The effect of solid transmutation products on swelling in 316 stainless steel

Neutron irradiation effects in fusion or spallation structural materials: Some recent insights related to neutron spectra

“…in fast reactor spectra and were of only minor consequence in highly thermalized reactor spectra [46,47]. The near-total loss of the minor alloying element Mn by (n,r) reactions in HFIR was thought not to affect void swelling, although the conclusion was actually based on the behavior of a range of Mn-modified variants of 316 steel studied in the EBR-I1 fast reactor [46]. The slower tendency in fusion spectra to increase Mn content by (n,p) and (n,Zn) reactions was also thought to be of no real consequence.…”

“…The fracture mode is intergranular in nature for the depth of one grain and transgranular beyond one grain depth [43]. in fast reactor spectra and were of only minor consequence in highly thermalized reactor spectra [46,47]. The near-total loss of the minor alloying element Mn by (n,r) reactions in HFIR was thought not to affect void swelling, although the conclusion was actually based on the behavior of a range of Mn-modified variants of 316 steel studied in the EBR-I1 fast reactor [46].…”

“…Some of these alloys were also strengthened with W and V. Although the Mn content will increase in fusion-relevant neutron spectra, the presence of thermal neutrons in test reactors can cause a very strong depletion of manganese. In HFIR -80% of the original manganese is removed by 80 dpa [46]. In light water power reactors the thermal-tofast neutron ratio is lower by a factor of N 4, and the loss of Mn in a pressurized water reactor baMe bolt has been calculated by the authors to be -46% at 100 dpa.…”

Assessment of XM-19 as a Substitute for AISI 348 in ATR Service

“…10,11,12 In the 300 series steels operating in highly thermalized neutron spectra characteristic of ATR, the Mn will strongly transmute to Fe. 13 Normally, this transformation is not a concern in 300 series alloys since the Mn level is usually low, at 1-2%, and its loss does not severely impact the stability of the austenite phase.…”

“…There is additional transmutation of Cr to produce small amounts of V, which leads to a modification of carbide composition, but no identifiable metallurgical consequences or property changes have been observed, especially in alloys already containing measurable amounts of V. 13 The percentage loss of Cr from the matrix is relatively small and insignificant; therefore it probably can be ignored.…”