2018 | AFC ACCOMPLISHMENTS 145 Figure 1. Comparison of yield stress (left) and fracture toughness (right) for the HT-9 steel heat-3 after various heat treatments (note: AR = as-rolled; WQ = water quenched; WQ-300°C (for example) = water quenched and tempered at 300°C; FFTF = fact flux test facility).