Tóm tắt

The hot deformation behavior of b-quenched Zr–1Nb–1Sn was studied in the temperature range 650–1050 u0002C and strain rate range 0.001–100 su00021 using processing maps. These maps revealed three different domains: a domain of dynamic recovery at temperatures <700 u0002C and at strain rates <3 · 10u00023 su00021, a domain of dynamic recrystallization in the temperature range 750–950 u0002C and at strain rates <10u00022 su00021 with a peak at 910 u0002C and 10u00023 su00021 (in a + b phase field), and a domain of large-grain superplasticity in the b phase field at strain rates <10u00022 su00021. In order to identify the rate controlling mechanisms involved in these domains, kinetic analysis was carried out to determine the various activation parameters. In addition, the processing maps showed a regime of flow instability spanning both a + b and b phase fields. The hot deformation behavior of Zr–1Nb–1Sn was compared with that of Zr, Zr–2.5Nb and Zircaloy-2 to bring out the effects of alloy additions.