Effect of Implanted Helium on the Physicomechanical Properties of Armco Iron at the Temperatures of Manifestation of the Blue Brittleness Effect

The regularities and features of dynamic deformation aging of Armco iron samples uniformly in volume implanted with helium to a concentration of ~10 –3 at % He under irradiation with α particles with an energy of 50 MeV were studied. Unirradiated and irradiated samples were deformed by tension at a rate of 8.3 × 10 –4 s –1 at temperatures of 295–475 K, and the mechanical properties and energy characteristics—strain work, dissipated heat, and total stored energy—were determined. It was shown that, under tension in the temperature range of 350–600 K in the unirradiated and in the irradiated material, the process of dynamic deformation aging occurred. The effect of increase in the ductility of iron implanted with helium in the temperature range of 425–475 K, accompanied by additional heat release, was discovered. The increase in the plasticity of iron implanted with helium is explained by the formation of complex clusters containing helium atoms, vacancies, and impurity atoms, which leads to the clearing of the matrix of interstitial atoms and facilitating the movement of dislocations.