L1_(2))and BCC(B2)phases underwent concurrent tearing along their phase boundaries,indicating a crucial influence of phase boundaries over crack initiation and propagation.The FCC(L1_(2))phase bore almost all plastic deformation of the sample through dislocation slip,whereas the BCC(B2)phase underwent a rapid shearing but almost no dislocation slip.Crack initiation under impact loading typically starts at the FCC(L1_(2))/BCC(B2)inter-face before propagating through the BCC(B2)phase.Additionally,this work further examines the effect of sample size and notch shape on the impact toughness of AlCoCrFeNi_(2.1) EHEA.A comparative analysis of the mechanical behavior under static and impact loading was also conducted,highlighting differences and connections in stress distribution and fracture surface morphology.The study offers valuable insights into the mechanical response and fracture behavior of AlCoCrFeNi_(2.1) EHEA under impact loading,provid-ing crucial information for its potential industrial applications.展开更多
The deterioration of aqueous zinc-ion batteries(AZIBs)is confronted with challenges such as unregulated Zn^(2+)diffusion,dendrite growth and severe decay in battery performance under harsh environments.Here,a design c...The deterioration of aqueous zinc-ion batteries(AZIBs)is confronted with challenges such as unregulated Zn^(2+)diffusion,dendrite growth and severe decay in battery performance under harsh environments.Here,a design concept of eutectic electrolyte is presented by mixing long chain polymer molecules,polyethylene glycol dimethyl ether(PEGDME),with H_(2)O based on zinc trifluoromethyl sulfonate(Zn(OTf)2),to reconstruct the Zn^(2+)solvated structure and in situ modified the adsorption layer on Zn electrode surface.Molecular dynamics simulations(MD),density functional theory(DFT)calculations were combined with experiment to prove that the long-chain polymer-PEGDME could effectively reduce side reactions,change the solvation structure of the electrolyte and priority absorbed on Zn(002),achieving a stable dendrite-free Zn anode.Due to the comprehensive regulation of solvation structure and zinc deposition by PEGDME,it can stably cycle for over 3200 h at room temperature at 0.5 mA/cm^(2)and 0.5 mAh/cm^(2).Even at high-temperature environments of 60℃,it can steadily work for more than 800 cycles(1600 h).Improved cyclic stability and rate performance of aqueous Zn‖VO_(2)batteries in modified electrolyte were also achieved at both room and high temperatures.Beyond that,the demonstration of stable and high-capacity Zn‖VO_(2)pouch cells also implies its practical application.展开更多
Gels and conductive polymer composites,including hydrogen bonds(HBs),have emerged as promising materials for electro-magnetic wave(EMW)absorption across various applications.However,the relationship between conduction...Gels and conductive polymer composites,including hydrogen bonds(HBs),have emerged as promising materials for electro-magnetic wave(EMW)absorption across various applications.However,the relationship between conduction loss in EMW-absorbing materials and charge transfer in HB remains to be fully understood.In this study,we developed a series of deep eutectic gels to fine-tune the quantity of HB by adjusting the molar ratio of choline chloride(ChCl)and ethylene glycol(EG).Owing to the unique properties of deep eutectic gels,the effects of magnetic loss and polarization loss on EMW attenuation can be disregarded.Our results indicate that the quantity of HB initially increases and then decreases with the introduction of EG,with HB-induced conductive loss following similar pat-terns.At a ChCl and EG molar ratio of 2.4,the gel labeled G22-CE2.4 exhibited the best EMW absorption performance,characterized by an effective absorption bandwidth of 8.50 GHz and a thickness of 2.54 mm.This superior performance is attributed to the synergistic ef-fects of excellent conductive loss and impedance matching generated by the optimal number of HB.This work elucidates the role of HB in dielectric loss for the first time and provides valuable insights into the optimal design of supramolecular polymer absorbers.展开更多
