Structural heredity in the U-6Nb alloy and conditions for its elimination

• Published in: Physics of metals and metallography Vol. 114; no. 4; pp. 299 - 307
• Main Authors: Sagaradze, V. V., Zuev, Yu. N., Bondarchuk, S. V., Svyatov, I. L., Shestakov, A. E., Pecherkina, N. L., Kabanova, I. G., Klyukina, M. F.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01-04-2013; Springer; Springer Nature B.V
• Subjects: Alloys; Chemistry and Materials Science; Deformation; Diffusion; Eutectoid decomposition; Genetics; Heat treatment; Heredity; Martensite; Materials Science; Metallic Materials; Phase Transformations; Quenching; Recrystallization; Specialty metals industry; Structure; Transformations; Uranium; Uranium base alloys; martensitic transformation; uranium-niobium alloy; α phase; refinement of grain of the γ phase; γ phase; structural heredity; restoration of grain of the γ phase upon heating
• ISSN: 0031-918X; 1555-6190
• DOI: 10.1134/S0031918X1304008X

The conditions have been determined for the manifestation of structural heredity in the U-6 wt % Nb alloy with the restoration of the size and shape of grains of the initial high-temperature γ phase in the course of the forward γ → α″ martensitic transformation upon cooling and the reverse α″ → γ transformation upon heating. Contrary to iron-based alloys, the restored γ phase does not undergo recrystallization due to phase-transformation-induced deformation (phase naklep) upon subsequent high-temperature heating. The elimination of structural heredity with a noticeable grain refinement (by almost an order of magnitude, down to 10–20 μm) in the high-temperature γ phase occurs in the process of the repeated quenching from 700°C after the use of one of the preliminary heat treatments (cold deformation of the α″ martensite, the recrystallization of the deformed α″ phase, the high-temperature aging of the initial α″ martensite, and eutectoid decomposition).