High temperature fracture characteristics of a nanostructured ferritic alloy (NFA)

FCRD Milestone Report: M21AF050901

“…This result showing a decrease in fracture toughness as temperature increases was first observed in the fracture toughness study of 14YWT [4]. In this study, the fracture toughness of 14YWT (SM10 heat) was above 140 MPa√m at low temperatures, room temperature (RT) and 200 °C, but decreased to a low fracture toughness range of 52-82 MPa√m at higher temperatures up to 700 °C.…”

Temperature dependence of strengthening mechanisms in the nanostructured ferritic alloy 14YWT: Part I—Mechanical and microstructural observations

“…Thus far, however, the body of tensile YS data at very low temperatures has not been accumulated. Only fracture toughness testing conducted below room temperature is available [16,17].…”

Irradiation dose and temperature dependence of fracture toughness in high dose HT9 steel from the fuel duct of FFTF

“…Over the past few decades, the normalized and tempered HT9 steel (also called the 12Cr-1MoVW steel) has been the most important alloy for the core structures of sodium-cooled fast reactors (SFRs) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The successful operation of the Fast Flux Testing Facility (FFTF) at Hanford site during 1980-1992 was a monumental demonstration for its in-reactor performance, where the key core components including fuel claddings and ducts are made of HT9 steel [8].…”

“…The severe environments in such reactors, high temperature and high fast neutron flux, require the core materials to maintain dimensional stability, high temperature strength, and cracking resistance after operation to very high doses (>100 dpa). Since the most critical mechanical property for the structural integrity assessment of such core components is considered to be a high cracking resistance, fracture characteristics for the HT9 steel have been investigated extensively and published in a variety of literature [9][10][11][12][13][14][15][16][17][18][19].…”