Influence of Neutron and Electron Irradiation on Structural-Phase Transformations in Fe–12Cr–2W–V–Ta–B Steel Processed under Various Heat Treatment Conditions

The effect of electron and neutron irradiation and post-radiation annealing on the properties of 12% chromium ferritic-martensitic low-activated EK-181 steel treated under various heat conditions has been studied using transmission electron microscopy and resistometry. Both electron and neutron irradiation of EK-181 steel in the 300–340 K temperature range result in radiation-induced solid solution separation during all subsequent heat treatments. Isochronous annealing in the 300–500 K temperature range causes additional solid solution separation. Nanoclusters of point defects with a size from 1.5 to 5 nm and a concentration of 5 × 10 16 cm –3 have been observed after neutron irradiation at a fluence of (1–5) × 10 19 cm –2 . Thermal homogenization of the solid solution occurs above 650 K.