Document Type:Technical Results
This product is available at no cost to funding members only. If you are a member, you must Log in to access.
Price:$ 10,000 (US Dollars)
If you are a non-funding individual or entity and wish to purchase this document, please contact the EPRI Order Center at 1-800-313-3774 Option 2 or 650-855-2121. You may also send an e mail to firstname.lastname@example.org.
A comprehensive study was conducted to develop and deploy small-scale mechanical testing to evaluate localized failure in ion-irradiated (proton-irradiated) stainless steel. 304SS specimens in the as-irradiated (10 dpa full-cascade, 360oC), post-irradiation annealed, and unirradiated conditions are the focus of this work. All techniques applied (nanoindentation, microcompression, and microtensile testing) are in good agreement and, depending on the technique, one can quantify the change in hardness/yield strength, change in plasticity, and localized failure susceptibility. Nanoindentation can only access hardness and, indirectly, yield stress. In contrast, microcompression tests can provide partial stress strain curves and microtensile tests can be used to obtain entire stress-strain curves. The distinction arises because a tensile test has a well-defined point of failure whereas a compression tests does not; therefore, uniform and total elongation (to failure) can be obtained in a tensile test. Both of these techniques have clearly defined test volumes in comparison to nanoidentation. This advantage was demonstrated by locating the proton stopping-peak region (~100 dpa), which is ~1 mm wide, within a micropillar approximately 1.7 mm in diameter, to assess its mechanical behavior. The effective test volume of a “nanoindent” would be too large to isolate the mechanical behavior of such a narrow region.
A key result of this study is that the as-irradiated condition, which is susceptible to localized failure, releases significantly more energy per slip event than the post-irradiation annealed and the unirradiated conditions, which are much less susceptible or not susceptible. The average (energy/slip event) can be quantified and compared to the energy associated with the Peierls stress moving a dislocation across the sample width. The average number of (dislocations/slip event) and the observed magnitude of slip steps for the different conditions are in good agreement
For further information about EPRI, call the EPRI Customer Assistance Center at (800) 313-3774 or email email@example.com