b'(d)(e)Project Description: recombination sites for self-interstitialFigure 2. Ultrafine intralath vanadium The recent identification of N asatoms (SIAs) and transmutation He.carbonitrides V(C,N) in the High N a potential element of interest forInitial characterization efforts also ledalloy. (a) shows two variants of strongly diffracting V(C,N) in a bright field (BF) controlling the irradiation resistanceto the development of a new high- TEM image taken slightly off of the of FM steel has led to the detailedthroughput method for comparing the[100] Body Centered Cubic (BCC)-investigation of how the irradiatedrelative amount of vanadium carbo- Fe zone axis. Selected areas (SAs) 1 microstructure and hardness changenitride and interstitial N in FM steelsand 2 correspond to the selected area diffraction patterns (SADPs) in (b) and with increased N content. Initial char- utilizing time-of-flight secondary ion(c) respectively, which have the relevant acterization of HT9 alloys containingmass spectrometry (ToF-SIMS). Notdiffraction spots circled for the two low (10 ppm), mid (190 ppm), andonly will the method be useful forvariants of V(C,N) visible in (a). (d) and high (440 ppm) N led to the first-timefuture irradiation studies interested in(e) show that the ultrafine precipitates in the irradiated alloy are still organized in observation of ultrafine (10 nm)changes in precipitates volume frac- clusters of smaller particles (indicated vanadium carbonitride precipitatestion, but the method is also applicablewith arrows) forming along the habit (shown in Figure 1) that changeto other steels research, e.g., nitridingplane. (d) and (e) are Centered Dark Field-Transmission Electron Microscopy morphology and volume fractionfor wear applications or rapid heat(CDF-TEM) images taken with the with increasing N content (shown intreatment optimizations. The threediffraction spots circled in (b) and (c).Figure 2). It is hypothesized that if thealloys were then irradiated to a dose of ultrafine precipitates are stable under1 dpa with 1.5 MeV protons at 300C. irradiation, they could act as sink/ Analysis of the steels post-irradiation 2021|AFC ACCOMPLISHMENTS 109'