High-energy neutron irradiation effects on the tensile properties and microstructure of 316 stainless steel

Abstract Type-316 stainless steel was irradiated at room temperature with 14-MeV, Be(d,n), and fission-reactor neutrons. Highenergy neutron irradiations were carried out at the Rotating Target Neutron Source (RTNS-I) at the Lawrence Livermore Laboratory and the 1.93-m Isochronous Cyclotron at the University of California at Davis. Irradiations with fission-reactor neutrons were carried out in the Lawrence Livermore Pool Type Reactor (LPTR). Tensile properties after irradiation were determined at room temperature, and significant changes in strength and ductility were found. Irrddiation at all three neutron sources produced a very high density of defects 1 to 2 nm in diameter. The 14-MeV neutrons created more damage on a fluence basis, but the mechanical property and microstructure data could be correlated well on a damage energy basis. The deformation behavior was in accord with the dispersed barrier model of radiation hardening.