As a 3D printing method,laser powder bed fusion(LPBF)technology has been extensively proven to offer significant advantages in fabricating complex structured specimens,achieving ultra-fine microstructures,and enhancin...As a 3D printing method,laser powder bed fusion(LPBF)technology has been extensively proven to offer significant advantages in fabricating complex structured specimens,achieving ultra-fine microstructures,and enhancing performances.In the domain of manufacturing melt-grown oxide ceramics,it encounters substantial challenges in suppressing crack defects during the rapid solidification process.The strategic integration of high entropy alloys(HEA),leveraging the significant ductility and toughness into ceramic powders represents a major innovation in overcoming the obstacles.The ingenious doping of HEA parti-cles preserves the eutectic microstructures of the Al_(2)O_(3)/GdAlO_(3)(GAP)/ZrO_(2)ceramic composite.The high damage tolerance of the HEA alloy under high strain rates enables the absorption of crack energy and alleviation of internal stresses during LPBF,effectively reducing crack initiation and growth.Due to in-creased curvature forces and intense Marangoni convection at the top of the molt pool,particle collision intensifies,leading to the tendency of HEA particles to agglomerate at the upper part of the molt pool.However,this phenomenon can be effectively alleviated in the remelting process of subsequent layer de-position.Furthermore,a portion of the HEA particles partially dissolves and sinks into the molten pool,acting as heterogeneous nucleation particles,inducing the formation of equiaxed eutectic and leading pri-mary phase nucleation.Some HEA particles diffuse into the lamellar ternary eutectic structures,further promoting the refinement of eutectic microstructures due to increased undercooling.The innovative dop-ing of HEA particles has effectively facilitated the fabrication of turbine-structured,conical,and cylindrical ternary eutectic ceramic composite specimens with diameters of about 70 mm,demonstrating significant developmental potential in the field of ceramic composite manufacturing.展开更多
Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and ...Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.展开更多
基金supported by the Nuclear Technology R&D Program.
文摘This work investigated the original microstructure of cold-worked alumina-forming austenitic steel,along with its precipitation and dissolution corrosion behaviors in lead-bismuth eutectic with 10-8 wt.%oxygen at 600℃,using solution-annealed steel for comparison.Anomalously,cold-worked steel presented milder corrosion compared to solution-annealed steel,with average corrosion depths of 314.3 and 401.0μm after 1700 h exposure.Cold working-induced de-twinning transformed the annealing twin boundaries into normal high-angle grain boundaries(NGBs),increasing NGBs proportion from 36%to 89%.The increased NGBs provided more nucleation sites for intergranular barriers composed of alternate NiAl and M23C6 precipitates,thus better obstructing the dissolution attack.
基金financial support from the National Key R&D Program of China(No.2020YFA0405901)the National Natural Science Foundation of China(Nos.52375155 and 51875398).
文摘The study investigated the oxidation behavior of T91 steel modified with Al(T91-Al)and Si(T91-Si)in lead-bismuth eutectic(LBE)at 450℃under oxygen-saturated conditions(10^(−7)-10^(−8)wt.%)and oxygen-controlled conditions(3.2×10^(−4)wt.%).Advanced characterization techniques were employed to under-stand the thermodynamic and kinetic mechanisms of enhanced oxidation properties of the modified T91 steel.The results indicate that the oxidation resistance of the materials follows this order:T91<T91-Al<T91-Si.Noteworthy,the oxidation resistance of T91-Si material exhibited minimal correlation with dissolved oxygen.Under oxygen-controlled conditions,the oxide film of T91 and T91-Al was attacked and broken by LBE,with the former eventually peeling off.In contrast,both materials showed significant ox-ide film thickening,except T91-Si under oxygen-saturated conditions.The addition of Al improved the quality of the inner oxide film on T91-Al by generating Al_(2)O_(3),thereby slowing down the diffusion of Fe from the matrix and enhancing oxidation resistance.Conversely,Si actively participated in the oxidation process of T91-Si,slowing down the diffusion of Fe,and facilitating the diffusion of Cr,thereby strength-ening the oxide film protection.Consequently,the oxide thickness of T91-Si material was only 24%of T91 and 35%of T91-Al under saturated oxygen conditions.
