Fabrication and Tensile properties of Oxide Dispersion Strengthened Stainless Steels Containing Gadolinium Oxide for Neutron Absorbing Structural Applications

Gadolinium has a neutron absorption capacity approximately 67 times higher than boron. However, because of its poor solubility in the Fe-Cr matrix, Gd tends to form brittle intermetallic phases, which significantly reduces ductility and corrosion resistance. To retrieve this problem, Gd2O3 employed as functional phase, because oxides are extremely stable and effectively inhibit the formation of undesirable phases. Furthermore, uniformly distributed oxide particles can play a role as strengthening phase and this is one of the promising methods to enhance mechanical properties at elevated temperatures. In this study, fine Gd2O3-dispersed stainless steels were fabricated by mechanical alloying, hot isotactic pressing processes. Thin sheets were successfully fabricated with cold rolling and intermediate heat treatment. And then, microstructures and tensile properties were systematically investigated. Experimental results suggest the potentiality of ODS stainless steels for neutron-absorbing structural materials with favourable neutron absorption capacity, mechanical properties and corrosion resistance.