Effects of rolling and heat treatment on the mechanical properties and structure of a U-2 Mo alloy produced by co-reduction

Two U-Mo alloy billets (250 to 300 kg) of nominal composition U-2/sup w/0 Mo produced on a commercial scale by a direct co-reduction process at British Nuclear Fuels Ltd, were sectioned and fabricated by rolling, either in the α + γ phase region (600 to 6300C), or at γ phase temperatures (750 to 8000C) to various percentage reductions. Specimens from the resulting sheet or plate were subjected to a variety of heat treatments to examine the range of hardness and tensile properties that could be obtained, UTS values ranged from 112,000 to 217,000 psi and elongation values from 1 to 31%. A useful combination of properties achieved by a γ quench and ageing treatment, was 420 VPN hardness, 131,000 psi .2% YS, 184,000 psi UTS, 17% elongation, and 25% reduction in area. Tests at high strain rates (103 sec-1) produced a marked increase in flow stress and only a limited reduction in ductility