Hardening of an ODS Ferritic Steel after Helium Implantation and Thermal Annealing

摘要

In advanced nuclear reactors,helium can inevitably be produced via(n,)reaction and may precipitate into nano-scale helium bubbles in materials,and can causes degradation of material properties.In the present study,effects of helium bubbles formation in an oxide dispersion strengthened(ODS)steel is studied.Specimens of an ODS ferritic steel(15Cr-4Al-0.6Zr-0.1Ti)were implanted with mutiple-energy He ions at room temperature at the terminal of the 320 kV High-voltage Platform in IMP,to create a damage plateau of 0.4 dpa for average(corresponding to an He concentration of about 7000 appm)from the near surface to a depth about 1m.The specimen was subsequently thermally annealed at 800℃for 1 h in vacuum so that simple defects formed in the as-implanted state underwent significant recombination,meanwhile helium bubbles at nano-scale were formed.