Radiation hardening and -embrittlement due to He production in F82H steel irradiated at 250°C in JMTR

Mechanical properties of small size specimens of F82H steel

“…However, there was a possibility that the addition of boron or nickel may cause severe irradiation embrittlement. In this experiment, there are no effects of chemical additional element on DBTT [16,17], the shift of DBTT [11], the increment of irradiation hardening [18,19] and defect clusters [20,21] as reported in previous studies. It is therefore concluded that helium production can affect the shift of DBTT.…”

“…In this study, the change of DBTT due to displacement damage hardly occurred in this experiment and it was about 2-3 • C. In the previous study [11] of 50 MeV He 2+ irradiation experiment, displacement damage in F82H steel was also about 0.03 dpa and the projected range of the helium ions controlled under an energy degrader was from 0 to 0.4 mm, and helium atoms were uniformly implanted to about 85 appm at about 100 • C in the specimen with 0.3 mm in thickness. The shift of DBTT for the F82H steel implanted with 85 appm He was about 15 • C [11]. The summaries of SP data tested at RT in F82H steel were given in Table 2.…”

Effect of irradiation-induced plastic flow localization on ductile crack resistance behavior of a 9%Cr tempered martensitic steel

“…However, the use of small samples may induce a loss of constraint that can locally modify the structure and lead to apparent high toughness. There was also much attention paid to the small punch test and many correlations were established between the DBTT measured from Charpy impact data and small punch tests [118][119][120][121][122][123][124][125][126][127][128][129]. However, as shown in this work, these correlations might be biased by the loading rate.…”

Effect of gas atoms and displacement damage on mechanical properties and microstructures of F82H

“…These systems are desired to operate at relatively higher temperatures. It is reported that helium atoms can affect DBTT [3][4][5][6][7], swelling behavior [8][9][10][11][12][13][14][15] and irradiation hardening [16][17][18][19][20][21][22][23] in martensitic steels. To study the synergistic effects of displacement damage and helium on mechanical properties and microstructure, there are some specific experimental methods.…”