China Low Activation Martensitic （CLAM） steel is being studied to develop the structural materials for a fusion reactor, which has been designed based on the well-known 9Crl.5WVTa steel. The effect of tempering temp...China Low Activation Martensitic （CLAM） steel is being studied to develop the structural materials for a fusion reactor, which has been designed based on the well-known 9Crl.5WVTa steel. The effect of tempering temperature on hardness and micro- structure of CLAM steel was studied. The strength of CLAM steel increased by adding silicon, and the ductility remained con- stant. Conversely, while CLAM steel maintained good ductility with the addition of yttrium, its tensile strengths were greatly degraded. Behaviors under electron irradiation of CLAM steel were examined using the high voltage electron microscope. Electron irradiation at 450℃ formed many voids in CLAM steel with basic composition, whereas CLAM with silicon steel did not change the microstructure significantly.展开更多
Maintaining the safety and reliability of nuclear engineering materials under a neutron irradiation environment is significant. Atomic-scale simulations are conducted to investigate the mechanism of irradiation-induce...Maintaining the safety and reliability of nuclear engineering materials under a neutron irradiation environment is significant. Atomic-scale simulations are conducted to investigate the mechanism of irradiation-induced vacancy formation in CLAM, F82 H and α-Fe with different neutron energies and objective laws of the effect of vacancy concentration on mechanical properties of α-Fe. Damage of these typical metal engineering materials caused by neutrons is mainly displacement damage, while the displacement damage rate and the non-ionizing effect of neutrons decrease with the increase of neutron energy. The elastic modulus, yield strength, and ultimate strength of α-Fe are in the order of magnitude of GPa. However, the elastic modulus is not constant but decreases with the increase of strain at the elastic deformation stage. The ultimate strength reaches its maximum value when vacancy concentration in α-Fe is 0.2%. On this basis, decreasing or increasing the number of vacancies reduces the ultimate strength.展开更多
The design of high irradiation-resistant materials is very important for the development of next-generation nuclear reactors. Grain boundaries acting as effective defect sinks are thought to be able to moderate the de...The design of high irradiation-resistant materials is very important for the development of next-generation nuclear reactors. Grain boundaries acting as effective defect sinks are thought to be able to moderate the deterioration of mechanical behaviors of irradiated materials, and have drawn increasing attention in recent years. The study of the effect of grain boundaries on the mechanical behaviors of irradiated materials is a multi-scale problem. At the atomic level, grain boundaries can effectively affect the production and formation of irradiation-induced point defects in grain interiors, which leads to the change of density, size distribution and evolution of defect clusters at grain level. The change of microstructure would influence the macroscopic mechanical properties of the irradiated polycrystal. Here we give a brief review about the effect of grain boundaries on the mechanical behaviors of irradiated metals from three scales: microscopic scale, mesoscopic scale and macroscopic scale.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 50971030)the National Basic Research Program of China (Grant Nos. 2009GB109004 and 2011GB108004)
文摘China Low Activation Martensitic （CLAM） steel is being studied to develop the structural materials for a fusion reactor, which has been designed based on the well-known 9Crl.5WVTa steel. The effect of tempering temperature on hardness and micro- structure of CLAM steel was studied. The strength of CLAM steel increased by adding silicon, and the ductility remained con- stant. Conversely, while CLAM steel maintained good ductility with the addition of yttrium, its tensile strengths were greatly degraded. Behaviors under electron irradiation of CLAM steel were examined using the high voltage electron microscope. Electron irradiation at 450℃ formed many voids in CLAM steel with basic composition, whereas CLAM with silicon steel did not change the microstructure significantly.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20133218110023)China Postdoctoral Science Foundation(Grant No.2014M561642)+2 种基金the Jiangsu Planned Projects for Postdoctoral Research Funds(Grant No.1401091C)the Fundamental Research Funds for the Central Universities(Grant No.3082015NJ20150021)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Maintaining the safety and reliability of nuclear engineering materials under a neutron irradiation environment is significant. Atomic-scale simulations are conducted to investigate the mechanism of irradiation-induced vacancy formation in CLAM, F82 H and α-Fe with different neutron energies and objective laws of the effect of vacancy concentration on mechanical properties of α-Fe. Damage of these typical metal engineering materials caused by neutrons is mainly displacement damage, while the displacement damage rate and the non-ionizing effect of neutrons decrease with the increase of neutron energy. The elastic modulus, yield strength, and ultimate strength of α-Fe are in the order of magnitude of GPa. However, the elastic modulus is not constant but decreases with the increase of strain at the elastic deformation stage. The ultimate strength reaches its maximum value when vacancy concentration in α-Fe is 0.2%. On this basis, decreasing or increasing the number of vacancies reduces the ultimate strength.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11225208 and 11521202)
文摘The design of high irradiation-resistant materials is very important for the development of next-generation nuclear reactors. Grain boundaries acting as effective defect sinks are thought to be able to moderate the deterioration of mechanical behaviors of irradiated materials, and have drawn increasing attention in recent years. The study of the effect of grain boundaries on the mechanical behaviors of irradiated materials is a multi-scale problem. At the atomic level, grain boundaries can effectively affect the production and formation of irradiation-induced point defects in grain interiors, which leads to the change of density, size distribution and evolution of defect clusters at grain level. The change of microstructure would influence the macroscopic mechanical properties of the irradiated polycrystal. Here we give a brief review about the effect of grain boundaries on the mechanical behaviors of irradiated metals from three scales: microscopic scale, mesoscopic scale and macroscopic scale.
