Abstract
Tensile tests were carried out on an annealed, unirradiated V-4Cr-4Ti alloy from RT to 850 °C at strain rates ranging from 10-1 to 10-5 s-1. Below 300 °C, where interstitial solutes are relatively immobile, deformation is homogeneous, and the strain rate sensitivity (SRS) of the yield and flow stress is positive. Between 300 °C and 700 °C, the formation of solute atmospheres at locked dislocations results in dynamic strain-aging (DSA), deformation becomes heterogeneous, and the SRS of the flow stress is negative; in this regime the lower yield stress is independent of strain rate. Above 700 °C, substitutional solutes are also mobile, DSA declines, and the material enters a power law creep regime in which the SRS becomes positive again. Following neutron irradiation to 0.5 dpa at temperatures ≤400 °C, severe flow localization occurs due to the high number density of 〈110〉 and 〈111〉 loops. However, above 400 °C, strain hardening capacity returns but without the Luders extension. At 500 °C, after several percent plastic deformation, DSA occurs as interstitial solutes are released from the defect structure.
Original language | English |
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Pages (from-to) | 508-512 |
Number of pages | 5 |
Journal | Journal of Nuclear Materials |
Volume | 283-287 |
Issue number | PART I |
DOIs | |
State | Published - Dec 2000 |
Funding
The authors acknowledge the efforts of C.O. Stevens in carrying out the tensile tests with care and attention to detail. This research was sponsored by the Office of Fusion Energy Sciences, US Department of Energy under contract DE-AC05-96OR22464 with Lockheed Martin Energy Research Corporation.