基金Project(2024YFB4608600)supported by the National Key Research and Development Program of ChinaProjects(52271063,U21B2066,U24B2024)supported by the National Natural Science Foundation of China+3 种基金Project(JSGG20210713091539014)supported by the Shenzhen Science and Technology Innovation Commission Key Technical Project,ChinaProject(HNGD2025040)supported by the Overseas High-Level Talents Introduction of Henan Province,ChinaProject(240621041)supported by the Fundamental Research Funds of Henan Academy of Sciences,ChinaProject(20231120233925001)supported by Stabilization Support Program for Higher Education Institutions of Shenzhen,China。
文摘In this work,tensile mechanical behavior of 316L steels fabricated by three different processing methods(casting,powder extrusion printing(PEP)and laser powder bed fusion(LPBF))was studied in the presence of liquid lead-bismuth eutectic(LBE)and air at 350℃.The results show that all three steels tested in LBE are not subjected to evident degradation of tensile elongation to failure and strength compared to those tested in air,suggesting that LME does not occur regardless of the processing methods.The LPBF 316L steel exhibits the highest yield strength(420-435 MPa),followed by casting 316 L(~242 MPa)and PEP 316L(146-165 MPa).Ultimate tensile strength of three steels is comparable and ranges from 427 to 485 MPa.The PEP and casting 316L steels have similar total elongation to failure(i.e.,40.0%-43.8%),whereas this property decreases markedly to 18.6%-19.5% for the LPBF 316 L steel.The superior strength and relatively low ductility of the LPBF 316L steel can be attributed to nanosized dislocations trapped at cell structures which can produce a remarkable strengthening effect to the steel matrix.By contrast,due to massive residual micropores,the PEP 316L steel has the lowest strength.
基金supported by the Natural Science Foundation of Shandong Province with grant No.ZR2023ME196the Science and Technology Support Plan for Young Innovation of Colleges and Universities of Shandong Province with grant No.2022KJ273+1 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences with grant No.2017486the Patent Navigation Project of Shandong Province with grant No.D202327.
文摘In lead-cooled fast reactor(LFR)systems,the liquid lead-bismuth eutectic(LBE)coolant provides a cor-rosive environment that damages the steel components during high-temperature operation.This study investigated the microstructural deterioration of 9Cr ferritic/martensitic(F/M)steel under thermal aging at 550℃for 2,000,10,000,or 20,000 h and its effect on oxidation corrosion in an LBE environment using multiscale characterization techniques.The results indicated that the thickness of the internal oxidation zone(IOZ)increased significantly with extended thermal aging,whereas that of the spinel layer remained relatively constant.The abundant subgrain boundaries that emerged during extensive thermal aging facil-itated Fe diffusion,and the enlarged Cr-rich M23C6 carbides contributed to the formation of preferential oxidation regions,accelerating IOZ layer growth.The spinel layer formed from the IOZ was influenced by microstructural defects within the IOZ.A theoretical model describing the accelerated oxide layer growth due to thermal aging was developed.These findings support the advancement of LFR technology.
基金financially supported by the National Natural Science Foundation of China (Nos. 52061135207, 51871016, 51921001, 5197011039, 5197011018, and U20b200318)the China Nuclear Power Technology Research Institute Co., Ltd
文摘The Fe_(949.7)Cr_(18)Mn_(1.9)Mo_(7.4)W_(1.6)B_(15.2)C_(3.8)Si_(2) amorphous coating was deposited on T91 steel substrate by using the high-velocity oxygen fuel(HVOF)spray technique to enhance the corrosion resistance of T91 stainless steel in liquid lead-bismuth eutectic(LBE).The corrosion behavior of the T91 steel and coating exposed to oxygen-saturated LBE at 400℃ for 500 h was investigated.Results showed that the T91 substrate was severely corroded and covered by a homogeneously distributed dual-layer oxide on the interface contacted to LBE,consisting of an outer magnetite layer and an inner Fe-Cr spinel layer.Meanwhile,the amorphous coating with a high glass transition temperature(Tg=550℃)and crystallization temperature(T_(x)=600℃)exhibited dramatically enhanced thermal stability and corrosion resistance.No visible LBE penetration was observed,although small amounts of Fe_(3)O_(4),Cr_(2)O_(3),and PbO were found on the coating surface.In addition,the amorphicity and interface bonding of the coating layer remained unchanged after the LBE corrosion.The Fe-based amorphous coating can act as a stable barrier layer in liquid LBE and have great application potential for long-term service in LBE-cooled fast reactors.
