The hot deformation characteristics of GH4720Li alloy were studied at the temperature of 1 100--1 170 ℃ and strain rate of 0.01--1 s -1 using Gleeble hot compression tests. True stress-true strain curves and deformation microstructures were investigated. Constitutive equation was established using the hyperbolic law. Processing map for hot working was also developed on the basis of the variations of efficiency of power dissipation with temperature and strain rate. The results show that dynamic recrystallization is the dominant softening mechanism during hot deformation. Fully recrystallized grain is obtained at strain of 0. 7 above 1 130 ℃, and coarsening occurs above 1 150 ℃. The mean deformation activation energy is determined to be 512 kJ/mol. According to the low activation energy value, high dissipation efficiency parameter and fine recrystallized microstructure, 1 130 ℃ is chosen as the hot working temperature for GH4720Li alloy.
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