论文信息 - Helium effects on microstructural evolution in tempered martensitic steels: In situ helium implanter studies in HFIR

Helium effects on microstructural evolution in tempered martensitic steels: In situ helium implanter studies in HFIR

Abstract Microstructural evolutions in tempered martensitic steels (TMS) under neutron-irradiation, at fusion relevant He/dpa ratios and dpa rates, were characterized using a novel in situ He-implanter technique. F82H-mod3 was irradiated at 500 °C in HFIR to a nominal 9 dpa and 190 or 380 appm He in both in the as-tempered (AT) and 20% cold-worked (CW) conditions. In all cases, a high number density of 1–2 nm He-bubbles were observed, along with fewer but larger ≈10 nm void-like faceted cavities. The He-bubbles form preferentially on dislocations and various interfaces. A slightly larger number of smaller He bubbles were observed in the CW condition. The lower He/dpa ratio produced slightly smaller and fewer He-bubbles. Comparisons of these observations to the results in nano-structured ferritic alloy (NFA) MA957 provide additional evidence that TMS may be susceptible to He-embrittlement as well as void swelling at fusion relevant He concentrations, while NFA are much more resistant to these degradation phenomena.

[1] R. Stoller,et al. Analytical solutions for helium bubble and critical radius parameters using a hard sphere equation of state , 1985 .

[2] H. Trinkaus. On the modeling of the high-temperature embrittlement of metals containing helium , 1983 .

[3] G. Odette,et al. The transport and fate of helium in nanostructured ferritic alloys at fusion relevant He/dpa ratios and dpa rates , 2007 .

[4] B. M. Oliver,et al. The transport and fate of helium in martensitic steels at fusion relevant He/dpa ratios and dpa rates , 2007 .

[5] G. Odette. A model for in-reactor stress rupture of austenitic stainless steels , 1984 .

[6] Mikio Enoeda,et al. Reduced activation martensitic steels as a structural material for ITER test blanket , 2004 .

[7] G. Robert Odette,et al. On the effects of irradiation and helium on the yield stress changes and hardening and non-hardening embrittlement of ∼8Cr tempered martensitic steels : Compilation and analysis of existing data , 2006 .