文摘The tensile tests of T91 and T91Si steels at 200-450℃in air and at 350℃in oxygen-depleted liquid lead-bismuth eutectic(LBE)environment with strain rate of 1×10^(-5)-5×10^(-3)were performed.Results show that the activation energy of T91 steel is 103.45-246.76 kJ/mol and that of T91Si steel is 146.98-172.11 kJ/mol when Portevin-Le Chatelie(PLC)phenomenon occurs.The elongation reduction of T91 steel at 350℃is not specific to LBE environment,whereas the presence of LBE promotes crack initiation and propagation and affects the elongation of the material in the necking stage.With Si addition,the elongation,especially the uniform elongation at 350℃in LBE environment,improves,and the tendency toward crack propagation in T91 steel after slow tensile necking is reduced.The PLC phenomenon can be seen in both T91 and T91Si steels at high temperatures owing to the dynamic strain aging(DSA).The temperature ranges are different when DSA occurs,with 300-350℃and 250-350℃for T91 and T91Si steels,respectively.
基金the National Natural Science Foundation of China(Grant No.U1832206).
文摘Classical molecular dynamics simulations with global neural network machine learning potential are used to study early stage oxidation and dissolution behaviors of bcc Fe surfaces contacting with stagnant oxygen dissolved liquid leadbismuth eutectic(LBE-O).Both static and dynamic simulation results indicate that the early stage oxidation and dissolution behaviors of bcc Fe show strong orientation dependence under the liquid LBE environments,which may explain the experimental observations of uneven interface between iron-based materials and liquid LBE.Our investigations show that it is the delicate balance between the oxide growth and metal dissolution that leads to the observed corrosion anisotropy for bcc Fe contacting with liquid LBE-O.
基金Funded by the National Natural Science Foundation of China(No.91226203)
文摘Studies of synergetic irradiation effects and liquid lead-bismuth eutectic(LBE) corrosion/embrittlement effects on ferritic/martensitic(F/M) steels are of great importance for developing high power spallation neutron targets(>1 M W) such as the European Spallation Source(ESS) and Accelerator Driven System(ADS) facilities that can be used for transmuting long-lifetime radioactive wastes. Liquid LBE(45Pb-55Bi,in terms of mass fraction) has been selected as the candidate target material in high power spallation neutron targets due to its favourable thermal,physical & chemical properties,and to its high spallation neutron yield. 9Cr F/M steels such as T91(9Cr1M oVNb,in terms of mass fraction) have been chosen as the structural material for the targets due to their good mechanical properties and good resistance to irradiation induced swelling in fission neutron irradiation environments. For developing high power spallation neutron targets,behaviors of F/M steels in spallation neutron target irradiation environments and LBE corrosion/embrittlement effects have been extensively studied. However,many open questions have not been answered. The aim of this paper is to describe the present research situation on this topic. The obtained experimental data about LBE embrittlement effects on F/M steels is summarized and the influence of different parameters involved is analyzed to understand the influence effect on LBE embrittlement effect of F/M s.
基金supported by the National Natural Science Foundation of China with Grant Nos.51375216 and 51505197the Open-Fund Research of State Key Lab of Advanced Welding and Joining with Grant No.AWJ-16-M07the Fusion Digital Simulation(FDS)Team for support the CLAM steel
文摘The cavitation erosion of weld joint and base metal of China low activation martensitic（CLAM）steel in liquid lead-bismuth eutectic alloy（LBE）at 550°C was investigated to simulate the cavitation erosion of the first wall and the nuclear main pump impeller in the accelerator driven sub-critical system（ADS）.A suit of ultrasonic cavitation facility was self-designed to study the cavitation erosion.By studying the surface micro topography,roughness and mean pit depth of the tested specimens,it was found that some crater clusters and large scale cracks appeared on the tested specimen surface after the formation of numerous single craters,and the base metal exhibited much better cavitation erosion resistance than the weld bead due to the difference in their mechanical properties and microstructures.In addition,by comparing the results of static corrosion and cavitation erosion,it could be concluded that the cavitation erosion and the dissolution and oxidation corrosion in liquid LBE would accelerate mutually.
