Effects of phosphorus on defects accumulation and annealing in electron-irradiated Fe–Ni austenitic alloys

Pure austenitic alloy Fe–36% Ni and the same alloy doped with phosphorus (0.1% P) were irradiated with 5 MeV electrons at different temperatures (270–573 K). Using the methods of positron annihilation and residual resistivity it was shown that at the irradiation temperature of 270 K vacancies are mobile in both alloys and form vacancy clusters. In Fe–36Ni–0.1P alloy vacancy clusters are decorated with phosphorus atoms. After the irradiation at 423 K the decoration effect is not observed. At the irradiation temperature of 573 K the addition of phosphorus results in the suppression of vacancy supersaturation. A conclusion is made that, at the elevated irradiation temperatures, suppression of vacancy supersaturation occurs due to the interstitial–phosphorus interaction.