MAPPING FLOW LOCALIZATION PROCESSES IN DEFORMATION OF IRRADIATED REACTOR STRUCTURAL ALLOYS - FINAL REPORT. Nuclear Energy Research Initiative Program No. MSF99-0072. Period: August 1999 through September 2002. (ORNL/TM-2003/63)

Influence of localized deformation on A-286 austenitic stainless steel stress corrosion cracking in PWR primary water

“…Indeed, A-286 c 0 mean diameter and density of respectively, 4.6 nm and 1.6 · 10 23 m À3 used in this study are similar to Frank loops mean diameter and density in neutron-irradiated stainless steels reported by Bruemmer et al [37] (8 nm and 1.6 · 10 23 m À3 at 3 dpa for an irradiation at 280°C) and Pokor et al [38] (7 nm and 6 · 10 22 m À3 at 3 dpa for an irradiation at 330°C). Also, as displayed in Table 4, c 0 precipitate-free channels obtained after 120 fatigue cycles with a mean width and spacing of respectively 30 nm and 550 nm, are similar to channels mean width and spacing reported by Farrell et al [39] in neutron-irradiated 316 SS at 65-100°C to 0.78 dpa and deformed to 2% strain (26 nm and 622 nm). Finally, as shown in Figs.…”

Modeling tensile response and flow localization effects in selected copper alloys

“…Fig. 3 shows the relationship between yield strength and uniform elongation for OFHC copper and selected copper alloys and includes similar data for 316SS from more detailed studies of that alloy system [3][4][5][6][7]. It is apparent that, within the limits of the scatter in tensile testing results, there are clear linear relationships between yield strength and uniform elongation for the copper alloys.…”

“…This work concentrates on limited ductility and flow localization in irradiated copper alloys by Edwards and co-workers [1,2]. For irradiated 316SS, two major studies on flow localization effects in 316SS, one by Pawel-Robertson and co-workers [3,4] and a second recent study by Farrell et al [5] were examined.…”

Microstructures Of Irradiated And Mechanically Deformed Metals And Alloys: Fundamental Aspects

“…A general feature associated with irradiation at low temperature (below ~0.3 T M ) is increased matrix hardness and decreased ductility due to the presence of radiation-induced defects which act as obstacles to dislocation motion, irrespective of alloy type or crystal structure. Figure 9 shows cleared dislocation channels that formed in Type 316 austenitic stainless steel following irradiation to 0.78 dpa at 70˚C and tensile deformation at room temperature [46]. Dislocation channeling occurs because the radiation-induced defect clusters present at these low temperatures can be readily cut by gliding dislocations (dislocation barrier strength of α~0.1-0.25, as opposed to 0.8 for impenetrable Orowan obstacles).…”

“…Based on systematic studies investigating surface slip lines and TEM microstructures in irradiated and deformed metals, the loss of ductility has been attributed to dislocation channeling [41][42][43][44]. Dislocation channels have also been observed in irradiated ferritic/martensitic steel [47] and other engineering alloys [46] following deformation. This produces a defect-free path for subsequent dislocations emitted from the operating source.…”