Reduced-activation ferritic/martensitic steels(RAFMs) such as CLF-1 steel, have been developed as candidate structural materials for breeding blanket in fusion reactors. Hot isostatic pressing(HIP) diffusion method is...Reduced-activation ferritic/martensitic steels(RAFMs) such as CLF-1 steel, have been developed as candidate structural materials for breeding blanket in fusion reactors. Hot isostatic pressing(HIP) diffusion method is expected to provide the most promising method to solve the problem to join cooling rectangular channels with thin panels during fabrication of the first wall in breeding blankets. Mechanical and microstructural characterization of HIPed joints of CLF-1 steel with four typical surface roughness has been investigated. The results indicate that with the increase of surface roughness, the tensile properties are similar to as-received CLF-1 steel, the elongation and the area reduction decreased, the impact energy decreased sharply. The HIPed joints are very sensitive to the bonding surface states, the roughness could influence degassing, oxide and cavities formation, diffusion efficiency of bonding surface, and reduce the roughness, efficient degassing and elimination of oxide formation of the HIP joint surfaces is important to obtain a satisfactory joint.展开更多
In the present work,the irradiation hardening behavior of a Chinese low-activation ferritic/martensitic steel CLF-1,a candidate for fusion reactor blankets,is studied.Specimens were irradiated with high-energy14N and5...In the present work,the irradiation hardening behavior of a Chinese low-activation ferritic/martensitic steel CLF-1,a candidate for fusion reactor blankets,is studied.Specimens were irradiated with high-energy14N and56Fe ions at the terminal of a cyclotron to three successively increasing damage levels of 0.05,0.1 and 0.2 displacements per atom(dpa)at about-50°C.The energy of the incident ions was dispersed to 11 successively decreasing grades using an energy degrader,thereby generating an atomic displacement damage plateau in the specimens from the surface to a depth of 25μm,which is sufficiently broad for the Vickers hardness test.Eight different loads(i.e.98 mN,196 m N,490 m N,980 m N,1.96 N,4.9 N,9.8 N and 19.6 N)were applied to the specimens to obtain the depth profiles of the Vickers hardness by using a microhardness tester.Hardening was observable at the lowest damage level,and increased with increasing irradiation dose.A power-law correlation of the Vickers hardness with the damage level(HV0=1.49+0.76 dpa0.31)is proposed.Testing with a nano-indentation technique was also performed,and a linear relationship between the Vickers micro-hardness and the nanohardness(HV0=0.83 H0)was observed.A comparison with other RAFM steels(CLAM,JLF-1,F82 H,EUROFER97 etc.)under neutron or charged particle irradiation conditions shows that most of the RAFM steels exhibit similar power-law exponents in the dose dependence of irradiation hardening.The difference in the irradiation hardening may be attributed to differences in microstructure prior to irradiation.展开更多
基金supported by the National Key R&D Program of China with grant numbers 2017YFE0300601the open project of Beijing Engineering Researching Center of Laser Technology with grant numbers BG00462018-02。
文摘Reduced-activation ferritic/martensitic steels(RAFMs) such as CLF-1 steel, have been developed as candidate structural materials for breeding blanket in fusion reactors. Hot isostatic pressing(HIP) diffusion method is expected to provide the most promising method to solve the problem to join cooling rectangular channels with thin panels during fabrication of the first wall in breeding blankets. Mechanical and microstructural characterization of HIPed joints of CLF-1 steel with four typical surface roughness has been investigated. The results indicate that with the increase of surface roughness, the tensile properties are similar to as-received CLF-1 steel, the elongation and the area reduction decreased, the impact energy decreased sharply. The HIPed joints are very sensitive to the bonding surface states, the roughness could influence degassing, oxide and cavities formation, diffusion efficiency of bonding surface, and reduce the roughness, efficient degassing and elimination of oxide formation of the HIP joint surfaces is important to obtain a satisfactory joint.
基金sponsored by the National Magnetic Confinement Fusion Program(No.2011GB108003)National Natural Science Foundation of China(No.U1532262)。
文摘In the present work,the irradiation hardening behavior of a Chinese low-activation ferritic/martensitic steel CLF-1,a candidate for fusion reactor blankets,is studied.Specimens were irradiated with high-energy14N and56Fe ions at the terminal of a cyclotron to three successively increasing damage levels of 0.05,0.1 and 0.2 displacements per atom(dpa)at about-50°C.The energy of the incident ions was dispersed to 11 successively decreasing grades using an energy degrader,thereby generating an atomic displacement damage plateau in the specimens from the surface to a depth of 25μm,which is sufficiently broad for the Vickers hardness test.Eight different loads(i.e.98 mN,196 m N,490 m N,980 m N,1.96 N,4.9 N,9.8 N and 19.6 N)were applied to the specimens to obtain the depth profiles of the Vickers hardness by using a microhardness tester.Hardening was observable at the lowest damage level,and increased with increasing irradiation dose.A power-law correlation of the Vickers hardness with the damage level(HV0=1.49+0.76 dpa0.31)is proposed.Testing with a nano-indentation technique was also performed,and a linear relationship between the Vickers micro-hardness and the nanohardness(HV0=0.83 H0)was observed.A comparison with other RAFM steels(CLAM,JLF-1,F82 H,EUROFER97 etc.)under neutron or charged particle irradiation conditions shows that most of the RAFM steels exhibit similar power-law exponents in the dose dependence of irradiation hardening.The difference in the irradiation hardening may be attributed to differences in microstructure prior to irradiation.
