Mechanically Alloyed-Oxide Dispersion Strengthened Steels for Use in Space Nuclear Power Systems

Abstract

The mechanical and thermo‐physical properties of Mechanically Alloyed (MA)‐Oxide Dispersion Strengthened (ODS) steels are reviewed and their potential for use in space nuclear reactor power systems is examined. The three MA‐ODS alloys examined are Inconel MA‐ODS754 (77.55Ni, 20Cr, 1Fe, 0.5Ti, 0.3Al, 0.05C, and 0.6Y2O3), Incoloy MA‐ODS956 (74.45Fe, 20Cr, 4.5Al, 0.5Ti, 0.05C, 0.5Y2O3), and Incoloy MA‐ODS957 (84.55Fe, 14Cr, 0.3Mo, 0.9Ti, 0.25Y2O3). The major advantages of these alloys are: (a) their strength at high temperatures (>1000 K) is relatively higher and decreases slower with temperature than niobium (Nb) and molybdenum (Mo) refractory alloys; (b) they are relatively lightweight and less expensive; (c) they have been shown to experience low swelling and embrittlement with exposure to high‐energy neutrons (> 0.1 MeV) up to a fluence of 1023 n/cm2; and (d) their high resistance to oxidation and nitration at high temperatures, which simplifies handling and assembly. These MS‐ODS alloys are also lighter...