U-Fe系合金の相変態と熱処理, (II)

抄録

The kinetics of isothermal transformation were studied with uranium alloys varying in iron content 0.51.0 _??_. Two modes of β-to-α transformation, nucleation-and-growth and martensitic transformations, are observed and M_s temperature is determined as a function of iron content. The M_s temperature increases with decreasing iron content, so the martensitic transformation, which produces coarse α-uranium grains, prevails in such alloys of lower content of iron. Nucleation and growth mode is found to be applicable to grain-refinement. And suitable grain-refinement is generally attained by isothermal transformation in the temperature region from 450°C to M_s temperature.