基金supported by the National Natural Science Foundation of China(No.52301121).
文摘This study investigates the impact of silicon(Si)on the corrosion resistance and post-corrosion toughness of ferrite/martensitic(F/M)steels in a liquid lead-bismuth eutectic(LBE)environment.Corrosion tests were performed on HT-9 and EP-823(1.17 wt%Si)steels at 550℃for 1000 h under oxygen-controlled conditions.The resulting oxide layer consisted of an outer magnetite layer,a spinel layer and an inner oxide zone(IOZ).A Si-rich oxide layer was identified within the spinel and IOZ layers of EP-823,which slowed the growth rate of the oxide layer,enhanced antioxidant performance,and inhibited dissolution corrosion by the LBE.Post-corrosion mechanical properties were evaluated using a small punch test.Results showed a significant reduction in HT-9's toughness within 240 h of corrosion,while EP-823 exhibited increased brittleness after 500 h due to Si-promoted carbide and Laves phase precipitation,significantly reducing its toughness.
文摘To better understand the stainless steel corrosion behavior in lead-bismuth eutectic flow,the iron mass transfer phenomenon on roughened walls under various pipe flow conditions were numerically investigated.Low Reynolds number k-εmodel was applied in CFD simulation of mass transfer,in which the Reynolds number covers from 5×10^(3) to 1×10^(5).
文摘The performance degradation of structural materials caused by corrosion of the coolant lead-bismuth eutectic(LBE)alloy has become one of the most serious challenges facing the construction of lead-cooled fast reactors^([13]).Grain re nement is a way to improve the corrosion resistance of steels[4-8].However,its e ect on the LBE corrosion behavior of steels is still very little studied.In this study.
文摘Lead-bismuth eutectic(LBE)is a promising candidate material of core coolants and high-power spallation targets of accelerator driven system(ADS)for transmutation of radioactive wastes and of coolants of fast reactors(FRs).
文摘The Lead-cooled Fast Reactor(LFR)is one of the fourth-generation nuclear energy systems with excellent development prospects.Liquid lead-bismuth eutectic(LBE)(44.5wt.%Pb+55.5wt.%Bi)appears to be a promising candidate as a coolant for LFR due to its low melting point of 397 K,fast heat removing from the target,good neutron yield and low vapour pressure.However,the liquid LBE is corrosive to both austenitic steels and ferriticmartensitic steels.
基金supported by the National Key R&D Program of China(2020YFB1901900)。
文摘Investigations on entropy generation and thermal irreversibility analysis are conducted for liquid lead-bismuth eutectic(LBE)in an annular pipe.To find better performance in convective heat transfer,the computational fluid dynamics(CFD)code based on the finite volume method(FVM)is adopted to solve this problem.The elevated temperature LBE flows in the annular pipe,and four types of heat flux,including constant,linear increase and decrease,and parabolic distributions are imposed at the inside wall of the annular pipe.The investigations are conducted for the specific average heat input of 200 kW/m^(2),and the different Peclet number Pe is set from 1200 to 3200.The SST k-ωturbulent model and Cheng-Tak Prt model are adopted.The mesh independence validation and models verification are also conducted and the maximum Nu error is 5.43%compared with previous experimental correlations.The results from the local and system scales,respectively,including volumetric dimensionless entropy generation,Ns,Be,and Ep,are discussed.The results indicate that the viscous friction and heat transfer caused by entropy generation can be found in the viscous sub-layer and buffer layer respectively.Heat transfer is the primary factor that leads to irreversible losses.Besides,the results show that the best thermodynamic performance occurs under parabolic distributed heat flux in the research scope.
基金financially supported by the Natural Science Spe-cial(Special Post)Research Foundation of Guizhou University(No.2023-46)the Youth Science and Technology Talent Development Program of Guizhou(No.QKJ[2024]24)the National Natural Science Foundation of China(Nos.52274260,52074096,and 52164017).
