Recovery and radiation- and anneal-hardening of neutron-irradiated iron alloys

Experimental data are given on the annealing influence at 450...700 K on the mechanical properties such as temperature of brittleness Tsub(K) of ternary iron alloys with nitrogen (0.12...0.17% by mass) and some other substitutional elements (Mn, W, Ta) irradiated by neutron fluence up to 4...5x1019 neutr./cm2, energy E<0.5 MeV at the temperature of Tsub(F)=325 K. On the behaviour of nitrogen in solid solution, depending on alloying elements forming nitrides, one may judge on the effect of dynamic deformation ageing (DDA). For the DDA characteristics were assUmed the hight and the temperature maximum σsub(B). The correlation between the action of DDA, Tsub(k) and σsub(T) recovery at afterradiation annealing and the changes of a degree o, brittleness of Tsub(F) increasing up to approximately 480 K was pointed out. The obtained results were explained by displacement atoms influence on generation of vacancy-impurity clusters which dissociated up to 600 K of heating and on the process of the reverse transition into the solution of nitrogen atoms in the annealing interval of 600...700 K