February 15, 2004
Journal Article

The effect of oversized solute additions on the microstructure of 316SS irradiated with 5 MeV Ni++ ions or 3.2 MeV protons

Abstract

The effect of the oversized hafnium or platinum (0.3at.percent) solutes on the evolution of irradiated microstructure in 316SS was investigated. Irradiations were conducted with 5 MeV Ni-ions at 500 degrees C to doses up to 50 dpa or with 3.2 MeV protons at 400 degrees C to a base of 2.5 dpa, and previous studies demonstrated that these irradiations are capable to produce similar irradiated microstructure and microchemistry relevant to LWR cores. Microstructures of 316SS, 316SS + 0.3 at.percent Pt and 316SS + 0.3 at.percent Hf were characterized using transmission electron microscopy. The addition of Hf showed a strong effect in suppressing radiation-induced microstructure evolution; no voids were observed at doses up to 50 dpa for Ni-ion irradiation and 2.5 dpa for proton irradiation. The mean diameter of the Frank loops in the Hf-doped samples is about 50 percent smaller than loops in irradiated 316SS and 316SS +Pt. The microstructure examinations from both types of particle irradiation revealed that for 0.3 at.percent Pt addition there is no beneficial effect on irradiated microstructure, although beneficial effects on grain boundary chemistry during proton irradiation were observed. The mechanisms for the role of oversize solute additions on the microstructure evolution are discussed. Differences between irradiation responses for Hf-doped and Pt-doped alloys suggest that the influence of size-misfit is more profound than mass-misfit.

Revised: March 9, 2009 | Published: February 15, 2004

Citation

Gan J., E.P. Simonen, S.M. Bruemmer, L. Fournier, B.H. Sencer, and G.S. Was. 2004. The effect of oversized solute additions on the microstructure of 316SS irradiated with 5 MeV Ni++ ions or 3.2 MeV protons. Journal of Nuclear Materials 325, no. 2-3:94-106. PNNL-SA-37301. doi:10.1016/j.jnucmat.2003.11.002