文摘Dual-phase heterogeneous structures confer eutectic high-entropy alloy(EHEA)with excellent strength-ductility synergy under quasi-static tensile loading.However,it is questionable whether the EHEAs pos-sess equally good impact toughness because the phase interfaces are vulnerable to crack initiation.This work aimed to study the Charpy impact toughness and fracture behavior of AlCoCrFeNi_(2.1) EHEA.The results indicate that while maintaining high tensile strength and ductility,the AlCoCrFeNi_(2.1) EHEA also shows a satisfactory impact toughness of 25.86 J/cm^(2),superior to most other dual-phase alloys like TC4 titanium alloy or DP steel.Fractography analysis reveals characteristic regions of the fracture surface,which suggests energy absorption mechanisms primarily through ductile dimples,flat cleavage facets,secondary cracks,and microvoids,corresponding to a ductile-brittle mixed fracture mode.Detailed obser-vations of the deformed microstructure through TEM and EBSD demonstrate that FCC(L1_(2))and BCC(B2)phases underwent concurrent tearing along their phase boundaries,indicating a crucial influence of phase boundaries over crack initiation and propagation.The FCC(L1_(2))phase bore almost all plastic deformation of the sample through dislocation slip,whereas the BCC(B2)phase underwent a rapid shearing but almost no dislocation slip.Crack initiation under impact loading typically starts at the FCC(L1_(2))/BCC(B2)inter-face before propagating through the BCC(B2)phase.Additionally,this work further examines the effect of sample size and notch shape on the impact toughness of AlCoCrFeNi_(2.1) EHEA.A comparative analysis of the mechanical behavior under static and impact loading was also conducted,highlighting differences and connections in stress distribution and fracture surface morphology.The study offers valuable insights into the mechanical response and fracture behavior of AlCoCrFeNi_(2.1) EHEA under impact loading,provid-ing crucial information for its potential industrial applications.
基金supported by the National Natural Science Foundation of China(Nos.22208221,22178221)the Natural Science Foundation of Guangdong Province(Nos.2024A1515011078,2024A1515011507)+1 种基金the Shenzhen Science and Technology Program(Nos.JCYJ20220818095805012,JCYJ20230808105109019)the Start-up Research Funding of Shenzhen University(No.868-000001032522).
文摘The deterioration of aqueous zinc-ion batteries(AZIBs)is confronted with challenges such as unregulated Zn^(2+)diffusion,dendrite growth and severe decay in battery performance under harsh environments.Here,a design concept of eutectic electrolyte is presented by mixing long chain polymer molecules,polyethylene glycol dimethyl ether(PEGDME),with H_(2)O based on zinc trifluoromethyl sulfonate(Zn(OTf)2),to reconstruct the Zn^(2+)solvated structure and in situ modified the adsorption layer on Zn electrode surface.Molecular dynamics simulations(MD),density functional theory(DFT)calculations were combined with experiment to prove that the long-chain polymer-PEGDME could effectively reduce side reactions,change the solvation structure of the electrolyte and priority absorbed on Zn(002),achieving a stable dendrite-free Zn anode.Due to the comprehensive regulation of solvation structure and zinc deposition by PEGDME,it can stably cycle for over 3200 h at room temperature at 0.5 mA/cm^(2)and 0.5 mAh/cm^(2).Even at high-temperature environments of 60℃,it can steadily work for more than 800 cycles(1600 h).Improved cyclic stability and rate performance of aqueous Zn‖VO_(2)batteries in modified electrolyte were also achieved at both room and high temperatures.Beyond that,the demonstration of stable and high-capacity Zn‖VO_(2)pouch cells also implies its practical application.
基金supported by the National Nat-ural Science Foundation of China(Nos.51872238,52074227,and 21806129)the Fundamental Research Funds for the Central Universities,China(Nos.3102018zy045 and 3102019AX11)+2 种基金the Guangdong Basic and Applied Basic Research Foundation,China(No.2024A1515010298)the Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2017JQ5116 and 2020JM-118)the Key Laboratory of Icing and Anti/De-icing of CARDC(No.IADL20220401).
