Reduced Activation Ferritic Steel R&D Based on JUPITER-1 Results

Abstract The US/Japan collaboration (Japan-US Program of Irradiation Tests for Fusion Research: JUPITER) has been effective in accumulating an irradiation database and in understanding the mechanism of irradiation effects of reduced activation ferritic steels (RAFS). The irradiation data obtained up to now indicates rather high feasibility of ferritic steel for application to fusion reactors, because of their high resistance to degradation of material performance by both the displacement damage and helium. The martensitic structure of the RAFS consists of a kind of lattice defects before the irradiation, such as dislocations, lath boundaries, precipitates and carbides, which strongly reinforce the resistance to displacement damages through absorption and annihilation of the point defects generated by the irradiation. Transmutation helium can be trapped at those defects in the martensitic structure so that the formation of helium clusters at grain boundaries, which causes intergranular embrittlement, is suppressed. The martensitic structure of the RAFS is considered to be appropriate for fusion structural material. Efforts to increase high temperature strength have been made for RAFS.

[1]  H. Matsui,et al.  High resistance to helium embrittlement in reduced activation martensitic steels , 2002 .

[2]  N. Yoshida,et al.  Effects of dislocation on thermal helium desorption from iron and ferritic steel , 2002 .

[3]  Ryuta Kasada,et al.  Annealing behavior of irradiation hardening and microstructure in helium-implanted reduced activation martensitic steel , 2000 .

[4]  H. Matsui,et al.  Two-Step Recovery Process of Irradiation Hardening in 1%Ni Doped 9%Cr-2%W Martensitic Steel , 2000 .

[5]  A. Hishinuma,et al.  Low-temperature irradiation effects on tensile and Charpy properties of low-activation ferritic steels , 2000 .

[6]  M. L. Hamilton,et al.  A review of some effects of helium on charpy impact properties of ferritic/martensitic steels , 1998 .

[7]  Akira Kohyama,et al.  Dependence of impact properties on irradiation temperature in reduced-activation martensitic steels , 1998 .

[8]  Akira Kohyama,et al.  Current status and future R&D for reduced-activation ferritic/martensitic steels , 1998 .

[9]  H. Matsui,et al.  Void swelling of Japanese candidate martensitic steels under FFTF/MOTA irradiation , 1996 .

[10]  M. L. Hamilton,et al.  Tensile properties of reduced activation Fe-9Cr-2W steels after FFTF irradiation , 1994 .

[11]  H. Matsui,et al.  Behavior of helium gas atoms and bubbles in low activation 9Cr martensitic steels , 1994 .

[12]  R. Klueh,et al.  Effect of irradiation in HFIR on tensile properties of Cr-Mo steels , 1992 .

[13]  H. Kayano,et al.  Irradiation-induced suppression of creep in a low activation 9%Cr-2%W steel , 1991 .

[14]  M. Narui,et al.  Effects of neutron irradiation on hydrogen-induced intergranular fracture in a low activation 9%Cr-2%W steel , 1991 .

[15]  R. Klueh,et al.  Impact behavior of 9Cr-1MoVNb and 12Cr-1MoVW steels irradiated in HFIR☆ , 1991 .

[16]  M. Narui,et al.  Effects of small changes in alloy composition on the mechanical properties of low activation 9%Cr-2%W steel , 1991 .

[17]  H. Matsui,et al.  Evaluation of Ductile-Brittle Transition Behavior of Helium-implanted Reduced Activation 9Cr-2W Martensitic Steel by Small Punch Tests , 2000 .