Defect Microstructure and Irradiation Strengthening in Fe/Cu Alloys and Cu Bearing Pressure Vessel Steels

Abstract

The nature of the radiation damage and its dependence on Cu concentration have been studied in a series of Fe- Cu alloys and Cu containing pressure vessel steels, irradiated to 7 x 10¹⁹ n/cm² (E > 0.1 MeV) at 290 °C, using a combination of TEM, SANS, and compression testing. The magnitude of the irradiation hardening in the Fe-Cu- alloys is found to increase with the concentration of Cu in solution prior to irradiation, and is shown to be due to the formation of (i) Cu precipitates, and (ii) a finer dislocation loop distribution than in Cu-free Fe. Preliminary SANS measurements on a series of pressure vessel steels show that the defect microstructures formed during irradiation are more complex than in Fe-Cu alloys.