文摘Gels and conductive polymer composites,including hydrogen bonds(HBs),have emerged as promising materials for electro-magnetic wave(EMW)absorption across various applications.However,the relationship between conduction loss in EMW-absorbing materials and charge transfer in HB remains to be fully understood.In this study,we developed a series of deep eutectic gels to fine-tune the quantity of HB by adjusting the molar ratio of choline chloride(ChCl)and ethylene glycol(EG).Owing to the unique properties of deep eutectic gels,the effects of magnetic loss and polarization loss on EMW attenuation can be disregarded.Our results indicate that the quantity of HB initially increases and then decreases with the introduction of EG,with HB-induced conductive loss following similar pat-terns.At a ChCl and EG molar ratio of 2.4,the gel labeled G22-CE2.4 exhibited the best EMW absorption performance,characterized by an effective absorption bandwidth of 8.50 GHz and a thickness of 2.54 mm.This superior performance is attributed to the synergistic ef-fects of excellent conductive loss and impedance matching generated by the optimal number of HB.This work elucidates the role of HB in dielectric loss for the first time and provides valuable insights into the optimal design of supramolecular polymer absorbers.
基金supported by the National Natural Science Foundation of China(Nos.52130204,52174376,52202070,51822405)Guangdong Basic and Applied Basic Research Foundation(No.2021B1515120028)+6 种基金TQ Innovation Foundation(No.23-TQ09-02-ZT-01-005)Aeronautical Science Foundation of China(No.20220042053001)Science and Technology Innovation Team Plan of Shaanxi Province(No.2021TD-17)Key R&D Project of Shaanxi Province(No.2024GX-YBXM-220)Thousands Person Plan of Jiangxi Province(JXSQ2020102131)Fundamental Research Funds for the Central Universities(Nos.D5000230348,D5000220057)China Scholarship Council(Nos.202206290133,202306290190).
文摘As a 3D printing method,laser powder bed fusion(LPBF)technology has been extensively proven to offer significant advantages in fabricating complex structured specimens,achieving ultra-fine microstructures,and enhancing performances.In the domain of manufacturing melt-grown oxide ceramics,it encounters substantial challenges in suppressing crack defects during the rapid solidification process.The strategic integration of high entropy alloys(HEA),leveraging the significant ductility and toughness into ceramic powders represents a major innovation in overcoming the obstacles.The ingenious doping of HEA parti-cles preserves the eutectic microstructures of the Al_(2)O_(3)/GdAlO_(3)(GAP)/ZrO_(2)ceramic composite.The high damage tolerance of the HEA alloy under high strain rates enables the absorption of crack energy and alleviation of internal stresses during LPBF,effectively reducing crack initiation and growth.Due to in-creased curvature forces and intense Marangoni convection at the top of the molt pool,particle collision intensifies,leading to the tendency of HEA particles to agglomerate at the upper part of the molt pool.However,this phenomenon can be effectively alleviated in the remelting process of subsequent layer de-position.Furthermore,a portion of the HEA particles partially dissolves and sinks into the molten pool,acting as heterogeneous nucleation particles,inducing the formation of equiaxed eutectic and leading pri-mary phase nucleation.Some HEA particles diffuse into the lamellar ternary eutectic structures,further promoting the refinement of eutectic microstructures due to increased undercooling.The innovative dop-ing of HEA particles has effectively facilitated the fabrication of turbine-structured,conical,and cylindrical ternary eutectic ceramic composite specimens with diameters of about 70 mm,demonstrating significant developmental potential in the field of ceramic composite manufacturing.
基金financially supported by the Original Exploration Project of the National Natural Science Foundation of China(No.52150079)the National Natural Science Foundation of China(Nos.U22A20130,U2004215,and 51974280)+1 种基金the Natural Science Foundation of Henan Province of China(No.232300421196)the Project of Zhongyuan Critical Metals Laboratory of China(Nos.GJJSGFYQ202304,GJJSGFJQ202306,GJJSGFYQ202323,GJJSGFYQ202308,and GJJSGFYQ202307)。
文摘Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.
