Irradiation hardening of high-Cr ODS ferritic steels under helium implantation and heavy-ion irradiation

The present work investigates the irradiation hardening of ODS ferritic steels after multi-energy He-ion implantation, or energetic Bi-ion and Xe-ion irradiation, to get an understanding of dependence of irradiation-hardening on atomic displacement damage and gas accumulation. Three kinds of high-Cr ODS ferritic steels including the commercial MA956 (19Cr-3.5Al), the 16Cr-0.1Ti and the 16Cr-0.1Zr ODS ferritic steels were used. The results show that the hardness increases rapidly at the lower doses but tends to saturate at the higher dose. An 1/2-power law dependence on dpa value is obtained. Helium implantation contributes significantly to the irradiation hardening, possibly due to the impediment of the motion dislocations by helium bubbles. 16Cr-ODS (Ti or Zr added) ferritic which contains finer oxide particles in higher number density shows higher resistance to irradiation hardening than the MA056. (authors)