Microstructure and mechanical properties of V–Me(Cr,W)–Zr alloys as a function of their chemical–thermal treatment modes

Formation of regularities of the nanometric oxide precipitates and defect microstructure in vanadium-based low activation alloys V–Cr–Zr–(C,N,O) and V–Cr–W–Zr–(C,N,O) as a function of the regimes of their thermochemical treatment was investigated. Several methods of internal oxidation which provide formation of the nanosized ZrO2 particles of controllable dispersion, ensure the nanometric size of the heterophase structure to be maintained up to the temperatures as high as 1300–1400 °С, and allow the recrystallization temperature to be increased up to ≥1400 °С were proposed. Formation of such microstructure contributes to dispersion- and substructural hardening and results in more than twofold increase in the yield stress of these alloys both at room and elevated (800 °С) temperatures, compared to the conventional thermo-mechanical treatment