Mechanism of instability of carbides in Fe–TaC alloy under high energy electron irradiation at 673 K

Stability of oxide particles under electron irradiation in a 9Cr ODS steel at 400 °C

“…1. Note that the flux was defined for each nanoparticle according to its distance from the beam center [12,13]. Therefore in the following discussion we describe the result from the highest electron intensity -center of the beam, to the lower electron intensity -periphery of the beam.…”

“…In the case 2 MeV-1.1 nA, only (a) and (b) regimes were included and in the case 2 MeV-0.42 nA, only (a) regime was included. As is modeled in [12,13], the instability of the nanoparticles can be explained by enhanced diffusion due to irradiation induced defects, and/or by atomic displacement of the constituent atoms of the nanoparticles, both of which assists dissolution of constituent atom of nanoparticles into matrix. The amount and mobility of the vacancies affect the solute atom diffusion.…”

APT characterization of irradiation effects on MX phase in reduced-activation ferritic/martensitic steels

“…It has also been proven that the addition of nitrogen in pure tantalum changes the prevailing microscopic diffusion mechanism of H [34] . Many researchers found that the additional nitrogen decreases the diffusivity of hydrogen [34] and contributes to hydrogen trapping with a small trapping enthalpy in tantalum [35] . In the nitride, the high concentration of hydrogen with Ta x C y N z H h n + forms indicates some special connection among Ta, N, C and H in the MX nanoprecipitate.…”

“…In these materials, irradiation can induced the nano-sized cluster formation [ 1 , 2 , 7 , 12-18 ] and grain boundary segregation [ 3 , 6 , 13 , 14 , 18 ]. ied under irradiation in both the conventional FM steels and the RAFM steels [26][27][28][29][30][31][32][33][34][35][36] . M 23 C 6 endures amorphization at low irradiation temperatures [ 26 , 27 , 29-32 ] and coarsening at high irradiation temperatures [28] .…”

“…M 23 C 6 endures amorphization at low irradiation temperatures [ 26 , 27 , 29-32 ] and coarsening at high irradiation temperatures [28] . At low irradiation temperatures (below 300 °C), the MX phase was reported to be stable under high energy neutron irradiation [ 32 , 37 ], while a decrease in size and even disappearing under ion [38] and electron [35] irradiation. At high irradiation temperatures, MX transforms to Z-phase, Cr(V,Nb)N [39] .…”